The evolution of Inter-Working between eHRPD and LTE
24 June 2013
The Enhanced High-Rate Packet Data (eHRPD) system was developed to permit seamless mobility between Third Generation (3G) HRPD and Fourth Generation (4G) Long Term Evolution (LTE) cellular networks. The resulting network architecture is capable of supporting different modes of coupling between the two systems with different levels of optimization in terms of service interruption time and latency. We trace the evolution of the eHRPD system in 3GPP2 and summarize its key attributes that have made it attractive for deployment by network operators. Operators maintaining this integrated eHRPD-LTE network are also looking to maximize the utilization of air-interface resources dedicated to either technology. We describe and analyze a family of possible techniques for effective load balancing between eHRPD and LTE as a further augmentation of the eHRPD-LTE network.