Design and analysis of a VoIP based IEEE 802.16e system

Real-time packet based services such as Voice over IP (VoIP) have stringent packet delivery requirements, characterized by very low packet loss (in the order of 1% – 2%) and tight air-interface delay budgets in the order of tens of milliseconds (ms). In the context of IEEE 802.16e, VoIP service raises additional challenges since the MAP overhead, and hence the required resources dedicated to the control traffic, can grow very large in the presence of multiple simultaneous connections, limiting the amount of resources that can be devoted to the effective traffic. The paper offers a detailed understanding of the specifics of the VoIP application in the IEEE 802.16e (mobile WiMAX) context, including an overview of various design choices, implementation challenges and performance analysis. VoIP capacity results are presented for a set of scenarios accounting in the downlink direction.