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Information about Infrared Data Association

This article is about an Infrared communications protocol. For a fictional species in the Dragonlance series, see Irda (Dragonlance).


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IrDA via USB
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IrDA in mobile phone Siemens CXT70


The Infrared Data Association (IrDA) defines physical specifications communications protocol standards for the short-range exchange of data over infrared light, for uses such as personal area networks (PANs). For the devices to communicate via IrDA they must have a direct line of sight.

Specifications

IrPHY

The mandatory IrPHY (Infrared Physical Layer Specification) is the lowest layer of the IrDA specifications. The most important specifications are:
  • Range (Standard: 1 m, low-power to low power: 0.2 m, Standard to low power: 0.3 m)
  • Angle (minimum cone +-15°)
  • Speed (2.4 kbit/s to 16 Mbit/s)
  • Modulation (Base band, no carrier)
  • Infrared window
IrDA transceivers communicate with infrared pulses in a cone that extends minimum 15 degrees half angle off center. The IrDA physical specifications require that a minimum irradiance be maintained so that a signal is visible up to a meter away. Similarly, the specifications require that a maximum irradiance not be exceeded so that a receiver is not overwhelmed with brightness when a device comes close. In practice, there are some devices on the market that do not reach one meter, while other devices may reach up to several meters. There are also devices that do not tolerate extreme closeness. The typical sweet spot for IrDA communications is from 5 cm to 60 cm away from a transceiver, in the center of the cone. IrDA data communications operate in half-duplex mode because while transmitting, a device’s receiver is blinded by the light of its own transmitter, and thus, full-duplex communication is not feasible. The two devices that communicate simulate full duplex communication by quickly turning the link around. The primary device controls the timing of the link, but both sides are bound to certain hard constraints and are encouraged to turn the link around as fast as possible. Transmission rates fall into three broad categories: SIR, MIR, and FIR. Serial Infrared (SIR) speeds cover those transmission speeds normally supported by an RS-232 port (9600 bit/s, 19.2 kbit/s, 38.4 kbit/s, 57.6 kbit/s, 115.2 kbit/s). Since the lowest common denominator for all devices is 9600 bit/s, all discovery and negotiation is performed at this baud rate. MIR (Medium Infrared) is not an official term, but is sometimes used to refer to speeds of 0.576 Mbit/s and 1.152 Mbit/s. Fast Infrared (FIR) is deemed an obsolete term by the IrDA physical specification, but is nonetheless in common usage to denote transmission at 4 Mbit/s. “FIR” is sometimes used to refer to all speeds above SIR. However, different encoding approaches are used by MIR and FIR, and different approaches frame MIR and FIR packets. For that reason, these unofficial terms have sprung up to differentiate these two approaches. The future holds faster transmission speeds (currently referred to as Very Fast Infrared, or VFIR) which will support speeds up to 16 Mbit/s. There are (VFIR) infrared transceivers available such as the TFDU8108 operating from 9.6 kbit/s to 16 Mbit/s. The UFIR (Ultra Fast Infrared) protocol is also in development. It will support speeds up to 100 Mbit/s.

IrLAP

The mandatory IrLAP (Infrared Link Access Protocol) is the second layer of the IrDA specifications. It lies on top of the IrPHY layer and below the IrLMP layer. It represents the Data Link Layer of the OSI model. The most important specifications are:
  • Access control
  • Discovery of potential communication partners
  • Establishing of a reliable bidirectional connection
  • Negotiation of the Primary/Secondary device roles
On the IrLAP layer the communicating devices are divided into a Primary Device and one or more Secondary Devices. The Primary Device controls the Secondary Devices. Only if the Primary Device requests a Secondary Device to send is it allowed to do so.

IrLMP

The mandatory IrLMP (Infrared Link Management Protocol) is the third layer of the IrDA specifications. It can be broken down into two parts. First, the LM-MUX (Link Management Multiplexer) which lies on top of the IrLAP layer. Its most important achievements are:
  • Provides multiple logical channels
  • Allows change of Primary/Secondary devices
Second, the LM-IAS (Link Management Information Access Service), which provides a list, where service providers can register their services so other devices can access these services via querying the LM-IAS.

Tiny TP

The optional Tiny TP (Tiny Transport Protocol) lies on top of the IrLMP layer. It provides:
  • Transportation of large messages by SAR (Segmentation and Reassembly)
  • Flow control by giving credits to every logical channel

IrCOMM

The optional IrCOMM (Infrared Communications Protocol) lets the infrared device act like either a serial or parallel port. It lies on top of the IrLMP layer.

IrOBEX

The optional IrOBEX (Infrared Object Exchange) provides the exchange of arbitrary data objects (e.g. vCard, vCalendar or even applications) between infrared devices. It lies on top of the Tiny TP protocol, so Tiny TP is mandatory for IrOBEX to work.

IrLAN

The optional IrLAN (Infrared Local Area Network) provides the possibility to connect an infrared device to a local area network. There are three possible methods: As IrLAN lies on top of the Tiny TP protocol, the Tiny TP protocol must be implemented for IrLAN to work.

IrSimple

IrSimple achieves at least 4 to 10 times faster data transmission speeds by improving the efficiency of the infrared IrDA protocol. IrSimple protocol maintains backward compatibility with the existing IrDA protocols.

IrSimpleShot

One of the primary targets of IrSimpleShot (IrSS) is to allow the millions of IrDA-enabled camera phones to wirelessly transfer pictures to printers and printer kiosks.

This is a test

Popularity

IrDA was popular on laptops and some desktops during the late 90s through the early 2000s. However, it has been displaced by other wireless technologies such as WiFi and Bluetooth, favored because they don't need a direct line of sight, and can therefore support hardware such as mice and keyboards. It is still used in some environments where interference makes radio-based wireless technologies unusable.

See also

External links

Literature

Charles D. Knutson with Jeffrey M. Brown, IrDA Principles and Protocols, 2004, ISBN 0-9753892-0-3
Dragonlance is a large series of fantasy novels, with over 190 novels printed, and is accompanied by a supplemental campaign setting in the Dungeons & Dragons style.
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The Irda are a fictional species in the fantasy world of Dragonlance. They are the first born of the Evil gods, and also the ancient predecessors of the contemporary Ogres.

Physical description

Irda are tall, humanoid creatures with slender frames and blue skin.
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computing protocols, see Protocol (computing). For protocols on two-way voice communications, see Voice procedure. For other meanings of the word protocol, see Protocol.
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standardization or standardisation can have several meanings depending on its context. Common use of the word standard implies that it is a universally agreed-upon set of guidelines for interoperability.
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For other uses, see Data (disambiguation).


Debt, AIDS, Trade in Africa (or DATA) is a multinational non-government organization founded in January 2002 in London by U2's Bono along with Bobby Shriver and activists from the Jubilee 2000 Drop
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Infrared (IR) radiation is electromagnetic radiation of a wavelength longer than that of visible light, but shorter than that of radio waves. The name means "below red" (from the Latin infra, "below"), red being the color of visible light with the longest wavelength.
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A personal area network (PAN) is a computer network used for communication among computer devices (including telephones and personal digital assistants) close to one person. The devices may or may not belong to the person in question.
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Free Space Optics (FSO) is a telecommunication technology that uses light propagating in free space to transmit data between two points. The technology is useful where the physical connection of the transmit and receive locations is difficult, for example in cities where the laying
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In telecommunications and computer networking, a network interface is one of:
  1. The point of interconnection between a user terminal and a private or public network.
  2. The network card on a computer (in casual usage).

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Personal digital assistants (PDAs) are handheld computers, but have become much more versatile over the years. PDAs are also known as pocket computers or palmtop computers.
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mobile phone or cell phone is a long-range, portable electronic device used for mobile communication. In addition to the standard voice function of a telephone, current mobile phones can support many additional services such as SMS for text messaging, email, packet switching
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laptop computer, or simply laptop (also notebook computer or notebook), is a small mobile computer, which usually weighs 2-18 pounds (1-6 kilograms), depending on size, materials, and other factors.

A laptop computer is much smaller than a desktop.
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Bluetooth is an industrial specification for wireless personal area networks (PANs). Bluetooth provides a way to connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras, and video game consoles over a secure, globally
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specification is an explicit set of requirements to be satisfied by a material, product, or service. (ASTM definition)

Use of a Specification

In engineering, manufacturing, and business, it is vital for suppliers, purchasers, and users of materials, products, or
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IrFM is a wireless payment standard developed by the Infrared Data Association.

External links

  • IrFM Webpage

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IrFM is a wireless payment standard developed by the Infrared Data Association.

External links

  • IrFM Webpage

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Irradiance, radiant emittance, and radiant exitance are radiometry terms for the power of electromagnetic radiation at a surface, per unit area. "Irradiance" is used when the electromagnetic radiation is incident on the surface.
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A duplex communication system is a system composed of two connected parties or devices which can communicate with one another in both directions. (The term duplex is not used when describing communication between more than two parties or devices.
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A duplex communication system is a system composed of two connected parties or devices which can communicate with one another in both directions. (The term duplex is not used when describing communication between more than two parties or devices.
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In telecommunications, RS-232 (Recommended Standard 232) is a standard for serial binary data signals connecting between a DTE (Data terminal equipment) and a DCE (Data Circuit-terminating Equipment). It is commonly used in computer serial ports.
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data link layer is layer two of the seven-layer OSI model as well as of the five-layer TCP/IP reference model. It responds to service requests from the network layer and issues service requests to the physical layer.
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Open Systems Interconnection Basic Reference Model (OSI Reference Model or OSI Model for short) is a layered, abstract description for communications and computer network protocol design, developed as part of the Open Systems Interconnection (OSI) initiative.
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serial port is a serial communication physical interface through which information transfers in or out one bit at a time (contrast parallel port). Throughout most of the history of personal computers, data transfer through serial ports connected the computer to devices such as
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parallel port is a type of socket found on personal computers for interfacing with various peripherals. It is also known as a printer port or Centronics port. The IEEE 1284 standard defines the bi-directional version of the port.
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vCard

File extension: .vcf, .vcard
MIME type: text/x-vcard
text/directory;profile=vCard
text/directory
Type code: vCrd
Uniform Type Identifier: public.
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vCalendar is an older standard exchange format for calendar data promulgated by the Internet Mail Consortium (IMC). iCalendar is a newer standard (RFC 2445) for calendar data, heavily based on vCalendar.
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wireless access point (WAP or AP) is a device that connects wireless communication devices together to form a wireless network. The WAP usually connects to a wired network, and can relay data between wireless devices and wired devices.
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peer-to-peer (or "P2P") computer network exploits diverse connectivity between participants in a network and the cumulative bandwidth of network participants rather than conventional centralized resources where a relatively low number of servers provide the core value to a
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This article is about a radio station in New Jersey. For the brand name used for wireless local area networks, see Wi-Fi.


WIFI, 1460 AM, is a radio station broadcasting out of Florence, New Jersey. It has a Christian Contemporary format.
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Bluetooth is an industrial specification for wireless personal area networks (PANs). Bluetooth provides a way to connect and exchange information between devices such as mobile phones, laptops, PCs, printers, digital cameras, and video game consoles over a secure, globally
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