- 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 had > 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 it is > legal, 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 > > > > > > ********** > > > Participation and subscription information for this EDUCAUSE > > > Constituent Group discussion list can be found at > > > http://www.educause.edu/cg/. > > > > ********** > > Participation and subscription information for this EDUCAUSE > > Constituent Group discussion list can be found at > > http://www.educause.edu/cg/. > > > > ********** > Participation and subscription information for this EDUCAUSE > Constituent Group discussion list can be found at > http://www.educause.edu/cg/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/cg/. ********** Participation and subscription information for this EDUCAUSE Constituent Group discussion list can be found at http://www.educause.edu/cg/.
E. von Schaumburg ([EMAIL PROTECTED]).vcf
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