hos presentation

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Presentation on WLAN Wireless LAN

Contents : 

Contents Introduction Types of Networks Local Area Network Wireless LAN Components WLAN Types of WLAN Peer to Peer Bridge Wireless Distribution System Benefits of WLAN

What is network??? : 

What is network???

Types of networks : 

Types of networks Personal area network Local area network Metropolitan area network Wide area network

LAN (Local Area Network) : 

LAN (Local Area Network) Covering a small physical area. Based on Ethernet technology. On a wired LAN, PCs are typically connected by category 5 (Cat5) cable IEEE 802.3 protocol through a system of interconnected devices is used.

WLAN (Wireless LAN) : 

WLAN (Wireless LAN) Provide wireless network communication over short distances . Uses radio or infrared signals Linking of two or more computers in a limited area.

WLAN (Wireless LAN) : 

WLAN (Wireless LAN) Become popular due to ease of installation. Location freedom with the gaining popularity of laptops. Public businesses such as coffee shops or malls have begun to offer wireless access to their customers.

WLAN (Wireless LAN) : 

WLAN (Wireless LAN) WLAN typically extends an existing wired local area network. Wireless access points (APs or WAPs) are specially configured nodes on wireless local area networks (WLANs). Access points act as a central transmitter and receiver of WLAN radio signals.

Components of WLAN : 

Components of WLAN Wireless Client Receiver Access Point WLAN Antennas

Wireless Client Receiver : 

Wireless Client Receiver Wireless LAN client receivers are needed to connect a computing device , via an access point. The receiver takes care of data processing in the physical and MAC layer of the OSI framework. Depending on the interfaces of the computing devices, there are different forms of receivers.

Access Point : 

Access Point Are needed only in the Infrastructure Mode of WLANs. They provide the wireless clients with a point of access into a network. They are comparable to a sophisticated Ethernet switch.

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Access Point : 

Access Point Operate in half-duplex mode, i.e. they either receive or transmit at a given time. Three modes of operation known as Root Mode, Bridge Mode Repeater Mode

Root Mode : 

Root Mode The AP is connected to a wired network and the wireless client directly accesses this network via the AP. Several clients can talk to each other by means of using APs that are connected to the same backbone network. Root Mode is the default configuration of most APs.

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Bridge Mode : 

Bridge Mode Makes it possible to wirelessly connect two separate wired network segments with each other. No clients use the AP to enter a network. Found in a few commercially available APs, which are significantly more expensive.

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Bridge Mode

Repeater Mode : 

Repeater Mode Provides a wireless upstream link into a network instead of being hard-wired to the network and using its Ethernet port. It functions as intermediary between the clients and an AP in root mode for entry into the network. Extend the perceived range of a WLAN or to make WLAN deployment possible in difficult environments.

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Repeater Mode

Repeater Mode : 

Repeater Mode Since an AP in repeater mode connects to another AP (root mode) and the wireless clients, its throughput is reduced dramatically. The repeater mode should only be used if absolutely necessary.

WLAN Antennas : 

WLAN Antennas The wireless transmission of data and voice necessarily needs antennas – at sender and receiver – for proper operation. The selection of appropriate antennas can impact the functionality of a system dramatically. Proper installation of the antenna is crucial.

WLAN Antennas : 

WLAN Antennas Adding an antenna does not increase the power But focuses it in a particular direction as to increase reception.

WLAN Antennas : 

WLAN Antennas There are a wide range of antennas available on the market: Onmidirectional Antennas Sectorized Antennas Parabolic (dish) Antennas

Onmidirectional Antennas : 

Onmidirectional Antennas Radiate the signal outward equally in all directions. They are shaped like a tall pole and have their highest sensitivity in horizontal direction. They are used to cover large areas where the exact location of the receiver is unknown. Picks up a lot of noise surrounding it and distributes the transmit power over all directions making for a weaker signal.

Sectorized Antennas : 

Sectorized Antennas Have reflectors behind the pole that direct the transmitted energy in a certain direction. This kind of antenna is used when multiple clients need to access an AP from the same direction. They increase range and decrease interference.

Parabolic (dish) Antennas : 

Parabolic (dish) Antennas The most directional antennas ,Deliver the highest gains. They are tightly focused on a distinct direction, which makes them ideal for point-to-point operations. The dish can either be a meshed wire grid or solid metal. The diameter ranges from several inch to a few feet. A correctly aligned pair of parabolic antennas can extend the range of wireless networks up to 20 miles.

Types of WLAN : 

Types of WLAN Peer-to-peer Bridge Wireless distribution system

Peer-to-peer : 

Peer-to-peer Peer-to-Peer or ad-hoc wireless LAN

Bridge : 

Bridge

Wireless distribution system : 

Wireless distribution system

Benefits of WLAN : 

Benefits of WLAN Convenience Mobility Productivity

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Benefits of WLAN 4. Deployment 5. Expandability 6. Cost

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Thanx Any queries ???