Best of the ISP-Lists

Fixed Wireless Equipment

802.11a Backhaul

How many viable wireless backhaul solutions are there? Members of ISP-Wireless might well answer the question with another question: "How many kinds of radios are there?"

[August 19, 2003]

In the discussion of an ongoing quest that never quite seems fulfilled, KR asked last March:

"What about 802.11a backhauls? That probably sounds like a no-brainer, seeing as those are nicely high bandwidth, but I haven't researched it much. Been sticking with .11b. Anyone have good experiences with equipment?"

[JR echoed the question] "I have been thinking of using .11a on some backhauls, but I can't find any that is FCC certified. Everyone is using the lower two bands, which, from the way I understand it, will not be outdoor certified. Anyone have some more up to date info?"

[MV clarified] "The issue with indoor/outdoor is that the lower 5 GHz band is only authorized for indoor use, and limited EIRP. The middle 5 GHz band is authorized for indoor or outdoor but also has limited EIRP. The upper band, which allows higher EIRP, is restricted to outdoor use only.

Since the 802.11a standard was designed primarily for WLAN applications, the products using 802.11a are not designed for outdoor use. I don't know of any products that are 802.11a compliant and also work in the 5.8 GHz band. If they are 802.11a compliant, I don't think they will be very competitive in the long run anyway since 802.11a was designed for WLAN use. The 802.16a standard was designed for outdoor use."

[F commented] "I assume that when you say backhaul, you mean BACKHAUL. I started my service with a Lucent Orinoco as the backhaul. When the traffic on my network grew above 1 Mbps, my subscribers started to complain—until I installed a YDI EX-1. 802.11b is no good for backhaul. If your network traffic is above 1 Mbps, please get a purpose-built backhaul radio; there are many of them. They may be expensive but they are well worth the extra dosh. These companies all make good backhaul radios, choose one.

  - Alvarion
  - Aperto
  - Motorola
  - WMux/Proxim
  - YDI"

[JR further explained his project] "This is to reach a small town that will have 1 Mbps. This is a stop-gap measure until .16g arrives—or if the town blooms and requires more bandwidth, we will change the hardware. We are considering Trango, Canopy, and Redline. Many others too and more as .16g is released."

[J inquires] "The distance is . . . ? I would go Trango if it is under 10 miles, Redline if it is farther than that. A Trango SU-to-OU works really well in a point-to-point scenario and will deliver 10 Mbits without breaking a sweat, again—depending on distance."

[J responds to TS's original post] "We have used Lucent for this in the past and found that although it works quite well, carries a good amount (you get over 1 to 5 miles with it), and is quite reliable, it is subject to a lot of interference. I do not care how well tuned it is, or what your line of sight is; any little thing in the path is gonna be problematic. (Your results may vary, however.) We have some links that work wonderfully at 12 miles and others that had to be replaced with 5.8 GHz solutions. The biggest culprit has been Cell carriers, 2.4 GHz backhauls, and little organizations in the path that had to have 5000 Linksys APs per square foot for their "in building" wireless systems. Its a crowed RF world out there.

Personally I would recommend 5.8 GHz gear for backhauls. Trango works nice for small short hops. It all depends on what you want to accomplish, and how much you can spend."

[TS summed up] "I'm just glad to hear that .11a can work over a distance. I've had so many people tell me it can't, and that none of the radios come with detachable antennas. Just for personal use it would be nice in a rural area with little RF interference. Have to look into it. Then again, 11g is on its way."

—End