A Study of Handover Strategy for Cellular Network with Femtocells

• Main Authors: Ching-jung Teng, 鄧靜容
• Other Authors: Jieh-chian Wu
• Format: Others
• Language: zh-TW
• Published: 2013
• Online Access: http://ndltd.ncl.edu.tw/handle/26769784128819263909

碩士 === 國立高雄第一科技大學 === 電腦與通訊工程研究所 === 101 === 3GPP Long Term Evolution (LTE) defines a high speed wireless communication standard for mobile phones and data terminals. Handover strategy is considered as one of the crucial topics in high-speed mobility-supported wireless communication systems. In the macrocell and femtocell coexisting system, the high speed movement of user equipment may often cause unnecessary handovers. Therefore, an efficient handover strategy is necessary to avoid unnecessary handovers. The parameter used in conventional handover strategy is signal strength. Some proposed handover strategy considered not only signal strength, but also mobility of user equipment, real time service, and access mode of user equipment to reduce unnecessary handovers. In addition, some study proposed SINR (Signal to Interference and Noise Ratio) instead of signal strength to improve femtocell utilization. In this thesis, we analyze these handover strategies and propose a new one. Our simulation result shows that our proposed handover strategy, in comparison with conventional strategy, can reduce the ratio of unnecessary handover by 84%. In addition, we observe that the movement of user equipment does not dependent on the distribution of the base station. However, different distribution of base stations will result in different occurrence of handovers. Suppose we are able to choose the path with less number of handovers, the radio resource can be well conserved and better quality of service can be provided to users. Our simulation result shows that the path selection strategy can reduce the number of unnecessary handovers by 80% in comparison with random walk strategy.