SMS Facility

SMS stands for short message service. It’s a protocol that helps send short messages over wireless networks. Unlike many services in use today, such as MMS and other data-driven instant messaging services, SMS still works on the fundamental voice rather than the data part of the wireless network. It was initially built for GSM networks but continued to run on CDMA and HSPA in the 3G era, 4G LTE, and even modern 5G networks.

SMS allows for text messages of 160 characters (letters, numbers, and symbols) in length. For other languages with a wider range of characters, such as Chinese or Arabic, the maximum message size limit is just 70 characters. This is partly because SMS messaging was more of an afterthought, added to the spare bandwidth available on wireless voice networks. There was always a limit on how large these messages could be.