Multimedia Task Scheduling on OLSR enabled Ad hoc Networks Adeel Akram, Shahbaz Pervez, Shoab. A. Khan University of Engineering and Technology Taxila, Pakistan http://www.uettaxila.edu.pk Abstract: - In this paper we present a consolidated scheduling and routing solution to the multimedia ad hoc network problem. We consider a generic ad hoc network with all kinds of heterogeneous devices. These devices are known to have different capabilities and capacities in terms of system resources and network connection speeds. We propose a task partitioning and scheduling mechanism which results in distribution of N tasks with various real-time constraints and work loads on M heterogeneous devices.It has been shown that in case of M=1 an optimal solution to task scheduling can be obtained with computational complexity O(N) however for M≥2 the scheduling algorithm can be demonstrated to be NP-hard by reducing it to the well known NP-Complete bin-packing problem The mechanism proposed in this paper considers device capabilities, Link capacities and task constraints to find a near optimal solution to the multimedia scheduling problem in Ad hoc networks. Key-Words: - Multimedia, Task Partitioning, Real-time constrained task scheduling 1. Introduction Ad hoc wireless networks have been a topic of research for more than a decade now. Most of the research was done on using Ad hoc networks in areas such as disaster recovery, military assignments and scenarios where rapid deployment of networks is required in the absence of conventional infrastructure based network. The focus was to provide communication setup as a temporary measure in areas where deployment of conventional network was not feasible. With the passage of time, phenomenal improvements have been made in maximizing the computing power of devices and performance of communication networks. This technological advancement poses a greater challenge to the researchers to provide services on Ad hoc networks that are available on infrastructure based networks. With increase in the use of Mobile devices such as cellular phones, PDAs, Laptops etc. in our daily lives, the requirement of providing same levels of services on all kinds of devices must be addressed. Multimedia transmission is one such application that requires computational resources as well as network bandwidth to provide information rich contents to the receiving nodes in real-time. Digital Multimedia transmission over Ad hoc network requires encoding of source media in such a format that is resilient to the intermittent jitters in transmission due to route changes or link failures. Moreover as the intermediate nodes in an Ad hoc network act as repeaters to forward multimedia packets towards the destination nodes, the probability of failure increases with the increase in the number of intermediate nodes. Furthermore, the insertion and removal of nodes in an Ad hoc network at any given time is a known problem of probability. Multimedia scheduling requires selection of devices based on their computational abilities as well as their possession of network bandwidths while reducing the number of intermediate nodes in a chain of communication. This paper further extends the notion of a wireless cooperative system, which involves migration and execution of tasks on two or more heterogeneous computing devices. Recent advances in wireless communication architectures and computation offloading platforms have made it possible to build such a cooperative environment on the fly and to let resource-limited devices make use of nearby resources for processing and communication. This technique not only has a potential for performance improvement (especially if the processing capability Proceedings of the 5th WSEAS Int. Conf. on Electronics, Hardware, Wireless and Optical Communications, Madrid, Spain, February 15-17, 2006 (pp40-44)