Luận văn Mạng không dây băng thông rộng Wimax - Các vấn đề về công nghệ và triển khai ứng dụng

Bé gi¸o dôc vµ ®µo t¹o Tr−êng ®¹i häc b¸ch khoa hµ néi ------------------------------------- LuËn v¨n th¹c sÜ khoa häc M¹ng kh«ng d©y b¨ng th«ng réng WiMAX: C¸c vÊn ®Ò vÒ c«ng nghÖ vµ triÓn khai øng dông Chuyªn ngµnh : xö lý th«ng tin vµ truyÒn th«ng NguyÔn Hång Hµ Ng−êi h−íng dÉn khoa häc: Gs- ts. NguyÔn Thóc H¶i Hµ néi 2006 -2- LuËn v¨n tèt nghiÖp cao häc chuyªn ngµnh Xö lý Th«ng tin vµ TruyÒn th«ng niªn kho¸ 2004 - 2006 Môc lôc Môc lôc........................................................................................................ 2 C¸c thuËt ng÷ viÕt t¾t ................................................................................. 6 Danh môc h×nh........................................................................................... 8 Danh môc b¶ng .......................................................................................... 9 PhÇn më ®Çu............................................................................................ 10 Ch−¬ng I: Kh¸i qu¸t vÒ m¹ng côc bé kh«ng d©y..................................... 13 1.1 Më ®Çu ....................................................................................................13 1.2 KiÕn tróc m¹ng........................................................................................14 1.2.1 M« h×nh tæ chøc vµ nguyªn lý ho¹t ®éng: ........................................15 1.2.2 Mét sè tiªu chuÈn kü thuËt tiÓu biÓu cho WLAN .............................16 1.2.2.1 IEEE 802.11 ..............................................................................16 1.2.2.2 IEEE 802.11b ............................................................................16 1.2.2.3 IEEE 802.11a ............................................................................17 1.2.2.4 IEEE 802.11g ............................................................................17 1.2.3 C¸c kü thuËt ®iÒu chÕ .......................................................................17 1.2.3.1 Kü thuËt ®iÒu chÕ tr¶i phæ (Spread Spetrum Technique)...........19 1.2.3.2 Kü thuËt ®iÒu chÕ ph©n chia theo tÇn sè trùc giao OFDM........23 1.2.4 KÕt nèi .............................................................................................24 1.2.5 NhËn thùc........................................................................................25 1.2.6 Qu¶n lý chÊt l−îng dÞch vô .............................................................26 1.2.7 B¶o mËt ...........................................................................................26 1.3 C¸c dÞch vô m¹ng ....................................................................................27 1.3.1 Nhãm sö dông cho m¹ng dïng riªng................................................27 1.3.1.1 ThiÕt lËp m¹ng côc bé ...............................................................27 1.3.1.2 Sö dông cho c¸ nh©n..................................................................27 1.3.2 Nhãm sö dông cho phôc vô ë c¸c ®iÓm c«ng céng (§iÓm nãng). ...27 1.3.2.1 DÞch vô truy nhËp Internet.........................................................28 1.3.2.2 øng dông ®a ph−¬ng tiÖn ..........................................................28 1.3.2.3 DÞch vô th«ng tin.......................................................................28 1.3.3 Nhãm sö dông cho phñ sãng thÞ trÊn vµ thµnh phè nhá ..................28 1.4 KÕt luËn : .................................................................................................29 Ch−¬ng II: Giíi thiÖu m¹ng kh«ng d©y b¨ng th«ng réng WiMAX ....... 30 2.1 Më ®Çu ....................................................................................................30 2.2. KiÕn tróc m¹ng kh«ng d©y b¨ng th«ng réng WiMAX...........................31 2.2.1 Môc tiªu cña c«ng nghÖ WiMAX ......................................................32 2.2.2 C¬ chÕ ho¹t ®éng cña WiMAX .........................................................34 2.2.3 M« h×nh øng dông WiMAX ...............................................................37 2.2.3.1 M« h×nh øng dông cè ®Þnh (Fixed WiMAX) ............................37 2.2.3.2 M« h×nh øng dông WiMAX di ®éng.........................................38 2.2.4 C¸c chuÈn cña WiMAX ....................................................................38 2.2.4.1 Tiªu chuÈn 802.16- 2004...........................................................38 -3- LuËn v¨n tèt nghiÖp cao häc chuyªn ngµnh Xö lý Th«ng tin vµ TruyÒn th«ng niªn kho¸ 2004 - 2006 2.2.4.2 Tiªu chuÈn 802.16e ...................................................................39 2.2.5 B¨ng tÇn dµnh cho WiMAX .............................................................39 2.2.5.1 B¨ng tÇn kh«ng cÊp phÐp ..........................................................40 2.2.5.2 B¨ng tÇn ®−îc cÊp phÐp.............................................................40 2.2.6 Ph−¬ng thøc ®iÒu chÕ:.....................................................................43 2.2.6.1 Ph−¬ng thøc OFDM ..................................................................43 2.2.6.2 Ph−¬ng thøc OFDMA ...............................................................44 2.2.7 Qu¶n lý chÊt l−îng dÞch vô .............................................................45 2.2.8 B¶o mËt ...........................................................................................45 2.3 C¸c dÞch vô vµ øng dông cña m¹ng WiMAX..........................................45 2.3.1 M¹ng riªng .......................................................................................46 2.3.1.1 C¸c nhµ cung cÊp dÞch vô kh«ng d©y Backhaul ........................46 2.3.1.2 C¸c m¹ng Ng©n hµng ................................................................47 2.3.1.3 M¹ng Gi¸o dôc..........................................................................48 2.3.1.4 An toµn c«ng céng ....................................................................49 2.3.1.5 Liªn l¹c ë ngoµi kh¬i.................................................................50 2.3.1.6 GhÐp nèi c¸c tr−êng ®¹i häc, cao ®¼ng .....................................52 2.3.1.7 X©y dùng sù liªn l¹c t¹m thêi....................................................52 2.3.1.8 C¸c c«ng viªn gi¶i trÝ ................................................................53 2.3.2 M¹ng c«ng céng ...............................................................................53 2.3.2.1 M¹ng truy nhËp nhµ cung cÊp dÞch vô kh«ng d©y ....................54 2.3.2.2 KÕt nèi n«ng th«n......................................................................55 2.4 So s¸nh gi÷a c«ng nghÖ WiMAX vµ Wi-Fi.............................................55 2.5 KÕt luËn ...................................................................................................57 Ch−¬ng III. Tiªu chuÈn IEEE 802.16 ...................................................... 58 3.1 Më ®Çu ....................................................................................................58 3.2. Sù ph¸t triÓn cña tiªu chuÈn 802.16 .......................................................59 3.2.1 Tiªu chuÈn 802.16-2001 ..................................................................59 3.2.2 Tiªu chuÈn 802.16c-2002.................................................................60 3.2.3 Tiªu chuÈn 802.16a-2003 ................................................................60 3.2.4 Tiªu chuÈn 802.16- 2004 .................................................................61 3.2.5 Tiªu chuÈn 802.16e vµ ph¹m vi më réng cña nã . ...........................61 3.3 C¸c ph©n líp giao thøc trong ph¹m vi tiªu chuÈn IEEE 802.16 .............61 3.4 Líp vËt lý (PHY).....................................................................................63 3.4.1 C¸c hÖ thèng d¶i tÇn sè 10-66 GHz .................................................63 3.4.2 C¸c hÖ thèng d¶i tÇn sè 2-11 GHz ...................................................64 3.4.3 Qu¸ tr×nh kiÓm so¸t lçi.....................................................................65 3.4.3.1 Ph−¬ng ph¸p hiÖu chØnh lçi tiÕp tíi...........................................65 3.4.3.2 Ph−¬ng ph¸p yªu cÇu t¸i truyÒn t¶i tù ®éng ..............................66 3.4.4 Qu¸ tr×nh ®Þnh khung (Framing)......................................................66 3.4.4.1 Khung phô ®−êng xuèng...........................................................66 3.4.4.2 Khung phô ®−êng lªn. ...............................................................70 3.4.5 Ph©n líp phô héi tô truyÒn t¶i (TC).................................................71 3.5 Ph©n líp kiÓm so¸t truy nhËp m«i tr−êng truyÒn th«ng (MAC) .............72 3.5.1 Sù ®Þnh h−íng kÕt nèi . .....................................................................72 -4- LuËn v¨n tèt nghiÖp cao häc chuyªn ngµnh Xö lý Th«ng tin vµ TruyÒn th«ng niªn kho¸ 2004 - 2006 3.5.2 D÷ liÖu MAC PDU ...........................................................................73 3.5.2.1 M« t¶ PDU ................................................................................73 3.5.2.2 CÊu tróc cña MAC PDU............................................................74 3.5.3 C¸c ph©n líp phô .............................................................................76 3.5.3.1 Ph©n líp phô héi tô (CS) ...........................................................76 3.5.3.2 Ph©n líp phô cã phÇn chung víi ph©n líp MAC (MAC CPS) ..77 3.5.3.3 Ph©n líp phô thuéc tÝnh riªng. ..................................................78 3.5.4 KiÓm so¸t liªn kÕt sãng v« tuyÕn ......................................................78 3.5.5 Khëi t¹o vµ truy nhËp m¹ng.............................................................79 3.5.5.1 QuÐt (Scanning) vµ ®ång bé ho¸ ®èi víi ®−êng xuèng .............80 3.5.5.2 C¸c tham sè truyÒn t¶i thu nhËn................................................80 3.5.5.3 §iÒu chØnh nguån ®iÖn vµ s¾p xÕp c¸c truyÒn t¶i......................80 3.5.5.4 Tho¶ thuËn c¸c c«ng xuÊt xö lý c¬ b¶n. ....................................81 3.5.5.5 Tr¹m thuª bao ®−îc quyÒn thùc thi sù trao ®æi chÝnh. ..............81 3.5.5.6 §¨ng ký .....................................................................................81 3.5.5.7 ThiÕt lËp kh¶ n¨ng kÕt nèi giao thøc Internet (IP).....................82 3.5.5.8 ThiÕt lËp giê cña ngµy ...............................................................82 3.5.5.9 TruyÒn c¸c tham sè to¸n tö .......................................................82 3.5.5.10 ThiÕt lËp c¸c kÕt nèi ................................................................82 3.5.6 Nh÷ng cÊp ph¸t ( Grants) vµ yªu cÇu vÒ ®é réng d¶i tÇn. ...............83 3.5.6.1 CÊp ph¸t trªn mçi kÕt nèi ( GPC)..............................................83 3.5.6.2 CÊp ph¸t trªn mét SS ( GPSS)....................................................83 3.5.7 C¸c yªu cÇu vÒ ®é réng d¶i tÇn........................................................84 3.5.7.1 C¸c giai ®o¹n yªu cÇu................................................................84 3.5.7.2 PhÇn ®Çu yªu cÇu ®é réng d¶i tÇn .............................................85 3.5.7.3 Yªu cÇu câng (Piggyback Request) ..........................................85 3.5.8 KiÓm so¸t vßng (polling).................................................................85 3.5.8.1 KiÓm so¸t vßng ®¬n h−íng (unicast)........................................86 3.5.8.2 KiÓm so¸t vßng qu¶ng b¸ (Broadcast) vµ ®a h−íng (Multicast) ...............................................................................................................87 3.5.8.3 Bit th¨m dß (Poll-Me Bit)..........................................................88 3.5.9 C¸c dÞch vô lËp lÞch tr×nh ®−êng lªn................................................89 3.5.9.1 DÞch vô cÊp ph¸t mét c¸ch tù nguyÖn ......................................90 3.5.9.2 DÞch vô kiÓm so¸t vßng thêi gian thùc......................................90 3.5.9.3 DÞch vô kiÓm so¸t vßng thêi gian kh«ng thùc...........................91 3.5.9.4 DÞch vô cã nç lùc cao nhÊt (Best Effort Service) ......................91 3.5.10 ChÊt l−îng dÞch vô ........................................................................91 3.5.11 B¶o mËt ..........................................................................................93 3.5.11.1 M· ho¸ d÷ liÖu gãi tin .............................................................94 3.5.11.2 Giao thøc qu¶n lý kho¸ ...........................................................94 3.5.11.3 Nh÷ng liªn hîp b¶o mËt ..........................................................95 3.6 KÕt luËn ...................................................................................................95 CH¦¥NG IV TriÓn khai øng dông c«ng nghÖ WiMAX ........................ 96 4.1 C¸c yÕu tè cÇn quan t©m khi triÓn khai c«ng nghÖ WiMAX ..................96 -5- LuËn v¨n tèt nghiÖp cao häc chuyªn ngµnh Xö lý Th«ng tin vµ TruyÒn th«ng niªn kho¸ 2004 - 2006 4.1.1 Ph©n vïng d©n c− .............................................................................96 4.1.2 C¸c dÞch vô cung cÊp .......................................................................98 4.1.3 Tèc ®é tiÕp nhËn thÞ tr−êng..............................................................99 4.1.4 Lùa chän d¶i tÇn sè..........................................................................99 4.1.5 C¸c kho¶n chi phÝ ®Çu t− ...............................................................100 4.1.6 ThiÕt bÞ ®Çu cuèi ............................................................................102 4.1.7 C¸c kho¶n chi phÝ vËn hµnh...........................................................102 4.1.8 Mét sè kÕt luËn khi triÓn khai kinh doanh dÞch vô WiMAX............102 4.2 T×nh h×nh triÓn khai c«ng nghÖ WiMAX ë mét sè n−íc trªn thÕ giíi ..104 4.3 TriÓn khai c«ng nghÖ WiMAX ë ViÖt Nam..........................................105 4.4 Ph−¬ng ¸n thö nghiÖm c«ng nghÖ WiMAX cña VNPT t¹i Lµo Cai .....108 4.4.1 Giíi thiÖu vÒ dù ¸n ABC/LMI WiMAX TRIAL ................................108 4.4.1.1 Môc ®Ých..................................................................................108 4.4.1.2 Vai trß c¸c bªn tham gia .........................................................109 4.4.1.3 §Þa ®iÓm, ®èi t¸c ®Þa ph−¬ng ®−îc lùa chän...........................110 4.4.1.4 Qui m« vµ thêi gian thùc hiÖn .................................................111 4.4.2 Nh÷ng øng dông c¬ b¶n cña dù ¸n ................................................111 4.4.3 Ph−¬ng ¸n kü thuËt.........................................................................112 4.4.3.1 Ph−¬ng ¸n lùa chän tÇn sè vµ thiÕt bÞ WiMAX ......................112 4.4.3.2 S¬ ®å kÕt nèi tæng thÓ..............................................................114 4.4.3.3 Ph−¬ng ¸n triÓn khai t¹i tr¹m gèc (Base Station) ....................115 4.4.3.4 Ph−¬ng ¸n triÓn khai t¹i ng−êi dïng ®Çu cuèi (End user).......117 4.4.3.5 Ph−¬ng ¸n triÓn khai øng dông VoIP ......................................118 4.4.3.6 Ph−¬ng ¸n triÓn khai øng dông Community Portal .................120 4.4.4 TriÓn khai c«ng viÖc ......................................................................120 4.4.4.1 C«ng viÖc kh¶o s¸t vµ thiÕt kÕ dù ¸n: ......................................120 4.4.4.2 §Çu t− trang thiÕt bÞ cho øng dông VoIP ................................121 4.4.4.3 §Çu t− trang thiÕt bÞ cho øng dông Community Portal ...........121 4.4.4.4 C«ng viÖc vËn hµnh øng dông trong thêi gian thö nghiÖm .....122 4.4.4.5 C«ng viÖc triÓn khai øng dông trong thêi gian thö nghiÖm.....122 4.4.5 HÖ thèng truyÒn dÉn :.....................................................................123 4.4.5.1 §Çu t− trang thiÕt bÞ cho hÖ thèng WiMAX............................123 4.4.5.2 §Çu t− trang thiÕt bÞ ®Ó kÕt nèi tíi IP backbone......................124 4.4.5.3 C«ng viÖc vËn hµnh hÖ thèng trong thêi gian thö nghiÖm.......124 4.4.5.5 C«ng viÖc triÓn khai hÖ thèng trong thêi gian thö nghiÖm......125 4.4.6 ChÝnh s¸ch ®èi víi ng−êi dïng ®Çu cuèi (End user).....................125 4.4.7 KÕ ho¹ch thùc hiÖn........................................................................126 4.5 §¸nh gi¸, nhËn xÐt vÒ c«ng nghÖ WiMAX...........................................126 4.5.1 §¸nh gi¸ vÒ mÆt kü thuËt, c«ng nghÖ .............................................126 4.5.2 §¸nh gi¸ vÒ hiÖu qu¶ kinh doanh t¹i ViÖt Nam.............................128 4.6 KÕt luËn .................................................................................................130 KÕt luËn .................................................................................................. 132 Tµi liÖu tham kh¶o ................................................................................. 134 -6- LuËn v¨n tèt nghiÖp cao häc chuyªn ngµnh Xö lý Th«ng tin vµ TruyÒn th«ng niªn kho¸ 2004 - 2006 C¸c thuËt ng÷ viÕt t¾t AES Advanced Encryption Standard AP Access Point ARG Amphibious Readiness Group ARQ Automatic Retransmission Request ATM Asynchronous Transfer Mode BS Base Station CBR Constant Bit Rate CID Connection Identifier CPS Common Part Sublayer CS Convergence Sublayer DAMA Demand Assigned Multiple Access DCD Downlink Channel Descriptor DHCP Dynamic Host Configuration Protocol DL-MAP Downlink Map FDD Frequency Division Duplexing FEC Forward Error Correction GFR Guaranteed Frame Rate GPC Grant Per Connection GPSS Grant Per Subscriber Station IE Information Element IEEE Institute of Electrical and Electronics Engineers IP Internet Protocol LAN Local Area Network LOS Line of Sight MAC Medium Access Control NLOS Non-Line of Sight OFDM Orthogonal frequency-division multiplexing OFDMA Orthogonal frequency-division multiplexing access OSI Open Systems Interconnect PDU Protocol Data Units PHY Physical Layer PKM Privacy Key Management PMP Point-to-Multipoint PTP Point-to-Point QAM Quadrature Amplitude Modulation QPSK Quadrature Phase Shift Keying QoS Quality of Service REG-REQ Registration Request -7- LuËn v¨n tèt nghiÖp cao häc chuyªn ngµnh Xö lý Th«ng tin vµ TruyÒn th«ng niªn kho¸ 2004 - 2006 REG-RSP Registration Response RF Radio Frequency RLC Radio Link Controller RNG-REQ Ranging Request RNG-RSP Ranging Response SA Security Association SDU Service Data Unit SOHO Small Office / Home Office SS Subscriber Station TC Transmission Convergence TDMA Time Division Multiple Access TDD Time Division Duplexing TDM Time Division Multiplexing UCD Uplink Channel Descriptor UDP User Datagram Protocol UIUC Uplink Interval Usage Code UL-MAP Uplink Map VLAN Virtual Local Area Network WAN Wide Area Network WEP Wireless Equivalent Privacy WiMAX Worldwide Interoperability for Microwave Access WLAN Wireless Local Area Network -8- LuËn v¨n tèt nghiÖp cao häc chuyªn ngµnh Xö lý Th«ng tin vµ TruyÒn th«ng niªn kho¸ 2004 - 2006 Danh môc h×nh H×nh 1.1: VÞ trÝ tiªu chuÈn IEEE 802.11 trong m« h×nh m¹ng OSI ................ 15 H×nh 1.2: CÊu h×nh m¹ng Wi-Fi ..................................................................... 16 H×nh 1.3: Nguyªn lý tr¶i phæ .......................................................................... 19 H×nh 1.4: Nguyªn lý tr¶i phæ d·y trùc tiÕp cã thµnh phÇn cña nhiÔu b¨ng hÑp ................................................................................................................... 20 H×nh 1.5: Phæ cña tÝn hiÖu OFDM ................................................................. 24 H×nh 1.6: M« h×nh kÕt nèi cña m¹ng Wi-Fi ........................................