The first SMS message was sent over the Vodafone GSM network in the United Kingdom on 3 December 1992. Since then it has covered a long way but one thing is still same-the 160 characters limitation. An SMS can contain maximum 160 characters but the question is why it is so.

SMS

Transmission of SMS is controlled by MAP(Mobile Application Part)of SS7 protocol of GSM. It is also responsible for call handling packet data services location management etc.

When it was designed SMS just have Digital Coding System Signaling protocol limited to 140 octets or 1120 bits. Now every character consumes 7 bits. So we get this magic number of 160.If non-Latin alphabets like Chinese or Arabic are used, the limit is 70 characters because along with the flash SMS they consumes 16 bits per character and your digital data like images consumes 8 bit per character.

So that’s the reason behind that magic number and if you want details on some key terms used in this post you can Google them or Wikipedia is always there to help you.

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