Automatic Neighbour Relation is one of the key features of SON (Self Organizing Networks). The ANR function resides in the eNB and manages the neighbor relationship table. Manual configuration and provisioning of neighbors is a very tedious job and it becomes very much difficult to define because of the deployment of already existing technologies. According to 3GPP specifications, the purpose of Automatic neighbor relation (ANR) functionality is basically to relieve the operator from the burden of manually managing neighbor relations. Located within ANR, the neighbor detection function finds new neighbors and adds them to the neighbor relation table (NRT).
The Automatic Neighbor Relation function relies on cells broadcasting their identity on a global level. It allows operations and management (O&M) to manage the NRT. ANR functionality has a significant impact on the network performance in terms of capacity, latency, and scalability. The Neighbor relation table (NRT) held at the base station will contain an entry for each neighboring cell. Each entry will contain all the information the base station needs to know about its neighbor.