3 BH links - How many CMM?

Hi All,

I need to link two places “a to d”, using canopy BH10, with the following configuration:

From a to b: 6 Km
From b to c: 35 Km
From c to d: 10 Km

The 4 point are almost in a straight line.
Which is the right configuration Master/Slave recommended for these applications?
Can I use the RJ11 port for synchronization? Or must I use a CMM in places B and C.
I Would appreaciate any information on this subject.

Thanks in advance.

Put the CMM at the site where B and C are… Set them to masters and have them draw sync from the CMM. Be sure if you are using a CMM2 that you plug one of the radios sync cable into sync port one or it wont work right.

Radios at site A and D are slaves from their respective masters. You can if needed, pass sync from them onto another radio at the site they are at.

Alternatively, you could set B or C to masters, and have one set to generate sync pulse, and then the other sync to rec. signal, timing port and run a sync jumper between them. This would make them sync’d so they work just as if they were sync’d from a GPS source.


You’d use the RJ11 port if you did not want to use a CMM and you’d use the CMM port if you wanted to use the CMM2.

Cabling for the RJ11 (actually its an RJ12)


This is made with the little tab facing down to the ground, and you are looking directly down onto the gold pins, with the entry for the cable jacket facing your chest. Insert the wiring left to right, starting with the wht/org.

Thats about the best explanation I can get right now this early in the AM…

Let me see if i understand this (Sorry, but my english is not very good)

I could set both BH at B as master. Set one of them to Gerate Sync and the other to Rec Sync. Conect them using the RJ12 sync port.
Then at point “C” I can pass the sync Pulse from the BH Slave at “C” (That already sync to BH mster at B) to the BH Master at C using the RJ11 conector. In this case, I can get the three hops synchronized, whitout the CMM. Is this correct?


Hows that?

I put the network switches in as a suggestion. It’s easier to troubleshoot and configure the network if you are at those sites if they do not already have a network switch at that location. Without the switch, you have to take down one portion of the network to plug your laptop into the radio.

The blue lines are the Ethernet connections to the switch.

The dotted red lines are the straight-through RJ-12 sync cable. Make it just like I told you earlier.

Ensure that the backhauls are timed appropriately like I noted

Also ensure that the option for "Frame Timing Pulse Gated is set to Enabled.

Clear as mud?

I should note that this is my understanding of how to do what you want to do.

There may be a caveat in the solution in that you’ll have to use BH’s of a different frequency than the link from B to C, at site C on the link from C to D.

Someone correct me if I am wrong anywhere.

I would engineer the hops in a similar fashion, except I would use CMM’s.

Here is how I would do it using arbitrary frequency bands.

Site A:

- 5.8 GHz BHS

Site B:

- Put a CMM Here

- 5.8 GHz BHM which talks to the BHS at Site A
- 5.2 GHz BHM which will talk to Site C

Site C:

- Put a CMM Here

- 5.2 GHz BHS which talks to the BHM at Site B
- 2.4 GHz BHM which will talk to Site D

Site D:

- 2.4 GHz BHS which talks to the BHM at Site C

You can do this in many different ways, depending on your budget and spectrum availability. Your link distances and location will dictate which frequency bands are the best choice. If the links are pretty much in a straight line, then you may be able to use the same freuquency band at the sites where the CMM’s are, even the same exact channels, assuming the links are ~180 degress offset from each other and that you will definitely be using CMM’s.

If it were me, I wouldn’t even bother with BH10’s.

Trango Atlas 5010’s will cost 30% more, but will give you far better latency, throughput, and interference resistance.

The Atlas’s can operate in 5.2 and 5.7. I would probably run 5.2 on the shorter hops and then 5.7 on the longer hop.

Jerry Richardson wrote:
If it were me, I wouldn't even bother with BH10's.

Trango Atlas 5010's will cost 30% more, but will give you far better latency, throughput, and interference resistance.

The Atlas's can operate in 5.2 and 5.7. I would probably run 5.2 on the shorter hops and then 5.7 on the longer hop.

Hi Jerry,

Are you sure that Trango Atlas is far more better than BH10?
How about their PtMP? is it worth it to try?

I believe rightnow too many WISP using Canopy....maybe its time to think about combination

Can’t speak to the P2MP

For the P2P, the Atlas is an excellent choice. Our main 15mile BH link was with Canopy 5700BH20 (P9) and at 5M down and 2M up it was choking. Latency was increasing every day.

We replaced it with Atlas 5010’s running at 5835 using 33dB PacWireless dishes and we are now seeing peaks of 7M x 3M with no increase in latency. Overall network performance improved immediately.

We have a building to building link (LAN extension) using 5010’s getting 54Mbps aggregate and 2ms latency.

We have a tower to tower link running on 5700BH20 P8 that we will be replacing with Atlas 5010’s running at 5.2GHz.

We are thinking to build new cluster with 5.x AP.

If the PtP technology from Trango crush BH10 technology, I believe the PtPM should be do the same thing also…

I will try to call trango rep tomorrow, and see what they can do to convince me to buy their products.

and btw, why moto didnt re-design their BH10,20? or rightnow they are in the top of making money, so its no time to think for the competitors… :evil:

I seriously doubt that anything is better than the Canopy P2MP technology.

I think that they did not do anything with the BH10 and BH20 because they want you to buy the OFDM product which is better than the Trango but twice the cost.

we just couldn’t see spending 6k when we could get what we needed for 3k.

I agree with using the CMM… Everyone should use CMM’s when you have more than one hop or AP…

The reason I suggested generating sync, was due to the cost factor.

I think one CMM is enough, on site B.

Per Jerry’s suggestion I setup a Trango 5010 link at one site instead of going with 20 Mbps backhauls. The link was a short .25 mile hop but it was solid trees. Right now we’re seeing 36 Mbps and 1-2 ms latency using the standard 5010’s with integrated antennas. I’m sure the connectorized version with 2’ dishes would get the full 54 Mbps.

Another neat thing about the Trango backhauls is that you don’t have to specify a certain uplink/downlink percentage. The radios dynamically allocate bandwidth based on load. This makes it really easy to do redundant diverse links without having to worry about downlink/uplink percentages and traffic flow directions.

Pricing on a pair of 5010s is roughly the same cost as a pair of 20 mbps canopy BH’s.

Are these Trango links 802.11 based? I would hope not but the data throughput values expressed in this thread caught my attention.

amd phreak, Thanks for the explanation. It couldn’t be more clear. I will try exactly this configuration and then I let you Know.