A:
Visit http://sms.vianett.com: Administration > Mobile Services > Subscription Groups > Group alerts

In order to configure this service, first a new campaign has to be created. Then a new or existing prefix has to be configured with the new campaign specified and with the type "SG Alert" selected. Assuming the subscription group has been created, this group can then be assigned to the campaign by using this page.

When the alert service has been set up, a message can be sent to all members of the subscription group by sending a message with the prefix assigned to the campaign, followed by the message the members should  receive.