Wireless System Overview

Among the physical layers, .11, .11b, .11a, .11g and Draft n offer progressive speeds over the course of development, which are as follows


StandardYearModulationPeak Rate Peak Throughput
.111999DSSS2 Mbps1 Mbps
.11b1999CCK11 Mbps 6 Mbps
.11a1999OFDM54 Mbps25 Mbps
.11g2003OFDM54 Mbps 22 Mbps
Draft n2006MIMO OFDM300 Mbps180 Mbps

Also available are security features vital to wireless protection; QoS support that improves the service quality when service compromise becomes inevitable; radar detection that avoids interference with airport or weather Radar operations.

Users should evaluate application needs carefully and tailor the product appropriately. A sample of video application requirements are listed as follows:

SDTV5 Mbps
Cable Modem6 Mbps
DVD9.8 Mbps
HDTV12.9 Mbps
ADSL2+20 Mbps
FTTH30 Mbps
HD DVD36 Mbps
Blue-ray DVD48 Mbps
VDSL50 Mbps

Video streaming is very demanding in frame errors, e.g., FER < 10-4 or tighter, so the peak throughput of a specific WLAN device is recommended to scale down to one-third of its original value for budgetary purposes. For example, a peak throughput of 15 Mbps is necessary for satisfactory SDTV streaming at 5 Mbps in general.

Ralink offers a full array of WLAN products including the latest Draft-n chipset. Peak throughput exceeds 180 Mbps in lab tests, which meets all of the above video application requirements with ease.