March 2006 Slide 1 doc.: IEEE /138r0 Submission DRAFT - I Project: IEEE P Working Group for Wireless Personal Area Networks Submission Title: [RF Exposure Rule Under Part ] Date Submitted: [March 2006] Source: [Gary Baldwin, SiBEAM, Freemont, CA] [Abbie Mathew, NewLANS, Westford, MA] [Abbie Mathew, NewLANS, Westford, MA] [Kamran Sayrafian, NIST, Gaithersburg, MD] [Kamran Sayrafian, NIST, Gaithersburg, MD] Re: [] Abstract: [] Purpose:[Contribution to TG3c at March 2006 plenary in Denver] Notice:This document has been prepared to assist the IEEE P 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 P

March 2006 Slide 2 doc.: IEEE /138r0 Submission DRAFT - I Top Level Document Flow Chart §1.1307(b) Compliance Actions § Radiation Exposure §15.255(g) RF Radiation Exposure § Mobile Device § Portable Device ANSI/IEEE C § Abbie Mathew, NewLANS

March 2006 Slide 3 doc.: IEEE /138r0 Submission DRAFT - I Top Level Document Flow Chart §1.1307(b) Compliance Actions § Radiation Exposure §15.255(g) RF Radiation Exposure § Mobile Device § Portable Device ANSI/IEEE C § Abbie Mathew, NewLANS (b)(1) (b)(2) (b)(3) (b)(3)(i) (b)(3)(ii) (b)(4) (a) (b) (c) (d) (d)(1) (d)(2) (d)(3) (d)(4) (a) (b) (c) (d) (d)(1) (d)(2) (d)(3) (d)(4)

March 2006 Slide 4 doc.: IEEE /138r0 Submission DRAFT - I Review of Part Rules 2. Limits on Human Exposure to RF Emissions 1. Limits on Emission  Average power density ≤ 9  W/cm 2 at 3 m Translates to EIRP of 40 dBm in the far field  Peak power density ≤ 18  W/cm 2 at 3 m Translates to an EIRP of 43 dBm in the far field  Total peak transmitter power ≤ 500 mW 3 m is in the far field for small apertures  Information contained in OET Bulletin 65  Enables an applicant to make a reasonably quick determination as to whether a proposed or existing facility is in compliance with the limits 3. Transmitter Identification  Within any 1 second interval of signal transmission, each transmitter must transmit a transmitter identification at least Abbie Mathew, NewLANS

March 2006 Slide 5 doc.: IEEE /138r0 Submission DRAFT - I Mobile & Portable Devices § & § MobilePortable Definition §2.1091(b) Transmitting devices where the antenna is at least 20 cm from the user §2.1093(b) Transmitting devices where the antenna is within 20 cm from the body of the user Certification §2.1091(c), §1.1307(b)(2) §2.1093(c), §1.1307(b)(2) Require RF exposure evaluation prior to equipment certification Abbie Mathew, NewLANS

March 2006 Slide 6 doc.: IEEE /138r0 Submission DRAFT - I Mobile & Portable Devices § & § MobilePortable Warning Label (Controlled Exposure) §2.1091(d) Compliance with exposure guidelines can be accomplished by the use of warning labels and by providing users with information on minimum separation distance §2.1093(d)(1) Awareness of exposure can be accomplished by use of warning labels or by specific training or education through appropriate means, such as an RF safety program in a work environment. Warning Label (Uncontrolled Exposure) Same as above §2.1093(d)(2) Not Permitted Abbie Mathew, NewLANS Note For mobile devices, warning labels can be used for controlled and uncontrolled exposures

March 2006 Slide 7 doc.: IEEE /138r0 Submission DRAFT - I Mobile & Portable Devices § & § Unclear Distinction If the device usage does not allow easy classification as either mobile or portable then applicants are responsible for determining minimum distances for compliance for the intended use and installation of the device based on power density Abbie Mathew, NewLANS

March 2006 Slide 8 doc.: IEEE /138r0 Submission DRAFT - I Actions For Non-Compliance §1.1307(b)  If the radiator as specified in § and § is exceeded, then Environment Assessment (EA) has to be prepared  Applications or renewals for equipment authorization or modification must contain a statement confirming compliance with the limits in § and § §1.1307(b)(2) Require evaluation for RF exposure prior to equipment authorization or use as specified in §15.255(g) §1.1307(b)(3)(i) Applicant of previously compliant transmitters that are now non- compliant with limits in § must submit an Environment Assessment (EA) if power density emissions exceeds 5% of the exposure limit §1.1307(b)(3)(ii) Renewal applicant of previously compliant transmitter that are now non-compliant with limits in § must submit an Environment Assessment (EA) if power density emissions exceeds 5% of the exposure limit Abbie Mathew, NewLANS

March 2006 Slide 9 doc.: IEEE /138r0 Submission DRAFT - I Definitions  Occupational/Controlled Exposure Work related or transient in natureWork related or transient in nature Person must be fully aware of exposurePerson must be fully aware of exposure Person must have knowledge to control and limit exposurePerson must have knowledge to control and limit exposure Require RF exposure trainingRequire RF exposure training High exposure limits applyHigh exposure limits apply Abbie Mathew, NewLANS  General Population/Uncontrolled Exposure Apply to all consumer devicesApply to all consumer devices No knowledge of exposure is requiredNo knowledge of exposure is required More restrictive exposure limits applyMore restrictive exposure limits apply

March 2006 Slide 10 doc.: IEEE /138r0 Submission DRAFT - I Definitions Abbie Mathew, NewLANS  Maximum Permissible Exposure (MPE): The plane- wave equivalent power density to which a person may be exposed without harmful effect and with an acceptable safety factor  Power density: Power per unit area normal to the direction of propagation, expressed in mW/cm 2 or μW/cm 2

March 2006 Slide 11 doc.: IEEE /138r0 Submission DRAFT - I Absolute MPE Limits for Different Frequencies Abbie Mathew, NewLANS

March 2006 Slide 12 doc.: IEEE /138r0 Submission DRAFT - I Spatial Averaging  These exposure guidelines apply to power densities that are spatially averaged over the body dimensions*  Local values of exposures that exceed the stated MPEs may not be related to non-compliance if the spatial average of RF fields over the body does not exceed the MPEs  Further discussion of spatial averaging as it relates to field measurements can be found in OET-65 and in the ANSI/IEEE and NCRP reference documents Kamran Sayrafian, NIST * This information is as of March Spatial averaging window size is under active rulemaking process. Please direct further inquiries to FCC

March 2006 Slide 13 doc.: IEEE /138r0 Submission DRAFT - I Partial Body Exposure  Partial-body exposure results when RF fields are substantially non-uniform over the body  Fields that are non-uniform over volumes comparable to the human body may occur due to highly directional sources, standing-waves, re-radiating sources or in the near field  Limits for localized absorption are based on recommendations of both ANSI/IEEE and NCRP Kamran Sayrafian, NIST

March 2006 Slide 14 doc.: IEEE /138r0 Submission DRAFT - I Temporal Averaging  Exposures, in terms of power density, may be averaged over certain periods of time with the average not to exceed the limit for continuous exposure  FCC has not explicitly adopted limits for peak power density (guidance on these types of exposures can be found in Section 4.4 of the ANSI/IEEE C standard) Kamran Sayrafian, NIST Average (Temporal) Power The time-averaged rate of energy transfer Averaging Time The appropriate time period over which exposure is averaged for purposes of determining compliance with RF exposure limits. Continuous Exposure Exposure for durations exceeding the corresponding averaging time

March 2006 Slide 15 doc.: IEEE /138r0 Submission DRAFT - I Time-Averaged MPE Limits § Frequency(GHz) Power Density (mW/cm 2 ) Averaging Time (minutes) Controlled Exposures 1.5 to Uncontrolled Exposures 130 Controlled exposure applies in situation where a person is exposed as a consequence of his employment, provided he is fully aware of and can exercise control over his exposure. Uncontrolled exposure applies in situation where the general public may be exposed, or when a person is exposed as a consequence of employment may not be fully aware of the potential for exposure or cannot exercise control over his exposure. Kamran Sayrafian, NIST

March 2006 Slide 16 doc.: IEEE /138r0 Submission DRAFT - I Time-Averaged MPE Limits In general, the sum of the products of the exposure levels and the allowed times for exposure must equal the product of the appropriate MPE limit and the appropriate time-averaging interval Kamran Sayrafian, NIST S exp = power density level of exposure (mW/cm 2 ) S limit = appropriate power density MPE limit (mW/cm 2 ) T exp = allowable time of exposure (minutes) T avg = appropriate MPE averaging time (minutes) where

March 2006 Slide 17 doc.: IEEE /138r0 Submission DRAFT - I Time Averaging MPE limits adopted by the FCC are time-averaged exposure limits MPE limits adopted by the FCC are time-averaged exposure limits This means that the exposure duration should be taken into account This means that the exposure duration should be taken into account Especially relevant for cases of occupational/controlled exposure Especially relevant for cases of occupational/controlled exposure Example The relevant interval for time-averaging for occupational/controlled exposures is six minutes as shown below Kamran Sayrafian, NIST 30 mW-min/cm 2 time 6 min (Sliding Window) 5 mW/cm 2

March 2006 Slide 18 doc.: IEEE /138r0 Submission DRAFT - I Time Averaging Example for Controlled Environments During any given six-minute period a worker could be exposed to two times the applicable power density limit for three minutes as long as he or she were not exposed at all for the preceding or following three minutes orDuring any given six-minute period a worker could be exposed to two times the applicable power density limit for three minutes as long as he or she were not exposed at all for the preceding or following three minutes or He/She could be exposed at three times the limit for two minutes as long as no exposure occurs during the preceding or subsequent four minutes, and so forth.He/She could be exposed at three times the limit for two minutes as long as no exposure occurs during the preceding or subsequent four minutes, and so forth. time 6 min 10 mW/cm 2 15 mW/cm 2 3 min 6 min 30 mW- min/cm 2 Kamran Sayrafian, NIST

March 2006 Slide 19 doc.: IEEE /138r0 Submission DRAFT - I Time Averaging Provision For General Population/Uncontrolled Environments For devices intended for use by consumers in general population/uncontrolled environments time-averaging provisions may not be used in determining typical exposure levels (§2.1091(d)(2)). However, source-based’ time-averaging based on an inherent property or duty cycle of a device is allowed.For devices intended for use by consumers in general population/uncontrolled environments time-averaging provisions may not be used in determining typical exposure levels (§2.1091(d)(2)). However, source-based’ time-averaging based on an inherent property or duty cycle of a device is allowed. Kamran Sayrafian, NIST In contrast to "user-based" or “activity-based”, source-based time- averaging does not consider user behavior when calculating the time- average. For example, it cannot be assumed that users will step in/out of exposure for certain periods of time.

March 2006 Slide 20 doc.: IEEE /138r0 Submission DRAFT - I Source-Based Time Averaging  Example for source-based time-averaging is the determination of exposure from device that uses digital technology such as a time-division multiple access (TDMA) scheme for transmission of a signal. In general, maximum average power levels must be used to determine compliance.  e.g. A GSM handset can transmit in one out of eight possible time slots. This is an inherent property of the source and it does not depend on the user behavior. Kamran Sayrafian, NIST

March 2006 Slide 21 doc.: IEEE /138r0 Submission DRAFT - I IEEE Perspective Recommendation to prevent harmful effects in human beings exposed to electromagnetic fields in the frequency range from 3 KHz to 300 GHzRecommendation to prevent harmful effects in human beings exposed to electromagnetic fields in the frequency range from 3 KHz to 300 GHz Apply to exposures in controlled as well as uncontrolled environmentsApply to exposures in controlled as well as uncontrolled environments Kamran Sayrafian, NIST IEEE Standard C95.1, 1999 Edition

March 2006 Slide 22 doc.: IEEE /138r0 Submission DRAFT - I MPE Limits (Controlled & Uncontrolled Environments) Frequency Range (MHz) Power Density (S) E-field, H-field (mW/cm 2 ) Averaging Time |E| 2, |H| 2 or S (min) / f 1.2 * Note: f is the frequency in MHz. Also, the averaging time window size is subject to change in the upcoming IEEE draft For the frequency of 60GHz, the averaging time is approximately minutes Kamran Sayrafian, NIST * This information is as of March 2006

March 2006 Slide 23 doc.: IEEE /138r0 Submission DRAFT - I Partial Body Exposures Kamran Sayrafian, NIST Compliance for the MPE is determined from spatial averages of power density over an area equivalent to the vertical cross-section of the human body (projected area) at a distance no closer than 20 cm from any object *. For partial body exposure (i.e. all parts except the eyes and the testes), limits on the peak value of the power density exist. * This information is as of March Spatial averaging window size is subject to change in the upcoming IEEE draft

March 2006 Slide 24 doc.: IEEE /138r0 Submission DRAFT - I Maximum Peak Value of the Mean Squared Field Strength Kamran Sayrafian, NIST Maximum Peak value of the mean squared field strength For f = 60 GHz Controlled Environments 20(f/6) 1/4 mW/cm 2 for frequencies between 6 and 96 GHz mW/cm 2 Uncontrolled Environments 20 mW/cm 2 for frequencies above 30 GHz 20 mW/cm 2

March 2006 Slide 25 doc.: IEEE /138r0 Submission DRAFT - I Summary (as of March 2006!) Kamran Sayrafian, NIST FCC GuidelinesIEEE Guidelines ControlledUncontrolledControlledUncontrolled Absolute MPE (mW/cm 2 ) 5110 Averaging Time (min) Limit on the Temporal Peak (mW/cm 2 ) None See Section Parts f & g See Section parts f & g Limit on the Spatial Peak (mW/cm 2 ) None (Only for partial body exposure) 20 1 (Only for partial body exposure) 1 These numbers are as of March Please watch for possible changes in the upcoming IEEE draft 2 This information is as of March Spatial averaging window size is under active rulemaking process. Please direct further inquiries to FCC

March 2006 Slide 26 doc.: IEEE /138r0 Submission DRAFT - I Acknowledgement We would like to express our gratitude to Mr. Ed Mantiply (from the Federal Communications Commission) for his time in answering our questions and his review of the materials in this presentation. Kamran Sayrafian, NIST