Near-field communications operate in the 13.56 MHz band over a typical distance of a few centimeters. Many believe NFC will be used in cellphones so that they can make automatic payments for a wide variety of services, but deployments of the wireless technology in handsets have been slow for a variety of reasons said backers at an NFC event in April.

The NFC Digital Protocol defines the digital interface, bit level coding, bit rates, frame formats, protocols, and command sets covering initiator, target reader/writer and card emulator functions. It enables NFC devices to talk to each other and to connect to other existing contactless communications devices--including those based on Sony's FeliCa technology--by providing support for a subset of existing ISO/IEC 18092 and ISO/IEC 14443 standards.

The NFC Logical Link Control Protocol defines peer-to-peer communication between devices, supporting bi-directional links. It defines two service types and three service classes and is based on the IEEE 802.2 standard.

"As more NFC devices and applications come to market, it is essential that we ensure their smooth interoperability with earlier NFC implementations," said Koichi Tagawa, chairman of the NFC Forum in a prepared statement. "These two specifications are significant because they establish clear and well-defined parameters for the implementation behavior of NFC devices and applications, thereby providing this needed assurance."

Both the specs are candidates for final release pending feedback from NFC Forum members and other standards organizations. Once the feedback has been evaluated and integrated, both specifications will be officially approved and released by the NFC Forum.

The NFC Forum's members include Hewlett-Packard, Inside Contactless, MasterCard Worldwide, Microsoft, NEC, Nokia, NTT DoCoMo, Inc., NXP, Panasonic, Renesas, Samsung, Sony, STMicroelectronics and Visa. It was formed in 2004.