Bluetooth Multicast Technology Research Based On The Central Server Model

As a short-range wireless communication technology, Bluetooth has been widely applied in all aspects of life. In particular, the Bluetooth is popularly used in the field of intelligence, along with the rapid development of smart phones and other intelligent devices. In the Bluetooth standard protocol, a master device can communicate with a maximum of seven slaves at the same time. And they form the network called the piconet. Multiple piconets can constitute a larger network called the scatternet. In the piconet, it can only support a small number of multicast communication between devices. Although scatternet can support more devices, but there is the problem of same frequency interference which will reduce the overall quality of communication networks. Therefore, the realization of effective Bluetooth multicast is an urgent problem to be solved.Firstly, this paper expounds the Bluetooth protocol, and analyzes the Bluetooth protocol stack. Then the paper emphatically introduces Bluetooth baseband specification, including the channel and the time slot, the physical link, the baseband packet and the mechanism of the data sending, receiving and error control. For the restricted problem of Bluetooth protocol supports more devices are discussed, and finally the paper explained two kinds of scheduling algorithm of Bluetooth piconet: static scheduling algorithm and dynamic scheduling algorithm.Through the detailed study of the Bluetooth protocol and the multicast communication’s shortcomings, this paper presents a central server model. The model by improving the Bluetooth baseband protocol of the Central Server, breaking the traditional Bluetooth protocol can only support seven devices, implements a central server device can support more devices to communicate at the same time. It not only solves the problem of communication between a plurality of devices, but also avoid the problem of same frequency interference between piconets. Then, this paper analyzes the performance of the communication model from the communication cycle and the device wait scheduling time and so on.The paper also analyzes Round Robin scheduling algorithm’s shortcomings, and puts forward the Equality of Active Scheduling Algorithm(EASA) which is based on active degree. EASA will be based on the network from the degree of the equipment to change active scheduling order, ensuring a high degree of active devices is preferentially scheduling, shorten the waiting time of scheduling. So the EASA scheduling algorithm can not only improve the performance of network central server communication model, but also guarantee fairness of communication between the devices.