Handheld and Ubiquitous Computing

Abstract

1 Personal mobile computingIn recent years, technology drivers changed significantly. High-end systems used to direct the evolution of computer architectures and systems. Now low-end systems drive technology, due to their large volume and attainable profits. Advances in technology enable portable computers to be equipped with wireless interfaces, allowing networked communication even while on the move. Whereas today's notebook computers and personal digital assistants (PDAs) are self contained, tomorrow's networked mobile computers are part of a greater computing infrastructure.Two trends -multimedia applications and mobile computing -will lead to a new application domain and market in the near future. Personal mobile computing (often also referred to as ubiquitous computing [17]) will play a significant role in driving technology in the next decade. In this paradigm, the basic personal computing and communication device will be an integrated, battery-operated device, small enough to carry along all the time. This device will be used as a replacement of many items the modern human-being carries around. It will incorporate various functions like a pager, cellular phone, laptop computer, diary, digital camera, video game, calculator and remote control. An important issue will be the user interface: the interaction with its owner. The device will support multimedia tasks like speech recognition, video and audio.Wireless networking greatly enhances the usability of a personal computing device. It provides mobile users with versatile communication, and permits continuous access to services and resources of the landbased network. A wireless infrastructure capable of supporting packet data and multimedia services in addition to voice will bootstrap on the success of the Internet, and in turn drive novel networked applications and services.However, the technological challenges to establishing this paradigm of personal mobile computing are non-trivial. In particular, these devices have limited battery resources, will handle diverse data types, and will operate in environments that are insecure, unplanned, and show different characteristics in time.Five years ago, in 1995, we started the MOBY DICK project, whose main focus was on the design of such a novel and versatile machine [12]. The MOBY DICK project started as a joint European project (Esprit Long Term Research 20422) to develop and define the architecture of a new generation of mobile handheld computers. The design challenges have been primarily in the creation of a single architecture that allows the integration of security functions (e.g. payment), externally offered services (e.g. airline ticket reservation), personality (i.e. these devices know what their owners want), and communication (mobile internet terminal). After one year, the research themes focussed on: systems architecture of