 The complete opposite of
the typical radio engineer's
approach
Odaka: Although Sony promoted the
development of UWB (ultra-wideband)
from the end of the 1990s, I thought that
there were many difficult problems, such
as regulations differing between countries.
For example, if interference reducing
technologies are not included, then in
some countries the power must be
reduced, or in Japan, the device cannot be
used outdoors. Given that, we decided to
discover how far we could transmit if we
lowered the power output enough so that it
would clear the usage limits in any
country. What happened was that we took
UWB technology as the base, and made a
major shift in our thinking. As a result of
this study, we arrived at the idea of this
new type of coupler, and realized that we
could transfer data at high speed if we
limited the distance to under 3 cm.
Maekawa: Radio engineers have the
habit of wanting to transmit further and of
wanting to connect many devices
efficiently. Thus, to speak honestly, at the
start I thought the communication distance
of 3 cm was a limitation. However, when I
resigned myself to the distance and began
to consider what would happen when
distances were limited to 3 cm, I found that
there were actually many advantages.
This “limitation” will become, inversely, a
major sales point for this technology.
Odaka: Radio waves are, by their nature,
something that reach out to everyone
equally. This means that conventional
wireless systems cannot, due to their
nature, escape from the following three
problems: (1) the other party in the
communication must be identified, (2) data
must be encripted, (3) interference must
be suppressed. Thus complex connection settings cannot be avoided in wireless
systems. Inversely, however, if the radio
waves can only reach out to the very near
vicinity of the device, the system is freed
from that requirement and this becomes
an enormous advantage from the
standpoint of ease of use.
Maekawa: The strongest selling point
will be its simplicity.
Odaka: Although the latest wireless
systems have become easier to use, they
are still too difficult for older users.
Maekawa: Even for younger users,
although they would be able to use the
keyboard for the connection settings on a
PC, they would still have trouble with a
digital camera.
Odaka: We want to create a wireless
system that anyone can use pleasurably
anywhere. I think that it has become
possible to achieve this desire, which has
become the primary starting point for
wireless technology development, by
changing our original concept of wireless
communication. There was an interesting
episode related to this development. The
incorrect information that "Sony has
developed a wireless technology that can
only reach 3 meters." was released on the
Internet. This started a heated discussion
as to whether or not 3 meters was useful
or whether 3 meters was inadequate. But
when we made the correction to 3 cm, all
discussion simply stopped. With a
distance of 3 cm, this concept is really all
that is possible.
Transmission and reception
with natural motions
Odaka: This new coupler has the
characteristics that the gain increases
rapidly as the devices move close
together, and, inversely, the signal is
attenuated radically as they are moved
apart. This means that the switchover from
where the connection is on to where it is
off is extremely well-defined. It is not the
case the connection will be established
somewhere or other. The explicit user
action of bringing the devices together
connects directly with the device activity of
sending or receiving data. This makes it
possible to create an intuitive and easy to
understand interface.
Maekawa: The fact that the gain falls
rapidly when the devices are separated
can, of course, be seen as a disadvantage.
However, if we switch from the idea of
connecting to large numbers of devices to
a one-to-one connection concept, the
advantage of interference being less like to
occur becomes significant. For example, if
one is comes across a series of posters,
and only one is of interest, the usage
modality in which one acquires information
by holding one's cellular phone up just the
one of interest and downloads the music or
promotion video one likes is now possible
because of this new type of coupler.
Odaka: Since the concept is so clear, our
presentation at CES International was well
received. Since people from Japan are
used to and familiar with the "Touch & Go"
usage of the FeliCa* card in the public
transportation system, they quickly
understood that extremely high-speed data
transfers would be possible with the same
usage pattern. In contrast, since there are
USB systems that support fairly long
separation distances, the reaction of many
people from other countries was one of "Huh? Only 3 cm?". However, once the
concept is explained, most people
understood clearly and then reacted with "It's cool!".
Maekawa: I think that the transfer
technology itself is almost perfected. While
I can't mention a specific power consumption figure, I fully expect that the
power consumption per bit transferred will
be significantly lower than current wireless
LANs or Bluetooth. Although the transfer
rate could, technologically, be made quite
a bit faster, there are considerations from
the standpoint of the devices themselves.
In some sense, there is a pitcher throwing
a fastball called TransferJet, and a catcher
who must catch that ball (that is, the
various equipment and applications that
support TransferJet), and the current state
is that we must consider the combination
of those players. We must create many
ideal pitcher/catcher combinations.
Odaka: The most important thing is
determining which application runs when a
wireless connection is made. I hope to
create systems that will please users
through detailed discussions with the
people who develop end applications. I
hope that TransferJet will be able to
communicate openly, not just with Sony
products but with many devices from other
manufacturers as well, and we are now
working on preparations to make this
technology open to the public.
*: FeliCa is a registered trademark of Sony
Corporation.
*: FeliCa is a contactless IC card technology developed
by Sony Corporation. It is used widely for
tickets (electronic tickets) in public transportation,
for electronic payments, and personal
authentication. |
Vol.52