IrDA vs WLAN vs Bluetooth-difference between IrDA,WLAN,Bluetooth
This page on IrDA vs WLAN vs Bluetooth mentions difference between IrDA, WLAN and Bluetooth technologies. The IrDA protocol stack and difference between wireless technologies are also provided.
What is IrDA?
The term IrDA refers to Infrared Data Association. It is a non-profit organization whose goal is to develop specifications for infrared wireless communication. The association has been founded in 1993. The first IrDA 1.0 specifications have been released in the year 1994.
The initial specifications have support for data rate upto 115.2 Kbps. The specification has described IrDA protocol stack. The stack has included SIR, IrLAP and IrLMP layers. Typically IrDA used to support range of about 2 meters. It establishes point to point line of sight communication between IrDA devices. This technology uses light wavelength of 850 to 900 nm for information transmission. IrDA devices communicate using infrared LEDs.
IrDA does not provide link level security. As there is no authorization or authentication specified in IrDA, the information is transmitted as unencrypted. The same is implementation dependent at software level. Though the security is not defined it is considered as relatively secure technology.
IrDA has wide range of applications. IrDA applications include PDAs, Mobile phones. Printers, cameras, laptops etc.
Following are the advantages of the IrDA:
Point to Point data communication
Line of sight application
Low power consumption
Following are the IrDA disadvantages but due to continuous research and more and more new
versions IrDA has become predominant in many applications.
• Line of sight
• One device at a time
Following table specifies difference between IrDA, WLAN and Bluetooth technologies.
|802.11a, 11b, 11g,
|0 to 2 meters
|20 to 100 meters
|10 to 100 meters
|dozens of devices
|2 to 8 devices
|LOS(Line of Sight) requirement
|Max. data rate
IrDA protocol stack
The IrDA protocol stack consists of IrPHY(layer-1), IrLAP(layer-2), IrLMP(layer-3) and other layers on top of IrLMP such as Tiny TP, IrCOMM, OBEX(Object Exchange Protocol), IrSimple etc.
IrPHY is the IrDA physical layer. It specifies optical link features, modulation-code rates, CRC and framing details.
These difference modulation and coding techniques are used in IrDA to support different data rates.
They are outlined as follows:
• SIR(Serial Infrared)-supports data ratas from 9.6 to 115.2 Kbps
• MIR-supports data rate from 0.576 to 1.152 Mbps
• FIR(Fast Infrared)-Supports upto 4Mbps
• VFIR(Very Fast Infrared)-supports upto 16Mbps
• UFIR-Supports upto 96Mbps
• GigaIR-Supports from 512Mbps to 1Gbps data rates
Recently IrDA has created 5 and 10 Gigabit optical wireless communications workgroup for research in this area. It is known as 5/10 GigaIR. This is new IrPHY (physical layer) to support higher data rates with IrDA technology.