If you examine the benefits of each technology, you can see that Bluetooth and IrDA are both critical to the marketplace. Each technology has advantages and drawbacks and neither can meet all users' needs. Bluetooth's ability to penetrate solid objects and its capability for maximum mobility within the piconet allows for data exchange applications that are very difficult or impossible with IrDA. For example, with Bluetooth a person could synchronize their phone with a PC without taking the phone out of their pocket or purse (this is not possible with IrDA). The omni-directional capability of Bluetooth allows synchronization to start when the phone is brought into range of the PC.The Bluetooth standard defines the layers 1 and 2 of the OSI model. The application framework of Bluetooth is aimed to achieve interoperability with IrDA and WAP. In addition, a host of other applications will be able to use the Bluetooth technology and protocols.