C 2 6270 Call-Connection Analyses 002 KH

TA-TC 6270 /Version 01/Chap. 02 Call-connection analyses

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2.Call/connection analyses

2.1 Procedure related KPIs in UTRAN 2.2 NAS procedures 2.3 PS traffic in UTRAN 2.4 HSDPA Link Analyses


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2.1 Procedure related KPI in UTRAN for CS traffic2.1.1 Service concept2.1.2 Call Establishment PagingRRC connection setupSignalling Connection Establishment Radio Link setupRAB assignmentCall Setup Success Rate2.1.3 CallReleaseRAB ReleaseSignalling Connection ReleaseRRC Release Radio Link ReleaseCall/RAB drops2.2 NAS procedures2.2.1 MM proceduresLocation Updates Authentication Ciphering initialization2.2.2 CC proceduresCall setupCall Release

2.2.3 GMM Location Updates Authentication Ciphering initialization2.2.4 SMPDP context activation/modification/ deactivation2.3 Procedure related KPI in UTRAN for PS trafficRadio Bearer ControlPS RAB assignment RRC StatesTransport Channel Reconfiguration


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Service conceptService concept:One RRC connection is initiated by the UE and established with the help of the Serving (S-) RNC. In the first RRC initialDirectTransfer message the UE will indicate the corresponding CN entitiy(CS or PS). Now a signalling (SCCP) connection has to be established by the SRNC towards thecorresponding core network. Now the UE can exchange NAS signalling, can for example request services. The service is handled in UTRAN as RAB. Several services may be active at a time. UE may have an active video call while making a phone call while browsing the internet. So the UE may have a maximum of one RRC connection, one SRNC, two SCCP connections and many active RABs (depending on the phones capability).The PS core network in release 99 gives support for background and Interactive services, is enhanced to support streaming class in Rel 4 (guaranteed bandwidth) and Rel 5 gives support for conversational packet switched services.The signalling connection between CS CN and UE is referred to as RR connection and theconnection between UE and PS CN is referred to as GM connection.Call versus ConnectionWithin this document KPIs will be defined analyzing calls and analyzing connections. In this approach calls will be analyzed if a RAB establishment/release is involved. Thus, a call is not related only to a voice connection but also to PS connections. A connection is established between the UE and the Core Network and allows the transfer of NAS signalling (examples are location updates, Routing area updates, the transfer of SMS, attach, detach or a call-RAB-establishment).


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Service concept

1 RRC Connection SRNC

1 SCCP Connection

1 SCCP Connection

0, 1 or more RABs

0, 1 or more RABs

MSC/MSC server:Support of

ConversationalStreaming services

SGSN:Support of

Background (Rel 99, Interactive (Rel 99) Streaming (Rel 4) Conversational (Rel 5)

services

0, 1 or more RABs

0, 1 or more RABs

RR connection

GM connection


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Service concept

RRC Connection

RRCconnected

CELL_DCH

CELL_PCH

CELL_FACH

URA_PCH

RRC substates

No RB and no Signalling Radio Bearer (except SRB 0 which is possible in RRC idle as well) is configured in the UE

SRB configured plus optional Radio Bearer RB


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Call establishment

Mobile Terminated Call

Mobile Originated Call

Paging RRCconnectionSignallingconnection

RadioLink

RABassignment

Call setup and release: The procedure of setting up a call depends on whether the call is mobile-originated or mobile-terminated. In case of a mobile-terminated call (MTC), the process starts with paging. Paging is the procedure by which a mobile network attempts to locate the UE within its location area before any other network-initiated procedure can take place. If the UE originates the call, paging is not needed and the UE directly requests RRC connection setup. After having established an RRC connection, the UE starts setting up a signalling connection to the CN. Radio Link may be established.

Finally, the radio access bearer setup procedure builds a radio access bearer service between the UE and the core network (CN), and the call is established.A call setup in UTRAN can be described by the concatenation of the phases1. RRC connection establishment2. NAS signaling connection establishment3. RAB establishment


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Paging

Paging is initiated by the CN to find a specific UE. In idle mode, paging is always initiated by the CN. In CSpaging, the CN and further the RNC broadcast paging messages through base stations of the location area in which the UE is situated. In PS paging, the CN and further the RNC broadcast paging messages through base stations of the routing area in which the UE is situated. To save on power consumption, the UE can use discontinuous reception (DRX). This means that the network pages the UE according to a preset sequence of frames during specific intervals. This preset frame sequence interval is called a DRX cycle. DRX cycles can vary in length, and in case the UE is connected to two different CN domains with different DRX cycle lengths.The RNC sends paging requests to all WCDMA BTSs which belong to the paging area where the UE is currently registered. The cells in a single Node B can belong to different paging areas. Each paging message on the Iu interface has to be packed into a suitable RRC message. The RNC checks whether the paged UE has an ongoing Radio Resource Control (RRC) connection.

-If there is no connection, the RNC starts the idle mode paging procedure and the UE starts the RRC connection setup procedure.

-If there is a connection, the RNC checks the RRC state of the UE. Depending on the current RRC state, the RNC initiates a UE dedicated paging procedure or a connected mode paging procedure.


RadioLink

RABassignment


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Paging: UE in Idle Mode

RRC: Pag Type 1

Terminating conversational call Terminating streaming call Terminating interactive callTerminating background call Terminating high priority signaling Terminating low priority signaling Terminating - cause unknown

UDT RANAP: Paging

Paging ResponseRRC connection establishment

The RNC checks whether the paged UE is RRC connected. If not, the RNC starts the idle mode paging procedure

The CN node verifies the success of the paging, it may retransmit the paging if there

is no paging response

UE picks up cause and uses it to request the RRC connection

RRC_Idle

RRC_connectedCELL_DCH CELL_FACH


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Paging: UE in Connected Mode

RRC: Pag Type 2

UDT RANAP: Paging

CELL_PCH

URA_PCH

RRC connection

Serving

Signalling connection to other CN

CELL_DCH

CELL_FACH

If the UE is in UTRA RRC connected mode (has existing NRT RAB), also the RRC state of the UE is checked. Depending on the current RRC state, the RNC initiates a UE-dedicated paging procedure or a connected mode

paging procedure.

dedicated paging

connected mode pagingRRC: Pag Type 1 The paging procedure can be triggered due to

an idle mode paging received from the CS CN or due to downlink data (or signalling) received

from the PS CN.

Paging Response

Paging ResponseRRC: Cell Update


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Paging types

PAGING

CN originated

PAGING

RNC originated PAGING

Originated by PS CN

RRC_Idle

CELL_PCH

CELL_DCH

CELL_FACH*

Pag Type 1

Pag Type 2

Pag Type 2

RRC_Idle

CELL_DCH

CELL_FACH

URA_PCH

CELL_PCH

URA_PCH

CELL_FACH*

Pag Type 1

Pag Type 2

Pag Type 2

Pag Type 1

Pag Type 1

Pag Type 1

Pag Type 1

RRC connection request

Possible if SMS is on FACH

RRC connection request

initial Direct Transfer


Cell Update



Cell Update

Cell Update

Cell Update

Paging initiation UE state Type Success-message


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If there is no response received from the UE, the CNrepeats the paging in a predefined interval. Thepaging is sent on the Paging Channel. One or several UEs, in idle or connected mode, can be paged in one message.

If there is no response

received from the UE,

the RNC repeats the

paging procedure in a

predefined interval.

Paging loadPaging messages per cell

Paging type 1

Paging type 2

UTRAN originated(not triggered by CN)

CN originated(CS or PS)

UE in cell_FACHCS paging

UE in cell_DCHCS or PS pagingCN originated

(CS or PS)

UE in URA_PCHCS paging

UE in cell_PCHCS paging

UE in RRC idleCS or PS paging

UE in URA_PCH

UE in cell_PCH

The paging load per cell depends on the originator of thepaging and the RRC state

Paging is done in all cells of-1 Location Area (CS)-1 Routing Area (PS)

Paging is done in one cell

Paging is done in one URA

Paging is done in one URA

Paging is done in one cell

There is a dedicated signalling link allocated for the UE in the Uuinterface. The paging is not senton paging channelDCCH

PCCH


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Paging related KPIs

Paging related KPI input into the perceived user quality. The paging load is mainly afected by the LA-RA size and the usageof packet switched services (UE on CELL_PCH, URA_PCH):

Number of pagings per cell seen on Iu/Uu, sums up all kind of pagings (type 1 and 2)Number of RNCoriginated paging all pagings type 1 for PS services (State transmissions may be optimized)

A further analyses could be made according to the establishment cause:

Number of pagings per cell (paging cause) distinguishes according to CS/PS, service type.Number of RNCoriginated paging (paging cause)

Successfull events are seen on Iub:

Number of successful CN originated paging Type 1 in IDLE state (RRC Establishment)Number of successful CN originated paging Type 1 in URA/PCH state (Cell Update)

Success rates can be defined by the ratio of CN originated Paging Type 1 where a response from theUE has been received in CELL_PCH/Idle state, related to the total number of CN originated Paging Type 1 messages. A further distinction may be made for the state, the UE is in.

Success rate of CN originated paging Type 1 in IDLE state (all RRC Establishments received in relation to all pagingswhich are sent, makes no sense on cell level, should be seen on RA/LA area level, better observed on Iu interface)Number of successful CN originated paging Type 1 in PCH state (all Cell Update with cause answer to paging in relation to the number of pagings sent per cell )


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Paging-success

CN originated Paging

Paging type 1

Paging type 2

RRC connectionsetup

Cell update

RRC: initial DirectTransfer

Paging success

Cause:-Answer to paging

RANAP: initial UE message

on Iub on Iu

Cause: -Terminating Conversational Call,-Terminating Streaming Call,-Terminating Interactive Call,-Terminating Background Call,-Terminating High Priority Signalling,-Terminating Low Priority Signalling,-Terminating cause unknown,

on Iuon Iub

RANAP: Paging

UE in RRC idle

UE in cell/URA_PCH

UE in cell_DCH/FACH


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Paging failures, RRC connected

UDT RANAP: Paging

Serving

UDT RANAP: Paging

CN originated pagings will be repeated by the CN if not

succesfull

CELL_PCH

URA_PCH

RRC: Pag Type 1

In case of the UE being in URA_ or Cell_PCHstate the RNC may repeat the paging.

If no response: Time out!

In case of the UE being in URA_ or Cell_PCH state theUE may respond with an RRC status message ndicatingprotocol error

RRC: Pag Type 1

RRC STATUS

-ASN.1 violation or encoding error

-Message type non-existent or not implemented

-Message not compatible with receiver state

-Information element value not comprehended

-Conditional information element error

-Message extension not comprehended

Causes


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RRC connection setup

The radio resource control (RRC) connection is always initiated by the UE. The UE sends a message to the RNC requestingRRC connection setup. The RNC sets up a radio link and sends the UE the physical channel information. After the UEhas synchronised itself to the WCDMA BTS, it transmits an acknowledgement to the RNC. Once the UE has set up the RRC connection, it can send higher-layer messages, for instance, a call setup message.

The RRC Connection Request contains the initial UE ID (IMSI,TMSI and LAI, P-TMSI and RAI or IMEI) and is the first message transmitted by the UE when setting up an RRC Connection to the network. (RLC-SAP: TM, Logical channel: CCCH, Direction: UE o UTRAN), UE can indicate HSDPA, EUDCH support.

RRC CONNECTION SETUP (New U-RNTI, RRC State Indicator [CELL_DCH, CELL_FACH]) This message is used by the network to accept the establishment of an RRC connection for a UE, including assignment of signalling link information, transport channel information and optionally physical channel information.(RLC-SAP: UM, Logical channel: CCCH, Direction: UTRAN o UE), contains new U-RNTI, Signalling Radio Bearers.

CONNECTION SETUP COMPLETE this message confirms the establishment of the RRC Connection by the UE.(RLC-SAP: AM, Logical channel: DCCH, Direction: UE o UTRAN) contains UE Radio Access Capability .

RRC CONNECTION REJECT The network transmits this message when the requested RRC connection cannot be accepted (RLC-SAP: UM, Logical channel: CCCH, Direction: UTRAN o UE), Rejection cause (congestion, unspecified), Wait time (useT314, useT315). May contain Redirection info Information Element. This IE is used to redirect the UE to another frequency or other system. With the Release 6 version a list of cells may be provided to the UE, where cell selection shall be started (the success can not been seen in UTRAN and the RRC connection is not successfully established.


RadioLink

RABassignment


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UE

RRC CONNECTION REQUEST

RRC CONNECTION SETUP

RRC CONNECTION SETUP COMPLETE

Establishment cause:-Originating Conversational Call,-Originating Streaming Call,-Originating Interactive Call,-Originating Background Call,-Originating Subscribed traffic Call,-Terminating Conversational Call,-Terminating Streaming Call,-Terminating Interactive Call,-Terminating Background Call,-Emergency Call,-Inter-RAT cell re-selection,-Inter-RAT cell change order,-Registration,-Detach,-Originating High Priority Signalling,-Originating Low Priority Signalling,-Call re-establishment,-Terminating High Priority Signalling,-Terminating Low Priority Signalling,-Terminating cause unknown,

Since Rel. 5 the UE will report the Release (Rel 5, Rel 6, Rel 7And since Rel 6 the UE will indicate the support of HSPA, HSDPA

T300

T300 expires:Retransmission

of RRC

CONNECTION REQUEST

RRC CONNECTION REJECT


Stop T300

CongestionUnspecified

Redirection info

Terminating is foundafter a paging, the UE

picks up the cause received there (if

given)


RRC connection setup retry timer


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Based on the establishment cause the RNC may decide to set up the RRC connection either in dedicated transport channel (DCH) state (could be done for any kind of establishment cause) or in common transport channel (RACH/FACH) state (in

case of NAS signalling for example)

Decision: DCHAdmission Control

Allocation: RNTI, RR, Code

Decision: CCHAllocation: RNTI

CCCH

CCCH

DCCH

CCCH

CCCH

CCCHRRC CONNECTION SETUP COMPLETE

Radio Link Setup


Cell_FACH

Cell_DCH


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RRC connection setup on DCH



Standard is to make the establishment on the Cell DCH

CCCH

CCCH

DCCH


Cell_DCH

Admission control (UL, DL)?Code Resources?

RNTI?Transport resources?

RNC resources?BTS resources?

All issues related with theRadio Link, which is required

in this case.L1 synchronization

ALCAP:ERQ

NBAP: RL Setup Request

Start TX/RX

NBAP: RL Setup Response

ALCAP:ECF

NBAP: Synchronisation Indication


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Directed RRC connection setup

NODE B

Directed RRC connection setup provides an efficient way to balance the load between two (or more) carrier frequencies (cells having equal coverage areas) within one BS or to separate Rel 99 UEs from HSPA capable UE. The RNC balances the load by establishing an RRC connection on the carrier frequency (cell) which has less load or HSDPA active. The admission control of the RNC makes a decision on whether to perform the directed RRC connection setup procedure. Directed RRC connection setup is controlled with RNP parameters.

Cell 1: f1

Cell2: f2


RRC CONNECTION REJECT (Redirect info)PRACH, f1

S-CCPCH, f1RRC CONNECTION SETUP COMPLETE

DPDCH, f2No request in cell 2 is seen, just success.


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RRC connection analyses

Number of RRC Connection Establishments attempts (visible on Uu, Iu interface): The total number of RRC connection Establishment attempts is an important indicator for activity and it is the basis for a

more detailed analyses in calculating success-rates:Calculated per cell:RRC connection Establishment attempts : 6over all RRC CONNECTION REQUEST messages received per cell

A further distinction may be done for different QoS classes

RRC connection Establishment attempts (interactive) : 6over all RRC CONNECTION REQUEST(cause: interactive, terminating interactive)

RRC connection Establishment attempts (streaming) : 6over all RRC CONNECTION REQUEST(cause: streaming, terminating streaming)

RRC connection Establishment attempts (conversational) : 6over all RRC CONNECTION REQUEST(cause: conversational, terminating conversational)

RRC connection Establishment attempts (streaming) : 6over all RRC CONNECTION REQUEST(cause: streaming, terminating streaming)

Terminating cause unknown will only be found in networks, where the QoS class is not indicated in the paging. Then mobile terminated traffic cannot be classified to any specific class.

An RRC connection setup success-rate may be based on all RRC connection Establishment request messages received, which give a 100%. The proportion of successful to all events gives the success rate, the relation of unsuccessful to all events the failure rate.

RRC Connection Establishments successrate = x100%RRC Connection Establishments successRRC Connection Establishments attempts

RRC Connection Establishments failure rate = x100%RRC Connection Establishments failuresRRC Connection Establishments attempts


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RRC analyses

RRC Connection Establishments

Number of RRC connection establishments Number of RRC connection establishments Conversational callsNumber of RRC connection establishments Streaming callsNumber of RRC connection establishments Interactive callsNumber of RRC connection establishments Background callsNumber of RRC connection establishments Low priority SignalingNumber of RRC connection establishments High priority Signaling

Congestion

Unspecified

Redirections

No reply

Other causes

RRC CONNECTION REQUEST messages received by RNC are basis to calculate successrate

RRC CONNECTION REJECT messages sent by RNC excluding redirections + no reply

RRC CONNECTION SETUP COMPLETE wait timer expiry

RRC CONNECTION SETUP COMPLETE messages received by RNC give successfull events.

Reject causes

If supported normal event:

Success

Failure

Attempt


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No reply



CCCH

CCCH

DCCH


L1 synchronizationNBAP: Synchronisation Indication

Lets assume the RL could be established

X

X X

RRC CONNECTION SETUP COMPLETEDCCH

L1 synchronizationNBAP: Synchronisation Indication

X X

One possiblenormal cause

here iscell reselection


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RRC setup failure

RRC Connection Establishments

RRC CONNECTION REJECT messages sent by RNC excluding redirections + no reply

There may be many reasons for the failure:In most cases a dedicated channel will be set up. That means the UE requires Transport, code and Power resources(Admission Control). If not available or if the HW of the RNC or Node B is in overload, the system will send the rejectmessage. In the case of no response from the UE of course no message will be sent.

No response can be due to Cell Reselection (UE asks in new cell), due to radio (no synchronization) or due to UE, Synchronization ok but no response.

The UE has to wait for at least the time stated in the IE "wait time"; will retransmit the request message on this or on another cell of the same frequency for the maximum number of retransmissions of the RRC CONNECTION REQUEST message (N300). If it gets no response, it has to enter the idle mode and has to finish the procedure.

Failure


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Signalling connection

After having established an RRC connection, the UE starts setting up a signalling connection to the core network (CN). The UE sends a message to the RNC which generates a different message to the CN, depending on whether or not there is an active signalling connection to the CN domain. The UE initiates signalling connection establishment to the CN after having established an RRC connection with an RRC:INITIAL DIRECT TRANSFER message. This message triggers the upper layers to initiate a signallingconnection to the core network and to transfer a non-access stratum (NAS) message. TheRNC establishes a signalling connection and forwards the (NAS) message of the RRC:INITIAL DIRECT TRANSFER message to the CN using a RANAP:INITIAL UE MESSAGE message.If the RNC fails in transferring the message to the UE, the CN does not get an indication of the failure. Higher layers are used to repeat the message.There are no KPIs defined for that phase. In case of failures the problems are detected by higher layers.


RadioLink

RABassignment


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Signalling connection

RRC connection

Serving

RRC: INITIAL DIRECT TRANSFER SCCP(CO): CR(RANAP: INITIAL UE MESSAGE)

RRC: DOWNLINK DIRECT TRANSFER

RRC: UPLINK DIRECT TRANSFER

SCCP(CO): DT1 (RANAP: DIRECT TRANSFER)

RANAP and RRC provide transparent containers to transfer NAS messages

SCCP(CO): CC(none)

SCCP(CO): DT1 (RANAP: DIRECT TRANSFER)

CO Connection Oriented CR Connection RequestDT1 Data Type 1 CC Connection Confirm

SCCPConnection

establishment

When the RNC receives an initial direct transferMessage, the RNC will initiate the signallingConnection towards the indicated Core Network


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Radio link setup

Radio link setup procedure is started when a new radio link is needed, for instance, when a new signallinglink is set up or when a handover is performed. The RNC determines the radio link parameters and requests radio link activation at the BTS. In the first radio link setup, the BTS selects the traffic terminationpoint for the communication context and sends the identification of the associated NBAP signalling link to the RNC. The radio link allocation is valid at the BTS until the RNC orders radio link deletion. The procedure also starts the creation or modification of a communication context. Communication context contains information about all activity in one traffic termination point concerning the UE. It is used to associate a set of radio links together at the BTS.

Radio link analyses includes: setup, reconfiguration and deletion


RadioLink

RABassignment

Radio Link setup

Radio Link reconfiguration

Radio Link deletion

The situations that can trigger the radio link reconfiguration procedure are:

-radio access bearer setup (AAL2 setup)

-radio access bearer negotiation (possible AAL2 setup, switching, andrelease)

-radio access bearer release (AAL2 release) . NRT radio access bearer scheduling (AAL2 setup, possible AAL2 switching, AAL2 release).


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Radio Link Setup


NBAP: RADIO LINK SETUP REQUEST [Cell Id, TFCS, frequency, Codes]

NBAP: RADIO LINK SETUP RESPONSE

ALCAP Iub Data Transport Bearer Setup


CELL_DCHCELL_DCH

NODE BRRC CONNECTION REQUEST

Radio Link SetupThe Radio Link Setup

covers ALCAP and NBAP procedures,

which are required if the RRC connection is

established on DCH RRC substate. Layer 1 Synchronisation

NBAP:RADIO LINK RESTORE INDICATION

Radio Link Setup can betriggered by

-RAB Assignment

-Branch additions

-Channel Type Switching

-incoming hard handover procedures.


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Radio Link Setup

Radio link setup can fail, for example, because resources are not available or the controlling RNCcommunication context is already in use. If radio link setup fails, the BTS sends a failure message to the RNC indicating the cause value. The BTS's L3 Common NBAP signalling entity sends the message to the RNC's L3 Common NBAP signalling entity.

Cause are defined in the Node B. examples are..:

-The Node B does not have sufficient DL channelization code.

-No support for UL SlotFormat (i.e. No support for UL SF).

-DL Resources is not available in Node B.

All causes are listed, when the Radio Link Configuration Procedure is discussed

NBAP: RADIO LINK SETUP REQUEST [Cell Id, TFCS, frequency, Codes]

NBAP: RADIO LINK SETUP FAILURE

Node BAdmission Control?


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Radio Link and BitratesAlong with the Radio Link Setup/modification procedure a certain bitrate is established between the UE and the SRNC. According to the TFC settings the bitrate for the service can be found.

The data transfer on transport channels is organized in so called transport block sets (TBS), each carryinga dynamical configured number of transport blocks (TB). In a fixed (but dynamically configurable) time interval TTI (Transmit Time Interval = 10, 20, 40 or 80 ms) one TBS must be transmitted per transportchannel.

The DCH frame protocol (DCH-FP) on Iub provides a carrier frame for the transport block sets and thus thetransport blocks for one or more DCH of a single UE. In the uplink direction there are two interesting fieldsincluded into the DCH-FP UL DATA FRAME. These are:

Quality Estimate (QE): The quality estimate is a coding of the estimated received bit error rate (BER). This estimation is done by the Node B based on channel decoding. The QE can either be the physical biterror rate (after channel coding, before channel decoding) or the transport channel bit error rate (afterchannel decoding). Which one is choosen is configured by the serving RNC.

CRC Indicator Bitmap: Each transport block can be equipped with a cyclic redundancy check (CRC). TheCRC may have size between 0, 8, 12, 16 or 24 bits. Which size for the CRC is applicable per transport block is part of the transport format set of a transport channel.

Example:max. 4 transport blocks 336 bit (320 bit payload), 20 ms TTI = 64 kbps


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Radio Link and Bitrates

Iub Iur or internal

C-RNC S-RNC

Transport Block #1

Transport Block #2

Transport Block #Ki

. . .

Transport Block SetDCH #i

DCH #1

DCH #n. . . ATM AAL2 call

(DCH-FP)ATM AAL2 call

(DCH-FP)

TB #1 DCH #1TB #2 DCH #1

TB #K1 DCH#1. . .

Node BUE

TB #1 DCH #nTB #2 DCH #n

TB #Kn DCH#n. . .

. . .

Quality Estimate (QE)CRC Indicator Bitmap

DCH-FP UL Data Frame

uplink


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Radio Link analyses

Radio Link establishments

RADIO LINK SETUP REQUEST (plus RADIO LINK ADDITION REQUEST sent in case of Soft handover) messages sent by RNC are basis to calculate successrate

RADIO LINK SETUP RESPONSE (plus RADIO LINK ADDITION RESPONSE) messages receivedby RNC give successfull events.

Success

Failure

Attempt

RADIO LINK SETUP FAILURE (plus RADIO LINK ADDITION FAILURE) messages received byRNC and non answered requests give failure events

SF4

SF8

SF16

SF32

SF64

SF128

SF256

SF512

In the Radio Link establishment procedure, the RNC requestsa certain Spreading Factor (SF), which in the end defines thebitrate on the air interface. That means a further distinction in the Request can be made, in which the requests are rankedaccording to the requested SF.


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Radio Link Reconfiguration

NBAP:RADIO LINK RECONFIGURATION PREPARE

NBAP: RADIO LINK RECONFIGURATION READY

AAL2 Setup if needed

NODE B

NBAP:RADIO LINK RECONFIGURATION COMMIT

RRC:Radio Bearer reconfiguration to UE

AAL2 Switching if needed

AAL2 Release if needed

Radio link reconfiguration can fail because of a BTS capability failure or because there are not enough resources, for example. The BTS responds with a failure message to the RNC's prepare message. The failure message indicates the failed radio links and the cause value for the failure.The Node B would respond with the RADIO LINK RECONFIGURATION FAILURE message.

For example additionalRAB requested

NBAP: RADIO LINK RECONFIGURATION REQUEST

NBAP: RADIO LINK RECONFIGURATION RESPONSE

synchronized

Unsynchronized(usually not impl.)


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Radio Link analyses

Radio Link reconfigurations

RADIO LINK RECONFIGURATION REQUEST messages sent by RNC are basis to calculatesuccessrate

RADIO LINK RECONFIGURATION RESPONSE messages received by RNC give successfullevents.

Success

Failure

Attempt

RADIO LINK RECONFIGURATION FAILURE messages received by RNC give failure events

Unknown C-IDCell not availablePower level not supportedDL radio resources not availableUL radio resources not availableRL already activated/allocatedNode B resources unavailableRequested configuration not supportedUnspecified (Radio network layer cause)Invalid CM settingsNumber of DL codes not supportedUL SF not supportedDL SF not supported

Dedicated transport channel type not supportedCM not supportedNumber of UL codes not supportedTransport resource unavailableUnspecified (Transport layer cause)Protocol errorControl processing overloadHW failureO&M interventionNot enough user plane processing resourcesUnspecified (Miscellaneous cause)No reply no message, timeout

RADIO LINK SETUP FAILURE and RADIO LINK RECONFIGURATION FAILURE causes


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RAB assignment

The radio access bearer setup procedure builds a radio access bearer service between the UE and thecore network (CN). The service is negotiated between the UE and CN through the signalling link betweenthe UE and radio access network (RAN) and through the signalling connection between RAN and CN. Once the CN has all the necessary information, it forwards it to the RNC. The RNC analyses theparameters for radio access bearer service and checks whether the resources needed exist. After that, theRNC activates or modifies the physical uplink and downlink radio channels from the WCDMA BTS and creates the transmission channels at the Iub and Iur interfaces according to the reserved radio resources. The RNC then sends the new radio link parameters to the UE on the existing signalling link. Once the UE informs the RNC that it uses the new radio link parameters, the RNC acknowledges the information to theCN and radio access bearer establishment is then complete. The same procedure is also used for addingradio access bearers.

For non-real time (NRT) services, the radio access bearers are created withoutimmediate reservation of radio resources. Instead, radio resources are allocated on demand by using thesignalling link between the UE and the RNC.


RadioLink

RABassignment


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RAB attributes

RABassignment

d 1500 or 1502d 1500 or 1502d 1500 or 1502d 1500 or 1502Max SDU size [octets]

d 16000 -overheadd 16000 -overhead

d 16000d16000Max bit rate [kbps]

BackgroundInteractiveStreamingConversationalATRIBUTES Bearer class

4*10-3,10-5, 6*10-84*10-3,10-5, 6*10-85*10-2,10-2, 5*10-3,10-3,10-4, 10-5, 10-6

5*10-2,10-2, 5*10-3,10-3,10-4, 10-5, 10-6

Residual BER

...

------d16000d16000Guaranteed bit rate [kbps]

------280 max value100 max valueTransfer delay [ms]

10-3,10-4,10-610-3,10-4,10-610-2,7*10-3, 10-3 ,10-4, 10-5

10-2,7*10-3, 10-3 ,10-4, 10-5

SDU error ratio

TS 23.107

fQuality attributes are defined in the RAB set-up and modification message based on the information received via Iu interface (RANAP) from the core network:

Parameters for signalling link

Radio bearer parameters

Transport channels parameters

MAC configuration parameters

Transfer mode for RLC and its parameters

fThe minimum radio resources needed to fulfil the quality requirement should be reserved

fResources are allocated according the bearer class


38

RAB assignment

Signalling link established, MM and CC signalling ..

RAB Assignment Request

RAB Assignment Response

RANAP


AAL2 Setup (real time RAB)AAL2 Setup (CS RAB)

RRC: RB Setup

RRC: RB Setup Complete

CC signalling

RAB Assignment ResponseOne or several responses

Several RABs can be requested

Each RAB requires oneor several Radio

Bearers


39

RAB assignment failure

Signalling link established, MM and CC signalling ..RAB Assignment Request

RAB Assignment Response


AAL2 Setup (real time RAB)AAL2 Setup (CS RAB)

Setting up a radio access bearer can fail, for instance, because the RNC cannot provide the resources requested. If the requested channel type or resource (for example channel rate) indicated in the RANAP:RAB ASSIGNMENT REQUEST message is not available in the RAN, a RANAP:RAB ASSIGNMENT RESPONSE message is sent to the CN. The message contains the appropriatefailure cause.The CN may send a new RAB ASSIGNMENT REQUEST to establish a new RAB or IU RELEASE COMMAND to release all reserved resources.

RRC: RB Setup

RRC: RB Setup CompleteFailure cause

possibletrouble causes


40

RAB assignment analyses

RAB types (examples):

FACH

CS AMR speech 12.2/12.2 Kbps

CS Conversational UDI 64/64 Kbps

CS Conversational UDI 32/32 Kbps

CS Conversational UDI 28.8/28.8 Kbps

PS Conversational 8/8 Kbps

PS Conversational 16/16 Kbps

CS Streaming 57.6/57.6 Kbps



PS Streaming 16/64 Kbps





PS Interactive/Background 64/64 Kbps

PS ........

RAB assignment

Success

Failure

AttemptNumber of a RANAP-message RAB ASSIGNMENT REQUEST sent by the CN to the UTRAN, with a RAB to be set up.

Transmission of a RANAP-message RAB ASSIGNMENT RESPONSE sent by the UTRAN to the CN, with a RAB to be set up.

Transmission of a RANAP-message RAB ASSIGNMENT RESPONSE sent by the UTRAN to the CN, with a RAB failed to setup. (Failure causes are defined in 3GPP TS 25.413)

Failure causes (Examples)

CS - Request superseded

CS - Directed retry

CS - Iu transport connection failed to establish

CS - Transfer syntax error

......


41

RAB for CS

Successful RAB establishments for CS domain per RAB type

failed RAB establishment for CS domain

RAB assignment for CS domain

Attempted RAB establishments for CS domain per RAB type

Transmission of a RANAP-message RAB ASSIGNMENT RESPONSE sent by the UTRAN to the CN, with a RAB to be set up.

Receipt of a RANAP-message RAB ASSIGNMENT REQUEST sent by the CN to the UTRAN, with one or severalRAB to be set up.

Transmission of a RANAP-message RAB ASSIGNMENT RESPONSE sent by the UTRAN to the CN, with RAB failed to set up. For the RAB, which could not be established the failure cause can be found.


42

Call Setup Success Rate


Call setup Success Rate conv

RRC setup successrate x RAB Establishment successrate

In reference to 3GPP TS 25.931, a call setup can be described by the concatenation of the phases

1. RRC connection establishment (cf. 3GPP TR25.93) NAS signaling connection establishment (cf. 3GPP TR25.931, chapter 7.2)

2. -> pure pass-through of Initial Direct Transfer message; success rate=100% assumed

3. RAB establishment (cf. 3GPP TR25.931, chapter 7.6)

Remark that there are additional NAS signaling procedures in the E2E scenario after RAB establishment, which are not further considered within this document. Above call setup phases shall just indicated the phases as long as UTRAN is concerned. In addition, these phases refer to the UE in IDLE mode, but it is possible to have several RAB establishments in the same RRC connection.

Call setup Success Rate voice

Call setup Success Rate conv

Call setup Success Rate ..

In the RRC setup successrate the traffic class canbe distinguished. The Service type can be definedby the RAB Establishment procedure.

KPIs of CSSR for voice and CS data are not quitecorrect since only the QoS class can be selectedper RRC establishment success rate.


43


RRC CONNECTION ESTABLISHMENTS REQUESTS

RRC failures

Succesful RRC CONNECTION ESTABLISHMENTS

NAS failures

RAB assignment attempts

succesful RAB assignments

RAB failures

UE in RRC_Idle


44

CS Call phases

SRB13.6/13.6

Time

RRC: CONNECTION REQUEST

SRB 3.4/3.4

RRC: Radio Bearer Setup

Radio Bearereg. CS AMR speech 12.2/12.2 Kbps

RRC Radio Bearer Release

RRC Connection Release

RRC CONNECTION Establishment

NAS procedures

RAB assignment

Iu Release

Call establishment Ongoing call

NAS procedures

callrelease


45




46

Connection Release

RABRelease

Signallingconnection

release

RRCconnection

release

The UE and CN negotiate about releasing the radio access bearer services, which is assocoiated withone service and provides transmission resources within UTRAN and on the Uu interface. A call releaseis associated with the release of the associated RAB. CN or the RAN may decide to release a radio access bearer service. The RNC sends an indication of the release to the UE and either releases the radio link or modifies the radio link parameters if all radio access bearers are not released. The radio links are also released or modified at the WCDMA BTS, and transmission channels are released both on the Iu and Iub interfaces. Also Iur branches are released or modified if the UE had branches throughanother (drifting RNC). The CN can also request releasing the signalling link if all radio access bearersrelated to the CN are released. Then the signalling connection between the RNC and CN is released. The signalling link between the RNC and UE is also released if the UE has no active connection to another CN.

RadioLink

Release/Modification


47

Signalling Connection Release

Iu releaseRABRelease


release

RRCconnection

release

RLRelease

Signalling connection release can be requested by the CN or by the UE.

The UE can have an ongoing signalling connection to one circuit-switched and one packet-switched core network simultaneously. If one network then requests the release of the signalling connection by running the Iu release procedure, the RNC detects that there is still another signalling connection using the current RRC connection. The RRC connection is not released but the UE is informed that one of the signalling connections is released.


48


IU RELEASE COMMAND

RRC: SIGNALLING CONNECTION RELEASE INDICATION

IU RELEASE COMPLETE

UE has signalling connection to CN 2



IU RELEASE REQUEST

When the UE requests the release of a signalling connection, either the signalling connection release or the RRC connection release procedure follows. If the UE has two signalling connections, the signallingconnection release procedure is done and the UE continues to have a signalling connection to one core network. If the UE has only one signalling connection from before, the RRC connection release procedure is run after which the UE no longer is connected to any core network.


49


IU RELEASE COMMAND

RRC: SIGNALLING CONNECTION RELEASE

IU RELEASE COMPLETE




Normal


50

RAB Release

Iu releaseRABRelease


release

RRCconnection

release

A normal RAB release is initiated by the CN (with some exceptions for PS services and features-Directed Retry for example). When there are several

active RABs for that CN just the RAB is released (radio link will be modified). When the last RAB forthat CN is terminated the RAB(s) and the signalling connection are released by the Iu Release procedure. When there is no other signalling connection to the other CN, the RNC will also release theRRC connection.

Normal

Abnormal The abnormal release of a connection UTRAN originated is indicated either by the RAB RELEASE REQUEST message or the IU RELEASE REQUEST

message transmitted from the RNC to the CN. The RAB RELEASE REQUEST message will be used when the failure occurs in the RAB management as e.g. HW failures,... In any case the UE is still reachable via a RRC connection. The IU RELEASE REQUEST message is used e.g. in case the UE is lost at the air interface. The CN will response either with the RANAP message RAB ASSIGNMENT REQUEST indicating the RAB to be released if another parallel transaction is still ongoing or with the IU RELEASE COMMAND message.

RLRelease


51

RAB Release

There are still ongoing RABs

All ongoing RABsand the signalling

connectionare released

ongoing RABsor RABsand the

signallingconnection

are released

Normal

Abnormal+

Normal

RAB Assignment Request messages ( with cause Release)

Iu Release Comand messages (Cause)

Iu Release Request messages (Cause)

Iu Release Comand messages (Cause)

RAB Release Request messages (Cause)

RAB Assignment Request messages ( RABs to be Released)


52

RAB Release

UE has several RAB active

RAB Assignment Request(Release)


AAL2 Release

AAL2 ReleaseRRC: RB Release

RRC: RB Release Complete

From the Iu interface's point of view, radio access bearer release is always successful. The UE can return a release failure message to the RNC. In this case, the UE uses the old configuration.

UE has remaining RAB active, signalling connection maintained

Normal

Several RABs can be released


53

RAB Releases

RAB releases UTRAN initiated PS

Abnormal RAB releases CN/UTRAN initiated

RAB releases UTRAN initiated

RAB releases UTRAN initiated CS

RAB Release Request messages (Cause) Iu Release Request messages (Cause) messages sent to CN. All causes

Causes:-Failure in the Radio Interface Procedure-Release due to UTRAN generated reason-User inactivity-Iu UP failure-Repeated integrity checking failure-Release due to UE generated signaling connection release-Directed retry-Radio Connection With UE Lost-Normal release-O&M intervention-Unspecified failure-Other causes

All Causes except User inactivity (for Iu PS a normal event, not for IuCS!!!), Directed retry (if supported) and normal release.

Indicates RAB, Call drops

RAB/call drop rate Abnormal RAB releases UTRAN initiated divided bySuccessful RAB establishments (per domain, per RAB type)

RAB releases UTRAN initiated PS

RAB releases CN initiated

RAB releases UTRAN initiated CS


54

RRC connection Release

RABRelease


release

RRCconnection

release

RLRelease

A normal RAB release is initiated by the CN (with some exceptions for PS services and features-Directed Retry for example). When there are several

active RABs for that CN just the RAB is released (radio link will be modified). When the last RAB forthat CN is terminated the RAB(s) the signalling connection will be released by the Iu Release procedure. When there is no other signalling connection to the other CN, the RNC will also release theRRC connection.

Normal

Abnormal An abnormal RAB release is initiated by the RAN. The abnormal release of a connection UTRAN originated is indicated either by the RAB RELEASE

REQUEST message or the IU RELEASE REQUEST message transmitted from the RNC to the CN. The RAB RELEASE REQUEST message will be used when the failure occurs in the RAB management as e.g. HW failures,... In any case the UE is still reachable via a RRC connection. The IU RELEASEREQUEST message is used e.g. in case the UE is lost at the air interface. The CN will response either with the RANAP message RAB ASSIGNMENT REQUEST indicating the RAB to be released if another parallel transaction is still ongoing or with the IU RELEASE COMMAND message.


55

RRC Release

RRC: RRC CONNECTION RELEASE

RRC: RRC CONNECTION RELEASE COMPLETE

Causes:

Normal event

Unspecified

Pre-emptive release

Congestion

Re-establishment reject

Directed signaling connection re-establishment

User inactivity

Other causes

Cause value in RRC Connection Release message shows if the RRC connection was terminated in a normal or abnormal way. Abnormal termination indicates dropped signalling connections, in somecases (correlate with RAB Drops counters on call level) dropped calls = dropped radio bearers.

Especially unspecified release cause is often seen if RRC connection is dropped due to radio link failures or RLC unrecoverable errors.


56

RRC Release

UE has only signalling connection to CN 1

IU RELEASE COMMAND

RL deletion

AAL2 Release

RRC: RRC CONNECTION RELEASE

RRC: RRC CONNECTION RELEASE COMPLETE

From the Iu interface's point of view, radio access bearer release is always successful. The UE can return a release failure message to the RNC. In this case, the UE uses the old configuration.

IU RELEASE COMPLETE

UE in RRC Idle AAL2 Release

Normal


57

Radio Link Release

RABRelease


release

RRCconnection

release

The RNC starts the radio link deletion procedure to release one or more radio links in a communication context. Active set updates,

RRC connection releases and also resets and other error situations such as the BTS and UE beingunsynchronised can trigger this procedure. If the RNC does not receive a response from the BTS before a timer expires, it sends the deletion message again three times. After that, if there is still no answer, the resource manager in the RNC starts recovery actions.

The Radio Link Failure counters count the number of NBAP Radio Failure per cell. A radio link failure does not necessarily indicate a

dropped call or dropped signalling connection. Radio Link Failure are also often seen after successfulhard handover procedures, because the cell is not informed about the fact that UE is handed over to another cell. If subsequently the timer t RL Failure expires before the RNC deletes the established radiolink the NBAP RL Failure is monitored.Typically RL Failures are due to synchronization failure (cause value), but it is also possible to seethem due to invalid compressed mode settings.

RadioLink

Deletion

Radio Link Deletion

Radio Link Failure


58

Radio Link Release

NBAP: RADIO LINK DELETION REQUEST

NBAP: RADIO LINK DELETION RESPONSE

NODE B

AAL 2 Release

NBAP: RADIO LINK FAILURE

AAL 2 Release

IU RELEASE REQUEST

Causes:Synchronization failure

Invalid CM settings

Transport resource unavailable

Control processing overload

HW failure

O&M intervention

Other causes

If there is an ongoing signalling connection


59


2.2.3 GMM Location Updates Authentication Ciphering initialization2.2.4 SMPDP context activation/modification/ deactivation2.3 Procedure related KPI in UTRAN for PS trafficRadio Bearer ControlPS RAB assignment RRC StatesTransport Channel Reconfiguration HSDPA AnalysesHS Radio Link Setup


60

MM proceduresLocationUpdate

CipheringIntegrity protection

Authentication

The Location Update is initiated by the UE when it is switched on (and the UE is configured to register in the CS domain), when The

Location Area changed (based on the Mobility of the UE and on periodic basis, when it has beeninactive during the periodic Location Update timer.

The authentication procedure verifies that the SIM card of the UE is valid. The SIM card contains IMSI/IMUI security keys as well as

other subscriber specific information. The UE sends its MS classmark to the CN. The ciphering capability of the UE is set by the MS classmark which also indicates which integrity protection algorithm (UIA) and encyption algorithm (UEA) it supports. Through the authentication procedure the network is able to verify that the security keys of the UE are valid and correspond to the subscriber information onthe network side. If necessary, the network also requests security parameters from the authentication centre (AC) of the CN. The CN sends back subscriber specific authentication vectors (AV) which consist of information based on the SIM card of the UE. The AV is only valid for one authentication procedure between the UE and the CN.

There are two security modes: ciphering and integrity protection.Ciphering is used to encrypt signals between the user equipment

(UE) and the Radio Network Controller (RNC). This is done to prevent third parties from listening to transmissions. Integrity protection is used to prevent third parties from sending unauthorisedsignalling messages between the UE and RNC. Distribution of the ciphering key (CK) and integrity key (IK) is handled by the authentication and key agreement (AKA).


61

MMLocation Update procedure (Iub)

CR Initial_UE_Message LUREQ

CC

DT1 initiatingMessage AUTREQ

DT1 succesfulOutcome AUTREP

DT1 initiatingMessage CommonID

DT1 initiatingMessage SecurityModeContol

DT1 succesfulOutcome SecurityModeControl

DT1 DirectTransfer LUACC

DT1 DirectTransfer TRCMP opt.

DT1 initiatingMessage IuRelease

DT1 succesfulOutcome IuRelease


62

MM Location updates

LOC UPD REQStart T3210

LOC UPD ACC

Stop T3210 LOC UPD REJ

*HQHULF,06,DWWDFK3HULRGLF

Stop T3210or

HE

AuCMAP procedures

mobility management specific procedureslocation updating procedure

-periodic updating -IMSI attach procedure -generic location updating procedure

In case of supportof NMO 1, the Location Update

would be performed by a GPRS ATTACH

Signalling Connection establishment



63

MM Location update

Location Update

Success

Failure

Attempt &DXVH *HQHULF,06,DWWDFK3HULRGLF

Location Update Request

Location Update Accept

Location Update Reject

)DLOXUHUDWH&DXVHLQLocation Update Reject

IMSI Unknown in HLRPLMN Not AllowedLocation Area not allowedRoaming not allowed in the Location AreaNetwork FailureCongestionIllegal MSGSM Authentication Unacceptable

8QDQVZHUHGQRUHVSRQVH3UREOHPVZLWKVHFXULW\

In the case of Location Update Reject some cause values will result in the total

denial of access to the network.


64

MM Authentication

or

AUTHENTICATION REQUEST

AUTH FAILURE (cause=MAC failure

AUTHENTICATION RESPONSE

or GSM authentication unacceptable)

IDENTITY REQUEST


IDENTITY RESPONSE (IMSI)

The re-synchronisation procedure requires the VLR/MSC/SGSN to delete all unused authentication vectors for that IMSI and obtain new vectors from the HLR

orAUTH FAILURE

cause SYNCH failure



AUTHENTICATION REJECT

8(GRHVQRWDFFHSW1HWZRUN

IMSI/TMSI

When several Requests have been unsuccessfull

the SGSN may request the IMSI

Resynchronisation procedure

or


65

MM Authentication

Authentication

Success

Failure

Attempt

6XFFHVVUDWH

)DLOXUH&DXVH Generated by UEor has to be seen in other messages for example an unansweredAuthentication Request may be ignored because the Radio contact islost with UE.




66

MM Ciphering and integrity protection setup

SECURITY MODE COMMAND

SECURITY MODE COMPLETE SECURITY MODE COMPLETE

SECURITY MODE COMMAND

SECURITY MODE REJECT

Integrity/ciphering information includes key and permitted algorithms

XMAC-I generatedMAC-I and XMAC-Icompared. If match

then returnedacknowledged

MAC-Igenerated


67

MM Service Request

CM Service Accept

( CM service type, CKSN/KSI, MS classmark 2,TMSI or IMSI, priority )

RANAP: Security Mode CMD

CM Service Request

The network can acknowledge the connection request either by CM Service Accept, rejects the Service or by ciphering activation.Unanswered CM service Request messages indicate so usually no trouble.

Abort messages indicate abnormal behaviour, dropped call or here unsuccesfull call setup.

CM Service Rejector

or

Possibleresponses

7KHPRELOHVWDWLRQPD\VHQGD

&06(59,&($%257PHVVDJHDQ\WLPHDIWHUWKHFRPSOHWLRQRIWKH55FRQQHFWLRQDQGQRWDIWHUWKHILUVW&0PHVVDJHHJ6(783LVVHQW

Release ofthe RR connectionSERVICE ABORT

KSI-Key Set Identifier


68

CC

ISUP/H323CC

CC Call Control MOC/MTC

ALERT

CONNECTCONACK

SETUPCPROC

CMSREQ Connection Management Service Request PRES Paging Response

AUTREQAUTREP

CMSREQ

ANSWER MESSAGE

INITIAL ADDRESS MESSAGE

ADRESS COMPLETE MESSAGE

PRESAUTREQAUTREP

SETUPCCONFALERT

CONNECTCONACK

HLR

Pag Type 1


69

CC Call Release

CC

ISUP/H323CC

RELEASE

RELEASE COMPLETEDISC

RELEASERELCOMP

RELEASERELCOMP

DISC


70

CC Call Release

Release

Disconnect

Release Complete

ISUP: REL

ISUP: RLC

Iu Release Command

Iu Release Complete

Iu Bearer Release

Radio Bearer Release

Radio Link Release

Radio Bearer Release Complete


In the case of a droppedcall, the RNC would

send theIu Release Request

message


71

GMM procedures

GPRS attach /detach

Authentication andciphering

Service Request

Routing Area Update

CR Initial_UE_Message ATRQCC

DT1 initiatingMessageSecurityModeContol

DT1 successfulOutcomeSecurityModeControl

DT1 DirectTransfer ATAC

DT1 DirectTransfer ACOM

DT1 initiatingMessage IuRelease

DT1 successfulOutcome IuRelease

RLC

RLSD


72

GMM Attach/Detach

Start T3310

ATTACH ACCEPT

Stop T3310 ATTACH REJECT

:KHQSRZHURIILWPD\EHUHWUDQVPLWWHG

Stop T3310 If P-TMSI and/orTMSI allocatedStart T3350

ATTACH COMPLETE Stop T3350If P-TMSI and/orTMSI allocated

or

DETACH REQUEST

DETACH ACCEPTStart T3321

Stop T3321

DETACH REQUESTor

DETACH REQUEST

DETACH ACCEPT

Detachmobile

originated

Detachnetwork

originated

Attachmobile

originated

ATTACH REQUEST


73

GMM Attach/Detach

GPRS attach

Success

Failure

Attempt 7\SH FRPELQHGRU*356RQO\

)DLOXUHUDWH1RDQVZHUHJ5$1$3FRQQHFWLRQLVUHOHDVHGEHIRUHWKH$77$&+$&&(37LVUHFHLYHG&DXVH Network Failure

CongestionGPRS services not allowedIllegal MS (no roaming contract)Invalid mandatory information.....

ATTACH REQUEST

ATTACH ACCEPT

GPRS detach

Success

Failure

Attempt

ATTACH REJECT

UE initiatedGPRS detach with switching offGPRS detach without switching offIMSI detachGPRS/IMSI detach with switching offGPRS/IMSI detach without switching offNetwork initiatedre-attach not requiredre-attach required

DETACH REQUEST

DETACH ACCEPT (only seen in case of power off)

In many cases the detach mayhappen without procedure

That means as well there is no problemseen in that procedure


74

GMM Authentication

or

AUTHENTICATION AND CIPHERING REQUEST

AUTHENTICATION AND CIPHERING FAILURE

AUTHENTICATION AND CIPHERING RESPONSE

(cause=MAC failure or GSM authentication unacceptable)IDENTITY REQUEST


IDENTITY RESPONSE (IMSI)

orAUTHENTICATION AND CIPHERING FAILURE

cause SYNCH failure



AUTHENTICATION REJECT When several Requests have been unsuccessfull

the SGSN may request the IMSI

Normal case

Several AUTHENTICATION AND CIPHERING REQUESTmessages may be sent, it is repeated if the answerIs not coming within a given time frame.

Resynchronisation procedure


75

GMM Authentication



AUTHENTICATION AND CIPHERING REJECT

initiatingMessage SecurityModeContol

If XRESMS z XRESAC Authentication failed

If Authentication is successful, ciphering is initiated

AUTHENTICATION AND CIPHERING

Success

Failure

Attempt AUTHENTICATION AND CIPHERING REQUEST messages sent by SGSN

AUTHENTICATION AND CIPHERING RESPONSE messages received by SGSN

AUTHENTICATION AND CIPHERING FAILURE messages received by SGSN

Authentication and CipheringFailure is a unidirectional errormessage that has no impact on

Auth. & Ciph. Success Rate

or


76

GMM Routing Area Updates

Routing Area Update Request( Update type: RA updated or combined RA/LA updated,

GPRS ciphering key sequence number,old RAI, MS radio access capability )

Authentication

Routing Area Update Accept( Update result,

Period RA update timer, current RAI, optional: allocated P-TMSI, P-TMSI signature,

Receive N-PDU number )

Routing Area Update Complete

Start T3330(= 15 s)

Stop T3330 Start T3350 (= 6 s) only when P-TMSI and/or Receive N-PDU numbers were allocated

Stop T3350

Routing Area Update Accept


77

GMM Routing Area Reject

Routing Area Update Request

( Update type: RA updated or combined RA/LA updated, GPRS ciphering key sequence number,old RAI, MS radio access capability )

Authentication

Routing Area Update Reject( GMM cause )

IMSI unknown in HLRIllegal MSIllegal MEGPRS services not allowedGPRS services and non-GPRS services not allowedMS identity cannot be derived by the networkImplicitly detachedPLMN not allowedLocation Area not allowedRoaming not allowed in this location areaGPRS services not allowed in this PLMNNo Suitable Cells In Location AreaMSC temporarily not reachableNetwork failureMAC failureSynch failureCongestionGSM authentication unacceptableNo PDP context activatedretry upon entry into a new cellSemantically incorrect messageInvalid mandatory informationMessage type non-existent or not implementedMessage type not compatible with the protocol stateInformation element non-existent or not implementedConditional IE errorMessage not compatible with the protocol stateProtocol error, unspecified

GMM cause values

The GMM cause gives the reason for the reject, not all values are necessarily implemented.


78

GMM Routing Area Updates

Routing Area Updates

Success

Failure

Attempt Routing Area Update Request messages received from UE

Routing Area Update Accept messages sent by SGSN

Routing Area Update Reject messages sent by SGSN

MS identity cannot be derived by the network

Implicitly detached

GPRS services not allowed in this PLMN

Network failure

Protocol error, unspecified

Important GMM rejectcause values


79

GMM Service Request

( CKSN, P-TMSI, PDP context status, service type= paging response | data | signalling )

Service Request

Service Accept

RANAP: RAB AssignmentRequest

RRC:Radio Bearer Setup

RANAP: RAB AssignmentResponse

RRC:Radio Bearer Setup

Complete

Service Reject The main cause for the Service Rejectmessage is Misalignment between theUE and SGSN. While UE thinks that thePDP context is still active the SGSN has already released the PDP context.

or

By sending a Service Requestmessage the UE request the setupof a RAB for a PS data call. SomeService Request message arepaging responses. This is used to calculate a PS Paging SuccessRate.


80

GMMService Activation Analysis

Service Activation Analyses

Success

Failure

Attempt Service Accept messages received from UE

Service Accept messages sent by SGSN

Service Reject messages sent by SGSN

Paging Responses

others

Can be used to calculate PS paging successrate

Difficult to calculate successrate, because the message is not allways found

Mainly to detect PDP errors, the PDP has been implicitly deactivated by network.


81

GPRS Session Management

(TYPE=SIGNALING)

Service Request



COMMON IDSECURITY MODE COMMAND

SECURITY MODE COMPLETEACTIVATE PDP CONTEXT REQUEST

RANAP: RAB AssignmentRequestRRC:

Radio Bearer SetupRRC: Radio Bearer

Setup Complete RANAP: RAB AssignmentResponseACTIVATE PDP CONTEXT ACCEPTACTIVATE PDP CONTEXT REJECT

or GTP-C procedures

( TI, NSAPI, requested QoS, requested PDP address, APN )

GTP Tunnel setup

CREATE PDP CONTEXT REQUEST

CREATE PDP CONTEXT RESPONSE


82

SM other procedures

ACTIVATE SECONDARY PDP CONTEXT REQUEST

ACTIVATE SECONDARY PDP CONTEXT ACCEPT( TI, NSAPI, requested QoS, linked TI, TFT)

TFT Traffic Flow Template

MODIFY PDP CONTEXT ACCEPTMODIFY PDP CONTEXT REQUEST

MODIFY PDP CONTEXT ACCEPTMODIFY PDP CONTEXT REQUEST

UPDATE PDP CONTEXT REQUEST

UPDATE PDP CONTEXT RESPONSE

DELETE PDP CONTEXT REQUESTDELETE PDP CONTEXT ACCEPT

DELETE PDP CONTEXT REQUEST

DELETE PDP CONTEXT ACCEPT

DELETE PDP CONTEXT REQUESTDELETE PDP CONTEXT ACCEPT


83

SMPDP context Analyses

PDP context activations

Success

Failure

Attempt ACTIVATE (SECONDARY) PDP CONTEXT REQUEST messages received from UE

ACTIVATE PDP CONTEXT ACCEPT messages sent by SGSN

ACTIVATE PDP (SEONDARY) CONTEXT REJECT messages sent by SGSNSM cause information element is to indicate the reason why a session management request is rejected.

Operator Determined BarringInsufficient resourcesMissing or unknown APNUnknown PDP address or PDP typeUser authentication failedActivation rejected by GGSNActivation rejected, unspecifiedService option not supportedRequested service option not subscribedService option temporarily out of orderRegular deactivationQoS not acceptedNetwork failureReactivation requiredSemantic error in the TFT operationSyntactical error in the TFT operation

Unknown PDP contextPDP context without TFT already activatedSemantic errors in packet filter(s)Invalid transaction identifier valueSyntactical errors in packet filter(s)Invalid transaction identifier valueAPN restriction value incompatible with active PDP contextMessage type non-existent or not implementedMessage type not compatible with the protocol stateInformation element non-existent or not implementedConditional IE errorMessage not compatible with the protocol stateProtocol error, unspecified

.

The SM cause gives the reason for the reject, not all values are necessarily implemented.


84




85

Radio Bearer Control

384 kbps 128 kbps 64 kbps

Radio Bearer Control decides about which resources are allocated to the UE. This function manages the bit rate management of the radio link to the source bit rate and quality of service requirements. The Radio Bearer Control function controls the use of resources of one UE. If a UE has variable rate services (Non Real Time Bearers) active, for example a web browsing session, then its demand for air capacity changes over time. The RB control function optimizes the use of radioresources, by assigning sufficient capacity to the UE when necessary or releasing itwhen the data rate is low, so that it can be used for other users.this managed by

. transport channel type switching (CTS) function.

The CTS performs transitions between dedicated and common channels.

The Bit Rate Adaptation function (BRA).

BRA performs the reconfiguration of the data rates for packet switching radio access bearer. This improves the dedicated radio resource usage and the user quality of service by adapting the necessary rate according to each service


86

PS RAB assignment

ACTIVATE PDP CONTEXT REQUEST

RANAP: RAB Assignment RequestUL/DL 64/384 kbps requested

RRC: Radio Bearer Setup

RRC: Radio Bearer Setup Complete RANAP: RAB Assignment Response

ACTIVATE PDP CONTEXT ACCEPT (UL/DL 64/384 kbps negotiated)

(UL/DL 64/384 kbps requested)

GTP Tunnel setup

NAS Procedures

CELL_DCH

CELL_DCH

No DCH for PS-RB isallocated, only the RB is setup

RRC: Measurement Control [Handover meadurements]

RRC: Measurement Control [Traffic volume meadurements]

The traffic volume measurement parameters (RLC buffer level, reporting

criteria, etc.) are sent to UE


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PS services in UTRANWhen a signalling connection to on CN exists, there is an RRC connection and the UE is inUTRAN connected mode. In UTRAN connected mode, the position of the UE is known on cell or UTRAN Registration Area (URA) by the Serving RNC. The UE leaves the UTRAN connected mode and returns to idle mode when the RRC connection is released or at RRC connection failure. When the UE position is known on cell level, it is either in CELL_FACH, CELL_DCH or CELL_PCH state. Not all substates are necessarily supported.

RRCconnected

RRC idle

CELL_DCH

CELL_PCH

CELL_FACH

URA_PCH


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RRC statesThe four packet data transfer states are needed in order to efficiently manage non-real time (NRT) radio access bearer (RAB) users. This is necessary in order to use the available radio resources efficiently and also in order to conserve UE battery life within the UTRAN. The channel typededicated or common) selection for non-real time radio bearer depends on current status of bearer allocations. Several radio bearers may be assigned for one UE and they are multiplexed into one radio link on L1. The assigned bearers can be real-time or non-real time radio bearers. If real-time bearers are assigned to the UE, then dedicated transport channel (DCH) is always used. If only non-real time bearers are assigned to the UE, then using RACH and FACH channels is also a possibility. RAN shall have the possibility to dynamically, during an RRC connection, switch between common and dedicated transport channels.

RRCconnected

CELL_DCH CELL_FACHURA_PCHCELL_PCH

RRC connectionNo Radio Beares allocated

NRT Radio Bearersallocated

RT Radio Bearesallocated

NRT Radio Bearesallocated

RT+ NRT Radio Bearesallocated

RRC connectionestablishment

RRC connectionrelease


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RRCconnected

RRC state transitions

CELL_DCH

CELL_PCH

CELL_FACH

URA_PCH

RRC idle

The CELL_DCH state is characterized by the allocation of a dedicated transport channel to the UE. (When NRT DCH(s) or RT RAB are allocated)

In the CELL_FACH substate the UE monitors a forward access channel (FACH). In this state, the UE is able to transmit uplink control signals and may be able to transmit small data packets on the random access channel (RACH).

The RRC idle state is characterized that the UE is not known in UTRAN.

In the CELL_PCH substate the UE listens to the PCH transport channel. If the network wants to initiate any activity, it needs to make a paging request on the PCCH logical channel in the known cell. The UE initiates a cell update procedure when it selects a new cell or for data transfer.

In the URA_PCH substate the UE listens to the PCH transport channel. If the network wants to initiate any activity, it needs to make a paging request on the PCCH logical channel in the known URA. The UE initiates a URA update procedure when it selects a new cell.


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RRC idle

CELL_DCH

CELL_PCH

CELL_FACH

URA_PCH

Dedicated channel (DCH) establishment


Last NRT DCH is releasedno RT RAB exist




Many cell updates

Inactivity Data transferData transferInactivity

The RRC connection is iniated by the UE, the decision upon the substate is done in the Serving RNC, mainly based on data volume and activity for the UE. This picture does not show the procedures!!!


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CELL_DCH

CELL_PCH

CELL_FACH

URA_PCH

Radio Bearer ReconfigurationCell Update (radio link failure)

CELL_FACHRadio Bearer Reconfiguration

Radio Bearer Setup CELL_DCH

CELL_FACHPhysical ChannelReconfiguration

Cell Update Confirm

CELL_DCH CELL_PCHRadio Bearer Reconfiguration

CELL_PCH

CELL_FACH

URA_PCHCELL_DCH

URA_PCH

CELL_FACH

CELL_FACH

Cell Update

URA update Cell Update

Pysical Channel ReconfigurationCell / URA Update Confirm

Radio Bearer Reconfiguration

This picture show the procedures, which actually may be used to switch between the states, theymay be initiated by UE or RNC. Not all procedures are necessarily implemented.


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NBAP: RADIO LINK DELETION REQUEST

ALCAP Iub bearer release

NODE B

UE in CELL_DCH, no RT RAB activeinactivity timer

Expires. RNC decidesto move UE to CELL_FACHRRC: RADIO BEARER RECONFIGURATION

UE in CELL_FACHRRC: RADIO BEARER RECONFIGURATION COMPLETE

NBAP: RADIO LINK DELETION RESPONSE

RRC: RADIO BEARER RECONFIGURATION FAILURE


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NODE B

UE in CELL_FACH, no RT RAB active

Measurement Report received and/or DL capacity

need is detected by MAC

RRC: RADIO BEARER RECONFIGURATION

UE in CELL_DCH

RRC: RADIO BEARER RECONFIGURATION COMPLETE

UL capacity need isdetected by MAC

RRC: MEASUREMENT REPORT [Traffic Volume Measurements]

NBAP: Radio Link Setup procedure

UE moves to CELL_DCH

OPTIONAL

RRC: RADIO BEARER RECONFIGURATION FAILURE


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Cell update

NODE B

UE in URA/CELL_PCH

RRC: Cell Update Confirm [New C-RNTI]

UE in CELL_FACH

DL capacity need isdetected by MAC

UE moves to CELL_FACH

RRC: RRC RELEASE REQUEST

RRC: Paging Type 1 [U-RNTI]

RRC: Cell Update [Cause: e.g. Paging Response]

RRC: UTRAN Mobility Information Confirm

RRC: Paging Type 1 [U-RNTI]

or

If no response


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RRC state management analysesTransformations from CELL_DCH

Success

Failure

Attempt

CELL_PCH

CELL_FACH

URA_PCH

CELL_PCH

CELL_FACH

URA_PCH

CELL_PCH

CELL_FACH

URA_PCH

-FAILURE message is received-causes: no resources, decoding problems,

-No response from UE-another procedure has been initiated

Depends on procedure, the need for UL/DL Data, inactivity, ... the corresponding message is found on Iur, Iu, Uu

The corresponding response is found


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RRC state management analysesTransformations from CELL_FACH

Success

Failure

Attempt

CELL_PCH

CELL_DCH

URA_PCH

CELL_PCH

CELL_DCH

URA_PCH

CELL_PCH

CELL_DCH

URA_PCH

Transformations from CELL_PCH

Success

Failure

Attempt

CELL_FACH

CELL_FACH

CELL_FACH


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Transport ChannelReconfiguration

ACTIVATE PDP CONTEXT REQUEST

ACTIVATE PDP CONTEXT ACCEPT (UL/DL 64/384 kbps negotiated)

(UL/DL 64/384 kbps requested)

NAS Procedures

CELL_DCH

RANAP: RAB Assignment RequestUL/DL 64/384 kbps requested

RANAP: RAB Assignment ResponseGTP Tunnel setup

The PDP is active, now the RNC decides about the RRC substate and a about which Radio Bearersare allocated, mainly based on Traffic volumes, but of cource other issues, like Traffic load in the cell, used power,...

RB-Type 1: UL/DL 64/64 kbps assigned



't1

't2

The dedicated channel upgrade/downgradeprocedure is performed in CELL_DCH state and it requires the reconfiguration of radio link, transmission and RNC internal resources.

The decision about the rate is based on the output of admission control in terms of initial rate or minimum rate. If initial rate will be not accepted by admission control then the minimum rate will be used by admission control.


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NODE B

UE in CELL_DCH, RAB active

RRC: TRANSPORT CHANNEL RECONFIGURATION

UE in CELL_DCH, RAB active

RRC: TRANSPORT CHANNEL RECONFIGURATION COMPLETE

NBAP: Radio Link modification procedure

RRC: TRANSPORT CHANNEL RECONFIGURATION FAILURE

or


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Transport Channel Reconfiguration

Success

Failure

Attempt TRANSPORT CHANNEL RECONFIGURATION messages sent from RNC

TRANSPORT CHANNEL RECONFIGURATION COMPLETE messages sent by UE

TRANSPORT CHANNEL RECONFIGURATION FAILURE messages sent by UE or no response

C 2 6270 Call-Connection Analyses 002 KH

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Transcript of C 2 6270 Call-Connection Analyses 002 KH