Who is most reliable vendor for outdoor Point-to-Point?

Hi,

I need to set up a *very* reliable outdoor point-to-point link to
bridge a piece of equipment and a network. The distance is not large -
on the order of 200 meters. The equipment should have a temperature
range suitable for outdoor operation, say, down to -20 Celsius.

I'm looking for equipment that is absolutely bullet-proof: something
that will literally run for 10 years without needing a reboot.

Which vendor(s) out there have a reputation for stable, reliable
equipment? Could anyone share their personal experience - good or bad -
with a similar system?

Thank you,

Bartek Muszynski
Vancouver, BC

(E-Mail Removed) wrote:
>I need to set up a *very* reliable outdoor point-to-point link to
>bridge a piece of equipment and a network. The distance is not large -
>on the order of 200 meters. The equipment should have a temperature
>range suitable for outdoor operation, say, down to -20 Celsius.
>
>I'm looking for equipment that is absolutely bullet-proof: something
>that will literally run for 10 years without needing a reboot.

Fiber's going to be about your only option. WiFi isn't nearly that
reliable, and the interference sources moving into your neighborhood 5
years from now will trash your existing wireless network.

Care to share the details of your equipment, network, and reliability
requirements?

> I'm looking for equipment that is absolutely bullet-proof: something
> that will literally run for 10 years without needing a reboot.

You'll probably want to talk to the companies that work in industrial
data collection. The two market leaders are:

http://www.intermec.com/

http://www.symbol.com/

In a previous position I installed both Symbol and Intermec equipment
outside at a ski resort for wireless data applications. Provided you
bought their ruggedized (read: expensive) gear, it worked well.

Keep in mind anything outside is going to need some TLC occasionally,
i.e. to brush off the snow and ICE, clear leaves or what have you.

Cheers,
Geoff Glave
Vancouver, Canada

On 2 Dec 2005 11:28:28 -0800, (E-Mail Removed) wrote:

>I need to set up a *very* reliable outdoor point-to-point link to
>bridge a piece of equipment and a network. The distance is not large -
>on the order of 200 meters. The equipment should have a temperature
>range suitable for outdoor operation, say, down to -20 Celsius.

If you want reliability, the telecom vendors found the method years
ago. Spatial and frequency diversity. Basically, it's two radios, in
two parts of the tower, on different frequencies, with fail-over
protection. If something trashes one frequency, the other is likely
to still be working. If some reflective, diffractive, or absorbent
object gets in the way of one path, the other is highly likely to
still be functional. That also includes separate power sources and
redundant data paths. Redundancy also allows for preventive
maintenance of one radio, while the other continues to shovel traffic.
To insure that things don't deteriorate, drift, or just plain fail,
monitoring is mandatory. That means some kind of SCADA system with a
data logger and threshold alarms to alert the maintenance people that
something is about to blow up.

>I'm looking for equipment that is absolutely bullet-proof: something
>that will literally run for 10 years without needing a reboot.

I forgot to mention that bullet holes in the antennas was a problem
with fiberglass that tended to shatter. Panel antennas were far too
easy for target practice. I suggest spun aluminum dish antennas with
pressurized (and alarmed) Heliax. At least you know when someone has
shot a hole in the antenna.

Methinks your 10 years of uptime is unrealistic for a simple reason.
The error rate in modern DRAM and uP systems is sufficiently high to
insure at least one crash per year (or more). If the inherent soft
error rate doesn't crash the box, cosmic rays will also do the same
thing.
http://en.wikipedia.org/wiki/Soft_error
ECC RAM and redundant multiprocessors are a big improvement for
servers, but have not been used in common wireless equipment. More
commonly, the radios have a totally independent watchdog timer to
verify that nothing has crashed. (Note: software watchdog timers
don't work well). I would not expect anything to stay up for 10
years, but with regular reboots, redundancy, monitoring, and
preventive maintenance, it will last for 10 years.

Incidentally, I have some Breezecom Alvarion AP-10/SA-10 2.4GHz links
running at 3Mbit/sec (1.2Mbits/sec thruput) that have been up since
about 1994 and are working just fine. They have to be remotely reset
on occasion, but have never failed (except when someone plugged the
wrong power supply into one and blew up the protection diode). Biggest
headache are the trees that grew into the line of sight.

>Which vendor(s) out there have a reputation for stable, reliable
>equipment? Could anyone share their personal experience - good or bad -
>with a similar system?

No comment. All I know is the distance and a very unrealistic
reliability figure. No clue on speed, cost limitations, environment,
and topology. How about a better clue as to what you're doing and
what's connected on each end?

--
Jeff Liebermann 150 Felker St #D Santa Cruz CA 95060
831.336.2558 voice
http://www.LearnByDestroying.com AE6KS
http://802.11junk.com Skype: JeffLiebermann
(E-Mail Removed) (E-Mail Removed)

(E-Mail Removed) wrote:

>Hi,
>
>I need to set up a *very* reliable outdoor point-to-point link to
>bridge a piece of equipment and a network. The distance is not large -
>on the order of 200 meters. The equipment should have a temperature
>range suitable for outdoor operation, say, down to -20 Celsius.
>
>I'm looking for equipment that is absolutely bullet-proof: something
>that will literally run for 10 years without needing a reboot.
>
>Which vendor(s) out there have a reputation for stable, reliable
>equipment? Could anyone share their personal experience - good or bad -
>with a similar system?
>
>Thank you,
>
>Bartek Muszynski
>Vancouver, BC
>
>
>
What OS will you use? Certainly not anything from uSoft.

--
Cheers, Bob

[POSTED TO alt.internet.wireless - REPLY ON USENET PLEASE]

In <(E-Mail Removed)> on Sat, 03 Dec 2005 03:52:51
GMT, Jeff Liebermann <(E-Mail Removed)> wrote:

>Methinks your 10 years of uptime is unrealistic for a simple reason.
>The error rate in modern DRAM and uP systems is sufficiently high to
>insure at least one crash per year (or more). If the inherent soft
>error rate doesn't crash the box, cosmic rays will also do the same
>thing.
> http://en.wikipedia.org/wiki/Soft_error

With all due respect to both you and Wikipedia, even commodity
microprocessor-based systems are roughly an order of magnitude better than
that. Cosmic rays are very old news.

--
Best regards, FAQ FOR CINGULAR WIRELESS
John Navas <http://en.wikibooks.org/wiki/Cingular_Wireless_FAQ>

On Sun, 04 Dec 2005 07:42:46 GMT, John Navas
<(E-Mail Removed)> wrote:

>[POSTED TO alt.internet.wireless - REPLY ON USENET PLEASE]
>
>In <(E-Mail Removed)> on Sat, 03 Dec 2005 03:52:51
>GMT, Jeff Liebermann <(E-Mail Removed)> wrote:
>
>>Methinks your 10 years of uptime is unrealistic for a simple reason.
>>The error rate in modern DRAM and uP systems is sufficiently high to
>>insure at least one crash per year (or more). If the inherent soft
>>error rate doesn't crash the box, cosmic rays will also do the same
>>thing.
>> http://en.wikipedia.org/wiki/Soft_error

>With all due respect to both you and Wikipedia, even commodity
>microprocessor-based systems are roughly an order of magnitude better than
>that. Cosmic rays are very old news.

It varies depending on complexity, altitude, and chip density.

http://www.edn.com/article/CA454636.html
A cell phone with one 4-Mbit, low-power memory with an SER of 1000
FITs per megabit will likely have a soft error every 28 years. A
high-end router with 10 Gbits of SRAM and an SER of 600 FITs per
megabit can experience an error every 170 hours. For a router farm
that uses 100 Gbits of memory, a potential networking error
interrupting its proper operation could occur every 17 hours.
Finally, consider a person on an airplane over the Atlantic at
35,000 ft working on a laptop with 256 Mbytes (2 Gbits) of memory.
At this altitude, the SER of 600 FITs per megabit becomes 100,000
FITs per megabit, resulting in a potential error every five hours.
The FIT rate of soft errors is more than 10 times the typical FIT
rate for a hard reliability failure. Soft errors are not the same
concern for cell phones as they can be for systems using a large
amount of memory.

More numbers at the bottom of:
http://europe.elecdesign.com/Article...378/10378.html
and in:
http://www.actel.com/products/rescenter/ser/

I've kept servers up for more than a year. Some servers I've seen
show uptimes of perhaps 2 years. I don't think any device can stay up
without rebooting for 10 years, especially if updates and cleaning are
required.

--
Jeff Liebermann (E-Mail Removed)
150 Felker St #D http://www.LearnByDestroying.com
Santa Cruz CA 95060 http://802.11junk.com
Skype: JeffLiebermann AE6KS 831-336-2558