Antenna question

[BCSteve]

Say my router has three antennae and they are detachable/upgradeable. Does that mean I can put a high gain antenna on the roof and run that to one of my ports and leave the other two alone? Then an outbuilding can connect and so can devices inside the house? Does that mean the outbuilding gets 1/3 the speed and the inside devices get 2/3 the speed?

 

[stevech]

Say my router has three antennae and they are detachable/upgradeable. Does that mean I can put a high gain antenna on the roof and run that to one of my ports and leave the other two alone? Then an outbuilding can connect and so can devices inside the house? Does that mean the outbuilding gets 1/3 the speed and the inside devices get 2/3 the speed?

No, for several reasons...
coax cable attenuation at 2.4GHz is very high. 1-2 ft. of coax max, or use large diameter lower loss coax for perhaps 10 ft.
Outdoor WiFi antennas that work well are integral to a weatherproof enclosure for an access point or bridge. Such as this one, which has a directional antenna built-in
http://www.newegg.com/Product/Produ...yMark=False&IsFeedbackTab=true#scrollFullInfo

you can also find some that have an omni. The key is to avoid use of coax.

Secondly... a three antenna WiFi device uses MIMO. Making one antenna dissimilar in pattern and location is contrary to MIMO.

Best to use some form of outdoor packaged access point (for service to outside devices) or bridge (to join a WiFi network received outside because inside it would be too weak).

To bring WiFi to an outbuilding, use a pair of the bridge devices as above, or from some similar vendors.

OR- if the AC power wiring to the outbuilding comes from the same AC breaker box as the main building, you might get IP on Powerline to work. See the section in this forum on PowerLine and MoCA replacements for cat5 cable. (Of course, a buried cat5 cable is best).

 

[bonsai]

Say my router has three antennae and they are detachable/upgradeable. Does that mean I can put a high gain antenna on the roof and run that to one of my ports and leave the other two alone? Then an outbuilding can connect and so can devices inside the house? Does that mean the outbuilding gets 1/3 the speed and the inside devices get 2/3 the speed?

This can't be generally answered:
I can at least say, that there are some MIMO chipsets in the market (f.e Ralink), where one antenna is the "master" and the others are MIMO slaves. With these chipsets you can only establish a connection via the "master" antenna and establishing a connection via the slaves is not possible. They only serve for increasing the throughput.

Some chipsets (f.e.Metalink) transmit their 11B beacon only via one antenna. As long as being in mixed BGN mixed mode you won't see the SSID on the other antennas.

Broadcom also tranmits the 11B beacon only via one antenna, but is at least able switch the beacon to the other antennas (one at a time). The problem is, that it uses an intelligent algorithm which selects the beacon antenna with the lowest noise floor, means it can stay for long periods of time on the same antenna, and the solution is not reliable.

b

 

[BCSteve]

Thanks!

stevech....think you can help me find an Omni that would be suitable? And am I right in saying I'd put an Omni version on the house and directionals on each of the outbuildings?

Now that's just for making that link. So am I correct in saying I also need another router on each end as well?

So in the house: internet comes in the wall, goes to utility's modem. Modem plugs into the WAN port on ROUTER_A. ROUTER_A, for example, has a wired PC on one LAN port, a half dozen wireless devices on SSID_A, and OMNI_AP on another LAN port. OMNI_AP is physically situated on the roof (or wherever). I expect that all that will be on subnet A

In an outbuilding: DIRECTIONAL_AP is on its roof with some CAT5 going to ROUTER_B's WAN port, which broadcasts SSID_B and has whatever devices it has. I expect all this to be on subnet B (along with whatever may be on ROUTER_B's LAN ports)


Are "B" devices separate from "A" devices in terms of subnet then? Although, I guess all someone has to do is plug a device into the DIRECTIONAL_AP's cable and they're magically on Subnet A?

Anyway, I think I'm understanding the antenna side of it better at least.

 

[BCSteve]

Or do I have it wrong and what I'd need are a directional for each outbuilding and MULTIPLE directionals at the house (one for each outbuilding)? Then have each of those AP's go into the router on its own port? That is far less scalable than what I had in mind... which is to have them all poing to one Omni AP.

 

[Razor512]

A friend of mine Who lives in a larger and more rural land area, uses a WNDR3700 with 2 u.fl to rp-sma adapters going from the 2.4GHz adapter, to 2 outdoor antennas, to shorten the amount of coax needed, he mounted the router on a wall and ran the wires through the wall with the antennas mounted outside.

For me, a single high end router is enough to cover the whole house (houses in NY are not very large)

If you can get your router as close as possible to where the antennas will be placed, you may be able to get away with 2-3 feet of coax.

 

[BCSteve]

thanks, I think I've got it figured. I'm just going to get an Omni outdoor AP and multiple directional outdoor bridges from Engenius. Seems tailor made for this scenario.

 

[PrivateJoker]

thanks, I think I've got it figured. I'm just going to get an Omni outdoor AP and multiple directional outdoor bridges from Engenius. Seems tailor made for this scenario.

That'll certainly work, but if you're kicking around 3-stream omni as your main AP I did a little research the other day and posted in this thread (post 4) one particular antenna I found that will work w/ Asus 3-stream APs w/ external antenna connectors.

That said, Engenius and Ubiquiti make great all in one outdoor safe enclosures w/ a variety of antennas. Also there are many kinds of "directional" antenna types (panel, yagi, etc) with their pros and cons. L-com is a good antenna vendor/resource, TerraWave too - if you just want to do some reading. But this was really more for just reference, I think that at least starting off with the AP/antenna outdoor combo unit is the best way to start off, IMHO.

 

[sfx2000]

Say my router has three antennae and they are detachable/upgradeable. Does that mean I can put a high gain antenna on the roof and run that to one of my ports and leave the other two alone? Then an outbuilding can connect and so can devices inside the house? Does that mean the outbuilding gets 1/3 the speed and the inside devices get 2/3 the speed?

No - leave them alone - the Antennae were designed with a link budget that the OEM can meet - changing things, this means you're on your own.

 

[stevech]

thanks, I think I've got it figured. I'm just going to get an Omni outdoor AP and multiple directional outdoor bridges from Engenius. Seems tailor made for this scenario.

that's it. That's why I recommended, above, outdoor weatherproof APs or bridges such as Engenius, no coax. Long cat5 cable

 

[BCSteve]

Yep, that's why I'm doing it Thanks. (sorry, I guess I didn't give credit where it was due... but yes, your post is what had me looking at the Engenius)