Synchronized RACH-less Handover Solution for LTE Heterogeneous Networks

Some of the most recent LTE features require synchronous base stations, and time-synchronized base stations also offer opportunities for improved handover mechanisms by introducing a new synchronized RACH-less handover scheme. The synchronized RACH-less handover solution offers significant reductions in the data connectivity interruption time at each handover, no need for random access in the target cell, and reduced overall handover execution time. Laboratory handover measurement results, using commercial LTE equipment, are presented and analyzed to justify the latency benefits of the proposed handover solution. Secondly, extensive system level simulation results are presented to further quantify the network level benefits. The results of these performance investigations reveal reduction of the interruption time at every handover from 55 ms (mean) to 5 ms and improvements in the radio link failure probability as a result of faster handover execution.