Linked Home Repeater / Car Hotspot

[sjmahler]

I am in the process of putting up a home repeater and have a PI ready to add linking.  I was thinking that a GMRS HotSpot in my car would be nice (there are no repeaters in the "county").  I have noticed some articles talking about no hotspots. I have noted a few reasons, but I can't be sure that I have seen all discussion or the newest discussion.

My concept is a part 95 E radio, a radio interface and a little PI with WIFI.  PI goes to the car WIFI, poof you have a link to the HOME Repeater. (It works, I do this with an OpenSpot.)

One post talked about a problem with FRS radios. To mitigate this problem I would program the hotspot radio just like a repeater with the pair upside down. The HT in the car set to one of the normal repeater channels. Add an out of the way DCS tone to the system.

Another post talked about level setting.  I see this as a universal issue with FM repeaters from any radio service being linked. If the hotspot can be calibrated to meet deviation / level standards I don't see it as an issue.  GMRS is certainly more appliance than ham radio. But, some do have the skills and equipment.

So what's the word fellas, are we OK with carefully designed hotspots (or maybe better named a "half duplex node").

[gortex2]

So you want to change GMRS to ham radio ? 

I don t know of a part 95 certified hotspot. I also don't get the concept. If you cant talk to the repeater dial your cell phone ? 

 

[Sshannon]

11 hours ago, sjmahler said:

I am in the process of putting up a home repeater and have a PI ready to add linking.  I was thinking that a GMRS HotSpot in my car would be nice (there are no repeaters in the "county").  I have noticed some articles talking about no hotspots. I have noted a few reasons, but I can't be sure that I have seen all discussion or the newest discussion.

My concept is a part 95 E radio, a radio interface and a little PI with WIFI.  PI goes to the car WIFI, poof you have a link to the HOME Repeater. (It works, I do this with an OpenSpot.)

One post talked about a problem with FRS radios. To mitigate this problem I would program the hotspot radio just like a repeater with the pair upside down. The HT in the car set to one of the normal repeater channels. Add an out of the way DCS tone to the system.

Another post talked about level setting.  I see this as a universal issue with FM repeaters from any radio service being linked. If the hotspot can be calibrated to meet deviation / level standards I don't see it as an issue.  GMRS is certainly more appliance than ham radio. But, some do have the skills and equipment.

So what's the word fellas, are we OK with carefully designed hotspots (or maybe better named a "half duplex node").

First, I don’t know, but here are the regulatory concerns I would have:

• This places GMRS communications onto the cellular data network. I suspect this is the item the FCC would be most concerned about, if they care at all.  If nobody complains then you can probably get away with it.  It’s entirely possible that some of the nodes on the MyGMRS network leverage a cellular data hotspot already.
• Hotspot radio (meaning the transceiver chip built into the hotspot) is not type certified.

But really, what’s the point?  If you have two people using gmrs radios to talk to cellular hotspots in order to talk to each other, why not just talk on the phone? Is the allure of talking on a handheld radio so great that you intentionally convert to half duplex and push to talk in a larger box?  I have a similar lack of understanding for people in the ham world who record QSOs between their handheld radios using hotspots on both ends.  Where’s the challenge?

[sjmahler]

I wasn't considering a commercial hotspot.  I was going to marry a type 95e radio to a raspberry pi, throw asterisk and allstar on it, and go from there.

[Sshannon]

Here’s what the fcc site says:

“You can expect a communications range of one to twenty-five miles depending on station class, terrain and repeater use.  You cannot directly interconnect a GMRS station with the telephone network or any other network for the purpose of carrying GMRS communications, but these networks can be used for remote control of repeater stations.”

https://www.fcc.gov/wireless/bureau-divisions/mobility-division/general-mobile-radio-service-gmrs

[sjmahler]

11 hours ago, Sshannon said:

First, I don’t know, but here are the regulatory concerns I would have:

• This places GMRS communications onto the cellular data network. I suspect this is the item the FCC would be most concerned about, if they care at all.  If nobody complains then you can probably get away with it.  It’s entirely possible that some of the nodes on the MyGMRS network leverage a cellular data hotspot already.
• Hotspot radio (meaning the transceiver chip built into the hotspot) is not type certified.

But really, what’s the point?  If you have two people using gmrs radios to talk to cellular hotspots in order to talk to each other, why not just talk on the phone? Is the allure of talking on a handheld radio so great that you intentionally convert to half duplex and push to talk in a larger box?  I have a similar lack of understanding for people in the ham world who record QSOs between their handheld radios using hotspots on both ends.  Where’s the challenge?

You have an interesting question about Cell Data being part of the PSTN.  I leapt to PSTN being limited to voice channels.  Early on the concept of the capacity needs for everyone having a modem connected, dial up style, was terrifying.  Modems killed the PSTN usage / all trunks busy calculations that had been used for years.

So the question is ... is cell data part of the PSTN.  It is not carried on a voice channel.  I believe cell data is on a totally isolated set of frequencies.  I guess some research is in order !! 

[Sshannon]

4 minutes ago, Sshannon said:

You cannot directly interconnect a GMRS station with the telephone network or any other network for the purpose of carrying GMRS communications,

 

1 minute ago, sjmahler said:

You have an interesting question about Cell Data being part of the PSTN.  I leapt to PSTN being limited to voice channels.  Early on the concept of the capacity needs for everyone having a modem connected, dial up style, was terrifying.  Modems killed the PSTN usage / all trunks busy calculations that had been used for years.

So the question is ... is cell data part of the PSTN.  It is not carried on a voice channel.  I believe cell data is on a totally isolated set of frequencies.  I guess some research is in order !! 

I’m not sure it matters. See the bold portion of the preceding quote. It says “or any other network…“

That seems pretty clear but I’d like to point out that the actual wording in the regulations are not phrased that way.

 

[gortex2]

I still dont get the concept. Pick up your cell.