EMF compliance assessment of radio base stationsDAVIDE COLOMBI, ERICSSON RESEARCH

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 2

outline

› Overview of EMF RBS requirements and standards› EMF compliance testing of RBS products› Research topics› Realistic exposure › Conclusions

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 3

Place on the market

EMF COMPLIANCE OF RBS

› ITU-T (Adopted mainly developing countries)– ITU-T K.52– ITU-T K.61– ITU-T K.70

› IEC 62232– 1st ed. published 2012, currently in maintenance phase

› CENELEC (Europe)– EN 50383/50384/50385 for place on the market of RBS– EN 50400/50401 for put into service of RBS

› Some countries have adopted their own regulation

International standards providing guidance and requirements on assessment of EMF

compliance of RBS

- Product compliance- Laboratory-based

- Put into operation - “Site” compliance

Put into service

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 4

place on the market assessments

› Why? Provide information about EMF exposure to the user of the product

› How? Determine compliance boundary (CB), i.e. area outside of which the EMF exposure is below the limit

› By means of? Calculations or measurements of SAR / field strengths

Ambient sources and scatterers are not considered RBS

Antenna

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 5

macro rbs

› Field-strength simulations are typically used to assess compliance with reference levels

– Accurate and cost-effective– RBS antennas are relatively easy to model– Excellent agreement with measurements

Antenna models are based on the design of

real RBS antennas

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 6

compliance boundary for macro rbs

Frequency: 2100 MHzGain: 18 dBi

Dimension: 1314 x 155 x 70 mm

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 7

pico and micro rbs

› Whole-body SAR measurements standardization is ongoing Available power

1-10 W

› Compliance distance from 10 to 100 cm› SAR measurements used for small

standalone equipment– Power < 1 W only localized SAR (EN 50383)– Power > 1 W localized SAR + spatially averaged

field strength

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 8

research topics› Fast whole-body

SAR measurements method

› MIMO antennas

› mm wave communications

surface scan

propagationalgorithm

prototype, 60 GHz

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 9

maximum vs realistic exposure

› EMF compliance testing of RBS is conducted assuming constant transmission at the maximum power

› The actual transmitted power

may be significantly below the maximum

Network data collected for more than 5000

RBS in Sweden

RMS Downlink Power (normalized to maximum)

RBS compliance assessments are not

representative of the realistic exposure conditions

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 10

Effects of using arbitrary emf limits

ICNIRP limits61 V/m

compliance distance 6 m

Belgium limits3 V/m

compliance distance 100 m

1 antenna, WCDMA 2100 MHz, 80 watt output power

ITU Workshop on Human Exposure to Electromagnetic Fields (EMFs), Turin, Italy, 9 May 2013 | © Ericsson AB 2013 | Page 11

Conclusions

› EMF compliance testing of RBS products is conducted before placing on the market and putting into service

› Place on the market testing of RBS includes determining the compliance boundary

– 1 m to 6 m in the main beam direction for macro RBS antenna – 10 cm to 100 cm for small cell RBS products

› RBS compliance assessment is not representative of the realistic exposure condition