What range for NSM5 to NSM5 or Bullet Mhp5

[garymansperger]

If I use a NSM5 as AP to other NSM5 what range should I expect? (for 100% solid connection)

Also, if I use a Bullet HP M5 with 9 or 12 bd omni as AP and NSM5s as client?

I am not looking for the max that they will work but the max that they will work with no problems.

[george]

Not trying to be difficult, but there are a number of skill sets you have to cultivate as a WISP. First point is remembering there is no such thing as 100% reliable.

Next is using a simple SOM calculator http://www.terabeam.com/support/calculations/som.php#calc (http://www.terabeam.com/support/calculations/som.php#calc), then you have to develop a decent skill set in Radio Mobile http://www.cplus.org/rmw/english1.html. These are absolute must-haves.

For example, plug in the appropriate numbers into the SOM calculator and you will get decent answers. Never ask someone to run the numbers for you, their environment may have little to do with yours. Play with the fade margin you need through your own experience. For example, we try never to get a connection below -70 as that leaves us room for the noise floor to rise over time...

If you would like some assistance, ping me by IM and I'm happy to help. When I was learning a number of people helped me and still continue to this day.

George

[garymansperger]

OK George,
From the NS5M data sheet, I am not absolutly sure what numbers to use, but I put in:
Freq 5800, Rx/Tx antenna 14, Rx/Tx calble loss 0, Tx power 22, Rx Sensitivity -73 and distance 2 miles.
This give me a margin of 5.1dB.
Is this a reliable number? (or what number is reliable?)
I have selected numbers for the input that are for max speed (a mode) both Tx and Rx.
I do not see what numbers should be used in "n" mode.

[george]

I like your numbers. Particularly on a short link like you have there. I really like the simple SOM calculator, it lets you play 'what if' and gives you a target number when you go to install your radios.

As you indicated, the numbers predict you have 5 dB to play with before the radios have to step down to a lower modulation, so in fact you have a lot of room before you lose the link entirely.

The power output goes up to 27 at 24Mbits, and the sensitivity increases to -83 so at that point you have approx 20dB of headroom which is great. I would expect in the order of 18Mbits of data throughput on a 20MHz channel at 24Mbits air rate.

The longer the link, the more margin is appropriate.

Provided there are no trees in the way, your link should work very well.

If you get GPS coordinates for both ends, plug them into Radio Mobile (free download) it will let you review your path, and export the path to Google Earth. If you haven't used this its very slick. We recently got 1 arc second data for our area and its improved the predictability enormously.

[drwho17]

Woh, a -70 and I thought I was strict insisting on a target of -75, minimum of -80.

[george]

Woh, a -70 and I thought I was strict insisting on a target of -75, minimum of -80.

I have spent years being regarded as a prick over standards. Comes from a mainframe background where we delivered no matter what. No excuses accepted.

We would much rather give a customer away than deliver crappy service. We often get them back... I often get "I really want this customer, what can we do?"

Every time I'm "nice", it comes back to bite me on the bum.

Better not to be nice, just to be professional and get the job done right...

George

[rconaway]

We have a small WISP location in Southern Arizona that has a Powerstation 5 with external 12dBi antenna. Our longest link is about 2 miles at about -78 to NS5's. We did turn the power up to 24dBm on everybody though to get to 100% CCQ. I know this isn't the M's but it gives you some reference as to what to expect. However, I agree with the -70 as being a good standard.