Persistent resource allocations for VoIP traffic in packet-switching mobile cellular networks

It is expected that future IMT-Advanced systems will operate packet-switched due to the dominance of data services. However, it is inherent to packet-switched systems to not cope well with voice services as periodic resource usage patterns are not signalled efficiently. In this paper, we present a simple technique to reduce the signalling overhead for resource allocations especially for voice-over-IP (VoIP) traffic thus increasing the VoIP capacity of the system, considerably. The proposed technique assigns persistent resource allocation (PRA) per VoIP connection that are valid for a fix number of frames. Resource allocations for succeeding frames have to be signalled by new PRAs. This supersedes any procedures for deallocation of PRAs and associated error handling. Within our work we introduce an analytical model to evaluate the possible VoIP capacity gains. Additionally, we show results of event-driven simulations to validate the analysis. The PRA technique is applicable to all packet-switched systems. We show exemplary results for the WiMAX system. In this paper, we present a simple technique called persistent resource allocation (PRA) to reduce the signalling overhead in packet-switching mobile radio networks, especially for VoIP traffic. The figure shows our idea: resource allocations for mobile station (MS) 42 are signalled in frame n (solid lines) and remain valid in frame up to frame (dashed lines). The parameter k matches the period length of packet arrival in number of frames and m limits the life time (time-to-live) of the PRA. Copyright © 2010 John Wiley & Sons, Ltd.