Tong Quan WIFI - WiMAX.docx

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<p>S lc v cng ngh WIFI &amp; WIMAX</p> <p>HC VIN CNG NGH BU CHNH VIN THNGKHOA CNG NGH THNG TIN</p> <p> ti tiu lun</p> <p>S lc v cng ngh WIFI &amp; WIMAX</p> <p>Lp cao hc CH10CNK1</p> <p>Ging vinPhm Th Qu.</p> <p>Nhm thc hin:-</p> <p>ng Tuyt Chinh. Nguyn L Phng. V Th Mai. Phm Th Trang. ng c Dng Nguyn H Nguyt.</p> <p>H Ni 10/2010</p> <p>Hc vin cng ngh Bu chnh Vin Thng</p> <p>1</p> <p>S lc v cng ngh WIFI &amp; WIMAX</p> <p>Mc lcTNG QUAN V MNG KHNG DY Mng khng dy l g u im: Nhc im: Phn loi mng khng dy A. B. Da trn vng ph sng, mng khng dy c chia thnh 5 nhm: Da trn cc cng ngh mng, mng khng dy c chia thnh 3 loi: 4 4 4 5 6 6 8 8 8 9 11 11 12 13 13 13 14 14 15 16 16 16 19 19 20 21 21 22 23 25</p> <p>Cc m hnh mng khng dy A. B. WIFI Khi nim wifi Dng chun 802.11 A. B. C. D. E. Original IEEE 802.11 LAN Standard IEEE 802.11b IEEE 802.11a IEEE 802.11g IEEE 802.11n M hnh mng AD-HOC: M hnh mng INFRASTRUCTURE</p> <p>Hot ng ca mng wifi A. B. C. D. E. F. Tn s hot ng Gii hn v mnh tn hiu Tc d liu bng thng Knh Cc tham s cu hnh im truy cp khng dy v nh tuyn</p> <p>Bo mt trong mng wifi Gii thiu Bo mt bng WEP (Wired Equivalent Privacy) Bo mt bng WPA (Wifi Protected Access ) Tng cng bo mt vi chun 802.11i</p> <p>Hc vin cng ngh Bu chnh Vin Thng</p> <p>2</p> <p>S lc v cng ngh WIFI &amp; WIMAXPhng php ti u v mt s bin php gi mng Wifi an ton Kt lun WiMax Tng quan v WiMax c im. Cc chun WiMAX Chun 802.16 Cu trc mng (Network Topology) Chng giao thc (Protocol stack) Cng ngh iu ch Cng ngh song cng. Cng ngh ghp knh Cht lng dch vu Cc chun b sung ca WiMAX 802.16a 802.16b 802.16c 802.16d 802.16e Vn bo mt Cc im yu trong bo mt ca WiMAX Bin php tng cng bo mt cho WiMAX Kt lun u im v ng dng</p> <p>Hc vin cng ngh Bu chnh Vin Thng</p> <p>3</p> <p>S lc v cng ngh WIFI &amp; WIMAX</p> <p>TNG QUAN V MNG KHNG DYMng khng dy l gMng khng dy l mt h thng cc thit b c nhm li vi nhau, c kh nng giao tip thng qua sng v tuyn thay v cc ng truyn dn bng dy. Ni mt cch n gin mng khng dy l mng s dng cng ngh m cho php hai hay nhiu thit b kt ni vi nhau bng cch s dng mt giao thc chun, nhng khng cn kt ni vt l hay chnh xc l khng cn s dng dy mng (cable). V y l mng da trn cng ngh 802.11 nn i khi cn c gi l 802.11 mng Ethernet, nhn mnh rng mng ny c gc t mng Ethernet 802.3 truyn thng. V hin ti cn c gi l mng Wireless Ethernet hoc Wi-Fi (Wireless Fidelity).</p> <p>u im:Tnh d dng kt ni v thun tin trong s dng lm cho mng Wireless nhanh chng ngy cng ph bin trong cuc sng chng ta, h tr tch cc trong cng vic ca chng ta. - Gi thnh gim nhiu i vi mi thnh phn ngi s dng. - Cng ngh khng dy c tch hp rng ri trong b vi x l dnh cho my tnh xch tay ca INTEL v AMD, do tt c ngi dng my tnh xch tay u c sn tnh nng kt ni mng khng dy. - Mng Wireless cung cp tt c cc tnh nng ca cng ngh mng LAN nh Ethernet v Token Ring m khng b gii hn v kt ni vt l (gii hn v cable). - Tnh linh ng: to ra s thoi mi trong vic truyn ti d liu gia cc thit b c h tr m khng c s rng but v khong cch v khng gian nh mng c dy thng thng. Ngi dng mng Wireless c th kt ni vo mng trong khi di chuyn bt c ni no trong phm vi ph sng ca thit b tp trung (Access Point). - Mng WLAN s dng sng hng ngoi (Infrared Light) v sng Radio (Radio Frequency) truyn nhn d liu thay v dng Twist-Pair v Fiber Optic Cable. Thng thng th sng Radio c dung ph bin hn v n truyn xa hn, lu hn, rng hn, bng thng cao hn. - Cng ngh Wireless bao gm cc thit b v h thng phc tp nh h thng WLAN, in thoi di ng (Mobile Phone) cho n cc thit b n gin nh tay nghe khng dy, microphone khng dy v nhiu thit b khc c kh nng truyn</p> <p>Hc vin cng ngh Bu chnh Vin Thng</p> <p>4</p> <p>S lc v cng ngh WIFI &amp; WIMAX nhn v lu tr thng tin t mng. Ngoi ra cng bao gm c nhng thit b h tr hng ngoi nh Remote, in thoi truyn d liu trc din gia 2 thit b.</p> <p>Nhc im:Bn cnh nhng u im ca mng Wireless nh l tnh linh ng, tin li, thoi mith mng Wireless vn khng th thay th c mng c dy truyn thng. Thun li chnh ca s linh ng l ngi dng c th di chuyn. Cc Server v my ch c s d liu phi truy xut d liu, v v tr vt l th khng ph hp (v my ch khng di chuyn thng xuyn c). - Tc mng Wireless b ph thuc vo bng thng. Tc ca mng Wireless thp hn mng c nh, v mng Wireless chun phi xc nhn cn thn nhng frame nhn trnh tnh trng mt d liu. - Trong mng c nh truyn thng th tn hiu truyn trong dy dn nn c th c bo mt an ton hn. Cn trn mng Wireless th vic nh hi rt d dng bi v mng Wireless s dng sng Radio th c th b bt v x l c bi bt k thit b nhn no nm trong phm vi cho php, ngoi ra mng Wireless th c ranh gii khng r rng cho nn rt kh qun l. - Bo mt trn mng Wireless l mi quan tm hng u hin nay. Mng Wireless lun l mi bn tm v s giao tip trong mng u cho bt k ai trong phm vi cho php vi thit b ph hp. Trong mng c nh truyn thng th tn hiu truyn trong dy dn nn c th c bo mt an ton hn. Cn trn mng Wireless th vic nh hi rt d dng bi v mng Wireless s dng sng Radio th c th b bt v x l c bi bt k thit b nhn no nm trong phm vi cho php, ngoi ra mng Wireless th c ranh gii khng r rng cho nn rt kh qun l. Bng so snh h thng Mng Khng dy v Mng C dy H thng Tc Mng Khng dy 11/54/108Mbps Bo mt khng m bo bng c dy do pht sng thng tin ra mi pha Thi cng trin khai nhanh Mng C dy 10/100/1000Mbps Bo mt m bo ch b l thng tin nu can thip thng vo v tr dy dn Thi cng phc tp do phi thit k</p> <p>Bo mt</p> <p>Thi cng v</p> <p>Hc vin cng ngh Bu chnh Vin Thng</p> <p>5</p> <p>S lc v cng ngh WIFI &amp; WIMAX trin khai Kh nng m rng v d dng Kh nng m rng khong cch tt vi chi ph hp l Cc v tr kt ni mng c th thay i m khng cn phi thit k li i dy cho ton b h thng i hi chi ph cao khi mun m rng h thng mng c bit l m rng bng cp quang Cc v tr thit k khng c ng phi thit k li nu thay i cc v tr kt ni mng</p> <p>Tnh mm do</p> <p>Phn loi mng khng dyC nhiu cch phn loi: A. Da trn vng ph sng, mng khng dy c chia thnh 5 nhm:</p> <p>Hnh 1: Phn loi mng v tuyn WPAN: mng v tuyn c nhn. Nhm ny bao gm cc cng ngh v tuyn c vng ph nh tm vi mt n hng chc mt ti a. Cc cng ngh ny phc v mc ch ni kt cc thit b ngoi vi nh my in, bn phm, chut, a cng, kha USB,Hc vin cng ngh Bu chnh Vin Thng 6</p> <p>S lc v cng ngh WIFI &amp; WIMAX ng h,...vi in thoi di ng, my tnh. Cc cng ngh trong nhm ny bao gm: Bluetooth, Wibree, ZigBee, UWB, Wireless USB, EnOcean,... a phn cc cng ngh ny c chun ha bi IEEE, c th l nhm lm vic (Working Group) 802.15. Do vy cc chun cn c bit n vi tn nh IEEE 802.15.4 hay IEEE 802.15.3 ... WLAN : mng v tuyn cc b. Nhm ny bao gm cc cng ngh c vng ph tm vi trm mt. Ni bt l cng ngh Wifi vi nhiu chun m rng khc nhau thuc gia nh 802.11 a/b/g/h/i/... Cng ngh Wifi gt hi c nhng thnh cng to ln trong nhng nm qua. Bn cnh WiFi th cn mt ci tn t nghe n l HiperLAN v HiperLAN2, i th cnh tranh ca Wifi c chun ha bi ETSI. WMAN: mng v tuyn th. i din tiu biu ca nhm ny chnh l WiMAX. Ngoi ra cn c cng ngh bng rng BWMA 802.20. Vng ph sng ca n s tm vi km (tm 4-5km ti a). WWAN: Mng v tuyn din rng: Nhm ny bao gm cc cng ngh mng thng tin di ng nh UMTS/GSM/CDMA2000... Vng ph ca n cng tm vi km n tm chc km. WRAN: Mng v tuyn khu vc. Nhm ny i din l cng ngh 802.22 ang c nghin cu v pht trin bi IEEE. Vng ph c n s ln tm 40-100km. Mc ch l mang cng ngh truyn thng n cc vng xa xi ho lnh, kh trin khai cc cng ngh khc. So snh cc nhm mng: Cng ngh Mng Chun Tc 110-480 Mbps Trn Kbps Trn Mbps 720 Vng ph sng Trn 30 feet Bng tn 7.5 GHz</p> <p>UWB (Ultra WPAN wideband) Bluetooth WPAN</p> <p>802.15.3a</p> <p>802.15.1</p> <p>Trn 30 feet 300</p> <p>2.4 GHz</p> <p>Wi-Fi</p> <p>WLAN</p> <p>802.11a</p> <p>54 Trn feet</p> <p>5 GHz</p> <p>Hc vin cng ngh Bu chnh Vin Thng</p> <p>7</p> <p>S lc v cng ngh WIFI &amp; WIMAX Trn Mbps Trn Kbps Trn Mbps Trn Mbps 11 Trn feet 384 4-5 dm 300</p> <p>Wi- Fi Edge/GPRS (TDMA- GMS)</p> <p>WLAN</p> <p>802.11b</p> <p>2.4 GHz 1900 MHz 400-2100 MHz 18002100 MHz</p> <p>WWAN</p> <p>2.5 G</p> <p>CDMA 2000/1x WWAN EV-DO WCDMA/ UMTS</p> <p>3G</p> <p>2.4</p> <p>1-5 dm</p> <p>WWAN</p> <p>3G</p> <p>2</p> <p>1-5 dm</p> <p>Tt c cc cng ngh ny u ging nhau ch chng nhn v chuyn tin bng cch s dng sng in t (EM). B. Da trn cc cng ngh mng, mng khng dy c chia thnh 3 loi: - Kt ni s dng tia hng ngoi. - S dng cng ngh Bluetooth. - Kt ni bng chun Wi-fi.</p> <p>Cc m hnh mng khng dyA. M hnh mng AD-HOC: a. Khi nim: o L mng gm hai hay nhiu my tnh c trang b card khng dy. o Tng t m hnh peer to peer trong mng c dy. o Cc my tnh c vai tr ngang nhau. o Khong cch lin lc 30-100m. o S dng thut ton Spokesman Election Algorithm(SEA).</p> <p>Hc vin cng ngh Bu chnh Vin Thng</p> <p>8</p> <p>S lc v cng ngh WIFI &amp; WIMAX b. M hnh vt l:</p> <p>c. Cch thit lp: o Thit b: Card khng dy. o Driver. o Tin ch. d. Cu hnh o Cc Staion phi cng BSSID. o Cc Staion phi cng knh. o Cc Station phi cng tc truyn. B. M hnh mng INFRASTRUCTURE a. Khi nim:Hc vin cng ngh Bu chnh Vin Thng 9</p> <p>S lc v cng ngh WIFI &amp; WIMAX L mng gm mt hay nhiu AP(Access Point) m rng phm vi hot ng ca cc Station c th kt ni vi nhau vi mt phm vi gp i. AP ng vai tr l im truy cp cho cc trm khch trao i d liuvi nhau v ruy xut ti nguyn ca my ch. Mi AP c th lm im truy cp cho 10-15 my khch (ty sn phm v hng sn xut) ng thi ti mt thi im. b. M hnh vt l:</p> <p>c. Cch thit lp o Thit b: o Card mng khng dy. o Access Point. o Driver. o Tin ch. d. Cu hnh o Cc Station phi cng BSSID vi AP.</p> <p>Hc vin cng ngh Bu chnh Vin Thng 10</p> <p>S lc v cng ngh WIFI &amp; WIMAX o Cc Station phi cng knh vi AP. o Cc Ap phi cng mt ESID nu mun h tr roaming.</p> <p>WIFIKhi nim wifiWi-Fi vit tt t Wireless Fidelity hay mng 802.11 l h thng mng khng dy s dng sng v tuyn, ging nh in thoi di ng, truyn hnh v radio. H thng ny hot ng mt s sn bay, qun caf, th vin hoc khch sn. H thng cho php truy cp Internet ti nhng khu vc c sng ca h thng ny, hon ton khng cn n cp ni. Ngoi cc im kt ni cng cng (hotspots), WiFi c th c thit lp ngay ti nh ring. Tn gi 802.11 bt ngun t vin IEEE (Institute of Electrical and Electronics Engineers) Vin k thut in v in t M. Vin ny a ra nhiu chun cho nhiu giao thc k thut khc nhau, v n s dng mt h thng s nhm phn loi chng; 3 chun thng dng ca WiFi hin nay l 802.11a/b/g. Trong mt mng Wi-Fi, my tnh v card mng wifi kt ni khng dy n mt b nh tuyn khng dy (router). Router c kt ni vi Internet bng mt modem, thng l mt cp hoc modem DSL. Bt k ngi dng trong vng 200 feet hoc hn (khong 61 mt) ca cc im truy cp sau c th kt ni vi Internet, d cho tc truyn ti tt, khong cch 100 feet (30,5 m), hoc t c ph bin hn. Cc tn hiu khng dy c th m rng phm vi ca mt mng khng dy. Mng wifi c th c "m", nh vy m ai cng c th s dng, hoc "ng" trong trng hp s dng mt mt khu. Mt khu vc bao ph truy cp khng dy thng c gi l mt im nng khng dy. C nhng n lc tin hnh chuyn ton b thnh ph, nh San Francisco, Portland, v Philadelphia, thnh im nng khng dy ln. Nhiu ngi trong s cc k hoch ny s cung cp min ph, dch v h tr qung co, dch v qung co min ph cho mt khon ph nh. San Francisco gn y chn Google cung cp cho n vi mt mng khng dy. Wifi s dng cng ngh v tuyn lin lc, thng thng hot ng tn s 2.4GHz. Wifi l cng ngh c thit k phc v cho cc h thng my tnh nh ca tng lai,Hc vin cng ngh Bu chnh Vin Thng 11</p> <p>S lc v cng ngh WIFI &amp; WIMAX l in thoi di ng v thit k tiu th in nng ti thiu. PDA, my tnh xch tay, v cc ph kin khc nhau c thit k tng thch vi wifi. Thm ch cn c in thoi c pht trin m c th chuyn i lin mch t cc mng di ng vo mng wifi m khng cn b mt cuc gi. Li ch ca wifi - Wireless Ethernet. Wi-Fi l mt thay th Ethernet. Wi-Fi v Ethernet, c hai mng IEEE 802 chia s mt s yu t ct li. - Extended Access. S vng mt ca dy v cp m rng truy cp vo nhng ni c dy v cp in khng th i hoc ni m n l qu t i vi h i. - Chi ph gim. Nh cp trn, s vng mt ca dy v cp in mang li xung gi. iu ny c thc hin bi s kt hp ca cc yu t, chi ph tng i thp ca cc b nh tuyn khng dy, khng cn o ho, khoan v cc phng php khc c th l cn thit lm cho cc kt ni vt l. - Vn ng. C dy buc bn c nh mt a im. Vi khng dy bn c th t do thay i v tr ca bn m khng b mt kt ni ca bn. - Tnh linh hot. M rng truy cp, gim chi ph, v tnh di ng to c hi cho cc ng dng mi cng nh kh nng ca gii php sng to mi cho cc ng dng di sn.</p> <p>Dng chun 802.11Mng WLANs hot ng da trn chun 802.11 (802.11 c pht trin t nm 1997 bi nhm Institute of Electrical and Electronics Engineers), chun ny c xem l chun dng cho cc thit b di ng c h tr Wireless, phc v cho cc thit b c phm vi hot ng tm trung bnh. Cho n hin ti IEEE 802.11 gm c 4 chun trong h 802.11 v 1 chun ang th nghim: - 802.11 - l chun IEEE gc ca mng khng dy (hot ng tng s 2.4GHz, tc 1 Mbps 2Mbps). - 802.11b - (pht trin vo nm 1999, hot ng tng s 2.4-2.48GHz, tc t 1Mpbs - 11Mbps). - 802.11a - (pht trin vo nm 1999, hot ng tng s 5GHz 6GHz, tcHc vin cng ngh Bu chnh Vin Thng 12</p> <p>S lc v cng ngh WIFI &amp; WIMAX 54Mbps). - 802.11g - (mt chun tng t nh chun b nhng c tc cao hn t 20Mbps - 54Mbps, hin ang ph bin nht). - 802.11e - l 1 chun ang th nghim: y ch mi l phin bn th nghim cung cp c tnh QoS (Quality of Service) v h tr Multimedia cho gia nh v doanh nghip c mi trng mng khng dy. - Thc t cn mt vi chun khc thuc h 802.11 l: 802.11F, IEEE 802.11h, IEEE 802.11j, IEEE 802.11d, IEEE 802.11s. Mi chun c b sung nhiu tnh nng khc nhau. A. Original IEEE 802.11 LAN Standard Nm 1997, IEEE (Institute of Electrical and Electronics Engineers )to ra chun u tin ca WLAN, gi l 802.11 sau tn ca nhm pht trin (IEEE 802.11). Tuy nhin, 802.11 ch h tr mng bng thng ti a l 2Mbps (hot ng 2.4GHz vi tc l 1Mpbs hoc 2Mpbs)- qu chm cho hu ht cc ng dng. Do , cc sn phm 802.11 khng cn c sn xut. B. IEEE 802.11b IEEE m rng chun 802.11 ban u vo thng 7 nm 1999, to ra chun 802.11b. 802.11b cung cp bng thng ln ti 11Mbps (hot ng tng s 2.4GHz v tc tng dn 1Mpbs, 2Mpbs, 5,5Mpbs v 11Mpbs. 802.11b s dng tn s sng radio khng cn ng k 2.4GHz nh l chun 802.11. Nh sn xut thng thch s dng tn s ny lm gim gi thnh sn phm. Bi v s dng tn s khng ng k, cc thit b 802.11b c th xy ra nhiu t nhng sn phm cng s dng tn s nh l l vi sng, in thoi m bng con (cordless phones) v rt nhiu sn phm ng dng cng s dng di tn 2.4. Tuy nhin, ch cn lp t thit b 802.11b xa nhng thit b khc, nhng vn nhiu d dng c gii quyt. - u im: gi thnh r, di tn hiu tt v khng d dng b tc nghn. - Nhc im: Tc thp nht, lp t nh d b nhiu bi cc thit b cng di tn khng ng k. C. IEEE 802.11a Song hnh vi 802.11b, IEEE tip tc a ra chun m rng th hai cng da vo 802.11 u tin - 802.11a. Chun 802.11a s dng tn s 5GHz, tc 54Mbps trnhHc vin cng ngh Bu chnh Vin Thng 13</p> <p>S lc v cng ngh WIFI &amp; WIMAX c can nhiu t cc thit b dn dng. ng thi, chun 802.11a cng s dng k thut tri ph khc vi chun 802.11b - k thut tri ph theo phng php a phn chia tn s trc giao (Orthogonal Frequency Division Multiplexing-OFDM). y c coi l k thut tri hn so vi tri ph trc tip (DSSS). Do chi ph cao hn, 802.11a thng ch c s dng trong cc mng doanh nghip, ngc li, 802.11b thch hp hn cho nhu cu gia nh. Tuy nhin, do tn s cao hn tn s ca chun 802.11b nn tn hin ca 802.11a gp nhiu kh khn hn khi xuyn tng v cc vt cn khc. Do 802.11a v 802.11b s dng tn s khc nhau, hai cng ngh ny khng tng thch vi nhau. Mt vi hng sn xut bt u cho ra i sn phm "lai" 802.11a/b, nhng cc sn phm ny ch n thun l cung cp 2 chun sng Wi-Fi cng lc (my trm dng chun no th kt ni theo chun ). u im: tc nhanh, khng b nhiu vi nhng thit b khc. Nhc: gi thnh cao, bc sng ngn nn d b cn.</p> <p>D. IEEE 802.11g Vo nm 2002 - 2003, sn phm WLAN c cung cp mt chun mi c tn gi l 802.11g. 802.11g l kt hp u im ca hai chun 802.11a v 802.11b: cung cp bng thng ln ti 54mbps v s dng di tn 2.4 cho cc thit b pht sng. V 802.11g hot ng cng tn s vi 802.11b, ngha l cc im truy cp (access point AP) 802.11g s lm vic vi card mng Wi-Fi chun 802.11b... Thng 7/2003, IEEE ph chun 802.11g. Chun ny cng s d...</p>