Inside NCI 2.0 and What It Means for the New Generation of NFC Devices, Part 1
Several weeks ago, the NFC Forum released a new NFC Controller Interface (NCI) 2.0 candidate specification. Because NCI describes an internal interface between an NFC Controller and the main processor of an NFC-enabled device, it is not something most users of NFC devices need to – or probably care to –understand. But NCI version 2.0 includes several new features and functionality that both NFC developers and users of the next generation of NFC devices should be aware of. This is the first of two blog posts providing an overview of these new NCI features and what they mean for future NFC devices.
Extended Listen Mode Routing
Previous NCI versions included a Listen Mode Routing mechanism that enabled the Device Host to define rules on how to forward incoming radio frequency (RF) communication to the right entity (either to the Device Host or to a secure element directly connected to the NFC Controller). This mechanism is already used to allow the activation of RF applications installed on an NFC-enabled (U)SIM card in parallel with RF applications installed as apps on NFC-enabled mobile devices. That means the user can activate several RF applications in parallel on his or her mobile device after the installation of these RF applications.
When the user touches the mobile device to an RF reader, the reader automatically selects the right RF application. If the user activates, for example, one credit card RF application and one ticketing RF application at the same time, the credit card RF application will be used when the user brings the mobile device in front of a payment reader and the ticketing RF application will be used when the user brings the same device in front of an RF reader at a gate for public transport.
Why have we now extended this mechanism?
The first extension targets mobile devices having more than one secure element installed, since NFC-enabled devices with two or more (U)SIM card slots can contain more than one secure element with RF applications installed. Mobile devices with embedded secure elements can also have, together with the (U)SIM, two entities with RF applications. Concurrently with this extension, the NFC Forum is working closely with ETSI TC SCP and GlobalPlatform to align this evolution with the standardization bodies responsible for defining the interfaces for NFC-enabled secure elements.
The second extension allows the Device Host to define more specific rules at the NFC Controller to route incoming RF communications to the right entity. These additional rules are needed for some legacy RF applications based on older, single-application RF cards. As these RF applications did not consider NFC devices capable of providing multiple RF applications on the same device, it is quite difficult to detect these RF applications at the beginning of an RF session and to route the RF communication to the right entity. Therefore more rules were defined in NCI 2.0 to solve this problem.
The NDEF_NFCEE feature allows the Device Host to configure the NFC Controller so that it emulates an NFC Forum tag. This enables the Device Host to store an NDEF message inside the NFC Controller, which can then automatically provide it to a reading device searching for an NDEF message. This is significant because it now enables NFC-enabled mobile devices to keep a specific message active even when the device is switched off. For example, the Device Host can store the content of an airline boarding pass on the mobile device which can be presented to the RF reader at the boarding gate even after the user has already switched off the device to enter the plane. This application also makes sense for theatre ticket use cases where audiences are often asked to switch off their mobile phones during the presentation.
As a nice side effect of this mechanism, the NDEF messages generated in advance by an RF app on the mobile device can be transferred at higher performance than the existing solution where the NDEF message is generated by the RF app on the fly during the RF session.
As you can see, these new features of NCI 2.0 expand and extend the possibilities for using NFC technology in our daily lives. In my next post, I’ll explore further interesting features of NCI 2.0.
Jürgen Böhler is vice-chair of the NFC Forum Technical Committee. He can be reached at [email protected].