BSSbsc.docx

1、BSSbscDX 200 BSCDX 200 BSC General DescriptionTraining Document Copyright Nokia Telecommunications Oy 2018. All rights reserved.No part of this publication may be copied, distributed, transmitted, transcribed, stored in a retrieval system, or translated into any human or computer language without th

2、e prior written permission of Nokia Telecommunications Oy.The manufacturer has made every effort to ensure that the instructions contained in the documents are adequate and free of errors and omissions. The manufacturer will, if necessary, explain issues which may not be covered by the documents. Th

3、e manufacturers liability for any errors in the documents is limited to the correction of errors and the aforementioned advisory services.The documents have been prepared to be used by professional and properly trained personnel, and the customer assumes full responsibility when using them. The manu

4、facturer welcomes customer comments as part of the process of continual development and improvement of the documentation in the best way possible from the users viewpoint. Please submit your comments to the nearest Nokia sales representative.NOKIA and the arrows logo are registered trademarks of Nok

5、ia Corporation.No. of pages49/TTEditor/Translator31-Oct-97Miia SjgrenAuthor25-Sep-97Almut NaujeckApproved by25-Sep-97Stephan FlickPrevious issue(1.0) approved14-Feb-971. OBJECTIVES 2. BSC IN THE GSM NETWORK 3. BSC FUNCTIONS 3.1. Configuration and Management of the Radio Resources 3.2. Handover manag

6、ement 3.3. Frequency hopping management 3.3.1. No frequency hopping 3.3.2. Baseband hopping 3.3.3. Synthesized Frequency Hopping 3.4. Signalling between MSC and BSC 3.5. Signalling between BSC and BTS 3.6. Terrestrial Channel Management 3.7. Interfaces 3.8. Encryption management 3.9. Operation 3.10.

7、 Maintenance 3.11. Measurement and Observation 3.12. Support to Call Control 3.13. Extension Strategy 3.14. Configuration 4. CAPACITY OF THE BSC1E, BASIC AND EXTENSION CONFIGURATION 4.1. Capacity of the BSC1E, Basic configuration 4.2. Capacity of the BSC1E, Basic and Extension Configuration 4.3. Lay

8、-out of cartridges of DX 200 BSC1E 5. CAPACITY OF THE BSC2E, BASIC AND EXTENSION CONFIGURATION 5.1. Capacity of the BSC2E, Basic and Extension Configuration 6. BLOCK DIAGRAM OF THE BSC 7. FUNCTION OF THE FUNCTIONAL UNITS IN THE BSC 8. EXCHANGE TERMINAL, ET 8.1. Exchange Terminal, ET1E 8.1.1. General

9、 functions of the ET (ET1E, ET2E): 8.1.2. Special functions of the ET1E 8.1.3. ET1C, Exchange Terminal Cartridge 8.2. Exchange Terminal, ET2E 8.2.1. General functions of the ET (ET1E, ET2E): 8.2.2. Special functions of the ET2E 8.2.3. LED indicators 8.2.4. ET5C, Exchange Terminal Cartridge 9. GROUP

10、SWITCH, GSW 9.1. Plug-in Units in the Group Switch cartridge, SW1C 9.2. Switching operation in the GSW 10. GROUP SWITCH, GSWB 10.1. Plug-in Units in the Group Switch cartridge, SW1C 11. SUBMULTIPLEXER 11.1. SMUX units in the MCMU cartridge 11.2. Operation of the SMUX 12. CLOCK AND SYNCHRONISATION UN

11、IT, CLS 12.1. General functions of the CLS 12.2. Clock and Synchronisation Unit Cartridge, CLS 13. MARKER AND CELLULAR MANAGEMENT UNIT, MCMU 13.1. Plug-In Units in the MC1M cartridge 14. BSC SIGNALLING UNIT, BSCU 14.1. General functions of the BCSU 14.2. Plug-In Units in the MC1M cartridge 15. OPERA

12、TION AND MAINTENANCE UNIT 15.1. Plug-In Units in the OMU cartridge 16. WINCHESTER AND FLOPPY DRIVE UNITS 17. POWER SUPPLY SYSTEM IN THE BSC 17.1. DC / DC converters in the BSC 17.2. Power redundancy in the BSC 18. DX 200 BSC, MML 1. ObjectivesThis module describes the functions of the BSC, its capac

13、ity and configuration. Ideally after studying this material you should be able to:- Given a BSS network example design an Abis-Interface structure for it (BSS exercise)- Calculate the capacity required within the BSC to serve this example (BSS exercise)- Calculate the number of 2Mbit/s links in the

14、A- and Ater-Interfaces for this example network. (BSS exercise)2. BSC in the GSM NetworkBase Station Controller, BSC, is a part of the Base Station sub-system, BSS. It is responsible for the management of the radio network in the BSS.BSC is located between the MSC (TC) and the BTSs.Fig. 2.1 Base Sta

15、tion Controller in the GSM / DCS 1800 network3. BSC FunctionsConfiguration and Management of the Radio Resources- BCF, BTS and TRX management- channel allocation- channel release- radio link supervision (measurement handling)- power control (BTS and MS)BCCH / CCCH managementBroadcast Control Channel

16、/Common Control Channel- FCCH Frequency Correction Channel- SCH Synchronisation Channel- BCCH Broadcast Control Channel- RACH Random Access Channel- AGCH Access Grant Channel- PCH Paging ChannelTCH/SDCCH management- SDCCH Stand alone Dedicated Control Channel- SACCH Slow Associated Control Channel-

17、FACCH Fast Associated Control Channel- TCH/F Traffic Channel Full RateFig. 3.1 Radio channels management in the BSCHandover managementHandovers in GSM are based on the following parameters:- Signal quality (bad signal quality, up / down link)- Signal level (weak signal level, up / down link)- Interf

18、erence (TS disturbance, up / down link)- Power budget (max. TX power in BTS and MS)- Distance (distance 35 km)These values are measured by BTSs and MSs and the measurement data is stored in the BSC. The BSC is responsible for making the handover decisions, which can be following:Intra-BSC intra-cell

19、- between two time slots in the same carrier or two carrier in the same BTSIntra-BSC inter-cell- between two carriers in different BTSsInter-BSC- between two BTSs in different BSCsFig. 3.2 Handover management in the BSCFrequency hopping managementFrequency hopping improves BTS-MS link quality. There

20、 are three different possibilities for Frequency hopping: No frequency hopping, Baseband frequency and Synthesizer hopping.No frequency hopping- In the BTS, BBM-Part of TRX 1 is permanently connected to RF-Part of TRX 1. BBM-Part of TRX 2 is permanently connected to RF-Part of TRX 2. The frequencies

21、 of TRXs are fixed.Fig. 3.3 BTS without frequency hoppingBaseband hoppingThe digital (baseband) and analogue (RF) parts of a TRX are separated from each other.A Bus is used to connect and cross-switch the baseband and radio parts of the transceivers.Baseband hopping sequence can be:- Cyclic: TS x of

22、 TDMA frame n from BBM-Part 1 is connected to RF Part 1. TS x of TDMA frame n+1 from BBM-Part 1 is connected to RF Part 2 end so on. - Pseudo-random: sequence is according to an algorithm in GSM specifications.Fig. 3.4 Baseband hopping management in the BSSSynthesized Frequency HoppingSynthesized fr

23、equency hopping enables each other TRX to change the frequency of the RF-Part on successive Time-slots.Hopping sequence can be:- Cyclic: BBM-Part of TRX 1 is permanently connected to RF Part of TRX 1. The frequency of the RF-Part will change between a number of frequencies.- Pseudo-random: sequence

24、is according to an algorithm in GSM specifications.Fig. 3.5 Synthesized hopping management in the BSSSignalling between MSC and BSC Common channel signalling (CCS7) is used between MSC and BSC. The AS7-U PIU in the BCSU cartridge of the BSC provides Message Transfer Part functions; MTP (in MSC the A

25、S7-U PIU in BSU cartridge is used). The protocol MTP routes the signalling message according to the destination point code (OSI layer 1, 2 and lower part of layer 3). On top of the MTP there is a Signalling Connection Control Part, SCCP to direct the message to the right user part.The user part prot

26、ocol which is used between MSC and BSS is “BSS Application part, BSSAP”. BSSAP is divided into two sub-layers: Direct Transfer Application Part, DTAP: which is used for direct communication between the MSC and the MS BSS Management Application Part, BSSMAP: which is used for communication between MS

27、C and the BSC.Fig. 3.6 CCS7 management in the BSCSignalling between BSC and BTSLAPD signalling is used between the BSC and the BTS: TRXSIG: is used for carrying signalling information between BSC and BTS as well as between BSC and MS BCFSIG is used for carrying O&M information between BSC and BCFA u

28、nit in BSFig. 3.7 LAPD link management in the BSCTerrestrial Channel ManagementChannel management in A interface:- managing the Traffic channels and the CCS7 signalling channelsChannel management in the Abis interfaces:- managing the Traffic and LAPD signalling channelsFig. 3.8 Terrestrial channel m

29、anagement in the BSCInterfacesA-interface to the MSC:- Ater interface to TCSM2EAbis interface to the BTS direction:X.25 connection to the OMC:- PAD interface to the OMC using OSI stack (PAD: package assembly disassembly)- file transfer for loading program and data for the BSC/BS- file transfer for m

30、easurements and observationsFig. 3.9 Interfaces in the BSSEncryption management- store the encryption parameters (Kc)- forwards the encryption parameters to the BTS (Kc)OperationOne local MMI terminal for - BSC parameters modification handling- BTS parameters modification handlingOne local printer f

31、or- alarm print outs- parameter print outsMaintenance- BSC reconfiguration, fault localisation, SW replacement- BTS reconfiguration, SW handling, alarm handlingMeasurement and Observation- traffic measurements- signalling event observations- observation of specific mobile (tracing)Support to Call Control- queuing / priority- circuit switching- Short Message Service- DTMF control signals are transparentExtension Strategy- cell splitting or expansion- adding / removing BTS(s) and equipment- adding / removing channel(