networking idea using cellphones, ideas appreciated...

[MrHaydenJr]

So recently I went to a trade show as a vendor, and while buying a nice high powered router covered everything within our booth, we also had a mobile transportation robot, he's a neat little load carrying roomba essentially.... \

the problems lies in the fact that I need wireless control of him, incase he gets lost or some gashat wants to keep stepping in front of him, so then I can take over and drive away or send him on another route. For the show I put him on a small LAN network using one of the small USB powered routers and hid it within his "shell", worked great here at the shop with plenty of diastance between us, but the problem arose when at the trade show with 100's of visitors and probably 40-50 wireless networks created all around us, I basically had to be right beside the thing to be able to establish a connection for control.... kinda defeats the purpose of wireless... 

 

i think the problem i had was that all of those networks sharing the 3 main 2.4ghz lanes (5ghz wasnt any better but I forced 2.4 as I was trying to get distance) were disturbing my singal causing inteference, especially walking around the building...

 

so this got me thinking, is their a way to use two cell phones to create a point-to-point LAN using the cell phone (LTE) signals as the transmission medium... any ideas if this has been done? any documentation i can read up on, maybe some of the cellphone pros can guide me a bit here but i think it definetly show merit...

 

heres my thought's:

 

both devices send and recieve data from the phone, so why couldnt they broadcast to one another directly? internet isnt really needed from either device... just need to access an IP device connected to one phone from the other... if both phones had service im sure i could whip up a VPN and do it that way, but im think more like two old cell phones... im pretty networking savy but never looked into LTE, im sure its similar... im also interested if using the cell phones radio transmission could dramatically increase the range of the "LAN" as well seeing as how my phone talks to a cell tower thats miles away... 

  

[Remarkable_Day]

Although I am not an LTE guru, I don't believe there is a way to connect two LTE devices together in a P2P configuration, they were never designed to talk like that.

https://www.quora.com/Can-you-connect-2-phones-directly-by-LTE

 

Have you had a look at something like LoRaWAN? I am not sure on your bandwidth requirements, if it is just simple instruction been transmitted e.g. 'Go to this coordinate'. For example video over LoRa will never work, but if the requirement is low, you could setup a small private network with a raspberry PI as a LoRa gateway. The range can be up to several miles, however bit rate is measured in bps, let alone kbps.

 

Another option but carrying significant costs could be to upgrade all equipment to the wifi 6E standard - this will be virtually empty at the moment, and even as it fills in the future, there are 29 40MHz channels available.

 

In my opinion the easiest way would be as you'd suggested, I'd get a cheap LTE hotspot device or another phone (for example the TP-Link M7200, ~$35) - and setup a vpn connecting either end.

[MrHaydenJr]

the bandwidth for this setup would actually be very low as it just handles a tcp/udp connection, the goal would be to use an alternative from standard wifi just to eliminate signal interferences and possibly increase range.... 

[MrHaydenJr]

 since these are on a radio frequency, is their an alternative to WiFi that could be used to do something similar in a p2p configuration? the goal would be a small lan, no internet required... maybe 3 devices max

 

(the robot has to be setup via laptop, but can be controlled by a phone or tablet, and then of course the robot would be on the network... )

[coreygibson]

would 2 phones be able transmit to each other over that distance? I wonder if it would be possible to use hamm radio signals to do it, ive seen texting over hamm but this might be a bit much.

[Donut417]

On 5/24/2022 at 5:27 PM, MrHaydenJr said:

is their a way to use two cell phones to create a point-to-point LAN using the cell phone (LTE) signals as the transmission medium.

Not sure this would be legal. The bands used for LTE are OWNED by their respective cellular providers. Unauthorized use of such bands would result in government fines and possibly the cellular provider in question issuing a lawsuit.