Huawei GSM Principles

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Huawei GSM Principles

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Huawei GSM Principles

  1. 1. www.huawei.com Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. GSM Principles
  2. 2. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page2 Objectives  Upon completion of this course, you will be able to:  Grasp basic idea of GSM system such as frequency spectrum, frequency reuse etc.  Grasp the structure of the GSM system and the protocol used.  Grasp certain numbers that refer to BSS  Grasp the 4 kinds of channel combination and understand the idea of multi-frame.  Know some radio techniques  Get the idea of EDGE
  3. 3. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page3 References  BSS Feature Description  BSS Signaling Analysis Manual  BSC Technical Manual
  4. 4. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page4 Contents 1. GSM System Overview 2. GSM Network Structure 3. Service Area and Number Planning 4. Channels on the Wireless Interface 5. Radio Techniques 6. GPRS & EDGE Introduction
  5. 5. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page5 Contents 1. GSM System Overview 2. GSM Network Structure 3. Service Area and Number Planning 4. Channels on the Wireless Interface 5. Radio Techniques 6. GPRS & EDGE Introduction
  6. 6. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page6 GSM system overview  The GSM system is a frequency- and time-division cellular system, each physical channel is characterized by a carrier frequency and a time slot number  Cellular systems are designed to operate with groups of low-power radios spread out over the geographical service area. Each group of radios serve MSs presently located near them. The area served by each group of radios is called a CELL  Uplink and downlink signals for one user are assigned different frequencies, this kind of technique is called Frequency Division Duplex (FDD)  Data for different users is conveyed in time intervals called slots , several slots make up a frame. This kind of technique is called Time Division Multiple Access (TDMA)
  7. 7. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page7 GSM Development Standard Protocol for GSM take effect System was named as Global System for Mobile Communication GSM system began to provide service in Europe(2G) Provide services for the whole world Micro Cell Technique is used in GSM system 1989 1991 1992 1994 1996
  8. 8. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page8 Cell Technique  Macro Cell and Micro Cell  A certain radio coverage area formed by a set of transceivers that connected to a set of antennas is called a CELL.  Macro Cell  In the beginning , High-Power BTSs are adopted to provide services. The BTS covers a wider area , but its frequency utilization is not efficient. So , it can only provide a few channels for subscribers.  Micro Cell  Later the Low-Power BTS joins the system for getting a better service area with high capacity . At the same time it adopts the frequency reuse technique to improve the efficiency of the frequency utilization and also the whole capacity of the network.
  9. 9. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page9 Multiple Access Technique  Multiple Access Technique allows many subscribers to use the same communication medium.  There are three kinds of basic Multiple Access Technique : FDMA , TDMA and CDMA.  GSM system adopt FDD-TDMA (FDMA and TDMA together).
  10. 10. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page10 FDMA  FDMA uses different frequency channels to accomplish communication.  The whole frequency spectrum available is divided into many individual channels (for transmitting and receiving), every channel can support the traffic for one subscriber or some control information. Frequency Time
  11. 11. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page11 TDMA  TDMA accomplishes the communication in different timeslot.  A carrier is divided into channels based on time. Different signals occupy different timeslots in certain sequence , that is , many signals are transmitted on the same frequency in different time. Time Frequency
  12. 12. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page12 CDMA  CDMA accomplishes the communication in different code sequences.  Special coding is adopted before transmission, then different information will lose nothing after being mixed and transmitted together on the same frequency and at the same time. Time Frequency
  13. 13. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page13 GSM 900 Duplex Separation: 45MHz Channel Bandwidth: 200KHz The Frequency Spectrum Uplink 890 915 935 960MHz Downlink
  14. 14. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page14 Duplex Separation: 95MHz Channel Bandwidth: 200KHz Base Station Receive 1710 1785 1805 1880MHz Base Station Transmit DCS 1800 The Frequency Spectrum
  15. 15. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page15 The Frequency Spectrum Frequency Spectrum Range (MHz) Uplink Frequency Frequency Point Available Downlink Frequency GSM 450 450.4~457. 6 460.4~467. 6 Fu(n)=450.6+0.2(n- 259) 259<=n<=293 Fd(n)=Fu(n)+1 0 GSM 480 478.8~486 488.8~496 Fu(n)=479+0.2(n-306) 306<=n<=340 Fd(n)=Fu(n)+1 0 GSM 850 824~849 869~894 Fu(n)=824.2+0.2(n- 128) 128<=n<=251 Fd(n)=Fu(n)+4 5 E-GSM 900 880~915 925~960 Fu(n)=890+0.2n Fu(n)=890+0.2(n-1024) 0<=n<=124 975<=n<=102 3 Fd(n)=Fu(n)+4 5 R-GSM 900 876~915 921~960 Fu(n)=890+0.2n Fu(n)=890+0.2(n-1024) 0<=n<=124 955<=n<=102 3 Fd(n)=Fu(n)+4 5 PCS 1900 1850~1910 1930~1990 Fu(n)=1850.2+0.2(n- 512) 512<=n<=810 Fd(n)=Fu(n)+8 0
  16. 16. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page16 Frequency Reuse  The frequency resource of mobile system is very limited.  The different Subscribers can use the same frequency in different places.  The quality of communication must be ensured.
  17. 17. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page17 Frequency Reuse 7(Site)X 1(Cell) reuse 2 1 2 3 4 5 6 7
  18. 18. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page18 4 site X 3 cells reuse 1 8 9 2 10 4 6 5 3 7 11 12 R Frequency Reuse
  19. 19. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page19 Cell Types Omni 1 120 degree 1 2 3 Omni-directional Cell 120 Degree Cell
  20. 20. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page20 Contents 1. GSM System Overview 2. GSM Network Structure 3. Service Area and Number Planning 4. Channels on the Wireless Interface 5. Radio Techniques 6. GPRS & EDGE Introduction
  21. 21. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page21 GSM-GPRS Network Component GSM /GPRS BSS BTS BSC BTS BSC PCU SS7 SMS system PSTN ISDN Internet, Intranet MSC/VLR GMSC HLR/AUC SGSN CG BG GGSN GPRS Backbone Other PLMN MS MS OMC
  22. 22. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page22 Interface Between Different Entities GSM /GPRS BSS BTS BSC BTS BSC PCU SS7 SMS system PSTN ISDN Internet, Intranet MSC/VLR GMSC HLR/AUC SGSN CG BG GGSN GPRS backbone Other PLMN A Gb Gi Gp C/D/Gs Gr/Gs/Gd/Ge Gc Ga Abis Um MS MS OMC
  23. 23. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page23 Mobile Station—MS International Mobile Equipment Identity (IMEI) – Mobile Equipment MS=ME+SIM International Mobile Subscriber Identity (IMSI) – Subscriber Identity Module
  24. 24. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page24 Subscriber Identity Module – SIM  International Mobile Subscriber Identity (IMSI)  Temporary Mobile Subscriber Identity (TMSI)  Location Area Identity (LAI)  Subscriber Authentication Key (Ki) SIM
  25. 25. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page25 BTS BSC TC/SM BSS MSC Base Station Subsystem – BSS  The Base Station Controller – BSC  The Base Transceiver Station – BTS  The Trans-coder – TC and Sub multiplexer (SM)
  26. 26. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page26 BTS BSC TC/SM BSS MSC Packet Control Unit-----PCU  Packet data switching  Bridge between SGSN and BSC  Provide Pb and Gb interface GPRS Backbone PCU SGSN
  27. 27. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page27 Mobile-service Switching Center – MSC Home Location Register – HLR Visitor Location Register – VLR Equipment Identity Register – EIR Authentication Center – AUC Echo Cancellor – EC AUC HLR MSC/VLR PSTN NSS EIROMC BSS EC The Network Switching System
  28. 28. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page28 Mobile-service Switching Center – MSC  Call Processing  Operations and Maintenance Support  Interface management  Inter-network & Inter-working  Billing
  29. 29. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page29 Home Location Register – HLR  Subscriber ID (IMSI and MSISDN)  Current subscriber VLR (current location)  Supplementary service information  Subscriber status (registered/deregistered)  Authentication key and AuC functionality
  30. 30. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page30 Visitor Location Register – VLR  Mobile Status (IMSI attached / detached / busy / idle etc.)  Location Area Identity(LAI)  Temporary Mobile Subscriber Identity(TMSI)  Allocating the Roaming Number
  31. 31. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page31 IMEI is Checked In White List IMEI is Checked in Black/Grey List If NOT found EIR focus on the equipment , not the subscriber! Equipment Identity Register – EIR  White List  Black List  Grey List
  32. 32. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page32 OMC Functional Architecture OS MMI DB Event/Alarm Management Security Management Configuration Management Performance Management Fault Management
  33. 33. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page33 Contents 1. GSM System Overview 2. GSM Network Structure 3. Service Area and Number Planning 4. Channels on the Wireless Interface 5. Radio Techniques 6. GPRS & EDGE Introduction
  34. 34. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page34 Service Area PLMN service area ...... Service Area MSC service area... Location area... cell PLMN service area PLMN service area MSC service area... Location area... cell
  35. 35. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page35 LAI Location Area Identification The LAI is the international code for a location area. MCC: Mobile Country Code,It consists of 3 digits . For example: The MCC of China is "460" MNC: Mobile Network Code,It consists of 2 digits . For example: The MNC of China Mobile is "00" LAC: Location Area Code,It is a two bytes hex code. The value 0000 and FFFF is invalid. For example: 460-00-0011 MCC MNC LAC
  36. 36. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page36 CGI The CGI is a unique international identification for a cell The format is LAI+CI LAI: Location Area Identification CI: Cell Identity. This code uses two bytes hex code to identify the cells within an LAI. For example : 460-00-0011-0001 CGI: Cell Global Identification
  37. 37. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page37 BSIC NCC: PLMN network color code. It comprises 3 bit. It allows various neighboring PLMNs to be distinguished. BCC: BTS color code. It comprises 3 bit, used to distinguish different cells assigned the same frequency! NCC BCC BSIC BSIC(Base Station Identification Color Code)
  38. 38. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page38 CC: Country Code. For example: The CC of China is "86". NDC: National Destination Code. For example: The NDC of China Telecom is 139, 138, 137, 136, 135. SN: Subscriber Number. Format:H0 H1 H2 H3 ABCD Example: 86-139-0666-1234 MSISDN CC NDC SN National (significant) Mobile number Mobile station international ISDN number
  39. 39. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page39 MCC: Mobile Country Code,It consists of 3 digits . For example: The MCC of China is "460"。 MNC: Mobile Network Code,It consists of 2 digits . For example: The MNC of China Telecom is "00"。 MSIN: Mobile Subscriber Identification Number. H1H2H3 S ABCDEF For example: 666-9777001 NMSI: National Mobile Subscriber Identification,MNC and MSIN form it together. For Example of IMSI : 460-00-666-9777001 Not more than 15 digits 3 digits 2 digits IMSI MCC MNC MSIN NMSI IMSI
  40. 40. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page40 TMSI  The TMSI is assigned only after successful subscriber authentication.  The VLR controls the allocation of new TMSI numbers and notifies them to the HLR.  TMSI is used to ensure that the identity of the mobile subscriber on the air interface is kept secret.  The TMSI consists of 4 bytes( 8 HEX numbers) and determined by the operator. TMSI: Temporary Mobile Subscriber Identification)
  41. 41. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page41 IMEI TAC FAC SNR SP IMEI IMEI: International Mobile Station Equipment Identification TAC: Type approval code, 6 bit, determined by the type approval center FAC: Final assembly code, 2 bit, It is determined by the manufacturer. SNR: Serial number, 6 bits, It is issued by the manufacturer of the MS. SP: 1 bit , Not used. Check the IMEI in your MS : *#06#
  42. 42. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page42 Contents 1. GSM System Overview 2. GSM Network Structure 3. Service Area and Number Planning 4. Channels on the Wireless Interface 5. Radio Techniques 6. GPRS & EDGE Introduction
  43. 43. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page43 2 30 16 74 52 3 The physical channel is the medium over which the information is carried: 200KHz and 0.577ms 0 1 TDMA FRAME Timeslot The information carried in one time slot is called a “burst” Physical Channel and Logical Channel The logical channel consists of the information carried over the physical channels TDMA FRAME
  44. 44. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page44 Two types of Logical Channel Traffic Channel (TCH) : Transmits traffic information, include data and speech. Control Channel (CCH) : Or Signaling Channel, transmits all kinds of control information.
  45. 45. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page45 Traffic Channel (TCH) TCH Traffic Channels Speech TCH/FS Data TCH/HS TCH/9.6 TCH/2.4 TCH/4.8 TCH Traffic Channel TCH/FS Full rate Speech Channel TCH/HS Half rate Speech Channel TCH/9.6 Data Channel 9.6kb/s TCH/4.8 Data Channel 4.8kb/s TCH/2.4 Data Channel 2.4Kb/s
  46. 46. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page46 FCCHSCH CCH (Control Channels) DCCH SDCCH BCH BCCH Synch. CH. ACCH SACCHFACCH CCCH RACH CBCH PCH/AGCH Broadcast Control Channel – BCCH Common Control Channel – CCCH Dedicated Control Channel – DCCH Associated Control Channel – ACCH Control Channel (CCH)
  47. 47. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page47 CCH BCH BCCH Synch. Channels SCH FCCH The information carried on the BCCH is monitored by the MS periodically when it is in idle mode BCCH: Broadcast Control Channel FCCH: Frequency Correction Channel SCH: Synchronization Channel Broadcast Control Channel – BCCH
  48. 48. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page48 CCH CCCH RACH uplink CBCH downlink PCH/AGCH downlink The CCCH is responsible for transferring control information between all mobiles and the network. RACH: Random Access Channel PCH: Paging Channel AGCH: Access Granted Channel CBCH: Cell Broadcast Channel Common Control Channel – CCCH
  49. 49. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page49 CCH DCCH SDCCH FACCH SACCH DCCH is assigned to a single wireless connection for measurement and handover purpose. SDCCH: Stand-alone Dedicated Control Channel ACCH: Associated Control Channel SACCH: Slow Associated Control Channel FACCH: Fast Associated Control Channel ACCH Dedicated Control Channel – DCCH
  50. 50. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page50 RACH CCCH CCH SDCCH SACCH FACCH TCH/F TCH/H DCCH TCH DCH Uplink Logical channel
  51. 51. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page51 FCCH SCH BCCH PCH AGCH BCCH CCCH CCH SDCCH SACCH FACCH TCH/F TCH/H DCCH TCH DCH Downlink Logical channel
  52. 52. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page52 Allocate signaling channel FCCH SCH BCCH PCH RACH AGCH SDCCH SDCCH TCH FACCH Power-off Idle mode Dedicated mode Idle mode How to use these channels? Search for frequency correction burst Search for synchronous burst Extract system information Monitor paging message Send access burst Set up the call Allocate voice channel Conversation Release the call
  53. 53. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page53 Packet logic channel  Packet data channel (PDCH)  Comprising packet service channel and packet control channel  Packet service channel (PDTCH)  Combined into the single-directional service channel  Packet control channel  Broadcast control channel: PBCCH  Public control channel: PPCH, PRACH, PAGCH  Private control channel: PACCH, PTCCH TCH BCCH SACCH CCCH TCH
  54. 54. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page54 GSM Logical Channel Combination  Main BCCH combination – FCCH + SCH + BCCH + CCCH  SDCCH combination – SDCCH/8 + SACCH/8  Combined BCCH – BCCH + CCCH +SDCCH/4 + SACCH/4  TCH/FR combination – TCH/F + FACCH/F + SACCH/F  TCH/HR combination – TCH/H + FACCH/H + SACCH/H
  55. 55. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page55 Combination of packet logic channel  Packet logic channels (PDCH) can be combined via the following three modes  Mode 1: PBCCH+PCCCH+PDTCH+PACCH+PTCCH;  Mode 2: PCCCH+PDTCH+PACCH+PTCCH;  Mode 3: PDTCH+PACCH+PTCCH  In case of small GPRS traffic, GPRS and circuit services use the same BCCH and CCCH in the cell. In this case, only combination mode 3 is needed in the cell  With the increase of traffic, the packet public channel should be configured in the cell. Channel combination mode 1 and mode 2 should be adopted
  56. 56. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page56 TDMA Frames 0 1 0 1 2 43 46 47 48 5049 51 – Frame Multi-frames 0 1 10 CONTROL CHANNELS 2 3 4 5 6 7 2 3 5 764 GSM Multi-frames
  57. 57. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page57 GSM Multi-frames TDMA Frames 0 1 0 1 2 43 21 22 23 2524 26 – Frame Multi-frames 0 1 10 TRAFFIC CHANNELS 2 3 4 5 6 7 2 3 5 764
  58. 58. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page58 Contents 1. GSM System Overview 2. GSM Network Structure 3. Service Area and Number Planning 4. Channels on the Wireless Interface 5. Radio Techniques 6. GPRS & EDGE Introduction
  59. 59. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page59 Power Control Saves battery power Reduces co-channel and adjacent channel interference 8W 0.8W 5W Both Uplink and Downlink power settings can be controlled independently and individually. BCCH ------- Does not attend Power control
  60. 60. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page60 DTX and VAD Voice Activity Detection – VAD Discontinuous Transmission – DTX Battery Saving Interference reduction
  61. 61. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page61 Timing Advance (TA) Transmission delay t Transmission delay t TA The mobile phone should send the signal in advance!
  62. 62. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page62 Multi-path Fading  Diversity  Frequency Hopping Time Dispersion
  63. 63. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page63 Diversity – What’s Diversity?  Receive diversity provides an effective technique for both overcoming the impact of fading across the radio channel and increasing the received signal to interference ratio.  The former is achieved by ensuring “uncorrelated” (i.e. low enough correlated) fading between antenna branches i.e. not all antennas experience fades at the same time.
  64. 64. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page64 Kinds of Diversity  Time diversity Coding, interleaving  Frequency diversity Frequency hopping  Space diversity Multiple antennas  Polarization diversity Dual-polarized antennas  Multi-path diversity Equalizer t f
  65. 65. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page65 Frequency Hopping Frequency f 0 Frame f 1 f 2 f 3 f 4 Time
  66. 66. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page66 Contents 1. GSM System Overview 2. GSM Network Structure 3. Service Area and Number Planning 4. Channels on the Wireless Interface 5. Radio Techniques 6. GPRS & EDGE Introduction
  67. 67. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page67 57.6 kbps 115 kbps 384kbps 2Mbps GSM HSCSD GPRS EDGE IMT-2000 9.6 kbps 2G 2.5G 3G GSM Development Evolution
  68. 68. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page68 Data rate of EDGE and GPRS 8PSKGMSK 9.0 13.4 15.6 21.4 8.8 11.2 14.8 17.6 22.4 29.6 44.8 54.4 59.2 0.0 10.0 20.0 30.0 40.0 50.0 60.0 CS-1 CS-2 CS-3 CS-4 MCS-1 MCS-2 MCS-3 MCS-4 MCS-5 MCS-6 MCS-7 MCS-8 MCS-9 Kbps GPRS EGPRS
  69. 69. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page69 Huawei EDGE Test Result Downlink, 4 TS, MCS-9:
  70. 70. Copyright © 2010 Huawei Technologies Co., Ltd. All rights reserved. Page70 Summary  The basic idea of GSM  The frequency spectrum used in GSM  The structure of GSM  Certain service area and numbers  Some radio techniques used in GSM  Evolution of GSM
  71. 71. Thank you www.huawei.com

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