Possible that the devices you monitor do self checks like my home alarm
system. If at the time there is no service this could trigger an alarm
depending on how the system is setup.
As radio devices are subject to drop out I would either bypass the checking
of the GSM network or have some sort of time delay that would extend it to
1 or 2 minutes (even more depending on the system and its use).

There are a lot of reasons why you may not be able to get "connected" to
the GSM network, for example congestion which is probably more likely on
poor weather days due to people calling taxis and road side assistance. The
sun has storms that can mess with radio signals along with tin foil on the
head (joke).

Do you find most failures occur on a Friday night?
Maybe a simply solution could be to change networks and select one that
offers better coverage in the area that the systems are located.

This link may help as well http://techrepublic.com.com/5208-6230-0.html?
forumID=83&threadID=200396&messageID=2137356

:-P


--
Posted via a free Usenet account from http://www.teranews.com