47936945 BSS System Description Alcatel System

8 Operat Operations ions & Mainte Maintenance nance

8.2 8. 2

O&M O& M Co Comm mmun unic icat atio ion n Me Mech chan anis ism m This section explains how: "

O&M functions communicate within the BSS

"

Messages are passed amongst the OMCR, BSC, BTS and the TSC.

The communication mechanism transports alarm, event, audit and operator command messages throughout the BSS.

8.2 .2..1

O&M Command Flows OMCR/BSC

OMCR information is passed between the OMCR and the BSC, using the CMISE protocol. The CMISE protocol is the OSI network management protocol over X.25. The majority of OMCR related commands are based on the four message scenarios: " " " "

M_ACTION M_ACTIONcnf M_EVENT_REPORT M_EVENT_REPORTrsp.

These message scenarios are shown in Figure 67. The OMCR requests an action from the BSS via the CMISE command M_ACTION. Specific commands are used for each action. For example, to demand an alarm list, the OMCR issues the command: –

M_ALARM_LIST

The word ACTION in the table above and in the illustrations which follow is replaced by the real command, in this case ALARM_LIST. OM C  R

BSC

ACTION

Figu Fi gure re 67

3BK 02974 AAAA TQZZA Ed. 07

Examp Exa mple le:: Me Messa ssage ge Fl Flow ow Us Usin ing g CM CMISE ISE

191

/ 240

8 Operat Operations ions & Mainten Maintenance ance

BSC/BTS/TSC

The O&M protocol between the BSC, the BTS and the TSC uses the GSM standard 08.59 (O&M signalling transport layer) header. This header handl handles es the sequencing sequencing and encapsulation encapsulation of data. The O&M command/message is stored with its channel identity, reference and parameters. For more information about the alarm and measurement observation parameters, refer to the BSS Alarm Dictionary and the Opera Operations tions & Mainte Maintenance nance Reference Guide. The command sequence between the BSC and its corresponding BTSs and TSCs uses a similar command flow to the CMISE. This is shown in Figure 68. OM C

BSC

BTS

ACTION

Figu Fi gure re 68 Note

192

/ 240

Exam Ex ampl ple: e: BS BSC C Co Comm mman and d Fl Flow ow

There are also other, less common message exchanges. They are based either on one pair of the four message sequence, or several replies to the original M_ACTION pair, i.e. M_ACTION and M_ACTIONcnf.



8.2. 8. 2.2 2

Spon Sp onta tane neou ouss Me Mess ssag age es Messages such as alarms and event changes are spontaneous. Alarms are generated due to changes in the operation of the system. They are not in response to an action invoked by the OMCR. This means that there is no M_ACTION pair. There are two message scenarios for spontaneous messages: "

M_EVENT_REPORT which is an event_report (i.e. from the BSC to the OMCR)

"

M_EVENT_REPORTrsp which is a response to the event_report (i.e. from the OMCR to the BSC).

Alarms Alarmstart and alarmend commands use two messages. The alarm arrives at the OMCR as an alarm report. The OMCR sends an acknowledgement.

Event Changes


Event messages are spontaneous. They inform the OMCR of changes to the SBL state. See Section 8.3.1 for further information concerning events.

193 / 240

8 Operations & Maintenance

8.3

Alarms The BSS generates alarms to signal a change in the behavior of a particular function within the system, such as a potential problem or a confirmed failure in the system. This section describes the alarm generation process. It describes the alarms and their effects on the system.

8.3.1

Alarm Generation When an Alarm is generated, it is indicated as either: "

Fault (begin or end) If a fault arises, the related alarm is stored in an AlarmsInForce List (AIFL) in the relevant BSS unit, unit, and also in the OMCR. The alarm begin message signals that a particular system activity has stopped due to an error error.. When the error is corrected, an alarm end message is sent to indicate that the condition no longer exists, and the alarm is taken out of the AIFL.

"

Event An Event occurs when an unexpected situation situation arises during system operation.

Alarms can be generated as a result of previous alarms or events which influence other parts of the system. For example, when the CU produces an alarm to signal an internal fault, the FU and the Radio Signalling Link produce alarms to signal that no information is being received from f rom the CU. Fault correlation and filtering actions are performed by the O&M modules in each unit, so that a single fault is sent as an alarm. In the case of the faulty CU, an alarm is sent signalling a CU fault. In this example, the loss of the RSL link is signalled from the BSC but is not correlated. Correlation

Correlation refers to the collection and analysis of all available fault indications for a particular problem. Fault correlation is performed to define where and why the fault occurred. An example of correlation is as follows:

194

/ 240

1.

When several boards in the BTS report clock problems, these reports are correlated by the OMU.

2.

The 'clock generator is faulty' alarm is sent to the OMCR.



Filtering Alarms are filtered to minimize the number of fault alarms reported and displayed to the operator. operator. Alarms are displayed in order of severity.

Persistency A fault is signalled only if there is no recovery after the timer expiration. For example, in the case of a LAPD failure of an RSL link, an alarm is sent only if the LAPD link has not recovered before the persistency timer has expired.

AlarmsinForce

8.3.2

Each BSS component keeps an AIFL, so that the system knows that an alarm has begun. This list ensures synchronization of alarms throughout the BSS components. This makes the alarm situation visible at all times. The OMCR OMC R also keeps track of all the AIFLs for each BSS component.

BSC Alarms BSC detects alarms on the Abis and A trunk via the TCU and the DTC. It also detects alarms from each functional unit of the BSC.

Heartbeat

The active SCPRA creates a daisychain map of all the processors in the BSC. Every ten minutes, the SCPRA S CPRA sends the map to the next processor. processor. This processor sends the information to the next processor in line, until the SCPRA receives the daisychain map. The daisychain map can be modified by an intermediary processor when that processor cannot send the map to the next processor in line. In this case, the intermediary processor skips the processor and removes that processor from the daisychain map. When the SCPRA receives the map with the same processor missing twice in a row row,, it tries to recover the processor. processor. If the processor cannot be recovered, the SCPRA places the processor in the Faulty (FL ( FLT) T) state. The SCPRA signals the event change and alarm to the OMCR as follows: "

If a TCU fails, recovery only takes place to ensure BCCH functionality.

"

If a DTC fails, the BSC tries to inform the MSC, so that MSC is aware that the SS7 link is now out of service. This implies: D D


The loss and, if possible, the changeover of the SS7 The blocking of circuits.

195

/ 240


Telecom Link or Trunk Failure

The TSC supervises its trunks and their links between the TSC, BTS, and MSC. Failure of the Abis interface is signalled to the BSC by all of the RSLs of the associated BTS. A single RSL failure reflects the status of the corresponding LAPD and FU FU.. All A interface faults are controlled by the TSC and the the MSC. However they are also monitored by the BSC, in order to define the status of each "endtoend" Atrunk. Figure 69 shows RSL fault correlation on the Abis interface.

Note

The BTS_TEL SBL describes the status of the GSM defined BTS telecom functions. Its state is defined by operator commands, and correlation of the LAPD RSL states or of the different CUs.

Faul Fa ultt St Star artt

CPR CP R In Info form rmed ed

RSLL St RS Stat ate e Ch Chan ange ge Alarm begin BTS_TEL

RSL-1 Per ersi sist sten ency cy

ACTIVE

Corr Co rrel elat atio ion n

INACTIVE Fault Start RSL-2

Fault Start RSL-N (last RSL)

Figur Fi gure e 69

196

/ 240

RSL Cor Correl relati ation on on the Abi Abiss Int Interfa erface ce



The BSC monitors the A interface faults as follows: 1.

The BSC detects the first LAPD RSL link failure of the BTS. The BSC starts a persistency timer timer.. It puts the SBL of the RSL into a Maintenance Seized (MSD)Auto state while the following actions occur: D

D

D

Note

Software Failure

The Replaceable Items (RIT (RITs) s) are now in the Software Out of Service (SOS) state. This is because the Radio Time Slot (RTS) belonging to the RSL still functions, but cannot communicate with the BSC. Telecoms resources are blocked to prevent new activity at the BSC end of this link. The RSL SBL is put into the FLT state, reflecting the loss of the RSL.

2.

The persistency timer expires and the Common Processor (CPR) is informed of the fault. If the link recovers during the persistency period, nothing is reported. Otherwise a correlation timer starts and waits for further RSL link failures belonging to the same BTS.

3.

Once the correlation timer expires the BSC informs the OMCR of each RSL failure by changing its state to the FLT state.

4.

The OMCR is then informed about the state of the BTS_TEL. If all the RSLs belonging to the BTS have failed, then an alarm is sent to the OMCR signalling the loss of the cell. When an AIFL begins it puts the BTS_TEL in an FLT FLT state.

5.

When the BSC detects a DTC failure, the BSC puts the DTC SBL in the MSDAuto state. This prevents new MS originated calls from using the failed link of the DTC. It then changes the DTC SBL to the FLT state. This is then signalled to the OMCR. The TSC also detects a failure of the Ater link and signals the failure to the OMCR.

The A channel is allocated only by the MSC. Software throughout the BSC detects error and alarm conditions. It reports these conditions to the alarm handling software. The alarm handling software performs persistency persistency,, filtering and correlation actions on the received alarm indicators, and determines the required action (e.g. to isolate a faulty SBL). Figure 70 shows an example alarm report.


197

/ 240


If one or more RSL links remain for the failed BTS, an event change is sent. An AIFL begins putting the BTS_TEL in a Faulty In Traffic (FIT) state, as some channels for that cell are in operation. The BSC marks the cell as degraded in service and reconfigures the BTS. Alarm Class, Number and Name ==Alcatel 900 Event-ti Even t-time me Event-type Obje Ob ject ct-c -cla lass ss Object-instance

Alarm Type, Type, Number and Name

BSS REPORT==============================125=== : 1995 1995:11: :11:15 15 10:4 10:43:42 3:42:09 :09 Job-id Jobid : 44 : UNSOLICITED ALARM REPORT : SB SBL L : unit-type : BTS nbr : 1 : SBL-type : FU nbr : 2

Alarm-info : alarmala rm-cla class ss alarmala rm-typ type e alarm-nbr alarm-cat alar al armm-co cond nd

: : : : :

07 – FRA FRAME ME UNI UNIT T 006 – BOT BOTH-B H-BSISI-LIN LINKS KS 1 PMA BEGI BE GIN N

Prev-state

:

IT

Cur urrr-st stat ate e

:

FOS

Rit-list unit-type BTS BTS BTS BTS BTS BTS BTS BTS

nbr 1 1 1 1 1 1 1 1

Defence-action

:

Suspected-rit unit-type BTS Addition-data

:

Addition-data

:

Addition-data

:

Flt-loc-unit-type Flt-loc-unit-nbr

: :

rack 2 2 2 2 2 2 2 2

shelf 3 3 3 3 3 3 3 3

slot 5 21 33 15 17 19 25 27

rit-type FUPS FUCO FUIF CECC CDCC CDCC DMDT DMDT

shelf 3 6 48 0 51 255 0 0 0 1 0 8 255

slot 33 35 0 2 130 0 1 0 0 0 0 0 255

rit-type FUIF 8 223 0 0 0 0 0 0 8 0 255 255

NO ACTION

nbr 1 223 2 61 48 0 0 0 0 1 0 0 255

rack 2 53 0 42 1 255 1 0 0 0 8 0 255

BTS 1

Timestamp : 1995:11:15 10:43:42:09 ===========================================================================

Suspect RIT

Figu Fi gure re 70

198

/ 240

Additional information

List of RITs belonging to SBL

Exam Ex ampl ple: e: Al Alar arm m Re Repo port rt



8.3.3

BTS Alarms Alarms in the BTS are tracked by the OMU. OMU.

G1/G2 Alarm Buses

BTS A9100 Alarm Buses

In G1 and G2 BTSs, the OMU has a Q1 interface to the CUs, Master Clock Unit (MCLU), External Alarm Collection Board (EACB), and Frequency Hopping Unit (FHU) modules in the system and a Token Bus interface with all of the FU modules. In the BTS A9100, the BSII provides the OMU with an interface to the TRE functional unit, and to the ANx and TRANS & CLOCK functional entities, which have their own onboard controllers. The BCB provides an interface to all the functional f unctional entities in the BTS.

Q1 Interface (G1/G2 BTS)

On the Q1 interface, a system of double polling takes place. The OMU polls each subsystem individually to find out if there is an error.. If there is an error, error error, the OMU demands an error report from that board. Normally, Normally, the information from the error report is used as an alarm or an event notification.

Token Bus Interface (G1/G2 BTS)

On the Token Token Bus interface, the OMU is informed by the FU about the type of error that has occurred. The OMU sends the alarm information to the BSC.

BSSI (BTS A9100)

On the Base Station Internal Interface, each module spontaneously reports errors to the OMU OMU,, which processes the report as an alarm or an event notification.

BCB (BTS A9100)

The Base station Control Bus operates in a master/slave configuration where the SUM functions as Pilot (master) and the functional entities function as Terminals (slaves) in normal conditions. The OMU collects alarm information on the BCB and sends it to the BSC.

Alarm Collection

The mechanism for BTS alarm collection on all buses is as follows: 1.

The alarm is added to the AIFL.

2.

The OMU enters alarm information in a queued buffer buffer.. In this way,, alarms are queued even if the link between the BTS and way the BSC is temporarily unusable. If the buffer becomes full (over 100 messages): D D


All fault/state change messages are deleted No more messages are sent until a state and alarm audit takes place to synchronize the BSC and the OMCR. OMC R. An audit BTS request is transmitted on a regular basis until an audit occurs.

199

/ 240


3.

The alarm messages are transmitted at level 3, over the Abis link to the BSC. The message format uses the GSM standard 08.59, which contains the alarm information. This is described in the BSS Alarm Dictionary and the Opera Operations tions & Maintenance Reference Guide Guide..

4.

The message is sent to the System Common Processor Type Type A (CPRA), where it is date and time stamped.

5.

8.3.4

The BSC performs one of two activities: D

If possible, it processes the alarm, performs an action and sends a different alarm/event to the OMCR, OMC R, via the alarm queue

D

Otherwise, it retransmits the message to the OMCR, via the alarm queue.

6.

The message is put in the alarm queue. If the queue overflows, the BSC performs an AlarmsinForce Alarms inForce audit on all the modules in the BSC. This signals that information was received and lost when the queue overflowed, and that resynchronization is required.

7.

The OMCR receives the alarm over the CMISE link. It logs the alarm in the AIFL and on the console.

TSC Alarms TSC O&M activities are similar to those performed by the BTS. The TSC has a Q1 interface to the transmission equipment. A system of double polling occurs on the Q1 interface: "

The first poll checks if there was a change in states

"

The second poll occurs only if the state has changed, in order to obtain more information about the changes.

The loss of the link between the BSC and TSC is the only indication the TSC receives that a failure has occurred.

200

/ 240



8.4

Status Changes Status changes show the interaction between: " " "

SBL state statess Operator commands The status of funct functional ional units.

This section describes possible changes in SBL status, and the effect such changes have on the rest of the system. It lists the operator commands that can be used in each SBL state. The impact of operator commands on the operation of the unit and on its SBL state are also described.

8.4 .4.1 .1

Pha hase sess of Boa oard rd Op Ope era rattio ions ns A functional unit (i.e. 1 SBL = n RIT RITss = n boards) such as a TC passes through several states before becoming operational: Tab able le 16


Func Fu ncti tion onal al Un Unit it St Stat ates es

State

Action

Boo oottstrap

Boot otsstrap enables the functiona nall unit to be initialized, and to perform functions including self tests and downloads.

Selftests

Extensive selftests tak ake e pla lacce to ensure tha hatt the functional unit is physically functional.

Softwa Sof tware re Dow Downloa nload d

Software Softwa re dow downloa nload d of pro progra grams ms occ occur ur if the SBL is able to load software. software.

Soft So ftwa ware re St Star artt

Soft So ftwa ware re st star arts ts an and d is in op oper erat atio ion. n.

Tests

Nondestructive selftests (memory checksum, program id verification, compatibility, etc.) are initiated to ensure that the hardware and software can function as a complete unit.

Download Configuration

This function ensures the download of configuration data. It also ensures synchronization.

Start

The board is now functional.

In Ope perrat atio ion n

The bo boar ard d is fu func ncttio ioni ning ng,, but co cou uld be in a st stat ate e of degraded service. Degraded service can be due to hardware/software problems. The board can still operate, but at less than maximum service or reliability.

201 / 240


8.4 .4.2 .2

Stat St ate e Ch Chan ang ge Ope pera rattio ions ns Maintenance commands ensure the control of system entities and functions, either by returning them to a known active mode, or by deactivating them. Figure 71 shows the tasks performed for each maintenance command. The tasks are shown as they occur in the system boards during initialization phases. Tasks performed by SBL as a result of each command

COMMANDS

STATES

WAIT

DISABLE RESET

OPR,FOS,FLT

Bootstrap

(loadable units only) INIT

SelfTests

SW Download MSD,, MSDauto MSD RESTART

SW Start

(loadable units only) Tests Download Config Function Start

IT, FIT, WTC

Operational

Figu Fi gure re 71

Stat St ates es an and d Pha Phases ses of Bo Boar ard d Op Oper erat atio ion n The operational states show how the RESET, INIT, DISABLE and RESTART REST ART commands affect functional units and its SBL state. Note

202 / 240

The status of a board (active, inactive or faulty) has a direct relation with the state of the SBL.



8.4 .4..3

States In Traffic The following states are all active SBL states: IT

An SB SBLL in th the e In Tra raff ffic ic (I (IT) T) st stat ate e pe perf rfor orms ms al alll it itss functions. It is set into traffic by the operator and no problems are detectable.

FIT FI T

An SB SBLL in th the e FI FIT T st stat ate e pe perf rfor orms ms it itss fu func ncti tion onss in a degraded mode. A RESET or RESTART RESTART can be performed as a recovery measure. The disabled SBL states FLT and Operator Out of Service (OPR) can exist only when a board is:

WTC

D

Not operational and is waiting for a bootstrap start

D

Already in selftest mode.

An SBL in the Wait Wait Traffic Traffic Clear (WTC) state waits for the traffic to clear (i.e. a transitional state). When there is no traffic, the SBL state changes to OPR. This SBL state signals that no new traffic will be accepted by this SBL/equipment. The WTC state is used in two ways: D

D

EF

As a time out action in cases where existing traffic can be active until the timer expires To wait until all traffic disappears before changing the state.

An SB SBLL in th the e Ex Exte tern rnal al Fa Faul ultt (E (EF) F) st stat ate e ca cann nnot ot pe perfo rform rm it itss function because another cooperating item is not operational.

Figure 72 illustrates the relationships between SBL states.


203

/ 240


WTC

FIT

OPR

EF

SOS

IT

MSD

FU Only

UT

FLT

FOS

Figu Fi gure re 72

Rela Re lati tion onshi ship p Bet Betwe ween en SB SBLL St Stat ates es

8.4 .4.4 .4

Sta St ates Not In Traff ffic ic

NEQ

The following states are all disabled states except for MSD and Under Test Test (UT) which are transitory states due to some automatic function:

204

/ 240

OPR

An SB SBLL in th the e OPR st stat ate e ha hass be been en di disa sabl bled ed by th the e operator.. The SBL cannot perform its functions until the operator operator takes action.

FLT FL T

A fa fata tall er erro rorr ha hass be been en de dete tect cted ed.. Th The e FL FLT T st stat ate e me mean anss the service is unavailable but the SBL has the capability to recover autonomously without operator intervention.

FOS

A fa fata tall er erro rorr ha hass be been en de dete tect cted ed.. Th The e Fa Faul ulty ty Ou Outt of Service (FOS) state means the service is unavailable and the SBL does not have the capability to recover autonomously.. Maintenance action is required. The autonomously operator must use the INIT command to recover the SBL.

NEQ

An SBL in the Not Equ Equipp ipped ed (NE (NEQ) Q) sta state te is not han handle dled d by the system because it has not been configured.



MSD

MSD is a tra transi nsitio tional nal sta state te whi which ch tak takes es eff effect ect wh while ile a board is going through the software and configuration load process. For example, when a fault is detected while the SBL is in the IT state, the SBL state changes to MSD.. It remains in the MSD state while the system MSD determines the effect of the fault and chooses one of the following final states: D D D D

FLT FLT FIT FOS EF.

UT

The SB The SBLL is be bein ing g te test sted ed us usin ing g au auto toma mati ticc pr proc oced edur ures es.. The service is temporarily unavailable. It is possible that due to the test actions, the previous level of service may change. This state is only valid for the Frame Unit Time Slot (FU_TS) SBL when the RTE Loop test is running (G1/G2 BTS only).

SOS

An SBL in the SOS sta state te can cannot not per perfor form m its fun functi ction on because a parent SBL is not operational.

The transitions from one state to another are controlled. The board state of the SBL changes from an active state to another state.

8.4 .4.5 .5

BSS SB SBL L Ope pera rattor Com omm mand ndss The O&M operator commands, described in Table 17, which affect the state of the SBLs are as follows: " " " "


DISABLE INIT RESET RESTART.

205 / 240


Tab able le 17

SBLL O& SB O&M M Op Oper erat ator or Co Comm mman ands ds

Command and Description

Previous State

DISABLE

The board can be in The board is any known or unknown deactivated. state. DISABLE puts the board out of active service for maintenance purposes.

The OMC R is informed over the CMISE link. The SBL is set to the OPR state. The unit is isolated from the rest of the system

The board was previously in a wait state, or performing bootstrap or selftests.

The unit is in an active state (In Traffic (IT)) and all previous active faults related to this SBL are removed from the AIFL. The OMCR is informed over the CMISE link.

Places an active SBL into a disabled state.

INIT Reactivates a component which had been previously disabled. Once initialised, the component is operational and active.

Action Taken

The board passes through all phases: G G G G G G

RESET Acts as a combination of the DISABLE and INIT com mands. It allows the SBL to recover from a situation where the behavior is suspi cious. It initiates selftests and returns the SBL to a known state. This command applies to loadable components (i.e. processor SBLs), or to the BSC, the BTS, the TSC, and the BSS.

Selftests SW download SW start Tests Configuration Operation.

The board was The board passes operational, but usually through all phases: with a malfunction. Selftests SW download SW start Tests Configuration Operation. G G G G

The logical flow described above is initiated. The unit is in an active state (IT) and all previous active faults related to this SBL are removed from the AIFL.

G G

RESTART

The board was The board passes previously operational through these phases: Allows the software to restart (under normal without a download (unlike SW start conditions), in either the RESET), and without losing the FIT or the IT SBL state. Tests context (in most cases). This Configuration helps keep downtime to a Operation. minimum for active systems. This command applies to processor SBLs, BSC, BTS, TSC, and the BSS. G G G G

206 / 240

New State

The logical flow described above is initiated. The unit is in an active state (IT) and all previous active faults related to this SBL are removed from the active AIFL. The OMCR is informed over the CMISE link.



8.4. 8. 4.6 6

Rec ecov over ery y Ex Exam ampl ple: e: CU Fa Fail ilur ures es wi with th BC BCCH CH As an example, this section describes the system system's 's reactions when a CU (or TRE for the BTS A9100) which has the BCCH channel fails. Note

In the BTS A9100, the SBLs FU and CU have been merged into one indivisible indivisible SBL, called called the TRE. At the BSC, however however, all BTS A9100 TRE faults are mapped to the CU to provide compatibility with G1 G1 and G2 BTSs. Thus, at the the BSC all such errors errors are displayed displa yed as CU faults. faults. That is how they they are presented presented in this example. FU faults in G1 and G2 BTSs continue to be reported as such.

Fault Recovery The recovery mechanism in the BSS allows a failed unit to switch to Mechanism a replacement unit, such as: "

Redundant hardware

"

A similar unit which had lower priority active use than the failed unit. (For example, the BCCH has to exist for the cell to function, so another CU/FU pair (TRE in the BTS A9100) is expendable to replace the failed CU).

The recovery mechanism of the BSS recognizes that the CU can change to its twin CU. Note

One CU is used for BCCH channel handling, another is used for normal traffic. If the CU holding the BCCH fails, it is switched out and the second CU takes the place of the first. Below is a step by step scenario of CU recovery.

Scenario


1.

The CU holding the BCCH fails.

2.

The BTS sends the BSC a recovery request, reporting that the CU is faulty and is out of service, and that a recovery is required. requir ed. The BTS also suggest suggestss a new CU to the BSC, BSC, to be used to carry the BCCH. When the recovery request is received, the BSC temporarily blocks the resources while it checks if reconfiguration is available. If reconfiguration is available, the BTS_TEL SBL becomes FIT and all calls on the CU are immediately released. The RSL is blocked and their SBLs are changed to RTS=EF. RTS=EF. All calls on the CU are immediately released.

3.

The BSC sends an alarm to the OMCR, signalling the loss of BCCH.

4.

The BSC attempts a recovery. The recovery command is BTSCONFDATA(2).

207 / 240


5.

The BTS receives and acknowledges the recovery message. It then switches off the faulty CU and switches on the second CU. The second CU adjusts its frequency to the BCCH frequency.

6.

If the configuration was successful, the BTS sends a confirmat conf irmation ion to the BSC. The BSC then sends sends the new SYS_INFO (16).

7.

The BCCH is now broadcasting on the same frequency as before, via the newly configured CU.

8.

The BTS sets its BTS_TEL SBL to FIT and informs the OMCR by sending an end of alarm. The BTS_TEL remains FIT due to the loss of a channel.

9.

If the new CU was previously IT, then all resources are lost. An alarm start is sent towards the OMCR for each channel lost.

Figure 73 shows the redundancy process for a failed CU with BCCH.

208

/ 240



OM C

BSC

BTS CU Fault

1

BTS_TEL=IT Resources blocked, BCCH reconfiguration possible 3

2

BTS_TEL=FIT

4 5 BTS performs the reconfiguration

BTS_TEL=FIT

6 8

9

BTS_TEL=FIT

Figur Fi gure e 73 Note

8.4 .4.7 .7

Exampl Exa mple: e: Lo Loss ss of CU Hol Holdin ding g BCC BCCH. H.

BTS_TEL SBL describes the status of the GSM defined BTS telecom functions. Its state is driven by operator commands, or by correlation of the LAPD RSL states or of the different CUs.

Res ese et Exa xam mpl ple: e: TSC RE RESE SET T As an example, this section describes the system's system's reactions when the TSC is reset by the operator:

Example TSC Reset


1.

The operator invokes the RESET command. The OMCR accepts the command and places the TSC in the MSD state. The TSC remains in the MSD state while transmitting the reset to the BSC.

2.

The BSC passes the RESET command to the TSC. It receives the ACK acknowledgement message from the TSC, disables dis ables the TSC LAPD Signalling Link (TSL) to the BSC, and starts the persistency timer.

3.

The TSC accepts the command and places itself in the MSD state. The TSC disables the TSL from its end, and performs a selftest. After ten seconds the TSL becomes active again.

4.

The persistency timer starts the BSC, and sends a state change message to the OMCR.

209 / 240


5.

The TSL is reestablished and the TSC resets and reconstructs its alarm list. Once this is done the TSC sets its status to IT and sends the BSC a reset report.

6.

The reset report is acknowledged. It is converted to a CMISE message which is sent to the OMCR. The OMCR resets its view of the TSC to the IT state, and clears alarm lists for all SBLs for that TSC.

7.

The TSC then sends a fault indication message to the BSC. The BSC acknowledges the message. The BSC packages the information as a alarm report in CMISE and sends the information to the OMCR.

8.

The OMCR requests a state audit and an AlarmsInForce audit. These are performed at the same time so the OMCR and TSC are synchronized.

9.

The TSC is now in operation and therefore in the ACTIVE state.

Figure 74 shows the TSC Reset process. OMC

BS C

TSC

TR_O&M=IT

1

TSC=IT

2

TSC=MSD

3

TSL DOWN SELFTEST TSL UP reconstructs BSC detects TSL alarm list TR_O&M=IT

TSC=MSD

TSC=IT

audit

TSC=IT 7

Fig igu ure 74

210

/ 240

TSC TS C Rese sett



8.5

Tracing Within the BSC there are two types of tracing: "

Call tracing which can be initiated from a GSM phase 1 MSC, the OMCR or the BSC Terminal.

"

IMSI traces (based on mobile identity) which can be initiated from a GSM phase 2 MSC.

The trace data collected in the BSC is formatted into files and transferred, using FTAM, to the OMCR or to the BSC Terminal (if the trace was initiated there). The file formats, and contents, for call and IMSI traces are different. The BSC performs error checking on the message initiating the trace procedure and verifies that trace data can be collected and stored in the BSC. Separate trace record structures are created in the BSC to differentiate between call and IMSI trace records.

8.5.1

Call Tracing Call tracing allows the operator to trace call events on a particular channel and timeslot on a BTS. These trace jobs are initiated from the OMCR. The NMC initiates call tracing jobs on specified transactions (subscriber call, location update, short message, etc). In this way, an operator can trace and analyze call anomalies in a particular cell when: " " "

Intermittent fault alarms appear There is low frequency of successful handovers Customers Custo mers complain about a parti particular cular cell.

The current implementation implementation of call tracing provides mainly performance measurement and handover event information. The following menus are available to the operator: " " "

Performance Management BSC Call Management Management Trace Job Management.

When a trace exceeds 20K bytes, a new trace file is created and the previous file is subsequently transferred to the OMCR (using FTAM). The trace is a continuous process and many 20k files are transferred to the OMCR. The BSC is limited to 99 concatenation files. These files are shared between trace jobs and measurement jobs, so care must be taken not to exceed this limit. This can be achieved by limiting the traces and measurements jobs running on the same BSC.


211 / 240


On completion of the file transfer, the OMCR informs the BSC that the file has been read. The operator can then archive and analyze the trace file offline. (If more than one trace is produced for a job, the files are concatenated in the archived file). Trace jobs can also be created from the local BSC Terminal. The trace files that result from these jobs are not transferred to the OMCR. When the trace data is ready for collection, the BSC notifies the local terminal. The trace data is then retrieved from the BSC, by the operator, using a copy file command. For further information inform ation refer to the BSC Terminal User Guide document.

8.5.2

IMSI Tracing IMSI tracing allows the operator to obtain call path information on a specific MS's connection, based on the mobile identity. This information is gathered from different network elements, together with traffic data and other events related to the call, independent of performance measurement functions. The mobile identity used may be the IMSI, IMEI or neither, depending on the trace invocation received from the MSC. The MSC controls the trace activation towards the BSC by using the MSC_INVOKE_TRACE MSC_INVOKE_TRA CE message. The trace is not restricted to speech but includes any information which requires the setup of a connection to the MS. This information can include location updating, short messages and supplementary service operations. Trace record information can be used in the analysis of: "

Cell footprinting

"

Network integrity

"

Network Netwo rk Qualit Qualityy Of Servi Service ce

"

Equipment used for mobile origin Equipment originated ated or termi terminated nated call connections

"

Destination, forwarded to, and translated numbers used on call connections.

IMSI trace files include additional data supplied in the message from the MSC. This information is transparent to the BSC and is used by network management personnel to correlate trace data from different BSCs and MSCs. IMSI trace files are always collected by the OMCR and then passed to the MSC that initiated the trace.

212 / 240



8.6

Measurement Jobs OMCR measurement jobs are defined by the operator to acquire raw or formulated counter/measurement information. The information received is then used to analyze the state of the system in operation. There are several types of performance management types or jobs. They are all based on counter collection and analysis (warning, snapshots and measurements). The only real differences are: " "

The treatment and analy analysis sis of the collected information information Whether collection is one shot, timed periods, or permanent.

This section describes:

8.6. 8. 6.1 1

"

The reformatting reformatting and analysis of all performance performance inform information ation in the OMCR

"

The data collection process in the BSC and the OMCR.

OMC OM CR R Me Meas asur urem emen entt Jo Job b Cl Clas asse sess There are four main Measurement Job class groups described in Table 18.

Tab able le 18

Meas Me asur urem emen entt Jo Job b Cl Clas asse ses s

Class Group

Description

Raw Ra w Me Meas asur urem ement entss

This cla This class ss pr prov ovid ides es pe perm rmane anent nt or sc sche hedu dule led d jo jobs bs ba base sed d on one ra raw w me meas asur ure e ment type.

Mediated Media ted Measu Measurement rementss

This class provid provides es permane permanent nt or or schedul scheduled ed jobs jobs based on Mediat Mediated ed counte counters. rs.

Mediat Med iated ed Warn arnings ings

This clas This classs pro provid vides es alar alarms ms whe when n a Med Mediat iated ed cou counte nterr, or a gro group up of Med Mediat iated ed counters, pass a threshold (or thresholds) defined when the task was invoked. Typical use is to provide a traffic overload warning as an avoidance measure.

Snap Sn apsh shot ot Jo Jobs bs

This cl This clas asss pr prov ovid ides es a gr grap aphi hica call re resu sult lt of a co coun unte terr of a pa part rtic icul ular ar BS BSS S. For example, the total erlangs per channel can be displayed. (Erlangs is a statisti cal value to show the theoretical number of users the channel can provide).


213 / 240


8.6 .6.2 .2

Meas Me asu urem emen entt Res esu ult lts s Measurement results can consist of the following: "

Raw measurements Raw measurement information is collected on every functional unit of the BSC.

"

Mediated Device Counters Mediated Device Counters are derived from raw measurements. They supply the operator with more precise information. For example, to obtain the percentage of handover failures, the number of raw measurements (the number of different failures and the number of total attempts) is collected. The information is collated and a failure rate is calculated as a percentage.

8.6.3

Counters The relationship between counter objects is shown in Figure 75. The types of object that make up the hierarchical counter tree are as follows: " " " " " "

Mediated Device Objects Mediated Device Counters Virtual Raw Measurements Raw Measurement OMCR (job) Raw Measurement BSC (job) Measurement Administrator

measurement request, all the Mediated Device When an operator performs a measurement Objects details of the request are stored in the Mediated Device Object. The request requires one or more counters.

Mediated Device Counters

214

/ 240

Mediated Device Counters are created per Mediated counter in the definition of the Mediated Device Objects. Mediated Device Counters handle the calculation of a counter value which is based on a series of raw measurements counters. The Mediated Device Counter requires results from several raw measurements to perform its calculations. That is, to obtain the percentage of handovers requires the number of successful handovers, divided by the number of handover attempts. This information is provided by the Virtual Raw Measurements, one per raw_counter type.



Virtual Raw Measurements

The Virtual Raw Measurements collect and process data from raw counters count ers and manage the report reporting ing interval. The Virtu Virtual al Raw Measurement is a virtual image of the raw measurement. The information however, is dedicated for use by its Mediated counter (i.e. report intervals).

Raw Measurement OMCR

The raw measurement handler is the part of the OMCR which is in contact with the BSC. It receives counter information. It is also responsible for asking the BSC to start rawmeasurement jobs on its behalf.

Raw Measurement BSC

The raw measurements are invoked on the BSC at a rate of one per measurement type. These tasks obtain the data, which is available on the Central Data Collector. The data is passed on to the OMCR, via CMISE/FTAM, CMISE/FTAM, every five minutes.

Measurement Administrator

The Measurement Administrator interrogates the Central Data Collector on behalf of the active raw measurement jobs. It passes the information on to the OMCR.


215

/ 240


mediated device object

raw measure

mediated measure

mediated device counter

mdc(j)

mediated warning

snapshot

m dc ( l )

mdc(m)

mdc(k)

virtual raw measurement

T1i

raw measurement handler

Rm (T1)

Rm (T2)

Rm (T3)

Rm (T6)

Rm (T1)

Rm (T2)

Rm (T3)

Rm (T6)

T1j

T2j

T1k

T3k

T6l

T6m

T1m

OMCR BSC

Measurement Administrator

Figu Fi gure re 75

Coun Co unter ter Ob Obje ject ct Tre ree e

8.6 .6.4 .4

Datta Coll Da lle ect ctio ion n on th the e BS BSC C

Central Data Collector

Measurement information is collected from parts of the BSC. Each module has a Local Data Collector, which collects the data for its particular module. For example, in the TCU the Local Data Collector collects data for the Abis link and for the corresponding BTS. This information is passed on towards the Central Data Collector, where the information is collected for later or immediate use. There are three types of information passed to the Central Data Collector Collec tor from the Local Data Collectors: Collectors: "

Cumulated Counters The Central Data Collector polls the Local Data Collectors once every fiveminutes to collect the data. The counter types range from 1, 3to 9 and 26 to 28. Counter types are defined in the Operations & Maintenance Reference Guide. Guide.

216

/ 240



"

Observation Measurements Observation measurements are immediately sent from the Local Data Collector to the Measurement Administrator, Administrator, bypassing the Central Data Collector. Collector. The counter types range from 10 to 15.

"

Status Inspection Status inspection is provided on demand from the Central Data Collector, Collector, on the number of open radio channels. The Central Data Collector polls the Local Data Collectors every 20 seconds. The counter type is 2.

If a particular control board becomes inoperable, the Local Data Collector running within this control board is unavailable. This occurs when the subsystem remains inoperable. The Measurement Administrator is responsible for scheduling jobs, and for providing results to the OMCR. The Measurement Administrator treats the demands of active raw measurement jobs by accessing the Central Data Collector for the information, and then passing the information on to the OMCR. This check is done every five minutes. Figure 76 shows the data collectors in the BSC. BTS

BSC

TCU

SYS CPRA

TSS

DTC

FU

TC

Local Data Collector



OSI CPRA

TCU

Central Data Collector

FU


Figu Fi gure re 76

Measurement Local Data Administrator Collector

Data Da ta Co Coll llec ector torss wi with thin in th the e BS BSC C


217

/ 240


8.6.5

Counter Examples The following examples show how the mediated device counters are mapped down to basic raw measurements types. Two measurement operations are performed for requested type 1 and type 5 raw measurements. Figure 77 shows an example of the counter object tree required for each job. Job1

Job1 requests the average TCH hold time per BTS (PR27), and the number of successful seizures (PR18) results from two Mediated Device Counters. Counter PR27 = C38/(C17+C18). Counter Count er PR18 = C1+C2 C1+C2+C10. +C10.

Job2

Job2 requests a Mediated Warning of the number of SDCCH radio losses (RD28) (RD28).. Counter RD28 = C6+C7. All the above counters are type 1 counters, except C38 which belongs to type 5.

Note

218 / 240

Refer to the Operation & Maintenance Reference Guide for more information about counter types and definitions.



mediated meas

mediated device object

mediated device counter

PR27

virtual raw measurement

T1

raw measurement handler

T5

Rm (T1)

Rm (T5)

Rm (T1)

Rm (T5)

JOB1

mediated JOB2 warning

PR18

RD28

T1

T1

OMCR BSC

Figure Fig ure 77

Exampl Exa mple: e: Cou Counter nter Obj Object ect Tree


219

/ 240


8.7

Audits Audits can be automatic or invoked by an operator. operator. They can be performed at several levels: " "

Audit Types Tab able le 19

From the OMCR to the TSC or the BSC From the BSC to the BTS.

There are several types of audits, as described in Table Table 19.

Aud Au dit Typ ypes es

Type

Description

Cloc Cl ockk Au Audi ditt

Cloc Cl ockk au audi dits ts syn ynch chro roni nizze th the e cl cloc ocks ks to the ma mast ste er da datte an and d ti time me..

Log ogic ical al Au Audi ditt

A lo logi gica call au audi ditt is pe perf rfor orme med d on lo logi gica call pa para rame mete ters rs.. Th The e lo logi gica call pa para rame mete ters rs include dynamic cell information, its power ratings, information on adjacent cells, the radio configuration of the cell, and hopping and paging groups.

Software Softwa re Ve Version rsion Audit

The softwa software re versio version n audit contr controls ols the versio versions ns of softwa software re that exist on the subsystem.

Hard Ha rdwar ware e Aud Audit it

Hardwa Hard ware re au audit ditss co cont ntro roll th the e ha hard rdwar ware e on th the e su subs bsys yste tem. m. Th This is aud audit it pr provi ovide dess a physical list of all components in the subsystem, their SBLs, and their associated RITs. RITs. The OMCR updates up dates the database with this information.

Alarm Audit

The OMCR requests the AIFL from a unit of the BSS. The OMCR then then compares this with its own list and updates its database if there are any differ ences.

Stat St ate e Au Audi ditt

A st stat ate e au audi ditt ch chec ecks ks th the e st stat ate e of SB SBLs Ls on a pa part rtic icul ular ar su subs bsys yste tem, m, to en ensu sure re th that at SBL databases are synchronized. All the SBLs and their states are compared with the data in the OMCR. If the SBL does not exist in the database, it is created and its state is registered.

A suite of audits is automatically invoked by the OMCR OMCR or the BSC, to resynchronize the system. This is done: "

To perform a RESET/RESTART.

"

When there is a loss of links between subsystems. This ensures that the system databases are synchronized after autonomous operation while the link was down (i.e. the BTS_O&M was disabled).

"

To make changes in the databases, without the possibility of aligning both subsystems.

"

To start a BSC AlarmsinForce audit if the BSC alarm queue overflows.

"

To perform software database replacement.

Audit information for the whole whole system is stored in the OMCR and is stored in the Management Information Base (MIB).

220 / 240



Audit Flow

Audit flow is based on an action request from the OMCR, or on an automatic request. The subsystem receiving the audit request performs an audit of its functional units. The reply can have one or several report messages to pass the information back to the request originator. The request originator can generate more actions based on the information received. For example, when the state of the CU and its pair FU do not match, the BSC or OMCR disables the FU/CU pairs. The OMCR, on reception of the audit report, updates its database. During download the results of the software audit are used to provide the list of modules the OMCR needs to update the BSS subsystem. This is done by comparing the OMCR lists of modules to transfer, and their version numbers, to see if they already exist in the subsystem. Only the newer versions are transferred to the subsystem.


221

/ 240


8.8 8. 8

Modi Mo dify fyin ing g Tel elec ecom om Par aram amet eter erss Modification of telecom parameters occurs: "

On the BSC The BSC database is updated with the modifications.

"

On the BTS The BSC informs all of the BTSs affected by the changes, using the following commands to change the telecom parameters: D D

222 / 240

BCCH_INFO(SYS_INFO 14) to BCCH FU SCCH_FILL(SYS_INFO 5,6) to all FUs.


Abbreviations

Abbreviations Abbreviation s ACCH

Associated Control Channel

ACELP

Algebraic Code Excited Linear Prediction

AGCH

Access Grant Channel

AIFL

AlarmsInForce List

AN

Antenna Network

AuC

Authentication Center

BC B

Base Station Control Bus

BC C H

Broadcast Control Channel

BER

Bit Error Rate

BIE

Base Station Interface Equipment

BS

Base Station

BSII

Base Station Internal Interface

BSS

Base Station Subsystem

BSSAP

BSS Application Part

BSSMAP

BSS Management Application Part

CACO

Call Control

C BC H

Cell Broadcast Channel

CCCH

Common Control Channel

CCH

Control Channel

CDM

Configuration Data Message

CI

Cell Identity

CIC

Circuit Identification Code

CM

Call Management

CMISE

Common Management Information Service Element

CPF

Configuration Parameter Data File

CPR

Common Processor

CPRA

Common Processor Type A

CU

Carrier Unit

DCCH

Dedicated Control Channel

DRX

Discontinuous Reception (mechanism)

DTAP

Direct Transfer Application Part


223

/ 240

Abbreviations

DTC

Digital Trunk Controller

DTE

Data Terminal Equipment

DTX

Discontinuous Transmission (mechanism)

DTX DT X/V /VAD AD

Disc Di scon onttin inuo uous us Tra ran nsm smis issi sio on/ n/V Voic ice e Ac Acti tivi vitty De Dettec ecttio ion n

EACB

External Alarm Collection Board

EF

External Fault

EFR

Enhanced FullRate

EIR

Equipment Identity Register

ETSI

European Telecommunication Standards Institute

FACCH

Fast Associated Control Channel

FCCH

Frequency Correction Channel

FDMA

FrequencyDivision Multiplex Access

FH

Frequency Hopping

FHS

Frequency Hopping System

FHU

Frequency Hopping Unit

FIT

Faulty In Traffic

FLT

Faulty

FOS

Faulty Out of Service

FTAM

File Transfer Access and Management

FU

Frame Unit

FU_TS

Frame Unit Time Slot

GSM

Global System for Mobile Communications

HLR

Home Location Register

HMI

Human Machine Interface

HSN

Hopping Sequence Number

ID

Identification

IE

Information Element

IMEI

International Mobile Station Equipment Identity

IMSI

International Mobile Subscriber Identity

ISDN

Integrated Services Digital Network

ISO

International Standards Organization

IT

In Traffic

ITU

International Telecommunications Union

224

/ 240


Abbreviations

Kc

Ciphering Key

Ki

Individual Subscriber Authentication Key

L2ML

Layer 2 Management Link

LA

Location Area

LAC

Location Area Code

LAI

Location Area Identity

LAPD

Link Access Procedure on the D Channel

LAPDm

Link Access Protocol on the Dm Channel

MA

Mobile Allocation

MAIO

Mobile Allocation Index Offset

MCC

Mobile Country Code

MCLU

Master Clock Unit

MIB

Management Information Base

MIE

Mandatory Information Element

MIT

Management Information Tree

MM

Mobility Management

MNC

Mobile Network Code

MS

Mobile Station

ms

milliseconds

MSD

Maintenance Seized (due to an operator action)

MTP

Message Transfer Part

NEQ

Not Equipped

NMC

Network Management Center

NSS

Network Subsystem

NTC

Night Time Concentration

O&M

Operations and Maintenance

OMC R

Operations and Maintenance CenterRadio

OML

Operations and Maintenance Link

OMU

Operations and Maintenance Unit

OPR

Operator Out of Service

PBGT

Power Budget

PCH

Paging Channel

PCM

Pulse Code Modulation


225

/ 240

Abbreviations

PLMN

Public Land Mobile Network

PM

Performance Management

PSTN

Public Switched Telephone Network

RACH

Random Access Channel

RAND

Random Number (used for authentication)

REF

Random Access Information Value

RF

Radio Frequency

RIT

Replaceable Item

RLP

Radio Link Protocol

RPC

Radio Power Control

RR

Radio Resource

RRM

Radio Resource Management

RSL

Radio signaling Link

RTELTP

Radio Test EquipmentLong Term Prediction

RTS

Radio Time Slot

RXLEV

Received Signal Level

RXQUAL

Received Signal Quality

SABM

Set Asynchronous Balanced Mode

SABME

Set Asynchronous Balanced Mode Extended

SACCH

Slow Associated Control Channel

SBL

Security Block

SCCP

signaling Connection Control Part

SCH

Synchronization Channel

SCP

Signalling Control Processor

SDCCH

Standalone Dedicated Control Channel

SID

Silence Indication

SIM

Subscriber Identity Module

SM

Submultiplexer

SMS

Short Message Service

SMS CB

Short Message Service Cell Broadcast

SOS

Software Out of Service

SS

Supplementary Service

SS7

signaling System No. 7

226

/ 240


Abbreviations

SUM

Station Unit Module

S CPRA

System Common Processor Type A

TC

Transcoder

TCH

Traffic Channel

TCH/F2.4

A Full Rate Data TCH (<2.4 Kbit/s)

TCH/F4.8

FullRate Data Traffi ficc Channel (4.8 Kbit/s)

TCH/F9.6

FullRate Data Traffi ficc Channel (9.6 Kbit/s)

TCH/FS

A Full Rate Speech TCH

TCH/H2.4

A Half Rate Data TCH (<2.4 Kbit/s)

TCH/H4.8

A Half Rate Data TCH (4.8 Kbit/s)

TCH/HS

A Half Rate Speech TCH

TCU

Terminal Control Unit

TDM

Time Division Multiplex

TDMA

Time Division Multiple Access

TEI

Terminal Endpoint Identifier

TMN

Telecommunications Management Network

TMSI

Temporary Mobile Subscriber Identity

TOA

Time Of Arrival

TRAU

Transcoder Rate Adapter

TRE

Transceiver Equipment

TS0

Time Slot 0

TSC

Transcoder Submultiplexer Controller

TSL

TSC LAPD Signalling Link to the BSC

TSS

Transmission Subsystem

UT

Under Test

VAD

Voice Vo ice Activity Detection

VLR

Visitor Location Register

WTC

Wait Traffic Traffic Clear


227

/ 240

Abbreviations

228 / 240


Appendix A Air Interface Channels

Appendix A A.1

Traffic Channels TCH

A.2

Air Interface Channels

Traffic Channel FullRate: used on the uplink and downlink to transmit user traffic. The TCH uses 24 out of 26 sequential slots on its channel to transmit speech or data.

Broadcast Channels FCCH

SCH

BCCH

Frequency Correction Channel: used on the downlink (on the BCCH timeslot) for frequency correction of the MS with the BTS. Synchronization Channel: used on the downlink (on the BCCH timeslot) for frame synchronisation of the MS with the BTS. Broadcast Control Channel: used to broadcast system information to the MSs on the downlink, to give the cell configuration and how to access the cell. " " " " " " " "

A.3

Number of CCCHs Whether CCCHs are combined with SDCCHs ACGH allocation Paging Organization CGI, LAI Cell Allocation BCCH frequencies frequencies of neigh neighbor bor cells Maximum transmit power, which is allowed in the cell.

Common Control Channels CCCH

Common Control Channel: for contr control ol inform information ation before a dedicated channel is assigned. It comprises the RACH, AGCH and PCH.

RACH

Random Access Channel: used on the uplink (on the CCCH timeslot) by the MS for initial access to the network.

AGCH

PCH


Access Grant Channel: used on the downlink (on the CCCH timeslot) gives to the MS access information before a dedicated channel is assigned. Paging Channel: used on the downlink (on the CCCH timeslot) for paging messages to the MS.

229 / 240

Appendix A Air Interface Channels

A.4

Dedicated Channels SDCCH

CBCH

A.5

Signalling Dedicated Signalling Dedicated Chann Channel: el: used for signalling and short message information. Cell Broadcast Channel: uses an SDCCH channel but all MSs will then know it is for Short Message Service  Cell Broadcasts.

Associated Channels SACCH

Slow Associated Control Channel: associated with a TCH, which uses 1 out of 26 slots for signalling purposes.

FACCH

Fast Access Control Channel: associated with a TCH, and can steal slots out of 24 of 26 slots which are normally dedicated to the TCH for signalling purposes as well as the SACCH slot.

Traffic =

Broadcast =

Common =

TCH

SACCH

FACCH

FCCH

SCH

BCCH

RACH

AGCH

PCH

KEY Dedicated =

SDCCH

Uplink Downlink

Figur Fi gure e 78

230

/ 240

Channe Cha nnels ls and The Their ir Dir Direct ection ion of Flo Flow w


Index

Index A

B

A interface, 41

Base Station Control Bus, 188, 199

Alaw,, speech encoding, 167 Alaw

Base Station Controller. See BSC

Abis interface, 42

Base Station Interface Equipment, 29

Abis Signalling Links Static Multiplexing, 25, 159

Base Station Internal Interface, 188, 199

Access to PM Raw Counters via Binary Files, 26, 162

Base Station Subsystem. See BSS

Air interface, 43

Base Tranceiver Station. See BTS

Alarms, 194 audit, 220 BSC, 195 BTS, 199 filtering, 195 generation, 194 inforce, 195 mediated warning, 213 queue BTS, 200 status, 190 TSC, 200

Board, operation, 201

Alcatel, EVOLIUM Radio Solutions, 18 Alcatel BSS Features, 23, 146 Alerter,, BSC, 24, 156 Alerter Algorithms encryption, 72 handover,, 99 handover hopping, 137 Antenna diversity, 23, 147 preamplifier,, 23 preamplifier

Bootstrap, 201 BSB, 188, 199 BSC alarms, 195 alerter, 24, 156 call release, 122 data collection, 216 description, 28 O&M role, 184 OMCR/BSC command flows, 191 overload detection, 108 BSII, 188, 199 BSS description, 27 features, description, 129 features, overview, 21, 130 functions, 19 O&M functions, 184 SBL Operator Commands, 205, 206

Automatic Paging Repetition, 26, 161

BTS alarm queue, 200 alarms, 199 auto identification, identification, 26, 160 automatic powerdown, 26, 160 call release, 124 description, 28 O&M role, 186188 overload detection, 107 power control, 132 power level, 135 queue, 69 sectored site, 175 TC alarms, 127

Automatic PowerDown, BTS, 26, 160

BTS A9100, TRE SBL, 207

Asynchronous, handover, 100 Ater interface, 42 Audits, 220 Authentication, 77 centre, 32 identities, 77 Ki value, 77 procedure, 78 random number, 77 Auto Identification, BTS, 26, 160


231

/ 240

Index

BTS_TEL, 196, 207, 208

C Call See also call handling, release, set up connecting, 60 control, 39 mobile originated, originated, 50 mobile terminated, 61 mobility management, management, 48 quality, 89 reestablishment by MS, 22, 143 release, 111 service, 48 setup, 19 tracing, 211 types, 48 user traffic, 48 Call handling, 20 error handling, 88 Call release, 20, 111128 channel change, 119 procedures procedu res in normal service, service, 114 resources, 112 SCCP SCC P, 115 special cases, 120 BSC initiated, 122 BSC initiated SCCP release, 123 BTS initiated, 124 BTS initiated LAPD failure, 124 MS initiated, 126 MS initiated radio link failure, 126 reset, 120 reset circuit, 120 Call set up, 19 authentication, 49, 55 channel activation, 52 ciphering, cipheri ng, 49, 55 immediate assignment, 53 normal assignment, assignment, 49 phases,, 49 phases radio and link establishment, 49 Calls mobility management, management, 19 supplementary service, 19 user traffic, 19

Cell concentric, 174 environments, 23, 146, 171 extended, 176 hierarchical network, 178 list identifier, 66 list information element, 66 macrocell, 178, 179 microcell, 179 mini cell, 178 sectored site, 175 target evaluation, 99 target list, 91 type, 172 types, 23, 146 umbrella, 178 Cellularr Environ Cellula Environment, ment, 21, 131 Channels activation, activat ion, 52, 58 allocation, allocat ion, traff traffic, ic, 57 control, 44 interference levels, 91 traffic, 44 Ciphering, 79 BSS capability, 80 encryption algorithms, 79 handover, 82 keys, 80 Mobile Station capability, 79 mode, 81 procedure, 81 Classmark handling,, 72 handling information element, 72 procedure, 55 updating, 74 Clipping, 139 Clock audit, 220 Communication, mechanism, 191 Concentric cell, 174 zones, 174 Configuration download, 201 SW management, 190 Congestion, 69 Contention resolution, 53 Control Contr ol channel channel,, 44

232

/ 240


Index

Correlation, 194 Counters, 213, 214 cummulative, 216 mediated device, 214

DTX, discontinuous transmission, 22, 138

E EFR. See Enhanced Full-Rate

D Daisychain, map, 195 Data central collector, 216 collection, BSC, 216 handling, 168 interleaving, 169 nontransparent, 170 rate adaptation, 169 transparent, 169 V.110 V .110 protocol, 168 Data link layer A interface, 41 Abis interface, 42 Air interface, 43 Device counters, mediated, 214 Directed retry, 70 handover,, 90 handover Disable, 202 Discontinuous reception, 142 Discontinuous transmission, 138 downlink, 139 flag, 139 uplink, 140

Encryption A5/1, 7274 A5/2, 73 algorithm, 7274 Enhanced FullRate, 23, 44, 144 Equipment Identity Register, 32 Erlangs, 213 Error,, persistancy Error persistancy,, 195 Event, changes, 193 EVOLIUM Radio Solutions, 18 Extended cell, 176 overlap overla p zone, 176 External components, 31 handover, 89, 100 handover procedure, 104

F Fading, 136, 147

Distance, handover, 96

Failure DTC, 195 link, 196 software, 197 TCU, 195

Download configuration, 201 software, 201

Fault begin / end, 194 correlation, 194

DRX, discontinuous reception, 22, 142

Fax data rate change, 87 nontransparent, 87 transparent, 87

DTC, 197 failure, 195 overload action, 108


233

/ 240

Index

Features Abis signalling links static multiplexing, 25, 159 access to PM raw counters via binary files, 26, 162 antenna diversity, 23 antenna preamplifier equipment, 23 auto identification, 26 automatic paging repetition, 26, 161 automatic power down, 26 BSC Alerter, 24 BSS, 21, 129, 130 call reestablishment reestablishment by the MS, 22 cellular environment, 21, 131 discontinuous reception, 22 discontinuous transmission/voice activity detection, 22 enhanced fullrate, 23 frequency hopping, 22 improved multipath delay equalization, 24 minimum frequency spacing, 24 multiple human machine interface, 24 night time concentration, 24 OMCNSS session from OMCR terminal, 25 OMCR connection to TSC trough BSC, 25, 158 power control due to radio link failure, 25, 158 Q3 multimanager, 25, 158 rpc uplink and downlink, 22 short message service - cell broadcast, 22 transcoder pools, 26, 159 typess of cell enviro type environments nments,, 23, 146 usage state on demand, 24 X.25 redundancy redundancy,, 24 Features Defined in the GSM Recommendations, 21, 131 Features, Service Improvement in Alcatel BSS, 23, 146 new, 25, 158 Filtering, alarms, 195 Flag, DTX, 139 Frequency carrier spacing, 24 diversity,, 136 diversity hopping, 22, 135 MAIO, 136

Functions BSC O&M, 184 BSS, 19 BSS O&M, 184 BTS O&M, 186188 call setup, 19 operations & maintenance, 21 telecommunications, 39 TSC O&M, 188

G GSM features defined in, 21, 131 system functions, 19

H Handover, 89 alarm, 91 algorithm, 99 asynchronous, 100 better cell, 95 better zone, 94 ciphering, 82 directed retry, 70, 90 external, 90 internal, 90 distance, 96 external, 89, 100 interBSS, 100 intercell, 100 internal, intern al, 89, 100 intracell, 100 level intercell, intercell, 93 margin, 99 micro to macrocell, 179 microcell, 92, 179 mobile velocity dependent, 97 power budget, 95 preparation, 91 quality and level, 92 quality intercell, 94 quality intracell, 94 queueing, 69 synchronous, 100 Hardware audit, 220 Hierarchical network, cells, 178 Home Location Register, 32

234

/ 240


Index

Hopping frequency,, 135 frequency sequence number, 136 Human Machine Interface, 24, 149 site configuration, 150

I Immediate assignment, 53 SCCP connection, 54 IMSI AttachDetach, 49, 64 IMSI tracing, 212 Incall modification, 85 procedure, 86 types, 85 Information element, mandatory, 116 Init, 202 InterBSS, handover, 100 Intercell, handover, 100 Interface A, 41 Abis, 42 Air,, 43 Air Ater,, 42 Ater Q3, 38 Multimanager, 25, 38, 158 Interference, 130 Internal handover, 89, 100 handover procedure, 101 Intracell, handover, 100

J Jobs, snapshot, 213

L LAPD, failure, 124 LAPDm, disconnect, 127 Layers Call Management, 39 data link A, 41 data link Abis, 42 data link Air, 43 Mobility Management, 40 physical A, 41 physical Abis, 42 physical Air, 43 Radio Resource Management, 40 Level intercell, handover, 93 Location Area Identity, 34 Location updating, 34 Logical audit, 220

M Macrocell, 178, 179 Management, network, 37 Margin, handover, 99 Measurements administrator,, 214 administrator BSC, 214 BTS power, 132 counters, 214 job classes, 213 mediated, 213 OMCR, 214 radio, 90 radio link, 132 raw, 213 results, 214 virtual raw, 214 Mediated Device Counters, 214


235

/ 240

Index

Mediated Device Objects, 214

physical context confirm, 58 physical context request, 58 power command, 135 queueing indication, 70 release indication, 117 reset, 120 reset circuit, 120 RF channel release, 118 RF resource indication, 57 SCCP connection confirm, 54 SCCP connection request, 54 SCCP release complete, 116 SCCP released, 116 service request, 54 set up, 62 setup, 55 system information, 46

Mediation, 214 Messages alerting, 60, 63 assign failure, 57 assignment command, 59 assignment complete, 59 assignment failure, 57, 69 assignment request, 57 authentication reject, 78 authentication response, 78 block, 120 BTS power control, 135 call confir confirmation mation,, 62 call proceeding, 55 channel activation, activation, 52, 58 channel release, 117 channel request, 50 channel required, 52 cipher mode, 81 cipher mode complete, 81 cipher mode reject, 81 classmark change, 74 classmark enquiry, 74 classmark request, 74 classmark update, 74 clear command, 116 clear complete, 116 connect, 60 connection, 63 deactivate SACCH, 117 disconnection, 115 encryption command, 81 establish indication, 54, 59 handover command, 102 handover complete, 102 handover detect, 105 handover detection, 102 handover performed, 102 immediate assign, 53 IMSIattachdetach, 49 measurement report, 90, 132 measurement result, 90, 132 mode modify, 86 modify,, 86 modify paging, 61, 66 paging command, 61, 66 paging request, 61 paging request type x, 67 paging response, 61, 66 permitted algorithm, 81

236

/ 240

Microcell, 179 handover, 179 thresholds, 179 Mini cell, 178 Mobile, velocity dependent handover, 97 Mobile allocation, 136 Mobile Allocation Index Offset, 136 Mobile originated call, 50 Mobile services Switching Center. See MSC Mobile Station. Station. See MS Mobile terminated call, 61 Mobility Management, 40 Mobility management calls, 19 MS allocation, 136 call reestablishment, 22, 143 call release, 126 cell selection, 33 ciphering capability, 73 class barring, 109 classmark, 72 description, 32 idle mode, 33 location updating, 34 phase 2 support, 142 power control, 132 power drain, 130 revision level, 73 RF power level, 73


Index

MSBS, absolute distance, 133

OMCR Connection to TSC Through BSC, 25, 158

MSC, description, 32

Operations & Maintenance, 21

Multiframe, 43

Operations and maintenance, 183

Multipath Delay Equalization, 24

Operations and Maintenance CenterRadio. See OMCR

N Network, management, 37 Network Management Center. See NMC Network Subsystem, 31 New Service Improvement Features, 25, 158 Night Time Concentration, 24, 151 NMC, 27, 37 Nontransparent data, 170 Fax Group 3, 87 Normal assignment mobile mobil e origin originated ated call, 55 mobile terminated call, 62

Overload BSC detection, 108 BTS detection, 107 control, 107 DTC action, 108 MS class barri barring, ng, 109 TCU action, 108

P Paging, 65 cell list identifier, 66 messages, 61 procedure, 61 request types, 67 Parameters, modification, 222 PBGT, handover, 95

O O&M BSC role, 184 BTS role A9100, 187 G1 & G2, 186 command flow, 191 communication mechanism, 191 counters, 213 data collection, 216 observation measurements, 216 OMCR role, 190 TSC role, 188 OMCR description, 36 HMI access, 149 measurement job classes, 213 O&M role, 190 OMCNSS Session from OMCR Terminal, 25


Persistancy, 195 Phase 2, MS support, 142 Physical layer A interface, 41 Abis interface, 42 Air interface, 43 Power budget, handover, 95 Power control BTS, 132 decision, 133 handover,, 133 handover MS, 132 radio, 131 reasons, 131 RXLEV, 134 RXQUAL, 134 Power Control due to Radio Link Failure, 25, 158 Power level, BTS, 135

237

/ 240

Index

Procedure, classmark, 55

Reporting, periods, 133

Procedures authentication, 78 call release, 111 channel activation, 52 ciphering, 81 classmark, 75 external handover, 104 frequency hopping, 136 immediate assignment, 53 incall modification, modification, 86 internal handover, 101 normal assignment, assignment, 55, 62 paging,, 61 paging physical context, 58

Reset, 202 call release, 120 circuit,, 120 circuit

Q Q1 Interface, 199 Q3 Interface, 38 Multimanager, 25, 38, 158 Quality, handover, 92 Quality intercell, handover, 94 Quality intracell, handover, 94 Queueing, 69 inqueue, 69 priority, 70

Resource usage, on demand, 24, 155 Restart, 202 RSL, 197 RXLEV, power control, 134 RXQUAL, power control, 134

S SBL, 184, 205, 210 BTS_TEL, 196, 207, 208 DTC, 197 RSL, 197 states, 201205 TRE in BTS A9100, 207 SCCP, release, 115, 123 Sectored site BTS, 175 cells, 175 Selftest, 201 Service Improvement Features, 23, 146 new, 25, 158 Short Message Service, cell broadcast, 22, 144

R Radio link failure, 126 link measurements, 132 measurements, 90 power control, 22, 131 resource release, 116 Radio and link establishment, 50, 61 Radio Resource Management, 40 Rate adaptation, 169 Raw, counters, 213 Reception, discontinuous, 142 Release See also Call release MSC normal, 115 radio resource, 116

238

/ 240

Signal quality, 133 strength, 133 Silence Indication, discontinuous transmission, 138 Snapshot, jobs, 213 Software download, 201 failure,, 197 failure start, 201 Software version audit, 220 Speech Alaw encoding, 167 digital encoding, 165 error correction, 165 handling, 165 interleaving, 165 multiplexing, 166 Spontaneous messages, 193


Index

State audit, 220

Transcoder Submultiplexer Controller. See TSC

States In Traffic, 203 not In Traffic, 204

Transmission discontinuous, 138 subsystem, 29

Status changes, 201 inspection, 216

Transparent data, 169 Fax Group 3, 87

Submultiplexer,, 29 Submultiplexer

TSC, 29 alarms, 200 O&M role, 188

Subscriber identity module, 32 Supplementary services, calls, 19 Synchronous, handover, 100 System information messages, 46

T Target cell evaluation, 99 list, 91 TC, 29 alarms, 127

TSS, Transmission Subsystem, 29 Types of Cell Environments, 23, 146

U Umbrella, Umbr ella, cell, 178 Usage state, on demand, 24, 155 User traffic, handling, 163 User traffic calls, 19

V

TCU failure, 195 overload action, 108

V.110 V .110 protocol, 168

Telecom, parameter modification, 222

Virtual Raw Measurements, 214

Telecommunication layers Application, 39 Transmission, 39

Visitor Location Register, 32

Telecommunications Management Network. See TMN Temporary Mobile Subscriber Identity, 35 Terminal Control Unit. See TCU

Voice Activity Detection, discontinuous transmission, 22, 139

W Warning,, mediated, 213 Warning

Thresholds, microcell, 179 Timing advance, 133 TMN, 37 Token bus, 199 Tracing call, 211 IMSI, 212 Traffic channel, 44 Transcoder. See TC Transcoder Pools, 26, 159


X X.25 redundancy redundancy,, 24, 153 link transfer, 154

Z Zones concentric cell, 174 overlap, extended cell, 176

239

/ 240

Index

240 / 240


Co C ov ve er r S Sh he ee ett Status

Released

Class_1 Class_2

Alcatel 900/1800 BSS Descriptive Document

Class_3 Class_4

Short Title

System Description

Doc ID

Main_Title Sub_Title DOCC MMCC

System Description

System Guide

CRN No

H i s t o r y 01 950401

06 980130

07 980519

Comp. Dept. Name

CITVY GCD-C M. Ridealgh

CITVY GCD R. Gallon

CITVY GCD R.Gallon

Comp. Dept. Name

CITVY GCD-C M.Ridealgh

CITVY GCD R.Gallon

CITVY GCD R. Gallon

Comp. Dept. Name

CITVY GCD D. Lé

CITVY GCD D. Lé

CITVY GCD D. Lé

Edition Date Change Note Operator:

Originator:

Appraisor:

Exte Ex tern rnal al His Histo tory ry of La Last st Ed Edit itio ion n

Inte In tern rnal al Hi Hist stor ory y of La Last st Ed Edit itio ion n New Edition for release release 4.2. Added features, features, reorga reorga nized chapters 1 and 5.


1 / 240

Co C ov ve er r S Sh he ee ett Distribution List Internal Code company code

chars

External Code department

name

Site 1

full name 5/12/15

Abstract

Review


47936945 BSS System Description Alcatel System

Recommend Documents