1. A computer-implemented method for encoding an alphanumeric message, comprising: determining whether a phrase comprising a string of one or more symbols in the alphanumeric message is a numeric phrase, and if so, encoding the phrase in a compressed form according to a predefined numeric model; when the phrase is not a numeric phrase, matching strings of at least one symbol in the alphanumeric message with corresponding entries in a predetermined phrase dictionary, wherein each dictionary entry corresponds to a phrase code and replacing matched strings in the alphanumeric message with corresponding phrase codes to result in creating a compressed encoding of the phrase; and encoding at least a portion of the remaining symbols in the alphanumeric message using a statistical model based coding method.
10. The method of claim 1, wherein a phrase code corresponding to a dictionary entry represents a single word or an integer string of the type used to represent a telephone number, wherein the integer string may include a hyphen.