Cross-Layer Modeling of Dynamic Service Addition Performance in IEEE 802.16 Networks

The IEEE 802.16 standard enables high transmission rates and supports mobility and quality of service (QoS) in cellular networks. To achieve such objectives, multicarrier transmission based on orthogonal frequency-division multiplexing (OFDM) is used and is combined with a connection-oriented approach at the medium access control (MAC) layer. Such connections, or service flows, are dynamically established using a three-way handshake protocol called the Dynamic Service Addition (DSA) protocol. This paper proposes an analytical model to analyze the performance of the DSA protocol in terms of signaling blocking, admission control blocking, and latency in an IEEE 802.16 network. The analytical model based on queueing theory is combined with the quality estimation of the OFDM-based physical layer, using a cross-layer approach. Two mobile radio channels have been considered to validate the analytical model: a block flat-fading channel and a time-varying frequency-selective fading channel in the presence of mobility at different speeds. The analytical model closely matches the results obtained by computer simulations for both types of radio channels. The impact of mobility on the DSA performance is assessed under various settings of DSA parameters and mobile station (MS) speeds. The results highlight the different impacts of DSA parameters on the various performance metrics. Such an evaluation is fundamental for optimally selecting the DSA parameters while taking into account the channel quality. In addition, this paper shows the need for the management of the service flows activated without knowledge of the involved MS, particularly in the case of high error rates.