A sender can create and send a message that can be delivered to recipients with
SMS-enabled wireless stations regardless of the other communication capabilities
of the wireless stations and the network or network service providers of the recipients.
The sender creates a voice message and sends the message to a message server, which
stores the message in an interactive voice response (IVR) system. An SMS notification
is sent to the recipient and includes instructions for accessing the voice message
from the IVR system. The recipient views the SMS notification and accesses the
IVR system. After entering a password or otherwise authenticating the recipient
or the recipient wireless station, the recipient retrieves the message from the
IVR system. If it is not known whether the recipient has an SMS-enabled wireless
station, the message server initiates attempts to send SMS notifications using
multiple SMS message generation mechanisms.