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Papers - Mitsugi, Jin

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EPC based internet of things architecture

Hada Hisakazu, Mitsugi Jin

527 - 532 2011

The Internet of Things is a concept of connecting small real space physical objects to the Internet using sensor network, RFID, and other forms of wireless network technologies. In this paper, we present an EPC (Electronic Product Code) based Internet of Things (IoT) architecture. The key concept of the architecture is EPC network over heterogeneous access network. We particularly focused on a ZigBee network as it can collect the latest information about 'Things'. The EPC Network provides certain static information about 'Things' such as name and manufacturer. To support end-to-end communication between sensor nodes and applications, Constrained Application Protocol (CoAP) instead of Hyper Text Transfer Protocol (HTTP) over ZigBee is developed. A gateway on a local area network converts HTTP and CoAP. A pseudo Universal Plug and Play (UPnP) protocol supports JOIN/LEAVE management of sensor nodes. We also prove a prototype home appliances management system that adopt our architecture over a ZigBee network. Our prototype provides energy-saving application using home appliances information collected through the system. © 2011 IEEE.

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Group coding of RF tags to verify the integrity of group of objects

Sato Yuki, Mitsugi Jin, Nakamura Osamu, Murai Jun

200 - 206 2011

RFID is an essential technology to uniquely identify physical objects. In many practical business processes using RFID, we check not only individual objects but also check if there is no missing objects and no extra objects in a group of objects. While individual objects identifications are done by using RFID, group verifications are usually done by looking up a shipping list or corresponding EDI data which require a network connection. In this paper, we propose "group coding of RF tags" by which we can verify the integrity of a group of objects just by writing additional data in RF tags' memory. The additional data is computed from unique IDs of objects that belong to the group. We propose fundamental and general group codings. With the fundamental group coding, we can check if the integrity of a group of objects is preserved or not. It is a parity check of hashes of unique IDs in a group. We also propose general group coding by extending the fundamental group coding. With the general group coding, we can estimate the number of missing objects if the integrity of a group is not verified. The strength of the missing number estimation can be controlled by the size of data written to RF tags. It can be considered as a Low Density Parity Check (LDPC) in physical objects. The theory of group coding is confirmed by a numerical simulation and an experiment. It is shown by the simulation and experiment that we can detect 10 missing RF tags out of 20 RF tags with 99.5% reliability by writing 96-bit data into each RF tags besides its 96-bit unique ID. © 2011 IEEE.

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THE INTERNET OF THINGS

Iera, Antonio, Floerkemeier, Christian, Mitsugi, Jin, Morabito, Giacomo

IEEE WIRELESS COMMUNICATIONS 17 ( 6 ) 8 - 9 2010.12

Research paper (scientific journal), ISSN 1536-1284

The Internet of things

Iera Antonio, Floerkemeier Christian, Mitsugi Jin, Morabito Giacomo

IEEE Wireless Communications 17 ( 6 ) 8 - 9 2010.12

ISSN 1536-1284

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Low power and agile sensor data retrieval using dual interface passive RF tag

Sugimoto Kenichi, Mitsugi Jin, Nakamura Osamu, Murai Jun

100 - 105 2010

Consider a situation where one desires to retrieve sensor data from an arbitrary environment via a moving interrogator. Maintenance of street lights and electric apparatus in conduits for example. The fundamental problems with this system have been 1)the trade-off relation between power consumption by sensor and the data retrieval rate for the interrogator, and 2)the data retrieval agility for the moving interrogator. A higher duty ratio incurs more power consumption in sensors whereas a lower duty ratio leads to a less reliable retrieval rate. Even though there have been such efforts as"adaptive sleep period control" which was derived form the packet arrival rate,they didn't systemically solve the problem, particularly for moving-interrogator environment. This paper presents a solution of separating the timing of sensor-sampling and the timing of sensor-data retrieval. The asynchronous data retrieval mechanism is facilitated by a dual interfaced UHF passive RF tag known as a " record tag "which the authors have been developing. This paper examines the power consumption composition of a prototype recorder tag. The power consumption efficiency of the proposed data-retrieval method is discussed in comparison with that of the existing method in term of " Sensor Sampling Interval vs.Battery Life Expectancy"The author also evaluated the viability of retrieving sensor data through a moving-interrogator. We specifically inspected the relationship of " Interrogator's moving Speed vs Successful Data Retrieval Rate "The tests showed that with a commercial 1.2V rechargeable battery, the recorder tag lasts for 21 days forluminance and temperature sensing using a 30 minute samplinginterval, extending the traditional battery lifespan ten times longer, yet still preserving 100% time availability for sensor data retrieval. The power consumption is expected to be eight times as efficient when using optimized circuitry. Experiments in an emulated fading environment reveal that the data retrieval rate is observed to be the highest when the maximum relative speed between the moving-interrogator and the recorder tag is less than 3km/h, with an optimized distance of separation being 10cm for a 27dBm EIRP interrogator. The moving speed, 3km/h, can be improved by optimizing the anti-collision procedure and by enhancing the sensitivity of the recorder tag. © 2010 IEEE.

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1000-RF-tag emulation with an 8bit micro processor

Kamiya Naoyasu, Mitsugi Jin, Sugimoto Kenichi, Nakamura Osamu, Murai Jun

350 - 355 2010

UHF band passive RFID is an essential identification technology in pervasive computing world. One of the industrial demands to UHF band passive RFID is fast reading of many RF tags. This is particularly relevant for item-level-tagging of CDs, DVDs, books and consumer electronics. Many high-speed MAC protocols have been proposed thus far. Quantitative evaluation of reading speed, however, is not easy because we need to lay out many RF tags and measure the reading durations usually through interrogator APIs, which differ from interrogator to interrogator. In this paper, the authors propose two efficient multiple RF tag emulation algorithms which leverage the probabilistic nature of MAC protocol. We have implemented the algorithms onto a programmable battery assisted passive tag (BAP), equipped with an 8bit micro processor and evaluated the reading speed of commercial interrogators. It was revealed that the BAP can efficiently emulate the behavior of more than 1000 Gen2 RF tags for the reading speed evaluation with a trivial penalty on accuracy. ©2010 IEEE.

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2010 Internet of Things, IoT 2010

Michahelles Florian, Mitsugi Jin, Murai Jun

Unknown Journal 2010

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Avoidance method of interference between RFID systems including interference-zone change according to the distance between channels

Uryu Akira, Umeda Yohtaro, Takyu Osamu, Mitsugi Jin

204 - 207 2010

In a long-range RFID system, the communication range is far longer than that in a conventional short-range RFID system. However, the long-range RFID system tends to suffer interfering problem between systems. In this report, we evaluate the interference avoidance method of assigning the frequency channels and time slots to reader with using the information of the reader position. From the computer simulation, we show that the number of required time slots for avoiding the interference can be reduced and the frequency utilization efficiency can be increased when the dependence between the interference geometrical distance between readers and the frequency distance between channels is taken into account. © 2010 IEEE.

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Efficient Frequency Sharing of Baseband and Subcarrier Coding UHF RFID Systems

Mitsugi, Jin, Kawakita, Yuusuke

IEICE TRANSACTIONS ON COMMUNICATIONS E92B ( 12 ) 3794 - 3802 2009.12

Research paper (scientific journal), ISSN 0916-8516

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Efficient frequency sharing of baseband and subcarrier coding UHF RFID systems

Mitsugi Jin, Kawakita Yuusuke

IEICE Transactions on Communications E92-B ( 12 ) 3794 - 3802 2009

ISSN 0916-8516

UHF band passive RFID systems are being steadily adopted by industries because of their capability of long range automatic identification with passive tags. For an application which demands a large number of readers located in a limited geographical area, referred to as dense reader mode, interference rejection among readers is important. The coding method, baseband or subcarrier coding, in the tag-to-reader communication link results in a significant influence on the interference rejection performance. This paper examines the frequency sharing of baseband and subcarrier coding UHF RFID systems from the perspective of their transmission delay using a media access control (MAC) simulator. The validity of the numerical simulation was verified by an experiment. It is revealed that, in a mixed operation of baseband and subcarrier systems, assigning as many channels as possible to baseband system unless they do not exploit the subcarrier channels is the general principle for efficient frequency sharing. This frequency sharing principle is effective both to baseband and subcarrier coding systems. Otherwise, mixed operation fundamentally increases the transmission delay in subcarrier coding systems. Copyright © 2009 The Institute of Electronics, Information and Communication Engineers.

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A practical method for UHF RFID interrogation area measurement using battery assisted passive tag

Mitsugi, Jin, Tokumasu, Osamu

IEICE TRANSACTIONS ON COMMUNICATIONS E91B ( 4 ) 1047 - 1054 2008.04

Research paper (scientific journal), ISSN 0916-8516

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A tamper detection method for RFID tag data

Yamamoto Akira, Suzuki Shigeya, Hada Hisakazu, Mitsugi Jin, Teraoka Fumio, Nakamura Osamu

51 - 57 2008

Recently, system designers, especially in the field of product life-cycle management system start considering use of user memory bank of UHF RFID tags. By storing most useful life-cycle data onto a tag, user can access to the data even without access to back-end databases. One of the major issues to make use of the user memory bank is detection of memory tampering. Although technology vendors start introducing new functionalities such as fine grained locking along with high capacity user memory, these tags with new functionalities require new non-standardized air protocol to operate - require modified version of reader/writers. Also, these tags are usually more expensive. In this paper, we introduce a novel approach to this problem: tag side write journaling mechanism and "Tag Memory Cloaking," which protect the journal by using. Tag Private Memory region, which is only readable and not writable from external devices such as a reader/writer, but writable by tag itself. Also, any write to the user memory automatically add journal entry - offset and length of the write - into the Tag Private Memory region. Later, a user can check existence of overlapped writes to user memory by checking the journal records. Since we have not modified any of air protocol, standard compliant read/writer can fully capable of all of our proposed operations: write to the tag, read, then detect unusual modification to user memory area. We have implemented the functionality to Programmable Battery Assisted Passive tag (BAP), then validated the method with several standard compliant reader/writers. © 2008 IEEE.

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Generalized handling of user-specific data in networked RFID

Osaka Kosuke, Mitsugi Jin, Nakamura Osamu, Murai Jun

173 - 183 2008

As RFID technology has been widely adopted, it has been acknowledged that user-specific data carrying RFID tags can be conveniently used. Since the typical user-specific data is sensor data, some existing studies have proposed new RFID architectures for sensor data handling. However, there are industrial demands to include non-sensor data, such as sales records, repair history, etc., as well as sensor data in the purview of our study. To realize handling of such general user-specific data, we need to satisfy requirements such as the minimum set of data semantics required to access the user-specific data, flexible user-specific data memory schema determination and partial collection of user-specific data. For this purpose, we designed the role of "session manager", which communicates with associate applications and notifies an interrogator what to do upon retrieval of a unique identification number. The session manager with the structured user-specific data can provide flexible collection and processing of user-specific data in the networked RFID. Since the fundamental drawback of the session manager might be the lookup overhead, we examined the overhead with a simulation based on experimental data. It was revealed that the overhead is equivalent to and in some cases even better than that of the existing method, which relies on structural tag memory. © 2008 Springer-Verlag Berlin Heidelberg.

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A practical method for UHF RFID interrogation area measurement using battery assisted passive tag

Mitsugi Jin, Tokumasu Osamu

IEICE Transactions on Communications E91-B ( 4 ) 1047 - 1054 2008

ISSN 0916-8516

For the success of a large deployment of UHF RFID, easyto-use and low-cost engineering tools to facilitate the performance evaluation are demanded particularly in installations and for trouble shooting. The measurement of interrogation area is one of the most typical industrial demands to establish the stable readability of UHF RFID. Exhaustive repetition of tag position change with a read operation and a usage of expensive measurement equipment or special interrogators are common practices to measure the interrogation area. In this paper, a practical method to measure the interrogation area of a UHF RFID by using a battery assisted passive tag (BAP) is presented. After introducing the fundamental design and performances of the BAP that we have developed, we introduce the measurement method. In the method, the target tag in the target installation is continuously traversed either manually or automatically while it is subjected to a repetitive read of a commercial interrogator. During the target tag traversal, the interrogator's commands are continuously monitored by a BAP. With an extensive analysis on interrogator commands, the BAP can differentiate between its own read timings and those of the target tag. The read timings of the target tag collected by the BAP are recorded synchronously with the target tag position, yielding a map of the interrogation area. The present method does not entail a measurement burden. It is also independent of the choice of interrogator and tag. The method is demonstrated in a practical UHF RFID installation to show that the method can measure a 40 mm resolution interrogation area measurement just by traversing the target tag at a slow walking speed, 300 mm/sec. Copyright © 2008 The Institute of Electronics, Information and Communication Engineers.

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RFID in Japan

Inaba Tatsuya, Mitsugi Jin, Murai Jun, Konomi Shin'ichi

405 - 413 2007.04

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Next-generation broadband mobile satellite communication system in the ubiquitous network era

Ueba Masazumi, Ohata Kohei, Mitsugi Jin

NTT Technical Review 5 ( 1 ) 34 - 44 2007.01

ISSN 1348-3447

After investigating the potential market for satellite communications in around 2010 that will have advantages over future terrestrial communication networks, we concluded that there will be a large demand for broadband communications services for passengers in vehicles such as long-haul trains, seagoing vessels, and airplanes. In this article, we describe a next-generation broadband scalable mobile satellite communication system for Japan that can offer economical broadband Internet service for passengers in such vehicles. We describe possible services, estimate the potential market, and discuss the requirements for such services to flourish. Finally, we discuss enabling technologies required for the system.

Activity weather

Tanaka Hiroya, Kamiyama Yusuke, Tamamura Koga, Kinase Ryo, Mitsugi Jin, Hada Hidekazu

1 - 14 2007

Radio frequency identification (RFID) technology is now widely used for tracking a great variety of objects in spatio-temporal dimensions. In the field of urban management and analysis, personal RFID is a powerful tool for tracing both individual pedestrians and crowd dynamics. In this research, we have focused our attention on how public services can use RFID technology, especially from the viewpoint of attractive and real-time visualization. In a trial demonstration, we installed nine RFID-reader gates in an urban district and provided hundreds of passive RFID-tags to pedestrians. Using this basic RFID-infrastructure, we developed a public display service which visualized and reported urban activities in the style of a real-time weather map. A large display shows the density of people at each location by using geometric contour lines and virtual clouds. Accumulated data is automatically updated and the 'weather' map quickly changes as time passes. The weather-like visualization helps the user understand the dynamics, flows, and trends of crowds, and promotes intuitive forecasting of urban activity.

Multipath identification using steepest gradient method for dynamic inventory in UHF RFID

Mitsugi Jin, Shibao Yu

2007

UHF passive RFID has been already in practice. Industrial applications sometimes suffer insufficient tag readability. Engineering may be needed to enhance the readability, accordingly. One of the factor to deteriorate the readability is the multipath fading. Identification of principal reflecting paths is essential to improve the readability deterioration by, for example, using antenna diversity and usage of microwave absorbance materials to suppress reflections. In this paper, a path identification method for UHF RFID using the measured power profile is presented. The method only requires a series of the received power measurement at the position of the target tag. By applying the steepest gradient method, we can optimize the parameters that defines the reflecting plane and eventually identifies the path direction. Together with theoretical development of the method, numerical example shows the validity of the method. © 2007 IEEE.

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Layer 3 diversity reception technology for Ku-Band mobile satellite communication systems

Nagase Fumiaki, Mitsugi Jin, Nakayama Masayoshi, Ueba Masazumi

IEICE Transactions on Communications E89-B ( 6 ) 1856 - 1861 2006.06

ISSN 0916-8516

We describe a layer 3 diversity reception scheme that enhances the transmission characteristics of Ku-band mobile satellite communication systems. This scheme can realize high-speed communication for vehicles that experience shadowing caused by terrestrial obstacles such as tunnels, buildings and bridges, especially for trains that frequently experience shadowing from the trolley wire structures. Layer 3 diversity was chosen for long distance diversity to prevent signal shadowing caused by terrestrial obstacles while minimizing the alterations of existing receivers. The technology enables high-speed communication under shadowing conditions in a running train environment. Copyright © 2006 The Institute of Electronics, Information and Communication Engineers.

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Anti-collision performance of Gen2 Air Protocol in random error communication link

Kawakita Yuusuke, Mitsugi Jin

68 - 71 2006

When a multitude of RFID tags are in the interrogating field, an anti-collision technology must be used. In literatures, the reading performance was mainly investigated on the error-free communication links between reader and tags. In the practical situations, particularly where a number of readers and other wireless devices share the same frequency band, the performance on the erroneous links would be significant interest. In this paper, we evaluated Gen2 Air Protocol paying attention to the anti-collision performance in random error communication link. As a result of simulation, two findings were obtained. Firstly, there is an appropriate number of slots depending on the number of tags. This number hardly changes even if a random error is incurred on the link. Secondly, the singulation speed might be significantly degraded particularly in erroneous links, if the optimal number of slots is not chosen. The findings can be interpreted such that the necessary link quality can be derived if the number of tags and permissible time are known a priori to the implementation. For instance, if 64 tags are required to be read in one second, it is necessary to ensure the link quality to be better than BER=10^-4 in random error environment. © 2005 IEEE.

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