Adaptive QoS for mobile multimedia services over wireless networks

Abstract

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 multimedia 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.

Rate control for DS-CDMA channels using power control and short orthogonal pseudo random codes

“…Due to the nature of multimedia data, we can assign higher SINR intervals to substreams that require higher rates and lower SINR intervals to those which require lower rates (such as a video substream as opposed to an audio substream). We have shown that the optimization problem: is NP-hard [7]. The part that makes this problem intractable is the second line of (9), which is the test for feasibility of r.…”

“…If the number of antenna elements, D, in the antenna arrays is large enough so that we can assume that the effect of S I k , J ( -) in ( 3 ) can be neglected, then the signal to noise ratio for the ith substream of user k , is [7] (1 For simplicity, assume we use PSK, then the probability of bit error conditioned on the SINR is P r ( e r r o r 1 y k ) = Q ( e ) , which we shall denote p e , k . Here, Q(z) = & J e T d t .…”

“…We define a cost function, (7), that depends on the effective SINR levels and the chosen set of substreams for each user.…”

“…We use a steepest descent method to find a suboptimal solution for the total SINR assignment for each user, [7], [9]. Once we have each users' SINR allotment, 7 , we can optimally choose how many substreams to assign to each user, and what transmission power should be used for each substream.…”

Adaptive QoS for wireless multimedia networks using power control and smart antennas

“…There has been considerable attention devoted to this subject, where the term QoS has been used as an epithet for a variety of quality measures, such as packet dropping rate [1], [2], bit-error rate [3], resolution or quantization scale [4], packet delay [1], [5], and [6], bandwidth [3], [6], and [7], or channel quality or signal-to-interference and noise ratio (SINR) [8]. In this paper, the performance index will be the SINR levels [9], [10].…”