Evaluating DMM Based Handover Solutions Towards Serving uRLLc in Heterogeneous Networks
摘要
Distributed mobility management (DMM) has emerged as a promising solution to manage mobility in heterogeneous networks consisting of both Long term evolution advanced (LTE-A) and New radio (NR) systems. While switching from one kind of access network to another, satisfying the quality of service requirement for ultra reliable low latency communication (uRLLc) is particularly challenging. This is due to the delay introduced by the handover algorithms operating from Layer 2 (L2) and Layer 3 (L3). Minimum L2 handover latency in NR system is known to be 50 ms, which is higher than the permissible range for uRLLc services. To reduce handover latency, different L2 (e.g., semisoft handover) and L3 (IP Preregistration) enhancements have been proposed. However, performance analysis of DMM protocol in conjunction with these enhancements is quiet limited in the existing literature. Moreover the existing works on DMM do not focus on the delay and reliability requirements of uRLLc applications. In this work, through analysis and simulation, effectiveness of different DMM based handover solutions in minimizing handover latency and packet loss have been investigated. Our analysis show that DMM with semisoft handover at L2 and IP preregistration at L3 can reduce the handover latency up-to 7 ms, and therefore reducing the packet loss per handover upto 1.5 packets for uRLLc services.