ilips and Sony, and is based on the ECMA 340 standard. The technology is being promoted by the NFC Forum, whose sponsor members also include MasterCard, Motorola, Nokia and Visa International. Chapter Ten The ECMA 340 standard was adopted by the ECMA General Assembly in December 2004, and defines NFC communication modes using inductive coupled devices operating at a centre frequency of 13.56 MHz. The definition is also known as the near field communication interface and protocol (NFCIP-1). Similar to the more familiar IEEE standards, ECMA 340 specifies the modulation and data coding schemes, data rates and frame format for NFC device interfaces. A simple link layer protocol addresses link initialisation and collision avoidance, and a transport protocol, covers protocol activation, data exchange and deactivation. NFC PHY Layer ECMA 340 specifies a magnetic induction interface operating at 13.56 MHz and with data rates of 106, 212 and 424 kbps, which is compatible with Philips' MIFARE® and Sony's FeliCaTM contactless smart card interfaces. Rather than measuring transmitter power and receiver detection levels in dBm as is the case for far-field RF communication, the strength (H) of the magnetic field used in NFC is measured in amps/metre (A/m). ECMA 340 specifies the field values as shown in Table 10-17. The ECMA 340 standard defines two communication modes - active and passive. In the active mode, communication is started by an RF field generated by the initiating device (the Initiator) and the target device (the Target) also generates a modulated RF field to respond to the Initiator's command. Modulation and bit coding methods used in active mode are shown in Table 10-18. In the passive mode (Table 10-19), the Initiator starts the communication using an RF field but the Target responds by load modulation rather than by generating an RF field in response. Load modulation, described in the Table 10-17: ECMA 340 NFC Magnetic Field Strength Specification Field level Field strength Description Hthreshold 0.1875 A/m Min