Marko Hännikäinen

Bio: Marko Hännikäinen is an academic researcher from Tampere University of Technology. The author has contributed to research in topics: Wireless sensor network & Wireless network. The author has an hindex of 27, co-authored 128 publications receiving 3061 citations.

Robust tree construction and maintenance for global time synchronization protocols in Wireless Sensor Networks

Abstract: The dynamic and resource constrained nature of Wireless Sensor Networks (WSNs) require that the time synchronization protocol is highly fault tolerant whilst minimizing communication overhead for energy-efficiency In current tree-based WSN synchronization protocols, the tree fault tolerance is not considered at all or incurs a significant messaging overhead In this paper, we present a robust Synchronization TREE construction and maintenance protocol (S-TREE) It can handle failed nodes and communication links, and intermittent connectivity It is integrated to the inherent neighbor discovery to minimize communication overhead The S-TREE protocol minimizes the accumulated synchronization error of any given neighbor clock estimation technique by using minimum hop paths to the reference node The protocol performance is analyzed mathematically For an example scenario of 1000 nodes S-TREE reduces communication overhead to 6% in tree construction and to 10% in remote clock estimation compared to flooding which is commonly used in related protocols

Embedding SDL implemented protocols into DSP

Abstract: Specification and Description Language (SDL) is an efficient tool for specifying and implementing complex real time systems, such as communications protocols. A Medium Access Control (MAC) protocol for a Wireless Local Area Network (WLAN) has been implemented using the language. The source C code for the protocol application is automatically generated from SDL. In this paper, the embedding of the generated protocol into a Digital Signal Processor (DSP) is described. As the high abstraction SDL model does not contain any dependencies to the target operational environment the application is adapted to DSP using tailored environment functions. These functions convert the asynchronous signalling used inside the SDL system into physical events of the DSP. In addition, as no operating system is used, the environment functions must implement other services required by the SDL generated application, such as platform clock and interrupt handling.

Design of a manageable WLAN Access Point

Abstract: This paper presents the design and prototype implementation of a manageable WLAN Access Point (mAP). mAP has been developed for managing WLAN Quality of Service (QoS), frequency selection, client configuration, and for collecting a wide range of management information. The prototype is implemented using a Linux platform. With the presented architecture, the mAP functionality can be easily extended by adding new management functions and automated services.

Information server for bus operators

Abstract: TUTPIS is a large-scale information system being developed for companies that provide public transport services and their customers. TUTPIS is targeted for national services, concerning taxis, buses, and trains as the main means of conveyance. This paper presents the functionality and implementation of a TUTPIS server targeted for bus operators. The server receives real-time information through cellular data network from active buses, processes the received data, and produces different types of reports for TUTPIS users. An operational TUTPIS server has been implemented. The implementation is made on Linux PCs using the Java 2 Enterprise Edition (J2EE). The TUTPIS server has been evaluated in practice with a limited number of buses in Finland during the fall 2002. In addition, performance testing has been carried out to find out the capacity of TUTPIS platform. These tests have shown that the server provides adequate performance for TUTPIS services. The server development continues by extended functionality for both bus operators and passengers.

I and i

Abstract: There is, I think, something ethereal about i —the square root of minus one. I remember first hearing about it at school. It seemed an odd beast at that time—an intruder hovering on the edge of reality. Usually familiarity dulls this sense of the bizarre, but in the case of i it was the reverse: over the years the sense of its surreal nature intensified. It seemed that it was impossible to write mathematics that described the real world in …

Survey of Wireless Indoor Positioning Techniques and Systems

Abstract: Wireless indoor positioning systems have become very popular in recent years. These systems have been successfully used in many applications such as asset tracking and inventory management. This paper provides an overview of the existing wireless indoor positioning solutions and attempts to classify different techniques and systems. Three typical location estimation schemes of triangulation, scene analysis, and proximity are analyzed. We also discuss location fingerprinting in detail since it is used in most current system or solutions. We then examine a set of properties by which location systems are evaluated, and apply this evaluation method to survey a number of existing systems. Comprehensive performance comparisons including accuracy, precision, complexity, scalability, robustness, and cost are presented.

The LED block cipher

Abstract: We present a new block cipher LED. While dedicated to compact hardware implementation, and offering the smallest silicon footprint among comparable block ciphers, the cipher has been designed to simultaneously tackle three additional goals. First, we explore the role of an ultra-light (in fact non-existent) key schedule. Second, we consider the resistance of ciphers, and LED in particular, to related-key attacks: we are able to derive simple yet interesting AES-like security proofs for LED regarding related- or single-key attacks. And third, while we provide a block cipher that is very compact in hardware, we aim to maintain a reasonable performance profile for software implementation.

KATAN and KTANTAN -- A Family of Small and Efficient Hardware-Oriented Block Ciphers

Abstract: In this paper we propose a new family of very efficient hardware oriented block ciphers. The family contains six block ciphers divided into two flavors. All block ciphers share the 80-bit key size and security level. The first flavor, KATAN, is composed of three block ciphers, with 32, 48, or 64-bit block size. The second flavor, KTANTAN, contains the other three ciphers with the same block sizes, and is more compact in hardware, as the key is burnt into the device (and cannot be changed). The smallest cipher of the entire family, KTANTAN32, can be implemented in 462 GE while achieving encryption speed of 12.5 KBit/sec (at 100 KHz). KTANTAN48, which is the version we recommend for RFID tags uses 588 GE, whereas KATAN64, the largest and most flexible candidate of the family, uses 1054 GE and has a throughput of 25.1 Kbit/sec (at 100 KHz).