Wireless Access

Just wondering, if I was to have an AP-274 which has 6 external N-Type connectors for the antenna and I wanted to use only 1 D608 antenna which is a dual band antenna which support 2.4 and 5 GHz, how would I go about connecting it to the AP?

I know that I can connect 2 antenna separately, one for 2.4, one for 5 GHz to the AP-274.

A single D608 connected to an AP-274 is not supported. If you wanted to run unsuported though you would need to attach diplexers to the antenna that would allow two N- connectors of the AP to bridge into a single connector on the antenna. Good ones are very expensive (usually a couple hundred each, noting that most are limited in bandwidth which makes using them on dual band antenna difficult), far more than the cost of a new antenna usually) but regardless using dixplexors will add loss (1-1.5 for the diplexer and another 1-2 for connectors and cabling), and will decrease coverage of the AP (more on the 5GHz than the 2.4GHz usually). Your better option would be to use an AP-277 instead.

Also note that diplexers are NOT supported either, they can introduce noise and cause issues with the signal that would/could likely make any of the higher QAM rates unuseable in the 11ac range (definately a very real risk in cheaper hardware, good diplexers can run $200-400 each). Again, NOT recommended but if you want to try it and possibly turn your 11ac AP into a lower power, likely slower than 11n AP to use a single antenna, you can try it :)

Thank you for the reply. I was thinking about a diplexer, but then the cost of 3 of them per AP is more than having another antenna.

AP-277 with 80°x80° is a bit too wide, so that's why I was thinking to go with AP-274.

60°x60° (D608 antena) would be ideal for 5GHz and actually too wide for 2.4GHz, something like ANT-2314 which is 30°x30° would be better for 2.4GHz, but it's only a 2 connector model, not a 3 connector antenna.

Is Aruba considering making APs which will have dual band external antenna connectors?

Not right now, no. The issue with outdoor APs having diplexed antenna connectors like the indoor Aps is that it limits you in what antennas you can deploy. For mesh, we often need a directional 5Ghz antennas and omni-directional 2.4Ghz antennas, and we couldn't do that with a diplexed solution. For 95% of the customer out there that want a directional client access solution, the 277 is a perfect fit. Most antennas over 7-8dBi don't work real well for client access, as using a 14dBi directional 2.4Ghz antenna won't really buy you much more distance than a 277 will, as most clients have a 400-600m limitation at the PHY level anyway. You might see good SNR at 1/5km with a client, but the client won't be able to talk back to the AP and the distance is too far anyway and the packets time out over the air. 

If you just need the narrow pattern and don't care about distance, the 2314 is a fine solution (albeit that antenna is pretty large, as are any 2.4Ghz 10dBi+ antennas). For a dual band narrow-pattern solution (like what we use in many VHD/LPV solutions), the 5314 and 2314 work fine. 

you can also use the ANT-2x2-2314/5314 on the AP-274 without issue, you just want to put a 50Ohm terminator on the unused 3rd chain connector.

Thanks. I was looking for a narrow antenna for a small stadium seating area in order to achieve sectorization.

As you said, 5314 and 2314 look like the best option. My inital thought was to try and go with 1 antenna only instead of mounting 2 antenna, one for 2.4 and the other for 5GHz next to each other.

Since it's an open area, under the roof, but still exposed to the weather, AP-274 is the only option.