Research On Key Technologies Of Reliable Transmission In Distributed Multi-Hop Ad Hoc Networks

The distributed wireless Ad hoc network is characterized by low cost,flexible networking and strong scalability.It has broad application prospects in ultra-dense networking and other scenarios of the 5^thgeneration mobile communication system.However,most of existing research on distributed wireless Ad hoc network studies single-hop services,while the network itself inevitably transmits multi-hop services.In multi-hop services transmission,probability of successful transmission can vary because of different channel condition of each hop.Therefore,end-to-end transmission performance depends on the worst hop.Existing research on reliability services in distributed wireless multi-hop Ad hoc network mainly focuses on network layer routing protocol algorithms and physical layer redundant reliable transmission mechanisms by analyzing system overhead,fairness,and partial delay.Nevertheless,the difference of multi-hop links and the analysis of end-to-end delay and resource efficiency of services after adopting reliability scheduling methods based on time division multiple access?TDMA?mechanism are seldomly considered,and verification and application of related resource scheduling mechanisms are also lacked.This research aims at practical application of distributed wireless multi-hop Ad hoc network and examine the media access control?Media Access Control,MAC?end-to-end performance of service in distributed wireless multi-hop Ad hoc network through theoretical modeling analysis and mechanisms design,optimization,and verification.Firstly,a variety of point-to-point single-hop and end-to-end multi-hop reliable transmission resource scheduling mechanisms were designed,and services performance models such as overall delay and resource utilization were established to perform comparative analysis.Secondly,control messages,data messages and acknowledgement messages mechanisms were designed and optimized to improve network reliability,ensure resource efficiency and reduce latency.Finally,fully combined communication flow between the MAC layer and other layers of the protocol,the point-to-point and end-to-end reliable transmission resource scheduling mechanisms of the MAC layer based on a distributed verification and simulation platform?VSP?were implemented and analyzed.Theoretical modeling analysis results revealed that,when the channel quality is poor in single-hop scenario,to maximize resource efficiency within time limit,reservation multiple binding pairs of data messages and acknowledgement messages mechanism should be used under constraint of number of business parallels.When the channel quality is good,data messages and acknowledgment messages can use a larger time slot interval to achieve better resource efficiency.Especially when node density is large,the overall delay and efficiency performance of resource scheduling mechanisms proposed in this paper outperform that of the traditional TDMA multiple access mechanism.In a multi-hop scenario,a scheduling mechanism with more service maintenance hops can achieve higher resource efficiency,and a scheduling mechanism with fewer business maintenance hops can achieve lower end-to-end latency.The mechanisms verification analysis results indicated that,the point-to-point single-hop and end-to-end multi-hop reliable transmission scheduling mechanisms proposed in this paper can achieve approximately zero packet loss rate and low latency when the channel condition is ideal.Even when the channel quality is poor,it has a great advantage over a system without a reliable transmission mechanism.A less complex and more effective flexible multi-hop reliable transmission resource scheduling algorithm was designed in this paper,so that the transmission reliability is no longer limited to the worst link when the multi-hop transmission link is differentiated.In addition,an implicit acknowledgment messages mechanism proposed in this paper also improves the communication efficiency.These research results can serve as useful references in practical engineering applications for distributed wireless multi-hop Ad hoc networks.