OfficeServ 500 Wireless LAN Service Manual/Ed.00 Annex A. WLAN(802.11b/DSSS) Specifications© SAMSUNG Electronics Co., Ltd. Annex A-33 Definitions and Features by Layer3.1 Physical LayerDSSS Physical LayerDSSS physical layer diffuses data to 11 bit Barker words before sending the data.11 bit Barker words have 10.4 dB of processing gain that meets FCC Part 15.247.All clients use the same 11 bit Barker words.DSSS physical layer has a total of 14 channels and null-to-null bandwidth is 22 MHz.Frequency scope is from 2.400 MHz through 2.483 MHz. It has 3 non-overlappingchannels.Modulation ways for each data rate and other information are as follows.Table A.3 Information on the Data Rate of DSSS Physical LayerData Rate Code Length Modulation Symbol Rate Bits/Symbol1 Mbps 11(Barker Sequence) BPSK 1 MSps(Mega Symbol per Sec)12 Mbps 11(Barker Sequence) QPSK 1 MSps 25.5 Mbps 8(CCK) QPSK 1.375 MSps 411 Mbps 8(CCK) QPSK 1.375 MSps 8FHSS Physical LayerFHSS physical layer supports 2 level GFSK 1 Mbps of basic rate as well as 4 levelGFSK 2Mbps optionally.It has 79 channels and the bandwidth of each channel is 1 MHz. It hops 2.5 persecond. This is a provision for spreading in FCC Part 15.247. FHSS physical layerhas 22 hop patterns as well.Infrared Physical LayerInfrared physical layer uses pulse position modulation(PPM) having 4 or 6 levels.Operating data rates are 1 Mbps and 2 Mbps.
