METHOD AND PROTOCOL OF ACCESS IN AN AD HOC NETWORK

专利摘要:
Method for accessing a radio channel in a communication system comprising a plurality of terminals communicating with each other by radio links, a terminal being equipped with transmission and / or reception means, with a processor adapted to perform the steps of the method , characterized in that it uses an access protocol based on a communication frame (F) composed of several slots S (1), S (S + 2), the first S slots each comprising two mini-slots, the first mini-slot comprising an RTS data transmission request signaling message or data, the second mini-slot comprising a "ready to receive" signaling message, CTS, or data, the slot (S + 1 ) containing an RTS-type message or data, the slot (S + 2) containing a CTS-type message and an acknowledgment message placed at the end of the frame to acknowledge one or more transmissions taking place on the channel radio.
公开号:FR3031271A1
申请号:FR1403024
申请日:2014-12-30
公开日:2016-07-01
发明作者:Hicham Anouar
申请人:Thales SA；
IPC主号:

专利说明:

[0001] The invention relates to a method of communication and a protocol for accessing the radio channel of an ad hoc network. It applies to the field of ad hoc wireless communications networks and defines in particular a distributed access protocol to the radio channel that can reach the theoretical maximum capacity in the asymptotic regime. Mobile wireless ad hoc networks are characterized by the absence of a fixed infrastructure and the lack of complete mutual visibility of the nodes thus making any centralized control of access to the channel inappropriate. Historically, the ALOHA protocol is the first random access distributed channel access protocol based on a single-hop access network using radio channel packet switching. Channel access control is better known by the abbreviation "MAC" 15 or Medium Access Control. The ALOHA protocol allows each user to transmit data whenever he wants. If the sender receives a confirmation from the recipient of the good reception of a packet within a certain time, then he knows that no conflict has occurred. In the opposite case, at the end of this period it assumes that a collision has occurred and it must retransmit the packet. In order to avoid the continuous repetition of access conflicts, the retransmission delay is random, thus preventing users from transmitting or retransmitting at the same time. A synchronous version of ALOHA is obtained by dividing the time into intervals of time equal to the transmission time of a packet. When two packets 25 collide, then they overlap completely rather than partially, leading to an increase in channel utilization to 36% instead of 18% for asynchronous ALOHA. The main improvement in the design of random MAC protocols has been the introduction of the Carrier Sense Multiple Access (CSMA) multiple access listening technique. The CSMA protocol reduces the level of interference caused by packet collisions by allowing each terminal to pre-listen a channel and detect any transmissions in progress. The MAC protocol of the popular IEEE802.11 standard is widely used for wireless LANs, Figure 1A. It uses a channel-based multiple access scheme and a binary exponential window retransmission mechanism. In single-hop networks where all nodes see each other, the protocols based on the CSMA protocol achieve a very good use of the transmission or communication channel of the order of 80% [1] [2]. The lack of line of sight between all nodes in the network has a negative impact on the channel-based access protocols because of the hidden terminal problem illustrated in Figure 1B where a user A can communicate with a client. user B in radio range or visibility but can not communicate with a user C. In order to solve this problem of the hidden terminal, the IEEE 802.11 protocol, FIG. 1C, has defined a second access mechanism that makes a reservation of the channel in the neighborhoods transmitter and receiver. The reservation is obtained by the exchange of two signaling messages, a first request message to transmit known as RTS (Request To Send) and a second "ready to send" message known by the acronym "Anglo". -Saxon CTS (Clear To Send) blocking access to the channel for the terminals that receive them. The RTS / CTS mechanism aims to achieve reuse of the two-hop radio channel. However, the mechanism fails to solve the problem of the hidden terminal correctly because its correct functioning requires that the nodes of the network have access to all the reservation messages of their neighborhoods. This constraint is impossible to respect in multi-hop networks because of the problem of the hidden terminal. The problem of the masked terminal thus greatly degrades the performance of the protocol in multi-hop networks and this problem is accentuated when the size of the network increases because the number of hidden / masked terminals also increases. Figure 1C illustrates the problem of the masked terminal, C.
[0002] To the applicant's knowledge, no protocol in the literature defines a mechanism that can support maximum reuse of the channel, thus making it possible to reach the maximum transmission capacity of the channel and to reach the theoretical maximum capacity of a network. ad-hoc in the collision channel model. Indeed, in an optimal access mechanism, only the neighbors of the receivers can not access the channel. The invention particularly relates to a data transmission method, its access protocol for a synchronized network using a time division multiple access mode, known by the acronym "TDMA" or a mode of operation. similar access, in which the frame is divided into a set of time slots or "slots" which may contain either the RTS / CTS type reservation signaling or the data, or else an acknowledgment signal for good reception of data or end of transmission. In the remainder of the description, the following symbols are used: DATA to designate data, GIS for signaling, RTS for the request to be transmitted or Request To Send, CTS for the ready-to-transmit state or "Clear To Send", ACK for acknowledgment, P-ACK for partial acknowledgment, CAC for confirmed channel access. In the case of simple variants, the following letters, for example, will be used to designate the frames and slots involved: F for a frame, S for a slot, MS for a mini-slot, MF for a mini-frame, [F , SIG] for a signaling channel frame, [F, DATA] a data channel frame, [S, SIG] a slot on the signaling channel, [S, DATA] a data channel slot, [MS , SIG] a mini-signaling slot, [MS, DATA] a mini-slot of the data channel, GS for macro-blocks, GF for macrotrames, etc. The added indices will designate the rank of a slot or other, for example MS1 is a first slot of a slot.
[0003] 3031271 4 We will use the word node or terminal to designate the same object, a mobile radio station. References 10e designate a transmitting node or wishing to transmit, 10r a destination or receiver node. The invention relates to a method for accessing a radio channel in a communication system comprising several terminals communicating with each other by radio links, a terminal being equipped with transmission and / or reception means, a suitable processor to execute the steps of the method, the method is characterized in that it uses an access protocol based on a communication frame composed of several slots, the first S 10 slots each comprising two mini-slots, the first mini-slot comprising an RTS data transmission request signaling message or data, the second mini-slot comprising a "ready to receive" signaling message, CTS, or data, the penultimate slot containing a message of the type RTS or data, the last slot 15 containing a message type CTS and an acknowledgment message placed at the end of the frame to acknowledge one or more transmissions taking place on the radio channel. According to one embodiment, a frame F is divided into (M + 1) mini-frames, each mini-frame having the aforementioned structure of the frame 20 and for the first M mini-frames, the first slot of the last slot contains a CTS message or a P-ACK partial acknowledgment message. The method implements, for example, at least one GIS signaling channel separate from a data channel DATA and the signaling channel takes up the mini signaling slots RTS and CTS, the last slot on the signaling channel. is not used, the data channel DATA takes over the data slots and an acknowledgment slot ACK at the end of the frame. According to another variant, the method comprises at least one signaling channel that is distinct from a data channel, a frame is divided into (M + 1) mini-frames and, for the GIS channel, M first mini-frames are used. each composed of (S + 2) slots, the (S + 1) slots are each composed of a mini-slot for RTS messages and a mini-slot for messages 3031271 5 CTS, the last slot contains a mini -slot for partial acknowledgment messages P-ACK and a neutralized mini-slot, on the DATA channel, we use M first mini-frames each composed of "S + 2" slots, the "S + 1" first slots are for data messages, the last slot "S + 2" 5 is composed of a neutralized mini-slot and a mini-slot for acknowledgment messages ACK. The frame F on the signaling channel SIG is composed, for example, at the level of the "S + 1" first slots, three mini-slots distributed in the following manner, a first mini-slot for sending RTS messages, 10 a second mini-slot for sending CTS type messages, a third mini-slot for sending CAC type messages. The method may use a frame composed at the first "S + 1" slots of each mini-frame on the signaling channel of three mini-slots distributed as follows, a first mini-slot for sending the messages. RTS, a second mini-slot for sending CTS type messages, a third mini-slot for sending CAC type messages, the last slot of the first M mini-frames on the GIS signaling channel is modified to contain three mini-slots: the first for sending messages type P-CAC, the second for sending messages type 20 P-ACK, and a third mini-slot unused, the last slot of the M first mini-frames on the data channel DATA is modified to contain three mini-slots: the first two mini-slots are not used and the third mini-slot is reserved for sending ACK messages. According to an alternative embodiment, the frame F is supported by 25 "Ns + Nd" distinct radio channels (frequency, code, etc.): "Ns" SIG channels and "Nd" DATA channels where "Nd" is a multiple of "Ns": "Nd = P * Ns", on the GIS channels, the frame contains "S + 1" signaling macro-slots RTS / CTS and a last slot not used, each of the signaling macro-slots is composed of "P" slots, and each slot is itself composed of two mini-slots; The first mini-slot carries messages of the RTS type and the second mini-slot carries messages of the CTS type; The "i" th slot 3031271 6 of each macro-slot on the "n" th signaling channel is used for the exchange of RTS / CTS reservation signaling to access the "d" th data channel such that "d = (n-1) * P + i "; On the DATA channels, the frame contains "S + 1" macro-slots of DATA and a last acknowledgment slot ACK, each of the macro-slots of DATA is itself composed of "P" DATA slots. It is possible to use a frame supported by "Ns + Nd" distinct radio channels (frequency, code, etc.): "Ns" SIG channels (signaling) and "Nd" DATA channels (data), where "Nd" is multiple "Ns": "Nd = P * Ns"; on the GIS channels, the frame is divided into "M + 1" (M> = 0) mini-frames, the last mini-frame takes exactly the form of the GIS frame described above, on the GIS channels , each of the first "M" mini-frames is composed of "S + 2" macro-slots: "S + 1" macro-signaling slots RTS / CTS and a last macro-slot signaling P-ACK, each of 15 "S + 1" macro-signaling slots RTS / CTS is composed of "P" slots, and each of the "P" slots is itself composed of two mini-slots; The first mini-slot carries messages of the RTS type and the second mini-slot carries messages of the CTS type, the P-ACK signaling macro-slot is composed of "P" slots which carry messages of the P-ACK type and 20 last slot not used; The "i" th slot of each macro-slot of each mini-frame on the "n" th GIS channel is used for the RTS / CTS reservation signaling exchange to access the "d" th DATA channel such as "d". = (n-1) * P + i "; The "i" th slot of the last P-ACK macro-slot of each mini-frame on the "n" th GIS channel is used to send P-ACK message corresponding to the DATA channel "d" such as "d". = (n-1) * P + i "; On the DATA channels, the frame also contains "M + 1" (M> = 0) mini-frames; the last mini-frame takes the form of the DATA frame described above; On the DATA channels, each of the first "M" mini-frames is composed of "S + 2" macro-slots: "S + 1" macro-slots of DATA and a last 30 macro-signaling slot ACK; each of the "S + 1" macro-slots of DATA is composed of P DATA slots, the macro-signaling slot ACK is 3031271 7 composed of "P" unused slots and a last slot ACK to carry messages of type ACK, the last mini-frame takes the form of the DATA frame described above. It is possible to modify the frame on the GIS channels such that each slot of the macro-slots is composed of three mini-slots: a first mini-slot for sending the RTS messages, a second mini-slot for sending CTS messages, and a third mini-slot for sending a CAC message. According to an alternative embodiment, the frame is modified on the 10 signaling channels in such a way that each slot of the "S + 1" first macro-slot of each mini-frame on the signaling channels is now composed of three mini-slots : a first mini-slot for sending RTS messages, a second mini-slot for sending CTS messages, and a third mini-slot for sending a message type CAC, the last 15 macro- Slot of the first M mini-frames on the SIG channels is now composed of 2P + 1 slots: P slots P-CAC, P slots P-ACK, and a last unused slot, the last macro-slot of the first M mini frames on the channels of DATA is changed to contain 2P + 1 slots: 2P unused slots and a last slot ACK.
[0004] The invention also relates to a frame structure intended to be used in a synchronous network with TDMA access, comprising an "S + 2" number of slots, characterized in that its structure comprises at least the following elements: First slots each contain two mini-slots, the first mini25 slot contains a signaling message of type RTS or data, the second mini-slot contains a message signaling CTS or data, the first mini-slot of the penultimate Slot "S + 1" contains an RTS message or data, the second mini-slot of the penultimate slot "S + 1" contains data, the first mini-slot of the last slot contains a message of type CTS, The second slot of the last slot contains an acknowledgment message of the ACK type. Other characteristics and advantages of the invention will appear better on reading the following description of exemplary embodiments given by way of non-limiting illustration and appended figures which represent: FIGS. 1A, 1B and 1C, different protocols of the prior art and an illustration of the problem of the hidden terminal and the masked terminal, - Figure 2, a schematization of a communication network in which the invention can be implemented, - Figure 3A, a first exemplary protocol, and FIG. 3B, a variant of the protocol of FIG. 3A in a multi-frame version, FIG. 4A, an alternative embodiment of FIG. 3A with a signaling channel and a separate data channel, and FIG. 4B, a variant with multi-frames; FIG. 5A, a protocol variant with a signaling channel and a separate data channel and validation of the RTS, and FIG. 5B, a multi-frame variant; FIG. 6A, a variant of the multichannel protocol and FIG. 6B, multi-frame, multichannel, FIG. 7A, a variant of FIG. 6A with validation of the RTS, and FIG. 7B, a variant of FIG. 6B with validation of the RTS. The following example is given as an illustration and in no way limiting in the case of an ad hoc network comprising several terminals 10n communicating together by radio links. A terminal 10n comprises transmission / reception means, 11n, 12n, a processor 13n adapted to perform the steps of the various process variants, a counter K. FIG. 3A represents a first example of a protocol according to FIG. 'invention. A synchronous network with access to TDMA is considered. Each frame F is composed of "S + 2" slots S (1), .., S (S + 2). The "S" 3031271 first 9 slots each contain 2 mini slots MS1 (s), MS2 (s). The first mini-slot MS1 (s) of each slot may contain either the RTS type of signaling message or DATA data messages. The second mini-slot MS2 (s) of each slot S may contain either the CTS-type message or DATA data messages. The first mini-slot MS1 (S + 1) of slot "S + 1" may contain the RTS type message or data. The second mini-slot MS2 (S + 1) can only contain data. The first mini-slot MS1 (S + 2) slot "S + 2" can only contain the message type CTS. The second mini-slot MS2 (S + 2) can contain only the acknowledgment message ACK type. A data transmission can take place at any slot of the frame but must necessarily end at the end of the frame where the data transmission started before the last slot. The implementation of the transmission method with this type of frame comprises the steps described below. Phase A A node that does not transmit, listens to the channel. If it detects a transmission on the second mini-slot MS2 (s) of one of the first "S" slots, it then prohibits all access to the channel until the end of the current frame Fc, frame used for 20 Communication. It thus becomes a blocked node on the current frame. If it detects a transmission on the first mini-slot MS1 (S + 2) of the slot "S + 2" of the current frame Fc, it then forbids any access to the channel until the end of the next frame Fs . It thus becomes a blocked node on the next frame. Phase B A node 10n that wishes to transmit data, draws a random number (a mechanism known as random Back-Off) and initiates a countdown K with the value of the drawn number: B.1 On the "S" first slots of the frame: B.1.a. The counter K is decremented at each slot s of the current frame 30 Fc if the node does not detect transmission over the entire slot, 3031271 10 B.1.b. The counter K is blocked at each slot s if the node detects a transmission on the first mini-slot (RTS or data), MS1 (s), B.1.c. The counter K is blocked until the end of the current frame Fc if the node correctly decodes an RTS message intended for it, B.1.d. The counter is blocked until the end of the frame Fc if the node detects a transmission on the second mini-slot (CTS or data), MS2 (s), B.2. On the "S + 1" th slot and the "S + 2" th slot of the frame Fc: B.2.a. The counter K is decremented once if the node does not detect transmission on the first mini-slot MS1 (S + 1) of the slot S + 1 and the first mini10 slot MS1 (S + 2) of the slot S + 2, B.2.b. The counter K is blocked until the end of the next frame if the node correctly decodes an RTS message intended for it, B.2.c. The counter K is blocked until the end of the next frame if the node detects a transmission on the first mini-slot (CTS), MS1 (S + 2).
[0005] Phase C When the counter K expires, when the value of the counter K reaches 0, the node sends a message of the RTS type to notify its desire to transmit to a destination node. This broadcast takes place: C.1. On the first mini-slot MS1 of the slot following the expiration of the counter K if the counter K expires in the "S" first slots of the frame Fc, C.2. On the first mini-slot MS1 of the next frame of the current frame Fc if the counter K expires at the slots "S + 1" and "S + 2" of the current frame Fc. Phase D 25 If the receiving terminal lOr correctly receives the request message to be transmitted RTS and if it is not blocked, then it responds by sending a message of the type CTS to indicate to the node issuer 10th that it is available for the reception. If the transmission of the RTS message takes place in one of the "S" first slots then the CTS message is sent on the second mini-slot (slot CTS) 30 MS2 (s) of this slot s. If the transmission of the RTS message takes place at the slot "S + 1" then the message CTS is sent on the first mini-slot (slot CTS) of the last slot "S + 2", MS1 (S + 2). Phase E E.1. If the transmitting terminal 10e of the RTS correctly receives the message CTS, then the transmission of the data begins at the next slot of the current frame Fc if the successful exchange RTS / CTS has taken place in one of the first "S" slots of the frame. , or the first slot of the next frame Fs if the RTS / CTS exchange took place at the last slots "S + 1" and "S + 2" of the current frame Fc. Thus, the communication can begin at any slot of the frame upon expiry of the counter K and after a successful RTS / CTS exchange, but it necessarily terminates at the end of the Fc frame or the Fs frame where the data transmission started just before the last slot, E.2. If the sending terminal 10e of the RTS does not receive the CTS message correctly, then it will be able to either abandon the current transmission of the data, or try to access the channel again by again following the steps from B to E until it receives correctly the CTS message. If the sending node fails to receive the CTS message after a predefined number of attempts then it abandons the current transmission of the data. Phase F A destination node 10r or receiver transmits on the last mini-slot MS2 (S + 2) of the frame a message of the acknowledgment ACK type, to inform the sending node 10e of the reception state of the data.
[0006] A first variant of multi-frame embodiment is shown schematically in FIG. 3B. We consider a synchronous network with access to TDMA. The frame is divided into "M + 1" (M> = 0) mini MF frames (f). The first "M" mini-frames are optional, the last MF mini-frame (F + 1) is mandatory and takes exactly the form of the basic frame described in Figure 3A. Each mini-frame is composed of "S + 2" slots.
[0007] The "S" first slots of each mini-MF frame each contain two mini slots MS1, MS2. The first mini-slot MS1 (s) of each slot s may contain either the RTS type of signaling message, or DATA type data messages. The second mini-slot MS2 (s) of each slot s may contain either the CTS type signaling message or DATA type data messages. The first mini-slot of the slot "S + 1" of each mini-frame [MS1 (S + 1), MF] may contain the RTS-type message or data. The second minislot [MS2 (S + 1), MF] can only contain data.
[0008] The last slot "S + 2" of a mini-frame MF is defined as follows: - In the "M" first mini-frames: the first mini slot of the slot "S + 2", MS1 (S + 2 ) of each MF mini-frame can contain CTS or P-ACK (Partial ACK) signaling messages. The second mini-slot "S + 2", MS2 (S + 2), can only contain the ACK type acknowledgment message. - In the last MF mini-frame (F + 1): the first mini slot [MS1 (S + 2), MF (F + 1)] of slot "S + 2" can only contain the message of type CTS . The second mini-slot [MS2 (S + 2), MF (F + 1)] can only contain the ACK type acknowledgment message. A data transmission may take place on one or more mini frames but must terminate at the end of one of the mini-frames of the frame where the data transmission has started. The steps associated with the transmission method implementing this type of frame are for example described below. Phase A A node that does not emit listens to the channel. If it detects a transmission on the second mini-slot of the "S" first slots of the mini-frame, [MS2 (s), MFc], then it forbids any access to the channel until the end of the mini - current frame, 30 mini-frame used for communication, it thus becomes a blocked node on the current mini-frame. If it detects a transmission on the first mini-slot 3031271 13 of the slot "S + 2" of the current mini-frame MFc, [MS1 (S + 2), MFc] it then forbids any access to the channel until at the end of the next mini-frame, it becomes a blocked node on the next mini-frame. Phase B A 10th node wishing to transmit data, draws a random number (a mechanism known as a random Back-Off) and initiates a countdown K with the value of the drawn number: B.1. On the "S" first slots of the mini-frame: B.1.a. The counter K is decremented at each slot of the current frame Fc 10 if the node 10e does not detect transmission over the entire slot, B.1.b. The counter K is blocked at each slot if the node 10e detects a transmission on the first mini-slot (RTS or data), [MS1 (s), Fc], B.1.c. The counter K is blocked until the end of the reception if the node 10e correctly decodes an RTS message intended for it, the end of reception 15 is indicated in the message RTS, B.1.d. The counter K is blocked until the end of the current mini-frame MFc if the node detects a transmission on the second mini-slot (CTS or data), MS2 (s), B.2. On the "S + 1" th slot and the "S + 2" th of the mini-frame: 20 B.2.a. The counter K is decremented if the node does not detect transmission on the first mini-slot MS1 (S + 1) of the slot S + 1 and on the first mini-slot MS1 (S + 2) of the slot S + 2, B.2.b. The counter K is blocked until the end of the reception if the node correctly decodes an RTS message intended for it, the end of reception 25 is indicated in the message RTS, B.2.c. The counter K is blocked until the end of the next mini-frame if the node detects a transmission on the first mini-slot (CTS or P-ACK), MS1 (S + 2). At the expiry of the counter K, when the value of the counter K reaches 0, the node 10e sends a message of the RTS type to notify its desire to transmit to a destination node. This broadcast takes place: C.1. On the first mini-slot following expiration if the counter K expires in the first 5 "S" slots of the current mini-frame MFc, C.2. On the first mini-slot of the next mini-frame if the counter K expires at the slots "S + 1" and "S + 2" of the current mini-frame MFc. Phase D If the destination terminal 10r correctly receives the request message to be transmitted RTS and if it is not blocked, then the destination node 10r responds by sending a message of the type CTS to indicate to the sending node that it is available for reception. If the transmission of the RTS message takes place in one of the first "S" slots, then the CTS is sent on the second mini-slot (CTS slot) of this slot MS2 (s). If the transmission of the RTS message takes place in slot 15 "S + 1", then the CTS is sent on the first mini-slot (CTS slot) of the last slot "S + 2", MS1 (S + 2). Phase E E.1 If the transmitting terminal 10e of the RTS correctly receives the message CTS, then data transmission starts at the next slot if the successful exchange RTS / CTS has occurred in one of the first "S" slots of the mini current frame, or the first slot of the next mini-frame if the RTS / CTS exchange took place at the last slots "S + 1" and "S + 2" of the current mini-frame. Thus, the communication can begin at any slot of the frame at the expiration of the counter and after a successful RTS / CTS exchange, and can span multiple mini-frames, but must end at the end of the frame. one of the mini-frames of the frame where the data transmission started. The transmitting node 10e indicates the last mini-frame of the data transmission in its RTS message. E.2. If the transmitting terminal 10r does not receive the CTS message correctly, then it may either drop the current data transmission or try to access the channel again by following the steps of E to receive the CTS message correctly. If the sending node 10e fails to receive the message CTS after a predefined number of attempts then it abandons the current transmission of the data. Phase F A recipient node 10r or receiver sends an ACK message at the end of the last transmission mini-frame and a P-ACK message at the end of each of the other intermediate mini-frames of the transmission. Figure 4A schematizes an exemplary implementation for a network in which the signaling channel and the data channel are separate, GIS channel and DATA channel. It is now considered that the TDMA frame of the basic version of the protocol is supported by two distinct radio channels (frequency, code, etc.): a signaling channel, GIS and a data channel, DATA. Based on FIG. 3A, the GIS channel includes the mini signaling slots RTS, [MS1, SIG] and CTS [MS2, SIG] organized in S + 1 slots, while the DATA channel takes over the S + 1s. data slots DATA, [S, DATA], and the slot ACK (last slot S + 2 of the DATA channel). The last S + 2 slot on the GIS channel is not used. The S + 1 signaling slots of the GIS channel correspond to the S + 1 data slots of the DATA channel. The last unused slot on the SIG signaling channel corresponds to the ACK slot of the DATA channel. The steps of the method using this variant of access protocol to the radio channel comprises the steps described below. Phase A A node that is not transmitting or receiving on the DATA data channel listens for the GIS signaling channel. A.1 If it detects a transmission on a mini-slot CTS (second mini-slot MS2 (s) slot s one of the "S" first slots then it prohibits any access to mini-slots RTS (first slot S1) of the SIG signaling channel until the end of the current frame Fc, it thus becomes a node blocked in transmission on the current frame Fc, 3031271 16 A.2. on the mini-slot CTS slot "S + 1", MS2 (S + 1), then it prohibits all access to mini-slots RTS signaling channel GIS until the end of the next frame Fs, it thus becomes a node blocked in transmission on the following frame Fs, A.3 If it detects a transmission on a mini-slot RTS (first mini-slot slot) of one of the "S" first slots, MS1 ( s), then it prohibits all access to minis CTS (second mini slot slot) of the signaling channel GIS until the end of the current frame Fc, it becomes a node blocked in reception on the current frame Fc , 10 A.4. detects a transmission on the mini-slot RTS slot "S + 1", MS1 (S + 1), then it prohibits all access to the mini-slots CTS signaling channel GIS until the end of the next frame Fs, it thus becomes a node blocked in reception on the following frame Fs. Phase B 15 B.1. A node 10e wishing to transmit, draws a random number and initiates a countdown, K, with the value of the drawn number, B.2. The counter K is decremented at each slot if the node 10e does not detect a transmission on the mini-slot CTS of the slot [MS2 (s), SIG], B.3. The counter K is blocked until the end of the current frame Fc if the node 10e correctly decodes an RTS message intended for it, B.4. On the first "S" slots of the frame Fc, the counter K is blocked until the end of the current frame Fc if the node 10e detects a transmission on the slot mini-slot CTS, [MS2 (s), SIG ]. B.5. On the slot "S + 1" of the frame Fc, the counter K is blocked until the end of the next frame Fs if the node 10e detects a transmission on the minislot CTS of the slot, [MS2 (S + 1) , SIG], B.6. The counter K is blocked during the slot "S + 2". Phase C At the expiry of the counter K, the node 10e sends a message of the RTS 30 type to notify its desire to transmit to the recipient. This transmission takes place on the GIS signaling channel, 3031271 17 C.1. On the first mini-slot of the slot following the expiry of the counter K, MS1 (s + 1), if the counter K expires in the "S" first slots of the frame, C.2. On the first slot of the first slot of the next frame Fs if the counter expires at slot "S + 1" of the current frame Fc.
[0009] If the receiving terminal 10r correctly receives the request message RTS to transmit and if it is not blocked in reception, then the destination node 10r responds by sending a message of the type CTS to indicate to the node 10th transmitter that it is available for reception. The transmission of the message CTS 10 takes place on the second mini-slot (slot CTS) of the slot where the transmission of the message RTS, MS2 (s, RTS) took place. Phase E E.1. If the transmitting terminal 10e of the RTS correctly receives the message CTS, then the data transmission starts, on the DATA channel, at the next slot (s + 1) if the successful exchange RTS / CTS has taken place in one of the "S" First slots of the frame, or the first slot S1 (Fs = Fc + 1) of the next frame Fs if the RTS / CTS exchange took place at the slot "S + 1" of the current frame Fc. Thus, the communication can start at any slot of the frame upon expiry of the counter K and after a successful RTS / CTS exchange, but it necessarily ends at the end of the frame where the data transmission has started. just before the last slot, E.2. If the transmitting terminal 10e does not receive the CTS message correctly, then it will be able to either abandon the current transmission of the data or try to access the channel again by again following the steps of the phases C to E until it receives correctly the CTS message. If the sending node 10e fails to receive the message CTS after a predefined number of attempts then it abandons the current transmission of the data. Phase F A receiver node 10r sends on the DATA channel, on the last slot (S + 2) 30 of the current frame Fc, a message of the ACK type to inform the transmitter of the state of reception of the data.
[0010] Figure 4B shows a variant in the case of MF multi-frames on a separate signaling channel and data channel. The frame F is divided into "M + 1" (M> = 0) mini-frames MF (1), .., MF (M + 1). The first "M" mini-frames are optional, the last MF mini-frame (M + 1) is mandatory and exactly takes the form of the frame of the variant described in Figure 4A. The SIG signaling channel takes over the RTS, CTS, and P-ACK signaling slots while the DATA data channel takes over the data slots and the ACK slots. On the GIS signaling channel, the first "M" mini MF frames are each composed of "S + 2" slots. The first 10 "S + 1" slots are each composed of a mini-slot for RTS messages, [MS1, MF, SIG] and a mini-slot for CTS messages, [MS2, MF, SIG]. The last slot (S + 2) contains a first mini-slot [MS1 (S + 2), MF, SIG] for partial acknowledgment messages P-ACK and a second mini-slot [MS2 (S + 2), SIG] neutralized (not used) [MSn, MF (M + 1)].
[0011] The last MF + 1 mini-frame exactly takes the form of the frame of the GIS channel (FIG. 4A) with the exception of the last slot which contains only one deactivated minislot. On the DATA channel, the first "M" mini-frames are each composed of "S + 2" slots. The first "S + 1" slots are for DATA data messages while the last slot of a mini-frame is composed of a deactivated mini-slot MSn (S + 2) and a mini-slot MSa (S + 2) for ACK messages. The last MF + 1 mini-frame takes exactly the form of the frame of the DATA channel, FIG. 4A, with the exception of the last slot which contains only a mini-slot for the ACK messages, MSa (MF + 1). A data transmission can now take place on one or more mini-frames but must terminate at the end of one of the mini-frames of the frame where the data transmission has started. The method using this type of frame will include, for example, the steps described hereinafter. Phase A A node that is not transmitting or receiving on the DATA channel listens continuously to the GIS signaling channel (RTS, CTS, P-ACK) 3031271 19 A.1. If it detects a broadcast on a mini-slot CTS (second slot mini-slot) of one of the "S" first slots, then it prohibits all access to mini-slots RTS (first mini-slot slot) from the GIS channel to the end of the current mini-frame, it thus becomes a node blocked in transmission on the current mini-frame MFc. A.2. If it detects a transmission on the mini-slot CTS of the slot "S + 1", [MS2 (S + 1), MFc, SIG] then it is prohibited any access to the mini-slots RTS of the channel GIS the end of the next mini-frame, it thus becomes a blocked node in transmission on the following mini-frame MFs, A.3. If it detects a transmission on the mini-slot P-ACK of the slot "S + 2", [MS2 (S + 2), MFc, SIG] then it prohibits any access to the mini-slots RTS of the channel GIS until at the end of the next mini-frame, it thus becomes a blocked node in transmission on the next mini-frame MFs. The mini-slot P-ACK is not present on the last mini-frame M + 1 of the frame.
[0012] A.4. If it detects a transmission on a mini-slot RTS (first mini slot of the slot) of one of the "S" first slots, [MS1 (s), MFc, SIG] then it prohibits any access to mini-slot CTS slot (second slot mini slot) of the GIS signaling channel until the end of the current mini-frame, it becomes a node blocked in reception on the current MFc mini-frame.
[0013] A.5. If it detects a transmission on the mini-slot RTS of the slot "S + 1", [MS1 (S + 1), MFc, SIG] then it prohibits any access to the mini-slots CTS of the channel GIS the end of the next mini-frame, it thus becomes a node blocked in reception on the following mini-frame MFs. Phase B A 10th node desiring to transmit draws a random number and initiates a countdown, K, with the value of the drawn number, B.1. The counter K is decremented at each slot if the node does not detect transmission on the slot's mini-slot CTS, B.2. The counter K is blocked until the end of the reception if the node 10e correctly decodes an RTS message intended for it. The end of the reception is indicated in the RTS message 3031271 B.3. On the "S" first slots of the mini-frame, the counter K is blocked until the end of the current mini-frame MFc if the node 10e detects a transmission on the slot mini-slot CTS, B.4. On the slot "S + 1" of the current mini-frame MFc, the counter K is blocked 5 until the end of the following mini-frame MFs = MF (c + 1) if the node detects a transmission on the mini -slot CTS slot, [MS2 (S + 1), MFc, SIG], B.5. On the slot "S + 2" of the current mini-frame MFc, the counter K is blocked until the end of the following mini-frame MFs = MF (c + 1) if the node detects a transmission on the mini-frame P-ACK slot slot, [MS2 (S + 1), MFc, SIG].
[0014] The mini-slot P-ACK is not present on the last mini-frame M + 1 of the frame. B.6. The counter K is blocked during the slot "S + 2" of each mini-frame MF. Phase C When the counter K expires, the node 10e sends a message of the RTS type to notify its desire to transmit to the recipient. This broadcast takes place on the GIS channel, C.1. On the first mini-slot of the slot following expiration if the counter K expires in the "S" first slots of the MFc mini-frame, 20 C.2. On the first mini-slot of the first slot of the next mini-frame MF (c + 1) if the counter K expires at the slot "S + 1" of the current mini-frame MFc. Phase D If the destination terminal 10r correctly receives the request message to be transmitted RTS and if it is not blocked in reception, then the destination node 10r responds by sending a message of the type CTS to indicate to the node transmitter that it is available for reception. The transmission of the CTS message takes place on the second mini-slot (slot CTS) of the slot where the transmission of the RTS message, Phase E 3031271 21 E.1 took place. If the sending terminal 10e of the RTS correctly receives the message CTS, then the transmission of the data begins, on the DATA channel, to the next slot if the successful exchange RTS / CTS took place in one of the "S" first slots of the mini current frame MFc, or the first slot of the next mini-frame MFs if the RTS / CTS exchange took place at slot "S + 1" of the current mini-frame MFc. Thus, the communication can start at any slot of the frame Fc or Fs at the expiry of the counter K and after a successful RTS / CTS exchange, and can extend over several mini-MF frames, but necessarily ends at the end of one of the mini-frames of the frame Fc 10 or Fs where the data transmission started. The transmitting node 10e indicates the last mini-frame of the data transmission in its RTS message, E.2. If the transmitting terminal 10e does not correctly receive the CTS message, then it will either be able to abort the current data transmission or try to access the channel again by again following steps C through E until it receives correctly. the CTS message. If the sending node fails to receive the CTS message after a predefined number of attempts, then it abandons the current transmission of the data. Phase F A recipient node 10r or receiver sends an ACK message on the DATA channel at the end of the last transmission mini-frame and a PACK message on the signaling channel at the end of each of the other intermediate mini-frames of the transmission. Figure 5A schematizes a variant for a signaling channel and a separate data channel with a validation step of the RTS. The TDMA frame of the variant of FIG. 4A of the protocol is taken again and the frame is modified on the signaling channel in such a way that each slot of the first "S + 1" slots is now composed of three mini-slots: a first mini-siot MS1 for sending RTS messages, a second 30 mini-slot MS2 for sending CTS messages, and a third mini-slot MS3 for sending messages type confirmation of access to 3031271 22 channel or CAC (Channel Access Confirmed). A CAC-type message is sent by a node that has passed a RTS / CTS exchange to inform its neighborhood that it has received a positive response to its RTS message and that it will therefore effectively access the DATA channel.
[0015] The steps of the method implementing such a type of frame will then be as follows. Phase A A node that is not transmitting or receiving on the DATA channel is listening to the GIS channel, A.1. If it detects a transmission on a mini-slot CTS (second slot mini-slot) of one of the "S" first slots, [MS2, SIG] then it prohibits all access to mini-slots RTS (first mini -slot of the slot [MS1, SIG]) of the SIG channel until the end of the current frame, it thus becomes a node blocked in transmission on the current frame Fc.
[0016] A.2. If it detects a transmission on the mini-slot CTS of the slot "S + 1", [MS2 (S + 1), SIG]) then it prohibits any access to the mini-slots RTS of the channel of SIG until the end of the next frame, it becomes a node blocked in transmission on the next frame Fs, A.3. If it detects a transmission on the mini-slot CAC (third slot mini-slot) of one of the "S" first slots, [MS3, SIG]) then it prohibits any access to the mini-slots CTS of GIS channel until the end of the current frame, it thus becomes a node blocked in reception on the current frame Fc, A.4. If it detects a transmission on the mini-slot CAC (third mini-slot of the slot) of the slot "S + 1", then it prohibits all access to the mini-slots CTS of the channel 25 SIG until the end of the next frame, it thus becomes a node blocked in reception on the following frame Fs. Phase B A 10e node desiring to transmit draws a random number and initiates a countdown K with the value of the drawn number, B.1. The counter K is decremented at each slot if the node 10e does not detect transmission on the mini-slot CTS of the slot, 3031271 23 B.2. The counter K is blocked until the end of the frame if the node correctly decodes an RTS message intended for it, B.3. On the "S" first slots of the frame, the counter K is blocked until the end of the current frame Fc if the node 10e detects a transmission 5 on the slot mini-slot CTS, MS2 (s), B. 4. On the slot "S + 1" of the frame Fc, the counter K is blocked until the end of the next frame Fs, if the node 10e detects a transmission on the minislot CTS of the slot, B.5. The counter K is blocked during the slot "S + 2", Phase C At the expiry of the counter K the node 10e sends a message of the RTS type to notify its desire to transmit to the receiver 10r. This broadcast takes place on the GIS channel, C.1. On the first mini slot of the slot following expiration if the counter K 15 expires in the "S" first slots of the frame, C.2. On the first mini-slot of the first slot of the next frame Fs if the counter K expires at the slot "S + 1" of the current frame Fc. Phase D If the receiving terminal 10r correctly receives the request message to be transmitted RTS and if it is not blocked in reception, then the destination node responds by sending a message of the type CTS to indicate to the sending node that it is available for reception. The transmission of the CTS message takes place on the mini slot CTS of the slot where the transmission of the message RTS, MS2 (s, RTS) took place.
[0017] 25 Phase E E.1. If the sending terminal 10e of the RTS correctly receives the CTS message then it sends a CAC type message on the SIG channel on the third mini-slot of the slot where has the exchange RTS / CTS, MS3 (s, RTS / CTS) . The data transmission starts, on the DATA channel, at the next slot if the successful RTS / CTS exchange has taken place in one of the first "S" slots of the frame, or the first slot of the next frame Fs if the RTS / CTS exchange took place at slot "S + 1" of the current frame Fc. Thus, the communication can start at any slot of the frame at the expiration of the counter and after a successful RTS / CTS exchange, but it necessarily ends at the end of the frame where the data transmission started just before the last 5 slot, E.2. If the transmitting terminal 10e does not correctly receive the CTS message then it will be able to either abandon the current transmission of the data, or try again to access the channel by again following the steps of the phases C to E until receiving the message correctly. CTS. If the sending node 10e fails to receive the CTS message after a predefined number of attempts then it abandons the current transmission of the data. Phase F A receiver node 10r sends on the DATA channel on the last slot of the frame a message of the ACK type to inform the transmitter of the reception state of the DATA. FIG. 5B schematizes a variant of FIG. 5A in the multi-frame case with M + 1 (M> = 0) mini-frames. The TDMA frame of the variant described in FIG. 4B of the protocol is resumed and the frame is modified on the signaling channel so that each slot of the first "S + 1" slots 20 of each mini-frame is now composed of three mini-slots: a first mini-slot MS1 for sending RTS messages, a second mini-slot MS2 for sending CTS messages, and a third mini-slot MS3 for sending a message type CAC. The last slot S + 2 of the first M frames on the GIS channel is modified to contain three mini-slots: the first 25 MS1 (S + 2) for sending messages of P-CAC type (Persistent CAC), the second MS2 (S + 2) for sending messages of type P-ACK, and a third MS3 (S + 2) mini-siot not used. The P-CAC message allows a transmitting node that has gained access to the data channel DATA on several mini-frames to inform its neighborhood at the end of each mini-frame that it would continue its data transmission on the DATA channel 3031271 during the next mini-frame. This message is therefore not sent at the end of the last mini-frame of data transmission. The last slot S + 2 of the first M mini-frames on the data channel DATA is modified to contain three mini-slots: the first two mini-slots [MS1, MS2, DATA] are not used, and the third mini -slot [MS3, DATA] is reserved for sending ACK messages. The method using this type of frame will comprise for example the steps described below. Phase A A node that is not transmitting or receiving on the DATA channel is listening to the GIS channel, A.1. If it detects a broadcast on a mini-slot CTS (second slot mini-slot) of one of the "S" first slots, then it prohibits all access to mini-slots RTS (first mini-slot slot) from the SIG signaling channel to the end of the current mini-frame, it thus becomes a blocked node in transmission on the current mini-frame, A.2. If it detects a transmission on the mini-slot CTS slot "S + 1", then it prohibits all access to the mini-slots RTS signaling channel GIS until the end of the next mini-frame, it thus becomes a node blocked in transmission on the next mini-frame, A.3. If it detects a broadcast on the mini-slot P-ACK slot "S + 2", then it prohibits all access to mini-slots RTS signaling channel GIS until the end of the next mini-frame , it thus becomes a blocked node in transmission on the next mini-frame, A.4. If it detects a transmission on the mini-slot CAC (third mini-slot of the slot) of one of the "S" first slots, then it prohibits all access to the mini-slots CTS of the channel GIS until the end of the current mini-frame, it thus becomes a node blocked in reception on the current frame, A.5. If it detects a transmission on the mini-slot CAC (third mini-slot of the slot) of the slot "S + 1", then it prohibits any access to the mini-slots CTS of the channel 3031271 26 signaling the end of the next mini-frame, it thus becomes a node blocked in reception on the next mini-frame, A.6. If it detects a transmission on the mini-slot P-CAC of the slot "S + 2", then it prohibits all access to the mini-slots CTS of the signaling channel GIS until the end of the mini-frame next, it thus becomes a node blocked in reception on the next mini-frame, Phase B A node wishing to send 10e draws a random number and initiates a countdown K with the value of the number drawn, 10 B.1. The counter K is decremented at each slot if the node 10e does not detect a transmission on the slot mini-slot CTS, B.2. The counter K is blocked until the end of the reception if the node 10e correctly decodes an RTS message intended for it. The end of the reception is indicated in the RTS message, B.3. On the "S" first slots of the mini-frame, the counter K is blocked until the end of the current mini-frame MFc if the node 10e detects a transmission on the slot mini-slot CTS, B.4. On the slot "S + 1" of the mini-frame MFc, the counter K is blocked until the end of the next mini-frame MFs if the node detects a transmission 20 on the slot mini-slot CTS, B. 5. On the slot "S + 2" of the mini-frame MFc, the counter K is blocked until the end of the following mini-frame MFs if the node detects a transmission on the mini-slot P-ACK slot, B .6. The counter K is blocked during the slot "S + 2" of each mini-frame 25 MF of the frame, CA phase the expiration of the counter K the node 10e sends a message of the RTS type to notify its wish to transmit to the recipient . This broadcast takes place on the GIS channel, 30 C.1. On the first mini-slot of the slot following expiration if the counter K expires in the "S" first slots of the mini-frame, 3031271 27 C.2. On the first mini-slot of the first slot of the next mini-frame if the counter expires at the slot "S + 1" of the current mini-frame, Phase D If the receiving terminal correctly receives the request message to be sent RTS and if it is not blocked on reception, then the destination node responds by sending a message of the CTS type to indicate to the sending node that it is available for reception. The transmission of the CTS message takes place on the second mini-slot (slot CTS) of the slot where the transmission of the RTS message, 'Io Phase E E.1 took place. If the transmitting terminal 10e of the RTS correctly receives the CTS message, then it sends a CAC type message on the SIG signaling channel on the third mini-slot of the slot where the RTS / CTS exchange took place. The data transmission starts, on the DATA channel, at the next slot if the successful RTS / CTS exchange took place in one of the first "S" slots of the mini-frame, or the first slot of the next mini-frame. if the RTS / CTS exchange took place at slot "S + 1" of the current mini-frame. Thus, the communication can start at any slot of the frame at the expiration of the counter and after a successful RTS / CTS exchange, and can span several mini-frames but must end at the end of the frame. one of the mini-frames of the frame where the data transmission started. The transmitting node indicates the last mini-frame of the data transmission in its RTS message. E.2. If the transmitting terminal does not correctly receive the CTS message 25 then it will be able to either abandon the current transmission of the data or try again to access the channel by again following the steps of the phases C to E until receiving the message CTS correctly. . If the sending node fails to receive the CTS message after a predefined number of attempts then it abandons the current transmission of the data.
[0018] The transmitting node sends a P-CAC message on the GIS channel on the first mini slot of the last slot S + 2 of each of the mini data frames except for the last mini-frame. data transmission.
[0019] 5 Phase G The receiving or receiving node sends an ACK message on the DATA channel at the end of the last data transmission mini-frame and a P-ACK message on the signaling channel on the second mini slot of the last S slot +2 of each of the other intermediate mini-frames of the data transmission. FIG. 6A schematizes the structure of a frame in the case of transmission over Ns signaling channels and over Nd data channels. It is now considered that the TDMA frame of the protocol version described in FIG. 4A is supported by "Ns + Nd" separate radio channels (frequency, code, etc.): "Ns" GIS and "Nd" channels "DATA channels where" Nd "is multiple of" Ns ":" Nd = P * Ns ". It is assumed that the nodes 10n are able to receive simultaneously on the "Ns" GIS channels. On GIS channels, the frame contains "S + 1" macro-signaling slots RTS / CTS, [GS, SIG] and a last unused slot Sn (S + 2). Each of the 20 signaling macro-slots [GS, SIG] is composed of "P" slots, and each slot is itself composed of two mini-slots RTSn, i, CTS ,,,; with n the channel number and i the slot number in a GS macro-slot. The first mini-slot RTS 'carries messages of the RTS type and the second minislot CTS' carries messages of the CTS type. The "i" th slot of each 25 GS macro-slot on the "n" th GIS signaling channel is used for RTS / CTS reservation signaling exchange to access the "d" th data channel such as "d". = (n-1) * P + i ". On the DATA data channels, the frame contains "S + 1" macro-data slots and a last ACK S (ACK) acknowledgment slot. Each of the data macro-slots or DATA 30 is itself composed of "P" data slots DATA.
[0020] By using this frame structure, the method comprises the steps described hereinafter. Phase A A node that is not transmitting or receiving on a DATA channel 5 is listening to the GIS channels, A.1. If it detects a transmission on the channel GIS "n" on the mini-slot CTS of the "i" th slot CTSn, i of one of the "S" first macro-slots of the frame Fc then it is prohibited any access at the mini-slots RTS of the "i" th slot of the macro-slots on this signaling channel "n" until the end of the current frame, it thus becomes a node blocked in transmission to the DATA channel "d = (n -1) P + i "corresponding to this signaling channel" n "and to this slot" i "until the end of the current frame, A.2. If it detects a transmission on the SIG channel "n" on the mini-slot CTS of the "i" th slot of the macro-slot "S + 1" [CTSn, i, GS (S + 1)] of the frame Fc , then it forbids any access to the mini-slots RTS of the "i" th slot of the macro-slots [RTS ,,,;, GS (s)] on this signaling channel "n" until the end of the following frame Fs, it thus becomes a blocked node in transmission on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and this slot "i" until the end of the next frame.
[0021] A.3. If it detects a transmission on the SIG channel "n" on the mini-slot RTS [RTS ,,,;, GS (s)] of the "i" th slot of one of the "S" first macro-slots of the frame then it prohibits all access to the mini-slots CTS of the "i" th slot of the GS (s) macro-slots on this signaling channel "n" until the end of the current frame, it becomes a node blocked in reception on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and to this slot "i" until the end of the current frame, A.4 . If it detects a transmission on the SIG channel "n" on the mini-slot RTS of the "i" th slot of the macro-slot "S + 1" [RTS ,,,;, GS (S + 1)] of the frame Fc, then it prohibits all access to the mini-slots CTS of the "i" th slot of the macro-slots 30 [CTSn, i, GS (s)] on this signaling channel "n" until the end of the next frame, it thus becomes a node blocked in reception on the DATA channel 3031271 30 "d = (n-1) P + i" corresponding to this signaling channel "n" and to this slot "i" until the end of the next frame. Phase B A 10e node desiring to transmit draws a random number and initiates a countdown K with the value of the drawn number. The node 10e constantly listens to all the GIS signaling channels simultaneously. On each signaling channel "n", B.1. The counter K is decremented at each slot s of GS signaling macro-slots (S) if the node does not detect transmission on the slot 10 CTS mini-slot, B.2. On the "S" first macro-slots of the frame, the counter K is blocked and the node 10e is blocked in transmission on the signaling channel "n" and on the slot "i" of each macro-slot until the end of the current frame Fc if the node detects a transmission on the mini-slot CTS of slot "i".
[0022] The node is blocked in transmission on the corresponding DATA channel "d = (n1) P + i" until the end of the current frame, B.3. On the macro-slot "S + 1", GS (S + 1) the counter K is blocked and the node 10e is blocked in transmission on the signaling channel "n" and on the slot "i" of each macro-slot until the end of the next frame if the node 10e detects a transmission on the mini-slot CTS slot "i". The node 10e is blocked in transmission on the corresponding DATA channel "d = (n-1) P + i" until the end of the next frame, B.4. The counter K is blocked during the last slot of the frame Fc. Phase C When the counter K expires, the node 10e sends a message of the RTS type to notify its desire to transmit to the recipient 10r. This transmission occurs on the slot "i" and the signaling channel "n" corresponding to the DATA channel "d = (n-1) P + i" randomly chosen by the sending node 10e among the DATA channels on which it is not blocked in broadcast.
[0023] The emission takes place: 3031271 31 C.1. On the macro-slot following expiration if the counter expires in the "S" first macro-slots of the frame, C.2. On the first macro-slot of the next frame Fs if the counter expires at the macro-slot "S + 1" of the current frame Fc.
[0024] Phase D If the recipient 10r correctly receives the RTS message on the RTS slot ,,,; and if it is not blocked in reception on the DATA channel "d = (n-1) P + 1" corresponding to the slot "i" and the channel SIG "n" used for sending the RTS message, then he responds by sending a CTS message on the second 10 mini-slot CTS ,,,; of the slot "i" where the transmission of the RTS message took place and on the same SIG channel "n" where the transmission of the RTS took place to indicate to the sending node that it is available for reception. Phase E E.1. If the sending node 10e receives the CTS message correctly then the data transmission occurs on the DATA channel "d = (n-1) P + i" corresponding to the slot "i" and the signaling channel "n" used for the exchange of RTS / CTS messages. The data transmission starts at the next slot (s + 1) if the RTS / CTS exchange took place in one of the first "P-1" slots of the current GSc macro-slot, or the first slot of the 20-slot slot. next GSc + i if the RTS / CTS exchange took place at slot "P" of the current macro-slot GSc. The communication can begin at any slot s of the frame Fc or Fs at the expiry of the counter K and after a successful exchange RTS / CTS, but necessarily ends at the end of the frame Fc or Fs where the transmission of data started just before the acknowledgment slot, ACK, S (ACK). E.2. If the transmitting terminal 10e does not correctly receive the CTS message, then it will be able to either abandon the current transmission of the data, or try again to access the channel by again following the steps of the phases C to E until it is correctly received. CTS message. If the sending node 10e fails to receive the CTS message after a predefined number of attempts then it abandons the current transmission of the data.
[0025] A receiver node 10r sends on the DATA channel where its reception took place on the last slot of the frame, a message of the ACK type to inform the transmitter of the reception state of the DATA. FIG. 6B represents a frame variant similar to that of FIG. 6A in the case of MF multi-frames. It is now considered that the TDMA frame of the multi-frame FM version of the protocol is supported by "Ns + Nd" distinct radio channels (frequency, code, etc.): "Ns" SIG (signaling) and "Nd" channels »DATA channels, where" Nd "10 is multiple of" Nd ":" Nd = P * Ns ". It is assumed that the nodes 10n are able to receive simultaneously on the "Ns" GIS channels. On GIS channels, the frame is divided into "M + 1" (M> = 0) mini-frames. The first "M" mini-frames MFi are optional, the last MF mini-frame (M + 1) is mandatory and takes exactly the shape of the GIS frame of the variant of Figure 6.A. On GIS channels, each of the first "M" mini MF frames is composed of "S + 2" macro-slots GS: "S + 1" macro-signaling slots RTS / CTS GS (RTS / CTS) and a last signaling macroslot P-ACK, GS (P-ACK). Each of the "S + 1" signaling macro-slots RTS / CTS is composed of "P" slots, and each of the "P" slots 20 is itself composed of two mini-slots, MS1 = RTSnj, MS2 = CTS, ,, i with n the signaling channel number and i the number or position of the slot in a macro-slot. The first RTS mini-slot j carries RTS-type messages and the second mini-slot carries messages of the CTS type. The P-ACK GS signaling macro-slot (P-ACK ,,,;) is composed of "P" slots 25 which carry P-ACK type messages and a last slot unused Sn. The last MF mini-frame (M + 1) resumes the construction of the first "M" frames except for the last macro-slot which now contains only one unused slot [Sn, MF (M + 1)] . The "i" th slot of each GS macro-slot of each mini-MF frame on the "n" th SIG channel 30 is used for the RTS / CTS reservation signaling exchange to access the "th" DATA channel such as that "d = (n-1) * P + i". The "i" th slot of the last P-ACK macro-slot, GS (P-ACK ,,,;) of each mini-MF frame on the "n" th GIS channel is used to send message P -ACK corresponding to the DATA channel "d" such that "d = (n-1) * P + i". On the DATA channels, the frame also contains "M + 1" (M> = 0) mini MF frames. The first "min" frames are optional, the last mini-frame is mandatory and exactly takes the form of the DATA frame of the variant figure 6.A. On the DATA channels, each of the first "M" mini MF frames is composed of "S + 2" macro-slots: "S + 1" macro-slots of DATA and a last macro-signaling slot ACK. Each of the "S + 1" macro-slots of DATA is composed of P slots of data. The ACK macro-signaling slot is composed of "P" unused slots Sn and a last slot ACK to carry messages of type ACK. The last MF mini-frame (M + 1) takes the construction of the first "M" except the last macro-slot [GS (M + 1), ACK] which now contains only one ACK slot for 15 carry messages of type ACK. With this frame structure, the method comprises the following steps. Phase A A node that is not transmitting or receiving on a DATA channel 20 listens to the GIS channels, A.1. If it detects a broadcast on the signaling channel "n" on the minislot CTS CTS ,,,; of the "i" th slot of one of the "S" first macro-slots GS of the current MFc mini-frame then it is prohibited any access to the mini-slots RTS of the "i" th slot, RTS ,,,;, GS macro-slots on this signaling channel SIG 25 "n" until the end of the current mini-frame MFc, it thus becomes a node blocked in transmission to the DATA channel "d = (n-1) P + i Corresponding to this signaling channel "n" and this slot "i" until the end of the current mini-frame MFc, A.2. If it detects a transmission on the signaling channel "n" on the mini30 slot CTS of the "i" th slot of the macro-slot "S + 1" [CTSn, i GS (S + 1)] of the minitrame MFc, then it is prohibited any access to mini-slots RTS of the "i" th slot, 3031271 34 RTS ,,,; ' macro-slots on this signaling channel until the end of the following mini-frame MFs = MFc + i, it thus becomes a node blocked in transmission on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and at this slot "i" until the end of the next mini-frame, 5 A.3. If it detects a transmission on the signaling channel "n" on the slot P-ACK "i" of the macro-slot "S + 2", GS (S + 2)] of the mini-frame MFc, then it s 'forbids any access to the mini-slots RTS of the' i 'th slot, RTS, - ,,;' macro-slots on this signaling channel until the end of the next mini-frame MFs, it thus becomes a node blocked in transmission on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and at this slot "i" until the end of the next mini-frame, A.4. If it detects a broadcast on the signaling channel "n" on the RTS minislot of the "i" th slot of one of the "S" first macro-slots of the mini-frame, GS (s)] then it is prohibits access to the mini-slots CTS of the "i" th slot 15 macro-slots [CTSnj, GS (s)] on this signaling channel SIG until the end of the current mini-frame MFc, it becomes a node blocked in reception on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and to this slot "n" until the end of the current mini-frame MFc, 20 AT 5. If it detects a transmission on the signaling channel "n" on the mini-slot RTS of the "i" th slot of the macro-slot "S + 1" [RTS ,,,; , GS (S + 1)] of the MFc minitrame then it prohibits any access to the mini-slots CTS of the "i" th slot of the GS (s) macro-slots on this channel GIS until the end of the following mini-frame MFs, it thus becomes a node blocked in reception on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and to this slot "i" up to the end of the next mini-frame. Phase B A 10th node wishing to transmit draws a random number and initiates a countdown, K, with the value of the drawn number. The node continuously listens to all GIS channels simultaneously. On each signaling channel "n", 303 1 2 7 1 B.1. The counter K is decremented at each slot of the signaling macro-slots if the node 10e does not detect transmission on the slot mini-slot CTS, B.2. On the "S" first macro-slots GS of the mini-frame MFc, the counter K is blocked and the node 10e is blocked in transmission on the signaling channel "n" and on the slot "i" until the end of the current MFc mini-frame if the node detects a transmission on the mini-slot CTS slot "i". The node 10e is blocked in transmission on the DATA channel "d = (n-1) P + i" corresponding to the end of the current mini-frame MFc, B.3. On the macro-slot "S + 1", the counter K is blocked and the node 10e is blocked in transmission on the signaling channel "n" and on the slot "i" until the end of the next mini-frame if the node 10e detects a transmission on the mini-slot CTS slot "i". The node 10e is blocked in transmission on the corresponding DATA channel "d = (n-1) P + i" until the end of the next mini-frame MFs, B.4. On the macro-slot "S + 2", the counter K is blocked and the node 10e is blocked in transmission on the signaling channel "n" and on the slot "i" until the end of the next mini-frame if the node 10e detects a transmission on the slot P-ACK "i". The node 10e is blocked in transmission on the corresponding DATA channel "d = (n-1) P + i" until the end of the next mini-frame MFs, B.5. The counter K is blocked during the last slot of each frame F. Phase C When the counter K expires, the node 10e sends a message of the RTS type 25 to notify its desire to transmit to the recipient. This transmission occurs on the slot "i" and the signaling channel "n" corresponding to the DATA channel "d = (n-1) P + i" randomly chosen by the transmitting node among the DATA channels on which it is not not blocked in issue. The show takes place, C.1. On the macro-slot following expiration if the counter K expires in the first 30 "S" macro-slots of the mini-frame, 3031271 36 C.2. On the first macro-slot of the next mini-frame if the counter K expires at the macro-slot "S + 1" of the current mini-frame. Phase D If the recipient 10r correctly receives the RTS message on the RTS slot ,,,; 5 and if it is not blocked in reception on the DATA channel "d = (n-1) P + i" corresponding to the slot "i" and the channel SIG "n" used to send the RTS message, then he answers by return of a message CTS on the second mini-slot CTS ,,,; of the slot where the transmission of the RTS message took place and on the same SIG channel where the transmission of the RTS took place to indicate to the sending node that it is available for reception. Phase E E.1. If the sending node 10e correctly receives the message CTS, then the transmission of DATA occurs on the DATA channel "d = (n-1) P + i" corresponding to the slot "i" and the signaling channel GIS "n" used for the exchange of RTS / CTS messages. The transmission of the data begins, E.1.a At the next slot if the RTS / CTS exchange took place in a slot of the "S" first macro-slots of the current mini-frame MFc, E.1.b At the slot next if the RTS / CTS exchange took place in one of the "P-1" 20 slots of the macro-slot "S + 1" of the current mini-frame MFc, E.1.c In the first slot of the first macro- slot of the following mini-frame MFs if the RTS / CTS exchange took place at slot "P" of the macro-slot "S + 1" of the current MFc minitrame. Thus, the communication can begin at any slot of the frame at the expiration of the counter K and after a successful RTS / CTS exchange, and can span several mini-frames, but must end at the end. of one of the mini-frames of the frame where the data transmission started. The transmitting node indicates the last mini-frame of the DATA data transmission in its RTS message.
[0026] E.1.f. If the transmitting terminal 10e does not correctly receive the CTS message then it will be able to either abandon the current transmission of the data, or try again to access the channel by again following the steps C to E until it is correctly received. CTS message. If the transmitting node fails to receive the CTS message after a predefined number of attempts then it abandons the current transmission of data, 5 Phase F The receiving node 10r sends an acknowledgment message ACK on the DATA channel used for transmitting the data to the end of the last transmission mini-frame, and a P-ACK message on the GIS channel "n" and on the P-ACK slot "i", corresponding to the DATA channel "d = (n-10 1) P + i "used for data transmission, used at the end of each of the other mini-frames intermediate transmission. Figure 7A shows a frame structure for `Ns 'separate GIS channels and` Nd' channels with RTS validation. The TDMA frame of FIG. 6.A of the protocol is taken again and the frame is modified on the SIG signaling channels such that each slot of the GS macro-slots is now composed of three mini-slots: a first mini-slot MS1 for sending RTS messages, a second mini-slot MS2 for sending CTS messages, and a third mini-slot MS3 for sending a message type CAC.
[0027] Phase A A node that is not transmitting or receiving on a DATA channel listens to the GIS channels, A.1. If it detects a transmission on the channel GIS "n" on the mini-slot CTS of the "i" th slot of one of the "S" first macro-slots of the frame Fc, [CTS ,,,;, GS] 25 then it prohibits any access to the mini-slots RTS [RTS ,,,;, GS] of the "i" th slot of the macro-slots on this signaling channel SIG "n" until the end of the current frame Fc, it thus becomes a node blocked in transmission to the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and to this slot "i" until the end of the current frame Fc, 30 A.2. If it detects a transmission on the SIG channel "n" on the mini-slot CTS of the "i" th slot of the macro-slot "S + 1" [CTS ,,,;, GS (S + 1)] of the frame Fc, then it 303 12 71 38 prohibits all access to the mini-slots RTS of the "i" th slot of the macro-slots on this signaling channel "n" until the end of the next frame Fs, it becomes and a node blocked in transmission on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and to this slot "i" until the end of the next frame, A .3. If it detects a transmission on the channel GIS "n" on the mini-slot CAC of the "i" th slot of one of the "S" first macro-slots, [CAC, GS (S)] of the frame Fc then it is forbidden any access to the mini-slots CTS of the "i" th slot of the macroslots [CTS ,,,;, GS (S)] on this channel SIG "n" until the end of the current frame 10 Fc it thus becomes a node blocked in reception on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and to this slot "i" until the end of the current frame Fc, A.4. If it detects a transmission on the SIG channel "n" on the mini-slot CAC of the "i" th slot of the macro-slot "S + 1" [CAC ,,,;, GS (S + 1)] of the Fc frame then it 15 prohibits all access to the mini-slots CTS of the "i" th slot of the macro-slots [CTS, - ,, i, GS (S)] on this channel GIS "n" until the end of the next frame, it thus becomes a node blocked in reception on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and to this slot "i" until the end of the next frame.
[0028] Phase B A node desiring to transmit draws a random number K and initiates a countdown with the value of the drawn number. The node constantly listens to all GIS signaling channels simultaneously. On each signaling channel "n", 25 B.1. The counter K is decremented at each slot of the signaling macro-slots GS if the node 10e does not detect transmission on the slot mini-slot CTS, B.2. On the "S" first macro-slots of the frame Fc, the counter K is blocked and the node 10e is blocked in transmission on the signaling channel 30 SIG "n" and on the slot "i" until the end of the current frame Fc if the node 10e detects a transmission on the mini-slot CTS slot "i". The node is blocked in transmission on the corresponding DATA channel "d = (n-1) P + i" until the end of the current frame, B.3. On the macro-slot "S + 1", the counter K is blocked and the node 10e is blocked in transmission on the signaling channel "n" and on the slot "i" 5 until the end of the next frame Fs if the node 10e detects a transmission on the mini-slot CTS slot "i". The node 10e is blocked in transmission on the DATA channel "d = (n-1) P + i" corresponding to the end of the next frame Fs, B.4. The counter K is blocked during the last slot of the frame Fc.
[0029] Phase C When the counter K expires, the node 10e sends a message of the RTS type to notify its desire to transmit to the recipient. This transmission occurs on the slot "i" and the signaling channel "n" corresponding to the DATA channel "d = (n-1) P + i" randomly chosen by the transmitting node among the 15 DATA channels on which it is not blocked in broadcast. The show takes place, C.1. On the macro-slot following expiration if the counter expires in the "S" first macro-slots of the frame, C.2. On the first macro-slot of the next frame if the counter expires at the macro-slot "S + 1" of the frame.
[0030] Phase D If the recipient 10r correctly receives the RTS message and is not blocked on reception on the DATA channel "d = (n-1) P + i" corresponding to slot "i" and to the GIS channel " n "used for sending the RTS message, then it responds by sending a CTS message on the second mini-slot CTS ,,,; of the slot where the transmission of the RTS message took place and on the same SIG channel "n" where the transmission of the RTS took place to indicate to the sending node that it is available for reception. Phase E E.1. If the transmitting node 10e correctly receives the CTS message then it sends a CAC type message to the third CAC ,,, mini-slot; of the slot where had the exchange RTS / CTS. The transmission of DATA occurs on the channel 3031271 DATA "d = (n-1) P + i" corresponding to the slot and the signaling channel used for the exchange of RTS / CTS messages. The data transmission starts at the next slot if the RTS / CTS exchange took place in one of the first "P1" slots of the current macro-slot, or the first slot of the next macro-slot 5 if the RTS / CTS exchange has occurred at the "P" slot of the current GSc macro-slot. The communication can begin at any slot of the frame at the expiration of the counter and after a successful RTS / CTS exchange, but ends obligatorily at the end of the frame where DATA transmission started just before the ACK slot , E.2. If the transmitting terminal does not receive the CTS message correctly then it will either be able to abort the current transmission of the data or try to access the channel again by again following the steps of the phases C to E until the CTS message is correctly received. If the sending node fails to receive the CTS message after a predefined number of 15 attempts, then it abandons the current transmission of data. Phase F A receiving node sends on the DATA channel where its reception on the last slot of the frame a message of the ACK type to inform the transmitter of the state of reception of the data, FIG. 7B, is a variant multi-frame frame structure of FIG. 7A. The TDMA frame of variant 6.B of the protocol is resumed and the frame is modified on the GIS channels so that each slot of the first "S + 1" macro-slots of each mini-frame is now composed of three mini-slots: a first mini-slot for sending 25 RTS messages, a second mini-slot for sending CTS messages, and a third mini-slot for sending a message type CAC. The last S + 2 macro-slot of the first M mini-frames on the GIS channels is now composed of 2P + 1 slots: P slots P-CAC, P slots P-ACK, and a last slot not used. The last S + 2 macro-slot of the first M mini30 frames on the DATA channels is modified to contain 2P + 1 slots: 2P unused slots and a last ACK slot.
[0031] 3031271 41 Phase A A node that is not transmitting or receiving on a DATA channel listens to the SIG signaling channels A.1. If it detects a transmission on the SIG channel "n" on the mini-slot CTS of the 5th "i" th slot of one of the "S" first macro-slots of the current mini-frame then it is prohibited any access to the mini-slots RTS of the "i" th slot of the macroslots on this signaling channel until the end of the current mini-frame, it thus becomes a node blocked in transmission to the DATA channel "d = (n1) P + i Corresponding to this signaling channel "n" and this slot "i" 10 until the end of the current mini-frame, A.2.If it detects a transmission on the channel GIS "n" on the mini -slot CTS of the "i" th slot of the macro-slot "S + 1" of the current mini-frame then it is prohibited any access to the mini-slots RTS of the "i" th slot of the macro-slots on this channel of signaling until the end of the next mini-frame, it thus becomes a node blocked in transmission on the DATA channel "d = (n-1) P + i" corresponding to this signaling channel "n" and at this point slot "i" until the end of the mini-frame A.3.If it detects a transmission on the signaling channel "n" on the slot PACK "i" of the macro-slot "S + 2" of the current mini-frame then it prohibits 20 any access to the mini-slots RTS of the "i" th slot of the macro-slots on this signaling channel until the end of the next mini-frame, it thus becomes a node blocked in transmission on the DATA channel "d = (n- 1) P + i "corresponding to this signaling channel" n "and to this slot" i "until the end of the next mini-frame, A.4. If it detects a transmission on the channel SIG "n" on the mini-slot CAC of the "i" th slot of one of the "S" first macro-slots of the current mini-frame then it is prohibited any access to the CTS mini-slots of the "i" th slot of the macroslots on this signaling channel until the end of the current mini-frame, it thus becomes a node blocked in reception on the DATA channel "d = (n-1) P -Fi "corresponding to this signaling channel" n "and this slot" i "until the end of the current mini-frame.
[0032] 3031271 42 A.5. If it detects a transmission on the SIG channel "n" on the mini-slot CAC of the "i" th slot of the macro-slot "S + 1" of the current mini-frame, then it is forbidden any access to the mini-frames. CTS slots of the "i" th slot of the macro-slots on this signaling channel until the end of the next mini-frame, it thus becomes a node 5 blocked in reception on the DATA channel "d = (n-1) P + i "corresponding to this signaling channel" n "and this slot" i "until the end of the next mini-frame. A.6. If it detects a transmission on the channel GIS "n" on the slot P-CAC "i" of the macro-slot "S + 2" of the current mini-frame then it prohibits any access to the mini-slots CTS from the "i" th slot of the macro-slots on this signaling channel until the end of the next mini-frame, it thus becomes a node blocked in reception on the DATA channel "d = (n-1) P + i Corresponding to this signaling channel "n" and this slot "i" until the end of the next mini-frame.
[0033] Phase B A node desiring to transmit draws a random number and initiates a countdown K with the value of the drawn number. The node constantly listens to all GIS channels simultaneously. On each signaling channel "n", 20 B.1. The counter K is decremented at each slot of the signaling macro-slots if the node does not detect transmission on the slot's mini-slot CTS, B.2. On the "S" first macro-slots of the mini-frame, the counter is blocked and the node is blocked in transmission on the signaling channel "n" 25 and on the slot "i" until the end of the frame current if the node detects a transmission on the mini-slot CTS slot "i". The node is blocked in transmission on the corresponding DATA channel "d = (n-1) P + i" until the end of the current frame, B.3. On the macro-slot "S + 1", the counter is blocked and the node is blocked in transmission on the signaling channel "n" and on the slot "i" until the end of the next mini-frame if the node detects a transmission on the mini-slot 3031271 43 CTS slot "i". The node is blocked in transmission on the DATA channel "d = (n1) P + i" corresponding to the end of the next mini-frame, B.4. On the macro-slot "S + 2", the counter is blocked and the node is blocked in transmission on the signaling channel "n" and on the slot "i" until the end 5 of the next mini-frame if the node detects a transmission on the P-ACK slot "i". The node is blocked in transmission on the DATA channel "d = (n-1) P + i" corresponding to the end of the next mini-frame, B.5. The counter is blocked during the last slot of each frame. Phase C 10 At the expiry of the counter K the node sends a message of the RTS type to notify its desire to transmit to the recipient. This transmission occurs on the slot "i" and the signaling channel "n" corresponding to the DATA channel "d = (n-1) P + i" randomly chosen by the transmitting node among the DATA channels on which it is not not blocked in issue. The show takes place, 15 C.1. On the macro-slot following expiration if the counter expires in the "S" first macro-slots of the mini-frame, C.2. On the first macro-slot of the next mini-frame if the counter expires at the macro-slot "S + 1" of the mini-frame. Phase D 20 If the recipient correctly receives the RTS message and is not blocked on reception on the DATA channel "d = (n-1) P + i" corresponding to the slot "i" and the channel SIG "n Used to send the RTS message, then it responds by sending a CTS message on the second CTS mini-slot ,,,; of the slot "i" where the transmission of the RTS message took place and on the same SIG channel "n" where the transmission of the RTS took place to indicate to the sending node that it is available for reception. Phase E E.1. If the sending node correctly receives the CTS message then it sends a CAC message on the third CACn mini slot of slot "i" where RTS / CTS has been exchanged. DATA transmission occurs on the DATA channel "d = (n-1) P + i" corresponding to the slot "i" and the signaling channel 3031271 44 "n" used for the exchange of RTS / CTS messages. Data transmission begins, E.1.a. At the next slot if the RTS / CTS exchange took place in a slot of the "S" first macro-slots of the mini-frame, 5 E.1.b. At the next slot if the RTS / CTS exchange took place in one of the "P-1" slots of the "S + 1" macro-slot of the mini-frame, E.1.c. At the first slot of the first macro-slot of the next mini-frame if the RTS / CTS exchange took place at slot "P" of the macro-slot "S + 1" of the minitrame.
[0034] Thus, the communication can start at any slot of the frame at the expiration of the counter and after a successful RTS / CTS exchange, and can span several mini-frames, but must end at the end of the frame. one of the mini-frames of the frame where the data transmission started. The transmitting node indicates the last mini-frame of the DATA transmission in its RTS message. E.2. If the transmitting terminal does not receive the CTS message correctly then it will either be able to abort the current transmission of the data or try to access the channel again by again following the steps of the phases C to E until the CTS message is correctly received. If the sending node fails to receive the CTS message after a predefined number of attempts then it abandons the current transmission of the data. Phase F The transmitting node sends a P-CAC message on the SIG channel "n" and on the P-CAC slot "i" of the last slot S + 2 of each of the mini-frames of 25 data transmission with the exception of the last mini-frame of data transmission. The SIG channel "n" and the slot "i" correspond to the DATA channel "d = (n-1) P + i" used for the transmission of the data. Phase G The receiving node 10r sends an acknowledgment message ACK on the DATA channel used for data transmission at the end of the last transmission frame, and a P-ACK message on the GIS channel "n" and on 3031271 the P-ACK slot "i" corresponding to the DATA channel "d = (n-1) P + i" used for the data transmission used at the end of each of the other intermediate frames of the transmission.
[0035] References [1] G. Bianchi, "Performance Analytics of the EIET 802.11 distributed coordination function," IEEE Journal on Selected Area in Communications, vol. 18, 2000 [2] H. Anouar, C. Bonnet, 'Optimal Constant-Window Backoff Scheme for 10 IEEE 802.11 DCF in General Load Single-Hop Wireless Networks', 9-th ACM / IEEE International Symposium on Modeling, Analysis and Simulation of Wireless and Mobile Systems MSWIM 2006.

权利要求:
Claims (20)
[0001]
CLAIMS1 - Method for accessing a radio channel in a communication system 5 comprising a plurality of terminals (10n) communicating with each other by radio links, a terminal (10n) being equipped with transmission and / or reception means (11n, 12n), a processor (13n) adapted to perform the steps of the method, characterized in that it uses an access protocol based on a communication frame (F) composed of several slots S (1), S ( S + 2), the first 10 S slots each comprising two mini-slots, the first mini-slot MS1 comprising an RTS data transmission request signaling message or data, the second mini-slot MS2 including a message of signaling of "ready to receive", CTS, or data, the slot (S + 1) containing a message of the RTS type or data, the slot (S + 2) containing a message of the type CTS and a message of acknowledgment placed at the end of the frame in order to acknowledge one or more transmissions taking place on the e radio channel.
[0002]
2 - Method for accessing a radio channel according to claim 1, characterized in that a frame F is divided into (M + 1) mini-MF frames, each MF mini-frame having the structure of the frame of the claim 1 and for the first M mini-frames the first mini-slot MS1 of the slot (S + 2) contains a message CTS or a partial acknowledgment message P-ACK. 25
[0003]
3 - Method for accessing a radio channel according to claim 1 characterized in that it implements at least one GIS signaling channel separate from a data channel DATA and in that the GIS signaling channel takes the mini - RTS and CTS signaling slots, the last slot (S + 2) on the GIS signaling channel is not used, the data channel DATA takes up the 30 data slots and an acknowledgment slot ACK at the end of the frame . 3031271 47
[0004]
4 - Method for accessing a radio channel according to claim 1 characterized in that it uses at least one GIS signaling channel separate from a data channel DATA, a frame is divided into (M + 1) mini-frames MF, the last MF mini-frame (M + 1) has the structure of the frame of claim 3, and in that: - For the GIS channel, we use M first mini-frames each composed of (S + 2) slots, the (S + 1) slots are each composed of a mini-slot for RTS messages and a mini-slot for CTS messages, the last slot contains a mini-slot for partial acknowledgment messages P -ACK and a mini-slot neutralized, - On the DATA channel, we use M first mini-frames each composed of "S + 2" slots, the "S + 1" first slots are for data messages, the last slot "S + 2" consists of a deactivated minislot and a mini-slot for acknowledgment messages ACK.
[0005]
5 - Process according to claim 3 characterized in that the frame F on the signaling channel GIS is composed at the level of the "S + 1" first slots, three mini-slots distributed in the following manner, a first mini-slot MS1 for sending RTS messages, a second mini-slot MS2 for sending messages of type CTS, a third mini-slot MS3 for sending messages of type CAC.
[0006]
6 - Process according to claim 4 characterized in that it uses a frame composed at the level of the "S + 1" first slots of each mini-MF frame on the signaling channel, three mini-slots distributed in the following manner, a first mini-slot MS1 for sending RTS messages, a second mini-slot MS2 for sending messages type CTS, a third mini-slot MS3 for sending messages type CAC, the last slot ( S + 2) of the first M mini-frames on the GIS signaling channel is modified to contain three mini-slots: the first [MS1 (S + 2), SIG] for sending 3031271 48 P-CAC type messages , the second [MS2 (S + 2), SIG] for sending messages of type P-ACK, and the third mini-slot [MS3 (S + 2), SIG] not used, the last slot S + 2 of the first M mini-frames on the data channel DATA is modified to contain three mini-slots: the first two mini-slots 5 are not used MS1, MS2, and the third mini-slot [MS3 (S + 2) , DATA] is reserved for sending ACK messages.
[0007]
7 - Process according to claim 3 characterized in that one uses a frame F supported by "Ns + Nd" separate radio channels (frequency, code, etc ...): "Ns" GIS channels and "Nd" channels DATA where "Nd" is multiple of "Ns": "Nd = P * Ns", - On GIS channels, the frame contains "S + 1" signaling macro-slots RTS / CTS and a last slot not used, each of the signaling macro-slots is composed of "P" slots, and each slot 15 is itself composed of two mini-slots, - the first mini-slot carries messages of the RTS type and the second mini-slot carries messages. messages of the CTS type, - The "i" th slot of each macro-slot on the "n" th signaling channel is used for the exchange of reservation signaling 20 RTS / CTS to access the "d" th data channel such as "d = (n- 1) * P + i", - On DATA channels, the frame contains "S + 1" macro-slots of DATA and a last ACK acknowledgment slot, each of the macro-slots of DATA is him - even composed of "P" DATA slots. 25
[0008]
8 - Process according to claim 7 characterized in that one uses a frame supported by "Ns + Nd" separate radio channels (frequency, code, etc ...): "Ns" GIS channels (signaling) and "Nd" DATA channels (data), where "Nd" is multiple of "Ns": "Nd = P * Ns", 3031271 49 - On GIS channels, the frame is divided into "M + 1" (M> = 0) In the mini-frames, the last mini-frame exactly takes the form of the GIS frame of claim 7, - On the GIS channels, each of the first "M" mini-frames is composed of "S + 2" macro-slots: " S + 1 "RTS / CTS signaling macro-slots and a last P-ACK signaling macro-slot, each of the" S + 1 "macro-signaling slots RTS / CTS is composed of" P "slots, and each of "P" slots is itself composed of two mini-slots, 10 - The first mini-slot carries RTS type messages and the second mini-slot carries CTS type messages, the P-ACK signaling macroslot is composed of "P" s batches that carry P-ACK type messages and a last slot not used, - The "i" th slot of each macro-slot of each mini-frame on the 15 "n" th GIS channel is used for the exchange of RTS / CTS reservation signaling to access the "d" th DATA channel such that "d = (n-1) * P + i", - The "i" th slot of the last P-ACK macro-slot of each mini-slot frame on the "n" th SIG channel is used to send P-ACK message 20 corresponding to the DATA channel "d" such that "d = (n-1) * P + i" - On the DATA channels, the frame also contains "M + 1" (M> = 0) minitrames, the last mini-frame takes the form of the DATA frame of claim 7, - On the DATA channels, each of the "M" first mini-frames is 25 composed of "S + 2" macro-slots: "S + 1" macro-slots of DATA and a last macro-signaling slot ACK, - Each of the "S + 1" macro-slots of DATA is composed of P slots of DATA, the ACK signaling macro-slot is composed of "P" slots not used and a last ACK slot for carrying ACK type messages, the last mini-frame takes the form of the DATA frame of claim 7. 3031271 50
[0009]
9 - Process according to claim 7 characterized in that for the frame on the GIS channels, each slot of the macro-slots is composed of three minislots: a first mini-slot for sending RTS messages, a second mini-slot for sending CTS messages, and a third mini-slot for sending a CAC message.
[0010]
10 - Process according to claim 8 characterized in that the frame is modified on the signaling channels so that each slot of the "S + 1" first macro-slots of each mini-frame on the signaling channels is now consists of three mini-slots: a first mini-slot for sending RTS messages, a second mini-slot for sending CTS messages, and a third mini-slot for sending a message type CAC, the last macro-sIot (S + 2) of the first M mini-frames on the GIS channels is now composed of 2P + 1 slots: P slots P-CAC, P slots 15 P-ACK, and a last non-slot used, the last macro-slot (S + 2) of the first M mini MF frames on DATA channels is changed to contain 2P + 1 slots: 2P unused slots and a last ACK slot.
[0011]
11 - Frame for use in a synchronous network with access TDMA, 20 having an "S + 2" number of slots, characterized in that its structure comprises at least the following elements: - The "S" first slots each contain 2 mini MS1 (s), MS2 (s), the first mini-slot MSI (s) contains a signaling message type RTS or data, the second mini-slot MS2 (s) 25 contains a signaling message CTS or data, - The first mini-slot MS1 (S + 1) of the slot "S + 1" contains an RTS message or data, - The second mini-slot MS2 (S + 1) contains data, - The first mini-slot slot MS1 (S + 2) of slot "S + 2" contains a message of type CTS, 3031271 51 - The second mini-slot MS2 (S + 2) contains an acknowledgment message of type ACK.
[0012]
12 - Frame according to claim 11 characterized in that it further comprises the following elements: - The frame is divided into "M + 1" (M> = 0) mini MF frames (f), - the last mini -Frame FM (F + 1) takes exactly the form of the frame of claim 11, - The "S" first slots of each mini-MF frame each contain 10 two mini-slots MS1, MS2, - the first mini-slot MS1 (s) of each slot contains a signaling message type RTS, or data, - The second mini-slot MS2 (s) of each slot contains a signaling message type CTS, or data, 15 - The first mini-slot of the slot "S + 1" of each mini-frame [MS1 (S + 1), MF] contains an RTS message or data, - The second mini-slot [MS2 (S + 1), MF ] contains the data, - The last slot "S + 2" of a mini-MF frame is defined as follows: - In the "M" first mini-frames: the first mini-slot of slot 20 "S + 2" , MS1 (S + 2) of each MF mini-frame contains messages of type CTS or P-ACK (Partial ACK), the second mini-slot "S + 2", MS2 (S + 2), contains an acknowledgment message of the ACK type, - In the last mini-frame MF (F + 1): the first mini-slot 25 [MS1 (S + 2), MF (F + 1)] of the slot "S + 2" contains a message of the type CTS, the second mini-siot [MS2 ( S + 2), MF (F + 1)] contains an acknowledgment message of the ACK type.
[0013]
13 - Frame according to claim 11 characterized in that it comprises at least the following elements: 3031271 52 - The frame is supported by two separate radio channels, a GIS signaling channel and a DATA data channel, - The GIS channel takes up the mini-signaling slots RTS and CTS organized in S + 1 slots, the last slot S + 2 on the SIG channel is not used, - The DATA channel takes over the S + 1 data slots DATA and the slot Acknowledgment ACK, - The S + 1 signaling slots of the GIS channel correspond to the S + 1 data slots of the DATA channel, the last unused slot on the SIG channel corresponds to the ACK slot of the DATA channel.
[0014]
14 - Frame according to claim 13 characterized in that it comprises at least the following elements - The frame F is divided into "M + 1" (M> = 0) mini-MF frames (1), .., 15 MF (M + 1) on a signaling channel and a separate data channel, - The last MF mini-frame (M + 1) exactly takes the form of the frame of claim 13, - The SIG signaling channel resumes the slots RTS, 20 CTS, and P-ACK, the DATA data channel takes over the data slots and the ACK slots, - On the GIS signaling channel, the first "M" MF mini-frames are each composed of "S" +2 "slots, - The" S + 1 "first slots are each composed of a mini-slot 25 for RTS messages, [MS1, MF, SIG] and a mini-slot for messages CTS, [MS2 , MF, SIG], - The last slot (S + 2) contains a first mini-slot [MS1 (S + 2), MF, SIG] for partial acknowledgment messages P-ACK and a second mini-slot [ MS2 (S + 2), SIG] neutralized (not used) [MSn, 30 MF (M + 1)], 3031271 53 - The last MF + 1 mini-frame exactly takes the form of the frame of the GIS channel of claim 12 except the last slot which contains only a neutralized mini slot, - On the DATA channel, the "M" first mini-frames are each composed of "S + 2" slots, - The "S + 1" first slots are for DATA data messages while the last slot of a mini-frame is composed of a neutralized mini-seated MSn (S + 2) and a mini-slot MSa (S + 2) for the acknowledgment messages ACK, 10-the last mini-frame MF + 1 takes the form of the frame of the The DATA channel of claim 13, except for the last slot which contains only a mini-slot for ACK, MSa (MF + 1) messages.
[0015]
15 - frame according to claim 12 characterized in that for the frame 15 on the signaling channel each slot of the "S + 1" first slots is composed of three mini-slots: a first mini-slot MS1 for sending messages RTS, a second mini-slot MS2 for sending CTS messages, and a third mini-slot MS3 for sending messages type confirmation of access to the channel or CAC. 20
[0016]
16 - Frame according to claim 15 characterized in that the frame comprises M + 1 (M> = 0) mini-frames: - each slot of the "S + 1" first slot of each mini-frame is composed of three mini-slots : a first mini-slot MS1 for sending 25 RTS messages, a second mini-slot MS2 for sending CTS messages, and a third mini-slot MS3 for sending a message type CAC, - the last slot S + 2 of the first M mini-frames on the GIS channel is modified to contain three mini-slots: the first for sending the 30 messages of the P-CAC type, the second for sending the messages of the type P-ACK, and a third unused mini-slot, 3031271 54 - The last slot S + 2 of the first M mini-frames on the data channel DATA is modified to contain three mini-slots: the first two mini-slots are not used, and the third mini-slot is reserved for sending ACK messages. 5
[0017]
17 - Frame according to claim 11 characterized in that it is supported by Ns signaling channels and Nd data channels is multiple of "Ns": "Nd = P * Ns", - On the GIS channels, the frame contains "S + 1" signaling macro-slots RTS / CTS, [GS, SIG] and a last non-used slot Sn (S + 2), each of the signaling macro-slots [GS, SIG] is composed of " P "slots, and each slot is itself composed of two mini-slots RTSn, CTSn, i with n the channel number and i the slot number in a macro-slot GS, 15 - the first mini-slot RTSn, carries messages of the RTS type and the second mini-slot CTSn, carries messages of the CTS type, - The "i" th slot of each macro-slot GS on the "n" th signaling channel SIG is used for the exchange RTS / CTS reservation signaling system for accessing the "d" th data channel such that "d = (n-1) * P + i", - On DATA channels, the frame contains "S + 1" macro -blocks of DATA and a last slot of Acknowledgment ACK S (ACK), Each of the macro-slots of DATA is itself composed of "P" slots 25 of DATA.
[0018]
18 - Frame according to claim 17 characterized in that it is divided into multi-frames and supported by "Ns + Nd" separate radio channels (frequency, code, etc ...): "Ns" GIS channels (signaling) and "Nd" DATA channels 30 (data), where "Nd" is multiple of "Ns": "Nd = P * Ns", 3031271 55 - On GIS channels, the frame is divided into "M + 1" (M> = 0) minitrames, the last MF mini-frame (M + 1) is mandatory and takes the form of the frame of claim 17, - On the GIS channels, each of the "M" first MF 5 mini-frames is composed of "S + 2" macro-slots GS: "S + 1" macro-signaling slots RTS / CTS GS (RTS / CTS) and a last macro-signaling slot P-ACK, GS (P-ACK), - Each of the "S + 1" signaling macro-slots RTS / CTS is composed of "P" slots, and each of the "P" slots itself is composed of two mini-slots, MS2 = CTS ,,, i with n the signaling channel number and i the number or position of the slot in a macro-slot, the first m ini-slot RTSn, i carries RTS type messages and the second mini-slot CTS ,,,; carries CTS type messages, 15 - The P-ACK GS signaling macro-slot (P-ACK,, i) is composed of "P" slots which carry P-ACK type messages and a last unused slot Sn , the last MF mini-frame (M + 1) repeats the construction of the first "M" frames except the last macro-slot which contains only one unused slot [Sn, MF (M + 1)] , 20 - The "i" th slot of each GS macro-slot of each MF mini-frame on the "n" th GIS channel is used for the exchange of RTS / CTS reservation signaling to access the "d" th channel DATA such that "d = (n-1) * P + i", - the "i" th slot of the last macro-slot P-ACK, GS (P-ACKr ,, i) of each 25 mini-frame MF on the "n" th GIS channel is used to send a P-ACK message corresponding to the DATA channel "d" such that "d = (n1) * P + i", - On the DATA channels, the frame also contains " M + 1 "(M> = 0) MF frames, 30 - The last mini-frame exactly takes the form of the DATA frame of the claim - On the DATA channels, each of the first "M" mini MF frames is composed of "S + 2" macro-slots: "S + 1" macro-slots of DATA and a last macro-slot of ACK signaling, - Each of the "S + 1" macro-slots of DATA is composed of P slots of 5 DATA, The macro-signaling slot ACK is composed of "P" slots not used Sn and a last slot ACK to carry ACK-type messages, - The last MF mini-frame (M + 1) repeats the construction of the first "M" except for the last macro-slot [GS (M + 1), ACK] which does not contain now only one ACK slot to carry ACK messages.
[0019]
19 - Frame according to claim 17, characterized in that it is supported by `Ns' SIG channels and 'Nd' distinct DATA channels with a validation of the RTS and in that on the GIS signaling channels each slot of the macro- GS slots now consists of three mini-slots: a first mini-slot MS1 for sending RTS messages, a second minislot MS2 for sending CTS messages, and a third mini-slot MS3 for sending a message of type CAC. 20
[0020]
20 - Frame according to claim 19 characterized in that the frame has a multi-frame structure and in that: - On the GIS channels each slot of the "S + 1" first macro-slot of each mini-frame is now composed three mini-slots: a first 25 mini-slot for sending RTS messages, a second mini slot for sending CTS messages, and a third mini-slot for sending a CAC type message , - The last S + 2 macro-slot of the first M mini-frames on the GIS channels is composed of 2P + 1 slots: P P-CAC slots, P P-30 ACK slots, and a last slot unused, 3031271 57 - The last macro-siot S + 2 of the first M mini-frames on the channels of DATA is modified to contain 2P + 1 slots: 2P unused slots and a last slot ACK. 5

类似技术:

---

公开号 | 公开日 | 专利标题

---

US8031744B2|2011-10-04|Full-duplex wireless communications

---

US7822009B2|2010-10-26|Distributed medium access protocol for wireless mesh networks

---

US7391789B2|2008-06-24|Ad-hoc network wireless communication system and method thereof

---

EP2074754B1|2012-02-01|Automatic partner selection in the cooperative mac protocol

---

CN101197826B|2010-09-01|Method for solving problems of multi-jumping wireless self-network grouping concealed terminal and exposed terminal

---

Acharya et al.2004|Design and analysis of a cooperative medium access scheme for wireless mesh networks

---

EP3041309B1|2019-02-27|Access protocol and method in an ad hoc network

---

Bazan et al.2010|On the design of opportunistic mac protocols for multihop wireless; networks with beamforming antennas

---

Cheng et al.2006|Ripple: A wireless token-passing protocol for multi-hop wireless mesh networks

---

JP2005086570A|2005-03-31|Communication controlling method and communication terminal

---

Sekiya et al.2011|Analytical expression of maximum throughput for long-frame communications in one-way string wireless multihop networks

---

Datsika et al.2015|Adaptive cooperative network coding based MAC protocol for device-to-device communication

---

Liu et al.2003|A reservation-based multiple access protocol with collision avoidance for wireless multihop ad hoc networks

---

EP2198658B1|2011-10-26|A method of reducing occurrence of masked nodes, a node and a computer program product therefor

---

Abdullah et al.2010|Enhanced busy-tone-assisted mac protocol for wireless ad hoc networks

---

Rabarijaona et al.2010|Partnership-based cooperative MAC protocol

---

Ghaboosi et al.2008|Receiver blocking problem in mobile ad hoc networks: Challenges & solutions

---

Wang et al.2006|WSN05-1: A Dual Busy-Tone MAC Scheme Supporting Voice/Data Traffic in Wireless Ad Hoc Networks

---

Garcia-Luna-Aceves et al.2020|Aloha with queue sharing

---

Karabulut et al.2019|CoMACAV: Cooperative MAC Protocol for Autonomous Vehicles

---

Gannapathy et al.2009|Concurrent MAC with short signaling for multi-hop wireless mesh networks

---

Singh et al.2009|Performance modeling of slotted MACA-BI MAC protocol for mobile ad hoc networks

---

Guo et al.2007|Efficient spatial reuse in multi-radio, multi-hop wireless mesh networks

---

Ranjitkar et al.2008|Performance enhancement of ieee 802.11 s mesh networks using aggressive block ack scheme

---

RamMohan et al.2007|A new protocol to mitigate the unheard RTS/CTS problem in networks with switched beam antennas

同族专利:

---

公开号 | 公开日

---

EP3041309A1|2016-07-06|

---

FR3031271B1|2017-12-29|

---

SG10201510771WA|2016-07-28|

---

US10104656B2|2018-10-16|

---

US20160192359A1|2016-06-30|

---

EP3041309B1|2019-02-27|

引用文献:

---

公开号 | 申请日 | 公开日 | 申请人 | 专利标题

---

US20090109938A1|2007-10-31|2009-04-30|Samsung Electronics Co., Ltd.|Method and system for medium access control in communication networks|CN110800237A|2017-05-15|2020-02-14|瑞典爱立信有限公司|Demodulation reference signaling for mini-slots|US7630349B2|2004-03-05|2009-12-08|Ramot At Tel-Aviv University Ltd.|Antenna division multiple access|

---

KR20070098283A|2006-03-31|2007-10-05|삼성전자주식회사|Method and system for allocating resource in a communication system|

---

US9794949B2|2010-07-30|2017-10-17|Board Of Regents, The University Of Texas System|Distributed rate allocation and collision detection in wireless networks|

---

WO2012122508A2|2011-03-09|2012-09-13|Board Of Regents|Network routing system, method, and computer program product|

---

US9838984B2|2013-11-08|2017-12-05|Intel IP Corporation|Power control method and system for wireless networks|

---

US20160381646A1|2013-12-21|2016-12-29|Qinghua Li|Method and system for high density wi-fi communications|

---

EP3122090B1|2014-03-18|2021-03-17|Sony Corporation|Base station and terminal|

---

EP3136787A4|2014-04-22|2017-12-06|Sony Corporation|Device and method|CN107864516B|2017-11-10|2019-12-10|西安电子科技大学|Multi-address access method suitable for density non-uniform state QoS hard guarantee|

---

US11006446B2|2018-05-31|2021-05-11|Qualcomm Incorporated|Traffic scheduling in cellular V2X communication|

法律状态:
2015-11-23| PLFP| Fee payment|Year of fee payment: 2 |

---

2016-07-01| PLSC| Publication of the preliminary search report|Effective date: 20160701 |

---

2016-11-28| PLFP| Fee payment|Year of fee payment: 3 |

---

2017-11-27| PLFP| Fee payment|Year of fee payment: 4 |

---

2018-11-27| PLFP| Fee payment|Year of fee payment: 5 |

---

2020-10-16| ST| Notification of lapse|Effective date: 20200910 |

优先权:

---

申请号 | 申请日 | 专利标题

---

FR1403024A|FR3031271B1|2014-12-30|2014-12-30|METHOD AND PROTOCOL OF ACCESS IN AN AD HOC NETWORK|FR1403024A| FR3031271B1|2014-12-30|2014-12-30|METHOD AND PROTOCOL OF ACCESS IN AN AD HOC NETWORK|

---

EP15202969.0A| EP3041309B1|2014-12-30|2015-12-29|Access protocol and method in an ad hoc network|

---

US14/982,336| US10104656B2|2014-12-30|2015-12-29|Access method and protocol in an ad hoc network|

---

SG10201510771WA| SG10201510771WA|2014-12-30|2015-12-30|Access method and protocol in an ad hoc network|