Handover Scheme In Millimeter Wave WiFi Distribution Networks

With the rapid development of mobile multimedia services,users are increasingly demanding data rates,and the current crowded low frequencies are no longer able to meet the bandwidth requirements.In order to solve this problem,millimeter wave has become a hot topic of concern and research.For lower frequency communications,millimeter wave can meet many high data rate applications,such as smart home,AR/VR,wireless HDTV and so on.However,the millimeter wave also has the problem of large path loss and weak link robustness,which brings new challenges to the millimeter wave network handover.This paper will focus on the handover problem in IEEE 802.11 ay millimeter-wave distributed networks.Firstly,the thesis analyzes the time-division beam scanning and time slot resource scheduling mechanism in millimeter-wave WiFi distributed networks.Since the network uses a directed-oriented time-division beamforming process,the entire training takes a long time,this can cause long-term service interruptions during the handover process.The existing IEEE 802.11 handover technology does not adapt well to the handover process under the network architecture,so it is necessary to study the handover scheme which is suitable for the characteristics of the distributed network.Based on this problem,this thesis proposes a mechanism to reduce the handover delay in millimeter-wave WiFi distributed networks,and designs the corresponding flow and frame structure.Through the analysis of specific handover scenarios,the scheme can greatly reduce the delay of handover and improve the performance of the network.Then,the handover scheme of multi-link cooperation in dense millimeter-wave WiFi distributed networks is studied.Different from the conventional single-link,the handover in the scenario of multi-link cooperation is the handover between different cooperation sets.In this thesis,the different division and construction methods of cooperative sets under this architecture are studied.The corresponding link measurement methods and handover strategies are given.Based on the characteristics of time slot resource scheduling in distributed networks,this thesis proposes a multi-link cooperative handover selection strategy combining load information,and the proposed scheme is adopted to maximize the throughput of the network under the premise of controlling the number of handovers during the handover process.