Gary, all things are feasible
The are currently 3 front ends that provide somewhere for you to send your SMS. These front end systems talk to a pair of back end systems that process the data and place the spots. The separation of message receiver and message processor adds flexibility.
There’s a UK mobile number that accepts SMS input. It’s completely virtual, there isn’t a phone/modem listening to RF. Suffice to say when someone sends an SMS to it, their mobile service provider knows what to do to get the message to this number. When a message is received it is sent to one of the back-end processors via a web request.
There’s a US number that accepts SMS input that is provided by GoogleVoice, again a virtual number. When it receives an SMS it sends the content via email to the other back end processor.
Finally there is a VK number that is a real phone. It’s an Android phone running some software written by Allen VK3HRA that forwards the SMS content via a web page access to the first back end processor.
The two back end processors are almost identical, one receives spots via email, one receives spots via a web page. The rest of the systems is identical. The could be expanded to both offer email/web input and do all sorts of fall over redundancy and other really hoopy things given enough time.
The above describes how normal SMS get processed, The first addition was my personal Iridium system. This uses an off the shelf Iridium modem. The Earth bound side uses email to communicate with the mobile unit. i.e. the mobile talks via Iridium and the fixed sends sends and receives emails. The mobile unit has a fixed ID number that looks like a 14digit phone number and that is used to identify the sender. The email back end provider is used to process this.
The DeLorme InReach uses SMS for the Earth bound side. i.e. the mobile uses Iridium but the messages are sent/received via SMS to fixed users. This means the InReach user only has to send a spot to the UK SMS server and everything else is just dandy. The problem is the SMS number that appears in the InReach messages is not fixed. You get a different number everytime you use it. DeLorme’s severs are smart enough to match which InReach unit used which SMS number. So 2 way comms is effective. If the SMS number was fixed then I would not have needed to change my software. The change was to make the system spot the message was not really from a phone but a InReach unit and to locate a unique identifier in the message.
To handle SPOT messages a few things are needed. You need to be able to embed some unique identifier in your messages so that the system knows the message is real and not spam of some kind. I need to add a SPOT message parser to the code.
So if want to send me an email via your SPOT unit to mm0fmf_sota AT intermoose.com I can have a look at what is sent. Make it look like the current SMS format so I can inject it straight into the existing code.
i.e. “! W6 ??? 14.430 SSB ±5kHz”
I always like to acknowledge that this spotting system is made possible by the generous donation of resources by several people in addition to myself. The US number is provided by Andrew K1YMI, the US based back-end processor runs on a server provided by Jeremy NH6Z. The VK number and handler is provided by Allen VK3HRA.