Bluetooth: technology for short-range wireless apps

In 1998, five major companies (Ericsson, Nokia, IBM, Toshiba and Intel) formed a group to create a license-free technology for universal wireless connectivity in the handheld market. The result is Bluetooth, a technology named after a 10th-Century king who brought warring Viking tribes under a common rule. The Bluetooth specifications (currently in version 1.1) define a radiofrequency (RF) wireless communication interface and the associated set of communication protocols and usage profiles. The link speed, communication range and transmission power level for Bluetooth were chosen to support low-cost, power-efficient, single-chip implementations of the current technology. In fact, Bluetooth is the first attempt at making a single-chip radio that can operate in the 2.4-GHz ISM (industrial, scientific and medical) RF band. While most early Bluetooth solutions are dual-chip, vendors have recently announced single-chip versions as well. In this overview of the technology, I first describe the lower layers of the Bluetooth protocol stack. I also briefly describe its service discovery protocol and, finally, how the layers of the protocol stack fit together from an application´s point of view