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PUBLIC TERRESTRIAL PACKET SWITCHED NETWORKS MESSAGING/DISPATCH ORIENTATION Amateur packet radio has been active in the 2- and 20-meter bands since the early 1980s. But recognizable pay-for-service packet switched offerings began in Chicago in 1986 with Motorola s DRN. With coverage in only three cities and weak marketing, DRN struggled for three years. In 1990 it was folded into a joint venture that also embraced IBM s .ield Service System. The result was ARDIS, a truly nationwide public packet data network. The formation of ARDIS was quickly followed by an alternative carrier: RAM Mobile Data. With extremely limited geographic coverage, RAM s early struggles were. | The Wireless Data Haadbaak Fourth Edition. James F. DeRose Copyright 1999 John Wiley Sons Inc. ISBNs 0-471-31651-2 Hardback 0-471-22458-8 Electronic 4 PUBLIC TERRESTRIAL PACKET SWITCHED NETWORKS 4.1 MESSAGING DISPATCH ORIENTATION Amateur packet radio has been active in the 2- and 20-meter bands since the early 1980s. But recognizable pay-for-service packet switched offerings began in Chicago in 1986 with Motorola s DRN. With coverage in only three cities and weak marketing DRN struggled for three years. In 1990 it was folded into a joint venture that also embraced IBM s Field Service System. The result was ARDIS a truly nationwide public packet data network. The formation of ARDIS was quickly followed by an alternative carrier RAM Mobile Data. With extremely limited geographic coverage RAM s early struggles were every bit as severe as that of Motorola s DRN. It was saved by a partnership with BellSouth Mobility which in 1998 became the sole owner. RAM was subsequently renamed BellSouth Wireless Data. BSWD has continued to expand its infrastructure and create supporting network alternatives in order to obtain nationwide coverage. In April 1993 a consortium of wireless carriers announced a series of regional systems called CDPD. Differing in only a few technical respects from ARDIS and RAM and very late to market CDPD s combined blood loss easily surpassed that of the earlier pioneers. CDPD s subscriber growth has been exceedingly slow. There have been vertical application successes initially in street-level public safety but the marketing emphasis is clearly shifting to horizontal applications. Since CDPD s announcement in 1993 many new packet data alternatives mostly regional or metropolitan have been placed in production or are being aggressively tested. Several services have already failed. 25 26 PUBLIC TERRESTRIAL PACKET SWITCHED NETWORKS 4.2 ALPHANUMERIC PAGING ORIENTATION In 1983 during the first unsuccessful IBM Motorola attempt to create a data radio joint .