Hindia Mohammad Nour, Reza Ahmed Wasif, Noordin Kamarul Ariffin
Department of Electrical Engineering, Faculty of Engineering, University of Malaya, 50603 Kuala Lumpur, Malaysia.
ScientificWorldJournal. 2014;2014:246206. doi: 10.1155/2014/246206. Epub 2014 Oct 14.
Nowadays, one of the most important challenges in heterogeneous networks is the connection consistency between the mobile station and the base stations. Furthermore, along the roaming process between the mobile station and the base station, the system performance degrades significantly due to the interferences from neighboring base stations, handovers to inaccurate base station and inappropriate technology selection. In this paper, several algorithms are proposed to improve mobile station performance and seamless mobility across the long-term evolution (LTE) and Worldwide Interoperability for Microwave Access (WiMAX) technologies, along with a minimum number of redundant handovers. Firstly, the enhanced global positioning system (GPS) and the novel received signal strength (RSS) prediction approaches are suggested to predict the target base station accurately. Then, the multiple criteria with two thresholds algorithm is proposed to prioritize the selection between LTE and WiMAX as the target technology. In addition, this study also covers the intercell and cochannel interference reduction by adjusting the frequency reuse ratio 3 (FRR3) to work with LTE and WiMAX. The obtained results demonstrate high next base station prediction efficiency and high accuracy for both horizontal and vertical handovers. Moreover, the received signal strength is kept at levels higher than the threshold, while maintaining low connection cost and delay within acceptable levels. In order to highlight the combination of the proposed algorithms' performance, it is compared with the existing RSS and multiple criteria handover decision algorithms.
如今,异构网络中最重要的挑战之一是移动台与基站之间的连接一致性。此外,在移动台与基站之间的漫游过程中,由于相邻基站的干扰、切换到不准确的基站以及技术选择不当,系统性能会显著下降。本文提出了几种算法,以提高移动台在长期演进(LTE)和全球微波接入互操作性(WiMAX)技术中的性能以及无缝移动性,并减少冗余切换的次数。首先,建议采用增强型全球定位系统(GPS)和新颖的接收信号强度(RSS)预测方法来准确预测目标基站。然后,提出了具有两个阈值的多准则算法,以在LTE和WiMAX之间优先选择目标技术。此外,本研究还通过调整频率复用率3(FRR3)来减少小区间和同信道干扰,使其与LTE和WiMAX协同工作。所得结果表明,对于水平和垂直切换,下一个基站的预测效率高且准确性高。此外,接收信号强度保持在高于阈值的水平,同时将连接成本和延迟保持在可接受的低水平。为了突出所提算法性能的组合,将其与现有的RSS和多准则切换决策算法进行了比较。