The Tenuous Link

I had been planning to amaze everyone in my phone book with amazingly-fast rapid-fire SMSing. But I was going to cheat, and send them from my PC. I signed up to the BT Text SMS service, and even chucked in some money up-front for a stack of prepaid texts each month.

I did find a few applications on the net for sending SMS, but hadn't actually tried them out. Most of them turned out to be for a mobile handset with Bluetooth or IR. The ones that work using a landline modem didn't (work).

The closest I could get to technical details that I could understand are here: www.tek-tips.com/viewthread.cfm?qid=561830. The full gory details are in a document from ETSI called ES 201 912.

In summary, for a modem to be able to send SMS to the BT Text SMS Centre:

1. The modem must give the CLI (Caller ID) for incoming calls: just like an SMS telephone, the computer needs to know when the SMS center is dialling in with a new message.
2. The modem must support v.23 connections.
3. The modem must support fast connect (aka fixed mode?).
4. The modem must work in half duplex mode (1200 baud while transmitting and recieving data).

I actually have the only modem in Hampshire that does support BT "standard" Caller ID, but it falls down on the last requirement, which seems to be unusual. Oh well. Back to twiddling my thumbs.

// posted by Steven @ 10:24 PM