The future of GPRS and Industrial Automation?

I have been working more on local RF mesh than cellular, so my blog has been quiet.

However, users should be aware that GPRS in on the way out.  AT&T (and others) will swear up and down that they still fully support it, however we have customers reporting that their mobile (truck) based systems using GPRS are finding more and more dead-spots.

I agree that GPRS is not dead.  However, before investing in a GPRS-only cellular devices, consider the facts and your needs:

1. AT&T stopped certifying new non-3G devices years ago.
2. AT&T has been rumored to be reallocating air/RF-space away from GPRS to 3G technologies because the 3G makes much better use of this scarce resource - so more happy customers with 3G than GPRS. 
3. AT&T claims to have fully adjusted their pricing so that 3G is comparable to GPRS - they were forced to do this because A) they don't want more/new GPRS users, but B) huge customers were still going GPRS because it was cheaper.  So I have been told this is less true now.
4. AT&T claims to not be killing GPRS ... yet.

So if you roll the above facts together, I speculate that what is happening is that more GPRS devices are being squeezed into sharing less bandwidth, so whereas before a dozen GPRS devices might share 5 or 6 units of 'resource', now they might need to share 1.

If true, this means that the devices have lost bandwidth in recent years, so are now running on a fraction of what they had a few years ago.  The net result is that devices which upload say 200 bytes a day likely won't notice a difference, however anyone trying to open a fancy web page might discover the task nearly impossible.

GPRS runs at from 9600 to 80kbaud, but devices are allotted 'slots', so think time-division-multiplexing & other forms of fair sharing.  So if a tower offers 28.8kbps service to one GPRS device, and 3 more GPRS devices come online, then in theory they all may see closer to 7kbps throughput.  So the device sending a single small UDP or SMS packet won't notice, while the device which requires successfully sending 350 large packets end-to-end will notice a huge drop in performance, and if the client/server have 'task timers', they may discover that they can no longer complete the task before the connect drops or task-timers expire.

So bottom line - AT&T has not yet killed GPRS, but they clearly have it lined up against the firing-wall!  People who have tiny data needs can still safely use GPRS if their ROI window is fairly short-term (a few years).  However, people wishing to EVEN OCCASIONALLY move a 1/2 Meg file for firmware update or diagnostics may find GPRS less and less usable.  Those who plan to routinely move even dozens of K-bytes of data might begin to see reliability problems, so should move to 3G devices.