1. CUBE vs WECA Michael Dydyk
March 2000
IEEE P Working Group for Wireless Personal Area Networks
CUBE vs WECA Michael Dydyk
Michael Dydyk, Motorola

2. Agenda Define CUBE and WECA
March 2000
Agenda
Define CUBE and WECA
Objective of the Notice of Proposed Rule Making (NPRM)
Background
Home RF Working Group Request
Technical Claims of the Proposal
Issues Against the Proposal
Current Status of the NPRM
Michael Dydyk, Motorola

3. CUBE Committee for Unlicensed Broadband Enablement Intel Microlor
March 2000
CUBE
Committee for Unlicensed Broadband Enablement
Intel
Microlor
Motorola
Proxim
Siements
Michael Dydyk, Motorola

4. WECA Wireless Ethernet Compatibility Alliance 3Com Corporation
March 2000
WECA
Wireless Ethernet Compatibility Alliance
3Com Corporation
Aironet Wireless Communications, Inc.
Alantro Communications, Inc.
Apple Computer Inc.
Cisco Systems, Inc.
Dell Computer Corporation
Michael Dydyk, Motorola

5. WECA (Cont.) Intermec Technologies Intersil Corporation
March 2000
WECA (Cont.)
Intermec Technologies
Intersil Corporation
Lucent Technologies, Inc.
No Wires Needed, Inc.
Nokia, Inc.
Samsung Electro-Mechanics Co. LTD
ShareWave, Inc.
Symbol Technologies, Inc.
Michael Dydyk, Motorola

6. WECA (Cont.) Wayport, Inc. Zoom Telephonics, Inc. March 2000
Michael Dydyk, Motorola

7. March 2000
Objectives of NPRM
Amend the Part 15 rules regarding the operation of non-licensed spread spectrum systems.
Specifically, this Notice proposes to revise the rules for frequency hopping systems to allow for wider operational bandwidths.
Michael Dydyk, Motorola

8. March 2000
Background
FCC permits operation of non-licensed radio frequency (RF) devices on a non-interference basis.
Such devices must not cause interference to authorized services and they must accept any interference received from such services.
Michael Dydyk, Motorola

9. March 2000
Background (Cont.)
FCC permits operation of frequency hopping and direct sequence spread spectrum systems.
Spread Spectrum systems reduce the probability of causing interference to other signals occupying same spectrum
Michael Dydyk, Motorola

10. Frequency Hopping Spread Spectrum Systems
March 2000
Frequency Hopping Spread Spectrum Systems
Output power 30 dBm (1.0 watt)
Hopping channels 75
20 dB channel bandwidth 1 MHz
Time of occupancy <.4 sec within a second period
Michael Dydyk, Motorola

11. HomeRF Working Group Request-01
March 2000
HomeRF Working Group Request-01
Power output 25 dBm
Hopping channels 75
20 dB channel bandwidth 3 MHz
Time of occupancy .05 sec/hop within a 30 sec period
Michael Dydyk, Motorola

12. HomeRF Working Group Request-02
March 2000
HomeRF Working Group Request-02
Power output 23 dBm
Hopping channels 75
20 dB channel bandwidth 5 MHz
Time of occupancy .02 sec/hop within a 30 sec period
Michael Dydyk, Motorola

13. Technical Claims of the Proposal
March 2000
Technical Claims of the Proposal
Home RF Working Group (HRFWG) and now CUBE, claim that the proposal will not cause additional interference.
Overlapping channels will be needed to accommodate 75 hops.
Michael Dydyk, Motorola

14. Technical Claims of the Proposal (Cont.)
March 2000
Technical Claims of the Proposal (Cont.)
The average time of occupancy on any one frequency will increase.
The proposed reduction in output power and time of occupancy would offset any potential increase in interference.
Michael Dydyk, Motorola

15. Issues Against the Proposal
March 2000
Issues Against the Proposal
WECA argues that the changes will cause increased interference to Part 15 direct sequence spread spectrum systems.
WECA argues that the proposed systems will not be able to achieve substantially higher data rates that current 1 MHz systems because of the affects of in-building multipath interference.
Michael Dydyk, Motorola

16. Issues Against the Proposal (Cont.)
March 2000
Issues Against the Proposal (Cont.)
The power reductions proposed by HomeRF are inadequate to ensure that other users of the band will not encounter increased levels of interference.
Increasing hop rate does not reduce interference to other Part 15 users.
Increasing hop rate reduces throughput for FHSS systems.
Michael Dydyk, Motorola

17. Issues Against the Proposal (Cont.)
March 2000
Issues Against the Proposal (Cont.)
The preservation of at least 75 channels will result in a high degree of overlap for both the 3 and 5 MHz channels. The use of overlapping channels results in a level of interference which is even higher than co-channel interference.
Michael Dydyk, Motorola

18. Current Status of the NPRM
March 2000
Current Status of the NPRM
WECA and CUBE have submitted rebuttals (2 for WECA and 1 for CUBE) each claiming the other is wrong.
Silicon Wave (member of the Bluetooth SIG and HomeRF Working Group) has conducted an independent simulation and measurements on the issues and their results confirm the WECA position.
Michael Dydyk, Motorola