Introduction

Wireless networking has been a vibrant research area over the last two decades. During this time, we have observed the evolution of a number of different wireless communications standards that support a wide range of services. They include delay-sensitive applications such as voice and real-time video that usually have strict requirements with respect to quality of service (Q_oS) parameters such as data rate, delay and/or bit error rate. In such cases, a network designer must ensure that the Q_oS requirements are satisfied permanently. Data applications, however, may have fundamentally different Q_oS requirements and traffic characteristics than video or voice applications. In fact, most data applications are delay-insensitive, and therefore may tolerate larger transmission delays.