27-08-2014, 02:01 PM
WIRELESS FIDELITY
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ABSTRACT
Technology is no longer judged by its technical brilliance, but by the return on investment (both tangible and intangible). This in turn, is dictated by the killer application for that technology. Wireless Networks fit into this because the technology has been around long enough and can provide enough benefits to be seriously considered for deployment.
At the enterprise, it provides communication support for mobile computing. It overcomes and, in fact, annihilates the physical limitation of wired networks in terms of adaptability to a variation in demand. Network connectivity in a company’s meeting room is a classic example. The number of users using that room would vary for different meetings. So, it would be difficult to decide how many wired network ports to put there. With wireless access, the number of users is mostly constrained by the bandwidth available on the wireless network.
Mobility is another feature by wireless. Mobile users can be truly mobile, in that hey don’t need to be bound to their seats when connecting to the network. Mobility, however is not only associated with users, it’s also associated with the infrastructure itself. You can have a wireless network up and running in no time, a boon for people who need to do it for exhibitions, events, etc.
This leads to other provision of wireless, that of scalability. It really helps in extending your network. It also becomes important if an enterprise has a rented office and needs to shift to a new place. At home, the need for wireless is more to do with ubiquitous computing. Wi-Fi, or wireless fidelity, is freedom: it allows you to connect to the Internet from your couch at home, a bed in a hotel room, or a conference room at work without wires.
Wireless technology, therefore is really happening, and should be seriously considered. The following presentation explains introduction to Wi-Fi ,functionality, wireless LANs, their basic operations, topologies, security features, technical features , and answers some of the questions evaluating WLAN technology.
Introduction to Wi-Fi
Wireless Fidelity, better known as Wi-Fi, is a term
used to describe the underlying technology of
wireless local area networks (WLAN) based on the
Institute of Electrical and Electronics Engineers
(IEEE) 802.11 standards. Initially intended to
connect mobile computing devices in local area
networks (LAN), Wi-Fi applications have grown to
include various data, voice, and video services such
as Internet access and Voice over Internet Protocol
(VoIP) [2, 3]. With the growing popularity of small
portable devices, a wireless network connection
proves more beneficial by minimizing expensive
deployment costs, providing user mobility, and
supporting high bandwidth and quality of service
(QoS) needs compared with traditional wired LANs.
In addition, various IEEE 802.11 standards now in
development are aimed to increase the performance
of Wi-Fi networks and to provide users with greater
flexibility in wireless communications.
Wi-Fi technology platform is based on single-carrier
direct-sequence spread spectrum (DSSS) and multi-
carrier Orthogonal Frequency Division Multiplexing
(OFDM) radio technologies to transmit and receive
signals. The original version of the standard, now
referred to as “802.11legacy,” was released in 1997
and had specified a maximum data rate of 2 Megabits
per second (Mbps), which was considered too slow to
support many high-data rate applications (e.g., video
telephony) [4, 5]. The IEEE 802.11 standards family
consists of many amendments and service
enhancements to the original standard, with the most
popular being the “a,” “b,” and “g” standards.
Although the 802.11a standard was the first
standard created in the 802.11 family, the
802.11b standard became the first widely accepted
wireless networking standard, later followed by
802.11a and 802.11g.
Wi-Fi is more commonly used in point-to-multipoint
(PMP) environments to allow extended network
connectivity (e.g., private/backbone network,
Internet) of multiple portable devices such as
laptops, telephones, or PDAs. Wi-Fi also allows
connectivity in point-to-point (P2P) mode, which
enables devices to directly connect and communicate
to each other. A region covered by one or more APs
is considered a “hotspot.” Home networks
commonly deploy one AP that is typically connected
directly to an Internet service provider (ISP), whereas
larger networks (e.g., enterprises, small businesses)
may require at least several APs positioned in
strategic locations to provide flexibility of service to
a large number of users [2]. Because of range
constraints, Wi-Fi networks are used in localized
regions. Figure 1 illustrates the components of a
common Wi-Fi network.
Multiple Access
The basic access method for 802.11 is the Distributed Coordination Function (DCF) which uses Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA). This requires each station to listen for other users. If the channel is idle, the station may transmit. However if it is busy, each station waits until transmission stops, and then enters into a random back off procedure. This prevents multiple stations from seizing the medium immediately after completion of the preceding transmission.
Conclusion:
The use of wireless LANs is expected to increase dramatically in the future as businesses discover the enhanced productivity and the increased mobility that wireless communications can provide in a society that is moving towards more connectionless connections.
In conclusion, the panelists felt that hurdles in deploying WLANs can be overcome. Cost of wireless services are already falling. The issue is now to lower the costs of the device that is needed to access the WLAN. Lar2__hop design companies can make use of this opportunity to get into the market place. And Wi-Fi cannot move ahead quickly without support form private and government sectors
[attachment=67144]
ABSTRACT
Technology is no longer judged by its technical brilliance, but by the return on investment (both tangible and intangible). This in turn, is dictated by the killer application for that technology. Wireless Networks fit into this because the technology has been around long enough and can provide enough benefits to be seriously considered for deployment.
At the enterprise, it provides communication support for mobile computing. It overcomes and, in fact, annihilates the physical limitation of wired networks in terms of adaptability to a variation in demand. Network connectivity in a company’s meeting room is a classic example. The number of users using that room would vary for different meetings. So, it would be difficult to decide how many wired network ports to put there. With wireless access, the number of users is mostly constrained by the bandwidth available on the wireless network.
Mobility is another feature by wireless. Mobile users can be truly mobile, in that hey don’t need to be bound to their seats when connecting to the network. Mobility, however is not only associated with users, it’s also associated with the infrastructure itself. You can have a wireless network up and running in no time, a boon for people who need to do it for exhibitions, events, etc.
This leads to other provision of wireless, that of scalability. It really helps in extending your network. It also becomes important if an enterprise has a rented office and needs to shift to a new place. At home, the need for wireless is more to do with ubiquitous computing. Wi-Fi, or wireless fidelity, is freedom: it allows you to connect to the Internet from your couch at home, a bed in a hotel room, or a conference room at work without wires.
Wireless technology, therefore is really happening, and should be seriously considered. The following presentation explains introduction to Wi-Fi ,functionality, wireless LANs, their basic operations, topologies, security features, technical features , and answers some of the questions evaluating WLAN technology.
Introduction to Wi-Fi
Wireless Fidelity, better known as Wi-Fi, is a term
used to describe the underlying technology of
wireless local area networks (WLAN) based on the
Institute of Electrical and Electronics Engineers
(IEEE) 802.11 standards. Initially intended to
connect mobile computing devices in local area
networks (LAN), Wi-Fi applications have grown to
include various data, voice, and video services such
as Internet access and Voice over Internet Protocol
(VoIP) [2, 3]. With the growing popularity of small
portable devices, a wireless network connection
proves more beneficial by minimizing expensive
deployment costs, providing user mobility, and
supporting high bandwidth and quality of service
(QoS) needs compared with traditional wired LANs.
In addition, various IEEE 802.11 standards now in
development are aimed to increase the performance
of Wi-Fi networks and to provide users with greater
flexibility in wireless communications.
Wi-Fi technology platform is based on single-carrier
direct-sequence spread spectrum (DSSS) and multi-
carrier Orthogonal Frequency Division Multiplexing
(OFDM) radio technologies to transmit and receive
signals. The original version of the standard, now
referred to as “802.11legacy,” was released in 1997
and had specified a maximum data rate of 2 Megabits
per second (Mbps), which was considered too slow to
support many high-data rate applications (e.g., video
telephony) [4, 5]. The IEEE 802.11 standards family
consists of many amendments and service
enhancements to the original standard, with the most
popular being the “a,” “b,” and “g” standards.
Although the 802.11a standard was the first
standard created in the 802.11 family, the
802.11b standard became the first widely accepted
wireless networking standard, later followed by
802.11a and 802.11g.
Wi-Fi is more commonly used in point-to-multipoint
(PMP) environments to allow extended network
connectivity (e.g., private/backbone network,
Internet) of multiple portable devices such as
laptops, telephones, or PDAs. Wi-Fi also allows
connectivity in point-to-point (P2P) mode, which
enables devices to directly connect and communicate
to each other. A region covered by one or more APs
is considered a “hotspot.” Home networks
commonly deploy one AP that is typically connected
directly to an Internet service provider (ISP), whereas
larger networks (e.g., enterprises, small businesses)
may require at least several APs positioned in
strategic locations to provide flexibility of service to
a large number of users [2]. Because of range
constraints, Wi-Fi networks are used in localized
regions. Figure 1 illustrates the components of a
common Wi-Fi network.
Multiple Access
The basic access method for 802.11 is the Distributed Coordination Function (DCF) which uses Carrier Sense Multiple Access / Collision Avoidance (CSMA / CA). This requires each station to listen for other users. If the channel is idle, the station may transmit. However if it is busy, each station waits until transmission stops, and then enters into a random back off procedure. This prevents multiple stations from seizing the medium immediately after completion of the preceding transmission.
Conclusion:
The use of wireless LANs is expected to increase dramatically in the future as businesses discover the enhanced productivity and the increased mobility that wireless communications can provide in a society that is moving towards more connectionless connections.
In conclusion, the panelists felt that hurdles in deploying WLANs can be overcome. Cost of wireless services are already falling. The issue is now to lower the costs of the device that is needed to access the WLAN. Lar2__hop design companies can make use of this opportunity to get into the market place. And Wi-Fi cannot move ahead quickly without support form private and government sectors