GSM Network - from an Operators View SWINOG Meeting 10th of April 2003, Bern Swisscom Mobile AG, Engineering&Operations.

Präsentation zum Thema: "GSM Network - from an Operators View SWINOG Meeting 10th of April 2003, Bern Swisscom Mobile AG, Engineering&Operations."—  Präsentation transkript:

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2 GSM Network - from an Operators View SWINOG Meeting 10th of April 2003, Bern rudolf.schwarzenbach@swisscom.com Swisscom Mobile AG, Engineering&Operations

3 Thema: Menü Ansicht, Master, Folien-Master 2 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Agenda History Network Architecture Traffic Cases Transmission Process and Air Interface Cell Planning The Operators Challenge Network Evolution

4 Thema: Menü Ansicht, Master, Folien-Master 3 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj History Early 1800: Theory of Inductance (Faraday, Henry) 1906: Transmission of human voice over radio (Reginald Fessenden) 1935: Invention of frequency modulation (FM) 1947: Cellular Concept (D.H. Ring, Bell Labs) 1969: Standardization of the Nordic Mobile Telephone system 1981: First cellular system launched (NMT450; Ericsson) 1991: GSM standard launched 1993: Start of GSM rollout in Switzerland (Natel D) 2003: GSM networks have similar importance as fixed PSTNs

5 Thema: Menü Ansicht, Master, Folien-Master 4 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Fessendens Radio Tower (1906) vs. GSM Base Station (2003)

6 Thema: Menü Ansicht, Master, Folien-Master 5 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Network Architecture

7 Thema: Menü Ansicht, Master, Folien-Master 6 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj GSM / GPRS Network GMSC GGSN HLR EIR AUC SCF SMS- IWMSC SMS- IWMSC CNExternal Networks D Gd, Gp, Gn+ SGSN MSC E, G SMS- GMSC SMS- GMSC SGSN MSC Gb SMS-SC ISDN PSTN PSPDN CSPDN PDN: -Intranet -Extranet -Internet Iu ANUE BSC BTS Um SIM MT AbisA BSS Note: Not all interfaces are shown and named F Gf Gr Gn+ H

8 Thema: Menü Ansicht, Master, Folien-Master 7 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj HLR / AUC: Subscribers HLR AUC

9 Thema: Menü Ansicht, Master, Folien-Master 8 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj GMSC HLR EIR AUC SCF SMS- IWMSC SMS- IWMSC CNExternal Networks MSC SMS- GMSC SMS- GMSC MSC SMS-SC ISDN PSTN MSC/VLR, Core Network

10 Thema: Menü Ansicht, Master, Folien-Master 9 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Base Station System ANUE BSC BTS Um SIM MT Abis BSS GMSC HLR EIR AUC SCF SMS- IWMSC SMS- IWMSC CNExternal Networks MSC SMS- GMSC SMS- GMSC MSC SMS-SC ISDN PSTN

11 Thema: Menü Ansicht, Master, Folien-Master 10 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj GPRS in addition GMSC GGSN HLR EIR AUC SCF SMS- IWMSC SMS- IWMSC CNExternal Networks D Gd, Gp, Gn+ SGSN MSC E, G SMS- GMSC SMS- GMSC SGSN MSC Gb SMS-SC ISDN PSTN PSPDN CSPDN PDN: -Intranet -Extranet -Internet Iu ANUE BSC BTS Um SIM MT AbisA BSS Note: Not all interfaces are shown and named F Gf Gr Gn+ H

12 Thema: Menü Ansicht, Master, Folien-Master 11 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Good Coverage requires high number of Sites and Cells Area Coverage 83% Population Coverage 99,5%

13 Thema: Menü Ansicht, Master, Folien-Master 12 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Train Coverage (Intrain Repeater) Following coaches are or will be equipped: ICN 2000, IC2000, EW 4

14 Thema: Menü Ansicht, Master, Folien-Master 13 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj MS - Hardware (User Equipment) Mandatory Display of called number DTMF tones Indication of call progress PLMN indication / selection IMSI / IMEI Algorithms SMS handling Emergency calls Optional Keypad Key + Datacom interface... Additional Last numbers list Voice dialling...

15 Thema: Menü Ansicht, Master, Folien-Master 14 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Security Features (Authentication, Ciphering) Forbidden PLMN BCCH Information (Neighbor Frequencies) IMSI (International Mobile Subscriber Identity) LAI (Location Area Identity) PIN (Personal Identification Number) PUK Personal Phonebook SIM Service Table (Optional Services) SIM CARD SIM Card - The Subscriber

16 Thema: Menü Ansicht, Master, Folien-Master 15 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Traffic Cases

17 Thema: Menü Ansicht, Master, Folien-Master 16 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Key Terms Idle Mode Active Mode Detached Roaming Handover Registration (Location Update) Paging Idle Mode Active Mode Detached Roaming Handover Registration (Location Update) Paging

18 Thema: Menü Ansicht, Master, Folien-Master 17 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Location Updating 1-new LAI detected by MS 2-Authentication 3-LA update request to VLR 4-VLR stores LAI & sends LA update acknowledge to MS Keep the network informed on the actual location of each MS

19 Thema: Menü Ansicht, Master, Folien-Master 18 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Measurements sent to BSC Keep in touch with the network

20 Thema: Menü Ansicht, Master, Folien-Master 19 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Handover: Cells controlled by the same BSC 1-BSC activates call channel in new BTS 2-BSC informs MS on new freq via old BTS 3-MS sends handshake on new frequency 4-New BTS answers 5-MS sends HO complete via new BTS 6-Old BTS is released Do not drop the call when moving

21 Thema: Menü Ansicht, Master, Folien-Master 20 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj PSTN/ISDN BTS BTS BTS MSC HLR HLR VLR VLR BSC BSC PSTN/ISDN BTS BTS BTS MSC HLR HLR VLR VLR BSC BSC 1. Status of the mobile is stored in the HLR of the home network 2. If switched on in a foreign country it searches for an allowed GSM network 3. The foreign VLR asks for a copy of the subscription info in the HLR of the home network 4. The VLR registers the CH mobile as a visitor and updates the status of the mobile to idle The data is stored temporarely in the foreign VLR 5. In case of a PSTN call (CH) the foreign VLR checks the status of the CH mobile 6. If the mobile is switched on, the PSTN call is routed to the foreign GSM network International Call

22 Thema: Menü Ansicht, Master, Folien-Master 21 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Transmission Process and Air Interface

23 Thema: Menü Ansicht, Master, Folien-Master 22 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Transmission Process BSC SPP RRX Receiver Demodulator Receiver Demodulator 270 kBit/s, for 8TS Viterbi Equalizer Viterbi Equalizer De Ciphering De Ciphering De inter leaving De inter leaving Viterbi Decoder Viterbi Decoder Speech Decoder Speech Decoder A/D Speech Coding Speech Coding Segmen tation Segmen tation 160 Sample 20 ms 8 kHz,13 Bit 104 kbit/s Channel Coding Channel Coding 50 Hz, 260 Bits 13 kBit/s Inter leaving Inter leaving 50 Hz, 456 Bits 22,8 kBit/s Ciphering Burst Formatting Burst Formatting Modulator Transmitter Modulator Transmitter 33,8 kBit/s, for 1TS Mobile Station

24 Thema: Menü Ansicht, Master, Folien-Master 23 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj GSM Frequencies Example: 900MHz Band Separate bands for transmit and receive direction (duplex spacing) 124 carriers with 8 TDMA channels each Neighbor channel spacing is 200 kHz Time separation of transmission and reception signal allows for simpler RF front end in the mobile station (TDMA) Frequency resources must be shared between the national operators Duplex spacing

25 Thema: Menü Ansicht, Master, Folien-Master 24 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Multiple Access Methods FDMA TDMA W-CDMA Frequency Time Power Frequency Time Power Frequency Time Power GSM is a combination of FDMA and TDMA 1 user per freq several users per freq all users per freq

26 Thema: Menü Ansicht, Master, Folien-Master 25 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Packing Voice Calls into Time Slots Frequency Time Power Call 1 Call 3 Call 1 Call 2 Call 1 Frequency Time Power Call 1 Call 3 Call 1 Call 2 Frequency Time Power Call 1 Call 3 Call 1 Call 2 Carrier 1 Carrier 2 Carrier 3

27 Thema: Menü Ansicht, Master, Folien-Master 26 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Time Slot and Bit Rate Timeslot = window in time in which a portion of bits are transported over the air interface from the transmitter to the receiver The length of the time slot (577 s) allows to send approximately 160 bits, this is called a Burst 1 bit length is 3.7 s During a connection the burst is repeated 217x per second Based on the modulation type of GSM a gross bit rate of 271 kbps per carrier is achieved

28 Thema: Menü Ansicht, Master, Folien-Master 27 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj TDMA Frame Carrier with 8 Time Slots, 8 Physical Channels 012345 67 012345 67 Uplink Downlink 915 MHz 960 MHz 4.615 mS 0.577 mS

29 Thema: Menü Ansicht, Master, Folien-Master 28 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Close to BTS BTS TDMA-frame Far away from BTS The Time Alignment Problem TS6 TS7 TS6TS5 1 bit travels 1 km within 1 bit period (radio wave propagation) Far away user must send earlier to compensate for the higher time delay

30 Thema: Menü Ansicht, Master, Folien-Master 29 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Shadowing

31 Thema: Menü Ansicht, Master, Folien-Master 30 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Rayleigh Fading

32 Thema: Menü Ansicht, Master, Folien-Master 31 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Frequency selective Quality Degradation due to Rayleigh Fading

33 Thema: Menü Ansicht, Master, Folien-Master 32 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj The Antenna: A crucial Element for Radio Coverage and Performance

34 Thema: Menü Ansicht, Master, Folien-Master 33 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Example: Repeater Intrain Air Interface Radiating Cable

35 Thema: Menü Ansicht, Master, Folien-Master 34 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Example: Intrain Repeater Air Interface Antenna to/from intrain repeater

36 Thema: Menü Ansicht, Master, Folien-Master 35 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Cell Planning

37 Thema: Menü Ansicht, Master, Folien-Master 36 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj The Cellular Principle Why do we use cells? Traffic capacity Limited frequency resources (re-use) NIS electromagnetic radiation limitations User location

38 Thema: Menü Ansicht, Master, Folien-Master 37 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Cell Planning; Theoretical Cell Pattern Example: 4/12 = 4 three-sector sites supporting 12 cells

39 Thema: Menü Ansicht, Master, Folien-Master 38 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Cell Planning: Real Cell Boarders

40 Thema: Menü Ansicht, Master, Folien-Master 39 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj The Operators Challenge

41 Thema: Menü Ansicht, Master, Folien-Master 40 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj The Operators Challenge; some Issues Customer Needs Service Creation Billing Interoperability (e.g. International Roaming) Public Relations (e.g. NIS) Technical Operations

42 Thema: Menü Ansicht, Master, Folien-Master 41 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Traffic: Week- and Daytime, but also Event dependant

43 Thema: Menü Ansicht, Master, Folien-Master 42 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Hot Spots Load/Overload according to Workday Workday Sunday

44 Thema: Menü Ansicht, Master, Folien-Master 43 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Verify where the Traffic takes place

45 Thema: Menü Ansicht, Master, Folien-Master 44 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Managing the Mobility: Neighbor Relations

46 Thema: Menü Ansicht, Master, Folien-Master 45 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Operator Benchmarking: Focus on the relevant Issues

47 Thema: Menü Ansicht, Master, Folien-Master 46 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Example: Inbound Roaming

48 Thema: Menü Ansicht, Master, Folien-Master 47 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Building Permissions

49 Thema: Menü Ansicht, Master, Folien-Master 48 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Network Environment Radiation Measurements Calculation and preparation of NIS data for local authorities Negotiations with all involved parties

50 Thema: Menü Ansicht, Master, Folien-Master 49 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Network Evolution

51 Thema: Menü Ansicht, Master, Folien-Master 50 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Evolution towards 3G GMSC GGSN HLR EIR AUC SCF SMS- IWMSC SMS- IWMSC CNExternal Networks D Iu Gd, Gp, Gn+ SGSN MSC E, G SMS- GMSC SMS- GMSC SGSN MSC Gb SMS-SC ISDN PSTN PSPDN CSPDN PDN: -Intranet -Extranet -Internet Iu ANUE BSC BTS Um SIM MT AbisA BSS RNC BS Uu Iur USIM ME RNC BS Uu USIM ME Iub Cu RNS UTRAN Note: Not all interfaces are shown and named F Gf Gr Gn+ H

52 Thema: Menü Ansicht, Master, Folien-Master 51 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj 10 50 100 384 500 1000 2000 5000 GSM CS9.6 UMTS local Data rate (kbps) Voice HSCSD GPRS EDGE / EHSCSD EDGE / EGPRS UMTS wide area E-Mail data base access, info services telebanking, financial services electronis newspaper, images, sound teleshopping video telephony video conferencing Mobile Services and Data Rates

53 Thema: Menü Ansicht, Master, Folien-Master 52 Vorname, Name, Dateiname (Menü Ansicht, Kopf-und Fusszeile) tt. MMMM jjjj Thank you for your attention!