Physical Cell ID

PCI Physical Cell ID

Identifier used both in LTE and 5G to uniquely distinguish each cell within a network from its neighbours. It assist UEs during cell search, synchronization, and handover procedures.

• The PCI is assigned to each cell by the network, ensuring that cells geographically close to each other do not share the same PCI, which prevents confusion for UEs during signal acquisition.
• In LTE, there are 504 possible PCIs, grouped into 168 unique groups, with each group containing 3 identities.
• Similar principles apply in 5G NR, with the PCI used for similar purposes during initial access and mobility.