Computer Networks and Communications2
Content
Computer Networks and
Communications
NAME
:
IC/NO
:
CLASS
: 4 Mulia
1.0
INTRODUCTION
(Computer Network and Communication)
Today computer is available in many offices and homes and
therefore there is a need to share data and programs among
various
computers
with
the
advancement
of
data
communication
facilities.
The
communication
between
computers has increased and it thus it has extended the power
of computer beyond the computer room. Now a user sitting at
one place can communicate computers of any remote sites
through communication channel. The aim of this chapter is to
introduce you the various aspects of computer network.
2.0
MOBILE COMPUTING
2.1
DEFINITION
Mobile Computing is an umbrella term used to describe
technologies that enable people to access network services
anyplace, anytime, and anywhere. Ubiquitous computing and
nomadic computing are synonymous with mobile computing.
Information access via a mobile device is plagued by low
available bandwidth, poor connection maintenance, poor
security, and addressing problems. Unlike their wired
counterparts, design of software for mobile devices must
consider resource limitation, battery power and display size.
Consequently, new hardware and software techniques must be
developed.
2.2
SPECIFICATION, SERVIS AND FREQUENCIES OF MOBILE
COMPUTING
SPECIFICATION
The S60 5th Edition has a lot of goodness in technology. It
has3.5-inch TFT and 16 million colours. The widescreen also
about mHDIt has 640×360 pixels and it use the Nokia Battery
BP-4L that is about 1500 mAh. The memoryis about up to 48GB
which is 32GB Internal Memory and 16GB Micro SD Expansion
Slot. Themain camera use the Carl Zeiss Tessar Lens and it is
about 5MP (2584 x 1938). The format of the picture is JPEG/EXIF
(16.7 Million / 24-bit color) and the video capture is MPEG-4
VGA,640×480 at 30fps. The camera aperture is about F2.8 and
the focal length is 5.4mm. Thistechnology use Dual LED
Camera for the flash.
SERVICES
For its service, it has WLAN IEEE 802.11 b/g with UPnP support,
Micro USB Connector plus 3.5 mm stereo headphone plug. It
also has TV-Out Support, data transfer via Bluetooth 2.0,A-GPS
and Internet surfing
FREQUENCIES
Its frequencies are up to 2G Network GSM 850 / 900 / 1800 /
1900 and 3G Network HSDPA 900 / 1900 / 2100
3.0
INTERNET TECHNOLOGY AND SERVICES
3.1
VoIP
Voice Over IP is a telephone service that uses the Internet as a
global telephone network. Many companies, including Vonage,
8×8 and AT&T (CallVantage), typically offer calling within the
country for a fixed fee and a low per-minute charge for
international. Broadband Internet access (cable or DSL) is
required, and regular house phones plug into an analog
telephone adapter (ATA) provided by the company or purchased
from a third party.
3.2
BLOG
A blog is a lot like a journal except it is generally intended to be
read by others. The topics for blogs vary greatly; some being
about day to day activities and others taking a more corporate
or political slant. There is no defined or widely accepted format
and so blogs range from one liners that the author adds every
few hours to relatively long, well thought out arguments for or
against a topic of interest.
4.0
TYPE OF NETWORK
4.1
PAN
A Personal Area Network (PAN) is a computer network used for
communication among computer devices (including telephones
and personal digital assistants) close to one person. The
devices may or may not belong to the person in question. The
reach of a PAN is typically a few meters. PANs can be used for
communication among the personal devices themselves
(intrapersonal communication), or for connecting to a higher
level network and the Internet (an uplink). Personal area
networks may be wired with computer buses such
asUSB and FireWire. A wireless personal area network (WPAN)
can also be made possible with network technologies such
as IrDA and Bluetooth.
4.2
VPN
Short for (Virtual Private Network), VPN is a type of network
that allows a user to connect to a network through a
tunneling protocol and access internal internet and intranet
web sites and e-mail. Virtual Private Networks are commonly
used to allow an employee with a large company to connect to
the company’s intranet.
4.3
WLAN
A Wireless Local Area Network, sometimes referred to as LAWN
( local area wireless network ) is one in which a mobile user can
connect to a local area network (LAN) through a wireless (radio)
connection. The IEEE 802.11 group of standards specify the
technologies for wireless LANs. 802.11 standards use
the Ethernetprotocol and CSMA/CA (carrier sense multiple
access with collision avoidance) for path sharing and include an
encryption method, the Wired Equivalent Privacy algorithm. A
personal area network.
4.4
WIMAX
WiMax is the industry term for a long-range wireless networking
standard. WiMax technology has the potential to deliver highspeed Internet access to rural areas and other locations not
serviced by cable or DSL technology. WiMax also offers an
alternative to satellite Internet services. WiMax technology is
based on the IEEE 802.16 WANcommunications standard.
WiMax signals can function over a distance of several miles /
kilometres. Data rates for WiMax can reach up to 75 megabits
per second (Mb/s). A number of wireless signalling options exist
ranging anywhere from the 2 GHz range up to 66 GHz.
5.0
CONCLUSION
Mobile computing (like the peer to peer transaction
model did) brings about a new paradigm of distributed
computing in which communication may be achieved through
wireless networks and users can compute even as they relocate
from one support environment to another. The impact of mobile
computing on systems design goes beyond the networking
level and directly effects data management. Although being a
relatively new area, mobile data management has attracted a
lot of research efforts, motivated by both a great market
potential and by many challenging research problems
REFERENCE
http://smklangkawi.edu.my/blogict/?p=7
http://www.wimax.com/deployment/network
http://en.wikipedia.org/wiki/Computer_network
Communications
NAME
:
IC/NO
:
CLASS
: 4 Mulia
1.0
INTRODUCTION
(Computer Network and Communication)
Today computer is available in many offices and homes and
therefore there is a need to share data and programs among
various
computers
with
the
advancement
of
data
communication
facilities.
The
communication
between
computers has increased and it thus it has extended the power
of computer beyond the computer room. Now a user sitting at
one place can communicate computers of any remote sites
through communication channel. The aim of this chapter is to
introduce you the various aspects of computer network.
2.0
MOBILE COMPUTING
2.1
DEFINITION
Mobile Computing is an umbrella term used to describe
technologies that enable people to access network services
anyplace, anytime, and anywhere. Ubiquitous computing and
nomadic computing are synonymous with mobile computing.
Information access via a mobile device is plagued by low
available bandwidth, poor connection maintenance, poor
security, and addressing problems. Unlike their wired
counterparts, design of software for mobile devices must
consider resource limitation, battery power and display size.
Consequently, new hardware and software techniques must be
developed.
2.2
SPECIFICATION, SERVIS AND FREQUENCIES OF MOBILE
COMPUTING
SPECIFICATION
The S60 5th Edition has a lot of goodness in technology. It
has3.5-inch TFT and 16 million colours. The widescreen also
about mHDIt has 640×360 pixels and it use the Nokia Battery
BP-4L that is about 1500 mAh. The memoryis about up to 48GB
which is 32GB Internal Memory and 16GB Micro SD Expansion
Slot. Themain camera use the Carl Zeiss Tessar Lens and it is
about 5MP (2584 x 1938). The format of the picture is JPEG/EXIF
(16.7 Million / 24-bit color) and the video capture is MPEG-4
VGA,640×480 at 30fps. The camera aperture is about F2.8 and
the focal length is 5.4mm. Thistechnology use Dual LED
Camera for the flash.
SERVICES
For its service, it has WLAN IEEE 802.11 b/g with UPnP support,
Micro USB Connector plus 3.5 mm stereo headphone plug. It
also has TV-Out Support, data transfer via Bluetooth 2.0,A-GPS
and Internet surfing
FREQUENCIES
Its frequencies are up to 2G Network GSM 850 / 900 / 1800 /
1900 and 3G Network HSDPA 900 / 1900 / 2100
3.0
INTERNET TECHNOLOGY AND SERVICES
3.1
VoIP
Voice Over IP is a telephone service that uses the Internet as a
global telephone network. Many companies, including Vonage,
8×8 and AT&T (CallVantage), typically offer calling within the
country for a fixed fee and a low per-minute charge for
international. Broadband Internet access (cable or DSL) is
required, and regular house phones plug into an analog
telephone adapter (ATA) provided by the company or purchased
from a third party.
3.2
BLOG
A blog is a lot like a journal except it is generally intended to be
read by others. The topics for blogs vary greatly; some being
about day to day activities and others taking a more corporate
or political slant. There is no defined or widely accepted format
and so blogs range from one liners that the author adds every
few hours to relatively long, well thought out arguments for or
against a topic of interest.
4.0
TYPE OF NETWORK
4.1
PAN
A Personal Area Network (PAN) is a computer network used for
communication among computer devices (including telephones
and personal digital assistants) close to one person. The
devices may or may not belong to the person in question. The
reach of a PAN is typically a few meters. PANs can be used for
communication among the personal devices themselves
(intrapersonal communication), or for connecting to a higher
level network and the Internet (an uplink). Personal area
networks may be wired with computer buses such
asUSB and FireWire. A wireless personal area network (WPAN)
can also be made possible with network technologies such
as IrDA and Bluetooth.
4.2
VPN
Short for (Virtual Private Network), VPN is a type of network
that allows a user to connect to a network through a
tunneling protocol and access internal internet and intranet
web sites and e-mail. Virtual Private Networks are commonly
used to allow an employee with a large company to connect to
the company’s intranet.
4.3
WLAN
A Wireless Local Area Network, sometimes referred to as LAWN
( local area wireless network ) is one in which a mobile user can
connect to a local area network (LAN) through a wireless (radio)
connection. The IEEE 802.11 group of standards specify the
technologies for wireless LANs. 802.11 standards use
the Ethernetprotocol and CSMA/CA (carrier sense multiple
access with collision avoidance) for path sharing and include an
encryption method, the Wired Equivalent Privacy algorithm. A
personal area network.
4.4
WIMAX
WiMax is the industry term for a long-range wireless networking
standard. WiMax technology has the potential to deliver highspeed Internet access to rural areas and other locations not
serviced by cable or DSL technology. WiMax also offers an
alternative to satellite Internet services. WiMax technology is
based on the IEEE 802.16 WANcommunications standard.
WiMax signals can function over a distance of several miles /
kilometres. Data rates for WiMax can reach up to 75 megabits
per second (Mb/s). A number of wireless signalling options exist
ranging anywhere from the 2 GHz range up to 66 GHz.
5.0
CONCLUSION
Mobile computing (like the peer to peer transaction
model did) brings about a new paradigm of distributed
computing in which communication may be achieved through
wireless networks and users can compute even as they relocate
from one support environment to another. The impact of mobile
computing on systems design goes beyond the networking
level and directly effects data management. Although being a
relatively new area, mobile data management has attracted a
lot of research efforts, motivated by both a great market
potential and by many challenging research problems
REFERENCE
http://smklangkawi.edu.my/blogict/?p=7
http://www.wimax.com/deployment/network
http://en.wikipedia.org/wiki/Computer_network
