A Dynamic Resource Allocation Scheme for the Downlink Heterogeneous Traffic of Internet Protocol (IP) Based OFDM networks

Abstract

Radio Resource management mechanisms such as physical-centric radio resource allocation and medium access control (MAC)—centric packet scheduling are expected to play a substantial role in the performance of orthogonal frequency division multiplexing (OFDM) based wireless networks. OFDM provide fine granularity for resource allocation since they are capable of dynamically assigning sub-carriers to multiple users and adaptively allocating transmit power. The current layered networking architecture, in which each layer is designed and operated independently, results in inefficient resource use in wireless networks due to the nature of the wireless medium, such as time-varying channel fading. Thus, we need an integrated adaptive design across different layers, allowing for a cross-layer design. In this paper, a scheduling scheme is proposed to dynamically allocate resources for the downlink data transmission of internet protocol based OFDM networks. Generally to maximize the capacity and user satisfaction improvements in packet data admission, scheduling and policing are necessary. Of the three, efficient scheduling has the greatest impact on increased system capacity or effective spectrum usage. In addition, proper scheduling can greatly improve user satisfaction. The contribution of this work is twofold: first we evaluate current allocation schemes by exploiting the knowledge of channel sate information (CSI) and traffic characteristics in terms of queue state information (QSI) to acquire the system performance on a real time network. Second, the resource allocation scheme is extended by incorporating MAC layer information as well as opportunistic packet scheduling in the time-domain-based on minimum weight cost function. The key factors that affect the overall system performance in terms of system average throughput and delay are identified, evaluated and discussed.