We want to establish a point to point link with a distance of 18 miles. The NanoBridge specs show a range of 30+ KM (18.6 miles) which put these at the edge of published range. Now the Rocket M3/RocketDish shows a range of 50+ KM (30 miles) which seems to be a much better choice although higher priced. Anyone have experience with the NanoBridge at distances greater than 18 miles? Would we be okay with the NanoBridge or should we go with the Rocket M3/RocketDish?
Comments on which way to go would be appreciated.
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Bob, W7REJ
Comments on which way to go would be appreciated.
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Bob, W7REJ
Hi Bob,
I run an M3 NanoBridge from my QTH up to an M3 Rocket/Sector node (AM-3G18-120) backbone node on Mt Palomar, 6000'+ and about 21 miles east of me. I consistently achieve 100 LQ and NLQ with 30-40 Mbps on the Mesh Status report.
Between backbone nodes I run the Rocket M3/RocketDish combo and achieve 40 to 50 Mbp out to a maximum distance between nodes of 48.8 miles.
In summary, I wouldn't spend the extra money, but in the end, it's all about your data throughput requirement.
BTW, we do not support the M365.
Andre, K6AH
Using the specs for each
I ran the data through the UBNT Airlink app and this is what it gave me, of course this is hypothetical.
The fresnel zone was unobstructed.
NanoBridge M3 at both ends, Power 28 dBm, Gain, 19 dBi, Actual EIRP 47dBm but Airlink only allowed 44 so that's what I used:
- 5 MHz the total capacity is 21.13 Mbps
- 10 MHz the total capacity is 38.02 Mbps
- 20 MHz the total capacity is 67.60 Mbps
Rocket M3/RocketDish at both ends, Power 28 dBm, Gain, 26 dBi, actual EIRP 54dBm but AirLink anly allowed 51 so that's what I used:- 5 MHz Channel Width: Total capacity (throughput): 21.13 MHz
- 10 MHz Channel Width: Total capacity (throughput): 42.25 MHz
- 20 MHz Channel Width: Total capacity (throughput): 84.50 MHz
The county has the money to spend either way and they are paying for it. Based on these hypothetical numbers and your real world results I believe your correct in going with the NanoBridge and saving the money.Just a tidbit on a setup I have at my house. We installed a Rocket M2 with a 120* sector antenna on Mt Lemmon about 8500 or so feet. It is pointed centered in my direction with the intent to cover the Tucson Metro valley floor. I'm south of Tucson by about 20 miles and my distance from this node is over 33 miles. Using a bullet and a 21 db panel antenna pointed to this node I am able to get LQ and NLQ at 100%. However these numbers are not consistent and will at times drop way down and bounce al around. I did not even expect this since I know I'm at the fringe and I know there are fresnel issues at my end with the node barely clearing my neighbor's roof and my signal level is about 10 db or less above the noise. Still I'm amazed at this.
Hope you have a great thanksgiving.
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Bob, W7REJ
There are two other factors you'll probably want to consider:
1) The higher the gain, the harder it is to peak the antennas. In your scenario, the NanoBridge will be much easier to aim.
2) In San Diego County I periodically see thermal inversion conditions which refract the signal as it's traveling up to the mountain-top. Under these conditions, narrow beamwidths tend to stray from their targets. You see this in the SNR archive charts. A NanoBridge's broader beamwidth would do better under these conditions, but you will need to be clever enough to compensate for this during installation. IIRC the refraction is in the upward direction... so point it a little low to start with. This could also account for what you're seeing from Mt Lemon.
Andre, K6AH
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Bob, W7REJ
What I meant to say was the higher the antenna gain, the harder it is to aim (higher gain antennas have narrower beamwidths). I wasn't referring to the RF power setting... although re-reading it now, I see how poorly I wrote it.
Andre
Joe AE6XE