1. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 1 Project: IEEE P802.15 Working Group for Wireless Personal Area Networks (WPANs) Submission Title: Qualitative Spectral Analysis of Common Household Light Sources Date Submitted: March 2009 Source: Rick Roberts, Intel Corporation Address: Intel Oregon Labs Voice: 503-712-5012, E-Mail: richard.d.roberts@intel.com Re: Abstract: Purpose: Notice:This document has been prepared to assist the IEEE P802.15. It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein. Release:The contributor acknowledges and accepts that this contribution becomes the property of IEEE and may be made publicly available by P802.15.

2. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 2 Qualitative analysis means that all amplitude levels are relative to the 120 Hz spectral line. Lab setup: representative light bulbs, light dimmer, light source and photodetector. During testing the detector was battery powered to eliminate 60 Hz.

3. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 3 Typical spectral output from the photodetector. This particular spectrum is from a halogen light bulb with the dimmer at 75% (100% is full brightness). Harmonic Envelope

4. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 4 The research was to characterize the harmonic spectral envelope for various readily available household lighting. All lights were operating on 60 Hz. Bulb AGE Halogen bulb, 150 watts Bulb BBright Effects, 60 Watt incandescent Bulb CGE Dimmable CFL, 15 watts Bulb DFEIT Electric, 15 watt Ecobulb CFL Bulb EBright Effects, 13 watt Soft White CFL Bulb FBright Effects, 11 watt Daylight CFL 24”24 inch fluorescent tube 48”48 inch fluorescent tube CFL: compact fluorescent lamp

5. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 5 150 Watt Halogen Bulb Spectrum is confined to approximately less than 2 KHz Dimmer Values: 1.0 … full ON 0.25 … dim

6. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 6 Dimmer Values: 1.0 … full ON 0.25 … dim 60 Watt Incandescent Bulb Spectrum is confined to approximately less than 2 KHz

7. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 7 Dimmer Values: 1.0 … full ON 0.25 … dim Dimmable 15 watt CFL Spectrum is confined to approximately less than 22 KHz

8. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 8 CFL Non-dimmable Bulbs Spectrum is confined to approximately less than 7 KHz

9. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 9 Fluorescent Tubes Spectrum is confined to approximately less than 3 KHz (the 48” tube has a very clean spectrum)

10. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 10 We did not test with an inverter fluorescent lamp. The highest spectral components we observed fall within frequency range 1. It would be useful to have more information about interference sources that generate significant energy above 40 KHz. How would inverter fluorescent lamps be deployed in VLC environments? From doc 08/0061-02 …

11. doc.: IEEE 802.15-09-0136-00-0007 Submission March 2009 Rick Roberts (Intel)Slide 11 Conclusions Other then for the dimmable CFL, the spectrum of the detected interference light is <10 KHz. If the dimmable CFL is included then the spectrum extends up to about 22 KHz under certain dimming conditions.