Feature MSRN Allocation Enhancement[1]

FEATURE 906MSRN Allocation Enhancements

DN00232838 © Nokia Corporation 1 (24)Issue 10-0 en Nokia Proprietary and Confidential

FEATURE 906 MSRN Allocation Enhancements

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2 (24) © Nokia Corporation DN00232838Nokia Proprietary and Confidential Issue 10-0en

Contents

Contents 3

List of figures 4

1 Introduction 5

2 Benefits for the operator 7

3 Description of the feature 93.1 Requirements for using the feature 93.1.1 Software 93.1.2 Hardware 93.1.3 Products 93.2 Functionality 93.2.1 General 93.2.2 Files 113.2.3 Parameters 113.2.4 Statistics 113.2.5 Charging 113.3 Capacity 113.4 Restrictions 123.5 Related and interworking features 123.6 Compliance 12

4 Interfaces 134.1 Operator interfaces 134.1.1 MMLs 134.1.2 Alarms 144.2 Subscriber interfaces 174.3 External interfaces 17

5 Main changes in the feature 19

References 21

Glossary 23



List of figures

Figure 1. MSRN allocation example 1 10

Figure 2. MSRN allocation example 2 10


Introduction

1 IntroductionFeature 906: MSRN Allocation Enhancement consists of two parts, a generic andan optional:

1. It removes the former restriction that the last digit of a Mobile StationRoaming Number (MSRN) indicates the VLRU unit, which reserved theMSRN in point. Since then all the MSRNs are available in the MSC. Thispart of the feature is generic.

2. It provides the possibility to allocate MSRNs based on the calledsubscribers' registered Location Area (LA). LA-based functionality givesyou the ability to assign an MSRN group to one or several location areas.One MSRN group can be divided to several MSRN ranges. It affects theELE, ELO, and WVC MML commands. This part of the feature is optional.

The new functionality is internal to the MSC/VLR, and does not cause anychanges to external network elements.




Benefits for the operator

2 Benefits for the operatorWith this feature, you can allocate Mobile Station Roaming Numbers (MSRNs)based on the subscriber's registered location area. The feature allows 100% of theMSRNs to be allocated by removing the restriction that the last digit of an MSRNindicates the VLRU, which allows only 10% of the MSRNs to be allocated.

With this feature, you can view statistical information on MSRN reservationthrough a new service terminal interface.




Description of the feature

3 Description of the feature

3.1 Requirements for using the feature

3.1.1 Software

This feature has no special requirements for software.

3.1.2 Hardware

This feature has no special requirements for hardware.

3.1.3 Products

This feature functions both in the i-series products and the subrack products. Thefunctionality is the same.

3.2 Functionality

3.2.1 General

MSRN allocation principles

There have been only ten MSRN ranges for the whole VLR area. One tenth of theMSRNs per VLRU are usable in the current implementation. This is caused bythe necessity to use the last digit of the MSRNs to identify the VLRU number.This way the MSRN allocation remains as the default functionality.

The new option provides the possibility to attach MSRNs to sets of location areas.It also removes the restriction of using the last digit of the MSRNs to identify theVLRU number. It makes all the MSRNs in the MSC available.

Location area-based MSRN allocation



The location area-based functionality enables you to assign an MSRN group toone or several location areas. One MSRN group can be divided to several MSRNranges. The MSRN allocation example 1 figure gives an example of mapping.

Figure 1. MSRN allocation example 1

Location areas 1, 2, and 3 share MSRN_GROUP_1. The MSRN_GROUP_1 thencontains three separate MSRN_RANGES_(1, 2, 3).

In the same system, there can also be one-to-one mapping from the location areato the MSRN_RANGE, as shown in the MSRN allocation example 2 figure.

Figure 2. MSRN allocation example 2

Unknown location area handling

The unknown_location_area case is in theory possible in a GSM system in someexceptional situations, when:

1. the location area configuration changes are done

2. the subscriber is deleted from the VLR and the PURGE_MS operation fails

3. there is a major software upgrade

Two solutions are provided for handling this special case:

1. defining a specific MSRN group (RNGP=0) for this case

2. checking the subscriber's location prior to the MSRN allocation

The first solution is the default.

LOCATION AREA 1

LOCATION AREA 2

LOCATION AREA 3

MSRN GROUP 1 MSRN RANGE 2

MSRN RANGE 1

MSRN RANGE 3

LOCATION AREA 4 MSRN GROUP 2 MSRN RANGE 4


Description of the feature

3.2.2 Files

There are no files directly visible to the operator.

3.2.3 Parameters

The following parameters are related to this feature:

• The SEARCH_BEF_MSRN_ALLOC parameter determines if the VLRsearches for unknown subscribers prior to requesting an MSRN. Thisparameter can be set through the MML. The possible values are True (T)or False (F).

• The MAX_NO_OF_MSRNS parameter defines the maximum number ofroaming numbers that can be defined in the GSM network and Network-Element-Specific Number File. The possible values are between 10D and5000D.

3.2.4 Statistics

You can view the MSRN statistics through a service terminal. The serviceterminal can do simple statistical calculations on the collected data.

3.2.5 Charging

This feature does not include a charging interface. However, the roamingnumbers can be used as the basis for charging.

3.3 Capacity

• The maximum number of MSRN groups is 51. The range of the MSRNgroup (RNGP) is from 0 to 50. The default value for the MSRN group is 0.

• The maximum number of MSRN ranges in the MSC is set to 100. All the100 MSRN ranges can be defined to the same MSRN group.

• The absolute maximum number of MSRNs in an MSC is 5000. This valuecan be decreased by changing the parameter MAX_NO_OF_MSRNS.

• The minimum number of MSRNs in an MSRN range is 10. The last digitof the MSRN range must be from 0 to 9.



3.4 Restrictions

• The MSRN range has to be allocated in multiples of 10 (for example, 10,20). The last digit of the MSRN range must be from 0 to 9.

• It is not possible to delete MSRNs based on the MSRN group (RNGP).

• It is not possible to modify the MSRN group (RNGP) by using the WVMcommand. The WVD command, followed by the WVC command can be usedto modify the RNGP values.

3.5 Related and interworking features

This feature does not affect other features.

3.6 Compliance

This feature provides an enhancement to an MSC/VLR internal functionality.


Interfaces

4 Interfaces

4.1 Operator interfaces

4.1.1 MMLs

User interface while MSRN groups are supported

The MSRN group handling affects two command groups. The affected commandgroups are the Location Area Handling (EL) and the GSM Network and NetworkElement Specific Number Handling (WV).

There is no cross-checking between these two command groups. You can createa location area to a non-existing MSRN group, and the same applies to the MSRNnumber creation. If a configuration error occurs that a non-existing MSRN groupis going to be used, an alarm is set as an indication. For more information, seeSection 'Alarms'.

MSRN group definition for MSRN range

The MSRN group is an additional parameter to the WVC (Create MSC NumberRange) command.

ZWVC:MSRN=<first&&last>, RNGP=<0,1..MAX>;

The MSRN group is a field displayed while using the WVJ (Interrogate MSCNumber Range) command.

ZWVJ:MSRN;

MSRN group definitions for the location area

The MSRN group is defined with the ELE (Modify Location Area Parameters)command. The default value is 0; it is used if no MSRN group is defined for alocation area.



Note

The ELO (Output Location Area Data) command is modified to output MSRNgroup information along with the location area information. The syntax of theELO command does not change.

For more information on the RNGP maximum value, see Section MSRN capacity.

4.1.2 Alarms

This feature can set the following three alarms.

UNKNOWN MSRN GROUP (2444)

There has been a request to allocate an MSRN for an MSRN group which is notdefined for the system. This can be a configuration error at some location area, orit can be that the MSRN group definition is missing. This is a three-star alarm,because it can cause all calls to fail.

Parameters:

• MSRN group

This is the compared field indicating the unknown MSRN group definedfor a location area.

• Location area code

This field indicates the location area where a particular MSRN group wasassigned.

Instructions for action:

Upon receiving alarm 2444, check the MSRN group definitions defined for thesystem. You must also check the location area for proper MSRN groupdefinitions. Once the MSRN group definitions are correct, the alarm is cancelled.

MML commands:

• Output Location Area Data (ELO command)

Use this command to display the configuration of a given location area.

• Modify Location Area Parameters (ELE command)

Use this command to define the MSRN group for a given location area.


Interfaces

Note

• Interrogate MSC Number Range (WVJ command)

Use this command to list the definition of all MSRNs.

• Create MSC Number Range (WVC command)

Use this command to create the definition of an MSRN group.

MSRN RESERVATION RATIO (2494)

This alarm indicates that some MSRN allocation requests have not beensuccessful for some reason. The most obvious reason is that there are not enoughMSRNs defined in the system. This is a two-star alarm because the condition istemporary. However, the condition can become fatal if the problem is notresolved within a short period of time. The conditions that set the alarm are thefollowing:

1. 80% of the MSRNs are allocated by the MSC.

2. 100% of the MSRNs are allocated by the MSC.

When deleting a group of MSRNs, if any of them are used in the delete group,they are not deleted right away; the MSRN group is given 30 seconds to be de-allocated before being deleted. This means that if reading is taken during thisperiod, the displayed percentage of MSRNs used can be higher than the actualpercentage.

Parameters:

• MSRN group

This is the compared field indicating the MSRN group which had theallocation error.

• MSRN group size

This field indicates the size of the MSRN group.

• MSRN alarm percentage

The percentage limit in the MSRN allocation which existed when the alarmwas set.


Upon receiving the MSRN allocation congestion ratio alarm, you can define moreMSRNs for the system, if possible.

MML commands:



• Interrogate MSC Number Range (WVJ command)

Use this command to interrogate MSRN-related information.

• Create MSC Number Range (WVC command)

Use this command to create more MSRN ranges for a given MSRN group.

MSRN HANDLING ERROR (2449)

This alarm indicates that there is an internal MSRN error. An out-of-order staticMSRN table can cause this alarm. This is a one-star alarm.

Parameters:

• MSRN group

The MSRN group which had the error.

• PLMN INDEX

The PLMN INDEX used in VLR and PLMN Parameter Handling forsubscribers.

• MSRN USE ERROR

The reasons for the erroneous handling.

Possible MSRN USE ERROR values:

• Integrity Check Error (1H): integrity check for MSRN static table failed.

• Hanging Roaming Number (2H): a roaming number has been left hanging,but the internal MSRN handling function released the number.

• Not Enough Space to Add Requested MSRNs (3H): the internal tables ofMSRN handling program do not have enough space to add all the MSRNscreated in the last change.


• Integrity Check Error

When this alarm is set, restart the unit. When the unit is restarted, a newMSRN table will be created for the unit.

• Hanging Roaming Number

Cancel this alarm.

• Not Enough Space to Add Requested MSRNs

Cancel this alarm.


Interfaces

4.2 Subscriber interfaces

There are no effects on the subscriber interface.

4.3 External interfaces

There are no effects on the external interfaces.




Main changes in the feature

5 Main changes in the featureThis feature is implemented on top of M12.




References1. Location Area Handling (EL), Command Reference Manual

2. GSM Network and Network Element Specific Number Handling (WV),Command Reference Manual




Glossary

Abbreviations

MSRN Mobile Station Roaming Number

PLMN Public Land Mobile Network

VLRU Visitor Location Register Unit

Terms

MSRN RANGE MSRN RANGE is a sequence of MSRNs that can be set.

MSRN GROUP(RNGP)

MSRN GROUP consists of one or more MSRN RANGEs. The location area canhave an optional MSRN GROUP parameter that defines the subset of usablenumbers for that location area.

An MSRN group can consist of one or more MSRN ranges. This enables differentnumbering plans to be in the same MSRN group.




Feature MSRN Allocation Enhancement[1]

Documents

compared field

msrn group

existing msrn

registered

location area

integrity

msrn group

service terminal