Texting hits telly

Now you can send text messages by TV. The scheme is described in US application 2003/226143 by Comverse, a software house in Wakefield, Massachusetts. It exploits the fact that all digital pay-TV receivers have a unique ID number. To transmit a text message, the sender addresses it to the pay-TV company and adds a user ID that identifies the target receiver. Text messages are short enough to slot into spare capacity in the digital TV signal, and pop up as a password-protected prompt on the recipient’s screen.