As shown in Figure 1, each FeliCa contactless IC card contains a CPU and operating system (OS) exclusively developed by Sony. This technology supports high-speed data processing. The cards communicate in the 13.56MHz frequency band, which can also supply power. This frequency carries power to the FeliCa card, which contains no battery, while also supporting data communications at 212kbps. Using this technology, a variety of data can be processed between the reader/writer and the FeliCa card in just one-tenth of a second.

In addition to this high-speed read/write capability, FeliCa also provides excellent security and reliability. These characteristics have led to its adoption for use in railway transit pass systems including Suica, ICOCA and TOICA established by Japan Railways (JR) Group. It is also the basis for the PASMO system used by rail and bus commuters in the Tokyo Metropolitan area. FeliCa-based public transportation payment systems have become an indispensable part of Japan's infrastructure, and other operators are planning to adopt the technology as well. Within the JR Group, Kyushu Railway Company and Hokkaido Railway Company will launch their SUGOCA and Kitaca systems in 2009.

Other applications include micro-payment systems, such as Edy operated by bitWallet, Inc., and Seven-Eleven Japan's nanaco system. Ticketing and e-money services can also be accessed using mobile phone "wallets." Interest in the FeliCa technology has rapidly expanded beyond Japan. Octopus Cards in Hong Kong began to use the technology in 1997, and this technology has since been adopted by public transport operators in many parts of the world, including Singapore, China (Shenzhen), India and Thailand. To date Sony has shipped 605 million FeliCa IC chips in Japan and overseas*.

FeliCa technology enables a FeliCa card (IC card) carried by a user to work in tandem with a reader/writer. Data exchanges are carried out using weak electromagnetic waves emitted by the reader/writer.

A FeliCa card is like a tiny computer with its own CPU and OS. However, there is no power supply in the card, which is instead powered by electromagnetic induction. As shown in Figure 2, electricity is generated through the antenna when the card is held over a reader/writer. This activates the CPU inside the card, which then responds to an inquiry from the reader/writer. Data is exchanged by means of changes in resistance inside the FeliCa card, which reflect variations in the strength of the radio waves transmitted by the reader/writer.

The reader/writer initiates data communications by seeking the identity of the FeliCa card. It detects the IC card by means of an identity signal transmitted by the card. To allow the card to be powered through electromagnetic induction, Sony designed the card's wireless system to operate at a frequency of 13.56MHz, which has been approved for use in power transmission. The advantage of electromagnetic induction is that power can be supplied wirelessly. The drawback is that generation capacity varies according to the position and the distance between the coils. However, this characteristic can also be an advantage from a security perspective.

The amount of power generated through electromagnetic induction varies according to the point of contact between the reader/writer and the FeliCa card. For example, contact surface of a reader/writer in an automatic ticket gate in a station is about 15 centimeters long. The FeliCa card receives the highest amount of power when it is near the center. However, if there is a sliding contact between the reader/writer and the FeliCa card, as is likely to occur at a station ticket gate, the CPU could malfunction and corrupt the memory data due to insufficient power if it is activated by a weak starting current emitted around the reader/writer. To prevent this, FeliCa is designed to reset if power is suddenly interrupted, and the CPU is configured to operate at the highest possible efficiency even at the lowest power level.

A key advantage of FeliCa is its significantly faster authentication speed comparred to other IC card systems. This advantage is especially important in Japan, where transportation systems must cope with high passenger volumes. The high-speed processing capacity of the FeliCa system is based on two key technologies. One is an encoding system that can cope with distance-related fluctuations. The other is a unique mutual authentication method.

The FeliCa card sends and receives encoded data produced by the card and the reader/writer. Unlike conventional serial communication, the FeliCa system operates without direct contact. Sony adopted technology to support communication in this special environment. The FeliCa system uses a highly efficient packet communication method. Command data produced by the FeliCa OS and response data to inquiries from the reader/writer are authenticated and recorded between the card and reader/writer. These tasks are carried out using Manchester encoding, which is highly tolerant of distance-related fluctuations.

Manchester Encoding
The card and the reader/writer communicate digitally using 0s and 1s. In the Manchester encoding system, 0s and 1s are transmitted as transitions between high and low signals. A 0 is sent as a waveform that rises from a low level in the middle of the bit period, while for a 1 the waveform starts at a high level and falls. Because there is no direct current component in one -bit duration, it is easy to establish a threshold when the signals are turned back into data. This characteristic allows ensures effective transmission even when there is a big jump in a signal level caused by tapping the FeliCa card on the reader writer.

The FeliCa system employs a unique mutual authentication method between the card and the reader/writer during transaction processing, which involves the processing of multiple tasks in a secure environment. Normally, when authentication is carried out for multiple processes, it is necessary to access and authenticate each function requiring authentication. Because the time required increases with the number of functions, the efficiency of payment and authentication services is reduced.
With the FeliCa system it is not necessary to authenticate individual functions separately and instead generates a composite key is generated. This is a combined key made from multiple access keys. This allows mutual authentication of multiple functions simultaneously. Up to 16 services can be supported at the same time using this abbreviated key. For example, personal authentication, payment, balance, points and other functions can all be carried out instantaneously.

The FeliCa card was the first IC card in the world to be certified under ISO/IEC 15408 EAL4, which is an extremely rigorous international standard for security evaluation. Before FeliCa, it was believed that no contactless IC card would be able to meet this standard including the hardware and operating system. The FeliCa card's security technology is based on mutual authentication between the card and the reader/writer, and on the encryption of transmitted data. Encryption is carried out using an open-standard security algorithm. The encryption key for transmitted data is generated dynamically for each transaction, and random numbers are used during mutual authentication. These measures guard against impersonation and other fraudulent actions.

Sony perfected the FeliCa system by bringing together its accumulated knowledge in various fields of technology, including semiconductor design and fabrication, communications and security. The result is a system that combines robust security with high-speed authentication and the versatility to support applications on a wide range of equipment, including mobile phone "wallets" and PCs. FeliCa technology is already used in Japan and Asia, and there are plans for its adoption in North America and Europe.

By adding Near Field Communication (NFC) capabilities incorporating FeliCa communication technology to consumer electronic equipment, it will be possible to transmit data and make payments using contactless IC cards simply and intuitively. Simple touch controls will provide easy access to an even wider variety of content.