Would I really need a backhaul?

I am an end user trying to get broadband to my remote home (tired of satellite lag). I need to establish a 17 mile link and have been pointed to the canopy backhauls. But my question is, would it be possible to make it with a AP -> SM with large dishes on them? Would SM->SM work? It would be a point to point link so EIRP wouldn’t be an issue ( I don’t think). Mostly, I am trying to save money here. I am planning on using 5.7Ghz due to Fresnel issues.


No, you do not need to run BH’s. You can run AP to SM, that would be fine. It just depends on how much bandwidth you are trying to get. An AP to SM would more than cover the speed of ADSL or Cable. SM to SM will not work. It does not operate like 802.11b, where you can put them into ADHOC mode.

you said you will use 5.7?? will i guess 5.7Ghz band is at 10miles max according to Moto…

if its about 13miles-15miles, then you can try the 2.4Ghz to atleast save, or if not, the 900Mhz one.

Backhaul is nice, but a little bit expensive. =)

Okay, so if a AP <-> SM would work is there any reason why I couldn’t put the AP on a dish. Like I said this is PtP link but it is 17mi. so I would need the dish. The physical mounting looks the same on the AP as is on the SM so would it mount to a SM dish without a problem?


Yes, you can mount the 5.7 AP on a dish also. You should be able to get over 30 miles with a clear RF LOS.

EIRP is still an issue, which is why you need to use 5.7 vs 5.2GHz. The dish increases the EIRP above the maximum permitted by the FCC for 5.2.

Isn’t mounting the AP on a dish illegal?

No, it’s not illegal, but it is limted from a functional standpoint: you can still do point-to-multipoint, but the multipoints have to be in a straight line.

The FCC is only concerned about EIRP levels in specific frequency bands. The FCC regulations often specify EIRP variations permitted depending on the directionality of the antenna, but generally the more focused the beam, the greater the allowed EIRP.

I would guess that the FCC would consider an AP-SM pair with reflectors no different than a pair of BHs with reflectors; they’re both narrow-beam and effectivly point-to-point.