Recent developments attest to wide interest in wireless asynchronous transfer mode (ATM). The Federal Communications Commission (FCC), for example, recently announced that it will open up 350 MHz of bandwidth in the 5-GHz band for inexpensive Internet access at schools and libraries. Moreover, in June 1996, the Wireless ATM Working Group was formed within the ATM Forum. Bell Labs has been working on a wireless ATM prototype in its Mobile information infrastructure (MII) project, which is partially funded by the National Institute of Standards and Technology of the U.S. Government. This paper describes the MII project, outlines several key technical issues and their proposed solutions, and discusses standardization and prototyping efforts. It also describes the system architecture; the protocol stack; the physical, multiaccess, and data link layers; connection control, location management, the handoff algorithm, and distributed address resolution; prototyping; standards; and a migration strategy from today's wireless local area network (LAN) to the future wireless ATM LAN.