dynamically select either the Bluetooth
radio or the Wi-Fi radio based on the
need for faster transmission, or not.
If you follow the wireless field at
all, you know that there are many
other wireless standards and methods
out there. Most of the short-range
technologies are competitive with
one another in some way. Yet even
with the competition, Bluetooth has
carved out a healthy niche, if you can
call billions of units sold a niche.
Bluetooth had a head start on most
of the other technologies and that is
partially the reason Bluetooth is so
well entrenched. While Bluetooth
applications may overlap a bit with
Wi-Fi and UWB, the SIG was smart
to adopt these technologies to support Bluetooth in some applications.
So you can almost write off Wi-Fi and
UWB as competition. That leaves
ZigBee as the only clear competitor.
ZigBee is that technology
developed around the IEEE 802.15.4
standard that targets industrial
control, building monitoring and
control, remote meter reading, and
other applications where sensor
outputs are observed and used to
initiate controls or record the data.
It uses very low power so a ZigBee
transceiver can operate for months
or even years on a coin battery.
ZigBee’s big claim to fame is its
ability to form mesh networks among
hundreds of radio nodes. While
Bluetooth has some limited networking capability, it was not designed for
mesh networks. So, while the two
technologies may butt heads in a few
applications, for the most part each
has its own sphere of uses.
The only other short-range
technology that may come close to
Bluetooth in volume is ISM band
radios that operate in the 315, 433,
and 915 MHz range. These are used
in garage door openers, remote
keyless entry devices for vehicles,
tire pressure monitoring, remote
thermometers, and toys. These
devices are usually much simpler
so do not need the sophisticated
protocol of Bluetooth.
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As I mentioned earlier, the
leading Bluetooth chip company is
Cambridge Silicon Radio (CSR). They
were one of the first vendors and
they still maintain a wide lead over
the others. Other Bluetooth chip
companies are Broadcom and Texas
Instruments. Figure 1 shows CSR’s
latest transceiver chip which
incorporates the latest Bluetooth EDR
radio, a low power transceiver, a GPS
satellite navigation receiver, and a
standard FM radio all in one. It is
expected that this chip will save lots
of space and power when built into
cell phones. NV