Responsible for this page: J Jacob Wikner , jacob.wikner@liu.se
Page last update: 2012-08-27

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Transceivers for body-area network communication

- funded by CENIIT (Main sponsor)

- funded by VINNOVA (Prototype sponsor)

Background

- project background and industrial motive

The social media, the usage of smart mobile phones and wider coverage of mobile networks is shrinking down our world in terms of connecting people. The six-handshakes-away "theory" becomes more and more viable.

Since recently, so called near-field communication (NFC) is finding its way into the smart phones and a new infrastructure with respect to communication between humans and devices is being built up. The NFC typically relies on the widely used RFID technique. The RFID technique does indeed come with different operation principles, but the most dominating ones are inductive and microwave-based coupling techniques. The inductive principles uses a coil to generate/absorb a magnetic field. In this way, data can be transmitted/received between two or more devices. The technique is "old" in the sense that is is found in securtiy systems (entrance systems, shop lifting, etc.) and logistics (package tracking, etc.). Recently, however, the NFC is extending this concept in other applications, such as flight check-in, and more.

The suggested techniques, however, are typically limited in two ways: the transmission speed is relatively low (well...) and operation relies on the need to take your smart phone out of your pocket and keep close to a transceiver. The applications are still oriented towards the transfer of your ID, a short key of some kind, or similar.

Our project has a slightly different scope with focus on the transceivers of such communication scenarios; first of all, we are aiming for higher data rates and secondly we are looking to use the human body as a communication channel. This combination of NFC with body area network (BAN) is going to increase the number of applications, but on the other hand, it is also going to put tougher requirements on the transceiver specifications.

A twist in this scenario is that the body channel does not offer an inductive interface, instead it is capacitive.

Vision and industrial motive

The strongest motivation which would be given in favour of capacitive/inductive coupling transceivers is; cell-based communication systems, which forms the core of today's mobile/wireless communications, are no longer able to meet the requirements of increased level of information/multimedia sharing among the users of smart devices because of the limited number of frequency carriers and almost the completion of the frequency allocation table. That is why big companies, like Apple and Google, are also looking forward towards these transceiver architectures as viable means of next-generation touch-and-go communication.

In a world, where it is imagined that our ambiance would also be soon intelligent along with a scenario where each person in the world would be wearing five to ten cheap sensor nodes able to intelligently communicate with each other or with the personal CPU, it will not be possible to assign or allocate different carrier frequencies for every device or individual. So the only viable solution to make this a realizable dream is; we develop transceivers based on capacitive/inductive coupling. The applications which could be built up around the basic theme of capacitive/inductive transceivers could have many forms, a few of them just listed below;

  • Low power Escalators which turn on inductively/capacitively when the user comes in its close vicinity
  • New door (un)locking systems which use inductive/capacitive coupling-based transceivers
  • Inductive/capacitively coupled photocopier, fax, printers
  • Electronic money transfer (a mass phenomenon)
  • Human body channel using inductive/capacitive coupling-based transceivers for communication between wearable sensors
  • Capacitively-coupled touch panels with intelligent lighting layouts for easily switching on the lights,
  • IP-based smart dust motes using capacitive/inductive coupling mechanism for information transfer
  • Mobile-to-Mobile or Machine-to-Machine transfer of information
  • Intelligent gaming consoles using capacitive/inductive coupling based transceivers
  • Multimedia transfer (high fidelity sound and high definition video)

Any of these suggested topics (and some being already established using other means of communication), we believe, will be strong drivers for the project and attractive to industry and the research community.

Research group

- a description of the research group where the project is conducted

The research on body-area networks, as suggested in this project, is being performed at the Electronics Systems group, at the Department of Electrical Engineering (ISY), Linköping University.

Researchers

  • Dr. J Jacob Wikner, Associate professor
  • Muhammad Irfan Kazim, Ph.D. student

The main applicant, Dr. J Jacob Wikner, is currently conducting research on different types of mixed-signal integrated circuits (high-speed, low-power) and has several publications in the area of D/A and A/D converters for communication applications. He has a 10-year industrial experience where for example D/A converters for WCDMA, A/VDSL, WLAN and AFEs for video applications have been developed in process nodes down to below 40 nm. The mixed-signal integrated circuits have been developed to be placed into large systems on chip with focus on low-voltage technologies.

Picture of (parts of) the project team.
From left to right: Irfan Kazim, Shehryar Khan, Prateek Sharma, J Jacob Wikner, Ghafoor Shah, Muhammad Umer Khalid, Amit Mittal, and Anup Kini.

The exjob team

The project is supported by our team of thesis students. Some of them (including alumni) is found below:

  • Erik Staflin
  • Oscar Nilsson
  • Dilip Kumar Vajravelu
  • Bibin Babu
  • Kiran Kariyannavar
  • Abdullah Korishe
  • Md Hasan Maruf
  • Amit Mittal
  • Prateek Sharma
  • Rahman Ali
  • Ghafoor Shah, Internship
  • Shehryar Khan, Internship
  • Mohammad Umer Khalid, Internship

Hardware aspects

The transceiver architecture must permit low-power operation and it should also be possible to integrate in the smart phones and preferrably the systems-on-chips found in the terminals.

The body is attenuating the signal quite heavily and the transfer characteristic is also dependent on the movements and position, body condition, etc. Typically, the transmitted signal can be in the Volts range whereas the received signal is in the milivolts range (and below). This implies a very sensitive receiver.

The hardware must also be able to characterize the channel in order to adaptively adjust for, e.g., power levels to further lower the power consumption and/or increase data rate. The position of the body, the distance between transmitter and receiver will influence the channel dramatically.

In the figure below, we have sketched the capacitive coupling scenario. Two BAN transceivers (in this example) will now communicate with eachother utilizing the capacitive field through and around the body. The coupling through air is weak and the body provides better conduction.

Example of a capacitive coupling scenario with the human body acting as a communication channel.

A photo of our transceiver is outlined in the figure below (notice the default setup to illustrate the testbench). The modem is currently implemented in FPGA, the transceiver on a sparse slave PCB, and capacitive pads are on PCBs without passivation. The transceiver can also be butted to the FPGA to get power supply from it. Further on, the transceiver has a microcontroller for autoadjustment of signal levels, filtering response, etc., on the transceiver board.

Example of communication through your body via the hands using half duplex.

Long-term vision

- long term vision of the project

The long-term vision of this project is to investigate and open for new communication scenarios where the activation of the user, his/her social interaction, is taken into account. We step away from the traditional file-transfer protocol mode. Communication will be more emotionally controlled and we use other types of channels to perform that communication.

Billions of devices directly or indirectly connected to the internet are now circulating on our globe. Some claim there are more mobile phones than tooth brushes out there. Somehow, this has to be handled. There is a massive infrastructure and a massive amount of data that needs to processed.

There are additional biological aspects, in the same way as we can communicate through our body, we can communicate with our body. Already today, we see plenty of applications where we measure heart beats (pulse), skin conductivity, EEG, ECG, etc. So ... what about revisiting the old ideas of measuring the body itself? Can we make predictions of the state of the body? Can a heart attack be predicted? Can we warn if a lumbago is about to happen? Or can we log and feed back to the person about his body movement patterns such that long term "wear and tear injuries" can be avoided.

Industrial relevance

- description of connections to industry and other CENIIT projects

At this moment we are cooperating with Ericsson, one of the world's largest actor within the filed of telecommunication. Additionally, the project has become a subpartner of a VINNOVA-funded framework program with Acreo as main recipient of funding. In the consortia we cooperate with the ITN in Norrköping. As additional industrial relevance we also emphasize on large players like the Disney corporation: where similar ideas are highlighted.

List of publications

- list of publications related to the project

  • P. Harikumar, Mohammad Irfan Kazim, and JJ Wikner, Pending contribution to the NorChip Conference, November 2012, Copenhagen, Denmark
  • S. Arslan, G. Shah, "A Flexible in-Field Test Controller", IEEE International Multitopic Conference 2011, pp.71-75, 22=24 Dec. 2011
  • S. Roy; Md. M.K. Nipun; JJ Wikner; "Ultra-low power FIR filter using STSC-CVL logic", in 2011 IEEE International Conference on IC Design and Technology, ISBN no. 978-1-4244-9020-2, Kaohsiung, Taiwan.
  • D. Chhetri, V.N. Manyam, and JJ Wikner, "Event-driven clockless 8-bit DM ADC for smartdust applications," in Proc. 19th IFIP/IEEE Int. Conf. Very Large Scale Integration (VLSI-SoC), Hong Kong, October 2011.
  • D. Chhetri, V.N. Manyam, and JJ Wikner, "An Event-Driven 8-Bit ADC with a Segmented Resistor-String DAC," in Proc. European Conf. Circuit Theory Design, Linköping, August 2011.
  • C. Svensson and JJ Wikner, "Power consumption of analog circuits: a tutorial," Analog Integrated Circuits and Signal Processing, pp. 1-14, 2010

External references

- list of external references

  • Zimmerman T G. Personal Area Networks (PAN): Near-Field Intra-Body Communication[D]. MIT Media Lab, 1995.
  • Zimmerman T G. Personal area networks: near-field intrabody communication[J]. IBM Systems Journal. 1996, 35(3-4): 609-617. (Pubitemid 126593292)
  • Li Yin-lin; Huang Zhong-hua; , "Modeling of Body Area Network in medical healthcare applications," IT in Medicine & Education, 2009. ITIME '09. IEEE International Symposium on , vol.1, no., pp.100-104, 14-16 Aug. 2009
  • Wegmüller, M.S. "Intra-Body Communication for Biomedical Sensor Networks", ETH Zurich Doctor dissertation, Switzerland, 2007.
  • Coronel P, Schott W, Schwieger K, Zimmermann E, Zasowski T, Maass H, Oppermann I, Ran M, Chevillat P. Wireless body area and sensor networks. Wireless World Research Forum (WWRF) Briefings 2004.
  • Wegmueller, M.S.; Kuhn, A.; Froehlich, J.; Oberle, M.; Felber, N.; Kuster, N.; Fichtner, W.; , "An Attempt to Model the Human Body as a Communication Channel," Biomedical Engineering, IEEE Transactions on , vol.54, no.10, pp.1851-1857, Oct. 2007

Fun and trivia

Contact

Authors: J Jacob Wikner and Muhammad Irfan Kazim.

Please navigate to the ES' home page for more contact information.

Please also drop by on our mixed-signal ic design page on facebook for more updates.