No recognised body has published a method for measuring whether a power beam meets the
\nexposure limits it must meet. One project was chartered to write it. That project has been
\nan Active PAR since June 2023, has no public draft, and its authorisation runs out in
\nDecember 2027.
\nThis matters more than it sounds. Everyone arguing about power beaming argues about the
\nlimit, and the limit is the settled part. What is missing is the boring half: where to put
\nthe probe, over what area to average, and what a regulator accepts as proof that the fence
\nis in the right place.
\nStart with the numbers, because they are documented and they are not controversial.
\nICNIRP's 2020 radiofrequency guidelines set a general public whole-body reference level of
\n10 W/m² incident power density between 2 and 300 GHz, averaged over 30 minutes, and 50 W/m²
\nfor occupational exposure. IEEE Std C95.1-2019 is the second document to cite. Read on
\n27 September 2026, its IEEE SA page gives it as an Active Standard, board approval
\n8 February 2019, published 4 October 2019, with Cor 1-2019 and Cor 2-2020 as the only
\ncorrigenda and the working group showing "No Active Projects".
\nThose documents tell you the number. They do not tell you how to obtain it in the field.
\nThey do not say what area to spatially average over when the field varies across the width
\nof a person, what to do about a 30-minute averaging time when the field is steady and the
\nperson is not, what instrument to use, at what height, or with what uncertainty budget.
\nIEEE Std C95.3-2021 is the general answer to that question and is deliberately not a
\nprocedure. Its IEEE SA page gives board approval 25 March 2021 and publication 28 May 2021,
\nand the scope says plainly that detailed methodology is not described: best practice is
\nexpressed through guidance and references to other documents. That is the right document
\nfor a specialist and the wrong one to attach to a licence application.
\nThe document that does give procedures is IEC 62232, fourth edition, published 29 April 2025
\nby IEC TC 106 and titled "Determination of RF field strength, power density and SAR in the
\nvicinity of base stations for the purpose of evaluating human exposure". It covers 110 MHz
\nto 300 GHz for intentional transmissions, it distinguishes product compliance boundaries
\nfrom installation compliance and in-situ measurement, and it handles time-varying
\nbeam-steering including massive MIMO. Every piece of that is close to what a power beaming
\nsite needs. None of it is scoped to a transmitter whose purpose is to deliver power, and a
\nrectenna field is not a base station.
\nIEEE P63480 is the project. Its IEEE SA page, read on 27 September 2026, gives the title as
\n"Assessment of Human Exposure to Electromagnetic Fields from Radiative Wireless Power
\nTransfer Systems: Measurement and Computational Methods", for the frequency range 30 MHz to
\n300 GHz. Status: Active PAR. PAR approval date: 29 June 2023. Sponsor: the IEEE SA Board of
\nGovernors through ICES, the International Committee on Electromagnetic Safety. Working group
\nchair: Andreas Christ. The scope covers incident field strength, incident power density,
\nspecific absorption rate and absorbed power density, from the reactive near field out to the
\nfar field.
\nThe page shows no draft, no ballot state and no publication date. It has shown none on every
\nreading this project's daily scan has made since 30 August 2026.
\nOne honest caveat before that is over-read. IEEE drafts are not public before ballot, so the
\nabsence of a visible draft is not proof that nobody is writing one. What is public, and what
\nis checkable, is the clock.
\nThe IEEE SA Standards Board New Standards Committee recommendations carrying SASB approval
\ndate 29 June 2023 list P63480 under ICES among the new PARs, with the recommendation
\n"Approve new PAR until December 2027." The IEEE SA Standards Board Operations Manual,
\nclause 5.2, sets the rest: a project not completed by the four-year deadline authorised in
\nthe PAR needs the Standards Committee to file an extension request with NesCom, which may be
\ngranted for one or more years, and a project that reaches its deadline without one "shall be
\nsubject to administrative withdrawal".
\nFifteen months, from today, on the authorisation as originally granted. Two limits on that
\nsentence. The project page publishes no expiry date, and searches of published NesCom
\npapers did not surface an extension for P63480 in either direction. If an extension has been
\ngranted since 2023, it is not visible on the pages checked here.
\nThe gap is not a failure of the machinery, and the evidence is that the machinery already
\ndelivered the adjacent standard. IEC/IEEE 63184:2025 was published on 25 February 2025 by
\nIEC TC 106, titled "Assessment methods of the human exposure to electric and magnetic fields
\nfrom wireless power transfer systems", covering models, instrumentation, measurement and
\ncomputational methods for the range 3 kHz to 30 MHz. It handles SAR, internal electric
\nfields and contact currents, and it is aimed at inductive systems.
\nThat is the low-frequency, near-field half of exposure assessment for wireless power, it is
\nfinished, and it carries both logos. So the joint IEC and IEEE route works, and the people
\nwho know how to write these documents are in the room.
\nThe half that is missing is precisely the half power beaming needs. The most likely reading
\nis not competence but priority. The market behind 63184 is electric vehicle and consumer
\ncharging, shipping in the millions of units, with manufacturers who need a compliance test
\ntoday. The market behind 63480 is a small number of funded demonstrations. Standards follow
\nunits, and there are no units yet.
\nPut rough numbers on the thing being measured. What follows is estimated, and it is
\narithmetic on a hypothetical rather than anybody's published system.
\nTake a transmitting aperture 1 km across in geostationary orbit at 5.8 GHz. Before going
\nfurther: 5.8 GHz is not regulatorily available for space-to-Earth power transmission. It is
\nthe band the engineering literature uses, it sits in an ISM allocation intended for
\nindustrial, scientific and medical use, and using it in a study is not permission to radiate
\nfrom orbit.
\nAt a 5.17 cm wavelength over 35,786 km, the first-null main lobe from a 1 km aperture is
\nroughly 2.44 λR/D, which is about 4.5 km across. Spread a radiated gigawatt across that, and
\nthe average is around 60 W/m², with an on-axis peak perhaps twice that under a tapered
\nillumination. Both figures are estimates. Radiated is not delivered, and neither number is a
\nrating of any real machine.
\nAgainst a general public reference level of 10 W/m², the consequence is geometric. The
\nboundary of the publicly accessible area is a flux contour lying a kilometre or so outside
\nthe nominal spot, and where exactly it lies depends on the aperture taper, the pointing
\nerror and the atmosphere on the day. That contour is the fence. It is also a site's largest
\nland cost and its licence condition.
\nNow ask the questions the limit does not answer. Over what area is the average taken. What
\ncounts as compliance for a person crossing the contour for two minutes rather than thirty.
\nWho measures it, with what instrument, traceable to what, and what uncertainty does the
\nregulator accept. Those are exactly the questions P63480 was chartered to answer. Until it
\nlands, every demonstration negotiates its own method with its own regulator, and every one
\nof those negotiations sets a precedent that no committee voted on.
\nThe ITU side does not fill the gap either. The in-force Recommendation ITU-R SM.2151-0
\n(09/2022) is titled "Guidance on frequency ranges for operation of wireless power
\ntransmission via radio frequency beam for mobile/portable devices and sensor networks",
\nwhich is its scope as well as its title. WRC-31 preliminary agenda item 2.2, under
\nResolution 910 (WRC-23) and led by Working Party 1A, reads "to consider the possible
\n[frequency bands] for [non-beam and beam] wireless power transmission to avoid harmful
\ninterference to the radiocommunication services", brackets in the original. That is
\ninterference between services, not human exposure, and it is not yet agreed text.
\nA public draft or a ballot state appearing on the P63480 project page would change the
\nstrongest sentence here immediately, and I would say so.
\nA NesCom record extending the PAR past December 2027 would change the framing even without a
\ndraft, because it would show a committee that intends to finish rather than one drifting
\ninto administrative withdrawal. That record is the single piece of evidence this article
\nmost wants and does not have.
\nThe IEC side is unchecked and could contradict me. The IEC TC 106 project dashboard returned
\nHTTP 403 to this run, so the IEC-side stage for 63480 was not read. If it shows a committee
\ndraft in circulation, then "no draft in three years" is wrong as written and should be
\nretracted rather than softened.
\nA regulator publishing guidance that extends IEC 62232's base-station procedures to power
\nbeaming would close the gap in practice without any new standard. That would be the quiet
\noutcome, and it is plausible, because it is what regulators usually do.
\nWhat would not change my mind is another funded demonstration, another award, or another
\ncompany announcing a megawatt of anything. Money is not a method, and a compliance
\ndemonstration that cannot be repeated by a second party with published procedures is a
\nprivate arrangement wearing a standard's clothes.
\n