Research On The Frame Aggregation In IEEE 802.11 MAC

Wireless Local Area Network(WLAN),as an important research area of wireless communication,has become the first choice of users to access the Internet due to its convenience and high throughput.To improve the backward compatibility of criterion and to achieve higher utilization of high-speed transmission technology,the frame aggregation mechanism is introduced in IEEE 802.11 n and the subsequent standards.More explicitly,WLAN's requirements of the high throughput,the diverse Quality of Service(QoS)for flexible multi-user multi-service access,as well as multimedia applications transmission impose challenge on Media Access Control(MAC)technique for aggregating multi-service and on technique for higher throughput.Therefore,it is of great scientific and practical values to investigate the multi-service in frame aggregation of MAC.This paper focuses on the frame aggregation mechanism of IEEE802.11n/ac in WLAN MAC.Based on analyzing the performance of frame aggregation,we propose two improved methods as follows.1.A frame aggregation mechanism relying on real-time service is proposed for multi-service model,for the sake of satisfying the QoS of delay-sensitive services and obtaining higher efficiency.Furthermore,we conceive a frame aggregation algorithm based on utility function and services characteristics,by exploiting the timing characteristic of voice service.More explicitly,the proposed algorithm separates the services into the voice service and the non-voice service,then builds a utility-based frame aggregation scheduling,which is further solved by the heuristic algorithm.Theoretical analysis and simulation results indicate that,compared with the conventional frame aggregation mechanism,our proposed mechanism is capable of obtaining higher aggregation efficiency and slot utilization.2.A packet-length-based frame aggregation mechanism is proposed for solving the cost problem of frame aggregation,to reduce the A-MPDU overhead and improve the throughout.Based on the empty delimiter overhead caused by the minimum distance between MPDUs,we design a frame aggregation scheduling algorithm relying on the minimum distance between MPDUs.By analyzing the influence of the frame length on frame aggregation overhead,we choose the adaptive frame aggregation,then decided aggregation threshold based on the minimum distance between MPDUs.We further choose the aggregation mode relying on the length of A-MSDU,and propose an adaptive A-MSDU aggregation scheme based on the analysis of delay in aggregation mechanism.The simulation result shows that our proposed aggregation mechanism has higher and more stable throughout compared with the counterparts both in the error-free and error-prone channels.