Currently, SMS messages sent through the "AWS SNS service provider" employ $SITE->shortname as the sender ID. It can be a good improvement to add the Senderid to the configuration, so the admin has the possibility to change it. 

This modification would involve updating the code in the file sms/gateway/aws/classes/local/service/aws_sns.php, particularly within the "aws_sns" method. 

$senderid = $SITE->shortname;

// Remove spaces and non-alphanumeric characters from ID.

$senderid = preg_replace("/[^A-Za-z0-9]/", '', trim($senderid));

// We have to truncate the senderID to 11 chars. 

$senderid = substr($senderid, 0, 11);