In a typical cellular network, also referred to as a wireless communication system, User equipment, UEs, communicate via a Radio Access Network, RAN, to one or more core networks, CNs.
A UE is a mobile terminal by which a subscriber may access services offered by an operator's core network and services outside operator's network to which the operator's RAN and CN provide access. The UE may be for example communication devices such as mobile telephones, cellular telephones, smart phones, tablet computers or laptops with wireless capability. The UE may be portable, pocket-storable, hand-held, computer-comprised, or vehicle-mounted mobile devices, enabled to communicate voice and/or data, via the radio access network, with another entity, such as another mobile station or a server. The UE may also be a Machine-to-Machine, M2M, communication device that serves as a data communication modem or is built into equipment communicating data with a server without human interaction. UEs are enabled to communicate wirelessly in the cellular network. The communication may be performed e.g. between two UEs, between a UE and a regular telephone and/or between the UE and a server via the RAN and possibly one or more CNs, comprised within the cellular network.
The RAN covers a geographical area which is divided into cell areas, with each cell area being served by a base station, e.g. a Radio Base Station, RBS, which in some RANs is also called eNodeB, eNB, NodeB, B node or network node. A cell is a geographical area where radio coverage is provided, via antennas, by the radio base station at a base station site. Each cell is identified by an identity within the local radio area, which is broadcast in the cell. The base stations communicate over the air interface operating on radio frequencies with the user equipment within range of the base stations. It should be noted that a base station may serve more than one cell, which may then also be referred to as a base station site.
A base station may also comprise so called adaptive or reconfigurable antennas. Adaptive antennas enable the base station to in flexible way configure the antennas in order to adapt to real UE spatial traffic distribution. For capturing the real UE spatial traffic distribution, the base station can measure signal strength, e.g. the Reference Signal Received Power, RSRP, and direction, e.g. Angle of Arrival, AoA, of user equipments transmissions. Also, the antenna beam can be adjusted to provide high antenna gain in order to better capture real UE spatial traffic distribution.
By adjusting parameters of the adaptive antennas to the real UE spatial traffic distribution, improved radio coverage can be achieved. Also, interference can be reduced by adjusting adaptive antenna parameters. Some examples of antenna parameters for which the adaptive antennas may be adjusted are antenna beam width and antenna pointing direction. For example, an antenna beam width can be formed so as to reduce the interference in the direction of a neighboring cell, wherein the direction of the interfered UEs can be measured by AoA on the uplink.
However, co-ordinating or optimizing antenna configurations in large wireless communications networks having many interfering cell or antenna relations and high density UE spatial traffic distributions is a multi-dimensional task that is highly complex. For example, it is not uncommon with 20 or more neighboring cells or antennas of multiple network nodes that potentially need to be coordinated from interference point of view.