IWM SC GSM N/W ORIG MS SIM SM-SC. terminating MS. Short msg sender MSC BSS. GSM n/w. Fig. GSM short msg service network architecture

Transcription

1 P. P. MAHALE

2 ORIG MS IWM SC GSM N/W MS SIM SM-SC terminating MS Short msg sender Sms GMSC GSM n/w MSC BSS Fig. GSM short msg service network architecture

3 Sms protocol hierarchy consist if four layer: SM-AL(application layer):- SM-TL( transfer layer):- SM-RL(relay layer):- CM-sub(connection manager sub layer):- Other protocol include telocator alphanumeric input protocol & telocator data protocol. Layers below sub layer are mobility management(mm) & the radio resource(rr) management sub layer. In RR sub layer short msg service is supported by a control channel such as SDCCH or SACCH.

4 SMS MS-MSC protocol hierarchy (mobile origination)

5 Provides services to transfer SM-AL short message & corresponding delivery report Generate a reference number SMI (short message identifier) Types of transfer protocol data units (TPDUs) SMS-SUBMIT:- o conveys short msg, TP-DU(transfer msg user data from MS to SM-SC ) o Validity period buffered in SM-SC, if not delivered SMS-DELIVER:- o Conveys SM-SC to MS, TPDU includes service centre timestamp o Timestamp used to inform recipient MS time arrival, more send

6 SMS-STATUS-REPORT:- o Conveys report SM-SC to MS, report shows status sent msg o Msg not send then shows error, initiated by SMS-SUBMIT SMS-COMMAND:- o Conveys command MS to SM-SC. o Command can be query msg of submit, cancel or delete msg SMS-SUBMIT Parameters: MTI(m tune indicator): RD(reject duplicates): VPF(validity period format): SRR(status report request): UDHI(user data header indicator): RP(reply path):

7 Provides services to transfer TPDUs and delivery reports for SM-TL Generate SM-RL SMI for every short message. SM-RP provides interworking function betwn MS, SM-SC Types of RPDUs- RP-DATA- originating & terminating address RP-SM-MEMORY-AVAILABLE RP-ACK RP-ERROR

8 Provides services to support the SM-RL. MS has two SMC entity one handles MO & other MT. SM-CP consist of CP-DATA: MNSMS-ESTablish to deliver RPDU betwn MS & MSC CP-ACK: CP-ERROR: it provide cause of msg procedure errors. o MNSMS-ESTablish: -- To establish MM connection and transfer RPDU on that establish with SMC & SMR.

9 o MNSMS-DATA: -- Transfer RPDU on MM connection o MNSMS-Release: -- SMS is delivered completely, MM connection is released o MNSMS-ABORT: o MNSMS-ERROR:

10 Mobile-originated short messaging (part-i)

11 Fig: MM-connection establishment for mobile originated messaging Step 3(a)-: short msg service. Step 3(b)-: -- sent to VLR. -- delivered through SS7 n/w by using SS7 TCAP. Step 3(c)-: VLR checks, send ack MSC req Step 3(d)-: MSC forward the acceptance.

12 Step 4: It sets timer TC1 receive result before expires If expires transmission three times, not successful, the error reported. Step 5: TC1 timer reset, SMS-SUBMIT request is forwarded Step 6: TR2N expects to receive SMS-STETUS-REPORT. Step 7: VLR req subscriber-related information. It check req violates services or if restriction imposed

13 Mobile-originated short messaging (part 2) Step 8: VLR ack request positively or provide error Step 9: if VLR is +ve then msg is sent

14

15 Mobile-terminated short messaging (part 1)

16 Mobile-terminated short messaging (part 2)

17 Mobile-terminated short messaging (part 3) Step 21: MSC received SMS-STATUS-REPORT, the result is included in the msg MAP_FORWARD_SHORT_MESSAGE_ack Step 22: SMS GMSC invoke the procedure for delivery report. The SMS GMSC may take action for other failures/errors.

18 Scenario 1: T to T(john in singapore) Scenario 2: caller( hong cong) charged HC to Taiwan. & john charged T to S. Scenario 3: call delivery result in two international call is referred as tromboning.

19 ISC(international s/w centers) ISC offers internetworking fn bet national & international n/w. International call path composed: origination country, international n/w, destination cntry. ISCA+CC+MSISDN+NDC+SN PSTN s/w - ISC B - ISC C - GMSC D GMSC D queries HLR E to obtain MSRN HLR E queries VLR F MSRN return to GMSC D

20 GMSC D International call set up procedure ISC C 1.2 Singapore ISC B (Singapore) 6.1 (Taiwan) HLR E Taiwan VLR F PSTN s/w A MSC G

21 To avoid unnecessary trunk setups, an IAM msg should not travel across country boundaries before the destination is known. The solution utilized only existing msg with prefix MAP_. We implement RLC in first sol. RLC in visited system maintains a database containing's the record of international roamer.

22 ISC C Taiwan registration procedure (sol 1) 3 5 ISC B Singapore 4 singapore RLC HLR RLC MSC Taiwan 1 1 1

23 Call delivery (sol 1) & (sol 2) PSTN s/w A 1 ISC B (singapore) 2 1 RLC Jenny 4 3 VLR John 4 MSC

24 Solution 2: registration procedure (sol 2) ISC C (Taiwan) 3 4 ISC B (singapore) singapore HLR HLR 1 2 s/w D HLR MSC A 1 1

25 Solution 3: registration procedure (sol 3) ISC C (Taiwan) 2 4 ISC B (singapore) extractor 3 RLC HLR VLR s/w D MSC A 1 1 1

26 International roamer access code(irac) NDC1+CC+NDC2+SN Bidirectional signaling path betn GMSC & roamers HLR To fulfill the GMSC must: 1. Able to connect more than one SS7 signaling n/w 2. Be equipped with GTT that translate MSISDN into n/w indicator, point code & subsystem number 3. Be able to route an international MSRN into national n/w Advantage is VLR is not modified & no new n/w required Cost effective bcoz RLC is not required Limitation is many MSC may not required functionality

27 TMN (telecommunication management network): Operations system(os): overall TMN management Network element(ne): monitored or controlled Data communication n/w(dcn): OS, NE & TMN Mediation device(md): to route or pass info. Q-adaptor(QA): to connect non TMN entities. Workstation(WS): interacts the op/mntnce with OS.

28 Forwarding of event notification: Emit event notifications to OS. Event Report System management. Event forwarding Discriminator(EFD). Information logging: Info generate by May be stored in record file store Log Controls systems Mgmt Function Bulk data transfer between the OS & NE: Data transfer between OS NE uses the Common Mgmt Info Services CMISE controls of File Transfer Access & mgmt(ftam)

29 Tariff administrator: Billing: Accounting: Inter-PLMN(public land mobile n/w): Fixed n/w accounting: Customer accounting: Data collection: OS collect data from NEs thr data transfer control Record may save in log files Record may passed to OS & controlled by event reporting fn

30 OSF service provisin a b OSF c d OSF Billing accoun ting Cust admin e f OSF Tariff admi n Data collec tion tariff & charging admin G H i Tariff admi n Tarrif data Onlin e tarrif log cntrl log j event report log record event report Data gener n cntrl Real time event colln internal l telocommn event Aoc parameter Call recor ding fn event report gen cntrl Reco rd class Event forwa rding file transfer Record filestore Tariff admi n

31 Measurement attr modification in loc update: (a)modify measurement attr attlocation update MAP_UPDATE_LOCATION Location update operation in HLR VLR (b)modify measurement attr succlocation Update MAP_UPDATE_LOCATION_ACK

32 hlrfunction simplescanner hlrmeasurementfunction (HLR measurement object class containment) Measurement types: attlocationupdate: succlocationupdate: Measured n/w resource: Measurement functions: Measurement schedule: Granularity period: Scan report:

33 Number portability is a n/w fun that allows a subscriber to keep a unique telephone number. Three kinds of number portability Location portability: Service portability: NPA-NXX-XXXX Operator portability: Caller party pays in US Caller party pays in Taiwan & UK. Donor s/w: a telephone no. is assigned to a s/w. Recipient s/w: telephone no. is changed another s/w

34 Fixed Network Number Portability Call forwarding

35 Call drop-back

36 Query on release

37 All call Query

38 P represents the percentage of call termination. Ct represents the cost for switching & transmission elements. OFTEL estimates Ct to be $50/min for fixed n/w For mobile n/w 90/min Signaling cost $0.7/min Trunk drop-in query on release Cd is $18/min

39 Cost for switching & transmission elements. OFTEL also estimates the signaling cost For nonported call termination, no extra cost is incurred Query on release & call drop back required signaling interaction & call forwarding utilizes trunk/transmission resources of the donor s/w.

40 For number probability initial system setup is required, this setup includes cost System development Network management Line testing Operator services Billing information Exchanges overlay Maintenance & support.

41 For routing information Per line setup cost when moving a ported number Closing old acc & opening new acc Fixed n/w ported no. is estimated more cost than mobile no. estimation cost Cost for ported no. is not higher than non ported no. No. portability is treated as default function. Depend upon telecommunication policies, diff countries may have diff decision for cost recovery. The donor & recipient operators should bear their own cost.

42 It associated with two numbers: Directory no.(msisdn)- MDN Identification no.(imsi)- MIN The MIN/MDN is format NPA-NXX-XXXX. The first six digits if for identify home system of MS. The impact no. probability on MN is considered in three aspects: Location update: (IMSI or MIN) Mobile call origination: MSC equipped routing mechanism Mobile call termination:

43 Simplified GSM call termination procedure

44 Restrictions- 1. The GMSC must be in the call path for the provision of special feature & service, as well as for billing. 2. The originating switch does not have the capability to query the HLR d/b, which must be done by GMSC A tromboning effect may occur if both the calling party and the called MS are in the same city & GMSC is located in different city. SRF(signaling relay function)- provide routing information for ported numbers. IRN(Intermediate routing number)- consist of calling party number that indicates the recipient GMSC

45 Signaling relay approach 1

46 Signaling relay approach 2

47 Tromboning trunk setup in Signaling relay approach 2

48 All-call-query approach 1

49 All-call-query approach 2