Today I got a unhappy customer who has a EFTPOS machine(from Payment Express, they supply wireless EFTPOS machine with Spark SIM) that can not take any payment, and they are not able to reach me since my mobile number goes to voice mail(which I didn't receive texts regarding the new voice mail)... Unlucky that their shop is not too far away from my place so they got me at last :-( That's when I found that my mobile shows a good signal but can not dial or receive any phone calls,  just like what happened last year(https://www.geekzone.co.nz/forums.asp?forumid=39&topicid=243173).

So I checked Spark website, this time the website does mention a maintenance in my area which says "Halfway Bush (between 20th November 2019 at 09:00 and 21st November 2019 at 18:00, up to 3 hours)". I am wondering for such maintenance affecting large(well, Dunedin is small compare to Auckland) area, is it possible that Spark can broadcast a SMS before the maintenance starts and another one when it finishes, so people that do have business rely on mobile network can prepared for this outage? It will be even better to have a better timeframe when it happens/ends, since from what I read from the sentence, it could happen anytime in a 2 days frame, which should only take no more than 3 hours but now it is more than 5 hours and my mobile still can't make any phone calls, and I guess the shop owner who has to shuts the door is more frustrate than me.

BTW, the SMS broadcast to mobile devices connected to a certain cell tower is possible right?