The Single Wire Protocol (SWP) is a method of Near Field Communication (NFC) which provides an interface between the SIM Card and a cell phone’s contactless front-end chip (CLF).
SWP enables contactless communication between devices. First, the CLF facilitates communication between the contactless devices and the SIM Card, so transactions are device-specific.
The host controller interface (HCI) is a high level protocol that enables reliable data exchanges using the SWP physical layer.
The HCI enables the SWP to create a host network and support contactless applications, using the SIM Card.
Connectivity between the Sim Card and CLF using the single-wire protocol with a host controller interface must be verified, as a large volume of contactless transactions depends on this technology’s functionality. Interoperability between platforms and design validation is essential to ensure functionality outside of a laboratory context. A good testing service of a SWP link includes conformance to both electrical and protocol tests.
What SWP-HCI does
The SWP facilitates interoperability between the SWP-HCI handset and the SIM Card. The single-wire protocol, when used with the host controller interface, allows a duplex protocol: it is possible to transmit and receive diverse contactless communications simultaneously when enabled.
A Single Wire Protocols link allows a CLF to exchange with a SIM card when communicating with an external contactless device. Connecting by a physical single wire, the CLF transmits data to the SIM card by performing voltage modulation, while the card will answer by modulating current on the same physical link. Devices that use the single-wire protocol with host controller interface have been in production since 2008, when the final technical specification was released (ETSI TS 102 622 V.12.1.0 and ETSI TS 102 613 V.11.0.0).
How to test SWP-HCI conformance
Mobile platforms that use the single-wire protocol with host controller interface technology must be tested in laboratories using . Testing is essential to validate design success and interoperability between the CLF and Sim Card via the single wire. Data transmitted down the single wire should be perceptible in binary.
Smart cards necessarily must meet industry standards for contact signaling, and SWP-HCI testing guarantees all conform to this standard. Testing emulates wireless, Bluetooth, and other NFC communication in diverse environments to ensure operability beyond a laboratory context. Testing the SWP-HCI interface ensures that each component (including the CPU, Sim Card, and CLF) communicate accurately via the single-wire, enabling duplex transactions in a variety of circumstances. An appropriate test must validate and certificate this connectivity.
The testing of the HCI/SWP interface must be done with tools that implement the ETSI TS 102.694 and ETSI TS102.695 norms, either it is a smartphone or a sim card. There are automated tools available on the market to proceed.
About the technology
The final technical specification which perfected connectivity between the SIM card and contactless devices via a single-wire protocol with a host controller interface was released in 2008. Devices were already in production at the time of the technical report’s release, but cell phones with this technology weren’t available on the market until 2011.
Interfaces between the SIM card and the CLF enable near-field communications and the SWP-HCI facilitates this. Testing is necessary to ensure conformance to industry standards for contact signaling. Testing also provides engineers with accurate technical information to improve the technology’s application for transit fare collection, access control, and payment in the future.