Wireless Networks & Mobile Computing
be triggered, but the police and ambulance service will be informed via an emergency call
to a service provider. Buses, trucks, and trains are already transmitting maintenance and
logistic information to their home base, which helps to improve organization (fleet
management), and saves time and money.
b. Emergencies: An ambulance with a high-quality wireless connection to a hospital can
carry vital information about injured persons to the hospital from the scene of the
accident. All the necessary steps for this particular type of accident can be prepared and
specialists can be consulted for an early diagnosis. Wireless networks are the only means
of communication in the case of natural disasters such as hurricanes or earthquakes. In
the worst cases, only decentralized, wireless ad-hoc networks survive.
c. Business: Managers can use mobile computers say, critical presentations to major
customers. They can access the latest market share information. At a small recess, they
can revise the presentation to take advantage of this information. They can communicate
with the office about possible new offers and call meetings for discussing responds to the
new proposals. Therefore, mobile computers can leverage competitive advantages. A
travelling salesman today needs instant access to the company’s database: to ensure
that files on his or her laptop reflect the current situation, to enable the company to keep
track of all activities of their travelling employees, to keep databases consistent etc.
With wireless access, the laptop can be turned into a true mobile office, but efficient
and powerful synchronization mechanisms are needed to ensure data consistency.
d. Credit Card Verification: At Point of Sale (POS) terminals in shops and supermarkets,
when customers use credit cards for transactions, the intercommunication required
between the bank central computer and the POS terminal, in order to effect verification of
the card usage, can take place quickly and securely over cellular channels using a mobile
computer unit. This can speed up the transaction process and relieve congestion at the
e. Replacement of Wired Networks: wireless networks can also be used to replace wired
networks, e.g., remote sensors, for tradeshows, or in historic buildings. Due to
economic reasons, it is often impossible to wire remote sensors for weather forecasts,
earthquake detection, or to provide environmental information. Wireless connections,
e.g., via satellite, can help in this situation. Other examples for wireless networks are
computers, sensors, or information displays in historical buildings, where excess cabling
may destroy valuable walls or floors.
f. Infotainment: wireless networks can provide up-to-date information at any appropriate
location. The travel guide might tell you something about the history of a building
(knowing via GPS, contact to a local base station, or triangulation where you are)
downloading information about a concert in the building at the same evening via a local
wireless network. Another growing field of wireless network applications lies in
entertainment and games to enable, e.g., ad-hoc gaming networks as soon as people