Near Field Communications

Článek
11/05/2020

Required, recommended, and optional near field proximity features

This topic covers recommendations for near field communications (NFC) in Windows 10. The following table lists required, recommended, and optional near field proximity features.

Feature	Remarks
Bus	Refer to Hardware Configurations. SPB API support using I²C, SPI or UART
Antenna	Antenna dimensions can vary, as long as the effective actuation successfully connects at a range of 0 cm to 2 cm, is allowed but not required to connect at a range of 2 cm to 10 cm, and is prohibited to connect at a range greater than 10 cm (required). An antenna dimension of 40 mm x 60 mm is known to best achieve these results, but other configurations are acceptable as long as they meet the range of actuation requirements that enable the Windows scenarios (recommended). An antenna should be placed according to form factor along with the official NFC Forum N-Mark to indicate antenna location.
Implementation	Compliant with the guidance in NFC Design Guide (required).
Reliability	[NFP] 95% success rate without errors based on 100 consecutive session attempts with 5 second intervals (required). [Smart Card Reader] 95% success rate without errors based on 100 consecutive connection attempts with 5 second intervals (required). [HCE] 95% success rate without errors based on 100 consecutive connection attempts with 5 second intervals (required). [UICC] 95% success rate without errors based on 100 consecutive connection attempts with 5 second intervals (required).
Near field proximity	Near Field Communication defined by NFC Forum (required). A NFP provider must support the creation of sessions within 0.5 seconds from the point of being detected within the effective operating volume (required).
PC/SC Smart Card Reader	Required feature on all platforms.
Radio Manager	Required feature on all platforms. Must implement the interface to match the defined commands from the Microsoft NFC Radio Manager.
Host Card Emulation (HCE)	Required on Windows 10 Mobile.
UICC Secure Element	This is an optional feature and is supported only on Windows 10 Mobile.

Hardware must comply with the Windows HLK requirements for near field proximity, including but not limited to accuracy, resolution, antenna placement, and range of values.

Firmware

Enumerate the device through ACPI.

Driver details

Near field proximity devices use IHV developed drivers. The drivers must comply with the guidance in Proximity Devices Design Guide. IHV developed drivers must pass the tests for validating near field proximity functionality such as the Windows HLK tests.

Mechanical

Antenna placement is critical for providing the best user experience and providing a consistent tap interaction between devices. Adding the NFC Forum’s N-Mark on the device so the user knows where to tap devices together helps users discover and align the antenna, helping them complete the scenarios in the intended way. Additionally, Windows provides sound feedback during the Tap and Do experience.

The table below describes the location for the antenna by form factor.

Form Factor	Antenna Location and Considerations
Tablet	Place the NFC loop antenna near the surface of the device, not in the middle, with proper shielding to insure sufficient actuation volume (required). Place in the upper right-hand quadrant seen from the user holding the device to support the most natural interaction (recommended).
Convertible	Please use your best sense of judgement for convertible style systems.
Clamshell	Place the NFC loop antenna to the right of the touch pad, under the touch pad or under the right palm rest with proper shielding to ensure sufficient actuation volume (recommended).
All-in-One	Place the NFC loop antenna on the front of device (for example, bezel area) (recommended).
Desktop	If you are placing the NFC loop antenna on the chassis for a desktop, we recommend that the loop be placed on the top of the chassis near the edge. It is preferable to include the NFC chip in the keyboard or provide an external USB dongle.