Collision Classification Model-Based Collision Resolution Algorithm

Abstract

Traditional backoff algorithms in IEEE 802.11 networks adopt contention window scheme for collision resolution.Collided nodes are redistributed in extended window ranges to avoid further collisions.However,as long as these distribution windows intersect with each other,collision may still occur.To solve this problem,this paper puts forward a collision classification model to classify collisions into cross collision and intra collision and proposes to solve them with different policies.It utilizes sequential discrete window distribution(SDWD) scheme to resolve cross collision by distributing the collided nodes in a series of discrete Elementary Windows and the intra collision is resolved with an appropriate elementary window size to achieve a tradeoff between intra collision probability and packet latency.Based on this proposal,two algorithms are developed featuring cross collision resolution(CCR) and collision-free CCR(CF-CCR).The extensive simulations demonstrate that compared with IEEE 802.11 DCF protocol,the CCR and CF-CCR algorithms consistently excel,in terms of collision rate,throughput,delay,fairness and delay jitter.Moreover,CCR and CF-CCR exhibit their respective advantages in different scenarios.