Connecting an external antenna

[Scooterit]

I need to connect a wireless router to a distant AP and need to boost the signal and lower the noise. A Yagi directional antenna should work.

My question how to connect this antenna to the router. I know to use the Coax connections. But the router has 2 connections and the antenna's that I can find online have just one connector...

What to do?

 

[stevech]

Use one of these integral bridge or access point, with integral 10-14dBi antenna
http://www.newegg.com/Product/Produ...&Description=engenious+outdor&N=-1&isNodeId=1

Instead of lossy coax and a yagi, esp. if the coax is more than a very few inches long.

 

[sfx2000]

I need to connect a wireless router to a distant AP and need to boost the signal and lower the noise. A Yagi directional antenna should work.

My question how to connect this antenna to the router. I know to use the Coax connections. But the router has 2 connections and the antenna's that I can find online have just one connector...

What to do?

Need to use both (or more) antennas...

Adding a higher gain antenna boosts both the signal and the noise, so perhaps consider alternate locations/channels if you're trying to light up a distant corner...

 

[stevech]

Adding a higher gain antenna will increase the transmitted and received signals' strength. It will not increase the noise.
It will increase the received interference (all types) and you might consider that to be noise. An "amp'd" 802.11 device would have a transmitter amplifier; it may have a receiving amplifier. The latter is a problem. An inexpensive one adds a lot of noise. So much so that often it has a negative benefit in amp'd products. There are "low noise amplifiers" (LNAs). A truly good LNA is too expensive for consumer hardware.

Engineering-wise, the jargon is
SNR - Signal to noise ratio, where noise is largely within the receiver's circuitry
SINR - Signal and interference to noise ratio. The interference can be other weak 802.11 signals (coherent) or non-802.11 signals like baby monitors.

Ideally, the 802.11 "listen-before-transmitting" (CSMA/CA) prevents colliding transmissions, but it is far from perfect.

 

[azazel1024]

In general higher gain antennas are likely to reduce interference, as they are directional to a small area, instead of receiving interference which might be close by, but not in the direction of the gain from the high gain antenna.

At any rate, you'll need to hook up two antennas to the router.

As for coax length, it depends on the type and length. Generally if you are only talking a meter of coax, the signal loss is pretty low on 2.4GHz. Again, it depends, but you are looking at ~2-3dB of signal loss per meter on 2.4GHz...depending on the type of coax (but the kind you often see for RP-SMA and SMA extensions is ~2-3dB per meter). Its double that for 5GHz.

I can personally vouch for 2dB for the setup I have (2.4GHz) between testing with my 1m extensions on my antennas versus the antennas directly connected to my router.

So a short length isn't a problem. Its when you are running several meters that there is an issue.

 

[stevech]

In general higher gain antennas are likely to reduce interference, as they are directional to a small area, instead of receiving interference which might be close by, but not in the direction of the gain from the high gain antenna.
.

A higher gain omni-directional antenna, like the common 9dBi, do increase interference because they are not directional horizontally. They see 360 degrees on the compass. They are directional vertically, say, 20 degrees (up/down). In urban settings, the interfering neighbors are in the vertical zone (unless the antenna is very elevated), and are in horizontal zone.

A 3dBi gain omni might have a vertical pattern (beamwidth) of 60 degrees or so. A squished spheroid.

 

[azazel1024]

He is asking about a directional antenna though, which will generally reduce interference.

In a home setting, if you have the access points on different floors, a higher gain omnidirectional will reduce interference from your other devices/access points, at least if you have overlapping channels since there will be vertical seperation.

 

[Scooterit]

Need to use both (or more) antennas...

Adding a higher gain antenna boosts both the signal and the noise, so perhaps consider alternate locations/channels if you're trying to light up a distant corner...

Not if you are using a DIRECTIONAL ANTENNA.

I know how antenna's work, my call sign is KJ6ETL...

 

[Scooterit]

A higher gain omni-directional antenna, like the common 9dBi, do increase interference because they are not directional horizontally. They see 360 degrees on the compass. They are directional vertically, say, 20 degrees (up/down). In urban settings, the interfering neighbors are in the vertical zone (unless the antenna is very elevated), and are in horizontal zone.

A 3dBi gain omni might have a vertical pattern (beamwidth) of 60 degrees or so. A squished spheroid.

J need to reach a distant AP for Load balancing.

 

[stevech]

J need to reach a distant AP for Load balancing.

Load balancing... not an RF issue. Most client devices do not choose Best AP based on signal strength. Some do, intermittently. IEEE 802.11 does not define a method.

The only sure way is to use a different SSID on each AP or WiFi router's built-in AP. Then the user must choose as they move about.

 

[Scooterit]

Load balancing... not an RF issue. Most client devices do not choose Best AP based on signal strength. Some do, intermittently. IEEE 802.11 does not define a method.

The only sure way is to use a different SSID on each AP or WiFi router's built-in AP. Then the user must choose as they move about.

Not using the router as an AP I have a UniFi Pro set on a different channel than the remote AP I want to connect to.

 

[stevech]

Not using the router as an AP I have a UniFi Pro set on a different channel than the remote AP I want to connect to.

What about the choice of SSIDs? If same on all APs, many/most clients will choose first-heard during a scan and, as you move nearer a "better" AP, the client is likely to not select it automatically. Very few do.

 

[Scooterit]

You can select and lock down on the AP you want to connect to.

 

[roldogg]

With all of this antenna talk, I want to get a higher/stronger range from my router. I see omnidirectional and directional, ad you have mrntioned, but since my router has 4 antennas, is it possible/beneficial to change just one of the antennas or do they all need to be the same? Years ago, Linksys made a router that came with a directional antenna on it along with the regular antennas. I wonder what happened to that? Also, since it sounds like you guys know a lot about antennas, my girlfriend's dad just bought 500 acres of land that used to belong to some people who would offer hunting leases, $2000 for a weekend hunt for example, and as he was building a house out there, he had something installed in the house which provided a cell phone signal. Where he built the house was in a dead spot. So, if you need to use your cell phone, you can walk closer to this thing, and it provides a signal. Do you have any idea what this thing might be or what something like this costs? Reason being, where my office is, I only get 1 bar and sometimes a voice mail will pop up, but my phone never rung. I could use something like this, but I don't want to ask him what he bought and how much it costs because I don't want him to think I'm being nosey.

 

[azazel1024]

http://en.wikipedia.org/wiki/Picocell

That is what your father had.

Talk to your teleco about one, but if it is work related, unlikely unless your company gets one (which they probably won't for personal use).

For mixing and matching antennas, you can, but it also can cause problems. Especially directional and omni mixed in. With MIMO/802.11n and 802.11ac you can't really mix and match the different spatial streams if they are at vastly different signal strengths.

To the best of my knowledge it'll only use the highest order modulation supported by the weakest spatial stream.

So you might be able to increase coverage/range by mixing in different omni antennas, or throwing in a directional or two (or several), but you are likely to significantly reduce the speed at which you can connect to the access point.

If you need directional coverage, use just directional antennas, if you need omni coverage, get omni antennas. If you need both, then you really need two access points.

 

[Scooterit]

With all of this antenna talk, I want to get a higher/stronger range from my router. I see omnidirectional and directional, ad you have mrntioned, but since my router has 4 antennas, is it possible/beneficial to change just one of the antennas or do they all need to be the same? Years ago, Linksys made a router that came with a directional antenna on it along with the regular antennas. I wonder what happened to that? Also, since it sounds like you guys know a lot about antennas, my girlfriend's dad just bought 500 acres of land that used to belong to some people who would offer hunting leases, $2000 for a weekend hunt for example, and as he was building a house out there, he had something installed in the house which provided a cell phone signal. Where he built the house was in a dead spot. So, if you need to use your cell phone, you can walk closer to this thing, and it provides a signal. Do you have any idea what this thing might be or what something like this costs? Reason being, where my office is, I only get 1 bar and sometimes a voice mail will pop up, but my phone never rung. I could use something like this, but I don't want to ask him what he bought and how much it costs because I don't want him to think I'm being nosey.

To improve the cellphone reception you might want to check out Wilson Cell Phone Boosters. Microcell devices require a good internet connection and only work with up to 4 cellphone numbers that have been registered with the microcell. The Boosters will receive the weak signal with a directional antenna pointing at the distant cellphone tower and rebroadcast the signal locally.

 

[roldogg]

http://en.wikipedia.org/wiki/Picocell

That is what your father had.

Talk to your teleco about one, but if it is work related, unlikely unless your company gets one (which they probably won't for personal use).

For mixing and matching antennas, you can, but it also can cause problems. Especially directional and omni mixed in. With MIMO/802.11n and 802.11ac you can't really mix and match the different spatial streams if they are at vastly different signal strengths.

To the best of my knowledge it'll only use the highest order modulation supported by the weakest spatial stream.

So you might be able to increase coverage/range by mixing in different omni antennas, or throwing in a directional or two (or several), but you are likely to significantly reduce the speed at which you can connect to the access point.

If you need directional coverage, use just directional antennas, if you need omni coverage, get omni antennas. If you need both, then you really need two access points.

Thanks for the info. It would be work related since I own the company.