Performance of Adaptive Bandwidth Allocation for Multimedia Handover Services in UMTS mobile Cellular Networks

Abstract

With the ever growing multimedia services in the telecommunication industry, Quality of Service (QoS) provisioning in cellular networks is becoming more challenging. Studies have suggested that QoS requirements can be met by increasing network capacity through adopting micro/pico/femto-cellular architectures. A consequence of using small cell sizes is the increased rate of call handovers as mobile terminals move between cells. In a network supporting multimedia services, the increased rate of call handovers not only increases the signalling load on the network, but also adversely affects the QoS through sky rocketing handover failures. For seamless connection, one of the solutions will be adequate provision of resources like bandwidth. Moreover, bandwidth being a scarce resource, it should be used efficiently.As the world migrates from Asynchronous Transfer Mode (ATM) transport to Internet Protocol (IP) in UMTS Radio Access Networks (UTRAN), it will introduce more challenges in assigning bandwidth to multimedia services. This is true as IP is of best effort nature. A better solution will be to allocate bandwidth discriminatingly, that is, high priority traffic gets better service while low priority traffic gets reduced service. This paper presents the design, implementation and performance of an Adaptive Bandwidth Allocation scheme for Multimedia Handover Services on an IP-based Radio Access Network of a UMTS Cellular Networks. The methodology adopted is classifying multimedia traffic into different classes using differentiated service (DiffServ) scheme. This is then tested and validated through simulation in Network Simulator 2(NS-2).From the simulation results it has been proven that the adaptive bandwidth allocation minimizes packet losses and give high throughput than non- adaptive bandwidth allocation. It has also been observed that non- adaptive bandwidth allocation does not guarantee service when the network experience congestion due to increased traffic in a cell during handover. After comparing the simulated results, its clear that adaptive bandwidth allocation is found to yield better performance than non- adaptive bandwidth allocation.