Where does a ROKU tv get its signal from?

[brassplyer]

I have a ROKU tv and just discovered there are seemingly endless free channels, movies, tv shows through the ROKU TV option, so far the signal is rock solid. I have it in the garage for when I'm doing things there. What's attached to it are an LG Blu-Ray player, a Chromecast device to play content of one TV to another or from an Android phone and a coax cable for OTA TV. No cable, no satellite. The OTA signal here is very hit and miss even with an antenna mounted high in the attic crawlspace. I've never paid for any subscription, the options apparently are just included with the TV.

What's not clear to me is how it's receiving such a solid signal when the OTA digital signal around here is weak - I have a WIFI modem for internet through my phone company but I'm not aware of any signal coming out of it for any other provider.

Any insights as to how this TV is receiving the signal for the ROKU channels?

Thanks!

[Subtitles]

I have a ROKU tv and just discovered there are seemingly endless free channels, movies, tv shows through the ROKU TV option, so far the signal looks rock solid. What's attached to it are an LG Blu-Ray player, a Chromecast device to play content of one TV to another or from an Android phone and a coax cable for OTA TV. The OTA signal here is very hit and miss even with an antenna mounted high in the attic crawlspace. I've never paid for any subscription, the options apparently are just included with the TV.

What's not clear to me is where this signal is coming from - I have a WIFI modem for internet through my phone company but I'm not aware of any additional signal it provides for any other provider.

Any insights as to how the TV is receiving this ROKU signal?

Thanks!

I can only guess it is using the internet from your modem. Do a simple test and power off the wifi modem for a short time. If you still get the TV channels then it could be from the air with an inside antenna that picks up a lot of free TV channels.
There are flat antennas that you can stick on a window and it will pick up a lot of channels. I have a friend who does that and is quite happy with what she gets for free.
Can you check the Network setting in the menus? It will tell the internet source.
Also the Chromecast can pick up wifi from your modem. Try disconnecting it for a short while.