[ICOM] What is wrong with SMA?

Mike Clarson mclarson at rcc.com
Tue Jan 9 18:51:07 EST 2007


Adam: While what you say is correct, the FCC regulates these frequencies
slightly differently than the way the ITU allocated them. WiFi is NOT
considerd ISM, but a part 15 unlicensed operation and is not entitled to any
protection, and, must not cause any interference to authorized (primary or
secondary) stations, a group to which most of us belong. ISM equipment is
regulated under part 18 of the FCC rules, and, with the exception of some
government operations, they are primary in the 2400-2500MHz range, have no
power limit, and any radio services operating in that range must accept any
interference from these ISM devices. ISM is a place where junk is
parked--things like microwave ovens, dielectric heating devices, etc.
--Mike, WV2ZOW


-----Original Message-----
From: icom at mailman.qth.net [mailto:icom at mailman.qth.net] On Behalf Of Adam
Farson
Sent: Tuesday, January 09, 2007 4:01 PM
To: 'ICOM Reflector'
Subject: RE: [ICOM] What is wrong with SMA?

Hi John,

To address your question:

The ARS is secondary in the 2.4 GHz band. Here is the ITU allocation table
for the 2300-2450 MHz band in Region 2:

2300 - 2450 MHz
FIXED
MOBILE
RADIOLOCATION
Amateur

Footnote 664 permits the Amateur-Satellite service to operate in this band
on a secondary, non-interfering basis. 

Footnote 752: The band 2400-2500 MHz (centre frequency 2450 MHz) is
designated for industrial, scientific and medical (ISM) applications
[including WiFi]. Radio services operating within this band must accept
harmful interference which may be caused by these applications. 

Source: http://www.kloth.net/radio/freq-itu.php

In consequence, the ARRL would have no legal standing in this matter. 

The BPL case is different; the ITU requires all national administrations to
ensure that licensed radio services are protected from harmful interference
caused by utilities such as power and telecommunications networks. The ARRL'
s BPL case thus has a firm grounding in international law.

As radio amateurs, we actually benefit from band-sharing with WiFi. Several
of the Region 2 Wi-Fi channels overlap the 13cm ham band; this allows
amateur dual-use of WiFi hardware. Accessory power amplifiers and gain
antennas are permitted, but encryption is not. Several amateur groups in
this area are already using readily-available, inexpensive Wi-Fi equipment
in this manner. This certainly beats trying to build our own, especially in
this day and age.

I even have a piece of test equipment which is useful in this area. Got an
HP 8559A for Christmas!

Cheers for now, 73,
Adam VA7OJ/AB4OJ

<snip>

<< Or why did the WiFi folks find it necessary to use our
13 cm band for much of their work, and why hasn't the ARRL sued the FCC over
it like they are over BPL? >>

73s John W5TD





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