PicoRadio is a ubiquitous network of ultra low-power and low-cost wireless sensor nodes. Each node contains a complete protocol stack based upon the OSI model. My research is on implementing the medium access control (MAC) layer of this stack. Its functionality includes initialization and maintenance management, such as assigning local address, keeping one-hop network topology, and processing control broadcast messages and datapath between the network layer and physical layer for broadcast and unicast messages with FIFO buffers. MAC also uses CSMA and beaconing mechanisms. It discovers neighbors in the initialization phase, maintains a neighbor lookup table, forwards the neighbor information to the network layer, keeps a list of two-hop neighbors’ addresses, assigns its own local address randomly, computes its own location, maintains on a periodical basis, issues random backoff, designates channel for transmission, etc. In order to capture the functionality of the MAC, Stateflow in Simulink is chosen as the implementation tool. The underlying model of computation is suitable for simulation of control-dominated applications like the MAC. We have been focusing on functional simulations for a PicoNode network in Simulink for the purpose of protocol validation and verification. Current effort has been done on system design using Simulink Stateflow. Issues in the development of the MAC layer such as power management, power control, and CSMA sensing method are considered. Stateflow has been converted into VHDL using SSHAFT Translator. VHDL verification will be done in BEE. Automatic synthesis using SSHAFT design flow down to ASIC will be used to complete this project.
Figure 1: Design flow