Trango Broadband Wireless Access5830™ User Manual
User Manual Rev 1
42
9. Theory of Operation
This section discusses the theory of operation of the hardware and software
portion of the AP and SU and is intended as a guide to assist the reader in
understanding the system.
9.1. Hardware
9.1.1. Direct Sequence Spread Spectrum
By utilizing the same technology used for secure military communications,
robustness against interference from other radio equipment is obtained. The
method of spreading the data used by the M5830 product is similar to the
field-proven technology used for wireless LANs.
The system will operate essentially error-free even with peak signal-to-
interferer ratio of only 8.4 dB, allowing operation in noisy areas where other
non spread spectrum modulation techniques may fail. Some technologies
require peak signal-to-interferer ratios of at least 20 dB, which means that the
interfering signal must be 20 dB less than the desired signal or data loss will
occur.
9.1.2. Antenna Technology
Both the AP and SU use proprietary patch antenna technology that allows high
gain in a small package, and is electronically switchable between horizontal
and vertical polarization.
Trango Broadband chose linear polarization over circular polarization based on
field results in high RF interference environments. Most deployed equipment
uses linear polarized antennas in the 5.3 and 5.8 GHz bands, for which circular
polarization only can offer a 3 dB rejection. Linear antennas can offer
rejection of 15 to 20 dB over those same circular antennas.
9.2. Software
One of the major advantages of the Access5830 system is the ability of
the AP to handle multiple SU connections and share the 10 MBPS data
pipe efficiently according to provisioning rules set up by the
administrator.
