(A) handover decision scheme for moving networks in 4G wireless systems

Abstract

Current research in fourth-generation (4G) wireless systems is driven by the need to offer high data rate services such as multimedia and VoIP with high quality-of-service at a reasonably low cost. The concept of relay station (RS) as an intermediate between between the base station (BS) and the user terminal(UT)is an architectural upgrade aiming to enhances the system performance in terms of capacity and coverage. As a complementary technology to the shortcomings of RS, Mobile relay station (MRS) has been introduced to provide a seamless connection service to the users even at high mobility, and thus envisioned to be of much advantage in the development of 4G wireless systems. An MRS, when mounted on top of a moving platform, like a bus or a train, is termed as a moving network. In order to ensure efficient application of these moving networks, both from business and technical standpoints, it is important to strategize when, where and to whom does the MRS serve. The 802.16j Technical Requirements for MRS suggests that for the on-board UTs, MRS handover process is allowed whereas in case of the off-board UTs, it is disallowed. The requirements, however, fall short on the details of how to identify on-board UTs. In this context, we consider the problem of distinguishing between on-board and off-board users in 4G wireless systems using the techniques of cellular systems, without the implementation of any outside technology, like external bill-checking system (e.g., RFID). This problem is further complicated by the recent categorization of MRS into two types by the IEEE 802.16j task group. One is the transparent MRS, which does not transmit preamble and MAP signal information to the user terminal (UT), thus making it impossible for the UT to sense its existence. The other is a high capability non-transparent MRS that generates and send its own preamble and MAP information and thus acts as a base station (BS) to the UT. In this study, we introduce a novel ...