Adaptive and Latency-aware Load Balancing for Control Plane Traffic in the 4G/5G Core

For many years, the continuous proliferation of mobile devices and their applications generate a surge of signaling traffic in the control plane of the mobile packet core network. As a consequence, the control plane will potentially become a bottleneck if not properly managed. We focus on the load balancing of a virtualized and distributed Mobility Management Entity (vMME), which is the key control plane element in the 4G and 5G non-standalone cores. Most of existing works use the simple and static load balancing approaches such as round-robin and consistent hashing, which do not work well in a heterogeneous environment. In this paper, we developed three adaptive algorithms in which the balancing decision takes into account the dynamics of the system such as the vMME load, the completion time of a request served by a vMME, and the number of pending requests queued at a vMME. The evaluation of our three proposed load-balancing algorithms in an Open5GCore testbed suggests that the latency-aware scheme helps shorten the completion time of the signaling requests by up to five times the static and dynamic schemes in those cases the link delay between the load balancer and the vMMEs differ signiflcantly.