Wi-Fi enabled devices. Your
smartphone connects to the Internet
via your cellular provider. Then, any
Wi-Fi device — like a laptop, tablet, or
other smartphone — can link to your
smartphone. Your phone serves as
the wireless router. You will need to
determine if your phone will do this
and what restrictions (if any) your
#9 — White space may use
White space is the term used to refer
to the unused TV channels around
the country. The goal is to use these
vacant channels as ways for homes
and businesses to connect to the
Internet as an option to other high
speed broadband services from cable
TV or phone company DSL. The
location of these blank channels
varies by locale, so a method has
been developed to locate each
vacant channel. A database of these
channels and other wireless devices
(like wireless microphones) has been
established, and any white space data
radio has to access the database to
find a vacant channel that will be the
least likely to cause interference.
Most of these channels are UHF
TV channels 20 to 31 in the 470 to
710 MHz range. Each channel is
6 MHz wide so can carry high data
rates with the right modulation. A
special version of Wi-Fi — which
many refer to as Super Wi-Fi — is
based on the IEEE 802.11af standard.
It uses OFDM and up to 64QAM to
provide data rates from a few Mb/s
to 20 Mb/s or so, depending on
range and noise conditions. The
range at these UHF bands greatly
exceeds the range of most 2. 4 and 5
GHz versions of Wi-Fi, which is 100
meters at best and usually less. White
space range can be up to several
miles under the right conditions.
White space radios and services
are just now becoming available.
Another IEEE standard called 802.22
is competing with the Wi-Fi version.
74 October 2013
; FIGURE 1.
Texas Instruments’ SimpleLink Wi-Fi CC3000
BoosterPack kit was designed to help engineers design
new M2M and Io T applications. It speeds and simplifies
Wi-Fi Internet connectivity development and uses TI’s
MSP430 or TivaC series of MCUs.