Novel media access mechanism and channel cooperation method for MAC layer of Internet of vehicles

Abstract

The invention relates to a novel media access mechanism and channel cooperation method for an MAC layer of Internet of vehicles and belongs to the technical field of Internet of vehicles. The method comprises the following steps that an RSU drive test unit is repositioned to enable a network to balance and schedule and distribute resources reasonably; a new time slot region is divided, the adaptability is better while the performance requirements are met, even if the vehicle node density reaches a saturation value, the secure message transmission can be also guaranteed to a certain degree; through a non-timely and asynchronous reserved communication mode, more channel resources are saved, and meanwhile, the interference and the collision of different messages are avoided; and a strategy for active compensation is provided, so that the reliability of the secure message transmission is further enhanced. Through a control unit, unified management is carried out on the whole WBSS network resource and information; in comparison with the conventional IEEE1609.4 channel cooperation mode, the safety performance is improved to a larger extent, and the idle channel resources are further utilized on the basis of avoiding the data collision.

Description

technical field [0001] The invention belongs to the technical field of the Internet of Vehicles, and relates to a new media access mechanism and channel cooperation method of the MAC layer of the Internet of Vehicles. Background technique [0002] In 2004, the DSRC standardization work was officially transferred to the IEEE working group, and then IEEE proposed a set of standards called WAVE / DSRC on the basis of the previous work. The main purpose of this standard is to make it suitable for high-speed mobile environments. Provide services such as traffic management, traffic safety and entertainment. [0003] The VANET system consists of three entities, including Road-Side Units (RSU), OnBoard Unit (OBU) and Dedicated Short Range Communication (DSRC). Therefore, according to the different types of the two parties in the direct data exchange, there are 4 communication methods. [0004] 1) Vehicle-to-vehicle communication (V2V), where vehicles communicate through on-board uni...

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Problems solved by technology

[0012] Bandwidth waste problem: 1) When vehicles interact with the CCH channel of CCHI, the SCH channel is completely wasted, and the CCH of SCHI (SCHinterval) also wastes to a certain extent; You must continue to wait for the arrival of SCHI, and you cannot take other actions before changing

[0013] Insufficient bandwidth margin: When the vehicle density is high, not only cannot provide enough SCH channel resources stably, but may even cause the CCH channel length to fail to meet the use of nodes, resulting in the loss of safety messages

[0014] Collision avoidance mechanism problem: 1) WAVE adopts the CSMA / CA backoff mechanism, which is a mechanism of listening first and then transmitting. As long as the channel is detected to be busy, backoff will occur, and continue to monitor until the counter becomes 0, reaching the idle threshold This method greatly increases the delay; 2) The nodes after backoff may collide again after the timing ends, causing the colliding parties to back off again, resulting in a waste of channel resources, and even making a node unable to get Transmission opportunity; 3) In the CCH channel of the CCH time slot, generally at least two data types need to be released and received, security data and channel reservation data, such two types of data will interfere with each other, and when there are many vehicle nodes, Appointment messages will even occupy the release of security messages, causing serious security incidents

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