Trade Offs

Although both technologies can be found in similar devices, their applications are inherently different. IR is suitable for applications where data transmission takes place at high speeds over a closely proximate line of sight paths. A good example would be data exchange between PDAs, notebook computers and printers.

On the other hand, omnidirectional Bluetooth devices may find it difficult to find each other even when they are in close proximity. Since Bluetooth transmissions are omnidirectional, carrying up to 100 m, they also lack the inherent line-of-sight security feature of IR. Files being exchanged will probably need to be encrypted and, possibly, password-protected.

Another application where IR is more suitable than Bluetooth is in the area of medical and health care. IR technology, unaffected by RFI, ensures that data transmission can be executed safely and effectively. Bluetooth will have potential problems with RFI and EMI, as well as other medical devices, causing disruptions and data errors.

Bluetooth is more appropriate for applications where line of sight is not desirable. For instance, users could synchronise their telephones without having to remain stationary. Bluetooth technology can also penetrate solid objects, allowing users to place telephones in their pockets while synchronising.

The Bluetooth-IrDA SIG was established to identify, specify and promote ways that both technologies can work together to provide additional benefits to the user. According to the organisation's convener, Glade Diviney, IrDA can assist Bluetooth in two main areas. IrDA can assist Bluetooth to connect rapidly with a targeted device. Bluetooth, which operates omnidirectionally, may have difficulty trying to detect its intended target master or slave unit. IrDA and Bluetooth can also work together to provide connectivity over varying distances. While Bluetooth can reach its target of up to 100 m, its speed is slower. A device could use IrDA for rapid data exchange when it is placed close to its recipient. Subsequently, the device could change to Bluetooth when its targeted device is more than 10 m away.