Every digital, and even some analog, mobile phone systems already incorporate some form of messaging. This allows subscribers to receive and sometimes send short text messages—essentially the same as paging, but with the data appearing on a mobile phone instead of a separate pager.

In theory, messaging services should allow people to receive email through their mobile phones and to dispense with pagers altogether. But in practice, neither of these objectives has been achieved, even in markets such as Europe, where every phone can receive messages and more than 90 percent can send them. The reasons are partly technical, thanks to length limits imposed by the very low data capacity, but mostly commercial.

Most operators charge for SMS ...

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