Wilan LIBRA 5800 AP, User Manual

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Description
14 Libra 5800 Series User Guide
About W-OFDM
The Libra system uses Wi-LAN’s patented Wide-band Orthogonal Frequency Division Multiplexing
(W-OFDM) technology to process, transmit and receive data in parallel fashion over the air. W-
OFDM divides a wide RF frequency band into several subchannels that work together to deliver
data, similar to splitting a road into several lanes that together can handle more traffic than a single
lane.
W-OFDM offers many advantages, including effective use of bandwidth, resistance to interference,
ability to take advantage of multipath characteristics, and advanced error correction and recovery.
Because data is spread across all the channels, interference usually affects only a few channels
rather than all channels, and lost data can be easily recovered. Since W-OFDM is insensitive to
interference, the amount of ongoing tuning, adjustment and maintenance is minimized. Both
multipoint networks and point-to-point backbone systems are supported.
The following diagram illustrates the main concept behind W-OFDM. The available frequency
spectrum is divided into subchannels. Each subchannel is orthogonal, meaning that the peak signal
strength of each signal occurs at the null or point of minimum signal strength of its neighbor, so
adjacent subchannels do not interfere with each other. Data is carried in parallel across the
subchannels.
Orthogonal Arrangement of W-OFDM Subchannels
Si
gn
al
S
tre
ng
th
Frequency
Subchannel (shaded for clarity)
Null
Zone
Operating
Frequency Range