Broadcast traffic queueing in OFDMA systems for spectrum efficiency and improved QoS provisioning

A queueing model is proposed for multiuser systems for increased spectrum efficiency and better QoS provisioning. Broadcast services are quickly finding their way in to the IP domain and service providers need to introduce different traffic servicing models to handle these bandwidth intensive multimedia services. In an Orthogonal-frequency-division-multiple-access system, using conventional subcarrier per-user resource allocation method is inefficient. Here we present a two-stage queueing model where broadcast streaming traffic are aggregated by separate queues and processed in batches in the first-stage before propagating to the root queue. Modeling the general user traffic as an exogenous traffic source is also considered, which provides more delay performance improvement. The queueing framework is mathematically analyzed for average delay performances. Simulation results validate that not only resource consumption is reduced, but system queue delays also show substantial reductions. The introduced queueing model provides a framework for handling broadcast traffic and to reduce its impact on total system throughput.