GMSC ARCHITECHTURE_REV5.0_29.03.05

GMSC ARCHITECHTURE

Specification No.: C1-NW2-000-31

5.0 29.03.05Implementation

Ajay A MathurN.Matange / Shilpa Phadke / Vchandra sekhar

Amitabh Mukhopadhyay/ Arun Sur

4.0 01-02-05 CirculationCharu Arora/Ajay A Mathur

N.Matange/ Shilpa Phadke


3.0 14-10-04 Circulation

Charu Arora/Sachin Mishra/Abhinav Iyer



2.0 19-06-04 CirculationCharu Arora/Sachin Mishra



1.0 26-12-03 DraftSachin M/ A Thiagrajan/Shilpa Phadke

N.MatangeAmitabh Mukhopadhyay/ Arun Sur

Rev Date Version Prepared By Reviewed. By Appr. By

Reliance Infocomm GMSC ARCHITECHURE

Revision History

Rev 1.0 to Rev 2.0Document changed due to introduction of GMSC meshing and therefore there is a change in philosophy of call routing, primarily for Inter-circle Off-Net and On-Net calls.

Rev 2.0 to 3.0With architecture proposed in Rev 2, the inter circle Off-Net, On-Net and Loop Around traffic was routed through GMSC and it was found that the GMSC's were getting loaded. Moreover, as the number of MSC's and the traffic in the network grows, the number of GMSC's that will be required to support traffic as per architecture in Rev 2 would be quite large and actually look irrational. Hence, a change in philosophy of call routing via GMSC is proposed to be adopted, whereby MSC's/GMSC's and ILT's can be used to the best of their capacity and efficiency.The prominent changes proposed in this document with respect to the previous version are as stated below:

1. Loop Around E1s to be restored with MSC (i.e. LOCREQ for intra circle calls is done by MSC), in place of routing this via GMSC's

2. Inter MSC traffic to be restored, in place of routing this traffic via GMSC's.3. Inter circle Off-Net (covered NLD) traffic to be given to the ILT from MSC,

in place of routing this traffic via GMSC’s.4. International outbound traffic to be routed from MSC’s, directly to ILT’s (in

place of routing it via GMSC’s)

Rev 3.0 to Rev 4.0Document has been revised to include the IUC Implementation 3 dated 1st

February 2005 for change in routing of calls for Inter Circle In Roamers.

Rev 4.0 to 5.0

a) The fact that all TLDN numbering has been changed to ‘93’ series numbers has been considered.

b) The fact that migration to ‘93’ numbering for all FM users, across all circles, has been completed: has been considered. Also the fact that ‘LM’ subscriber shall have numbers only from ‘31’ series has been considered.

10/04/23 Wireless Planning & Engineering Page 2 of 35


c) The actual implementation in the network (MSC/GMSC/ILT etc), based on “not complicating” much the routing tables/digit analysis, has now been incorporated in this version.

d) As per new IUC implementation, calls originated by National and International inroamer, to Intra circle Off-Net, Inter circle Off-Net and International destination, would be handed over L 1-TAX on separate TG.

Some examples of such changes are:

1) All Inter circle On-Net calls are routed ‘out’ of the MSC towards the circle GMSC irrespective of whether the dialled number is a wireline no. FWT/FWP no. or a LM no. (‘93’ number of distant circle is, of course, routed to the GMSC of the originating circle GMSC). The GMSC separates the traffic destined towards FWT/FWP etc, and routes the same to GMSC of distant circle, it thus, also an Inter circle wireline number to distant ILT.

2) Similarly, an ILT routes the Inter circle calls destined to a ‘93’ user of a distant circle directly over the ”ILT (D) - Destination circle GMSC” connection; whereas it routes the traffic destined to distant circle FWT/FWP, or an LM user, on the ’ILT-ILT connection mesh’. The distant circle ILT then route such traffic to the terminating circle’s MSC’s/GMSC’s.

d) Inter circle On-Net calls, irrespective of their originating source (“93” user, or LM user or an FWT/FWP/STD PCO user) get routed to circle GMSC, then

i) To the destination GMSC, if the destination is a CDMA user. ii) To the destination ILT, if the destination is a wireline user of the other (distant) circle.

Note: This is now possible, since the 16 KHz charge rate would now be supplied to the MSC directly by WIN (with UR6 implementation in Comverse WIN, & R23 SU6 implementation in Lucent MSC’s)

As such, in this revision, these changes, in routing, have been incorporated.

Previously Inter circle calls originated by STD PCO’s had to be routed via originating circle ILT even if those are Inter circle On-Net calls (including wireless to wireless, or wireless to wireline).

INDEX



1.1 Scope....................................................................................................5

1.2 The System............................................................................................5

1.3 Network Topology & Connectivity.........................................................6

1.4 Call Routing...........................................................................................7

1.4.1 ON Net’ Wireless to Wireless......................................................8(a) Intra circle calls (for Full Mobility and Limited Mobility customer)....8(b) Inter circle wireless-to-wireless calls (for Full Mobility and Limited Mobility customer)..................................................................................9

1.4.2 ON Net’ Wireless to Wireline calls..........................................10(a) Intra SDCA / Intra Circle................................................................10(b) Inter Circle......................................................................................11

1.4.3 ON Net’ Wireline to Wireless calls............................................13(a) Intra Circle......................................................................................13(b) Inter Circle......................................................................................14

1.4.4 ‘OFF Net’ Mobile to Land calls (i.e. O/G calls)..........................15(a) Intra SDCA & Intra circle (Off-Net Calls):..................................15(b) Inter Circle - Mobile to Land (Off –NET calls)..........................17

1.4.5 Incoming Off Net calls (Intra Circle)................................................19(a) Intra Circle, off net, Incoming calls:................................................19(b) Incoming Off-Net calls (Inter Circle)...............................................20

1.5 Call Routing to Private POIs................................................................20

1.6 Call Routing for International traffic.....................................................21

1.7 Adjunct calls...........................................................................................21

1.8 Handling of Traffic Originated by Inter Circle In Roamers...................22

1.9 Handling of Call Forwarding in G-MSC................................................23

1.1 Scope



This document provides the architecture of Gateway Mobile Switching Centre (GMSC) in the Reliance CDMA network and its connectivity/call routing with external Network i.e. other operators, Reliance’s wireline switches (ILT) etc.

Note: This architecture is used as a design basis for calculating the number of GMSC’s required as on 31.03.2006 (i.e. A.O.P 2005-2006)(Refer Specification Number: Design Basis Document: C1-NW1-000-017). With this architecture, the number of GMSC’s that will be required, are summarised in Annexure-3.

1.2 The System

The GMSC’s are deployed in the network

To handle the IS – 41 traffic (mainly terminating calls). To reduce the Tandeming load in the MSC due to POI. To reduce load on ILT’s for incoming calls in FM scenario (i.e.

93 numbering scheme).

Ericsson GMSC has connectivity capacity of 1892 E1s. Of these, 1512 E1s are engineered in Optical form (as 24 STM1s) and 380 E1s are engineered in electrical form.Out of 380 E1s, only 128 E1s (which are ‘true’ electrical E1s, and not de-multiplexed from the optical STM-1 interface) can be configured with R2MFC signalling.

The GMSC will handle following types of traffic:

Mobile terminated traffic from:

o PSTN (Incumbent BSNL/MTNL) from TAX POIo Other licensed Basic Service Operators (BSO) in circleo GSM Service Providerso ILT (local) -Wireline traffic, ILD traffic.o ILT (distant)- Off-Net NLD traffic, plus On-Net wireline to

wireless Inter-circle calls destined to FM users.o GMSC from the other circle, On-Net NLD (wireless to

wireless) Traffic.

Outgoing traffic to



o PSTN (Incumbent BSNL/MTNL) to TAX POIo Other licensed Basic Service Operators (BSO) o GSM Service Providerso All the Adjunct Traffic (progressively), except Call Centre

Traffic.o GMSC (Distant) – On-Net Wireless to Wireless traffic

(Refer Annexure 3)o ILT (Distant) - On-Net wireless to (Inter circle) wireline

traffic.o ILT (Local)-Intra circle On–Net wireless to wireline traffic

plus FWT/FWP/STD PCO originated traffic

Some very “high Level” guidelines for routing are given in Annexure-4.

1.3 Network Topology & Connectivity

GMSC communicates with other network elements, e.g. S-HLR, via a pair of STP's.

The signalling with respect to the voice trunks between the GSMC to other MSC’s (& ILT, POI's, etc) will be Indian ISUP version .In some rare cases, the signalling with PSTN/GSM/BSO could be Indian R2-MFC.

GMSC has the following connectivity (voice)

Connectivity towards PSTN TAX_POIConnectivity towards MSC’s of the circleConnectivity towards GMSC’s of other circles Connectivity towards ILT of the same circleConnectivity towards ILT’s of other circlesConnectivity towards Adjuncts (IP-IVR, OTAF-IVR, VMS)

Figure-1 Gateway Network Architecture


OFF-NET+ ON NET CALLS INTERCIRCLE (Note2)

I/C

G

M

S

C

O/G

ILT (D)

ILT (L)

POI’s

PVT POI’s

PVT POI’s

FM POI’s (MTNL/BSNL)

MSC of the same CIRCLE (mainly ADJUNCT traffic + traffic to POI’s + Overflow)

MSC 1

MSC 2

MSC N

RIM INTERCIRCLE (Note1)

ILD

L1 TAX

L2 TAX

FIXED OPERATOR

NLD (OTHER)

ILD (OTHER)

L1 TAX

L2 TAX

WLN – SAME CIRCLE

MOBILE OPERATOR

ILT (L) (FWT/FWP/PCO +ORIG OFFNET + ILD + OVFL

GMSC (D)

GMSC (DISTANT) RIM INTERCIRCLE “CDMA to CDMA”


Note 1: Traffic destined to a CDMA user (FM, or LM or FWT/FWP) would be coming in, from distant GMSC.



Note 2: Distant ILT shall route NLD traffic (“collected “by it from various Off- Net originations destined for FM CDMA subs). It will also route Inter circle On- Net traffic originated by wireline users destined to “93 (FM)" subscribers of the destination circle.

1.4 Call Routing

The call flows with GMSC can be described as under:

1.4.1 ‘ON Net’ Wireless to Wireless (i.e. CDMA to CDMA)

(a) Intra circle calls (for Full Mobility and Limited Mobility customer)

Primary Route

These are the calls, originated by Reliance wireless users.

1(a) Limited Mobility case (Called party number is an LM number [31]): All Inter SDCA/Intra Circle ‘ON Net’ calls originating in an MSC (i.e. when called LM number is NOT served by the originating MSC) shall be routed on inter-MSC trunks to the “appropriate” MSC. The terminating MSC shall do LOCREQ and terminate the call.1(b) All cases where the called LM number is served by the originating MSC, the MSC itself shall perform LOCREQ, and terminate the call. If it is a local termination (call within same MSC), it will get completed locally. If the TLDN is given by HLR, call will be routed on inter-MSC trunks.

2 Full Mobility Case (Called party number is an FM number- 93 NUMBER): Here, LOCREQ shall be performed by the originating MSC and the call shall be completed locally or via TLDN routing on inter-MSC trunks.

3. Traffic destined to FWT/FWP users -This case shall be treated similar to 1(a) &1(b).

Secondary Route



Overflow for loop around trunks (in case of Lucent MSC’s) and for inter-MSC trunks shall be given to GMSC (if existing). The GMSC then shall do LOCREQ and terminate the call. Similarly, overflow for Intra circle TLDN's shall be given to GMSC’s (if present).

Note 1: For any other vendor’s MSC (other than Lucent, e.g Nortel or Telos), overflow can be provided only for inter-MSC trunks, as there is no concept of loop around trunks (in such ‘other’ MSC’s) for a mobile-to-mobile call.

Note 2: In circles, when GMSC does not exist, there shall be no overflow for loop around trunks; overflow for inter-MSC trunks (including TLDN's) shall be via Circle ILT (Local).

(b) Inter circle wireless-to-wireless calls (for Full Mobility and Limited Mobility customer)

The inter circle wireless to wireless call (destined to either a ‘93’ number in the distinct circle, or to FWT/FWP or an LM subscriber in the distant circle) would be delivered from originating MSC to the GMSC of that circle. The originating circle GMSC would analyse the called number and route all traffic, other than that destined for wireline On-Net calls of distant circles, to the GMSC in the terminating circle via the GMSC mesh. GMSC in the terminating circle shall do LOCREQ and terminate the call.

For cases where the terminating circle does not have a GMSC at all, the originating MSC would route the call to the ILT in the originating circle, and the call shall get routed, in turn over the ILT-ILT mesh. Alternately, the originating MSC would route the call to the “nodal/nominated GMSC of an adjacent circle”.For example, Haryana MSC’s, would route such calls to Jallandhar (Punjab) GMSC, which would “act” like Haryana GMSC for all practical purposes.

Secondary Route



If for a Wireless-to-Wireless Inter circle call, MSC-GMSC route is unavailable, the MSC shall route the traffic to circle ILT as an overflow, which will deliver it -

(a) To the distant GMSC for calls destined to “93” users.(b) To the distant ILT, for calls destined to FWT/FWP/LM Users.

Overflow route for GMSC mesh shall be as per Annexure-1

Note: A typical wireless to wireless Inter circle call, destined to a “93” user in the distant circle.

1.4.2 ‘ On-Net’ Wireless to Wireline calls

(a) Intra SDCA / Intra Circle

Primary Route: -


HLR QRY

GMSC

M SC

ILT

P111

GMSC

ILT

MSCC

Circle 1 Circle 2

S111

S3

P2

P311

GMSC Mesh

S2


The originating MSC shall route the call directly to the circle (local) ILT for termination. If there is more than one ILT in a circle, the MSC shall route the call to ‘right’ ILT based on digit analysis.

Secondary Route: -

In case the direct route between the MSC & ILT has failed or is congested, then O-MSC shall route the calls to the GMSC (if available) as next choice and second MSC as second choice overflow. The GMSC or the second MSC would “Transit” the call further to the ILT as second choice overflow.

If the second MSC to ILT or GMSC to ILT route too is unavailable, then the call will fail.

Note: A typical Intra SDCA, wireless to wireline On-Net call.

(b) Inter Circle

Primary Route: -

The originating MSC, shall route the call to the GMSC in the originating circle (if available), which in turn, should route the call to the distant ILT in the terminating circle.


GMSC

MSC1

ILT

MSC2

P1

S1

P1

S2

S2


In case the originating circle does not have a GMSC, the originating MSC would route the call to local ILT & the call shall then get routed in the ILT-ILT mesh.

In case there is no GMSC in the originating circle, and in case the originating MSC routes calls to another “nodal/nominated GMSC’ of another nearby circle (example Haryana MSC could route such calls to Jallandhar GMSC - - -). See 1.4.1(b), then the ‘adjacent circle GMSC’ would practically act like it were the GMSC of originating circle.

Overflow Route

In case the route between the originating MSC and the circle GMSC is unavailable, the MSC would route the traffic to the “Local ILT “, which will then carry the traffic over the ILT-ILT mesh.

In case the direct route between the local ILT & distant ILT has failed or is congested, then these calls shall get routed over the ILT-ILT mesh to another ILT from where the call would be handed to the concerned terminating ILT.

Note: A typical Inter Circle, Wireless to Wireline call.


GMSC

M SC

ILT

P1

ILT

S1

Circle 1

Circle 2Circle 1

S3 S4

P3

P2

ILT-ILT mesh


1.4.3 On-Net’ Wireline to Wireless calls

(a) Intra Circle

Primary Route

The Originating ILT shall hand over the call to the circle GMSC - when the call is destined for an FM (93) user. If more than one GMSC exists, then ILT shall route the calls on equal priority basis to all GMSC’s.

In case the destined number is an LM (31) number, or an FWT/FWP number, the ILT should route the call to the “right” MSC.

If a circle does not have a GMSC, ILT should route the call to all MSC’s in circle on equal priority when called number is FM and to “right” MSC when called number is LM or FWT.

Secondary Route

If the primary route (ILT to local G-MSC) is unavailable, ILT should route the call, on the overflow route as under:

1) To all MSC’s on equal priority if called number is FM.

2) If the primary route (ILT-right MSC) is unavailable for cases when destination is an LM/FWT/FWP user, ILT shall route the call via GMSC.

(b) Inter Circle

Primary Route

The call originates from an ILT, where digit analysis of the dialled digits shall take place. Based on the analysis, the Originating ILT shall hand over the call to the GMSC in the terminating circle, for calls destined to terminate onto a “93” number; for calls destined to either LM number or FWT/FWP users, ILT shall route these over “ILT-ILT mesh. The ILT of the terminating circle shall route the call to the GMSC (if available) in the terminating circle or to the MSC of the circle as described in 1.4.3(a).



If more than one GMSC is serving the (terminating) circle then the calls will be handed over on equal priority basis to all GMSC’s.

The terminating GMSC shall carry out the Loq-Req and via TLDN, shall handover the call to the serving MSC. In case, the call is handed over to the right” MSC (or all MSC’s as overflow), then Loq-Req shall be carried out by the MSC.

Secondary Route

If the primary route (i.e. ILT to distant G-MSC) has failed, originating ILT shall route it to distant ILT (of terminating circle) over the ILT-ILT mesh. The terminating circle ILT shall then route the call to the terminating GMSC, which shall then do LOCREQ and terminate the call.If terminating ILT to terminating circle GMSC route is unavailable/congested, ILT shall route the call to MSC’s as described earlier under 1.4.3(a).

INTER CIRCLE ON NET- WIRELINE TO ( 93) WIRELESS

Note: A typical wireline to wireless Inter circle call destined to a “93”subscriber in the distant circle.


Circle 1

M SC

ILT

S1

P1

Circle 2

GMSC ILT

S2

P2


1.4.4 ‘Off-Net’ Mobile to Land calls (i.e. O/G calls)

(a) Intra SDCA & Intra circle (Off-Net Calls):

Case 1. All FM POI’s with GMSC only

If the FM (UASL) POI is available only at GMSC, then, for the outgoing calls, the MSC shall perform digit analysis as usual. Based on the analysis, the call (originated by FM user) shall be routed to the GMSC, which, in turn routes it to the POI. Depending upon digit analysis, G-MSC shall route the call to the approximate L-2 TAX, which serves the terminating SDCA.

Note: Since the wireless LEX POI’s shall continue to be on ILT and/or MSC, calls originated by LM users shall get routed to the respective MSC/ILT. Call originated by FWT/FWP user shall get routed to local ILT from MSC since “Wireline” POI’s are connected to only ILT’s; GMSC shall not be involved in these call cases.


ILT

GMSC

MSCMSC

L2/L1 Tax POI

LEX POI/Wireline (FWT/FWP) POIs

LEX POI

P2

P1

P1

P2

P1

P3

LEX POIs


P1: FM Originated (POI on GMSC)

P2: LM/FWP/FWT originated calls (POI on ILT)

P3: LM Originated (POI on one of MSC’s)

Note: A typical Intra circle OFF NET call, originated by an FM user, destined

to a BSNL number, when POI is connected to GMSC.

Case 2. FM POI’s with an MSC

For the outgoing calls, MSC performs the digit analysis (as usual). Based on the analysis, the call shall be routed to the POI trunks directly. If the originating MSC does not itself have the POI, the call shall be routed on inter-MSC trunks to the “POI bearing MSC”, which will, in turn “tandem” these calls to the POI. .Overflow for IMT shall be via GMSC which will tandem calls to “POI bearing MSC”.

Routes to POI themselves shall have no overflow (the only option is POI connectivity has to be augmented, or diversity has to be built in the transport network etc)

P1

Note: A typical Intra circle Off-Net call to BSNL number, when the POI is connected to an MSC (and not to GMSC).


POI

GMSC

MSC MSC

P1

P1S 1


(b) Inter Circle - Mobile to Land (Off –NET calls)

Case 1. (a) Inter Circle (destined to NLD Covered Towns)

Primary Route

The call originates in the MSC where the digit analysis of the dialled digits shall take place. Based on the analysis, the call shall be routed by the originating MSC, for all NLD covered towns, to the originating circle ILT. Further, such calls shall be carried over the ‘ILT-ILT’ mesh, and finally delivered over the “NLD POI’s” at the terminating circle.

The destination for such calls would typically be a BSNL number, but could also be another BSO number or another GSM operator’s cell number etc.

Secondary Route

If the primary (local ILT to distant ILT) link fails or is unavailable, ILT shall route these calls to another ILT over the ILT-ILT mesh from where the call shall be eventually handed over to the terminating ILT.

If MSC to originating ILT route is unavailable, originating MSC shall route it to GMSC or other MSC in circle as overflow, to be finally handed over to local ILT as first overflow choice route.

There would be no further overflow. In other words, such calls shall not be routed directly to distant ILT (even if such connective between “GMSC and distant circle’s ILT” exists).



Note: A typical Inter circle call destined to a “covered” NLD destination (e.g.

BSNL SDCA where Reliance is ‘present’ as NLDO.)

Case 1. (b) Inter Circle (destined to NLD Uncovered Towns)

Existing routing arrangement will continue, i.e. all traffic meant for NLD uncovered town will be sent to LDCA TAX of the originating subscriber’s SDCA in case of call originated by limited mobility/ FWT user; and to L-1 TAX, in case of call originated by full mobility users.

Notes: a) FWT originated traffic gets routed to ILT from MSC and gets delivered to BSNL’s appropriate POI over the TG meant for ‘wireline’ traffic.

b) In case of LM subscriber originated call, such calls will be handed over to the L-2 TAX of the originating SDCA via MSC or ILT wherever POI exists.

c) For calls originated by FM users: In case one of the MSC’s has L-1 TAX POI, such calls shall be routed to “POI bearing MSC” on inter-MSC trunks. However all the TAX POI’s (for FM users) will be shifted ultimately to the G-MSC in which case such calls will be routed from MSC to GMSC, and then ‘delivered’ over the FM POI’s, to L-1 TAX.



1.4.5 Incoming Off Net calls (Intra Circle)

(a) Intra Circle, off net, Incoming calls:

Primary route These calls will be handed over (by, say BSNL) to the GMSC (wherever available) either from POI’s or from ILT. If the call comes in, into a GMSC, then the GMSC shall then do a Loq-Req query to the S-HLR, and terminate the call using TLDN directly to the appropriate MSC. If the call comes in, into the ILT (these shall typically be those call that are destined to LM/FWT/FWP users), then ILT shall route further towards MSC/GMSC exactly as described in 1.4.3(a).

Secondary Route (applicable only for ILT to G-MSC)

For calls destined to the FM users if the primary route between ILT to G-MSC is unavailable, ILT shall route the calls to

1) All MSC’s on equal priority basis MSC shall do the LOCREQ and complete the call.

2) For calls destined to LM/FWT/FWP users: The ILT shall route the overflow traffic via GMSC (all GMSC’S equally, in case there is more than one GMSC). GMSC shall do the Loq-Req and complete the call.

Note: As stated earlier, for Full Mobility users, Incoming Off NET calls shall be delivered into Reliance’s Network via L-1 or L-2 TAX of BSNL (as the case may be) at the GMSC (wherever G-MSC exists in the circle).

In the interim period, when all GMSC’s are not commissioned or for a circle where no G-MSC has been planned, these will continue to come in via ILT (rarely), or MSC (mostly) as the case may be (i.e. Wherever the POI exists).

(b) Incoming Off-Net calls (Inter Circle)

The Inter-Circle Off Net Incoming Calls will be (generally) carried by the BSNL up to their L1/L2 TAX at the terminating circle/LDCC. This will then be handed over by the BSNL to Reliance at the POI established (to the GMSC or to the ILT or to an MSC – as the case may be).The details therefore are similar to 1.4.5(a).



.1.4 Call Routing to Private POI’s

All the private operator POI’s of the circle shall be shifted to the GMSC .In the interim period, the existing routing arrangement will continue.Once the POI’s are shifted fully to the G-MSC, both outgoing and incoming calls shall be routed via GMSC.If some private operators (or even BSNL, for that matter) agree to have POI’s additionally with MSC’s directly, then the outgoing traffic shall be routed over such POI’s as primary choice and overflow via GMSC. Incoming calls also would be ‘accepted’ on such MSC POI’s, but the private operators (or BSNL) shall be required to use this only as their last choice route (first choice being via GMSC).

In the reverse direction (i.e. for traffic outbound from Reliance network, into the private operator’s network), similar arrangement shall be done if the private operators establish & commission GMSC’s in their networks.

1.5 Call Routing for International traffic

The Outgoing ILD calls would be handed over from the MSC directly to (originating circle) ILT on a separate trunk group. This international traffic would then be carried over the Reliance’s NLD network to the Reliance’s ILD POP’s etc.The Incoming ILD calls, destined to “93” users, shall be delivered to the GMSC by the local ILT on a separate trunk group. Similarly, the incoming inbound international calls destined to LM/FWT/FWP users, shall be routed by the ILT to the “right” MSC over the separate “ILD-TG”. The traffic from the ILD POP up to the ILT of the terminating circle shall be carried by the Reliance’s NLD network (ILT-ILT mesh).

Overflow for MSC to ILT may be given to GMSC (GMSC shall have a separate “ILD” trunk group to ILT). There will not be any separate trunk group between MSC-GMSC for purpose of international traffic.

1.7 Adjunct calls



All adjunct connections shall be progressively shifted to the G-MSC except the connectivity with customer care, which requires ‘PRI’ connectivity (which is not available in Ericsson G-MSC). In the interim period when GMSC’s are yet to be commissioned, adjuncts calls shall continue to get handled via ILT.

Adjuncts shall be connected to all GMSC’s on regional basis. Refer to Annexure 2 for “GMSC-Adjuncts” connectivity “ as well as for details on overflow routing of outbound calls to Adjuncts.

All adjuncts traffic shall be routed from MSC to GMSC. GMSC shall route it to the adjuncts connected (as per region).Overflow of GMSC to adjuncts shall be given to GMSC of other regions.Overflow for all western region adjuncts traffic shall be routed to Hyderabad GMSC; Similarly, SE region overflow shall be given to Mumbai GMSC.

1.8 Handling of Traffic Originated by Inter Circle “in-roamers”

As per the IUC Implementation 3, dated 1st February 2005, calls originated by roamers (these will naturally be FM users) is to be treated differently than those originated by native (Home) circle FM users.

According to the new IUC requirements, all call “types” originated by an inroamer, namely:a) Intra-Circle Off-Net calls.b) Inter-Circle Off-Net calls.c) International calls, that have to be carried to the International

destination by BSNL/MTNL (as the NLDO/ILDO).would have to be handed over by the MSC/GMSC to the L1 TAX in the circle (where the FM subscriber is roaming) over two separate Trunk Groups, as compared to the homers in that circle, as shown below.


MSC/GMSC

L1 TAX

L2 TAX

Homers: Intra-Circle UASL covered

National Roamers

Homers: Intra-Circle UASL uncovered


Note1: There has to be a separate TG for carrying traffic originating by “National inroamers” and another TG for carrying traffic originated by “International inroamer”.

This is in accordance with the IUC requirement.

However, Reliance’s way of implementation is dependent on the NLD coverage of the destination (as Reliance is, itself, an NLD carrier).

In Reliance, all the above-mentioned types of calls would be handed over to the originating L1- TAX, with the following exceptions:

a) Inter-circle Off-Net calls (originated by inroamer: National or International), which are destined for users in Reliance NLD covered SDCA: these calls would be handed over instead, to the originating circle’s ILT (and not to L1 - TAX).

b) Intra-circle Off-Net (originated by inroamer: National or International) calls to UASL uncovered but NLD covered destination would be routed over to originating circle’s ILT. (Whereas the UASL Uncovered, NLD uncovered would be routed to the L1 - TAX).

c) All international calls (originated by IN-Roamers: national or International) would be handed over to the ILT, which is Reliance’s ILD switch.

This is Reliance’s specific way of implementation. In initial phase however, all the traffic mentioned above would be routed to L1 TAX and the routing of relevant calls to ILT (as described at ‘a’, ‘b’, & ‘c’ above) would follow later progressively.


International Roamers

New TG’s exclusively for roamers (Note1)


1.6 Handling of Call Forwarding in G-MSC

Call forwarding to any Off-Net number shall be disallowed from the G-MSC unless specific agreements exist.Technical feasibility of incorporating this functionality (of disallowing, in GMSC’s, only forwarded calls to Off-Net numbers needs further study).

Annexure-1: (Refer- 1.4.1 ‘b’)

Overflow Route table for G-MSC mesh



Overflow Route

Traffic From Traffic To25% Traffic

25% Traffic

25% Traffic

25% Traffic

AHMEDABADAny Destination BHO DEL HYD BLR

CHENNAIAny Destination HYD BLR BHO DEL

COIMBATOREAny Destination HYD BLR BHO DEL

ERNAKULAMAny Destination BLR HYD BHO DEL

JAIPURAny Destination DEL BHO HYD BLR

JALLANDHARAny Destination DEL BHO HYD BLR

KOLKATAAny Destination HYD BLR BHO DEL

LUCKNOWAny Destination DEL BHO HYD BLR

MEERUTAny Destination DEL BHO HYD BLR

MUMBAI (BOTH GMSC)

Any Destination BHO DEL HYD BLR

PATNAAny Destination DEL BHO HYD BLR

PUNEAny Destination HYD BHO BLR DEL

Traffic From

BANGALORE Traffic To40% Traffic

30% Traffic

30% Traffic

BHOPALAny Destination HYD BHO DEL

DELHI (BOTH GMSC)

Any Destination DEL HYD BLR

HYDERABADAny Destination BHO HYD BLR Any Destination BLR BHO DEL

Note 1: The Traffic Distribution shown above is for the alternate routing arrangement within the G-MSC meshing, when the primary route is unavailable (In case of inter circle ON NET wireless-wireless calls).



Note 2: If there are more than one GMSC’s in a circle, (e.g. Delhi would have two GMSC, as on 31.03.06), then traffic shown above shall be shared ‘equally’ further between GMSC’s.

Example1:In case the route between Ahmedabad G-MSC and (say) Pune G-MSC (primary route) is unavailable, Ahmedabad GMSC amongst Bhopal, Delhi, Hyderabad and Bangalore G-MSC’s will distribute traffic equally (25% each).

Ahmedabad GMSC to Bhopal GMSC, destined for Pune GMSC: 25%

Ahmedabad GMSC to Delhi GMSC, destined for Pune GMSC: 25%

Ahmedabad GMSC to Hyderabad GMSC, destined for Pune GMSC: 25%

Ahmedabad GMSC to Bangalore GMSC, destined for Pune GMSC: 25%

In case the route between Ahmedabad GMSC and both Delhi GMSC’s (which is one of the secondary routes in the above example) also fails, at the same time, traffic would be distributed amongst remaining overflow routes i.e. Bhopal, Hyderabad and Bangalore G-MSC’s equally (33% each).

Ahmedabad GMSC to Bhopal GMSC, destined for Pune GMSC: 33%

Ahmedabad GMSC to Hyderabad GMSC, destined for Pune GMSC: 33%

Ahmedabad GMSC to Bangalore GMSC, destined for Pune GMSC: 33%

Of course, as long as the direct route is available (and not congested either), the traffic shall flow over the direct route.

For example, the traffic from Ahmedabad GMSC to Delhi GMSC shall be routed directly from Ahmedabad GMSC to both Delhi GMSC’s equally over the “GMSC-GMSC” mesh. If there is (for example) congestion on this route, then Ahmedabad GMSC shall route the overflow via Bhopal, Hyderabad and Bangalore equally at 33% each.

Note 2: Infinite traffic loops have to be avoided by suitable engineering.



Example1: As stated earlier, in case the route between Ahmedabad G-MSC and Pune G-MSC (primary route) is unavailable, traffic will be distributed amongst Bhopal, Delhi GMSC-2 & 3, Hyderabad and Bangalore GMSC’s equally (25% each: with 12.5% each).

In case the route between Ahmedabad GMSC and both Delhi GMSC’s (which is one of the secondary routes in the above example) also fails at the same time, traffic would be distributed amongst remaining overflow routes i.e. Bhopal, Hyderabad and Bangalore G-MSC’s equally (33% each). Now, if there is congestion on “Delhi GMSC-Pune GMSC” trunks, then Delhi GMSC should NOT route any traffic to Ahmedabad GMSC (as it can result in ‘looping’ of traffic).

The infinite traffic loops shall be avoided by applying the following logic:

The above overflow routing shall be adopted at the ‘originating GMSC’ ONLY IF the traffic has ‘come in’ into the GMSC, from one of its sub-serving MSC’s (i.e. MSC’s of the circle it is serving); if the traffic has come in from any other GMSC, then overflow philosophy described above shall not be applied (thus avoiding infinite looping of traffic).

Annexure- 2: (Refer 1.7)

Overflow for GMSC to Adjuncts Traffic



Overflow for Northern and Western Region Adjuncts Traffic

Overflow for Southern and Eastern Region Adjuncts Traffic

Originating GMSC having direct

connectivity to Mumbai Adjuncts

Overflow in case of failure on primary

route (From GMSC to Mumbai Adjuncts)

Originating GMSC having direct connectivity to Hyderabad Adjuncts

Overflow in case of failure on

primary route (From GMSC to

Hyderabad Adjuncts)

Delhi Hyderabad GMSC Coimbatore Mumbai GMSCJaipur Hyderabad GMSC Hyderabad Mumbai GMSC

Jallandhar Hyderabad GMSC Ernakulam Mumbai GMSCMeerut Hyderabad GMSC Bangalore Mumbai GMSCPune Hyderabad GMSC Bhopal Mumbai GMSC

Ahmedabad Hyderabad GMSC Lucknow Mumbai GMSCMumbai Hyderabad GMSC Patna Mumbai GMSC

Chennai Mumbai GMSC Kolkata Mumbai GMSC

Note 1: Infinite traffic loops shall be avoided, by suitable engineering, as described in Annexure-1

Note 2: When Mumbai gets its 2nd GMSC, the ‘overflow’ shall be split equally between the two GMSC’s.

Annexure -3

GMSC Justification

GMSC Capabilities – Ericsson:

Erlang Capacity – 28,000 E (I/C + O/G)



BHCA capacity of a G-MSC = 1.23 Mn

The traffic to be handled by GMSC’s is as follows:

Mobile to PSTN (I/c and O/G)Mobile to other operators (I/c and O/G)Mobile to TAX (I/c and O/G)Inter- Circle ON NET WIRELESS to WIRELESS trafficTraffic to the AdjunctsOverflow traffic

Using the subscriber numbers per circle, the total traffic (both BHCA and the Erlangs) to be handled by a GMSC (for the above-mentioned traffic types) is found out & the numbers of GMSC’s needed to handle that traffic are calculated.

FOR J&K, GMSC is NOT proposed.

Total number of GMSC’s needed, as on 31st Mar 2006, are as follows:

Total Number required as on 31st March 2006 = 18Number of GMSC’s existing on date (Feb 05) = 14Additional GMSC’s to be ordered (part of AOP 05-06) = 4**

** 2 GMSC’s pending (only 14 ordered, whereas 16 were planned/budgeted) from last budget (2004-2005) will be ordered, from the last budget itself, leading to additional requirement of only 2 GMSC’s from this budget.

The distribution of GMSC’s across various circles shall be as per the table below:

Circle

GMSC already existing (in Feb

05)

Additional GMSC’s required

Total GMSC’s

(as on 31-03-2006)

AP 1 0 1



Bihar 0 1 1Chennai 1 0 1

Delhi+NCR (See Note 3) 1 1 2

Gujarat 1 0 1Haryana 0 0 0

HP 0 0 0Karnataka 1 0 1

Kerla 1 0 1Kolkata 1 0 1

MP 1 0 1Maharastra 1 0 1

Mumbai (See Note 3) 1 1 2Orissa 0 0 0Punjab 1 0 1

Rajasthan 0 1 1TN 1 0 1

UP (E) 1 0 1UP (W) 1 0 1

WB 0 0

J&K0

00

20 14 4 18

Note 1) Thus, as on 31.03.2006, the circles that will NOT have any GMSC will be:

HARYANA

HPORISSAJ&KWest Bengal

Note 2) Only Mumbai and Delhi Metro Circles shall have 2 GMSC’s each.

Note 3) The present Lucent GMSC’s existing in Mumbai, and Delhi have NOT been counted as these are, each, getting converted to MSC’s during 05-06.



Annexure –4

(Ref. Section 1.2)

High Level Guidelines for Call Routing

1.Mobile (CDMA) Originated calls: -



a) Off-Net Intra circle calls, originated by a FM user, shall be routed to the circle GMSC, on the appropriate POI (e.g. L2 TAX of the dialled LDCA in case the call is destined to a BSNL; to GSM operators GMSC, in case the cell is destined to a GSM user) etc.In case there is no GMSC in the circle, the call should be routed out via “POI Bearing MSC” (which ‘transits’ the call)

b) Off-Net Intra circle, calls originated by either an LM (level 31) user, or FWT/FWP etc, would get routed via the originating circle ILT, which would then route it to the appropriate POI {both LM & wireline POI’s are expected to be terminated onto ILT (for BSNL POI’s}.

However, in case the destination is a “non BSNL” number, the call could get routed via GMSC/MSC where the appropriate POI (for LM or FWT originating traffic) might be connected.

c) Calls destined towards customer care should be routed via circle ILT.Call destined to other adjuncts (IP-IVR, OTAF-IVR, VMS) shall be routed via circle GMSC (or via a “nodal” MSC, in case there is no GMSC in the circle).

d) Call destined to the international destination (ILD) calls shall be routed to the circle ILT, on a distinct TG..

e) Calls destined to Off-Net, BSNL inter circle no’s, for those (destination) SDCA’s that are “NLD covered by reliance” shall be routed via circle ILT.

Note: that IN NO CASE, call destined to OFF NET users shall be routed from one circle to another except via originating circle ILT & then Via ILT-ILT mesh.In specific, GMSC of a circle shall NEVER route an Off-Net Inter Circle call directly to the distant

f) Calls destined to “non – NLD covered” destinations shall be routed via GMSC (or POI bearing MSC), from which they would be routed out to the L1-TAX of BSNL.Even Intra circle calls, destined to “uncovered” SDCA’s (i.e. POI not existing with the L2 -TAX) shall be routed similarly.

g) Calls originated by inroamers (i.e. typically”93” users from other circles; but valid for international inroamers too).

(Note: Level “31” LM users & FWT/FWP users cannot roam anyway).



h) On-Net Inter circle calls, originated by any type of wireless user, shall be routed via the (originating) circle GMSC.

GMSC of the originating circle shall “segregate” the traffic destined to the CDMA user (“93” or LM or FWT/FWP) and route it on GMSC-GMSC mesh; it will route the traffic destined for the distant wireline Inter circle user, to distant ILT.

For circles not having a GMSC, the originating MSC shall either route the call to originating circle ILT or via a “nodal /nominated “GMSC of an adjacent circle (e.g. Haryana originated calls would be routed via Jalandhar GMSC)

i) Intra circle CDMA – CDMA calls shall be handled by the originating MSC (it will carry out the LOC REQ) & then if the call turns out to be Inter MSC/Intra circle call, the TLDN call shall be routed through Inter MSC trunk. (If it turns to be an inter circle call, the “inter circle TLDN” shall be routed as any other Inter circle On-Net call would get routed, if it turns to be an intra MSC call, it will anyway terminate locally).

2. Mobile (CDMA) terminated call, and treatment of TLDN by NE’s other than GMSC/MSC (say ILT)

Note: Only certain important & most common types of call cases are covered below.

a) International incoming calls that have been carried by Reliance, as ILDO shall be delivered by the terminating circle ILT into

i) The GMSC’s of the terminating circle, when dialled no is an FM (93) number,

ii) The correct MSC, based upon the dialled SDCA STD codes (when destined for LM, or FWT/FWP users)

“These calls shall always be delivered in, using a separate and distinct TG.”

b) ILT of a circle shall route ON NET Inter circle calls to distant GMSC only when a GMSC exists in the terminating circle, and the dialled number is a “93” number

For cases where the dialled Inter circle ON NET number is a LM (Level 31) no, or a FWP/FWT no., call shall be carried on the ILT-ILT mesh; the terminating circle ILT shall route such traffic to the “right MSC”.



d) An ILT shall analyse the dialled digits “93” number to distinguish between

I) TLDNII) Normal, customer number.

Only in four metros (Mumbai, Delhi, Chennai, Kolkata) and in those circles which do not have a GMSC.

In such cases, the ILT shall route the calls that have a “TLDN” as B-party number, to the right MSC. In all other cases, ILT shall deliver the call into the terminating circle’s GMSC, which will TANDEM (transit) the call to the right MSC.

NOTE: In future, the ILT’s of the other four major metros circles namely AP, Karnataka, Gujarat, Maharastra (Banglore/ Hyderabad/ Ahmedabad / Pune) too may carry out “93” analysis to distinguish between TLDN series & normal numbers and route the traffic accordingly.

e) Call originated by Intra circle Off-Net users shall normally be delivered only via

i) Circle GMSC (or POI bearing MSC) when the destination is an FM”93” number OR

ii) The ILT, in case the destined number is a LM (level 31), or FWT/FWP number.

3. Wireless NE’s acting as TANDEM switches for Off-Net NLD traffic, or traffic destined for Reliance wireline users:

a) Such cases shall be rare & exceptions.b) This might normally happen only for non BSNL Off Net callers, who may have their NLD (i.e. when they are NLDO’s) POI’s with GMSC (as the bulk traffic destined towards Reliance, at this point in time, is only for CDMA users). In such cases, GMSC’s may TANDEM the calls when destination is a wireline Reliance number.

c) Certain BSNL NLD POI’s (Reliance as NLDO) may be connected to some CDMA MSC’s (like Andman Island- - -, Telos MSC). In such



cases, NLD traffic destined to BSNL users could be transited via a CDMA MSC/GMSC.




Documents

GMSC ARCHITECHTURE_REV5.0_29.03.05