UMTS address can be classified
1. CN address
- IMSI
-TMSI
-P-TMSI
2. UTRAN address
- S-RNTI
- U-RNTI
- C-RNTI
3. UE ID dedicated channels
C-RNTI is allocated by the CRNC when a UE access a new cell.
It is only valid within the cell to which the UE is in.
It is 16 bits and used as the main identity while the UE is in a cell and not using DPCHs.
If the UE leaves the clee, then it needs to use [...]
There are three types of UTRAN addresses:
1. s-RNTI
2. u-RNTI
3. c-RNTI
In the Cell_FACH, the UE location is known to the cell level.
If the UE detects the change in cell identity, it performs a cell update procedure.
The UE is addressed by the C-RNTI(cell radio network temporary identifier) from the RNC that controls the cell which the UE is in.
MAC header includes
1. C/T field: identifies a specific logical channel (when there are multiple logical channels mapped into a single transport channel)
2. UE ID (e.g., C-RNTI): identifies a specific UE when common channels are used (e.g., FACH channel)
*Idle mode: CN-level
UE is identified with TMSI (temporary mobile subscriber identity)
*RRC connected mode: UTRAN-level
UE is identified with C-RNTI and U-RNTI
Cell_FACH and Cell_PCH: every cell change needs to be reported via cell update
URA_PCH: every URA change needs to be reported via cell update
(less signal overhead from UE perspective, but more paging messages need to be injected [...]
RNTI (radio network temporary identifier) is used to address the UE (user equipment) on common transport channels.
If dedicated channels are used, then no need for RNTI.
Two types:
1. C-RNTI (cell)
2. U-RNTI(URA)
C-RNTI identifies a UE within a cell, so it can only be used when the UE’s location is known.
Otherwise, U-RNTI is used.
C-RNTI will be allocated to [...]
