Got my Triband working today :-)) . Did a little googling for rebooting the modem.
From 1. http://en.wikipedia.org/wiki/Expect and 2. http://www.linuxforums.org/forum/linux-programming-scripting/63702-can-you-write-script-starts-telnet-then-input-commands-into-telnet.html
I think this little script for rebooting a GLB-502T can be scheduled with cron. Its bound to work for other modems too; with some modifications.
<script> #!/usr/bin/expect
spawn telnet 192.168.1.1
expect "BusyBox on localhost login: " send "root\r"
expect "Password: " send "password\r"
expect "# " send "reboot\r"
expect "%" send "exit\r"
expect eof </script>
Is surely better than timers and such. Regards.