Addressing Slot Drift in Decentralized Collision Free Access Schemes for WLANs
Decentralized Collision-Free Access (DCFA) schemes are an appealing family of MAC mechanisms in WLANs due to their good system throughput and decentralized nature. In this paper we consider the problem of slot drift for these schemes and provide evidence that DCFA can be vulnerable to such problems. We propose two schemes to enhance DCFA in this regard: Global View Synchronization (GVS) and Smart Collision Free (SCF). GVS aims to provide slot indexing, which helps stations correct their counters after drift. SCF accelerates the convergence process to the collision-free state for WLANs, and so reduces the impact of drift. Simulation results show that both GVS and SCF improve the system performance in the presence of slot drift.
KeywordsWLAN Decentralization collision-free MACs slot drift
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