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 …

I and i

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.

Survey of Wireless Indoor Positioning Techniques and Systems

National Institute of Standards and Technology における超伝導研究及び生活

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.

The LED block cipher

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).

/pdf/katan-and-ktantan-a-family-of-small-and-efficient-hardware-1nbl4htw1x.pdf

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

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.

Information server for bus operators

A management system for home area networks has been developed. The main design targets have been to support heterogeneous network technologies, automate the network configuration and management, and to enable application based Quality of Service support. The resulting system architecture has a five-layer functional architecture and a centralised topology with a management server. Also, the support of new proprietary management functionality has been designed for wireless access points and client terminals. A wireless LAN and Java based prototype of the management system is being implemented and its architecture presented.

https://link.springer.com/content/pdf/10.1007%2F978-3-540-45209-6_153.pdf

Design of a management system for wireless home area networking

Generally, a sensor node refers to any device that is capable to sense its environment. Wireless Sensor Network (WSN) as a technology is a collection of sensor devices that co-operate with each other. A WSN may comprise even thousands of autonomic and self-organizing nodes that combine environmental sensing, data processing, and wireless multihop ad-hoc networking. The features of WSNs enable monitoring, object tracking, and control functionality. The potential applications include environmental and condition monitoring, home automation, security and alarm systems, industrial monitoring and control, military reconnaissance and targeting, and interactive games.

Low-power WSN Technology

Evaluating the model accuracy in automated design space exploration

The Specification and Description Language (SDL) for implementing embedded digital signal processor (DSP) applications has been studied for developing a wireless local area network (WLAN) demonstrator. The main DSP application is the medium access control (MAC) protocol. The protocol has been implemented using SDL and is being ported into the DSP of the demonstrator platform. C source code is automatically generated from the formal SDL model and compiled to build an executable protocol application. For the SDL-to-C conversion, a commercial development tool has been utilised. The tool provides a special converter for smaller scale systems. The converter can be scaled and optimised according to the properties of the source SDL model. By careful manual optimisation, the protocol performance and size requirements are improved.

Marko Hännikäinen

Papers

Information server for bus operators

Design of a management system for wireless home area networking

Low-power WSN Technology

Evaluating the model accuracy in automated design space exploration

SDL-to-C conversion for implementing embedded WLAN protocols