Optimal rate and power allocation under quality-of-service requirements for wireless multihop networks

In wireless networks, real-time applications have strict QoS requirements for packet delay, packet loss, and reliability. However, most existing work has not considered these QoS metrics when allocating wireless resources so that the QoS requirements of real-time applications may not be satisfied. To overcome this shortcoming, a rate and power allocation framework incorporating these QoS metrics is first proposed for slow-fading systems. Second, two distributed algorithms are developed to solve this optimization framework although it is nonconvex and nonseparable. Third, an improved framework is proposed to deal with the rate and power allocation with QoS requirements for fast-fading systems. It is shown that the fast-fading state of the network does not need to be considered in this improved framework, and it can be solved using algorithms that are similar to those for the framework of slow-fading systems. In the end, simulations show that our algorithms converge closely to the globally optimal solution. By comparison with an existing model, simulations also verify the validity of our frameworks on dealing with the rate and power allocation with QoS requirements. Copyright (C) 2012 John Wiley & Sons, Ltd.