• 专利附录
  • 专利说明
  • 权利要求
  • 类似技术
  • 同族专利
  • 引用文献
  • 法律状态
  • 优先权
    • 专利摘要:
    According to the present invention, when a media access controller transmits a plurality of frames to a transmission line through a physical connection in a fast Ethernet collision apparatus having a media access controller and a physical connection, a specific code is generated by generating a specific code in an interframe gap existing between frames. It is to distinguish the interval from the interframe gap.
    公开号:KR20000027713A
    申请号:KR1019980045711
    申请日:1998-10-29
    公开日:2000-05-15
    发明作者:오순석
    申请人:윤종용；삼성전자 주식회사；
    IPC主号:
    专利说明:

    Fast Ethernet Collision Avoidance Device and Method
    The present invention relates to an apparatus and method for preventing collision of fast ethernet. More specifically, the present invention relates to an interframe gap (hereinafter referred to as 'IFG') occurring between a plurality of frames. An anti-collision device and a method thereof are provided.
    Originally developed, Ethernet continued to grow rapidly, driven by the explosive growth of personal computers, and dominated the local area network (LAN) market. At the same time, the development of technology has been in earnest, and high-speed data communication networks of 100Mb / s and 1000Mb / s have emerged. However, this technology development has been focused on the physical layer, which is the first layer of OSI (open system integration). Therefore, while the development and commercialization of the high-speed physical layer has progressed, the products of the media access controller (hereinafter referred to as 'MAC') are using the protocol at the time of development with little modification. In recent years, the personal computer has been improved in performance and the host demand of the local area network has expanded, and the existing MAC protocol, carrier sense multiple access / collision detection (CSMA / CD), causes many problems in the current communication environment.
    When multiple hosts transmit data on a network, there may be a collision between data transmitted at the same time. When such a collision occurs, a bit of collision signal is transmitted to each host side on the network. Each host that receives the collision signal retransmits the data by the retransmission algorithm. At this time, as the retransmission algorithm, an algorithm called binary exponential backoff (hereinafter referred to as 'BEB') is mainly used. The BEB algorithm is an algorithm for determining the constant delay time when retransmitting data after a certain delay time at the time of collision. The constant delay time is extended by a multiplier of 2 whenever a collision occurs.
    For example, if HostA first transmits data on the network and then first encounters a collision, it retries again one minute later. Here, after Host A tries to retransmit, it attempts to retransmit after 2 minutes if a second collision occurs, and retransmits after 4 minutes if a third collision occurs. However, this BEB algorithm has a problem that violates network fairness. In other words, host A tries to retransmit after a 4 minute delay due to a third collision. Here, if the host B transmits data while the host A is delayed for the next retransmission, the data is transmitted before the host A. In addition, when Host A transmits data first and Host B transmits data later, there arises a problem of violating fairness on the network. In other words, the BEB algorithm results in a host that attempts to transmit data later than a host that attempts to transmit the data occupies the network first and transmits the data. This problem, collectively called the capture effect, is a major factor in network performance degradation. The capture effect is a structural problem of the CSMA / CD method, which is a serious problem when the number of hosts in a network increases rapidly or a large amount of data is transmitted.
    To solve this problem, the CABB (capture avoidance binary exponential backoff) algorithm and the binary logarithmic arbitration method (BLAM) algorithm have been developed to improve the BEB algorithm. These algorithms basically use the BEB algorithm and are an improvement on how to calculate the latency for collision avoidance. However, these algorithms do not completely solve the above problems that violate the fairness of the network.
    In addition, there is a method called collision truncation in which a relay such as a hub or repeater on a network detects a collision signal in advance and transmits a collision signal to a host when a collision occurs. This method reduces the delay time for collision signals to be delivered to each host side, thus preventing the network from degrading. However, this method also improves network performance but does not solve the problems of collision and fairness violation.
    As described above, the above techniques do not fundamentally solve a collision, which is a fundamental problem of the conventional network, and thus still inherent problems of network performance degradation. In particular, when the traffic of the network increases, the data cannot be transmitted beyond the maximum transmission time and information is lost. If such a phenomenon occurs, the solution can be solved only at a higher layer, thereby reducing the overall efficiency of the network.
    Accordingly, an object of the present invention is to improve the performance of the network by preventing collisions in advance to solve the existing problems, to solve the existing capture effect and to ensure the fairness of the network. That is, an object of the present invention is to insert a specific code into the interframe gap to inform that the data is being transmitted over the network, and other hosts receive the specific code and operate the internal counter to prevent collisions occupying the network in order according to the counter value An apparatus and a method thereof are provided.
    1 is a frame transmission diagram of Fast Ethernet.
    2 is a frame transmission diagram of Fast Ethernet according to an embodiment of the present invention.
    3 is a specific code representing an interframe gap according to an embodiment of the present invention.
    4 is a block diagram of a collision avoidance apparatus according to an embodiment of the present invention.
    5 is a transmission flowchart for collision avoidance according to an embodiment of the present invention.
    6 is a reception flowchart for preventing a collision according to an embodiment of the present invention.
    In order to achieve the above object, the present invention provides an interframe existing between frames when a media access controller transmits a plurality of frames to a transmission line through a physical connection in a collision device of a fast Ethernet having a media access controller and a physical connection. A specific sign is generated in the gap to distinguish the idle period from the interframe gap.
    A configuration in accordance with aspects of the invention comprises a media access controller, a transmitter, a code generator, a receiver and a counter. Here, the media access controller generates data for transmission and divides it frame by frame. The transmitter is a physical connection, and electrically applies data to the transmission line in units of frames. The code generator generates a specific code that is distinguished from an idle interval in the interframe gap between frames. In addition, the receiver converts an electrical signal received in units of frames in the transmission line as a physical connection unit and transmits the data. The counter operates by receiving a specific sign generated in the interframe gap. Here, the specific code consists of a start section indicating the start of the interframe gap, a clock section providing a clock required for the counter to operate, and an end section indicating the end of the interframe gap. The counter is initialized by the start interval of a particular sign, counted according to the clock of the clock interval, terminates counting by the end interval, and passes the counter value to the media access controller. Thus, the media access controller receives the counter value to determine the priority for data transfer.
    In addition, the present invention may further include a transmission data path unit for transferring data from the media access controller to the transmission unit.
    In addition, the present invention may further include a reception data path unit for transmitting the data received in the transmission line to the media access controller.
    A method for achieving the present invention includes a first step of generating data to be transmitted and forming a frame according to a data length; Determining whether to send one frame; A third step of transmitting a specific code in an interframe gap section after transmitting the first frame among a plurality of frames when transmitting in one or more frames; When transmitting in one frame, a fourth step of transmitting the frame is performed.
    In addition, the above method for achieving the present invention includes a fifth step of the host to monitor the transmission line for transmitting data; A sixth step of performing counting according to a clock signal of the specific code and outputting a counter value when the host receives the specific code in the interframe gap period; And a seventh step of determining the priority according to the counter value and retransmitting the data by the host according to the priority.
    Hereinafter, an apparatus and method for preventing collision of Fast Ethernet according to an embodiment of the present invention will be described with reference to the accompanying drawings.
    1 is a frame transmission diagram of Fast Ethernet, in which there is an idle period, a frame, and an IFG period between frames. The idle period represents an idle period in which no data is transmitted on the network. The frame shown here means that data transmitted by the same host is divided into three frames. In addition, there is an IFG section between frames. Here, the sign indicating the idle section and the sign indicating the IFG section are the same. Accordingly, the host transmits data by detecting a carrier in an idle period or an IFG period.
    In order to prevent a collision, the present invention generates a specific code for distinguishing an IFG section from an idle section in which data transmission does not occur. In addition, the BEB algorithm is improved by using a specific code generated in the IFG interval to prevent collisions between a plurality of hosts.
    Therefore, the following describes the present invention having the features as described above.
    2 is a specific code representing an interframe gap according to an embodiment of the present invention.
    As shown in FIG. 2, the length of the entire IFG section is 96 bits, the first 10 bits indicate the IFG start section, the 80 bits following the clock, and the remaining 6 bits indicate the IFG end section. Here, the clock is selected to repeat in the form of "110011" so that the actual number of clocks is 20. In this case, the clock number 20 is to allow a maximum number of retransmission attempts 16 of the BEB algorithm specified in Institute of Electrical and Electronics Engineers (IEEE) 802.3 described below.
    3 is a frame transmission diagram of Fast Ethernet according to an embodiment of the present invention.
    As shown in Fig. 3, Host A, Host B, and Host C are connected to the network and attempt to transmit data. Host A checks the transmission line status at interval t1. At this time, since the transmission line state is an idle period, the host A starts transmitting data from the t2 interval. Data transmitted by the host A is divided into two frames and transmitted. In this case, the first frame is transmitted in the interval t2, the specific code indicating the IFG interval is transmitted in the interval t3, and the second frame is transmitted in the interval t4. After completing the data transmission, the host A repeatedly transmits a code " 101010 ... "
    Meanwhile, the host B and the host C check the transmission line for data transmission at the same time in the period t3. At this time, in the conventional technology, the host B and the host C receive a repeated sign "101010 ..." indicating that the IFG section is in section t3, and the collision occurs by the host B and the host C simultaneously transmitting data in section t4. Occurs. However, according to the present invention, the host B and the host C receive a specific sign indicating that the IFG section is at the same time in the t3 section. Here, as shown in Fig. 2, the host B and the host C receive a clock signal in the IFG section and operate their respective internal counters. Therefore, since the host B detects the transmission line in the IFG section before the host C, the counter is immediately operated so that the counter value becomes larger than the counter value of the host C.
    In accordance with the provisions of IEEE 802.3, the BEB algorithm to avoid collisions is as follows.
    0≤r≺2 k
    Where k = min (n, 10)
    At this time, n means that both Host B and Host C have '1' according to IEEE 802.3. Next, Host B and Host C having the same n value compare the counter values to determine the priority. In this case, since host B has a larger counter value, the host B has a higher priority, and thus, host A starts data transmission at interval t5 after the data transmission ends. Next, the host C transmits data at interval t6.
    Hereinafter, internal structures of the host A, the host B, and the host C operating as shown in FIGS. 2 and 3 will be described.
    4 is a block diagram of a collision avoidance apparatus according to an embodiment of the present invention.
    As shown in FIG. 4, the present invention provides the MAC 100, the transmission data path unit 200, the code generator 300, the transmission unit 400, the reception unit 500, the reception data path unit 600 and the counter ( 700).
    The MAC 100 is responsible for data generation and media management according to IEEE 802.3. In addition, the transmitter 400 serves as a physical layer connection unit, converting transmission data into an electrical signal and applying it to a transmission line. The receiver 500 receives an electrical signal from a transmission line and converts the signal into data. The transmission data path unit 200 is positioned between the MAC 100 and the transmitter 400, which is a physical layer connection unit, and transmits data transmitted from the MAC 100 to the transmitter 400. At this time, the code generator 300 generates a specific code as shown in FIG. 2 in the IFG section between the frames. A reception data path unit 700 is positioned between the physical layer connection receiver 500 and the MAC 100 to transfer the data received by the receiver 500 from the transmission line to the MAC 100. At this time, the counter 700 is initialized by recognizing the start section of the specific code indicating the IFG section to start the operation, perform the counting according to the clock signal, and end upon receiving the end section.
    5 is a transmission flowchart for collision avoidance according to an embodiment of the present invention.
    The MAC 100 generates data to be transmitted and analyzes the data length (S100) to determine whether to send one frame (S110). When the amount of data to be transmitted is transmitted in one or more frames, the code generator 300 is activated (S120). Next, the first frame is transmitted from among the data divided into a plurality of frames (S130). The code generator 300 transmits a specific code as shown in FIG. 2 in the IFG section (140). Again, the routine in which the second frame is transmitted and the particular code is sent in the IFG interval is repeated until all of the data is transmitted.
    On the other hand, if the amount of transmission data is small and can be transmitted in one frame, the code generator 300 is placed in a standby state (S150). Next, the data is transmitted to the transmission unit 400 via the transmission data path unit 200 and converted into electrical signals and applied to the transmission line (S160).
    6 is a reception flowchart for preventing a collision according to an embodiment of the present invention.
    The host monitors the transmission line to send data. At this time, when the host receives the specific code as shown in FIG. 2 in the IFG period, the counter 700 is initialized and activated. Next, the counter 700 performs the counting according to the clock signal of a specific code and transmits the counter value to the MAC when receiving the end section. Here, the MAC determines the priority according to the received counter value. Each host retransmits data in the corresponding interval according to the priority.
    In the above, the collision preventing device of Fast Ethernet has been described, but the collision preventing device of the present invention is not limited to Fast Ethernet.
    In addition, although embodiments of the present invention have been described using IEEE 802.3 frames as an example, the present invention is not limited to the above-described IEEE 802.3 frames, and of course, the present invention is applicable to Ethernet using various Ethernet protocols such as IEEE 802.4 and IEEE802.5. to be.
    As described above, according to the present invention, a MAC is attempted to retransmit data by generating a specific code in the IFG section and transmitting a counter value to the MAC by embedding a counter operating according to a clock signal of the specific code. It prevents delays and network oligopoly by certain hosts. In addition, it ensures fairness between the host that preempts the transmission line after the collision and the host that failed.
    权利要求:
    Claims (14)
    [1" claim-type="Currently amended] A media access controller for generating and dividing data into frames for transmission;
    A transmitter for physically applying the data to the transmission line in units of frames as a physical connection unit;
    A code generator for generating a specific code distinct from an idle section in the interframe gap between the frames;
    A receiver which converts an electrical signal received in units of frames in a transmission line into physical data and transmits the data;
    And a counter operating by receiving the specific code generated in the interframe gap.
    [2" claim-type="Currently amended] In claim 1,
    And a transmission data path unit for transmitting the data from the media access controller to the transmission unit.
    [3" claim-type="Currently amended] In claim 1,
    And a receiving data path unit for transmitting the data received from the transmission line to the media access controller.
    [4" claim-type="Currently amended] In claim 1,
    The specific code is,
    A start period indicating the start of the interframe gap;
    A clock period providing a clock required for the counter to operate;
    The end of the interframe gap is a collision prevention device of Fast Ethernet, characterized in that the end section consisting of.
    [5" claim-type="Currently amended] In claim 4,
    The counter is initialized by the start section of the specific code and counted according to the clock of the clock section, and ends the counting by the end section and transmits a counter value to the media access controller. Prevention device.
    [6" claim-type="Currently amended] In claim 5,
    And the media access controller determines the priority for data transmission by receiving the counter value.
    [7" claim-type="Currently amended] In claim 6,
    And the counter value is used as a coefficient of a backoff algorithm.
    [8" claim-type="Currently amended] In the collision device of Fast Ethernet having a media access controller and a physical connection,
    When the media access controller transmits a plurality of frames to the transmission line through the physical connection portion, the media access controller generates a specific code in the interframe gap existing between the frames to distinguish the idle period from the interframe gap. Anti-collision device on Ethernet.
    [9" claim-type="Currently amended] In claim 8,
    The specific code is,
    A start period indicating the start of the interframe gap;
    A clock period providing a clock required for the counter to operate;
    The end of the interframe gap is a collision prevention device of Fast Ethernet, characterized in that the end section consisting of.
    [10" claim-type="Currently amended] In claim 9,
    A counter initialized by the start section, the clock section counted according to a clock, and the counting ends by the end section,
    And said counter value is used to determine priority for data transmission.
    [11" claim-type="Currently amended] In claim 10,
    And the counter value is used as a coefficient of a backoff algorithm.
    [12" claim-type="Currently amended] Generating a data to be transmitted and forming a frame according to the data length;
    Determining whether to send one frame;
    A third step of transmitting a specific code in an interframe gap section after transmitting the first frame among a plurality of frames when transmitting in one or more frames;
    When transmitting in one frame, the collision prevention method of Fast Ethernet, characterized in that the fourth step of transmitting the frame.
    [13" claim-type="Currently amended] In claim 12,
    And the third step is repeated until all the data is transmitted.
    [14" claim-type="Currently amended] In claim 12,
    A fifth step of the host monitoring the transmission line for transmitting data;
    A sixth step of performing counting according to a clock signal of the specific code and outputting a counter value when the host receives the specific code in the interframe gap period;
    And specifying a priority according to the counter value and retransmitting the data by the host according to the priority.
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    同族专利:
    公开号 | 公开日
    US6778551B1|2004-08-17|
    KR100274550B1|2000-12-15|
    引用文献:
    公开号 | 申请日 | 公开日 | 申请人 | 专利标题
    法律状态:
    1998-10-29|Application filed by 윤종용, 삼성전자 주식회사
    1998-10-29|Priority to KR19980045711A
    2000-05-15|Publication of KR20000027713A
    2000-12-15|Application granted
    2000-12-15|Publication of KR100274550B1
    优先权:
    申请号 | 申请日 | 专利标题
    KR19980045711A|KR100274550B1|1998-10-29|1998-10-29|Device and method for protecting a collision of a fast ehternet|
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