Distributed media access control protocol for increasing capacity of wireless local area network

Abstract

The invention discloses a distributed media access control protocol, in particular to a proxy polling mixed access protocol for increasing the capacity of a wireless local area network. The invention designs an access strategy based on polling to avoid channel conflicts, namely, according to a partial schedule strategy designed by the protocol, the existing transmission traffic flow substitutes an AP to select next transmission traffic flow, which leads the traffic flow in a network to be transmitted in sequence in a relay way. Meanwhile, the protocol adopts an access strategy based on competition as supplement to solve problems arising when a polling decision is wrong. The partial schedule strategy of the invention provides a service differentiating system based on conditions, which promotes the fairness of services with low priority when network load is relatively low. On the basis of a strategy for forecasting queue information, the partial schedule strategy further adopts a periodic polling strategy as supplement to modify wrong polling decisions on time, so as to adapt to service arrival models. The protocol remarkably increases the capacity of networks and has good performance.

Description

technical field [0001] The invention relates to a medium access control (MAC) protocol in a wireless local area network (WLAN), in particular to a distributed access method in a single-hop WLAN network without infrastructure. technical background [0002] In traditional protocols, in a network without infrastructure, only contention-based access strategies can be used, while polling-based access strategies can only be used in networks with infrastructure. The IEEE 802.11(e) standard is widely used in WLAN networks. 802.11 defines a contention-based distributed coordination function (DCF) and a poll-based point coordination function (PCF). DCF can be used in an environment without an access point (AP), and nodes compete for channels through a carrier sense multiple access / collision avoidance (CSMA / CA) mechanism. When a station has a frame to send, it first listens to the channel, and if the channel is idle for continuous DCF Interframe Space (DIFS), it sends directly. Afte...

AI Technical Summary

Problems solved by technology

Although EDCA improves the quality of service (QoS) performance of real-time services to a certain extent through the mechanism of service differentiation, this competition mode inevitably causes serious conflicts under high service loads, thereby limiting network capacity and reducing Service QoS performance

The non-competition feature of PCF and HCCA protocols can solve this problem well, but it cannot be used in a distributed environment without APs

Moreover, because the scheduling-based polling algorithm cannot accurately predict the queue status of the polled node, it will cause unnecessary overhead when the polled station has no frames to send, but the contention-based protocol does not have this problem

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