George Hardesty

Apr 092015

Optimization of the link involves trying different settings of channel sizes and power:

  1. Long links:  For links over 10 miles / 22km:  Smaller channel size  20MHz is almost certainly going to work best on a link of this distance.  You should try 20MHz and then compare to 40MHz to compare the throughput with each size.
  2. Short links can use a wider channel size: 40 to 80 MHz, to get more throughput (as long as there is not too much interference).  Experiment with the channel size and see which one gives you the most throughput.
  3. Power level:  Adjust the power to see if you get more throughput by adjusting up and down
Alignment:  Optimize the alignment by making very small changes right and left, up and down and watching the reaction of the throughput.
 Posted by at 10:46 am Mimosa Backhauls Tagged with:  No Responses »
Mar 152015

Seven-Mile Link in Arizona:  Actual throughput (MAC layer):  300-400Mbps:  From small town to tower in remote area:  April 2015

  • Using B5c with 34dBi dishes on both sides
  • A lot of interference from operator’s own APs on one towers (12 APs on remote tower, 4 on the small-town tower).
  • Using 20-40MHz DFS channels
  • Not using RFArmor
  • This is an actual, working link

12km Link Example:

  • Noise floor:  90.49dBm
  • 21km link from a building in the city, out to a suburban or rural location, with one hill or small mountain in the path, but this is not high enough to be in the frenzel zone.
  • To make this 21km link, customer will need B5c with 34dBi dual polarity dish (2FT) on each end.  B5 with its 25dBi antenna gain is not sufficient.
  • Throughput at MAC layer:  200Mbps.  For higher throughput, you would need RFArmor.

Mimosa Backhaul products

 Posted by at 6:08 pm Backhaul links, Mimosa Backhauls Tagged with:  No Responses »
Mar 032015

If you use an antenna that is not 2×2 MIMO (if it only has one connector) you will not get 2×2 MIMO from the Rocket:

If the antenna only has one connector, you will only get one spacial stream rather than two (1×1 rather than 2×2) hence the throughout will be half of the throughput you would get with 2×2 MIMO.

The best antennas for the Ubiquiti Rockets are the 2×2 dual-polarity antennas from Ubiquiti – because:

  • the two connectors for 2×2 MIMO and
  • the rocket snaps right in to the back of the UBNT antennas.
Feb 262015

Six feet is not too long for the LMR-100-equivalent cable that we use for shorter antenna cables.  However, it is right at the threshold at which we would recommend that you consider the thicker cable.    This comparison shows that the expenditure for the thicker cable, which is about 25% higher cost, is proportional to the benefit of lesser signal loss (attenuation).  If you are using small antennas you may need as much gain as possible retained during passage through the cable and it would make good sense to pay the additional 25% for the 200-thickness cable:

CLF-100 coax (quality similar to LMR-100, but better):  Attenuation (signal loss) is 0.39dB per foot:  Over six feet, you would lose 2.34dB
CLF-200 (quality similar to LMR-200, but better):  Attenuation (signal loss) is 0.30dB per foot: Over six feet, you would lose       1.80dB
The difference is 0.54dB.  You may know that addition of an antenna multiplies the power of the WiFi device, such that even a difference of 0.54dB makes a big difference:
3.0dB net antenna gain (after cable loss) =  2.0X power increase for WiFi device
3.5dB net antenna gain (after cable loss) =  2.6X power increase for WiFi device   <- a 25% power increase coming from a 0.5dB net antenna gain in this example.
For a six foot cable VS. ten foot cable, the difference in your cost between using 100 thickness cable VS. 200-thickness would be $1.25.
Therefore your power increase would be roughly proportional to the difference in cost of the cable.
LMR-100 compared to RG316

LMR-100 has lower signal-loss than RG316

 Posted by at 6:46 pm Coax for Antenna Cables Tagged with:  No Responses »
Jan 232015

To whom it may concern,

In my world, I only seem to hear when someone on our team doesn’t live up to our expectations.  I believe it’s important when people go above and beyond that they should be recognized.  Simon Kingsley has done just that.  Our company is in the middle of a development project and at the critical junction.  On this Friday afternoon at 4:00PM EST we needed a very unusual adapter.  When searching online, what we found was 15 to 30 days to deliver from China.  My colleague went to google and your company caught our attention.  We were fortunate enough to get Simon on the phone and he was a tremendous help.  He configured the adapter set to meet our requirements and was able to get your shipping department to run to UPS and drop it off for Saturday delivery.  We were thrilled; the project would not come to a halt.
After the adrenaline and settled we reviewed the order and realized our configuration was wrong.  We immediately called Simon knowing we were at the UPS cut off time.  He went into action and identified the right parts, got the warehouse and shipping people on the phone and was able to get the correct parts out for delivery on Saturday.  A remarkable feat.
He was calm, courteous, patient and projected this “can do” attitude.  Please note, I’m talking about an $8.00 part.  In both cases, the cost of freight was immaterial, we were happy to pay the Saturday delivery premium.  The fact that Simon refused to give in and found a way to make this happen was wonderful.
We congratulate your company for having him as a representative.
I can’t thank everyone enough and you have certainly found a new customer.
Sep 202014
Use a cluster mount which enables you to cluster 3 or 4 Ubiquiti sectoral antennas in an array:  There is an array mount for three (3-Gang Mount) and a 4-gang mount.
We recommend that when you use a cluster mount for sectors, that you use the RF Armor shields to prevent the antennas’ leakage from the back, from interfering with each other – and reduce the noise in general.

To connect multiple antennas to the same Rocket: You can if you use a “power divider” or antenna-combiner (not a coax-splitter):  Please see this page on this subject.

The other solution would be to connect one rocket per antenna:   Feedback from customers indicates that this is configuration is noisy – maybe too noisy, even with the RF Armor shields (which are sold separately from the  array mounts).  Of course, the purpose of the shields is to isolate each antenna and reduce the noise among the antennas.

Ubiquiti Sectoral Antenna Array

Sectoral antenna array on 3-Gang Mount

RF Armor Radome Shield Kit for Ubiquiti 120-degree Sector Antennas

RF Armor Radome Shield Kit for Ubiquiti 120-degree Sector Antennas

RF Armor Radome Shield Kit for Ubiquiti 90-degree Sector Antennas

RF Armor Radome Shield Kit for Ubiquiti 90-degree Sector Antennas

Mar 292014

You have one person on the tower and a second person(s) on the ground. The Rohn pulley attaches to a pole (could be a Gin Pole) near the (current) top of the tower.

The person on the ground hoists the next tower section by pulling a rope through the pulley, until the tower section is all the way at the top, and then the person on the tower, fits that section of tower into place.

Mar 132014

Ubiquiti Aircam and Aircam Dome run on 24-volt POE.

Higher-end cameras including Pan Tilt Zoom (PTZ) cameras, use 48-volt POE.

If you are using Ubiquiti POE switches, you will need a TS-PRO-8 for 48-volt: That is the 8-port version.  The smaller version of Tough Switch with 5-ports only has 24-volt POE.

 Posted by at 6:49 pm IP cameras No Responses »
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