Mobile cellular networks are typically engineered by operators to provide diverse sets of voice and data services to groups of users sharing network resources. In a standard configuration, each of the networked radio coverage cells (also known as “sectors”) are arranged to provide static contiguous wireless coverage within a regional service area. Users of a mobile cellular network connect to the network via user equipment terminals (UEs), which attach wirelessly to one or more of the cells.
The network and the UEs support handover services, which provide continuous and uninterrupted user-perceived communication as users move between coverage cells. For example, the network may handover a UE from a first cell to a second cell when the UE moves from the first cell into the second cell.
Because of a random distribution of users and a varying demand for voice and data services, traffic loads vary from cell to cell. Adjoining or overlapping cells may have dramatically different loads over time.
When a cell experiences more demand for resources than it can satisfy, the cell is “congested.” When the cell is congested, overloaded shared resources within the cell may be allocated on a fair basis among the UEs attached to the cell. However, each UE is allocated fewer resources when the cell is congested than when the cell is not congested. Those reduced allocations during congestion may be insufficient for certain high data throughput services, such as video services or timely large file delivery services, e.g., downloading email attachments. Congestion is therefore a condition to be avoided whenever possible.
Accordingly, mobile networks, when possible, “load balance” cells by handing over UEs between serving cells. Load balancing prevents scenarios, for example, where one cell is operating in congestion, and another neighboring or overlapping cell is idle. Load balancing tends to maximize the usage of the aggregate capacity of the cellular network, improve the economic use of deployed infrastructure, and improve quality of experience for users of the mobile network.
For example, operators may trigger load balancing between cells whenever a numerical threshold difference exists in the aggregate traffic loads between adjoining or overlapping coverage cells that have one or more operating UEs in a common coverage area. For example, by forcing or biasing handover of UEs from a higher traffic load cell to a lower traffic load cell, the aggregate traffic load levels between the two cells are driven towards equilibrium, and general congestion may be lessened.
Existing methods, however, currently lack novel methods of triggering and executing load balancing to more efficiently and equably reduce overall network congestion that may be aligned with Self-Organizing-Network (SON) principles.