UNIX For Nomads: Making UNIX Support Mobile Computing

Traditionally, the Unix operating system has been associated with deskbound machines tethered to the wall by a power cord and an Ethernet cable. Making Unix support a more nomadic model of computing requires changes in the entire system, from the kernel level through the user command set of applications. In this paper, we present the results of an experimental prototype development effort targeted at supporting a nomadic computing model in Sun's Solaris 2 SVR4-based platform. The development involved enhancements in four primary areas: kernel changes to support power management and checkpointing of system state, drivers and other kernel support for the new PCMCIA bus standard, support for serial line networking, and a new electronic mail application designed specifically for accessing mail over slow serial connections. The paper discusses enhancements and modifications to the design of standard Solaris system components in each of these areas.