1 Prolonged use of mobile phones
can have health implications. Give
examples of these.
1.1 The reviewers said: “The substantial body of evidence
highlighted in this report suggests that mobile phone use may
be linked with a range of important health problems. These
include, but are not limited to, brain tumours and the
evidence has serious implications for public health. Although
further research is needed, it makes sense to err on the side
of caution in the meantime.”
1.2 How they do it
1.2.1 Cell phones emit radiofrequency energy, a form of non-ionizing electromagnetic radiation, which can
be absorbed by tissues closest to where the phone is held. The amount of radiofrequency energy a
cell phone user is exposed to depends on the technology of the phone, the distance between the
phone’s antenna and the user, the extent and type of use, and the user’s distance from cell phone
towers. Studies thus far have not shown a consistent link between cell phone use and cancers of the
brain, nerves, or other tissues of the head or neck. More research is needed because cell phone
technology and how people use cell phones have been changing rapidly.
2 Bluetooth is used in the Easy Walk
service. What are the limitations of
2.1 1. Speed. Bluetooth is not designed for
high-speed data transfers.
2.2 2. Range. The range of communications is often
limited to a few feet (I've seen as few as 2 and as
many as 30).
2.3 3. Compatibility. Some devices do not have
profiles compatible with the devices you want to
3 What is GPS technology? How does it work?
3.1 The Global Positioning System (GPS) is a space-based satellite
navigation system that provides location and time information in all
weather conditions, anywhere on or near the Earth where there is
an unobstructed line of sight to four or more GPS satellites.
3.2 Global Positioning System satellites transmit
signals to equipment on the ground.