08-06-2010, 09:26 PM
The objective of this seminar is to give an outline for a Push-to-Talk (PTT) system that utilizes a Bluetooth scatternet and the Personal Area Networking (PAN) profile for data communications . The system is thus fully independent of cellular networks. A reasonable range of several hundred meters can be obtained with multihop communications between Bluetooth class 1 devices, whose range is up to 100 m. The outline of Push-to-Talk over Bluetooth (PoB) comprises methods for group formation, network formation, communication, and floor control. The network formation method, which can be utilized in other applications as well, is based on creating a scatternet among a predefined set of devices and on avoiding loops. This approach enables usage of a simple broadcasting based communication method, in which the devices bridging the piconets into a scatternet act as repeaters. the previous technology Push-to-Talk over Cellular (PoC) is enabling a walkie- talkie-like service over GPRS. an open standard for PoC is being speciï¬Âed by the Open Mobile Alliance (OMA). And a subsidiary objective of this paper is also to provide a description of OMA PoC and the protocols it relies upon. The description serves both as a basis for pursuing the primary objective and as a tutorial, which is suitable for students or professionals desiring to acquaint themselves with OMA PoC. The proposed outline for Push-to-Talk over Bluetooth (PoB) comprises e.g. methods for group formation, network formation, communication, and floor control. The network formation method, which can be utilized in other ap- plications as well, is based on creating a scatternet among a predeï¬Âned set of devices and on avoiding loops. This approach enables usage of a simple broadcasting based communication method, in which the devices bridging the piconets into a scatternet act as repeaters. A method for combining PoB and PoC is also outlined. It is intended for en- abling PTT-communication with both local and distant group members over Bluetooth and GPRS respectively.