UETR

• UETR = User Equipment Traffic Recording• UETR is a performance recording tool of inter-node events and

measurements for a specific UE (identified by its IMSI) that the RNC records.

• Only dedicated events with UE identifier is filtered and recorded in UETR.

• Events are recorded in 15min ROP. (UETR file size is 15min)• A maximum of 16 simultaneous UETRs are allowed per RNC• If measurements across RNC border to another RNC are

needed, the neighboring RNC needs to be activated for measurement.

• File Storage Retention period: 2 days

Interfaces in UTRANThe UTRAN network elements are connected by 4 Interfaces internally or

externally to each other:

Signalling protocol messages• RRC ( UE RNC )

The RRC (Radio Resource Control) handles the Layer 3 control signalling between UE and RNC and performs functions for – connection establishment and release, – broadcast of system information, – Radio Bearer establishment/reconfiguration and releases, – RRC Connection mobility procedures, – paging notification and release, – outer loop power control.

• NBAP ( RBS RNC )NBAP (Node B Application Part) is the signalling protocol responsible for the control of NodeB by RNC. NBAP is carried over Iub.

• RNSAP ( RNC RNC ) RNSAP (Radio Network Subsystem Application Part) is a signalling protocol responsible for communications between RNCs. It is carried on the Iur interface and provides functionality for

– SHO – network configuration relocation.

• RANAP ( CN RNC ) RANAP (Radio Access Network Application Part) is a signalling protocol between

Core Network (CN) and the RNC. RANAP is carried over Iu-interface. RANAP is used for the following tasks:

– Relocation– Radio Access Bearer Management– Paging– Transport of signalling between a UE and the Core Network (non-access stratum signalling)

• NAS ( UE CN ) NAS (Non Access Stratum) is a functional layer running between the UE (User Equipment) and the CN (Core Network) and supports traffic and signalling messages between the CN and UE.

Activate UETR & CTR 1

2

3

1

5

4

32

6

1

5

43

2

UETR FILE Parser

• In CYGWIN decoder directory, type in:cat Uetr_p_1301133253349.txt | /home/arban/decoder/decoder.pl

--w10b | /home/arban/decoder/flow.pl > UETR_Output.txt

Output fileWill be delete

Uetr file

• UETR_Output.txt

Will be delete

Some Iu-Release ExampleExamples of Iu-Releases:• Normal Release• UE-inactivity• OM-Intervention • Radio-connection-with-UE-Lost

Iu-Release cause: Normal-release

• RANAP message contains the cause of the Release. In case of Normal Release (cause: “normal release”)

UE-inactivity

• This type of Iu-Release is caused by UE inactivity and is considered as not real dropped connection. Inactivity Timer expires - “downswitchTimer” for R99 or “hsdschInactivityTimer” for HS.

• When the throughput on both UL and DL is below the “downswitchThreshold”, the timer “downswitchTimer” (DCH/DCH) or the “hsdschInactivityTimer” (DCH/HS or EUL/HS) starts.

OM-Intervention

• This type of Iu-Release is caused by any O&M action in the site or RNC (reset/parameter change which requiers site reset) and is real dropped connection.

Radio-connection-with-UE-Lost• This type of Iu-Release is caused bad RF condition or synchronization

failure. This is a real dropped connection. To find out more details of the cause of this Iu-Release the UEH exception logs* should be checked (*Need RNC Support).

Note possible RL failure indications!

Check also RL quality indicators (CPICH – EcNo / CPICH – RSCP) in (RRC) MR messages (measID=1)