Backhaul radio's between MAPs

[mvlaardingerbroek]

For a meshing solutions I've been breaking my head over a question and I can't find the answer via searching, so I'm hoping someone here can tell me the answer.

Assumptions, correct me if I assumed wrong:

• 5 GHz is used for backhaul for less risk of interference
• In a mesh, 1 radio is used for backhaul
• If there is a second 5 GHz radio, like on the 9124, it can be used for client access, not for extra backup up or downstream (this is the big one)

If I combine these assumptions, that leads me to conclude all MAPs that trace their parentage to the same RAP use the same channel, no matter how many hops away they are. This also means that it's not possible to connect a patch antenna on radio 1, pointing to the RAP and then connect an omni antenna on radio 2 to connect to the next downstream MAP.

I would really love it, if the second radio can also be used to mesh. Else it's just going to be 1 big repeater network which is dividing the speed in half for every hop. If it is possible to make the second radio also participate in mesh, I would really like to know how.

[Scott Fella]

Keep in mind that the 2nd radio is a micro radio and will not provide or might not provide you with adequate coverage, but that is for your to determine. 5GHz band does have less interference, but also has more attenuation than 2.4GHz.  MESH is not a repeater network, but you also have to limit your hops to max 2 or 3.  Indoor vs outdoor MESH is very different and the fact you also want client access can be an issues depending on how many clients.

[mvlaardingerbroek]

It's for outdoor, there's good line of sight. Client access for now is not an issue. All we need is some PLCs on moving constructions to be able to send their data, sadly they only have wired connections. Which is why we have 9124's with their 1Gbps ports as access ports.

I know the second 5 GHz can be used for client access, but can it be used for extra backhaul or not?

[Scott Fella]

That can't be used for backhaul.  Only the main radios can be used for that.  As long as you have line of site, you have to figure out first if you want to use the 2.4GHz or the 5GHz for backahul and then also determine if where you can mount them still provides good line-of site and or distance.

[mvlaardingerbroek]

So if the RAP is at channel 100, and only 1 radio per AP can be used, even at 3 hops away, that MAP is still at channel 100 for the backhaul? as I don't see that one radio switching channels to talk upstream to the RAP, and downstream on a different channel to another MAP.

[Rich R · Accepted solution]

Correct

[Scott Fella]

Keep in mind, if you use DFS channels, that can force a the RAP to use a different channel and then all the other MAP's will need to run a discovery to find the RAP or adjacent MAP.