4g LTE: LTE NAS layer introduction and procedures
NAS layer : Non-Access Stratum: This is used to communicate control plane information between UE and MME. NAS layer protocols functions are to…
4g LTE: RRC Connection Re-Configuration Procedure
The purpose of this procedure is to: – Establish/modify/release RBs, – To perform Handover – To configure/modify…
4g LTE: RRC Connection Re-Establishment
This procedure will be initiated by UE on below scenarios: 1. Upon re-entry into service area after radio link failure 2. Handover failure 3.…
4g LTE: RRC Connection Release Procedure
RRC Connection Release procedure is used to release an RRC Connection. Here eNB initiates the RRC connection release procedure to the UE. Then…
4g LTE: RRC Connection Establishment Procedure
Once the Random access procedure is completed, the next step is to RRC connection establishment procedure. This procedure will change the…
4g LTE: LTE UE PLMN selection
Once the UE reads PSS and SSS, the next step is to select a PLMN in the initial acquisition procedure. UE will first scan all the available…
4g LTE: RRC Timers in LTE
T300: Start: Transmission of RRCConnectionRequest Stop: Reception of RRCConnectionSetup or RRCConnectionReject message, cell re-selection and…
4g LTE: LTE SBI1 and SIB2
In the previous 2 chapters we learn about MIB and different types of SIBs. In this chapter we shall learn more about SBI1 and SIB2. As these 2…
4g LTE: Cell Search Procedure and Cell Selection Procedure in LTE
Once the PLMN is selected, the next step is to select a suitable cell inside that PLMN to camp on. Then after camping on, UE will frequently…
4g LTE: LTE Signalling Radio Bearers Mapping
Signalling Radio Bearers (SRB) are used to transmit RRC and NAS messages. We know that there are total of 11 radio bearers. The first 3 types…