Gauging the Scalability of SLIM+ Multicast Routing Protocol for Live Multimedia Streaming in MANETs

To propose and develop a multicast routing protocol for MANETs it is a challenge for a researcher to implement all possible characteristics of a multicast routing protocol to make it well performed. One of the major problem to cope with, is its scalability. It means if the number of nodes increases then the protocol should not intensely affected regarding the performance. For the transmission of live multimedia streaming or one-to-many type multicast applications in open-MANETs (any number of interested nodes which are in the transmission range may join in the network) a scalable multicast routing protocol is still in need by the researchers. SLIM+ (Advanced-Simple Lightweight Intuitive Multicast) which has a tree based distribution structure is introduced as a protocol to perform in open-MANETs for these type of multicast applications. SLIM+ ensures an advertisement mechanism that is much needed feature in open-MANETs (Vehicular Ad-Hoc Networks/VANETS and Local area social Networks). In this paper we gauged the scalability of SLIM+ protocol by comparing it with another popular tree based multicast routing protocol MAODV (Multicast Ad-hoc on-demand Distance Vector) with respect to its Packet Delivery Ratio (PDR) in a mobility scenario. The results clearly shows that SLIM+ routing protocol is indeed a scalable multicast protocol that performs well even in highly stressed scenarios where other protocol collapse. On increasing the number of simultaneous listener nodes and also varying the number of join/leave sessions per node as stress, the PDR of SLIM+ remained stable and successful. To gauge the scalability by increasing the number of nodes, SLIM+ out performed in delivering of packets where as the most renowned MAODV get affected and showed failure in successful delivering of packets (PDR).