A cellular network facility that allows users to send and receive text messages of up to 160 alphanumeric characters on their handset.
Source(s):
NIST SP 800-101 Rev. 1
a mobile phone network facility that allows users to send and receive alphanumeric text messages of up to 160 characters on their cell phone or other handheld device
Source(s):
NISTIR 7250
under Short Message Service
NISTIR 7387
under Short Message Service