A study for movable boundary mechanism in TDMA/TDD wireless MAN

Abstract

This thesis presents movable boundary mechanism for real time streaming service and non-real time service in TDMA/TDD wireless MAN. Recently the demand for wider bandwidth in wireless environment has been increasing rapidly. In FDD systems, the uplink channel is assigned the same amount of bandwidth as the paired downlink channel in order to support this type of symmetrical uplink and downlink traffic. Conversely, for data services, often the up and downlink traffics are asymmetric and dynamically variable in volume. FDD is not flexible enough for this type of dynamic up and downlink traffic. TDD is completely different, in that only one radio frequency carrier is used for both uplink and downlink transmissions. TDD operation can be further divided into two modes: static TDD (S-TDD) and dynamic TDD (D-TDD). In S-TDD operation, a portion of each frame is allocated for downlink transmissions. Both of FDD and S-TDD have the problem which is the waste of radio frequency resource according to assigning time slots in order to provide multimedia service. So, a variety of the time slot assignment algorithms are proposed in order to reduce the waste of radio frequency resource and enhance a usage of bandwidth. But, there is not this algorithm in wireless MAN. And the movable boundary mechanism proposed for integrated voice and data service in telecommunication network. In this paper, we propose movable boundary mechanism for real time streaming service by applying this mechanism. It can reduce the time delay and enhance the performance in TDMA with TDD.