Interesting People mailing list archives
Re: Long-Distance Wi-Fi
From: David Farber <dave () farber net>
Date: Tue, 25 Mar 2008 04:16:26 -0700
________________________________________ From: Lars Poulsen [lars () beagle-ears com] Sent: Tuesday, March 25, 2008 1:25 AM To: David Farber Subject: Re: [IP] Re: Long-Distance Wi-Fi From: Brett Glass [brett () lariat net]
What the article fails to mention is that this technology would not be legal to use in the United States due to the FCC's restrictions on effective isotropic radiated power. Our wireless ISP has long advocated that the FCC allow broadband providers to use additional power to reach outlying areas, subject to the use of spectrum etiquettes to avoid interference.
What the article describes should be feasible under FCC's ISM rules for the 2.4GHz band. You may have overlooked the rule that allows an increase in EIRP for point-to-point links with directional antennas at both ends. With 24dBi antennas at both ends and 20dBm transmit power, you can get 69 miles at -90 dBm sensitivity. (Try the RF link budget calculator at http://www.afar.net/rf-link-budget-calculator/ ). My company routinely provides equipment for the provisioning of such links, albeit at lower data rates (2.75 Mbps raw link speed and below) for scientific and industrial data collection applications. As pointed out in the cited article, WiFi protocol is not suited for this. Our equipment, like the system described in the article, uses strictly controlled time slots to accomplish this, as well as to synchronize multiple links on the same tower to avoid mutual interference. / Lars Poulsen Afar Communications Inc ------------------------------------------- Archives: http://www.listbox.com/member/archive/247/=now RSS Feed: http://www.listbox.com/member/archive/rss/247/ Powered by Listbox: http://www.listbox.com
Current thread:
- Long-Distance Wi-Fi David Farber (Mar 19)
- <Possible follow-ups>
- Re: Long-Distance Wi-Fi David Farber (Mar 19)
- Re: Long-Distance Wi-Fi David Farber (Mar 19)
- Re: Long-Distance Wi-Fi David Farber (Mar 25)
- Re: Long-Distance Wi-Fi David Farber (Mar 25)