Mobility Load Balancing (MLB) is a common technique to deal with the uneven traffic distribution in mobile networks. The aim of MLB is to alleviate congestion problems by sharing traffic demand among neighbor cells through the modification of handover parameters. MLB has been successfully used in legacy radio access technologies. However, in Long Term Evolution (LTE), MLB may lead to severe network performance degradation due to the tight frequency reuse used in this technology.
In this paper, a comprehensive analysis of the limitations of MLB in LTE is done based on the results of a classical MLB algorithm in a live LTE network. Field trial results confirm that MLB reduces network congestion at the expense of degrading cell-edge user performance in the uplink of congested cells and the downlink of adjacent cells receiving traffic.