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interface so fewer components are required, for example those for antenna
matching. Some even have an integrated antenna, either as primary radiator or
as a backup if an external antenna is damaged or becomes disconnected.
The more components that a printed circuit board has to carry, the more complex
and expensive it becomes. Using a multiradio solution contributes to simplicity
and will not only enable smaller boards to be used but may facilitate using boards
with fewer layers, which can result in considerable cost savings.
One implementation - several radio options for the user
The overall cost savings from using multiradio solutions make it economical to
implement this design strategy across a product range, even when different
products will eventually use only one of the available wireless protocols. For
example, you may want to offer Bluetooth or Wi-Fi versions of a product, rather
than one that’s designed for both.
The approach is particularly useful with a range of products that use a common
architecture, and perhaps a common main printed circuit board for all the
variants. Even if one of the products in the range only uses one of the wireless
technologies, the implementation and maintenance is minimized for the entire
product range.
External technology discovery and proximity detection
There is often a requirement for two wireless-enabled devices to connect
automatically when they come within range of each other. Sometimes one radio
technology is used for device service discovery and another for data exchange.
One of the wireless technologies frequently implemented in multiradio solutions
is Bluetooth low energy. With its unique radio service discovery, Bluetooth low
energy becomes particularly useful in multiradio implementations. The protocol
can be used to detect a user or device when the signal close to another device,
effectively acting as a proximity beacon. Once detected, a second radio technology
can be used for the data exchange if higher bandwidth is required.
For example, in a retail point-of-sale environment, Bluetooth low energy signals
may advertise the presence of the nearest receipt printer to a hand-held payment
terminal. The connection set up
and data transfer could then take place over
Classic Bluetooth or Wi-Fi.
In this use case only one of the radio technologies is being used at a time.
Wireless coexistence
Some systems require wireless
technologies to be operating
concurrently. There is potential signal
interference in these circumstances,
resulting in higher latency because
of the need to use packet traffic
arbitration to avoid simultaneous data
transmission and reception, or even
data loss due from receiver input
saturation.
These potential side effects are
clearly unacceptable in mission-critical
industrial and medical applications so
it’s important to optimize coexistence
of the various wireless technologies to
ensure interference-free operation.
Using multiple single-technology radios
means that longer development time is
needed todeal withwith the coexistence
issue, adding to cost and extending
time-to-market for the end product.
In a stand-alone multiradio device,
coexistence is handled within the
multiradio chip, eliminating these
challenges.
Minimizing type-approval
effort
Implementing several single-radio
solutions in a product requires extra
regulatory testing. Even if a single
wireless module has obtained modular
regulatory
approval,
additional
testing and reporting will be required
when integrating additional radio
modules into the device. This once
again extends time-to-market, adds
development cost, adds test facility
cost, and increases technical risks.
With a stand-alone multiradio module
these problems are avoided.
Multiradio solutions - ideal
for gateways
A wireless gateway is a networking
device that routes packets from
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