Superman's communications needs have always been a problem - shouting "Help Superman" doesn't really cut it if you're 500 miles from Metropolis.
There are a few problems with an ordinary cell for Superman, of course; it's easy to trace their location, and there are problems if they're used at high altitudes - your call uses bandwidth on hundreds of cells instead of the four or five nearest a caller on the ground. Satellite might be a better answer, but they're conspicuous and traceable, unless you have some cooperation from the satellite service provider - note that Bruce Wayne owns various telecommunications companies.
What he needs really is an untraceable phone satellite phone disguised as an ordinary cell phone, with a different number for each class of caller, and a different ring tone that identifies which number has been used, plus something (preferably something ultrasonic nobody else can hear) to identify known callers e.g. a warning that Lois is calling him as Superman and he should respond in character even though it's her.
Fortunately the WayneTech of my Supergirl Returns universe can supply these at very reasonable rates, and I'm sure that H.G. Wells can help Clark get there to cut a deal...
