with the target base station, the target base station can still send its own cell configuration to the initiation base station. The received information can then be compared with the existing ones and updated in cases of identified modifications. Automatic Neighbor Relation Updates This aspect is mainly 3GPP driven and is based on UE's measurement reporting. This means the UE detects the neighbor's signal strength and then reports to the serving cell with the PCID of the new cell. The serving cell is then based on these measurements, and it will add the newly discovered cell to its neighbor list. CHAPTER 2 SELF-ORGANIZING NETWORKS IN LTE DEPLOYMENT However, the relationship between neighbor cells needs to be known by the respective base stations and should be planned accordingly because wrong configurations can result in a high rate of handover failures and call drops. Automatic neighbor relation updates can be broadly classified as a four-step procedure: Neighbor cell detection X2 configuration discovery of the neighboring site The X2 connection setup Neighbor relation optimization Neighbor Cell Detection An LTE cell can be identified in two ways. First, it is identified with the help of PCID, which is used for most of the RRC signaling, as it requires fewer bits for transmission. LTE cells can be identified and classified as neighbors based on the PCID; however, because there are only 504 possible PCIDs, there is a risk of a duplicate PCID being used by two different cells that are close to each other. The radio network planning and optimization engineers should ensure that for a particular coverage area, there are no two cells with the same PCIDs to avoid any conflicts. Second, the LTE cell can be identified with the help of E-UTRAN cell global ID (E-CGI) broadcasted as part of the SystemInformationBlock1, E-CGI is unique in the whole network and allows an unambiguous identification of a cell. Figure 2-6 shows the relation between the PCID and the E-CGI. PCID of the cell is transmitted as a part of reference s