The Effect of Using P-XCAST Routing Protocol on Many-to-Many Applications

There are two types of wireless networks, infrastructure wireless network and Wireless ad hoc networks. Wireless ad hoc networks are well suited for use by emergency response teams, for search and rescue operations that require team-based communications in the absence of working telecommunications infrastructure, while infrastructure networks require the existence of access point in which all the communications are done through it. Unfortunately, wireless ad hoc networks suffer from limited bandwidth and QoS constraints. A Priority eXplicit multiCAST based routing protocol (P-XCAST) is presented in this paper to support team-based many-to-many communications in wireless ad hoc networks. eXplicit multiCAST (XCAST) is well suited for supporting a large number of small groups effectively, in comparison with multicast based protocols. However, since XCAST was initially designed for wired networks, it was not optimized for wireless ad hoc network use. The proposed P-XCAST protocol enhances XCAST for wireless ad hoc network use by modifying the Route Request mechanism in AODV to build the network topology, and route data packets containing the list of destinations for a given group in the XCAST header, by classifying the destinations according to similarities in their next hop neighbors and hop counts. A single data packet is XCASTed in lieu of sending n Unicast data packets to n destinations with the same next hop neighbor. In addition, P-XCAST is merged with a new mobile group management protocol to handle mobility of group members. In this paper, P-XCAST was tested using topologies with different sources that were sending and receiving data at the same time to handle foreground and background many-to-many applications. The results of simulation experiments show that P-XCAST achieved better QoS performance compared with other routing protocols for small group sizes typical of group communications applications such as Push-To-Talk (PTT)