Message broadcast-oriented MAC (Media Access Control) layer improving method in VAENT (vehicular Ad-hoc NETwork)

Abstract

The invention belongs to the technical field of mobile communication and relates to a message broadcast-oriented MAC (Media Access Control) layer improving method in an VAENT (Vehicular Ad-hoc NETwork). For a stream media message, an RTB/CTB (request-to-broadcast/clear-to-broadcast) mechanism is used to select a relay vehicle; an ARC-SMB (Adaptive Rate Control-Streaming Media Broadcasting) method is provided in order to guarantee the smoothness of receiving stream medium data by a user; according to a detected channel transmitted data frame state, a broadcast vehicle adjusts data transmitting speed, so that the packet loss rate is reduced; the concept that the user manually adjusts the quality required by a stream media is provided in order to improve the user experience. The state of broadcasting a safety message in an actual environment is simulated, so that the vehicle acquires better delivery rate, single-hop delay is reduced, and the load rate is reduced; the broadcasting state of the safety message in the actual environment can be simulated by the ARC-SMB method, so that the vehicle acquires better delivery rate, the packet loss rate is reduced, and more smooth stream media transmission is provided for the user.

Description

technical field [0001] The present invention belongs to the technical field of mobile communication. In VANET (Vehicular Ad-hoc NETwork), broadcast message content mainly includes safety message and streaming media message. How to effectively manage and transmit these two kinds of messages is a very important problem. Aiming at the safety message, mainly to solve the problem of relay vehicle selection, the DVO-SB method is proposed, which selects relay vehicles by considering the distance between vehicles, vehicle speed and vehicle driving direction. For streaming media messages, the RTB / CTB (Request-to-broadcast / clear-to-broadcast) mechanism is used to select relay vehicles. In order to ensure the fluency of users receiving streaming media data, the ARC-SMB method is proposed. According to the detected In the case of channel transmission of data frames, the broadcast vehicle adjusts the data transmission rate to reduce the packet loss rate; in order to further improve the use...

AI Technical Summary

Problems solved by technology

But the quality of the received video is not guaranteed, and the influence of channel conditions is not considered (Flexible broadcasting of scalable video streams for different mobile devices, C.-H.Hsu, M.M. Hefeeda. Flexible broadcasting of scalable video streams to heterogeneous mobile devices .IEEE Trans.Mobile Comput.,2011,10(3):406–418.); Considering diverse broadcast users, target distortion measurement based on principal component analysis of distance between frames to optimize broadcast process

However, this mechanism does not have a channel adaptive extension suitable for SVC (source coding rate) (node-channel joint coding and optimization for hierarchical video broadcasting of different devices, W.Ji, Z.Li, Y.Chen.Joint source-channel coding and optimization for layered video broadcasting to heterogeneous devices.IEEE Trans.Multimedia,2012,14(2):443–455.); a layered optimization framework to improve user QoE (Quality of Experience) during streaming media broadcasting and save energy usage (node ​​optimization considering user experience and energy utility in wireless multimedia broadcasting, Chetna Singhal, Swades De, Ramona Trestian, Gabriel-Miro Muntean. Joint Optimization of User-Experience and Energy-Efficiency in Wireless Multimedia Broadcast.IEEE Trans.on mobile computing,2014,13(7):1522-1535.)

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