Autonomous Neighbour Relation Detection and Handover Optimization in LTE

Radio access technologies (RATs) which are in use today demand for a high effort in deployment and maintenance by their operators. For this reason, operators demand for a significant reduction of this effort for the development of future RATs. Configuration tasks that have to be executed during deployment as well as optimization tasks during operation shall therefore be performed as far as possible by the network itself, i.e. by self organization. The generation of neighbour relation tables (NRTs) for every cell of a network is one of the above configuration tasks. A cell knows through its NRT suitable neighbours for handovers (HOs) of its served mobile terminals. Currently, these NRTs have to be set up manually, only supported by network planning tools and costly drive tests. In the upcoming 3GPP Long Term Evolution (LTE) technology [1], each E-UTRAN NodeB (eNB), which is the used term for a base station, shall generate NRTs for its served cells by triggering selected connected User Equipments (UEs), which is the used term for mobile terminals, for neighbour cell measurements and interprets the reported results. This function is called Automatic Neighbour Relation (ANR) [1]. Besides the usage of NRTs, handovers are controlled by a number of parameters determining key performance indicators such as total HO rate, HO success rate, or throughput at cell edge. For