IrDA

IrDA is a wireless standard designed for data transmission using infrared (IR). Infrared ports for this purpose have been implemented in portable electronic devices such as mobile telephones, laptops, cameras, printers, and medical devices. The main characteristics of this kind of wireless optical communication are short-range, physically secure and bidirectional data transfer, at serial cable speeds, with a line-of-sight using point-and-shoot principles. IrDA has been made dormant by newer improved technologies like Bluetooth.

The protocols and specifications of the standard were developed by the Infrared Data Association (abbreviated IrDA, giving the name to the standard itself), an industry-driven interest group that was founded in 1993 by around 50 companies. Before IrDA, a number of proprietary standards existed for data exchange using infrared beams but the new association aimed to create an industry standard. The IrDA specifications were published in June 1994. In November 1995, Microsoft announced that it will support in Windows 95. The majority of PCs shipped in 1996 included an infrared port to utilize IrDA connectivity and the same year the first digital camera (Sony's DSC-F1) was released for infrared connectivity with a PC or printer.

The Infrared Data Association released the IrDA 1.0 specification in June 1994. In October 1995, IrDA 1.1 was specified that included improved theoretical data transmission speeds. IrDA 1.2 was approved in October 1997 designed to be low power, reducing costs. Version 1.3 was released in 1998 and the IrDA 1.4 implementation was released in 2001.

Development of the standard slowed because of the competing radio wave based Bluetooth standard. Between 2000 and 2002 several members of the Infrared Data Association, including Apple, IBM and Nokia, left the organisation and had joined the Bluetooth Special Interest Group. However the organisation continued to build on the technology and published the Ultra Fast (UFIR) IrDA standard in 2006 with a net data rate of 96 Mbps. In 2009, the Infrared Data Association (IrDA) published Giga-IR which aims for data speeds of 512 Mbps or 1 Gbps.

The association also adopted new standard called IrSimple in August 2005. The development of IrSimple is credited to NTT Docomo, Sharp, ITX E-globaledge and Waseda University. IrSimple provides significantly faster data transmission but maintains backward compatibility with the existing IrDA-enabled protocols. The IrSimple protocols provide sub-1-second transfers of pictures between cell phones, printers, and display devices. For example, some Pentax DSLRs (K-x, K-r) incorporated IrSimple for image transfer and gaming.

IrDA was popular on PDAs, laptops and some desktops from the late 1990s through the early 2000s. It was a cable-free way for applications such as transferring files, printing, or tethering.

However, IrDA has been displaced by other wireless technologies such as Bluetooth, and Wi-Fi, favored because they don't need a direct line of sight and can therefore support hardware like mice and keyboards. However, for some time IrDA hardware was still less expensive and didn't share the same security problems encountered with the likes of Bluetooth. It is still used in some environments where interference makes radio-based wireless technologies unusable.

The mandatory IrPHY (Serial Infrared Physical Layer Specification) is the physical layer of the IrDA specifications. It comprises optical link definitions, modulation, coding, cyclic redundancy check (CRC) and the framer. Different data rates use different modulation/coding schemes: