Ivan, et al, No, that is not true (unless you said PTP in error). The 36dB (4 watts) limit applies to PMP, and then only for ISM 2.4GHz and ISM 5.725-5.850GHz. For UNII (which has 100MHz of band overlapping in upper 5GHz) and also covers bands ranging now from 5.15-5.825GHz) has distinct rules, and even they vary relative to specific ranges. In any event, no band in UNII exceed 36dB from the base station. Also, in 900MHz, the 36dB applies as well to PTP.
The PTP rules for the rest of the ISM foollow what is often called the 3 to 1 rule. For every 1 dBm (the m refers to active power, like the hardware or an amp) drop, you can raise the dBi (passive gain, like an antenna) by 3dB. And when you know that every 3dB gain is double and every 3dB down is half, you can get a feel of the significance of such a rule. More to the point, you will understand the vast disappointment in the BWA industry when the FCC opened up the recent additional 255MHz between 5.47GHz and 5.725GHz, but only allowed the power rules of mid UNII, which is 1 watt (30dB) and UNII has no 3 to 1 rule. That means folks like Vivato and Navini cannot make or market their systems for those bands since their systems are 100% predicated on the use of the 3:1 rule at the base station. It also means the effective range of all our offerings from 5.25GHz to 5.725GHz will have very short range, perhaps to 2 miles, but not even then at higher order modulations likely, especially in an NLOS environment. The reason this happened is becasue these rules were essentially made in secret with the DoD, the NTIA, and the WLAN industry, though the NTIA likes to say they invited industry to participate. Only problem is that they did not tell anyone in the BWA space because they did not (and still do not entirely) understand the distinction between the last mile and the last 100 meters. Accordingly, no BWA vendors participated in the process. The WLAN industry was very happy, though -- they don't want interference from long range/last mile BWA systems. For the record, if you are deploying for broadband, then every dollar you spend on WLAN equipment supports lobbying efforts to scuttle the needs of BWA operators like WISPs. Does that mean everyone needs to buy more premium products like ours? No way. Folks like SmartBriges, Microtik, Tranzeo and others make very low cost WISP equipment and they support the BWA application. I hope this helps. Regards, Patrick Leary Assistant VP, Marketing Alvarion, Inc. ph. 760.517.3114 fax 760.517.3200 [EMAIL PROTECTED] -----Original Message----- From: Ivan Bojer [mailto:[EMAIL PROTECTED] Sent: Friday, January 30, 2004 1:13 PM To: Patrick Leary; Wireless Subject: RE: [BAWUG] Vivato and FCC part 15 Now it makes much more sense! Can you maybe confirm if cap for all other P2P systems is 36dBm EIRP according to current FCC regulations? -----Original Message----- From: Patrick Leary [mailto:[EMAIL PROTECTED] Sent: Friday, January 30, 2004 1:01 PM To: 'Ivan Bojer'; Wireless Subject: RE: [BAWUG] Vivato and FCC part 15 Vivato was granted a rare exception in terms of their certification based on the theory that their base stations antennas apply some intelligence in terms of their directionality toward the specific CPE being talked to. I can also tell you that the exception has no logical scientific rational, in that the same thing can be achieved mechanically and even then in no way reduces the levels of emissions into the cell (which was partly behind the intial rules in the first place). The FCC was trying to spur innovation and stretch the boundaries, but they also know they are on shaky legal grounds here. I know this from direct meeting with top level folks there. One such meeting was jointly attended with Vivato and WCA LEA's legal counsel. The FCC know they could very likely lose a legal battle should a competing vendor decide to confront the issue. None wish to do so as far as I know though, since partly because vendors appreciate the FCC's attempts to be forward thinking and partly because the has issued the NPRM (comments recently closed) that suggests amendments to these rules (like allowing more power in areas where the noise floor is below certain thresholds or more power when sectorization is used). This NPRM is in part a direct result of their own internal discomfort with their own granted exceptions (Navini was also given one). I hope this helps you to understand this seeming dichotmy. Regards, Patrick Leary Alvarion -----Original Message----- From: Ivan Bojer [mailto:[EMAIL PROTECTED] Sent: Friday, January 30, 2004 11:21 AM To: Wireless Subject: [BAWUG] Vivato and FCC part 15 Can anyone explain how is this device FCC compliant and at the same time has 25W (44dBm) of EIRP (look at the spec)?! I though 36dBm is the max ?! http://www.vivato.net/download/SwitchDataSheetFinalV4.pdf -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless This mail passed through mail.alvarion.com **************************************************************************** ******** This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. **************************************************************************** ******** This mail passed through mail.alvarion.com **************************************************************************** ******** This footnote confirms that this email message has been scanned by PineApp Mail-SeCure for the presence of malicious code, vandals & computer viruses. **************************************************************************** ******** -- general wireless list, a bawug thing <http://www.bawug.org/> [un]subscribe: http://lists.bawug.org/mailman/listinfo/wireless
