Cross Layer Radio Resource Allocation for Multi Carrier Air Interfaces, in Multi-Cell Multi-User Environments

Packet scheduling over shared channels is one of the most attractive issues for researchers dealing with radio resource allocation in wireless networks, as in modern systems different traffic types, with different application requirements, need to co-exist over the air interface. Recently, researchers’ attention has been attracted by multi carrier techniques, and the application of cross-layer approaches to the design of wireless systems. In this work, a radio access network using a multi carrier air interface is considered in a multicell multi-user context. We propose a new cross-layer scheduling algorithm which manages channel, physical layer and application related information; we compare its performance to a previously published cross-layer strategy and to simpler well-known channel aware or unaware techniques, and discuss its optimization. We investigate the performance in terms of perceived user quality and fairness in the presence of mixed realistic traffic composed of H.264 video streaming with tight bounds on the delay jitter, and FTP data. To support video traffic, application-suited buffer management techniques are also considered in conjunction with scheduling, and link adaptation is implemented at physical layer to better exploit channel fluctuations. The role of scheduling and resource allocation functionalities are discussed. It is shown that the cross-layer strategy proposed guarantees the same performance obtained by the previously published algorithm while reducing complexity. Moreover, under heavy loaded conditions, the cross-layer scheduling strategy provides a significant gain with respect to simple channel aware or even unaware techniques.