Infrared Data Communication is a simple example of short range wireless network. The most important characteristics of IrDA Communication consist of range, angle and modulation. The Standard range of two devices in an infrared line of sight network is 1 m with low-power to low power is 0.2 m and Standard to low power: 0.3 m.
The minimum angle for cone should be Angle +-15°. Infrared Speeds vary from Speed 2.4 kbit/s to 16 Mbit/s. Two modulation levels are available in this communication consisting of Base band and no carrier.
Infrared Communication is very agile and is interrupted by various factors including angle, distance, noise and heat. Light waves also form an interruption pattern in Infrared Communication. Infrared Communication works on a few layers which constitute the complete Infrared Communication Protocol for Data Transfer and Communication between IrDA devices.
These Layers include IrPHY (Infrared Physical Layer), IrLAP (Infrared Link Access Protocol), IrLMP (Infrared Link Management Protocol), Tiny TP (Tiny Transport Protocol), IrCOMM (Infrared Communications Protocol), IrOBEX (Infrared Object Exchange), IrLAN (Infrared Local Area Network), IrS (IrSimple) and IrSS (IrSimpleShot). All these layers combine to form the Infrared Communication possible in this network.
The biggest drawback in infrared communication is its range and angle problems which makes its impossible for modern day mobility needs to be fulfilled by this protocol.
The operating frequencies are also very low which makes it more prone to certain distortion sources.
IrPHY is equivalent to Physical layer of OSI model and handles the Medium transformation rates and connectivity characteristics of IrDA Network which IrLAP is like the Data Link Layer in OSI model.
The main responsibilities of IrLAP include Access control, Discovery of potential communication partners, Establishing of a reliable bidirectional connection and Negotiation of the Primary/Secondary device roles. The Third Layer IrLMP can be further subdivided into First is LM-MUX (Link Management Multiplexer) which lies on top of the IrLAP layer.
It provides multiple logical channels and allows change of Primary/Secondary devices. Te second is 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 provide Transmission and Flow control features in IrDA Network. IrCOMM acts like a serial or parallel poert on top of transmission layer for application integration. IrSimple provides two functionalities including enhancing transfer rates 4 – 10 times by improving IrDA Protocol It also provides backward compatibility with other IrDA Protocols.
IrSS is used by Infrared Camera to transfer pictures to Printers. It has the functionality of TV remote control with transfer rates of up to 16 Mbps.