What are the different Signalling Radio Bearers (SRBs) in 5G and their specific functions?
Tech Junction Answered question July 23, 2024
As we delve deeper into the world of 5G, it’s essential to understand the different Signalling Radio Bearers (SRBs) that play a critical role in the transmission of RRC and NAS messages. Here’s a quick overview of the various SRBs and their specific functions:
- SRB0: – Used for RRC messages via the CCCH logical channel, excluding SRB0 of L2 U2N Remote UE.
- SRB1: – Handles RRC messages (including piggybacked NAS messages) and NAS messages before SRB2 establishment, via DCCH logical channel, excluding SRB1 of L2 U2N Remote UE.
- SRB2: – For NAS messages and RRC messages with logged measurement info, using DCCH logical channel; lower priority than SRB1 and configured post-AS security activation, excluding SRB2 of L2 U2N Remote UE.
- SRB3: – Dedicated to specific RRC messages when UE is in (NG)EN-DC or NR-DC, using DCCH logical channel.
- SRB4: – For RRC messages including application layer measurement reports, using DCCH logical channel; lower priority than SRB1 and configured by the network post-AS security activation.
- SRB5: – For RRC messages with application layer measurement reports, using DCCH logical channel; lower priority than SRB1 and SRB3, configured by the SN serving the SCG when the UE is in NR-DC, post-AS security activation.
Understanding these SRBs is crucial for telecom professionals as they enhance network efficiency and performance, ensuring seamless communication in 5G networks.
Tech Junction Answered question July 23, 2024