Question Need camera at gate WiFi doesn’t reach

[pitbullmom]

Hello I hope that I’m in the right place with the questions that I’m going to ask I live on a farm and I have Wi-Fi at the house but there are other structures on the farm that do not have Wi-Fi and the Wi-Fi does not reach to my gate which is about a little more than a football field away from the house I would like to have a camera up there so that I can get a notification when somebody comes through the gate instead of just using multiple driveway alarm that just make noise all day I already have the camera I have power at the gate I just don’t know how to extend my Wi-Fi or do this without it costing an arm and a leg I know I’ve been toldI can buy an additional router or something and put that at the gate I’m not real techie I just need some help if you don’t mind

 

[kanewolf]

Do you have AC power at the gate or only batteries and solar? What temperature range do you get in your area ?

What you can do is buy a pair of wireless devices that form a point-to-point bridge. You mount one on the OUTSIDE of the house pointed at the gate and wired with ethernet cable back to your home network. At the gate you have the second unit pointed back at the house. That unit can then connect to a switch and an ethernet wired camera. You would need power and a weatherproof enclosure at the gate.

 

[Solandri]

Just add a directional antenna to your network. One of these in your house in access point mode pointed at your gate should work (pick 2.4 GHz or 5 GHz depending on the camera's requirements). They have a range up to several km used as a pair, but I've gotten devices to connect to a single unit over 100m away.

https://www.amazon.com/Ubiquiti-NanoStation-loco-M2-Wireless/dp/B00HXT8FFI
https://www.amazon.com/Ubiquiti-NanoStation-loco-M5-Wireless/dp/B00HXT8FPS

And adding periods to your writing would help immensely with readability.

 

[Remeca]

I second the directional antenna idea.

 

[kanewolf]

Just add a directional antenna to your network. One of these in your house in access point mode pointed at your gate should work (pick 2.4 GHz or 5 GHz depending on the camera's requirements). They have a range up to several km used as a pair, but I've gotten devices to connect to a single unit over 100m away.

https://www.amazon.com/Ubiquiti-NanoStation-loco-M2-Wireless/dp/B00HXT8FFI
https://www.amazon.com/Ubiquiti-NanoStation-loco-M5-Wireless/dp/B00HXT8FPS

And adding periods to your writing would help immensely with readability.

Those are not directional ANTENNAS . Those are both directional access points. That is a very different animal. A single locoM2 or locoM5 might work. But the camera, if it has built-in WIFI, will be omnidirectional. So you might get a signal to it but not reliably get one back. That is why I recommend spending the extra $50 for a pair of locoAC units. Assuming that power is available.

 

[Solandri]

Those are not directional ANTENNAS . Those are both directional access points. That is a very different animal. A single locoM2 or locoM5 might work. But the camera, if it has built-in WIFI, will be omnidirectional. So you might get a signal to it but not reliably get one back. That is why I recommend spending the extra $50 for a pair of locoAC units. Assuming that power is available.

This misconception crops up every few months.

A directional antenna is directional for both send and receive. That is, it amplifies signals that it sends in the direction it's pointed. But it also amplifies signals that it receives from that same direction (assuming they're at the same frequencies). So having an omnidirectional antenna at one end is fine if the distance is not too large. There is no difference between send and receive signal strength.

For an audio analogy, it's like using a simple cone as a megaphone over your mouth for when you're talking, but also using it over your ear when you're listening. Your voice can be heard much further away in the direction it's pointed when you're talking. But you can also hear much further away in the same direction when listening. Mathematically, the amplification for both receive and send is identical.

 

[kanewolf]

A directional antenna is directional for both send and receive. That is, it amplifies signals that it sends in the direction it's pointed. But it also amplifies signals that it receives from that same direction (assuming they're at the same frequencies). So having an omnidirectional antenna at one end is fine if the distance is not too large. There is no difference between send and receive signal strength.

The radiated signal decreases by the square of the distance. An omnidirectional antenna can't focus the energy it has available in the desired direction so the power going in any specific direction is lower. Then distance comes in. Yes, a locoM2 has a higher gain directional antenna that might pick up the lower radiated signal. The only way to know is to test. Will that lower signal be enough to get sufficient bandwidth for the camera? Again no way to predict. It has to be tested.
You and I will just have to disagree on the implementation.

 

[Solandri]

The radiated signal decreases by the square of the distance. An omnidirectional antenna can't focus the energy it has available in the desired direction so the power going in any specific direction is lower. Then distance comes in.

The transmitted signal (from the perspective of the AP with a directional antenna) also decreases by the distance squared. And since the distance is exactly the same in both directions, the transmitted signal weakens by the exact same ratio as the received signal. So distance cancels out when comparing transmitted vs received signal strength.

If you're using the same antenna for send and receive, then both signals go through the same transformation between circuitry and RF in the air, so the gain (signal amplification) is the same for send and receive.

Say you have two identical omnidirectional wireless APs. You place them a distance x apart.

• AP_A transmits with strength S. It gets received by AP_B with strength S/x^2.
• Likewise, AP_B transmits with strength S, and it gets received by AP_A with strength S/x^2.

Now say you move them apart to distance 10x, and replace the antenna on AP_A with a directional antenna which boosts signal strength 100x.

• AP_A transmits with strength S, which the antenna boosts to 100S. This gets attenuated by distance to AP_B to 1/(10x)^2 = 1/100x^2. The signal AP_B sees is thus strength 100S(1/100x^2) = 100S/100x^2 = S/x^2
• AP_B transmits with strength S, which gets attenuated by distance tp AP_B to S/100x^2. But the antenna at on AP_A boosts received signal strength 100x, to 100(S/100x^2) = S/x^2.

And so putting a directional antenna on only one end results in the same signal strength in both directions.

 

[kanewolf]

And so putting a directional antenna on only one end results in the same signal strength in both directions.

And that will work as long as the SNR is still acceptable. I can't predict how the radiation of a random WIFI camera at an approximate distance will behave. At some distances and some signal quality it will work. Neither you, nor I can accurately predict the behavior in this specific situation. But I will always buy purpose built hardware to give myself the best chances from the start.
Again, I will say, you and I will have to disagree on the implementation.