While computing power may double every 18 months, battery life only doubles every five to 10 years. Since many of the new, invisible computing devices will be mobile, ensuring that they have a satisfactory power supply will be a major challenge. Much of the solution will come from innovations in power conservation, says Borriello. Invisible devices will save power by handling just a few functions or applications themselves, off-loading most others to computers that are connected to a continuous power supply, such as a desktop computer connected to a wall outlet. How computing functions and power requirements get partitioned between mobile and fixed computers is a key question for Institute participants.
Heat dissipation is another power-related constraint on mobile, invisible computers, adds Whitted.
While most power for mobile, invisible computing devices likely will remain chemical-based, we need to explore alternatives. We have to be creative about the possibilities. The interplay of bandwidth, power, and mobility presents us with challenges that don't arise in fixed computing. The problem is that bandwidth isn't free. So getting the most out of available bandwidth is important.