May 13, 2002 (TOKYO) -- A new "au" handset by KDDI Corp., which sports global
positioning system (GPS) technology, could turn out to be the savior of Japan's market for
mobile phones.
The phone market, which has recently been rapidly losing its momentum, just might be
given new life by the advent of more GPS-equipped handsets.
The au C3003P handset (photo) -- manufactured by Matsushita Communication Industrial
Co., Ltd. (MCI) -- was released in March and looks as if it is going to turn out to be a very
big hit.
It now seems likely that NTT DoCoMo Inc., having seen how popular au's phone is
becoming with users, will follow suit and start marketing its own new GPS handsets
sometime soon.
The new GPS-equipped phones allow users to look at a map which shows their current
location and, if the user inputs the name of the place they want to get to, will select the
most appropriate route and guide them to their destination.
When earlier models of these types of position-locating GPS phones first hit the market
back in December 2001 the reaction from users was rather cool, but the C3003P phone has
changed that and is turning out to be a huge hit thanks mostly to the fact that it has a
special built-in magnetic sensor which improves the GPS navigation functions per se.
Navigating with Mobile Phones
There are a number of mobile phone services that allow users to see where they are on a
map -- NTT DoCoMo's "i-area" for example -- which have been around for sometime.
However, rather than using GPS satellites, these earlier phones rely only on signals from
the phone network's antenna base stations located in the surrounding area to calculate
where the user is. For that reason, they can only give a rough approximation of the user's
whereabouts: they can be wrong by up to 500m in cities and up to several kilometers in
suburban areas.
Available since the end of 2001, phones incorporating GPS technology are able to be much
more accurate, with the user's location shown as a specific point on a map. If there are no
tall structures in the vicinity GPS phones can be accurate to just a few meters, and even if
the user is inside or somewhere surrounded by tall buildings the phone will still be able to
pinpoint the location to within several tens of meters. Thus, GPS handsets have made it
possible for pedestrians to benefit from the same type of navigation services as those
enjoyed by car drivers.
Navigation has always been a very popular response in market surveys that ask users
what they would like to use their phones for. The growing popularity of the au C3003P
handset confirms that this is something many users have been waiting for. The new phone
is enjoying brisk sales, and many users are reportedly defecting from services offered by
competitors NTT DoCoMo and J-Phone Co., Ltd.
Common Chips for CDMA and GPS
Although au's new GPS phone has a built-in receiver for picking up GPS satellite signals,
its size and weight are almost the same as ordinary phone models. This is because the
wireless communications protocol that au phones employ is code division multiple access
(CDMA) and the part of the CDMA chipset made by Qualcomm Inc. that the new phone
uses to process incoming CDMA signals can also handle GPS signals.
And it isn't just simply that the chips are shared. In fact, when the phone is working out
its user's location, it can employ both GPS and CDMA signals -- the phone shares common
signals. Reception of GPS signals transmitted from satellites in space can be disrupted in
areas where there are lots of tall buildings or when the user is indoors. However, the au
phone uses CDMA signals to supplement GPS by helping to calculate where the user is
whenever GPS reception is difficult. Therefore, as long as users are somewhere in the
service area of the CDMA network, they are able to use their phones if GPS signals are
blocked.
Although it handles GPS signals, the chipset does not actually process all the GPS data
itself within the phone handset. Special servers that are capable of processing the GPS
data carry out that task. This system, which is called "wireless assisted GPS," was
originally developed by SnapTrack Inc., a company that was purchased by Qualcomm in
March 2001. Of the three main tasks involved in processing GPS signals: (1) detecting
satellites, (2) receiving signals, and (3) working out longitude/latitude. The phone itself
only performs (2). The other jobs, (1) and (3), are left to the system's servers.
Thanks to this setup, task (1) only takes between 17 and 19 seconds. That compares with
the minutes, or even tens of minutes, that stand-alone GPS devices require. Also, leaving
(3) -- the actual work of calculating the user's location -- to the servers enables the phone
to save power, which means that it can use the same type of batteries as those employed
in ordinary handsets without any noticeable deterioration in battery longevity.
Success of au's GPS Phone Helped by Magnetic Sensor
The C3003P GPS phone employs such an advanced chipset and looks well on the way to
becoming a hit product, but when GPS handsets first appeared in December 2001 user
demand didn't match original expectations. It was then thought that more than 800,000
phones would be on the market by the end of March 2002, but in fact only 654,700 units
were sold by that date. The reason, according to a phone retailer, was that users were not
really sure what advantages GPS held for them.
The C3003P handset, which was launched at the end of March, differs from its GPS
predecessors in that it has a built-in sensor for detecting the direction of the Earth's
magnetic field and is compatible with the NAVITIME service from Navitime Japan Co., Ltd.
When the GPS map is displayed on the phone's screen to show the user's location, the
direction in which the phone is being held (i.e. the direction the user is facing) is always
displayed the right way up (i.e. at the top of the screen). This makes it easier for users to
get their bearings right and to know which direction they should walk in next to get to a
particular place.
Older GPS phone models are also equipped with navigation features, but because the top
of the screen is always "north" users sometimes get confused. This is because unless they
carry a compass around with them or watch the Sun's movement across the sky, they
often don't know which direction they are facing in anyway and, at a crossroads, for
example, the phone's map becomes useless.
Multi-Layering Allows for Smaller Chip Sizes
The C3003P handset incorporates an AM-45 fluxgate-type magnetic sensor (see photo)
developed by AP One Systems KK. The sensor itself and all its accompanying circuitry are
integrated into a single 9-layer chip package that measures just 8.5mm x 8.5mm x
1.5mm. The chips cost somewhere between 400 and 450 yen each. Inside the handset,
the chip has to be carefully positioned in such a way that it is not affected by the
magnetic field of the phone's own speaker. The phone's casing also has to be made of
completely non-magnetic resins.
Other types of magnetic sensors are appearing. The MI-IC-2DL magneto impedance sensor
developed by Aichi Steel Corp. is attracting lots of attention because even though it is
smaller than the AM-45 sensor, it is sensitive to just 0.1mG (milli Gaus). Sample
shipments have already begun and mass production is scheduled to start in October. The
price is expected to be between 300 and 400 yen per sensor.
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