iOS 18, Inreach killer?

Andrew Ricewrote:

So, just to clarify, it still didn't work when you turned off cellular data? Or it did? 

For me, yes. Again 14 model

Andrew Ricewrote:

So, just to clarify, it still didn't work when you turned off cellular data? Or it did? 

it did not.  15 pro running iOS 18.1.  cell data off, wifi off, also turned primary SIM off.  was in SOS mode but sat messaging function did not come up. 

The couple times I've used sat messaging I've not had to disable anything as I was in a cell dead zone

My iPhone 14 Pro prompted me to send a message via satellite in a dead zone at Mt. Rainier 3 days ago. I had recently upgraded to IOS 18. It was a bit clunky having to point at the quickly moving satellite. But it worked fine. I've loved how my inReach can be left un-attended as it finds and communicates with satellites. Is it that inReach uses better satellites, has more watts, or just a better antenna? 

inReach has a clear antenna bump. I predict this will take off and new iPhones will be coming with bump on the top. 

https://engineering.mit.edu/engage/ask-an-engineer/why-dont-cell-phones-have-retractable-antennas-anymore/ 

Antenna design is maybe the most important part of radio frequency communication. The physical characteristics need to be tightly matched to the frequencies used in order to maximize the energy that the antenna is able to gather or send. The cell bands in the USA are currently in 1700MHz-2100MHz. GPS is 1176.45MHz, 1227.60MHz, 1381.05MHz, and 1575.42MHz. Globalstar is 1617-1618MHz. Ideally you want the length of the antenna to be 1/2 or 1/4 of the wavelength of the frequency you're Tx/Rx on. 

What I can't find is how many dedicated antennas are put into the new phones. But I would be somewhat surprised if they aren't using the 1700MHz antenna and just dealing with some losses. Which means that a dedicated device with the right antenna for the frequency will always yield better performance, especially when sending (since the phone is only outputting less than 1W).

It's also worth mentioning that the folded "ducky" on the inreach is already a compromise. Folks working satellites in ham bands (analog) will use all kinds of crazy external arrays to make it happen on low power. But that's part of the fun, if you're into that kind of thing. Edit: I should also acknowledge that there are some nifty tricks you can do in software with digital signals, but RF is RF and better antenna matching will always beat software tuning.

Spopepro O.wrote:

Antenna design is maybe the most important part of radio frequency communication. The physical characteristics need to be tightly matched to the frequencies used in order to maximize the energy that the antenna is able to gather or send... a dedicated device with the right antenna for the frequency will always yield better performance, especially when sending

Thanks for the explanation. One of the main uses for my InReach is to send a trackpoint every hour. That way SAR will have an easier time finding me (or my sorry remains) even if I'm unconscious and unable to press the SoS button. I think you're saying that we can't expect mobile phones to have a similar feature, unless consumers are willing to accept a case design that accommodates a bigger antenna.

I have a new iPhone and an InReach. It is not often that I bring the InReach, I bring it when ice climbing in the polar circle, on big mountains and such things. It however does a lot of things that my iPhone does not do. Like has an acceptable battery life and does not die in cold weather...

Martin le Rouxwrote:

Thanks for the explanation. One of the main uses for my InReach is to send a trackpoint every hour. That way SAR will have an easier time finding me (or my sorry remains) even if I'm unconscious and unable to press the SoS button. I think you're saying that we can't expect mobile phones to have a similar feature, unless consumers are willing to accept a case design that accommodates a bigger antenna.

Probably for the foreseeable future. They could wrap a dedicated antenna inside that would work but packaging is already a huge issue with phones. There might be some super special software defined stuff that changes things, but I don't see it happening soon because at this level digital signal processing is *hard*. Hell, for all Apple's money and might they are *still* having to buy their radios from Qualcomm having nothing to show for 6 years of efforts to develop one in house. Another thing that could change is using something outside of the L-Band (like Ka, or E, both of which Starlink works on) which might prove easier to work with, or might supersede terrestrial cellular for everything at some point. It's hard to tell the future here and I'm only a lowly ham working analog (and sometimes APRS I guess...).

Spopepro O.wrote:

Probably for the foreseeable future. They could wrap a dedicated antenna inside that would work but packaging is already a huge issue with phones. There might be some super special software defined stuff that changes things, but I don't see it happening soon because at this level digital signal processing is *hard*. Hell, for all Apple's money and might they are *still* having to buy their radios from Qualcomm having nothing to show for 6 years of efforts to develop one in house. Another thing that could change is using something outside of the L-Band (like Ka, or E, both of which Starlink works on) which might prove easier to work with, or might supersede terrestrial cellular for everything at some point. It's hard to tell the future here and I'm only a lowly ham working analog (and sometimes APRS I guess...).

Starlink is a lot different than globalstar.  T-Mobile should have general texting and perhaps voice and data via starlink using unmodified cell phones sometime around the beginning of the year.   It was supposed to be this quarter but has been delayed a little.  T-Mobile has demoed text, voice and data to the cell phone.  The biggest hurdle right now is getting FCC approval for increased out of band transmission (interference) and getting a critical number of the new satellites in orbit (300 I think).  Starlink's service is exclusive to T-Mobile for 1 year then Starlink can sell the service to other cell phone providers.  T-Mobile will not require pointing of an antenna towards a satellite.  Video call demo

 ATT and Version are also working toward texting/voice/data using AST spacemobile satellites but it is probably a couple of years off.   I don't think either Version or ATT solutions will require pointing towards a satellite either.  

They days of inreach, spot and the like are numbered.  For T-Mobile subscribers that number could be quite small.

Spopepro O.wrote:

 Ideally you want the length of the antenna to be 1/2 or 1/4 of the wavelength of the frequency you're Tx/Rx on. 

It's a bit of a ham rabbit hole, but I was always amazed at how precisely I had to adjust the length of my vertical antenna. I would be talking to people as far away as Russia on the twenty meter wavelength (14.229 MHz). I did it at Smith Rocks, standing by my truck with 12 volts. I'd have to set my antenna to exactly one quarter of 20 meters: 16 feet, 5.3 inches before it could transmit. But it was as clear as a cell phone. And people were doing that back in 1920. Ultimately I got bored with ham, but still have all the gear, it's cool stuff. The tech they pack into cell phones is beyond amazing.