Bài viết Cải thiện hoạt động của các trạm chuyển tiếp để duy trì kết nối cho các cuộc gọi chuyển giao trong hệ thống 4G LTE bằng kỹ thuật chuyển tiếp kênh mô tả nguyên lý CRS; Phân tích các nội dung về duy trì kết nối cho các cuộc gọi chuyển giao trong 4G LTE áp dụng CRS | Tạp chí Khoa học Giao thông vận tải Tập 73 Số 5 06 2022 526-539 Transport and Communications Science Journal IMPROVING THE OPERATION OF RELAY STATIONS TO MAINTAIN THE CONNECTIONS FOR HANDOVER CALLS IN 4G LTE SYSTEM BY CHANNEL RELAYING STRATEGY Ngo The Anh Tran Huynh Minh Tan Pham Huyen Trang Le Ngoc Thach University of Transport and Communications Campus in Ho Chi Minh City 450 Le Van Viet Thu Duc City Ho Chi Minh City Vietnam ARTICLE INFO TYPE Research Article Received 14 04 2022 Revised 01 06 2022 Accepted 08 06 2022 Published online 15 06 2022 https Corresponding author Email anhnt_ph@ Tel 84 948866699 Abstract. In general Relay Stations RS have been used in the 4G LTE systems to extend the coverage or to improve the wireless links in a certain area of a certain Base Station BS via relaying the information between BS and particular Mobile User MU . This use of RS leads to the use of frequency resource assigned to BS has really not been optimised. Moreover maintaining the radio connection for handover calls in mobile communication systems still remain the challenge to both researchers and services providers. The use of RS to enhance the successful probability for handover calls as well as to utilise efficiency the frequency resource is the interesting topic for researchers. In this paper RS not only helps the BS to expend the coverage but also to exploit capacity maximally for new calls while still satisfy the channel requests for handover calls from MU even from MU using real time data services. Furthermore the use of RS in this paper also provided an additional view to the researchers in term of channel allocation to BS efficiency to optimise the channel utilisation in the system. The simulation results show that when the BS have been assigned 30 frequency channels the use of RS allows to guarantee the probability of handover success is above . Keywords relay station handover quality of service real time data .
