Application of Heuristic MMKP in Admission Control and QoS Adaptation for Distributed Video on Demand Service Md. Shamsul Alam S.M.Kamrul Hasan A.S.M. Sohail Mahmudul Hasan Boshir Ahmed Department of Computer Science and Engineering Rajshahi University of Engineering & Technology Rajshahi-6204, Bangladesh {shamsulbd, khrajeeb, sohail_ruet, hsagor, boshir_bd}@yahoo.com Abstract Allocation and reservation of resources, such as CPU cycles and I/O bandwidth of multimedia servers and link bandwidth in the network, is essential to ensure Quality of Service (QoS) for multimedia services delivered over the Internet. In this paper, we have proposed a new semi- distributed architecture for admission control and QoS adaptation of multimedia sessions to maximize revenue from multimedia services for Distributed Video on Demand System (DVoDS). We have introduced the mapping of Utility Model - Distributed (UM-D) by semi- distributed controller to the Multidimensional Multiple- choice Knapsack Problem (MMKP), a variant of the classical 0-1 Knapsack Problem. An exact solution of MMKP, an NP-hard problem, is not applicable for the online admission control problem in the VoD System. Therefore we have applied heuristic, I-HEU for solving the MMKP for online real-time admission control and QoS adaptation. We have applied the admission control strategy described in the UM-D to the set of Media Server Farms providing streaming videos to users. The performance of semi-distributed architecture applied in a simulated environment over a set of Media Server Farm has been discussed detail using the experimental outcome. 1. Introduction Recent years have witnessed the use of digital video and audio in several important applications that affect various aspects of our daily life. These applications include distance learning, digital libraries, Movie-on-Demand (MoD), electronic commerce, etc. Some applications, such as video conferencing or streaming audio, video on demand, produce network traffic, which require a guaranteed level of Quality-of-Service (QoS) to work properly. These QoS requirements may be in terms of a minimum bandwidth, bounded end-to-end delays, or maximum packet loss rate suffered by a flow. To support such flows and to allocate and maintain their finite network resources to uphold their guarantees, some form of admission control is important to accept profitable flows and to reject new traffic flows that would cause the controller to violate its promises. In this paper we have proposed a semi-distributed model of VoD system and semi-distributed controller architecture to do admission control and QoS adaptation for the set of Media Server Farm. We have proposed the mapping of utility model- distributed (UM-D) to the MMKP for the semi-distributed admission controller. Finally, to analyze the performance, we have presented simulation of admission controllers over a set of Media Server Farms. 2. Related Work Guaranteed transmission of voice and video is a challenge of the researchers in Internet computing field. There has been lot of interesting works in recent years on reservation-based management of resources like CPU cycles and bandwidth carrying the video and voice [1, 2, 3]. Transmission of video requires guaranteed Quality of Service (QoS), which is defined by the amount of bandwidth, latency and jitter bound; otherwise the customers will not pay for the services. Delivery of multimedia streams with absolute guaranteed QoS from a single multimedia server has been proposed by Khan [4]. Hua[1] describes video delivery using multicast, streaming strategies with application layer multicast, and proxy caching techniques. To do admission control and QoS adaptation in a set of Media Server Farms, centralized broker architecture has been proposed by Akbar [5]. The load balancing problems of centralized scheme lead us to the development of a fully distributed scheme for MM servers with more scalability and fault tolerance [7]. But, fully distributed architecture faces message passing complexity and time requirement overhead for specific session. Mundur [8] proposed a global request handling and admission control strategies based on limited redirection of blocked requests to other resources for distributed VoD system. Redirect request handling polices require higher implementation overhead and extra connection setup time. The Utility Model- Distributed