Adaptive QoS for Mobile Multimedia Services over Wireless Networks

Absfrucf-A wireless network that provides multimedia services should control the quality of the transmission link for users, allocating resources according to the service type of each user, be it voice, video, image or data. This paper proposes a scheme to allocate the desired signal to interference noise ratio (SINR) for those users with mul- timedia services by exploiting power control and smart antennas, while not affecting users with voice service. A method to quickly initialize new users into such a network is also proposed. I. INTRODUCTION Wireless network technology has advanced prodigiously to the point where we can now talk of providing multimedia services to mobile telephony users. A wireless network with integrated multimedia ser- vices, requires that each user should have a different channel quality to accommodate different service types, say voice, video conferencing, email, etc. The SINR levels, however are strongly related to automatic power control and smart antenna results. Using these tools, we pro- pose to control the levels of SINR that each user is afforded, and this selection is done according to the individual need of each user, and the quality of channels that the mobile system can allow, given the interfer- ence present at any given time. We address two problems associated to this subject: the first is how to accommodate the service requirements for each user, given that each multimedia service type has a target SINR level, and the second is how to hasten the system processor through the necessary calculations to quickly provide the multimedia service to each user. The latter point arises when the system is initiating service for a new user, whether the new user is initiating a call or if it is handing off from another base sta- tion. During this process, the system must calculate the power vector for all cochannel mobile users, and the antenna weights for all the as- sociated base stations. These values can be obtained through iterative algorithms that require certain constraints for convergence, but these constraints may be lengthy to verify. In a practical situation, an exten- sive delay before activating the new users is not allowable. We present a technique which reduces the activation latency time for new multi- media service users. For this, we propose a fast and coarse method