Analysis on Staleness-Aware Mechanisms of Real-Time Transport Protocols in WPANs

Supporting real-time data transport in highly dynamic conditions, which arise in wireless and mobile ad hoc networks is challenging. The significant variations in link bandwidth and latency undermine the quality of real-time applications by introducing congestion and delay jitters. For such applications data is only useful before its lifetime expires. In this paper we investigate a staleness-aware mechanism for realtime multimedia flows, where the system can decide if the respective frame is eligible or not for transmission, namely, if it can be entirely transmitted before its lifetime expires. A mathematical model and analysis is presented, where the partial and complete frame discarding staleness-aware techniques are compared. Then the Burst Transfer Eligibility Decision (BTED) mechanism, a concrete staleness-aware solution for WPANs is introduced. In order to have a deeper understanding of staleness-aware mechanisms, simulation analysis is also presented. We show that complete frame discarding presents better results than the partial rejection in terms of several performance metrics.