used or are without PCs will use the smaller, simpler
devices and avoid the PC’s complexity; and existing
PC users will adopt them for simplicity, mobility, and
functionality. We clearly see these small personal
devices with annual volumes of several hundred million units becoming the single universal device evolving from the phone, PDA, camera, personal
audio/video device, Web browser, GPS and map, wallet, personal identification, and surrogate memory.
With every TV becoming a computer display, a
coupled SFF becomes the personal computer for the
remaining applications requiring large screens. Cable
companies will also provide access via this channel as
TV is delivered digitally.
Ubiquitous Wireless: WiFi, Cellular Services, and
Wireless Sensor Nets. Unwiring the connection
around the computer and peripherals, televisions, and
other devices by high-speed radio links is useful but
the function is “unwiring,” and not platform creation.
Near-Field Communication (NFC) using RF or magnetic coupling offers a new interface that can be used
to communicate a person’s identity that could form a
new class for wallets and identity. However, most
likely the communication channel and biometric technology taken together just increase the functionality of
Wireless Sensor Nets: New Platform, Network,
and Applications. Combining the platform, wireless
network, and interface into one to integrate with
other systems by sensing and effecting is clearly a
new class that has been forming since 2002 with a
number of new companies that are offering
unwiring, and hence reduced cost for existing applications, such as process, building, home automation,
and control. Standards surrounding the 802.15.4
link that competes in the existing unlicensed RF
bands with 802.11xyz, Bluetooth, and phone transmission are being established.
New applications will be needed for wireless sensor
nets to become a true class versus just unwiring the
world. If, for example, these chips become part of
everything that needs to communicate in the whole IT
hierarchy, a class will be established. They carry out
three functions when part of a fixed environment or a
moving object: sense/effect; recording of the state of a
person or object (things such as scales, appliances,
switches, thermometers, and thermostats) including
its location and physical characteristics; and communication to the WiFi or other special infrastructure
network for reporting. RFID is part of this potentially
very large class of trillions. Just as billions of clients
needed millions of servers, a trillion dust-sized wireless
sensing devices will be coupled to a billion other
Bell’s Law explains the history of the computing
industry based on the properties of computer classes
and their determinants. This article has posited a
general theory for the creation, evolution, and death
of various priced-based computer classes that have
come about through circuit and semiconductor
technology evolution from 1951. The exponential
transistor density increases forecast by Moore’s Law
[ 6] being the principle basis for the rise, dominance,
and death of computer classes after the 1971 microprocessor introduction. Classes evolve along three
paths: constant price and increasing performance of
an established class; supercomputers—a race to
build the largest computer of the day; and novel,
lower-priced “minimal computers.” A class can be
subsumed by a more rapidly evolving, powerful, less-expensive class given an interface and functionality.
In 2010, the powerful microprocessor will be the
basis for nearly all classes from personal computers
and servers costing a few thousand dollars to scalable
servers costing a few hundred million dollars. Coming rapidly are billions of cell phones for personal
computing and the tens of billions of wireless sensor
networks to unwire and interconnect everything. As
I stated at the outset, in the 1950s a person could
walk inside a computer and by 2010 a computer
cluster with millions of processors will have
expanded to the size of a building. Perhaps more significantly, computers are beginning to “walk” inside
of us. c
1. Bell, C.G. The mini and micro industries. Computer 17, 10 (Oct. 1984),
2. Bell, C.G. Multis: A new class of multiprocessor computers. Science 228
(Apr. 26, 1985) 462–467.
3. Bell, G. and Strecker, W. Computer structures: What have we learned
from the PDP- 11. IEEE Computer Conference Proceedings (Florida, Nov.
4. Christensen, C.M. The Innovator’s Dilemma. Harvard Business School
5. Gray, J. and Shenoy, P. Rules of thumb in data engineering. In
Proceedings of ICDE200 (San Diego, Mar. 1– 4, 2000). IEEE press.
6. Moore, G.E. Cramming more components onto integrated circuits.
Electronics 8, 39 (Apr. 19, 1965); revised 1975.
7. Nelson, D.L. and Bell, C.G. The evolution of workstations. IEEE Circuits and Devices Magazine (July 1986), 12– 15.
GORDON BELL ( firstname.lastname@example.org) is a principal researcher in
Microsoft Research Silicon Valley, working in the San Francisco
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