Within hours of each other, Verizon Wireless, AT&T Mobility and T-Mobile USA introduced unlimited, flat-rate calling plans that, according to analysts, illustrate the extent to which mobile phone services are replacing fixed line telephony as a telecom staple. Targeted to high-end, high-volume customers, both plans are said to be the first of their kind to be rolled out by major, nationwide wireless carriers and are also predicted to set off a wave of unlimited wireless call plans that resemble those introduced by the long distance industry a decade ago. On Tuesday, Verizon was the first to announce its plan, priced at $99 per month, that provides unlimited nationwide voice minutes without domestic roaming fees. Later in the day, AT&T responded with its own unlimited calling plan, priced at $99.99 monthly, that is available for all wireless devices. T-Mobile also followed quickly with a similar plan, which also includes unlimited messaging. Last May, Sprint Nextel introduced an unlimited calling plan for residents of Philadelphia, Minneapolis, Tampa, western Nevada and portions of northern California that also covers e-mail, instant messaging, and Internet access for $119.99 monthly. The announcements by Verizon, AT&T and T-Mobile come amid predictions that Sprint will soon follow suit with its own unlimited nationwide plan. As Verizon Wireless chief marketing officer Mike Lanman observed that “the market [for high-end users] is getting bigger as people rely more and more on wireless,” AT&T Mobility CEO Ralph de la Vega said, “this is a highly competitive market and we’re committed to moving fast to meet our customer needs.”