Page 43 - DCAP311_DCAP607_WIRELESS_NETWORKS

Unit 2: Wireless System Architecture

2.3.1. Digital Signals Notes

Digital signals are quite different from the analog signals because they are based on the numeric
methods. It is defined as the types of signal which are used to represent the quantities which use
the numeric method to deliver the information are called as the digital signals. Basically they are
in discrete form. Sometimes they are said to be more reliable in the field of computer technology
because they are used to transfer data. With the presence of continuous waves in the digital
signals they really helpful in avoiding the rise a fall like in analog signals.

2.3.2. Analog Signals

There are different forms of signals one of them is the analog signal. It is defined as the type of
signal that are used to express the quantities that are based on the variability of time and different
type of time based processes such as electrical, some of mechanical and hydraulic etc are called
as the analog signals. Different type of minute fluctuations are used fro the sake of process by
analog signals. They also use the same method to pass on the information between different
places. Wires are used for the processes of analog signals.

Self-Assessment

State whether the following statements are true or false
9. Network “is a function that conveys information about the behavior or attributes of some
phenomenon”
10. Application Layer is the OSI layer closest to the end user, which means that both the OSI
application layer and the user interact directly with the software application
11. The Data Link Layer establishes context between Application Layer entities
12. The operation of setting up a session between two processes is called “Binding”.
13. The Transport Layer provides transparent transfer of data between end users, providing
reliable data transfer services to the upper layers.
14. The Network Layer provides the functional and procedural means of transferring variable
length data sequences from a source host on one network to a destination host on a different
network
15. Presentation Layer provides the functional and procedural means to transfer data between
network entities and to detect and possibly correct errors that may occur in the Physical
Layer.
16. Open Systems Interconnection model (OSI model) is a product of the Open Systems
Interconnection effort at the International Organization for Standardization.

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Case Study Securing Wireless Networks

How do wireless networks work?
As the name suggests, wireless networks, sometimes called WiFi, allow you to connect
to the internet without relying on wires. If your home, office, airport, or even local coffee
shop has a wireless connection, you can access the network from anywhere that is within
that wireless area.
Wireless networks rely on radio waves rather than wires to connect computers to the
internet. A transmitter, known as a wireless access point or gateway, is wired into an
internet connection. This provides a "hotspot" that transmits the connectivity over radio
Contd...

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