Integrated Mobility Load Balancing and Traffic Steering mechanism in LTE

Abstract

Mobility Load Balancing (MLB) is a Self-Organising Networks (SON) use case with the scope of detecting and resolving radio overload. In case of overload, the MLB triggers the handover of cell edge users towards less loaded neighbour cells to better align the traffic demand with the capacity available on the air interface. This, however, also increases the load on the transport links of these cells; therefore, MLB should consider the transport status in order not to cause transport congestion while resolving air interface overload. This paper proposes a general MLB framework that, unlike existing mechanisms, has efficient means to properly consider the transport load and congestion in addition to the radio load. The solution is not limited to any particular transport network topology and it also acts as a Traffic Steering (TS) mechanism as it resolves transport overload by redirecting users to neighbour cells with spare transport resources. The performance of the proposed framework was evaluated with simulations. Results indicate that the solution improves the overall system performance by balancing both radio and transport load.