Short Message Service (SMS) is the arrangement through which humans can forward abrupt argument letters amid corpuscle phones. In the English alphabet, these letters are bound to 160 characters each, including spaces. This limitation after-effects from the arrangement on which SMS operates. Instead of application the primary arrangement for blast communication, SMS uses a approach advised to forward baby packets of advice amid corpuscle phones and corpuscle towers. The 160-character SMS absolute is artlessly a aftereffect of the originally bashful use to which this approach was put. The approach was alleged as the base for SMS because the arrangement could be implemented easily, with basal charge for new infrastructure.

            Cell phones are accurate by a arrangement of building amenable for transmitting calls. These building consistently acquaint with the corpuscle phones they abutment application a abundance alleged the ascendancy channel. The ascendancy approach is acclimated to broadcast advice about the area of phones and towers; it is aswell acclimated to arrange calls. Unlike the calls themselves, these processes crave alone baby exchanges of information. When corpuscle buzz providers absitively to set up a arrangement for transmitting abbreviate messages, this approach was simple to use. All that was all-important was the accession of a Abbreviate Bulletin Account Center to accept letters and avenue them to adapted building at an appropriate time.

            The arrangement was advised by an alignment alleged the Global Arrangement for Mobile Communications (GSM), chaired by Friedhelm Hillebrand. GSM artlessly analyzed the types of letters that humans forward to anniversary added and assured that humans would acquisition a bulletin account advantageous even if it alone transmitted amid 100 and 200 characters. Restricted by the accouterments to a absolute of 140 bytes, or 1120 bits, they advised a arrangement that could encode a baby amount of characters with 7 $.25 each. This yielded a best manual admeasurement of 160 characters.

             Other factors can lower the limit. Users can forward best letters by concatenating a accumulation of SMS packets. However, the absolute on these alone packets is bargain to 153, back anniversary have to aswell accommodate metadata anecdotic its accord to the added apparatus of the beyond message. SMS users who ambition to acquaint with added alphabets aswell are bound to beneath characters. Chinese, Arabic, and Cyrillic SMS use UTF-16 encoding, which requires 16 $.25 per appearance and appropriately has an SMS absolute of 70 characters per message. Sending concatenated letters application UTF-16 encoding decreases this SMS absolute to 67 characters.

            The 160-character SMS absolute has become broadly known, and abounding altered organizations are designing means to acquaint aural this constraint. The accepted messaging account Twitter is set up to accommodate to this limit. Twitter allows users to column a best of 140 characters, with the actual amplitude taken up by user names. Abounding account outlets and politicians absolution abbreviate letters accessible to be transmitted through Twitter or beatific anon to subscribers' corpuscle phones. New casework accommodate altered means of sending added advice amid corpuscle phones, but the 160-character SMS absolute charcoal ubiquitous.