Showing papers by "Marko Hännikäinen published in 2011"

Multicore Communications API (MCAPI) implementation on an FPGA multiprocessor

Abstract: The design and implementation of an application programming interface (API) is a trade-off between abstraction it provides and overheads it causes. This paper presents an implementation of Multicore Communications API (MCAPI) on a heterogeneous platform consisting of FPGA-based multiprocessor system-on-chip (MPSoC) connected via PCIe to an external CPU board. The purpose is to provide a unified programming API to different processor and OS types as well as hardware IP-blocks. MCAPI is shown to meet these requirements. We show the MCAPI transport implementation on three processors and two buses, measure the overhead cost, and analyze the effort required to port an application from a PC to the MPSoC. The measured library memory footprint is less than 25KB and the roundtrip communication latency is diminishing low — only few dozen clock cycles — compared to non-MCAPI implementation.

A wireless sensor network for hospital security: from user requirements to pilot deployment

Abstract: Increasing amount of Wireless Sensor Network (WSN) applications require low network delays. However, current research on WSNs has mainly concentrated on optimizing energy-efficiency omitting low network delays. This paper presents a novel WSN design targeted at applications requiring low data transfer delays and high reliability. We present the whole design flow from user requirements to an actual pilot deployment in a real hospital unit. The WSN includes multihop low-delay data transfer and energy-efficient mobile nodes reaching lifetime of years with small batteries. The nodes communicate using a low-cost low-power 2.4GHz radio. The network is used in a security application with which personnel can send alarms in threatening situations. Also, a multitude of sensor measurements and actuator control is possible with the WSN. A full-scale pilot deployment is extensively experimented for performance results. Currently, the pilot network is in use at the hospital.

Kactus2: Environment for Embedded Product Development Using IP-XACT and MCAPI

Abstract: Key challenge for embedded system companies is management of product configurations over lifecycle. Either new functionality is implemented on an old platform, legacy code on a new one, or both at the same time. We propose Kactus2, a product integration environment suitable for small and mid-size enterprises (SME) utilizing FPGAs. We combine IP-XACT for HW integration and Multicore Association Communications API (MCAPI) for SW integration. The programmer has a uniform view of the system as MCAPI nodes regardless of their implementation in SW or HW. Kactus2 is a work-in-progress open source project implemented in C++ and QT 4.7 currently containing over 40k lines of code and gSOAP as TGI IP-XACT interface.

Range-free algorithm for energy-efficient indoor localization in Wireless Sensor Networks

Abstract: Wireless Sensor Networks (WSNs) form an attractive technology for ubiquitous indoor localization. The localized node lifetime is maximized by using energy-efficient radios and minimizing their active time. However, the most low-cost and low-power radios do not include Received Signal Strength Indicator (RSSI) functionality commonly used for RF-based localization. In this paper, we present a range-free localization algorithm for localized nodes with minimized radio communication and radios without RSSI. The low complexity of the algorithm enables implementation in resource-constrained hardware for in-network localization. We experimented the algorithm using a real WSN implementation. In room-level localization, the area was resolved correctly 96% of the time. The maximum point-based error was 8.70 m. The corresponding values for sub-room-level localization are 100% and 4.20 m. The prototype implementation consumed 1900 B of program memory. The data memory consumption varied from 18 B to 180 B, and the power consumption from 345 μW to 2.48 mW depending on the amount of localization data.

Link quality-based channel selection for resource constrained WSNs

Abstract: Wireless Sensor Networks (WSN) consist of autonomous and intelligent nodes that combine sensing, actuation, and distributed computing with small size and low energy One of the major issues is overcoming the non-ideality of unreliable real-world wireless links and avoiding interferences This paper presents a link quality-based lightweight channel selection mechanism that discovers low interference and lightly loaded channels, thus improving latency, reliability, and throughput The mechanism grades a channel from link reliability and changes the channel on interference The proposed selection is suitable for resource and energy constrained WSNs as it does not require any extra communication or channel sensing The channel selection is implemented with a low energy 24GHz multihop mesh WSN using 1mW transmission power In practical measurements in a typical office environment with 100mW WLAN interference, the selection had 96% average link reliability compared to the 84% of randomized channel selection

Meta-Model and UML Profile for Requirements Management of Software and Embedded Systems

Abstract: Software and embedded system companies today encounter problems related to requirements management tool integration, incorrect tool usage, and lack of traceability. This is due to utilized tools with no clear meta-model and semantics to communicate requirements between different stakeholders. This paper presents a comprehensive meta-model for requirements management. The focus is on software and embedded system domains. The goal is to define generic requirements management domain concepts and abstract interfaces between requirements management and system development. This leads to a portable requirements management meta-model which can be adapted with various system modeling languages. The created meta-model is prototyped by translating it into a UML profile. The profile is imported into a UML tool which is used for rapid evaluation of meta-model concepts in practice. The developed profile is associated with a proof of concept report generator tool that automatically produces up-to-date documentation from the models in form of web pages. The profile is adopted to create an example model of embedded system requirement specification which is built with the profile.

Applying IP-XACT in product data management

Abstract: Key challenge for industrial embedded system companies is product data management (PMD) of rapidly changing requirements, new platforms and own legacy intellectual property This can be alleviated with IP component reuse methods, platform based design, and Model Driven Development (MDD) methodologies We propose an open source product integration environment suitable for small and mid-size enterprises (SME) utilizing FPGAs We extend the use of IP-XACT standard from HW integration at IP-level to board and chip level designs, describe SW as IP-XACT metadata objects, and add reusability status to objects for PDM We do not modify or extend IP-XACT metadata format to maintain compatibility with standard compliant tools Instead, we propose naming conventions and usage profiles An exemplar FPGA-product shows feasibility in practice in our Kactus2 tool The benefits are covering complete products including SW objects and HW/SW mappings while strictly keeping the standard XML format

Practical monitoring and analysis tool for WSN testing

Abstract: Wireless Sensor Networks (WSN) comprise autonomous embedded nodes that combine sensing, actuation, and distributed computing with small size and low energy. Testing of WSNs is challenging due to distributed functionality, lack of test and debug interfaces, and limited communication, computation and memory resources. This paper presents the design and implementation of a practical network monitoring and analysis tool for identifying the causes of misbehavior. The tool consists of a sniffer node that passively captures WSN traffic, and multiple user interfaces that can run e.g. on a PC or mobile phone. Unlike the related proposals, our tool neither needs setting up an additional monitoring network alongside the actual WSN nor uses any node resources. Practical testing experiences with mul-tihop mesh WSN deployments show that the tool reveals design and implementation defects that are hard to discover with other testing methods such as in-network monitoring systems or debug prints.

Remote diagnostics and performance analysis for a wireless sensor network

Abstract: Wireless Sensor Networks (WSNs) comprise embedded sensor nodes that operate autonomously in a multi-hop topology. The challenges are unreliable wireless communications, harsh environment, and limited energy and computation resources. To ensure the desired level of service, it is essential to diagnose performance issues e.g. due to low quality links or energy depletion. This paper presents remote diagnostics and performance analysis that comprise self-diagnostics on embedded sensor nodes, the remote collection of diagnostics, and the design of a diagnostics analysis tool. Unlike the related proposals, our approach allows correcting detected problems by identifying the reasons for misbehavior. The diagnostics is verified with a practical WSN implementation. It has only a small overhead, less than 18 B/min per node in the implementation, allowing the use in bandwidth and energy constrained WSNs.

Positioning in Synchronized Ultra Low-Power Wireless Sensor Networks

Abstract: Wireless Sensor Networks (WSNs) consist of densely deployed, independent, and collaborating low cost sensor nodes. The nodes are highly resource-constrained in terms of energy, processing, and data storage capacity. Thus, the protocols used in WSNs must be highly energy-efficient. WSN communication protocols achieving the lowest power consumption minimize radio usage by accurately synchronizing transmissions and receptions with their neighbors. In this paper, we show how network signaling frames of state-of-the-art synchronized communication protocols for low-power WSNs supporting mobile nodes can be used for positioning. We derive mathematical models for node power consumption analysis. Both centralized and distributed positioning architectures are modeled. The models provide a tool for estimating what kind of network lifetimes can be expected when average positioned node speed, the amount of anchor nodes required by the location estimation algorithm, and the location refresh rate required by the application are known. The presented analysis results are based on two kinds of node hardware: with and without Received Signal Strength Indicator (RSSI). The results show that the positioning parameters and used hardware have significant impact on node power consumption and network lifetime. In the presented results, the network lifetime ranges from over 10 years to 2 months with different positioning requirements and hardware. keywords: Wireless, Low-Power, Sensor Networks c ⃝[2010] IEEE. Portions reprinted, with permission, from [Ville Kaseva, Timo D. Hamalainen, and Marko Hannikainen, Positioning in Resource-Constrained Ultra Low-Power Wireless Sensor Networks, Ubiquitous Positioning Indoor Navigation and Location Based Service (UPINLBS), October/2010]