1) The document discusses various states and procedures in LTE including UE states, PLMN selection, idle and connected mode procedures, cell selection and reselection processes, system information block messages, and mobility events.
2) Key UE states include EMM registered, EMM de-registered, and ECM idle/connected states. Cell selection is based on measurements of the S-criterion while cell reselection considers factors like signal level compensation and cell ranking criteria.
3) System information blocks provide parameters for functions like neighboring cell measurement, priority settings for inter-frequency/RAT reselection, and thresholds for mobility events during connected mode.
6. SIB MESSAGES
MIB : Master Information Block: Most essential parameters
SIB 1: Cell access related parameters and scheduling
SIB 2: Common and shared channel configuration
SIB 3: Parameters required for intra-frequency cell reselections
SIB 4: Information on intra-frequency neighboring cells
SIB 5: Information inter-frequency neighboring cells
SIB 6: Information for reselection to UMTS (UTRAN) cells if no suitable LTE cell
is available
SIB 7: Information for reselection to GSM (GERAN) cells if no suitable LTE or
UMTS cell is available
SIB 8: Information for reselection to CDMA2000 systems (mostly for North
America)
SIB 9: Home eNodeB name – for future LTE femto cell applications
SIB 10 + 11: ETWS (Earthquake and Tsunami Warning System) information
8. Cell selection consists of the UE searching for the strongest cell on all supported carrier
frequencies, of each supported RAT until it finds a suitable cell.
The cell selection criterion is known as the S-criterion and is fulfilled when the cell selection
receive level value Srxlev > 0
Srxlev = Qrxlevmeas − (Qrxlevmin − Qrxlevminoffset)
Srxlev is the Signal level compensation
Qrxlevmeas is the measured cell receive level value, also known as the RSRP
Qrxlevmin is the minimum required receive level in the cell.
Qrxlevminoffset is an offset which may be configured to prevent ping-pong between PLMNs.
SIB 1 provides parameters for Cell Selection.
Default value for qrxlevmin = -120dbm.
CELL SELECTION
13. UMTS TO LTE RESELECTION
UE reselects to LTE ONLY WHEN UE IS IN IDLE MODE.
UE shall perform reselection when measured RSRP goes higher than
threshXhigh.
SIB 19 provides the parameters for reselection.
UMTS NodeB Serving
eNodeB Neighbour
UE should be in
IDLE MODE
15. LTE - ATTACH
The following are required for initial attach to the LTE network:
The Master Information Block (MIB), which includes a limited number of the most frequently
transmitted parameters which are essential for a UE’s initial access to the network.
System Information Block Type 1 (SIB1), which contains parameters needed to determine if a cell
is suitable for cell selection, as well as information about the time domain scheduling of the other
SIBs.
System Information Block Type 2 (SIB2), which includes common and shared channel
information.
UE eNB
Master Information Block
SIB 1
SIB 2
MIB
• DL bandwidth
SIB 1:
• PLMN ID
• TAC
• PCI
• Scheduling info for SIB2
SIB 2:
• Common Channel Info
• RACH info
• Random Access preamble
info
•T300 value
16. LTE - ATTACH
RRC Connection Request
UE starts T300 timer after sending RCC
connection request.
Value of T300 is available in SIB2.
T300 value determines how long to wait to
get a response from eNB.
Upon receiving RRC connection Setup, UE
stops T300 timer.
UE send RRC Connection setup Complete
to make its transition to Connected mode.
RRC Connection Setup Complete
17. Event A1: Serving becomes better than absolute threshold.
Event A2: Serving becomes worse than absolute threshold.
Event A3: Neighbour becomes amount of offset better than serving.
Event A4: Neighbour becomes better than absolute threshold.
Event A5: Serving becomes worse than absolute threshold1 AND Neighbour becomes better
than another absolute threshold2.
Event B1: Neighbour becomes better than absolute threshold;
Event B2: Serving becomes worse than absolute threshold1 AND Neighbour becomes better
than another absolute threshold2.
LTE EVENTS
Connected mode mobility is handled by LTE events.