3. Technical issues
There are three technical issues specified by Mark Weiser.9 They are location, scale, and networking. Location is letting the computational device know where it is. This information then substitutes for native intelligence and is very good as simulating intelligence. There are two types of Location: Outdoor- examples are global positioning satellite (GPS), GPS receivers, digital wireless networks that come programmed with positioning information already, and radio (RF) signals to triangulate position (like GPS). Indoor- examples are active badges10, computational vision (wearing a beacon that can be tracked, color subtraction), and motion devices (detected presence of movement, unix logins, and home security)
Further segmenting the issue of Location, Philip Gray, in a paper entitled "Modelling Space for Location", discusses Location and Space with regard to Task Performance. These can be divided into three basic categories: 11 They are viability, method, and consequential subtasks (see Appendix).
The technical issue of Scale is considering the computer out it the environment. Different sizes of devices and each have their own purpose, dictating how many of these you can carry around. Xerox PARC is focusing on developing three different sizes: inch- "pads" (original Xerox PARC research- See Appendix), car keys, PDA, smartphones, voice recorders foot- "pads" (original Xerox PARC research- See Appendix) notebooks, tablets, digital paper (this is not a personal device, but rather as things in the environment that can rapidly customize to you) yard- electronic whiteboards, plasma displays (HDTV)
Networking is perhaps the most challenging because none of these ubicomp ideas will work unless the networking issues are technically advanced enough. Mark Weiser discusses these in his article "Computer Science Issues..."