What is SRB1 and SRB2?
What is SRB1 and SRB2?
SRB1 is for RRC messages (which may include a piggybacked NAS message) as well as for NAS messages prior to the establishment of SRB2, all using DCCH logical channel; SRB2 is for RRC messages which include logged measurement information as well as for NAS messages, all using DCCH logical channel.
Why do we need SRB2 in LTE?
LTE SRB2 (DCCH) SRB2 used to transfer RRC messages which use DCCH channel and encapsulates a NAS message. SRB1 is also used to encapsulate NAS message if SRB2 has not been configured. SRB2 has lower priority then SRB1 and it is always configured after security activation.
What is SRB1?
A signaling radio bearer is defined as a radio bearer that is only used for transmission of RRC and NAS messages. SRB1 is used for transport of RRC messages including piggybacked NAS messages as well as NAS messages prior to the establishment of SRB2 where all are associated with a dedicated control logical channel.
What is SRB and DRB in 5G?
In LTE there are two main types of bearers, namely the SRB (Signalling Radio Bearer) and the DRB (Dedicated Radio Bearer). The DRB is used to carry the data associated with an EPS bearer.
What is DRB in 5G?
Access Stratum level, the data radio bearer (DRB) defines the packet treatment on the radio interface (Uu). A DRB serves packets with the same packet forwarding treatment. The QoS flow to DRB mapping by gNB is based on QFI and the associated QoS profiles (i.e. QoS parameters and QoS characteristics).
What is SRB in 5G?
SRB stands for Signaling Radio Bearer.”Signalling Radio Bearers” (SRBs) are defined as Radio Bearers (RBs) that are used only for the transmission of RRC and NAS messages.As defined per 3GPP specification TS38. 331, there are four different types of SRB in 5G New Radio (NR) defined as follows.
How much is Qfi in 5G?
This QFI is carried in an encapsulation header over N3. For each UE, 5GC establishes one or more PDU sessions and 5G-RAN establishes at least one DRB together with PDU session. Additional DRBs are configured for QoS flows of that PDU session consecutively….5G NR QoS Architecture, QoS Attribute and QoS Flow.
Parameter | 5G | 4G |
---|---|---|
Data Session | PDU Session | PDN Connecion |
What is Rqi in 5G?
In 5G, the RQI is contained within the encapsulation header of the downlink user plane in order to notify the device that Reflective QoS is required for that specific SDF (Service Data Flow).
What is SRB1bis?
Signalling Radio Bearers (SRBs) are the Radio Bearers (RBs) that are used by UE for transmitting and receiving RRC messages with the eNodeB. It is established implicitly when establishing SRB1 after the UE receives the RRCConnectionSetup. SRB1bis is the same as SRB1 except that it bypasses the PDCP layer.
What is Qnc in 5G?
QoS Notification Control ( QNC ): Configures NG-RAN to notify SMF if GFBR can’t be met.