GMRS texting

[SvenMarbles]

Has anyone tried the GMRS texting functionality? I believe the GMRS-Pro is the only model currently in production that supports it. But under Part 95, it is permitted to transmit from an HT your GPS location as well as a “brief text message” via a data mode. 
 

Typically narrow banded data can have a longer functional range than phone. If FT8 can be used to send short data messages narrow banded on low power across the world, I’m interested to know what 5 watts can do to send a data burst. Could be a really nice feature to use with family if the coverage area is decent. 
 

Anyone here played around with it yet?

[kidphc]

Kinda tough.

Data burst can't be longer then one second.

"3) Digital data transmissions must not exceed one second in duration."

Can't have more then one data transmission inside of 30 seconds.

"(4) Digital data transmissions must not be sent more frequently than one digital data transmission within a thirty-second period,"

Data transmissions have to be manually activated. The devices can not store and forward packet modes for data.

Sounds like they don't want you to. Realistically, speaking even an aprs packet is 2.5 seconds long. Ft's' being streams and automated (well kinda), looks like verbiage was put in to stop exactly that kinda of thought.

Sent from my SM-S901U using Tapatalk

[SvenMarbles]

10 minutes ago, kidphc said:

Kinda tough.

Data burst can't be longer then one second.

"3) Digital data transmissions must not exceed one second in duration."

Can't have more then one data transmission inside of 30 seconds.

"(4) Digital data transmissions must not be sent more frequently than one digital data transmission within a thirty-second period,"

Data transmissions have to be manually activated. The devices can not store and forward packet modes for data.

Sounds like they don't want you to. Realistically, speaking even an aprs packet is 2.5 seconds long. Ft's' being streams and automated (well kinda), looks like verbiage was put in to stop exactly that kinda of thought.

Sent from my SM-S901U using Tapatalk


 

I’d be interested to know what the character limit would be. Depending on the “data mode” it could be enough to send a reasonable message. 1 per 30 seconds isn’t a terrible limitation

[kidphc]

I’d be interested to know what the character limit would be. Depending on the “data mode” it could be enough to send a reasonable message. 1 per 30 seconds isn’t a terrible limitation

Don't know what it is. But a one second date burst is quite small.

Maybe 1/2 of a standard aprs beacon without additional text?

Sent from my SM-S901U using Tapatalk

[WRXB215]

I'm pretty sure distance would still be typical UHF distance.

[Lscott]

5 hours ago, kidphc said:

Don't know what it is. But a one second date burst is quite small.

Until you have a dozen or so stations doing it on your channel. Then even a short data burst at frequent intervals is going to be irritating.

[kidphc]

Until you have a dozen or so stations doing it on your channel. Then even a short data burst at frequent intervals is going to be irritating.

Oh.. yea I agree. Listen to aprs frequency in a dense area.

What I was referring to was the amount of data that can be sent. Especially, something like FT. Damn symbols rate caps, lol

Sent from my SM-S901U using Tapatalk

[SteveShannon]

16 hours ago, WSAK691 said:

Has anyone tried the GMRS texting functionality? I believe the GMRS-Pro is the only model currently in production that supports it. But under Part 95, it is permitted to transmit from an HT your GPS location as well as a “brief text message” via a data mode. 
 

Typically narrow banded data can have a longer functional range than phone. If FT8 can be used to send short data messages narrow banded on low power across the world, I’m interested to know what 5 watts can do to send a data burst. Could be a really nice feature to use with family if the coverage area is decent. 
 

Anyone here played around with it yet?

The Garmin Rhino series GMRS radios have had it for many years, as well as very well done mapping and location exchange. It works well.  I use that, but I’ve not used the GMRS pro.

[WRYZ926]

The problem is that there is no standard format for the exchange of GPS information between the different manufacturers. Wouxun has their own version in their KG-Q10G too. It's kind of like the digital modes for amateur radio. You have DMR, Fusion, and D-Star. None of them work with the others.

[WRXB215]

5 minutes ago, WRYZ926 said:

The problem is that there is no standard format for the exchange of GPS information between the different manufacturers. Wouxun has their own version in their KG-Q10G too. It's kind of like the digital modes for amateur radio. You have DMR, Fusion, and D-Star. None of them work with the others.

Yep, I understand innovation, invention, and generally trying new things but industry standards are also very important. It's unfortunate that there still is not an industry standard for digital radio and especially GPS.

[WRYC373]

There could be I know theres Rattlegram that @OffRoaderX showed off a few weeks ago for short texts.

I think we would need opensource community standards ala APRS for GMRS and then like with amateur radio get enough people to buy the feature to show there's a market to integrate it.

 

My idea to offload some of the data limit:

Callsign via CW

TEXT DATABURST (1 sec or less limited by char count)

30 sec

Callsign via CW

LOCATION DATABURST (1 sec or less)

 

This is my very poorly thought out idea on how it could work with the limits in place (which I fully support to avoid GMRS becoming nothing but fax noises).

The listening program would decode the CW to text and attach it to the decoded databurst coming in the issue is it would be very sensitive to interference from repeater Idents. I think offloading the Station ID should save a little for texts at least. But may not be worth the extra hassle.

Remember closed standards are often dropped for the opensource standard if it is easy to adopt and has customers willing to pay for its implementation. Especially when there is no competing dominate standard.

"GMAPRS" would be really cool if we could do it and as long as the 1 sec limit every 30 sec is followed.

APRS uses 1200 Baud on VHF and 9600 Baud on UHF

https://www.amsat.org/amsat/articles/g3ruh/109.html  I found this link that says 9600Baud fits in 20Khz just barely which is what I thought so it may be very possible to do at least text or location if not location and text together.

 

TLDR: APRS could be adapted to GMRS to create an open standard the work needed would be heavy but its actually very possible with modifications to the existing protocol.

[flashover52]

The texting via GMRS has been available for a long time. Garmin Rhino’s were first to the game in the early 2000’s. It was a novelty then. It’s okay if there is a need to not talk. Unfortunately, the format doesn’t seem to work across hardware devices.