As Bluetooth and Wi-Fi were designed to serve differing usage scenarios, it is no surprise that the performance of the two systems differs as well. Bluetooth trades off speed for lower power consumption, whereas Wi-Fi attempts to match the performance of wired LANs. Bluetooth supports two types of links – packet and connection-oriented (known as SCO). Packet connection is used for data transmission and can operate symmetrically or asymmetrically. The maximum symmetric data transfer rate is 433.9 kbps in each direction; the maximum asymmetric data rate is 723.2 kbps upstream (57.6 kbps downstream). Dedicated connection-oriented links are used for audio applications. Bluetooth can support three 64 kbps voice channels simultaneously. These data rates are sufficient to accommodate the usage scenarios described in earlier sections. Wi-Fi supports four different data rates: 11 Mbps, 5.5 Mbps, 2 Mbps and 1 Mbps. A ratescaling algorithm is used to reduce the data rate when errors are detected in transmission. The result is that the data rate is reduced as a user moves farther away from an AP.
When a user wishes to connect to a LAN, Wi-Fi offers a simpler procedure, as it has been optimized for this function. Assuming a WLAN card is already in place, the user need merely turn on her computing device and enter the necessary authenticating user name and password. The user is then on the network. For Bluetooth, the process is lengthier, possibly requiring each of the following steps: 1) device discovery; 2) device connection; 3) the establishment of a LAN access connection; 4) the establishment of a PPP connection; 5) PIN entry; 6) network user name and password entry. Though most of these steps can be accomplished with a single click of the mouse or tap of the stylus, the entire process could take as long as 30 seconds. The fact that Bluetooth enables communication between disparate device types using many different types of applications means, inevitably, that some procedures will take longer with Bluetooth than with applicationspecific technologies such as Wi-Fi. In order to streamline this process, Pico has developed a proprietary application -- PicoConnect™ -- that allows onetouch network access.
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