Networking Technology - Redtacton

A presentation on

by

Human Area

Networking Technology:

RedTacton

ABSTRACT:

Ubiquitous services that are genuinely user-friendly to everyone will require technologies that enable communication between people and objects in close proximity. So far we have seen LAN, MAN, WAN, INTERNET and many more. Focusing on the naturalness, inevitability, and sense of security conveyed by touching in everyday life, this paper describes human area networking (HAN) technology that enables communication by touching, which we call RedTacton

. NTT lab from Japan is currently testing & developing this revolutionary technology. In this, the human body acts as a transmission medium supporting IEEE 802.3 half-duplex communication at 10 Mbit/s. The key component of the transceiver is an electric-field sensor implemented with an electro optic crystal and laser light. RedTacton enables the first practical Human Area Network between body-centered

Electronic devices and PCs or other network devices embedded in the environment via a new generation of user interface based on totally natural human actions such as touching, holding, sitting, walking, or stepping on a particular spot.

In this paper we will discuss about Redtacton, its working, applications and comparison with other technologies for data transmission.

INTRODUCTION:

Today people can communicate anytime, anywhere, and with anyone over a cellular phone network. Moreover, the Internet lets people download immense quantities of data from remotely located servers to their home computers. Essentially, these two technologies enable communications between terminals located at a distance from each other. Meanwhile, all kinds of electronic devices including personal digital assistants (PDAs), pocket video games, and digital cameras are becoming smaller, so people can carry around or even wear various personal information and communication appliances during their everyday activities. However, user-friendly ubiquitous services involve more than just networking between remotely located terminals. Communication between electronic devices on the human body (wearable computers) and ones embedded in our everyday environments such as illustrated in Fig. 1 is also critical, so this has driven extensive research and development on human area networks.

Wired connections between electronic devices in human area networks are cumbersome and can easily become entangled. Short-range wireless communication systems such as Bluetooth and wireless local area networks (IEEE 802.11b, etc.) have some problems. Throughput is reduced by packet collisions in crowded spaces such as meeting rooms and auditoriums filled with people and communication is not secure because signals can be intercepted. The principle drawback of infrared communications (IrDA) is the tight directionality of beams between terminals needed for the system to be effective. The ultimate human area network solution to all these constraints of conventional technologies is "intrabody" communication, in which the human body serves as the transmission medium. In ubiquitous services (which imply communication

between electronic devices embedded in the environment in close proximity to people), if we could use the human body itself as a transmission medium, then this would be an ideal way of the human body to transmit information, was first proposed by IBM. The communication mechanism has subsequently been evaluated and reported by several research groups around the world. However, all those reported technologies had two limitations:

Fig 1 human area networking technology

1) The operating range through the body was limited to a few tens of centimeters and

2) The top communication speed was only 40 kbit/s.

These limitations arise from the use of an electrical sensor for the receiver. An electrical sensor requires two lines (a signal line and a ground line), whereas in intra-body communication there is essentially only one signal line, i.e., the body itself, which leads to an unbalanced transmission line, so the signal is not transmitted correctly.

HUMAN AREA NETWORKING:

NTT has had excellent success with an electro-optic sensor combining an electro optic crystal with laser light and recently reported an application of this sensor for measuring high-frequency electronic devices. The electro-optic sensor has three key

Features:

1. It can measure electric fields from a device under test (DUT) without contacting it, which minimizes measurement disturbance,

2. Ultra wide-band measurement is possible, and

3. It supports one-point contact measurement that is independent of the ground, which is the most significant feature in the present context.

NTT utilized this third feature to fabricate an intrabody communication receiver for its human area networking technology, which is called RedTacton*

Instead of relying on electromagnetic waves or light waves to carry data, RedTacton uses weak electric fields on the surface of the body as a transmission medium. The chips which will be embedded in various devices contain transmitter and receiver built to send and accept data in digital format .A RedTacton transmitter couples with extremely weak electric fields on the surface of the body. The weak electric fields pass through the body to a RedTacton receiver, where the weak electric fields affect the optical properties of an electro-optic crystal. The extent to which the optical properties are changed is detected by laser light which is then converted to an electrical signal by a detector circuit.

The operating principle of RedTacton is illustrated in Fig. 2. The electric field induced toward the body by the transmitter's signal electrode is represented by Ea. The system requires a ground close to the transmitter signal electrode, so electric field Eb induced from the body can follow a return path to the transmitter ground. Moreover, since people are usually standing on a floor or the ground, electric field Ec escapes from the body to ground, mainly from the feet. The electric field Es that reaches the receiver is

Es

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