Research And Hardware Design Of MAC Sublayer Based On ZigBee Technology

ZigBee technology is a low data rate, low power consumption, low cost, wireless networking protocol targeted towards automation and remote control applications. IEEE802.15.4 committee works on the standard to address the need for low-rate low-power wireless network. Then the ZigBee Alliance and the IEEE join forces and ZigBee is the commercial name for the Technology. We at first provide the research in this paper on the MAC(Medium Access Control)protocols in IEEE802.15.4 WPAN, focus on the MAC sublayer service specification and MAC functionality. Then the discuss of hardware design issues reveals the main elements of the ZigBee transceiver configuration. Finally the MAC sublayer hardware schematic diagram and PCB design are presented, which meet the required goals of this application of ZigBee.First of all, the basic framework of WPAN is built on the basis of the introduction of elements and related conceptions of IEEE802.15.4 WPAN. The services of IEEE802.15.4 MAC are introduced in two types: MAC data service and MAC management service interfacing to the MAC sublayer management entity(MLME)service access point(SAP)(MLME-SAP), and their relationships and messages to support them are also presented. Then the main primitives of MAC data service and MAC management service are illustrated.Secondly, the functional architecture of MAC sublayer is discussed. The whole functional architecture is first introduced, then is the mechanisms for accessing the physical radio channel, including superframe structure and IFS(interframe space). In the succeeding sections, other main functionalities, such as data transfer model, frame structure, robustness, starting and maintaining PANs, etc., are presented respectively.Thirdly, we discuss the architecture and the components of ZigBee device, as well as estimate the hardware design requirements. Since programmable Digital Signal Processor(DSP)are pervasive in wireless communications, considering the lower development costs and lower power consumption characters of DSP, we choose the TI TMS320VC5402 DSP as the core processor in the system. After the introduction of TMS320VC5402 and the software tool--Code Composer Studio(CCS), we bring forth the system design of ZigBee transceiver MAC hardware board based on DSP. Then the main module design methods of the MAC board circuit are described in turn.Finally, the PCB design procedure of ZigBee MAC and the scheme of testing and emulating are discussed. We present the process to generate PCB from schematic, and the principles to be abided in the design of PCB, according to which the layout of MAC PCB, the layer stack structure, and the routing result are achieved. At the end of this paper, the appropriate plan of testing is offered.