User Guide

AB-Access Config & User Guide 5.5 Axxcelera Broadband Wireless
July 27, 2004 Company Confidential Page 23 of 129
5 RF Design and Planning
5.1 Overview
The AB-Access system is a communications system using wireless technology in the U-NII,
ISM and ESTI frequency bands. Therefore understanding Radio Frequency (RF) system design is
necessary to ensure gook link quality and, thus, good system performance. This section discusses the
basics of RF Design and Planning from the perspective of deploying the AB-Access System.
5.2 The U-NII, ISM and ETSI Channel Plan
In 1997 the FCC amended its Part 15 rules to make 300 MHz of spectrum available for high-
speed wireless digital communications with unlicensed operation. This band, called the Unlicensed
National Information Infrastructure or U-NII band, provides the spectrum at 5.15 to 5.25 GHz for
indoor use, and 5.25 to 5.35 and 5.725 to 5.825 GHz for outdoor use. The peak output power
permitted is limited to 23 dBm EIRP in the lower (indoor) band, 30 dBm in the mid-band, and 36
dBm in the upper band.
The 5.8 GHz ISM (Industrial Scientific and Medical) band ranges from 5.725-5.850 GHz.
Which is an unlicensed frequency limited to 36 dBm for PTMP equipment. The limit for PTP is
higher than PTMP.
The 5.8 GHz ETSI (European Telecommunications Standard Institute) variant consists of two
bands (5.725–5.795 GHz and 5.815–5.850 GHz). These are unlicensed, limited to 2 Watts EIRP (3
dBW) and 100mW/MHz PSD.
NOTE: AB-Access uses both the U-NII and ISM band for its upper band channels.
NOTE: AB-Access uses a different channel scheme for ESTI bands.
NOTE: BPSK modulation is only approved by the FCC for the upper band channels.
5.3 Air Interface
The SU talks to the AP over a proprietary airlink protocol on a single 15 MHz channel using
QPSK or BPSK modulation and a technique called Time Division Duplex (TDD). Both upstream and
downstream traffic time-share this channel.