PCI is a comnbination of PSS and SSS that make a range of 0 to 503 unique identities. The objective of cell search procedure within E-UTRAN is to identify one of the 504 unique Physical Cell Identities (PCIs).Hence they need to be unique in order to distinguish a cell from its neighbor cells. Secondly in handover procedure, PCI is one of the key parameters provided to the UE by the network to identify the neighbour cell for HO.therfore the neighboring cells cannot have the same PCI value. To minimize interference, the thumb rule is to ensure that neighboring cells shall not transmit the same PSS. This ensures that sync signal and reference signals do not interfere with each other.
