systems are constrained in important ways, relative to static systems. These constraints are intrinsic to mobility, and are not just artifacts of current technology:
- Mobile elements are resource-poor relative to static elements. At any given cost and level of technology, considerations of weight, power, size and ergonomics will render mobile elements less computationally capable than their static counterparts. While mobile elements will undoubtedly improve in absolute ability, they will always be at a disadvantage relative to static elements.
- Mobile elements are more prone to loss, destruction, and subversion than static elements. A Wall Street stockbroker is more likely to be mugged on the streets of Manhattan and have his or her laptop stolen than to have the workstation in a locked office be physically subverted. Even if security isn’t a problem, portable computers are more vulnerable to loss or damage.
- Mobile elements must operate under a much broader range of networking conditions. A desktop workstation can typically rely on LAN or WAN connectivity. A laptop in a hotel room may only have modem or ISDN connectivity. Outdoors, a laptop with a cellular modem may find itself in intermittent contact with its nearest cell.