A Complete System-level Behavioural Model for IEEE 802.15.4 Wireless Sensor Network Simulations D. Navarro, W. Du, F. Mieyeville, F. Gaffiot Université de Lyon, Institut des Nanotechnologies de Lyon (INL) UMR5270 - CNRS, Ecole Centrale de Lyon, Ecully, F-69134, France Abstract— This paper presents a complete SystemC-based Wireless Sensor Network model. It implements the entire IEEE 802.15.4 standard, and permits to simulate scenarios at high level, taking hardware and software low level parameters into account, also enabling design space exploration for system level designers. I. INTRODUCTION A Wireless Sensor Network (WSN) is a large-scale network of resource-constrained sensor nodes that are deployed at different locations. Limited resources are of different kinds: energy, memory and processing. Wireless Sensor Networks are now well known and used systems in a variety of applications, such as environmental data collection, security monitoring, logistics or health [1]. The sensor nodes cooperatively monitor physical or environmental conditions, such as temperature, sound, vibration or pressure. They are typically composed of one or more sensors, an 8-bit or 16-bit microcontroller, a non-volatile memory, a radiofrequency transceiver and an energy supply. Brand examples of most used devices are: ATMEL, Texas Instruments or Microchip microcontrollers and Texas Instruments, ATMEL, Freescale, or ST-Microelectronics radiofrequency transceivers. Linux systems composed of 32-bit RISC processors exist – like the well known Crossbow's Stargarte platform- but energy consumption is prohibitive and autonomy is largely affected, thus relegating these products to the border of the WSN field. We do not consider such systems, and we focus on several months of battery life systems. Interconnect level in Wireless Sensor Networks are inspired from wireless telecommunication networks, whose topologies and network hierarchy can be complex. Most of platforms use IEEE 802.15.4 standard [2], sometimes with the ZigBee [3] or MiWi [4] over-stack. IEEE 802.15.4 standard defines the two OSI lower layers: the physical (PHY) layer and the medium access control (MAC) layer. ZigBee provides the network layer and the framework for the application layer. Although complex topologies exist, such networks are dedicated to low power and low data rate applications, mainly for physical and environmental remote measurements. In many cases, it is difficult to design such a network at system level, because low level (at sensor node) hardware and software considerations are mandatory. CAD tools are also required to make system-level (hardware and software) simulations, taking low-level parameters into account. Moreover, Wireless Sensor Networks are heterogeneous systems, their simulation and design is also a difficult task. We propose a complete SystemC-based Wireless Sensor Network model that can support and simulate different hardware devices. It implements the entire IEEE 802.15.4 standard. II. WIRELESS SENSOR SIMULATORS Many simulators have been developed last few years [5-9]. Unfortunately, most of them are restricted to specific hardware or precisely focus on either network level or node level. Research on sensor network evaluation can be broadly divided in two categories: network simulators enhanced with node models, and node simulators enhanced with network models. The network simulators refer to the general purpose network simulator, such as Network Simulator NS-2 [8] and OMNeT++ [9] (and their declinations). The problem is these interesting network simulators are not sensor platform specific and they are also too high level for hardware considerations. Moreover, there is no separation between computation and communication models. That modeling is also not suitable for hardware replacements and explorations, and it is not part of a electronic design flow. Then, such simulators don't have accurate energy models [12]. Node simulators refer to precise hardware description, with a synchronization strategy among the nodes, such as Avrora [10], or SCNSL - SystemC Network Simulation Library [11]. These simulators are better suited for embedded system designers, requiring precise low level models for top- down (network to node) approach. SCNSL is a networked embedded systems simulator, written in SystemC and C++. SystemC is widely used in network community. Because SystemC is a C++ class library, it has the advantage to be able to model hardware, software, and network. SCNSL contains three modules: node (in SystemC), node-proxy (in SystemC) and network (in C++). 978-1-4244-5309-2/10/$26.00 ©2010 IEEE 3917