However, on July 12, 2004 the FCC issued a report and order that affects Part 15 devices. Some previous statements require modification based on the report and order.
The report and order is available on the FCC web site.
If after reading the report, you wish a second opinion, please send a private email and I would be happy to give you my interpretation as it relates to WLAN end-users.
Dennis Ward RF / Wireless Engineer University of Michigan
On Jul 26, 2004, at 2:17 PM, E.J. Von Schaumburg wrote:
- 802.11b - FCC 15.247
3.1.1 - Point to Multi-point
For 802.11b point to multi-point uses, you are allowed up to 30 dBm or 1
watt of Transmitter Power
Output (TPO) with a 6 dBi antenna or 36 dBm or 4 watts Effective Radiated
Power over an isotropic
antenna (EIRP). The TPO needs to be reduced 1 dB for every dB of antenna
gain over 6 dBi.
3.1.2 - Point to Point
For 802.11b point-to-point uses, the FCC encourages directional antennas to
minimize interference to
other users. The FCC in fact is more lenient with point-to-point links, as
it only requires the TPO to be
reduced by 1/3 of a dB as compared to a full dB for point to multipoint.
More specifically, for every 3 dB of antenna gain over a 6 dBi antenna, you
need to reduce the TPO 1
dB below 1 watt. For example, a 24 dBi antenna is 18 dB over a 6 dBi
antenna. You would have to
lower a 1 watt (30 dBm) transmitter 18/3 or 6 dB to 24 dBm or ¼ watt.
- 802.11a - FCC 15.407
3.2.1 - Point to Multi-point
As described before, the U-NII band, which is used for 802.11a point to
multi-point, is chopped into
three sections. The "low" band runs from 5.15 GHz to 5.25 GHz, and has a
maximum power of 50 mW
(TPO). This band is meant to be in-building only, as defined by the FCC's
Rules and Regulations Part
15.407 (d) and (e):
(d) Any U-NII device that operates in the 5.15-5.25 GHz band shall use a
transmitting antenna that
is an integral part of the device.
(e) Within the 5.15-5.25 GHz band, U-NII devices will be restricted to indoor operations to reduce any potential for harmful interference to co-channel MSS operations.
The "middle" band runs from 5.25 GHz to 5.35 GHz, with a maximum power limit
of 250 mW. Finally
the "high" band runs from 5.725 GHz to 5.825 GHz, with a maximum transmitter
power of 1 watt and
antenna gain of 6 dBi or 36 dBm or 4 watts EIRP.
3.2.2 - Point to Point
As with 802.11b, the FCC does give some latitude to 802.11a point-to-point
links in Regulation
15.407(a)(3). For the 5.725 GHz to 5.825 GHz band, the FCC allows a TPO of 1
watt and up to a 23
dBi gain antenna without reducing the TPO 1 dB for every 1 dB of gain over
23 dBi.
Regulation 15.247(b)(3)(ii) does allow the use of any gain antenna for
point-to-point operations without
reducing the TPO for the 5.725 GHz to 5.825 GHz band. You should look at the
part your equipment is
certified under to see what restrictions you have for EIRP.
Some definitions:
Effective Isotropic Radiated Power (EIRP): A measure of a signal's absolute
power in a particular direction (see ERP), but relative to an isotrope
rather than a dipole.
Effective Radiated Power (ERP): The product of the transmitter peak envelope
power, expressed in Watts, delivered to the antenna, and the relative gain
of the antenna over that of a half wave dipole antenna
Isotropic: A theoretical "isotrope" is a single point in free space which
radiates energy equally in every direction.
An isotrpoic antenna is a perfect antenna and thus does not exist.
E.J. von Schaumburg Executive Vice President, Business Development [EMAIL PROTECTED]
office: (973) 659-9009 mobile: (973) 879-4408 fax: (973) 659-0334
www.wpcs.com 3175 Route 10 East Suite 300 Denville, NJ 07844
Freedom thru thin air (tm)
-----Original Message----- From: Michael Griego [mailto:[EMAIL PROTECTED] Sent: Monday, July 26, 2004 1:11 PM To: [EMAIL PROTECTED] Subject: Re: [WIRELESS-LAN] anyone try an ap-8 yet?
http://www.hyperlinktech.com/web/antennas_5800.php
It's always legal to use an external antenna as long as the EIRP does not
exceed regulations (36dBm, or 4 watts normally). The FCC has, however,
added extra regulations in recent years pertaining to who can purchase
amplifiers. End users are required to purchase amplifier/antenna kits so as
to not exceed EIRP limits.
--
--Mike
----------------------------------- Michael Griego Wireless LAN Project Manager The University of Texas at Dallas
On Mon, 2004-07-26 at 12:00, Chris Hessing wrote:I find the 802.11a antenna connection to be interesting. I have hadis
several vendors give me different stories about 802.11a antennas on
APs. Does anyone know if using the 802.11a antennas is legal in the
US? (Or was the port put on there for use by other countries.) And if itlegal, where can you get antennas for it? I spoke with Maxrad at Interop, and they didn't seem to have any antennas that would do it.
Thanks!
---------- Chris "Spanky" Hessing Networking University of Utah [EMAIL PROTECTED] Marriott Library
Friends are people that know everything about you, but love you anyway.
On Mon, 26 Jul 2004, Michael Griego wrote:
It's the same product as the Proxim AP-4000. If you're using the Proxim/Avaya equipment, then the AP-4000 is a good upgrade. The .11G performance in my testing has been more solid than the performance of the .11G upgrade kit for the AP-2000 (Avaya AP-3). Other than that, the management interface is identical to the AP-2000/AP-3. Having antenna connectors for the .11A side is a nice new feature of the 4000s/8s.
--
--Mike
----------------------------------- Michael Griego Wireless LAN Project Manager The University of Texas at Dallas
On Mon, 2004-07-26 at 08:23, Matt Ashfield (UNB) wrote:Hi All
We currently use Avaya's Access Points on our campus, and the latest product they've released is the AP-8. I've read the pdf's and heard the supplier's details, but just thought I'd ask this group if anyone has used it and if so, what are their impressions?
Any info you can provide is greatly appreciated.
Thanks
Matthew Ashfield Network Analyst Integrated Technology Services University of New Brunswick (506) 447-3033
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