LTE UE uplink network entry/random access procedure

This page describes LTE UE network entry procedure which covers cell search procedure, system information decoding and random access procedure as required for LTE UE to complete network entry with eNB.

LTE UE uplink network entry random access procedure

The figure depicts all the process as required for LTE UE to camp on to LTE compliant eNB or LTE cell. Step 1: LTE UE uses PSS and SSS to determine physical layer cell identity (PCI) (1 out of 504).
For more visit our page on LTE UE cell search procedure.

Step 2: After cell search procedure is completed, LTE UE decodes following using PBCH channel.
Master Information Block which is transmitted on BCH at the periodicity of 40ms, which is carrying system bandwidth, PHICH configuration, SFN number of transmit antennas.

System Information Block Type 1 which is transmitted on DL-SCH at the periodicity of 80ms, which is carrying PLMN IDs, tracking area code, cell identity, access restrictions, scheduling information and more. SI-RNTI is used on PDCCH to address System Information Block Type 1 and SI Messages.

Step 3 (a) : Random access procedure is intiated by UE by sending random access preamble on PRACH. eNB responds with random access response on PDSCH.

Step 3 (b) : The data transmission is scheduled on PUSCH. The contention resolution is taken care by MAC and the same is intimated to UE by eNB on DL-SCH.

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