Part 15 modules have two rf exposure categories - portable and mobile/ Simply put, portable rf category is classified as any thing within 20cm of the body and mobile is anything 20cm or further from the body.
Any portable device approved as a module has a power limitation depending on the frequency of operation at which SAR would be required. Below this power SAR is not required and the device can be used in any host. Above this power and SAR must be done inside a host. Again, depending on the power, SAR may have to be done in or host of each type or in three hosts of each type. If you cannot maintain the 20cm compliance of a product it will automatically fall into the portable rf exposure category and you will have to determine if SAR is applicable. This is also dependent not only on the antenna conducted power but on the EIRP power. Both, not just one or the other, must be lower than the limit for SAR requirements. Dennis Ward Evaluation Engineer American TCB Certification Resource for the Wireless Industry www.atcb.com 703-847-4700 fax 703-847-6888 direct - 703-880-4841 cell - 209-769-8316 NOTICE: This E-Mail message and any attachment may contain privileged or company proprietary information. If you received this message in error, please return to the sender. From: [email protected] [mailto:[email protected]] On Behalf Of Jim Eichner Sent: 04/28/2006 1:25 PM To: [email protected] Subject: Embedding WiFi into a non-radio product - FCC 20cm rule We are looking at embedding an 802.11 transmitter into a product. The transmitter has an FCC limited modular approval and one stipulation of that approval is that steps must be taken to ensure the user cannot come within 20cm of the antenna. I am being told that the 20cm is measured >from any part of the user's body and that this is a firm requirement. >From what I can tell, most (all?) modular approvals have this limitation. For an end-product that will find use in homes, business, and industrial locations, ensuring this separation seems difficult if not impossible. The product is intended for wall mounting, and even at the very top of a wall or on the ceiling in a house tall people will be able to reach to within 20cm of the product. Are we really expected to restrict the installation such that it is not physically possible for someone to come within 20cm of the antenna?!? This isn't a laptop computer or a cell phone - nobody has any reason to be holding onto it, holding it against their head, or even be looking at its LED's for more than a few seconds. It seems to me to be overkill that it can't just sit on the wall like a thermostat for your furnace or the control panel for your home alarm. Maybe I wouldn't want it mounted on the wall right above the head of my daughter's crib, but surely there's a common sense compromise that is compliant? If not, is our only way out of this to do expensive SAR testing and prove that the 1mW/cm2 limit is met? Does anyone know if Zigbee also has this 20cm limitation? Thanks in advance, Jim Eichner, P.Eng. Compliance Engineering Manager Xantrex Technology Inc. e-mail: [email protected] web: www.xantrex.com Any opinions expressed are those of my invisible friend. Confidentiality Notice: This email message, including any attachments, is for the sole use of the intended recipient(s) and may contain confidential and privileged information. Any unauthorized review, use, disclosure or distribution is prohibited. If you are not the intended recipient, please contact the sender by reply e-mail and destroy all copies of the original message. - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc - This message is from the IEEE Product Safety Engineering Society emc-pstc discussion list. Website: http://www.ieee-pses.org/ To post a message to the list, send your e-mail to [email protected] Instructions: http://listserv.ieee.org/request/user-guide.html List rules: http://www.ieee-pses.org/listrules.html For help, send mail to the list administrators: Scott Douglas [email protected] Mike Cantwell [email protected] For policy questions, send mail to: Jim Bacher: [email protected] David Heald: [email protected] All emc-pstc postings are archived and searchable on the web at: http://www.ieeecommunities.org/emc-pstc
