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.
