Chapter 7
The earlier phases of WIA-COMM-009 define what a wireless-power-transfer (WPT) message looks like, how it is exposed over HTTPS, and how it moves across trust boundaries. Phase 4 asks a different question: once a transmitter is bolted to a kerb, a wall, a rooftop or a lamp post, whose rules does it have to satisfy? The specification itself titles this phase "Integration", and its subtitle names the ecosystem it must integrate with: WPC, AirFuel, SAE, IEC, ICNIRP, IEC 60825-1 and ITU-R. In this book's numbering the phase is presented as optimization, meaning the tuning of a deployment against the surrounding rule-makers and operators rather than the redesign of its internals.
WPT is an unusual product category because one installation wears several hats at once. It is a power converter, an intentional or incidental radio emitter, a source of human exposure to electric and magnetic fields, and, in the beamed variants, possibly a laser product. Each hat belongs to a different regulator and a different standards family. Phase 4 therefore reads less like a protocol description and more like a map that tells an integrator which authority owns which question.
The specification body covers inductive (IPT), capacitive (CPT), resonant, microwave and laser transfer, plus EV charging and space solar power. Phase 4 pins each family to the standards that govern it in practice. The table below condenses the cross-walk the specification provides. It is informative only, and implementers are expected to obtain the authoritative texts from the issuing bodies.
| Technology family | Primary anchors | Typical regulatory concern |
|---|---|---|
| Low-power consumer inductive | WPC Qi v1.3 / v2.0 (cross-reference WIA-COMM-008), IEC 62368-1 | Interoperability between pads and phones; charger safety |
| Resonant consumer | AirFuel Alliance specifications | Spatial freedom, emissions, exposure |
| EV static charging | SAE J2954, SAE J2847/6, IEC 61980-1/-2/-3, ISO 19363 | Ground-to-vehicle alignment, communications, safety, interoperability |
| Microwave beaming | ITU-R Radio Regulations, FCC 47 CFR Part 15 / Part 18, national licences | Spectrum allocation, licensed power and steering envelope |
| Laser beaming | IEC 60825-1, national laser-product regimes | Laser class, occupational exposure |
The practical value of the table is that no single row is sufficient. A wireless charging pad for a phone still needs EMC compliance, and an EV pad still falls under radio-frequency and human-exposure rules. The rows therefore describe the first place to look, and the horizontal rules in the sections that follow (EMC, RF, EMF, implantable devices) apply to nearly all of them.
Each integration point in Phase 4 can be traced to a physical property of the energy path. Three of those properties account for most of the standards that appear in the cross-walk.
Fields leak. A magnetic-coupling system such as Qi, an AirFuel resonant link or an EV ground pad concentrates energy between coil and coil, but the surrounding space is never field-free. That is why the specification brings in emissions and immunity standards: CISPR 11 for industrial, scientific and medical equipment, CISPR 25 for vehicle environments, EN 301 489 for radio equipment EMC and the IEC 61000-4 series for immunity. In the EU, short-range device rules such as ETSI EN 300 330 and the RED Directive 2014/53/EU apply. In the US the corresponding frameworks are FCC 47 CFR Part 15 and Part 18. The Kurs et al. 2007 demonstration of strongly coupled magnetic resonances, cited in the specification's technical literature, is the foundation for mid-range resonant designs, and it is also the reason spatial freedom and field containment trade off against each other.
Bodies are in the field. Human exposure is judged against ICNIRP guidance (the 2010 and 2020 editions are cited) and IEEE C95.1-2019. ICNIRP's guidelines use basic restrictions together with reference levels at the operating frequency, and the specification carries this distinction through to its occupational-exposure language. Implanted devices add a second concern, because a pacemaker responds to fields at levels that are harmless to tissue. The specification points to ISO 14117, which addresses electromagnetic compatibility of active implantable medical devices, and notes that regulators in several jurisdictions publish equivalent guidance.
The atmosphere takes its share. For beamed power, free-space propagation is only part of the loss budget. The ITU-R P.676 and P.838 models, which cover gaseous attenuation and rain attenuation respectively, feed any estimate of how much microwave power reaches a rectenna in realistic weather. Phased-array beam control, as discussed in Shinohara's work on microwave power transmission, and the lunar-polar laser beaming studies by Landis show that these links are engineered around the path rather than the endpoints. Laser links are additionally governed by IEC 60825-1, and the specification's position is blunt: public laser beaming above Class 1 is outside what it certifies.
One more technical layer sits above the physics: communications between the vehicle and the ground assembly. SAE J2847/6 is listed as the EV WPT communications standard. For the conductive side of the charging ecosystem, which the specification cross-references rather than replaces, IEC 61851, SAE J1772 and ISO 15118 appear in the reference list. A wireless charging station is therefore not isolated from plug-in infrastructure. It shares back-office and grid-facing behaviour with it.
The specification does not publish market sizing, and this chapter does not supply any. The structure of the ecosystem is visible from the standards alone, however. At the consumer end, Qi and AirFuel are the two named families, with Qi handled in the sibling standard WIA-COMM-008 so that WIA-COMM-009 can concentrate on the broader landscape. In the vehicle segment, SAE (North America), IEC (Europe) and ISO (the safety and interoperability work in ISO 19363) have each built partly overlapping documents, which creates a real obligation for products sold across regions to demonstrate more than one compliance path.
At the experimental end, the picture reverses. Microwave and laser beaming are governed by licences granted to specific operators for specific sites, not by product certificates. The specification states that commercial space-solar-power, public laser beaming above Class 1 and megawatt-class microwave-beaming services remain research-track only, and it does not certify them. For a reader sizing an opportunity, that line separates what can be certified and deployed today from what remains a laboratory or licensed-trial activity.
Two application areas need the most integration work: EV charging networks and licensed beaming installations. They are opposite in character, since the first is a commodity roll-out and the second is a case-by-case authorisation, but both are described by Phase 4 as bundles of envelopes that capture what an operator must declare.
For EV charging, the per-station envelope records the installation type (street-side, parking-lot or depot), the meter of record, and how users are authenticated (RFID, NFC, an app or a vehicle credential). Back-office billing is handled through OCPP 2.0.1 from the Open Charge Alliance. Grid-side coordination goes through load-management mechanisms, namely IEC 61851, SAE J3072 and ISO 15118 plug-and-charge. Where the site supports energy flowing back to the grid, a bidirectional V2G envelope applies. The vehicle-side receiver is cross-referenced to WIA-AUTO-021 for the receiver-of-record envelope. The design choice worth noting is that a wireless pad is treated as a first-class charge point in existing billing and grid frameworks rather than as a special case outside them.
For microwave beaming, the integration envelope captures the operator's licence under the relevant national regulator. The specification names FCC Experimental plus Part 18 for ISM-band operation in the US, an Ofcom 28 GHz industrial-test arrangement in the UK, and equivalents at BNetzA (Germany), ANFR (France), KCC (Korea), MIC (Japan) and MIIT (China). A condensed outline of what that envelope records:
Microwave-beaming integration envelope (outline of contents)
- licensed frequency
- licensed Tx power and beam-steering envelope
- deployment-site approval
- post-licensing compliance-monitoring envelope
- renewal-and-reporting cadence
Laser-beaming addition
- laser-class licensing under the operator's national regime
(US FDA CDRH; EU Directive 2006/25/EC; KR Radiation Health Act)
This is a summary of what the envelope covers, not a schema listing. The point is that a beaming operator's licence, power ceiling, steering limits, site approval and reporting duties travel together in one record. A reviewer or auditor can then see at once whether the beam being steered is the beam that was licensed.
Safety rules for WPT are local even when the physics is universal. The specification therefore expects an integration to honour the exposure rules of each jurisdiction in which it operates. For EMF and laser exposure these include ICNIRP, FCC OET 65, EU Directive 2013/35/EU on workplace EMF, and Korean RAC standards. For implantable-device interaction the cross-walk is ISO 14117 together with guidance from the FDA, the Korean regulator, PMDA and NMPA. For workers, the occupational framework applies ICNIRP's basic restrictions and reference levels at the operating frequency. Public-facing systems carry an EMF test report issued by an accredited laboratory under ISO/IEC 17025, so the evidence has an identifiable, independent author.
The following selection from the cross-walk shows how different problems pull from different documents:
A single paragraph covers the specification's process side. The reference suite, a conformance test project, exercises every endpoint and protocol exchange, and a mock-data container lets integrators try the contract before connecting real backends. Within the 1.x line, existing envelopes, endpoints and exchanges must remain reachable. Hosts may add optional fields but must not remove existing ones, and a breaking change requires a major version with a 12-month deprecation window. For an integrator this means the regulatory mapping in this chapter will not be invalidated by minor releases.
Most integration effort is spent on matters that no schema captures, such as site conditions, lead times and evidence gathering. The following points recur across the families discussed above.
The specification lists active research tracks that indicate where integration will become harder. Several combine existing families. Multi-frequency cooperative systems use inductive transfer for high power and resonant transfer for spatial freedom, and cooperative-multipoint designs have several ground transmitters collaborate to feed a moving vehicle. Others extend reach: beamformed RF that delivers ambient power to several devices in a room, laser power for BVLOS UAS recharging in flight, and satellite-to-Earth beaming at multi-megawatt scale. Further tracks cover bidirectional V2G over a resonant link and ultra-thin metasurface receivers embedded in walls and floors.
Each of these tracks stretches an existing regime. Moving receivers complicate alignment and exposure assessment. Airborne laser charging raises questions the laser-class framework was not written for. Embedded receivers blur the line between building infrastructure and a radio device. The specification routes such proposals through its roadmap interface (POST /standards/v1/proposals) and the WIA Committee voting process, which keeps them visible without granting them certification status.
Phase 4 turns a technically sound WPT system into a deployable one by tying it to the regimes around it. The key moves in this chapter were as follows:
The next chapter carries this integration view into the closing material of the guide. There the standards, safety and EMC sources, technical literature and companion WIA resources that this chapter has repeatedly pointed to are gathered in one place, so readers can trace each claim back to the body that issued it.