CN-116367350-B - Binary countdown medium access control method for wireless scene

Abstract

A binary countdown medium access control method for a wireless scene comprises the following steps of step 1, in a competition interval, step 101, generating k-bit random numbers by each node attempting to access, step 102, enabling the node to perform corresponding actions in a corresponding contention micro time slot according to each bit number of the random numbers, step 103, generating a mask by a non-sender node, step 104, enabling the node which does not exit competition to serve as a winner node, step 2, enabling all the non-sender nodes to send contention feedback messages to all the winner nodes, enabling the winner node which is successful in contention to serve as a winner node, and step 3, enabling the winner node to perform data transmission. The invention solves the problem of hidden terminals by utilizing the information mastered by the characteristic nodes, and improves the probability of collision-free access.

Inventors

• XU YANWU
• QIN SHUANG
• LI XIAOQIAN
• FENG GANG

Assignees

• 电子科技大学

Dates

Publication Date

20260512

Application Date

20230411

Claims (5)

1. 1. A binary countdown medium access control method for wireless scene is characterized in that, The time frame period of the wireless scene comprises a plurality of time slots, wherein the time slots sequentially comprise a competition interval, a hidden terminal elimination interval and a data interval from front to back, and the competition interval comprises k contention micro time slots; The control method comprises a competition process of each time slot in each time frame period, wherein the nodes participated in the competition process are all nodes in a single-hop conflict domain, and the competition process comprises the following steps: step 1, in the competition interval, the method is carried out, Step 101, each node attempting to access generates a k-bit random number b= { bi }, i= (1, 2..k); step 102, the node performs corresponding actions in the corresponding contention micro time slot according to each digit of the random number, specifically: if bi=1, the node transmits a contention signal CSi for channel contention; Otherwise bi=0, node X listens to the channel; in the process of monitoring the channel, if other nodes in the channel are monitored to perform channel contention, the nodes abandon the contention in the time slot and exit the contention; Step 103, defining all nodes which exit from contention as non-sender nodes, wherein each non-sender node monitors all contention signals CSI, and when one station is transmitting in a j-th contention micro time slot, the non-sender node generates a mask, wherein the mask is a k-bit character string, the j-th bit is 1, and all other bits are 0; Step 104, the node which does not exit the competition is taken as a winner node to enter step 2; And 2, step 2. If only 1 node does not exit the competition after the step1 is finished, the node directly enters the step 3 as a winner node; Otherwise, go to step 201; step 201. All non-sender nodes send contention feedback messages to all winner nodes, The contention feedback message includes a SID field indicating a slot and an HCM field containing a mask generated in step 103; step 201. Each winner node performs phase-to-phase calculation on the k-bit random number of each winner node and the mask in each HCM field, and if all the results are non-zero, the contention is considered to be successful; A winner node with successful contention proceeds to step 3 as a winner node; Step 3, the winner node sends win information FI to other nodes, wherein the FI information comprises time slot state information in a time frame period acquired in the past and time slot information newly occupied by the winner node, and the other nodes update and record the time slot states in the time frame period according to the win information FI; the winner node transmits data.
2. 2. The control method as set forth in claim 1, wherein in step 201, the time for the non-transmitting node to transmit the contention feedback message to all the winner nodes is: if the node is the node which gives up the contention, the node is sent in a hidden terminal elimination interval; if the node is the node which performs the node access, the node transmits in the time slot with successful contention.
3. 3. The control method of claim 2, wherein the hidden terminal cancellation interval includes a plurality of cancellation micro-slots, and the node that gives up contention randomly selects one cancellation micro-slot to transmit.
4. 4. The control method of claim 1 wherein the non-sender node further comprises a winner node of other time slots.
5. 5. The control method of claim 1, wherein the contention signal CSi is MAC address information of a node.

Description

Binary countdown medium access control method for wireless scene Technical Field The invention belongs to the technical field of software, relates to a wireless data transmission technology, and particularly relates to a binary countdown medium access control method for a wireless scene. Background A wireless ad hoc network (WIRELESS AD hoc Networks, WANET) is an autonomous system of network nodes connected by wireless links. The node relationships in the network are peer-to-peer and wireless communication can take place without the need to establish a fixed infrastructure. In the communication process, the node generates traffic demand and transmits data as a mobile terminal, and physical broadcasting cannot cover all terminals due to the limitation of radio range, and also a multi-hop situation must be considered, that is, the node acts as a router to relay data from other nodes at the same time. As WANET has the advantages of self-establishment, self-organization, self-management and the like, the wireless network deployment method is suitable for being applied to the scenes of military battlefields, disaster search and rescue, environment monitoring, intelligent driving, medical care and the like without establishing a base station or a fixed infrastructure to achieve rapid wireless network deployment. Because of the high variability of the environment, all protocols and coordination functions must be fully distributed in WANET, so that the functions such as transmission synchronization or collision detection cannot be performed by means of the central controller. Furthermore, due to the distributivity of the environment, collisions between transmissions may occur only on a part of the recipients, which feature further brings about the so-called hidden terminal problem. WANET-oriented medium access control (Medium Access Control, MAC) protocols are largely classified into two types, allocation-based and contention-based, in a wireless channel access coordination manner. The allocation class protocol needs to allocate resources to each node, and the implementation cost of the protocol is generally large. Depending on the allocated resources, it can be classified into FDMA-based, TDMA-based, and the like types. The allocation type protocol refers to that the divided resources are fixedly allocated to specific nodes, and the division mode generally ensures that the resources used by different nodes are not overlapped. The fixed allocation type protocol has the advantages of ensuring fairness of data transmission of each node and controllable protocol overhead. The method has the defects that when the network scale is large, the cycle period of a time frame needs to be prolonged, the network delay is increased, if the number of active nodes in the network is small, excessive idle resources are caused, and only when the proportion of the active nodes in the network is large enough, the channel resources can be fully utilized. And the fixed allocation type protocol has a disadvantage in that it is difficult to implement QoS support and channel utilization is low. In the contention-type protocol, the node can dynamically contend for resources according to different service requirements and channel occupation conditions. However, when the network load is large, the collision probability generated by the traditional contention-based protocol is greatly increased, the channel access time delay of each node is also greatly increased, and the protocol performance is rapidly reduced. A typical scheme is to use CSMA and RTS/CTS to sense channel conditions and contend for access to the wireless channel, the representative protocol being 802.11p MAC. The partial concepts of the present invention are explained as follows: The binary countdown protocol (Binary Countdown Protocols), also known as the master protocol (Dominance Protocols), was originally proposed in the 20 th century, 70, to address wired network medium access conflicts, and has now evolved into an important class of algorithms to address arbitration problems, for use in a variety of fields. Topology-Transparent (Topology-Transparent), meaning that network nodes do not need to master the network Topology. A protocol scheme can operate without the network node having knowledge of the network topology, and is said to be topologically transparent. The hidden terminal problem (Hidden node problem/HIDDEN TERMINAL problem) is that in the communication field, a wireless node A sends information to a node B, and a node C does not detect that A also sends information to B, so that A and C send signals to B simultaneously, transmission collision is caused, and finally, the signals sent to B cannot be decoded, and the information transmission of A and C fails. Time division multiple access (Time division multiple access, TDMA) is a communication technology for implementing a shared transmission medium (typically in the radio domain) or network. It allows multiple use