According to a report in the People's Daily newspaper, China has started work on a national public emergency warning to issue alerts within ten minutes ("China to build 10 min emergency warning system", Han Shasha, People's Daily Online,m 16:24, November 23, 2011). No technician details are provided, but it is likely that text messages via mobile phones will be used.
There have been problems experienced with prompt message delivery with the landine voice message part of the Australian Emergency Alert System. There have also been problems with formatting and addressing of the SMS based text messages. China should be able to learn from this experience.
One option might be to ring land-line phones with a distinctive cadence to alert citizens of an emergency. They could then turn on their TV, radio, or mobile phone for details. This would get around the problem of having to broadcast the voice message over the phone network, which is not set up for broadcast. This would also alert the citizens to an emergency situation, with them then in the frame of mind to receive the details.
Also use of cell broadcast for the delivery of text messages to mobile phones would be an option to consider. This gets around addressing and capacity problems, but still has some technical problems of its own.