Abstract:
With the prevalence of multimedia applications and the potential commercial usage of Mobile
Ad hoc Networks (MANETs) in group communications, Quality of Service (QoS) support
became a key requirement. Recently, some researchers studied QoS multicast issues in
MANETs. Most of the existing QoS multicast routing protocols are designed with flat topology
and small networks in mind. In this paper, we investigate the scalability problem of these routing
protocols. In particular, a Position-Based QoS Multicast Routing Protocol (PBQMRP) has been
developed. PBQMRP builds a source multicast tree guided by the geographic information of the
mobile nodes, which helps in achieving more efficient multicast delivery. This protocol depends
on the location information of the multicast members which is obtained using a location service
algorithm. A virtual backbone structure has been proposed to perform this location service with
minimum overhead and this structure is utilized to provide efficient packet transmissions in a
dynamic mobile Ad hoc network environment. The performance of PBQMRP is evaluated by
performing both quantitative analysis and extensive simulations. The results show that the used
virtual clustering is very useful in improving scalability and outperforms other clustering
schemes. Compared to On-Demand Multicast Routing Protocol (ODMRP), PBQMRP achieves
competing packet delivery ratio and significantly lower control overhead.
