高速铁路网络环境下掉话率分析

摘要

在不考虑多普勒频移对网络掉话率影响的前提下，分析高速铁路网络环境下由于越区切换引起的网络掉话率．从高铁网络的越区切换研究出发，得出不同位置的越区切换概率，获得不同位置的掉话概率，提出掉话分析模型．通过对高铁GSM‐R和LTE‐R网络进行掉话率对比仿真发现，LTE‐R网络的掉话率比GSM‐R网络减小了约29．23％；通过对不同列车穿透损耗下的掉话率进行对比仿真发现，穿透损耗越大，掉话率越高，24dB的穿透损耗下掉话率达到0．8％；通过对不同运行速度下的网络掉话率对比仿真发现，列车运行速度越高，网络掉话率越高，LTE‐R网络下540km／h相比60km／h的掉话率提高了151．56％；通过对基站故障情况下的网络掉话进行仿真发现，基站正常时的平均掉话率仅为基站故障后平均掉话率的36．3％．%The dropped‐call probability caused by handoff in high speed network environment was analyzed without considering the impact of Doppler effects on dropped‐call probability .Starting from the study of handoff in high speed netw ork , the handoff probability in different positions w as deduced , and the dropped‐call probability in different positions w as gained to propose a model of dropped‐call probability analysis .The dropped‐call probability in GSM‐R and LTE‐R was simulated . The average dropped‐call probability in LTE‐R is about 29 .23% lower than GSM‐R .The dropped‐call probability with different train through loss was simulated . The larger the train through loss is , the higher the dropped‐call probability is .The average dropped‐call probability can rise to 0 .8% when train through loss is 24 dB . The dropped‐call probability with different train speed was simulated .The faster the train speed is ,the higher the dropped‐call probability is .The average dropped‐call probability with the speed of 540 km/h is 151 .56% higher than the speed of 60 km/h . The dropped‐call probability with fault base station was simulated .The average dropped‐call probability with normal base station is just 36 .3% of the condition with a fault base station .