What is N311?
N311: Maximum number of consecutive “in-sync” indications for the PCell received from lower layers. Reset. Upon reception of “outof-sync” indication from lower layers. Upon receiving RRCReconfiguration with reconfigurationWithSync for that cell group. Upon initiating the connection reestablishment procedure.
What is T311 LTE?
T311 is a supervision timer for the cell selection procedure after a OoS scenario. If before T311 expires the UE finds a suitable cell, it stops T311, starts T301, send RRCConnectionReestablishmentRequest and wait for the eNodeB response. The T301 is a supervision timer for the RRCConnectionReestablishment procedure.
What is LTE T300?
T300. Transmission of RRCConnectionRequest. Reception of RRCConnectionSetup or RRCConnectionReject message, cell re-selection and upon abortion of connection establishment by upper layers.
What is T312 timer?
T312. The timer T312 starts upon triggering a measurement report for measurement identity for which T312 has been configured while T310 timer is running. • It stops upon receiving N311 consecutive in-sync indications from lower layers. • upon triggering the handover procedure.
What is RRC connection reestablishment?
The object of the RRC connection reestablishment procedure is to reestablish the RRC connection, which includes restoring Signaling Radio Bearer 1 (SRB1) and reactivating the security. Scenarios in which a UE needs an RRC connection reestablishment request are defined in the 3GPP RRC protocol.
What is inactivity timer in LTE?
Inactivity Timer A low setting (typically 10 seconds) allows devices to return to idle mode more often, reducing the demand on system resources and increasing the influence of the idle mode mobility configuration.
What is DRB and SRB in LTE?
In LTE there are two main types of bearers, namely the SRB (Signalling Radio Bearer) and the DRB (Data Radio Bearer). The DRB is used to carry the data associated with an EPS bearer.
What is difference between Rrcconnectionreconfiguration and RRC re establishment?
RRC CONNECTION RECONFIGURATION message is the command to modify an RRC connection. While the purpose of RRC CONNECTION RE-ESTABLISHMENT procedure is to re-establish the RRC connection, which involves the resumption of SRB1 operation and the re-activation of security (without changing algorithms).
What is RRC inactive state?
Overview of RRC Inactive state: In 5G, they have introduced new RRC Stats called “RRC Inactive” to minimize latency as well as to reduce signalling load. Transitions from RRC Inactive to Connected is very quick as UE Context is stored at gNB and UE.
What is UE inactivity timer?
When the eNodeB detects a UE which does not have any traffic to send and receive during a defined period of time, usually referred to an inactivity timer (20s, 10s etc…) which is defined in eNodeB and also is configurable, then the eNB can initiate procedures to place the UE in idle mode.
What is IMS in VoLTE?
The Ribbon VoLTE and IP Multimedia Subsystem (IMS) solution combines robust IMS service functionality with the ability to securely and intelligently route high volumes of Session Initiation Protocol (SIP) and Diameter traffic together with media processing and transcoding at both the core and the edge of the network.
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.
How many SRB is LTE?
As mentioned in the LTE SRB table, there are three types of SRB in the LTE technology. SRB0 used to transfer RRC messages which use CCCH channel. SRB1 used to transfer RRC messages which use DCCH channel. SRB2 used to transfer RRC messages which use DCCH channel and encapsulates a NAS message.
What is re establishment in LTE?
The purpose of RRC CONNECTION RE-ESTABLISHMENT procedure is to re-establish the RRC connection, which involves the resumption of SRB1 operation and the re-activation of security (without changing algorithms). The UE shall only initiate this procedure when AS security has been activated.
What is the difference between RRC IDLE and RRC inactive?
When UE is power up it is in Disconnected mode/Idle mode, It can move RRC connected with initial attach or with connection establishment. If there is no activity from UE for a short time, It can suspend its session by moving to RRC Inactive and can resume its session moving to RRC connected mode.
What is the difference between n310 and n311 and t310?
N310 and N311 are number of out-of-sync and in-sync indications respectively and T310 and T311 are timers related to RLF and RRC Conncetion Re-establishment procedures. Number of consecutive out-of-sync indications from lower layers. If reached, it triggers T310 timer.
When to use constants n310 and n311 in 5G NR system?
When the 5G NR UE applies zero value for the timer, the timer shall be started and immediately expire unless explicitly stated otherwise. Following table mentions usage of constants N310 and N311 in 5G NR system. • N310: Maximum number of consecutive “out-of-sync” indications for the PCell received from lower layers.
What is t310 and t311 radio link failure timer?
T310: radio link failure declaration timer (*N310 out of sync indications). N310: number of consecutive “out-of-sync” indications received from lower layers that triggers timer T310. T311: radio link failure recovery timer (connection re-establishment procedure).
What is a N310 error?
N310 indicates an interval of 200 PDCCH decoding failures. Simply put, if the UE fails to decode PDCCH for 200ms, it will be considered one N310. However, from here onwards, it is a sliding window with 10ms granularity.