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<p>Yup, Richard is using them successfully. Here's an email he sent me yesterday:</p>
<p></p>
<p>Hi Dave,</p>
<p></p>
<p>We have two pairs of MaxStream's XPress Ethernet Bridges in the field, </p>
<p>and both pairs have been trouble-free for us. Neither of the links </p>
<p>are line-of-sight -- one link goes through ~850 feet of vines and </p>
<p>trees using 6 dBi yagis, and the other link uses 9 dBi yagis on a </p>
<p>~2,900 foot shot with two rows of trees and a grain silo in the way.</p>
<p></p>
<p>I don't think you can beat these things in simple point-to-point </p>
<p>applications without dumping a lot of money into FreeWave's 900 MHz </p>
<p>Ethernet radios. However, unlike FreeWave's stuff, you can't manage </p>
<p>the radios remotely -- you only get a row of LEDs and some DIP </p>
<p>switches on the XPress's case for configuring it and getting its link </p>
<p>quality.</p>
<p></p>
<p>(For what it's worth, the MaxStream XPress Ethernet Bridges appear to </p>
<p>be rebranded AvaLAN AW900i (indoor) and AW900x (outdoor) radios. The </p>
<p>AvaLANs are generally less expensive than the MaxStreams.)</p>
<p></p>
<p>We also have three pairs of 9XStream radios (19200 bps RS-232 serial) </p>
<p>connecting REF TEK 72A-07s w/ RT422 serial boards to computers. I'm </p>
<p>not as happy with the 9XStreams as I was in SLC. Getting them working </p>
<p>reliably in the field with the REF TEKs took months of fiddling with </p>
<p>radio settings. I'm still not sure if the settings are even close to </p>
<p>optimal -- we got it to "good enough" and called it a day.</p>
<p></p>
<p>We also discovered that if the devices you're connecting to the </p>
<p>9XStreams don't support RTS/CTS flow control, you're doomed to </p>
<p>failure. The radios have *very* small buffers for incoming and </p>
<p>outgoing data, so if your devices don't do flow control, they quickly </p>
<p>overflow those buffers and start sending and receiving nothing but </p>
<p>garbage. (Guess how I found out that the serial port on a Guralp 6TD </p>
<p>doesn't do hardware flow control...)</p>
<p></p>
<p>Richard</p>
<p></p>
<p>-- </p>
<p>Richard Godbee, Unix Systems Administrator</p>
<p>Department of Geosciences, Virginia Tech</p>
<p>4044 Derring Hall (0420), Blacksburg, VA 24061</p>
<p>rwg@vt.edu / +1.540.231.7002 / +1.540.231.3386 (FAX)</p>
<p></p>
<p></p>
<p></p>
<p>On Friday 31 October 2008 09:14 am, David S. Croker wrote:</p>
<p>> Hi Dave,</p>
<p>></p>
<p>> Timely question for us too. We have an application for just such a</p>
<p>> short hop "WiFi" link (across a parking lot). We were thinking about</p>
<p>> using off-the-shelf wireless routers, but maybe we'll have to rethink</p>
<p>> things after your experience.</p>
<p>></p>
<p>> From the NetOpsII meeting, I remember Richard Godbee from Virginia</p>
<p>> Tech saying he was using the Maxstream radios with good</p>
<p>> results. Don't know the model numbers or any specs. I seem to</p>
<p>> recall he was using it for cross-campus connections, but I can't be</p>
<p>> sure. It looks like Maxstream was bought by Digi. Those products</p>
<p>> look to have pretty good price to performance value and might be just</p>
<p>> right for your application, but I have no experience with them.</p>
<p>></p>
<p>> A couple other companies to check out are Afar and Eion (who recently</p>
<p>> bought WiLan). I forget who I talked to who uses Afar products, but</p>
<p>> I know Berkeley uses WiLan products (although it seems like they are</p>
<p>> moving towards Freewave down in Parkfield). Afar touts Mesh</p>
<p>> networking if that helps.</p>
<p>></p>
<p>> If you get something working that you like, let us know. Like I</p>
<p>> said, we have an application for it too.</p>
<p>></p>
<p>> Dave Croker</p>
<p>></p>
<p>> At 03:16 PM 10/29/2008, Dave Drobeck wrote:</p>
<p>> >Hi All,</p>
<p>> >We recently deployed some dataloggers using consumer grade WiFi links. </p>
<p>> > They proved to be very poor performers for continuous telemetry. We're</p>
<p>> > looking for other ideas. We could certainly use Freewave, Trango,</p>
<p>> > Canopy, etc, but these are all way over-kill for the applications (a few</p>
<p>> > hundred feet) and costly. What other ethernet bridges have folks used</p>
<p>> > (Maxstream?) that have proven reliable?</p>
<p>> >Dave Drobeck</p>
<p>> >University of utah</p>
<p>> >_______________________________________________</p>
<p>> >ANSS-netops mailing list</p>
<p>> >ANSS-netops@geohazards.usgs.gov</p>
<p>> >https://geohazards.usgs.gov/mailman/listinfo/anss-netops</p>
<p>></p>
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