Markus Damm

Using transaction level modeling techniques for wireless sensor network simulation

Wireless Sensor Networks are gaining more and more importance in various application fields. Often, energy autonomy on the node level is an essential nonfunctional constraint to be met. Therefore, when simulating such networks, the energy consumption on the node level has to be included into the simulation. To make this time consuming task feasible, an overall simulation speedup on the network level is desirable. In this paper, we propose to use techniques similar to those used in Transaction Level Models of Bus Systems. 1

Connecting SystemC-AMS models with OSCI TLM 2.0 models using temporal decoupling

Recent additions to the system modelling language SystemC, namely SystemC-AMS and OSCI TLM 2.0, provide more efficient ways to model systems within their respective domains. However, most of todaypsilas embedded systems are usually heterogeneous, requiring some way to connect and simulate models from different domains. In this paper we present a first approach on connecting SystemC-AMS models and TLM 2.0 models using temporal decoupling. We show how certain properties of the involved models of computation can be exploited to maintain high simulation performance. Using an example to show the feasibility of our approach, we could also observe a certain tradeoff between simulation performance and accuracy. Further on, we discuss semantical issues and decisions that have to be made, when models are connected. As these decisions are typically application-driven, we propose a converter structure that keeps converters simple but also provides ways to model application-specific behaviour.

A partially decentralised forecast-based demand-side-management approach

This paper presents a demand-side management approach for private homes and small businesses based on wireless sensor/actor nodes controlling appliances, taking into account available local renewable energy resources like wind energy and photovoltaics. An approach for forecasting energy production by a local wind turbine is presented. Forecasts for such local renewable energy producers are preprocessed by a central energy management unit which generates abstract cost functions. The final decision making is then shifted to the sensor/actor nodes, and is based on these cost functions as well as the class of the appliance which is controlled. To this end, electrical appliances are classified appropriately.

Reliability-Aware Power Management of Multi-Core Processors

Long-term reliability of processors is experiencing growing attention since decreasing feature sizes and increasing power consumption have a negative influence on the lifespan. The reliability can also be influenced by Dynamic Power Management (DPM), since it affects the processor’s temperature.

Bridging MoCs in SystemC specifications of heterogeneous systems

In order to get an efficient specification and simulation of a heterogeneous system, the choice of an appropriate model of computation (MoC) for each system part is essential. The choice depends on the design domain (e.g., analogue or digital), and the suitable abstraction level used to specify and analyse the aspects considered to be important in each system part. In practice, MoC choice is implicitly made by selecting a suitable language and a simulation tool for each system part. This approach requires the connection of different languages and simulation tools when the specification and simulation of the system are considered as a whole. SystemC is able to support a more unified specification methodology and simulation environment for heterogeneous system, since it is extensible by libraries that support additional MoCs. A major requisite of these libraries is to provide means to connect system parts which are specified using different MoCs. However, these connection means usually do not provide enough flexibility to select and tune the right conversion semantic in a mixed-level specification, simulation, and refinement process. In this article, converter channels, a flexible approach for MoC connection within a SystemC environment consisting of three extensions, namely, SystemC-AMS, HetSC, and OSSS+R, are presented.

TR-FSM: Transition-Based reconfigurable finite state machine

Finite State Machines (FSMs) are a key element of integrated circuits. Hard-coded FSMs do not allow changes after the ASIC production. While an embedded FPGA IP core provides flexibility, it is a complex circuit, requires difficult synthesis tools, and is expensive. This article presents and evaluates a novel architecture that is specifically optimized for implementing reconfigurable finite state machines: Transition-based Reconfigurable FSM (TR-FSM). The architecture shows a considerable reduction in area, delay, and power consumption compared to FPGA architectures with a (nearly) FPGA-like reconfigurability.

Shifting of thermal and schedulable loads based on abstract cost profiles

This paper presents a demand-side management approach based on cost profiles which are abstract in the sense that they not represent monetary costs, but aggregate information from several sources like tariffs, wind forecast or grid operator demand control signals. In particular, it is shown how these cost profiles are used for local control of thermal (e.g. freezers) and schedulable loads (e.g. washing machines). Also, different variants for the global control in terms of protocols are discussed where a central energy management unit compiles these cost profiles depending not only on outside information, but also on load forecasts and load plans compiled locally at the appliances.

A Smartcard based approach for a secure energy management node architecture

Future buildings and neighborhoods are expected to combine a manifold of Energy using Products (“EuP”) ranging from electrical lighting to HVAC with locally available renewable energy sources and energy storages. Until now, advanced techniques for energy management are not yet applicable in an economically reasonable way in the smaller entities like in energy-positive buildings and neighborhoods. The EC FP7 project SmartCoDe is trying to enable a low cost application for demand side management and smart metering in private homes and small commercial buildings and neighborhoods. A new system architecture for secure wireless energy management nodes that specifically considers the requirements of Energy using Products in homes/offices is developed. The focus is the development of an inexpensive wireless System in Package (SiP) solution that allows to build up a fine grained infrastructure of wireless connected Energy using Products. The proposed architecture is a smartcard based solution which is scalable, highly secure, cheap and does not complicate node integration.1

A dedicated reconfigurable architecture for finite state machines

For ultra-low-power sensor networks, finite state machines are used for simple tasks where the system’s microprocessor would be overqualified. This allows the microprocessor to remain in a sleep state, thus saving energy. This paper presents a new architecture that is specifically optimized for implementing reconfigurable Finite State Machines: Transition-based Reconfigurable FSM (TR-FSM). The proposed architecture combines low use of resources with a (nearly) FPGA-like reconfigurability.

Co-Simulation of mixed HW/SW and Analog/RF systems at architectural level

Analog systems are more and more functionally interwoven with digital hardware/software systems. SystemC offers the potential for a unified modeling approach for such systems: SystemC AMS extensions and SystemC TLM extensions are covering the domains of analog/signal processing systems, resp. hardware/software systems. Both extensions use different Models of Computation to gain simulation performance, most notably by abstracting timing information. In this paper we present a method to couple SystemC AMS extensions with TLM 2.0 extensions while maintaining the simulation speedup for an overall system simulation.