Research On The MAC Scheduling Of The Bluetooth Piconet

Bluetooth Piconet is made up of one Master and up to seven Slaves. The commucation only happens between Master and Slave, and it is not allowed between Slave and Slave.The data which is transmited is named packet.The devices in the Piconet share a single channel.Therefor,it is nessary to control the Master polling which is responsible for choosing the device to use the single channel. The Bluetooth Specification makes use of a Time Divison Duplex (TDD),and the channel is divided each into slots.A slave is allowed to transmit a Bansband packet only if in the previous time slot the Master sends data to the Slave. At the present time, the Bluetooth Specification recommends a simple round robin scheme,but it does not fit the Bluetooth transmiting system.It wastes the bandwidth and is not able to support quality of the service(QoS) guarantees.A number of such schemes have been propsed,but virtually none of them is consider as the best. This paper analyse the propsed scheduling, classfy them, and make conclusion about what are the main factors that affect the transmation performance. This paper propsed a new scheduling named Adaptive Cycle_Elimited Scheduling (AQAS) which partly supports the QoS.In order to validate the performance of the AQAS,This paper build a test platform using NS2 and UCBT,configure the experimentational environment and to do the simulation experiment using the AQAS and the E_limited scheduling which is thought as a better scheduling in the Piconet. The results indicate that the Adpative Cycle_Limited Scheduling is better than the E_limited scheduling, and partly surports the QoS requirements.