C S SAP ) LOP con hOMU Ogc M
331 Type (3) BR /ASS (II)
3.4. LOP Vita' Li?
Lap vat 15, cung cAp ket nSi vo tuyAn giva BS va SS. Chuan IEEE 802.16 dinh nghia cac kjl thuat khac nhau de truyen thong tin qua mei trubng ye tuyen.
Chu'an IEEE 802.16 hi try 2 bang tin: bang tan 10-66 GHz va 2-11 GHz.
Bang tan 10-66 GHz ho try cho cac mai truong truyen din you eau tam nhin thing LOS, khong co vat can gifts tram phat vi tram thu. Dac ti giao tiep khong gian (air interface) tai bang tan 10-66 Ghz duqc gyi la WirelessMAN-SC, sir dung phucmg thirc truy cap TDMA (Time Division Multiplexing Access) cho huong truyen uplink va phuong thirc truy cap TDM (Time Division Multiplexing) cho huong truyen downlink.
Bang tin 2-11 GHz (cAp phep va khong cap phep) 116 try m6i truimg truyen din khong c6 tam nhin thing NLOS, tin hieu c6 the truyen qua cac vat can theo nhieu each khac nhau.
Co 5 dac ti 16p vat IS, chuan IEEE 802 16 duqc mo ti trong bang ben du6i:
Chet Fling LOS! NLOS Sang tan Kitiu song mang Kik song ding VVirelessMAN Sc PoinP oint-to- t LOS 10-86 GHz Single TDD, FDD
WirelessMAN SCa Point-to- Point LOS 2-11 GHz Licensed Single TDD, FDD WirelessMAN OFDM Point-to- MultiPoint NLOS 2-11 GHz Licensed 256 TDD, FDD WirelessMAN OFDMA Point-to- MultiPoint NLOS 2-11 GHz Licensed 2048 TDO. FDD VArcolessHUMAN (High-speed Unlicensed) poinwo. munipoint NLOS 2.11 GHz Licensed Exempt
1/2562048 TFreq Selected DD Dynamic
Bang 3.3. 194c to vat iy chudn IEEE 802.16
LOp vat IS, chtfan IEEE 802.16 sir dung phucmg phip dieu the OFDM, bang tin duqc chia thinh nhieu song mang con true giao yeti nhau nhim dat duqc thong luyng da wou vi khoang each truyen tai da, cheng nhiiu hiOu qua.
Ngoai ra, 16p vat IS, can cung cap mOt s6 phucmg thirc dieu the nhieu mire iglu BPSK, QPSK, 16-QAM, 64-QAM...cho phep truyen nhieu don vi thong tin tra mt don vi thin gian.
LOp vat 15, h6 try ca 2 phucmg thirc truyen song cong : song ding phan chia theo thoi gian TDD (Time Division Duplex) vi song cong phan chia theo tan se FDD (Frequency Division Duplex). Che dO TDD sir dung cac khe died gian, m6i mOt SS
Chuang 3: Kiln frac mgng troy cap WIMAX
dirge BS cap cho cac khe thin gian sir dung de truyen va nhan du lieu, cho phep du lieu truyen kheing dOng theri tren el hai Wong uplink va downlink nhung co the sir dung chung tan so. Chet do song ding FDD phin chia thinh hai kenh uplink va downlink hoat dOng tren hai tin s6 rieng biet, cho phop truyen dir lieu tiling thtri tren ca hai huerng.
Cac qua trinh Ranging va DFS (Dynamic Frequency Selection) dugc thin thi tai lop vat ber.
Ranging la qua trinh thwc hien dieu chinh c8ng suit phat cita tram BS den tram SS phii hgp voi vi tri ciut tram SS.
DFS la qua trinh tkr dOng qua dai tin danh rieng cho SS tie tim mot Gin s6 hoat dOng phu hqp.
Chuang 3: Kiln trzic mang truy cap WIMAX