30-06-2012, 11:44 AM
The body as a communication medium
[attachment=26235]
ABSTRACT
Body sensor networks are currently not very intuitive and not
very reliable. In the last couple of years body coupled communications
has been rediscovered after a period of disinterest.
In this paper an overview of recent research into body coupled
communications is given. This research into body coupled communications
shows that body sensor networks are not the only
ubiquitous computing application where it could be useful. From
recent research a number of guidelines for using body coupled
communications are developed to help future research in ubiquitous
computing.
INTRODUCTION
Ubiquitous computing (UC) has come a long way since its inception
by Marc Weiser. Making computers intuitively blend into
the environment has been a major area of research during the past
twenty years. Many advances have been made in ubiquitous computing.
One of them is the recent development of body sensor
networks, but currently these networks are neither intuitive nor
do they blend seamlessly into environment. Body coupled communications
(BCC) is a new technology that might make body
sensor networks more intuitive and more seamless.
Operating principles of Body coupled communications
Body coupled communications is a physical layer technology where
the signals travels "on" and "in" the body instead of through and
o the body as with radio. This can be seen in figure 1 citekaist:low.
The electric field of the body is subtly modified so that a message
can be sent and received. This gives a workable channel for
communications that "sticks" to the body. The receiver and the
transmitter are connected to this channel leading to an ethernet
like network on the body [1] [2].
Current problems with communication
in body sensor networks
While wireless sensor networks are gradually becoming mainstream,
the smaller related body sensor networks are still in their
infancy. Body sensor networks consists of number of intercommunicating
sensors that can be worn and that monitor the body.
These devices communicate to each other and possibly send data
to an o body location for further processing. While related to
wireless sensor networks the challenges are di erent. Body sensor
networks have to deal with more dynamic environment than
wireless sensor nodes because humans rarely sit still. This causes
problems with the communication between the nodes with the radio
techniques currently used. To overcome problems with transmission
such as interference and disconnects the power of the
transmission is increased [3]. This allows the signal to be received
from a greater distance, leading to privacy concerns. Interference
is a major problem with radio based technologies because
most radio based techniques use frequencies that are near
to each other and that are also used for other purposes like telephony
[3] [4]. Because the signal strength is increased to minimize
interference the power usage increases leading to batteries
running out of power sooner.
Previous work
Body coupled communications was discovered in the middle of
the nineties. At MIT Zimmerman [5] discovered body coupled
communications by accident while doing human interface
research on position sensors. Simultaneously at the Sony Labs a
similar technology was developed that resulted in the wearable
key prototype [6]. These discoveries led to an initial media
frenzy. But soon afterwards interest was lost in body coupled
communications because of what was then thought were fundamental
limitations of the technology (Zimmerman thesis mistakenly
stated that the technology had fundamental limit of 852
Kb/s). During the initial stages there was also research done at
powering devices via the body. But this did not lead to much [2].
Power usage & data transmission speed
As seen in table 3, practical body sensor networks need to have a
fair amount bandwidth available. But having a fast network that
consumes a lot of power is undesirable for a human area network
since the network is worn, and it is inconvenient if the nodes need
constant recharging. The transmission speed of body coupled networks
was for a long time a significant problem, because it was
thought that there was a theoretical maximum of 852 Kbit/s [5].
CONCLUSION
In the paper it is shown that body coupled communications is
used in more ways than just a drop in replacement for radio based
techniques in body sensor networks. The applications range from
very simple and low cost implementations to very advanced communications
and just about everything in between. Body coupled
techniques opens the door for innovative new ubiquitous computing
applications like authentication by touch and low power body
sensor networks.
[attachment=26235]
ABSTRACT
Body sensor networks are currently not very intuitive and not
very reliable. In the last couple of years body coupled communications
has been rediscovered after a period of disinterest.
In this paper an overview of recent research into body coupled
communications is given. This research into body coupled communications
shows that body sensor networks are not the only
ubiquitous computing application where it could be useful. From
recent research a number of guidelines for using body coupled
communications are developed to help future research in ubiquitous
computing.
INTRODUCTION
Ubiquitous computing (UC) has come a long way since its inception
by Marc Weiser. Making computers intuitively blend into
the environment has been a major area of research during the past
twenty years. Many advances have been made in ubiquitous computing.
One of them is the recent development of body sensor
networks, but currently these networks are neither intuitive nor
do they blend seamlessly into environment. Body coupled communications
(BCC) is a new technology that might make body
sensor networks more intuitive and more seamless.
Operating principles of Body coupled communications
Body coupled communications is a physical layer technology where
the signals travels "on" and "in" the body instead of through and
o the body as with radio. This can be seen in figure 1 citekaist:low.
The electric field of the body is subtly modified so that a message
can be sent and received. This gives a workable channel for
communications that "sticks" to the body. The receiver and the
transmitter are connected to this channel leading to an ethernet
like network on the body [1] [2].
Current problems with communication
in body sensor networks
While wireless sensor networks are gradually becoming mainstream,
the smaller related body sensor networks are still in their
infancy. Body sensor networks consists of number of intercommunicating
sensors that can be worn and that monitor the body.
These devices communicate to each other and possibly send data
to an o body location for further processing. While related to
wireless sensor networks the challenges are di erent. Body sensor
networks have to deal with more dynamic environment than
wireless sensor nodes because humans rarely sit still. This causes
problems with the communication between the nodes with the radio
techniques currently used. To overcome problems with transmission
such as interference and disconnects the power of the
transmission is increased [3]. This allows the signal to be received
from a greater distance, leading to privacy concerns. Interference
is a major problem with radio based technologies because
most radio based techniques use frequencies that are near
to each other and that are also used for other purposes like telephony
[3] [4]. Because the signal strength is increased to minimize
interference the power usage increases leading to batteries
running out of power sooner.
Previous work
Body coupled communications was discovered in the middle of
the nineties. At MIT Zimmerman [5] discovered body coupled
communications by accident while doing human interface
research on position sensors. Simultaneously at the Sony Labs a
similar technology was developed that resulted in the wearable
key prototype [6]. These discoveries led to an initial media
frenzy. But soon afterwards interest was lost in body coupled
communications because of what was then thought were fundamental
limitations of the technology (Zimmerman thesis mistakenly
stated that the technology had fundamental limit of 852
Kb/s). During the initial stages there was also research done at
powering devices via the body. But this did not lead to much [2].
Power usage & data transmission speed
As seen in table 3, practical body sensor networks need to have a
fair amount bandwidth available. But having a fast network that
consumes a lot of power is undesirable for a human area network
since the network is worn, and it is inconvenient if the nodes need
constant recharging. The transmission speed of body coupled networks
was for a long time a significant problem, because it was
thought that there was a theoretical maximum of 852 Kbit/s [5].
CONCLUSION
In the paper it is shown that body coupled communications is
used in more ways than just a drop in replacement for radio based
techniques in body sensor networks. The applications range from
very simple and low cost implementations to very advanced communications
and just about everything in between. Body coupled
techniques opens the door for innovative new ubiquitous computing
applications like authentication by touch and low power body
sensor networks.