Ann: SAS Completes World First Phone Calls, Instant Messaging, page-249

And this is the reason why some people are still hesitant to jump in.
There are so many market streams available to SAS, but problems will be the spectrum they will operate in (spectrum licenses are traditionally very expensive) the bandwidth available, upload/download speed, QOS (quality of service) and then interconnectivity to the rest of the universe.
If they can meet or exceed the 3g/4g/5g traditional telco wireless speeds/quality and remain cost competitive, then they will certainly shake up the industry. If they are just going to operate and provide coverage/service where others aren't operating currently, then it'll be down to marketing what they can do and wait for market uptake. Not sure how they'll go in that instance particularly if they are providing service to poorly developed economic countries.