International Journal of Computer Applications (0975 – 8887) Volume 105 – No. 7, November 2014 42 Interactive Multi-Media Applications: Quality of Service Guaranteed under Huge Traffic Jameel Shehu Yalli Department of Electrical and Computer Engineering International Islamic University Malaysia, Kuala Lumpur, Malaysia Suhaimi Bn Abd Latif Department of Electrical and Computer Engineering International Islamic University Malaysia, Kuala Lumpur, Malaysia Sadakatul Bari Department of Electrical and Computer Engineering International Islamic University Malaysia, Kuala Lumpur, Malaysia ABSTRACT The internet has brought about revolution in the telecommunication system. The use of computer applications has changed with easiness and low cost. Interactive Multimedia IMM applications such as Voice over Internet Protocol VOIP and video conferencing are being produced. They offer beneficial services to academicians, officers and other users. But these services suffer from performance degradation in the today’s high speed Wireless Local Area Network WLAN. However, guaranteed Quality of Service QoS remains the bottleneck in the network which becomes a great challenge to improve. This work reviewed many approaches attempted to improve the QoS for these applications. Here we considered mapping a QoS class parameter i.e Quality of Servive Class Identifier-to- Differentiated Services Code Points QCI/DSCP to the upstream and downstream data flowing in the core of the network that improves its overall performance. This is achieved by mapping QCI to DSCP and then mapping again the QCI/DSCP to the IMM traffic. This gives the QoS bearer packets highest priority and a strong signal. The results obtained after simulation in QualNet shows that our proposed mechanism produced better performance of the network in comparison to the default. This is measured in terms of three network performance metrics (average delay, average jitter and throughput). The overall average end-to-end delay is decreased by 34%, while overall average jitter drops by 24% and the throughput rises slightly by 4.6%. Keywords Interactive Multimedia IMM, Voice over Internet Protocol VOIP, Wireless Local Area Network WLAN, Quality of Service QoS, Quality of Service Class Identifier QCI, Differentiated Services Code Points DSCP. 1. INTRODUCTION The so called IMM was accomplished in 1876 when ring down circuit was used. Two devices were connected with a wire and the transmission is one-way. The advancement in wired networks brings about bi-directional transmission, the genesis circuit switched technology. The original communication system was analog infrastructure which incorporates a lot of noise. later on, the digital communication evolve which uses repeaters to amplify the signal after some certain distance and reduce the noise by polishing the signal to its original condition. For example, the old Public Switched Telephone Network (PSTN) samples the voice stream at 8 kHz and transmits the digitized voice at a rate of 64kbps [1]. A satisfactory QoS has been enjoyed by PSTN. This is due to its dedicated circuits to each call with a constant connection between the two nodes until the call is finished. The modern telecommunication applications such as the VOIP are having it difficult to maintain the same QoS like that of PSTN because its architecture integrates the voice, video and data in the same channel, although TCP/IP is being used to overcome such drawbacks. VOIP is now widely accepted telecommunication service that uses internet as the transmission medium. It transmits packets or signals for voice communication. VOIP is now used on PCs, hand phones, PDAs etc. The decrease in the cost of internet also decreases the cost of transmitting voice packets. The primary reason for its growth is its low service cost and support under WiFi, because WiFi doesn’t require any cellular or other networks, and can be use simply on portable devices. However, the quality of the VOIP communication remains a bottleneck for its service. The throughput of the VOIP is practically low compared to its wired counterpart and again Carrier Sense Multiple Access with Collision Avoidance (CSMA/CA) based medium access mechanism used in the Wi-Fi networks wastes a lot of time in collision avoidance thereby causing more delay and leads to voice quality degradation [1]. Video conferencing is also another multi-media application which requires QoS through its transmission and end to end performance. Users often tell their assessment which is so called QoE but it could be biased. But if presented realistically, it can make the designer to improve on his network. Video QoE effects are caused by the QoS problems such as bandwidth, jitter, delay, loss and throughput. Customers often assess the network based on cost, availability, reliability, usability, and fidelity [1]. Quality of Service (QoS) is an important parameter to be dealt with in any networking and communication system. It has been implemented in the old Public Switched Telephone Network (PSTN) where it is guaranteed because of the dedicated circuit to each call. It is also implemented in the Next Generations Network (NGN) where it is not guaranteed because single circuits are not dedicated to single calls and resources are been shared among users. Many researchers consider the configuration of QoS at layer 3 and the extension to layer 2. However, it is very essential to ensure better QoS for the efficiency of these communicating networks.