2. In general we will define what a mobile network is and how this type
of network aims to provide connectivity for users. We will also discuss
how a mobile network differs from other networks, such as wireless
networks.
Wireless technologies which provide communications between
devices, for example, a laptop maybe connected wirelessly to a
printer via radio using the Bluetooth standard.
3. What is a Mobile Network?
Many people believe that when you say 'mobile network' you are
referring to a wireless network. In actuality, a mobile network and a
wireless network are two different types of networks.
A mobile network can be defined as a communications network that is
spread out over an immense land area around the world, connected
wirelessly by transceivers at fixed locations that are known as cell
sites or base stations.
Transceivers :- communicate wirelessly based on the old principle of
radio signals. Radio signals are electromagnetic radiation that
includes light and infrared waves. These signals are considered to be
transverse waves in that they have a frequency and a wavelength.
4. Continued..
Wavelengths :- Are measured in the distance between the peaks of
sequential waves and the frequency is the number of cycles per
second. To calculate the speed of a transverse wave, you multiply the
wavelength and the frequency. Figure 1 below depicts the direction of
travel of a radio signal, the wavelength and the amplitude.
5. How Mobile and Other Networks Differ
As stated previously, many people think that a mobile network and a wireless
network are one in the same. While they perform similar functions, they are
completely different networks.
A mobile network commonly is described as a physical device that can be taken
anywhere as outlined in Figure.
It is composed of a battery to provide power and must have some type of mobile
network connectivity in order for the device to operate in order to send and receive
data without having to attach the device to a hardware base.
6. Continued…
In the case of wireless, this does not mean a physical device. Wireless
mean having access to a wireless network such as a local area network
(LAN), wide area network (WAN), or a 4G/3G cellular network.
In instances like this, you take what used to connect through a router and
cable and make that connection wireless.
These types of networks still require some type of physical hardware within
close proximity to have a physical connection to a power supply and a
router or network node in order to communicate.
A wireless network provides a fixed or portable endpoint to gain access to a
distributed network.
A mobile network, on the other hand, provides access to the distributed
networks, through a portable device, that allows you to travel anywhere,
as long as there is sufficient coverage.
7. Mobile networking devices
Mobile IT devices can use almost any wired and wireless networking
technologies, as long as they are enabled to do so, either by in-built capability or
via a network adapter.
What are the different types of mobile network?
Several different technologies exist that support mobile networking, including:
using the global system for mobile communications (GSM), general packet radio
service (GPRS) and third-generation (3G) and fourth-generation (4G) services
offered by mobile networks
cable connection to 'wired' local area networks (LANs) - Ethernet is the most
popular wired LAN technology
secure 'wireless LANs' within office buildings or public 'hot spots' such as internet
cafes - wireless fidelity (Wi-Fi) is the most popular wireless LAN technology
Bluetooth or infra-red connection to another mobile device that offers one or
more of the above connection capabilities
extranets that can be accessed remotely, allowing mobile staff to use limited
areas of your business' website and data
use of smartphones to facilitate instant email access
8. Applications of mobile networking
Sometimes you don't need networking capability on the move. It might
be sufficient to download and upload the information required at the
start and end of the day from the office computer system.
However, real-time communication with the office can be important in
delivering business benefits, such as efficient use of staff time,
improved customer service and a greater range of products and services
delivered. Examples include:
making presentations to customers, and being able to download product
information to their network during the visit
quotations and interactive order processing
checking stock levels via the office network
interacting with colleagues while travelling - sending and receiving
emails, collaborating on responses to tenders, delivering trip reports in a
timely manner
9. Medium Access Protocol
The media access control (MAC) data transmission protocol sub-layer,
also known as the Medium Access Control, is a sub layer of Data link
layer specified in the seven layer OSI model (layer 2).
The hardware that implements the MAC is referred to as Medium
Access Controller.
Several medium access control (MAC) algorithms are specifically
adapted to the wireless domain.
Medium access control comprises all mechanisms that regulate user
access to a medium using SDM, TDM, FDM, or CDM.
Thus MAC is similar to traffic regulations in the highway/multiplexing.
E. g. several vehicles use the same street crossing in TDM, which
requires rules to avoid collisions; one mechanism to enforce these
rules is traffic lights.
10. Continued..
MAC belongs to layer 2, the data link control layer (DLC). Layer 2
is subdivided into the logical link control (LLC), layer 2b, and
the MAC, layer 2a.
The task of DLC is to establish a reliable point to point or point to
multi-point connection between different devices over a wired or
wireless medium.
LLC and MAC sub-layers
11. Continued……
The MAC sub-layer acts as an interface between the Logical
Link Control (LLC) sub-layer and the network’s physical layer.
The MAC layer emulates a full-duplex logical communication
channel in a multi-point network.
This channel may provide unicast, multicast or broadcast
communication service.
