Fast Infrared (FIR) is an IrDA method in which data is transmitted at 4 Mbit/s via infrared light. FIR transmission was standardized by the Infrared Data Association (IrDA) and has evolved from the first specifications for point-to-point transmission with infrared light.
The first specification from the early 1990s specified IR transmissions at a data rate of 115 kbit/s. This data rate was later increased to 4 Mbit/s for Fast Infrared (FIR). Fast Infrared has a Cyclic Redundancy Checksum(CRC) that operates at 32 bits. The layer above Very Fast Infrared( VFIR) works with the IrDA Link Access Protocol( IrLAP), which establishes the infrared link, the IrDA Link Management Protocol( IrLMP), which supports network services such as printing, and the IrDA Transport Protocol( IrTP), which can manage multiple data streams simultaneously.
Fast Infrared evolved into Very Fast Infrared (VFIR) in 1999, which makes it to 16 Mbps and uses the same protocol stack. Later, Ultra Fast Infrared( UFIR) was introduced with a data rate of 96 Mbit/s, and Giga Infrared( GIR) with data rates of 512 Mbit/s and 1 Gbit/s.