Bandwidth allocation in multi-services access networks using statistical traffic models

The appearance of increased-bandwidth applications with quality-of-service (QoS) requirements has brought about the emergence of multi-service access networks. In these networks service is provided to user applications according to their QoS requirements. A very important aspect is that of resource (bandwidth) management. A careful management of resources is needed in order to accommodate a large amount of users and still be able to comply with the demanded QoS. Our study proposes a versatile centralized bandwidth allocation scheme for the return path of access networks. It is versatile in the sense that it works with several physical media, and the multiple-access schemes. The proposed scheme takes advantage of the statistical characteristics of the traffic generated by the applications being serviced in order to minimize the bandwidth dedicated to control signals (bandwidth reservation) in the return path. This is done with the purpose of achieving high bandwidth utilization. At the same time, the proposed approach complies with the QoS requirements of the serviced applications. As part of our work, we also propose a procedure to obtain a statistical model of the traffic generated by an application. We use this procedure to obtain a statistical model for a very popular application: Internet video game. The traffic generated by several video game applications was studied and the resulting traffic model is presented. The performance of our bandwidth allocation approach was evaluated using computer simulation in a DOCSIS-based cable network environment, as well as in a cdma2000 network. The metrics used to evaluate performance are the average packet delay, outage probability (for cdma2000 systems only), data throughput, and number of users supported. Results are obtained for networks with a single service, as well as for a mixed service scenario. In the former case all users are assumed to be using real-time applications. In the latter case users with real time and delay tolerant applications are serviced simultaneously. As shown by the results, our approach achieves high bandwidth utilization, and still complies with the delay constraints and outage constraints (in cdma2000 networks) imposed by the user applications. This compliance comes at the detriment of delay tolerant application. In both environments (DOCSIS and cdma2000) it increases the system capacity as compared to reference approaches.