Sip In Ad Hoc Networks Implementation And Study

An emerging paradigm in communication networks promises to provide ubiquity services in our daily lives, that is, to obtain any service, anywhere and anytime. The development of current wireless technologies, such as 3G and future 4G, will allow mobile users to obtain services and multimedia information with reliability and efficiency. Nevertheless, to achieve true ubiquity, services have to be provided in zones where the current wireless cellular infrastructure is not present or is not economically possible. Ad Hoc network emerges as the solution to these cases. So how to provide the multimedia applications in Ad Hoc network becomes so important, however, the common denominator of such application is that they all require the establishment of session before the actual data flow can begin. SIP provided by IETF is a session management protocol in order to support applications such as VoIP, Instant Message etc, it also chosen as the signaling protocol in the 3GPP framework. However, SIP relies on infrastructure such as Proxy Server, DNS Server, which is unavailable in Ad Hoc network.This thesis first presents a fully distributed SIP (fdSIP) approach in Ad Hoc network, fdSIP means that the basic operations of retrieving user contact information are performed using SIP method, which is done by embedding the basic functionalities of SIP proxy and registrar server in every mobile node forming Ad Hoc network. However, fdSIP has two limitations: first it requires the exchange of a large amount of short packets in a limited bandwidth environment; and second it is based on broadcast, so it may not be scalable to networks with large number of nodes. So on the basis of fdSIP method, this thesis adopts the idea of cross-layer design, which combines the characteristics of SIP with the particular Ad Hoc routing protocol, and propose two different mechanisms: SIP-AODV and SIP-ZRP. The SIP-AODV approach based on the AODV routing protocol combines the SIP REGISTER with HELLO message of AODV, which reduces the number of transmitted messages and therefore improve bandwidth use and decrease the collision probability. However, it does not resolve the scalability issue due to the fact that is still based on broadcast. So, the another approach SIP-ZRP mechanism which is based on the ZRP routing protocol combines the SIP REGISTER with packet delivery protocol BRP of ZRP can improve the scalability of the network.Simulation results show that SIP-ZRP performs better for static multihop Ad Hoc network than SIP-AODV in terms of the latency in SIP session setup. SIP–AODV, on the other hand, performs better in networks with random node mobility. SIP-ZRP, however, has lower routing overheads and higher call setup success rate.