One of the main problems that CPS designers face is “the lack of simulation tools and models for system design and analysis”. Even in the Wireless Sensor Network (WSN) field, which can be considered a subset CPS (e.g. a CPS can, among others, comprise of a set of WSNs), it has been reported that over one third of the researchers use a testbed in the design process while more than an additional quarter of them design their own WSN simulator in order to model their system as a result of the severe limitations of all the existing solutions. This is mainly because the majority of the existing simulation tools handle efficiently only parts of the CPS (for example only the processing nodes or the network) while they mainly focus on the performance of the CPS. Moreover, the existing simulators need extreme amounts of processing resources and computation time to simulate a system at a low level (when simulating the execution of the complete software stack, including the Operating System, in a target platform at a close to cycle accurate level). Faster approaches are available however they function at higher levels of abstraction and cannot provide the precision and accuracy that are necessary in order to model the exact behavior of a system under design so as to guarantee that it meets its requirements.
COSSIM will address all those important needs by providing a novel open-source framework which can
- seamlessly simulate, in an integrated way, both the networking and the processing parts of the CPS,
- perform the simulations orders of magnitude faster,
- provide significantly more accurate results, especially in terms of power consumption, than existing solutions
- report the, critical for many applications, security levels of the simulated CPS.
COSSIM will achieve the above by incorporating a full system simulator (i.e. “a simulator that simulates an electronic system at such a level of detail that complete software stacks from real systems can run on the simulator without any modification”) with a novel network simulator. Furthermore, novel power consumption and security models will be developed and integrated to the proposed framework. Additionally, COSSIM will create a framework that is orders of magnitude faster than existing solutions, by applying hardware acceleration through the use of field programmable gate arrays (FPGAs), which have been proven extremely efficient in relevant tasks.
The Figure above provides an overview of the CPS simulation framework as proposed by COSSIM. The following figure depicts the low-level architecture of the proposed framework.
In order to create such a novel framework addressing the requirements of the CPS designers, there are some clear and measurable objectives that will be met.
- Objective 1: Develop an open-source simulation framework backed by a large community that can, for the first time, simulate a complete CPS comprising of CPS nodes incorporating multi-core CPUs, complex accelerators and peripherals, and interconnected with complex and heterogeneous networks
- Objective 2: Accelerate simulation of complex CPS by more than one, and most probably two, orders of magnitude when compared with the existing solutions
- Objective 3: Provide at least 50% more accurate power estimations than existing solutions
- Objective 4: Support for the first time in a CPS tool security features/levels as aspects of the system simulation
- Objective 5: Simulate two real-world applications from different domains so as to demonstrate all the above unique features in highly demanding commercial environments