Optimization Design And Analysis Of Simulcast RoF-DAS WLAN Access Control Strategy

With the rapid development and popularization of high-speed wireless communication and advanced network technology,the convenient and amount of information interaction between people and things as well as between things sharply increased,and higher requirements have been proposed on the flexibility,resource utilization and service quality of communication networks.On the one hand,how to efficiently utilize the existing bandwidth resources of the network,and on the other hand,the traffic increasing caused by the increasing users desires for higher requirements on network delay and throughput.RoF-DAS has the advantages of high-capacity,low-loss fiber transmission and wireless access flexibility,wide coverage.Therefore,with the current explosive growth of network bandwidth demand,RoF-DAS has become an important solution for wireless communication technology.Combining RoF-DAS with WLAN can effectively improve the traditional WLAN coverage problem,but fiber access will introduce additional delays and reduce the throughput performance of the current network,making the use of the existing WLAN MAC protocol less effective.Research on MAC protocols is imperative.This paper proposes an optimization analysis of the MAC protocol based on the polling control model.Based on the most of existing performance analysis models focus on the single-directional communication scenario,a hybrid service bidirectional polling model is first proposed.To improve energy efficiency,the downlink data queue is assigned after all the uplink station queues,which allows the uplink station to sleep after it completes the data transmission,and it can remain in the sleep state until the downlink begins to broadcast.Then,a classical two-queue asymmetrical polling model is employed of the bidirectional access control system,and a Markov chain and generating function are used to derive a closed-form expression of the mean access delay for the uplink and downlink data.The simulation experimental results show that the improvement on the delay of uplink transmission and energy reduction on stations is at the cost of the downlink resource occupation.Then,in order to ease the above problems,we propose a polling-based scheduled full-duplex MAC protocol.In this protocol,information is pre-collected by the AP before the data transmission,and the scheduling process and transmission process are processed in parallel,at the same time,in order to make corresponding adjustment to changes in the station queuing state,the implementation of the scheduling strategy depends on the amount of data packets to be sent in the station,and the gated and semi-gated policy are adopted.The simulation results show that the scheduled full-duplex MAC protocol can effectively improve the network performance.