Need LAN connection over several hundred meters - how to do this?

[Curious.George]

Re: Need LAN connection over several hundred meters - how to do this?

seems a bit flawed as all hot people are not infectious .

And folks who are infectious aren't necessarily hot!

[petehall347]

Re: Need LAN connection over several hundred meters - how to do this?

@curious george and others

I'm not prototyping this stuff, it is all off the shelf kit and software. So I can't devise my own way of using a low bandwidth channel to just send the occupancy count

The thermal imaging camera has two channels, video (for facial recognition) and heatmap. Anyway that is working just fine as all the kit is close to the entrance. This could do clever stuff by the way - for example of someone presents with an abnormal temperature, you could use the recorded 'mug-shot' and ask the AI t then find all close contacts who were near to that person before they were symptomatic. But that feature is more for the solution I have for hotels where guests are in the same environment for a week or two.

.

seems a bit flawed as all hot people are not infectious .

[dicky96]

Re: Need LAN connection over several hundred meters - how to do this?

Hi George

And what if they CAN'T access the mains? Yep exactly that

TBH You have come up with a lot of the problems I was already facing!!

The 900MHz solution looks interesting. The lower the frequency the better this could work. I will contact these guys and see what they can suggest

Thanks

[Curious.George]

Re: Need LAN connection over several hundred meters - how to do this?

@curious george and others

I'm not prototyping this stuff, it is all off the shelf kit and software. So I can't devise my own way of using a low bandwidth channel to just send the occupancy count

I only suggested that as a quick/easy way to see if the technology would work for you.

First google link: https://www.esteem.com/horizon-900-main-page/

What bothers me about power line - they never seemed too reliable to me - plus assuming they are drawing power from the mains grid, for sure there are going to be long portable extension cables in use, and powerline adapters like to be directly into the mains sockets.

And what if they CAN'T access the mains? E.g., running the kit off a small genset (or even batteries!) Or, the branch circuit in one spot is entirely different from the one used elsewhere?

I was thinking of using microwave link. That would still be doable if I could get the dishes above the height of the market stalls, but then probably there could be other obstructions such as palm trees - plus how difficult/precise would it be to mount and align the two dishes quickly. Maybe one omni-direction transmitter (hotspot) at the camera end and a directional receiving antenna at the PC end? Sort of a long range WiFi.

I was trying to avoid running a very long cable but that is one way to do it. The cable would have to be laid at the start of the event then rolled up neatly in a reusable manner at the end.

It's not just the hassle of deploying a long cable; what if the cable is damaged while deployed? Are you going to hoist it many feet above the heads of the attendees? Are you going to dig a trench to bury it below their feet? Will you have kit on hand to "fix" the cable if it does become damaged? (e.g., fiber requires special tools and skillset) Will the "light turn red" while the cable is being repaired? How long will that process take (imagine having to walk the length of a cable looking for kinks or cuts!)

It's one thing to run a cable (copper or fiber) out along the ground in your own yard or in a business (where folks have an incentive not to earn the wrath of their employer by carelessly damaging it) but another thing entirely to hope "attendees" will respect your kit.

[dicky96]

Re: Need LAN connection over several hundred meters - how to do this?

@curious george and others

I'm not prototyping this stuff, it is all off the shelf kit and software. So I can't devise my own way of using a low bandwidth channel to just send the occupancy count

The thermal imaging camera has two channels, video (for facial recognition) and heatmap. Anyway that is working just fine as all the kit is close to the entrance. This could do clever stuff by the way - for example of someone presents with an abnormal temperature, you could use the recorded 'mug-shot' and ask the AI t then find all close contacts who were near to that person before they were symptomatic. But that feature is more for the solution I have for hotels where guests are in the same environment for a week or two.

What bothers me about power line - they never seemed too reliable to me - plus assuming they are drawing power from the mains grid, for sure there are going to be long portable extension cables in use, and powerline adapters like to be directly into the mains sockets.

The camera at the exit is 2 mega pixel

Budget - well so far the system is in at around $9000 (USD) so if it costs another $1000 to get the remote camera linked across 200-300m it would be acceptable, though i would hope it was less than that - several hundred dollars possibly.

I was thinking of using microwave link. That would still be doable if I could get the dishes above the height of the market stalls, but then probably there could be other obstructions such as palm trees - plus how difficult/precise would it be to mount and align the two dishes quickly. Maybe one omni-direction transmitter (hotspot) at the camera end and a directional receiving antenna at the PC end? Sort of a long range WiFi.

I was trying to avoid running a very long cable but that is one way to do it. The cable would have to be laid at the start of the event then rolled up neatly in a resuable manner at the end.

[brethin]

Re: Need LAN connection over several hundred meters - how to do this?

Fiber is the way to go.

[diif]

Re: Need LAN connection over several hundred meters - how to do this?

Powerline adapters will only work on the same ring.
You should be able to get 300m using a couple of PoE extenders.

[Curious.George]

Re: Need LAN connection over several hundred meters - how to do this?

The venue occupancy control system I have uses two LAN cameras, one at the entrance and one at the exit. They are connected to a PC at the entrance using a POE switch and the LAN port. The PC shows a 'traffic light' on screen - or can drive external LED lights - and shows the current occupancy.

The problems I need to overcome are as follows:
a. The exit camera is 200-300 meters from the PC at the entrance and I need to connect it via the same LAN as the entrance camera.

b. There are 400 market stores and a lot of people moving around between the entrance and exit.

c. The Exit camera is not in direct line of sight from the entrance (where the PC is located)

d. There may or may not be internet access available at the market. If there is it would be 4G but Let's assume there is not.

e. This is a portable system. It needs to be quick and easy to set up and the actual situation can vary from one venue to another.

So top and bottom of this. How do I do it?

[I have no idea as to your costs, budget, etc.]

As I see it, your problem is that the cameras are high bandwidth devices to the PC. You "need" a hard connection between the PC and camera(s).

But, the INFORMATION that you are managing is really just "how hot is this body" and "how many bodies have gone in/come out".

This is a LOW bandwidth channel.

Imagine locating "smarts" (a PC) at each camera (or thermal imagine sensor). Let each device reduce the data that it observes to something simple: "person in", "person out", "person too hot", etc.

Then, look at how to exchange this information, reliably, over these longer distances. For a wired interface, you could use EIA485 at 1000 ft or more (at 1Mbps; longer for slower... hint!).

For wireless, you could use some of the ~900MHz transceivers and just pass beeps and bops. You could possibly prototype such a system with a couple of "cordless phones" (NOT cell phones) by butchering their keypads, etc.

Remember, you have "smarts" at each end so you can have the PCs encode and decode any signals passed over the interface -- as well as implement an acknowledgement protocol to increase your confidence in the data being exchanged (turn light RED when you lose connection or encounter malicious interference?).

[You have to look at your resources, skillset, timeframe, etc. I'm just trying to encourage you to free your implementation from the "demands" of the camera-PC links!]

[dicky96]

Re: Need LAN connection over several hundred meters - how to do this?

Hmm I never thought of using power line adapters - I am not sure if that would work. It is possible the power is coming from generators as these are outdoor events (but I will ask the guys)

[mayss]

Re: Need LAN connection over several hundred meters - how to do this?

Search for a network through electric cables, LAN adapters. TP-Link TL-PA211 Unboxing and demo AV200 Power line Ethernet adapter.

[dicky96]

Hi guys
Here is a project I have been working on. I am supplying a company who have a license from the government to re-open the open air markets which have been closed due to COVID-19

They have to fulfill certain restrictions to open the markets, we are currently three weeks into an eight week trial.

The main requirements are:

1. The temperature of every person visiting the market is taken.
2. There is a capacity limit of how many people can be in the market at a given time, and it must be observed.
3. Everyone must wear a mask (Actually this is the law anyway, anywhere indoors or outdoors, with heavy personal fines for non compliance).
4. Everyone uses hand gel at the entrance.

My part of this project is 1. and 2.

For 1. I already supplied a mass thermal imaging system, and it's working fine. This can monitor up to 30 people simultaneously moving through a 3 meter wide entrance 'corridor' without stopping to be checked, It can measure core body temperature outdoors within +/- 0.3C as it uses a Black Body temperature reference which compensates for moving air currents etc, and can process 6000 people in 30 minutes. It give alarms for abnormal body temperature above 37.5C, or persons not wearing a mask. Carrying a hot cup of coffee etc will not trigger an alarm as it uses facial recognition and know the difference between a face and a coffee cup. It's working very well.

For 2. They are currently using a manual system counting people in and out with a mobile phone app which gives an occupancy level. This we need to automate. And this is where my question comes in.

This video is the system in use as it stands. My mass thermal imaging and their mobile phone occupancy app

https://www.youtube.com/watch?v=4IfaC8jvfWI

The venue occupancy control system I have uses two LAN cameras, one at the entrance and one at the exit. They are connected to a PC at the entrance using a POE switch and the LAN port. The PC shows a 'traffic light' on screen - or can drive external LED lights - and shows the current occupancy.

When the occupancy reaches 90% the traffic light goes Amber. At 100% it goes Red and you must wait at the entrance until someone leaves the exit.

This is working well at my office. The AI software is also clever enough to know if someone leaves via the entrance or enters via the exit and can still calculate the occupancy correctly.

The cameras on the LAN are 192.168.1.108 and 192.168.1.109
The PC is using ICS (Internet Connection Sharing) and is 192.168.1.1

I've attached a picture which shows the setup as it is. The square camera looking thing on the tripod at the entrance is the Black Body and only needs power.

The problems I need to overcome are as follows:
a. The exit camera is 200-300 meters from the PC at the entrance and I need to connect it via the same LAN as the entrance camera.

b. There are 400 market stores and a lot of people moving around between the entrance and exit.

c. The Exit camera is not in direct line of sight from the entrance (where the PC is located)

d. There may or may not be internet access available at the market. If there is it would be 4G but Let's assume there is not.

e. This is a portable system. It needs to be quick and easy to set up and the actual situation can vary from one venue to another.

So top and bottom of this. How do I do it?

Best regards
Rich