Dewayne Hendricks

1
What Went Wrong with U-PCSor......

• Dewayne Hendricks
• Tetherless Access

2
No matter where you go, there you are.
Buckaroo Banzai
3
Everything that Im going to tell you is the
truth... Give or take a lie or two!
Wyatt Earp Sunset
4
Setting the Stage
5
Amateur Radio Service (ARS) as a Research Metaphor

• Been around for almost 100 years
• Spectrum allocations treated as commons
• Minimal power rule
• Self policing. Self certification of equipment
• None of the problems with experimental license
  (approval process)

6
ARS Spectrum Allocations

• 50-54 MHz
• 144-148 MHz
• 219-220 MHz
• 222-225 MHz
• 420-450 MHz
• 902-928 MHz
• 1240-1300 MHz
• 2390-2450 MHz
• 3.3-3.5 GHz
• 5.650-5.925 GHz

7
ARS Spread Spectrum RD

• Took place from 1992-1997
• Used Special Temporary Authorization (STA)
• Robert Buaas STA
• Tucson Amateur Packet Radio (TAPR) STA
• Results supported the use of spectrum overlay

8
TAPR Statement of Direction - 1996

• TAPR believes that the technical facts support
  our conviction that conventional and spread
  spectrum systems can coexist without detriment to
  conventional systems on all frequencies from MF
  to EHF. To this end, TAPR will begin to research
  spread spectrum systems that will develop
  technology for future deployment.

9
Amateur Radio Service Lessons Experiences

• Packet radio effort started around 1981
• Based on early ARPA/DARPA work
• Low cost interface device (TNC) - 300
• Dynamic routing
• 56 Kbps hardware by 1986

10
Amateur Radio Service Lessons Experiences

• Global packet radio networks in place by 1987
  using either AX.25 or TCP/IP protocols
• Bandwidth increased by using Part 15 H/W and
  homebrew
• Mesh networks in place by 1991 and MANs connected
  by wired Net by 1995 (ampr.org)

11
Amateur Radio Service Conclusions

• Wireless networks can be built in a cooperative
  manner where the whole is greater than the parts
• Using spectrum as a commons can work through use
  of simple rules
• Innovation occurs when driven by needs

12
ARS Source Material

• The ARRL Spread Spectrum Sourcebook - ARRL
  
• Spread Spectrum Update Tales from the Rebel
  Alliance - TAPR
• ARRL/TAPR Digital Communications Conference
  Proceedings -

13
Unlicensed Roadmap

• The road begins with SS NOI in 1981
• SS RO in 1985 starts the engines
• First equipment appears in 1988
• Other countries adopt unlicensed SS and it goes
  global
• IEEE 802.11 Committee forms

14
The Divergent Paths

• Make the best of what weve got..
• Life would be better in a new briar patch

15
Make the best....

• Metricom
• Tetherless Access Ltd. (TAL)

16
Ricochet (Metricom)
17
First TAL SS Mesh Router - 1995
18
New Briar Patch

• Data-PCS

19
Apple Newton - Ad hoc Wireless
20
Conflict of Styles
Rough consensus and running code vs March to
the sea on a wing and a prayer
IT Companies vs The Telcos
21
U-PCS

• 1910-1930 MHz Total
• 1910-1920 MHz Data
• 1920-1930 MHz Voice
• Asked for 40 MHz
• Later 2390-2400 MHz added
• Now 1920-1930 MHz (Big market success)

22
Cognitive Radio Example

• Cognitive Radio differs from a Smart Radio in
  that it operates non-deterministically (uses
  heuristics)
• Able to sense and adapt to its environment
• IEEE formed 802.22 to develop cognitive radio
  standards

23
False Scarcity

• Paper by Paul Baran in 1994. Available at
  
• Discussed use of spectrum as an open commons
• Defined a set of heuristic rules for smart
  radios

24
(No Transcript)
25
(No Transcript)
26
CR Rules of the Road (3)

• Rule 6. If you feel you absolutely must beat up
  somebody, be sure to pick someone smaller than
  yourself. (Now this is a less obvious one, as
  weak signals represent far away transmissions so
  your signals will likely be attenuated the same
  amount in the reverse direction and probably not
  cause significant interference.)

27
(No Transcript)
28
The Future?
29
No matter where you go, there you are.
Buckaroo Banzai