MMAODV: A REACTIVE ROUTING PROTOCOL FOR MULTIMEDIA AD HOC NETWORKS Wazir Zada Khan 2 , Adeel Akram 1 , Dr. Aman Ullah Khan 2 , Dr. Shoab A. Khan 1 1 Faculty of Telecommunication and Information Engineering, University of Engineering and Technology, Taxila, Punjab, Pakistan, 2 Comsats Institute of Information Technology, Wah, Pakistan wazirzadakhan@yahoo.com , adeel@uettaxila.edu.pk , auk_khan@yahoo.com , shoab@uettaxila.edu.pk ABSTRACT In this paper we present (MMAODV); a reactive routing protocol for Multimedia ad hoc network applications. This protocol is an extension to the standard AODV protocol. In order to support multimedia applications we propose a mechanism for route discovery using AODV control messages with some changes. Multimedia applications require selection of devices based on their computational abilities, network bandwidths, memory, availability and delay etc during Route discovery process. A parameter matrix is incorporated in control messages (i.e. RREQ and RREP). Each parameter of this matrix in a control message is compared with local resources available on all receiving nodes. If the receiving node meets the requirements of the parameter matrix, it is considered to be capable for multimedia application. This node is selected for participation in routing from source to the destination. We introduce an enhancement from standard AODV on the bases of parameter matrix, i.e. if a node is not capable for multimedia application then that node will drop RREQ message and will not broadcast it again contrary to the standard AODV protocol. Keywords: Multimedia, Reactive Routing, AODV Extension, MMAODV Routing Protocol. I. INTRODUCTION Ad hoc networks are mostly used in scenarios where no conventional infrastructure based network exists, e.g. Search & Rescue Missions, Automated Battlefield, Remote Areas, and Outdoor Conferences/Meetings, etc. The basic aim of ad hoc networks was to provide communication setup as a temporary measure in areas where deployment of conventional network was not feasible. With rapid development in the field of communication networks and technology, communication networks and devices have got more processing power and higher performance. These improvements bring new challenges and demand all services on Ad hoc networks that were previously available on infrastructure-based networks only. Mobile devices such as cellular phones, PDAs, Laptops are becoming essential part of our daily lives, the requirement of providing same levels of services on all kinds of devices must be addressed. But in real life all the devices in ad hoc network are heterogeneous and these devices are known to have different capabilities and capacities in terms of system resources and network connection speeds. Problems occur when we deal with real-time multimedia applications using ad hoc protocols (e.g. AODV, DSDV and DSR) that are not suitable [7] for multimedia applications and communication in the area of mobile Ad-hoc networks as well. Conventional routing protocols for mobile ad hoc networks were designed to provide basic connectivity between the communicating devices. These protocols were not created keeping multimedia applications in mind. So in order to support Multimedia applications over such protocols, it is necessary to introduce some additions to the existing protocols. AODV is one such protocol that has been in use under standard ad hoc networks. In this paper, we propose and extension to the standard AODV protocol to support multimedia applications in mobile ad hoc networks. The selection of appropriate devices for multimedia routing is very important. This selection is based upon the capability of each device, to perform routing of multimedia streams. In our extension to existing AODV protocol, for multimedia enabled ad hoc networks, no additional control traffic is generated (only augmented RREQ and RREP messages). II. AODV OVERVIEW Ad hoc on Demand Distance Vector Routing Protocol (AODV) [1, 2] is an on demand routing protocol that establishes a route on if and when required bases to reduce traffic overhead. (AODV) is reactive protocol with loop free routes even while repairing broken links. AODV was derive from DSDV [3] and DSR [8]. In Distance Vector Routing each node knows its neighbors and the costs to reach them. AODV uses, many types of control messages (i.e. RREQ, RREP, and RERR etc) for routing. When a node S (Source) wants to send its data to a node D (Destination) and node S has no direct route to D then it broadcasts a route request message (RREQ) to all its neighbors. On reception of RREQ message the recipient node checks the destination IP address. If the recipient node is the destination node or has a direct path to destination then it will send a RREP message to S otherwise it broadcasts a RREQ message to all its neighbors after adding some additional information into RREQ message. When a node receives RREP message it creates a forward path to