Data Communication Data Networking Topic Wireless LAN IEEE

Data Communication & Data Networking Topic: Wireless LAN, IEEE 802. 11, Bluetooth, Virtual Circuit Group Members: Ankita Pattanaik Vivash Kr. Pandey Rakesh Kr. Jena Soumya Shree Rath Vivek Kumar

Wireless LAN q A wireless local area network (WLAN) links two or more devices. q Typically based on Spread-spectrum or ODFM radio. q WLANs are based on IEEE 802. 11 standards, marketed under the Wi-Fi brand name. q An embedded Router Board 112 with U. FL-RSMA pigtail and R 52 mini. PCI Wifi card widely used by Wireless internet service providers (WISPs). q It uses an UDP Protocol. q Norman Abramson, a professor at the University of Hawaii, developed the world’s first wireless computer communication network, ALOHAnet, using low-cost ham-like radios.

Generation of Wireless LAN q first generation wireless data modems: developed in the early 1980's by amateur communication groups. added a voice band data communication modem, with data rates below 9600 bps, such as a walkie talkie. q Second generation wireless data modems: non-military use of the spread spectrum technology. These modems provided data rates on the order of hundreds of Kbps. q Third generation wireless data modems: compatibility with the existing LANs with data rates on the order of Mbps. Currently, several companies are developing the third generation products with data rates above 1 Mbps and a couple of products have already been announced.

Examples of Wireless LAN q Wifi: q ”wireless fidelity” and is meant to be used generically when referring of any type of 802. 11 network. q Popular technology that allows an electronic device to exchange data wirelessly (using radio waves) over a computer network, including high-speed Internet connections. q Wi-Fi is designed as a wireless extension to local area networks (LAN) for indoor use with a range up to 100 m. q It uses a standard protocol of 802. 11 a/b/g/n. q It uses a frequency of 2. 5 Ghz to 5. 8 Ghz for data transmision and a data rate of 54 mbps.

Examples of Wireless LAN q Wi. Max: q “Worldwide Interoperability for Microwave Access” q Wi. MAX was originally designed to provide fixed BWA in metropolitan area networks (MAN) with a range of up to 50 km. q Wimax network operate at 60 MHz frequency and data rate is 1 Gbit/s for fixed stations q The original IEEE 802. 16 standard (now called "Fixed Wi. MAX") was published in 2001.

IEEE 802. 11 protocol q IEEE 802. 11 is a set of standards for implementing wireless local area network (WLAN) computer communication in the 2. 4, 3. 6 and 5 GHz frequency bands. q 802. 11 technology has its origins in a 1985 ruling by the U. S. Federal Communications Commission that released the ISM band for unlicensed use. q In 1991 NCR Corporation /AT&T (now Alcatel-Lucent and LSI Corporation) invented 802. 11. q Vic Hayes , who held the chair of IEEE 802. 11 for 10 years and has been called the "father of Wi-Fi" was involved in designing the initial 802. 11 b and 802. 11 a standards within the IEEE. q The original version of the standard IEEE 802. 11 was released in 1997 and updated itself in 1999, but is today obsolete q It specified two net bit rates of 1 or 2 megabits per second (Mbit/s).

Types of IEEE 802. 11 protocol q 4 Types of IEEE 802. 11 protocol: q 802. 11 a q 802. 11 b q 802. 11 g q 802. 11 n

IEEE 802. 11 a protocol q IEEE 802. 11 a-1999 q The 802. 11 a standard uses the same data link layer protocol and frame format as the original standard. q It operates in the 5 GHz frequency with net data rate of 54 Mbit/s. 802. 11 a signals are absorbed more readily by walls and other solid objects in their path due to their smaller wavelength. Higher hardware equipment costs. q q Pros of 802. 11 a - fast maximum speed; regulated frequencies prevent signal interference from other devices Cons of 802. 11 a - highest cost; shorter range signal that is more easily obstructed

IEEE 802. 11 b protocol q IEEE 802. 11 b-1999 q 802. 11 b has a maximum data rate of 11 Mbit/s q 802. 11 b products appeared on the market in early 2000 q 802. 11 b devices suffer interference from other products operating in the 2. 4 GHz band. Devices include are microwave ovens, Bluetooth devices, cordless telephones and some amateur radio equipment. q Pros of 802. 11 b - lowest cost; signal range is good and not easily obstructed Cons of 802. 11 b - slowest maximum speed; home appliances may interfere on the unregulated frequency band

IEEE 802. 11 g protocol q q q IEEE 802. 11 g-2003 In June 2003, a third modulation standard was rectified: 802. 11 g. It operates at a maximum physical layer bit rate of 54 Mbit/s most dual-band 802. 11 a/b products became dual-band/trimode, supporting a and b/g in a single mobile adapter card or access point. uses the 2. 4 Ghz frequency for greater range. Pros of 802. 11 g - fast maximum speed; signal range is good and not easily obstructed Cons of 802. 11 g - costs more than 802. 11 b; appliances may interfere on the unregulated signal frequency

IEEE 802. 11 n protocol q IEEE 802. 11 n-2009 q Uses multiple-input multiple-output antennas (MIMO). q Operates on both the 2. 4 GHz and the lesser used 5 GHz bands. q It operates at a maximum net data rate from 54 Mbit/s to 600 Mbit/s. Pros of 802. 11 n - fastest maximum speed and best signal range; more resistant to signal interference from outside sources Cons of 802. 11 n - standard is not yet finalized; costs more than 802. 11 g; the use of multiple signals may greatly interfere with nearby 802. 11 b/g based networks

Bluetooth q Bluetooth(R) wireless technology is a open wireless technology standard for exchanging data over short distances (using short-wavelength radio transmissions. q Bluetooth uses a radio technology called frequencyhopping spread spectrum. q Creating personal area networks (PANs) with high levels of security q Created by telecoms vendor Ericsson in 1994, it was originally conceived as a wireless alternative to. RS-232 data cables.

Bluetooth q Bluetooth is a packet-based protocol with a master-slave structure. One master may communicate with up to 7 slaves. q Bluetooth is managed by the Bluetooth Special Interest Group, (SIG)which has more than 16, 000 member companies in the areas of telecommunication, computing, networking, and consumer electronics. q Bluetooth provides a secure way to connect and exchange information between devices such as faxes, mobile phones, telephones, laptops, personal computers, printers, Global Positioning System(GPS) receivers, digital cameras, and video game consoles. q Protocols used: PPP, TCP/IP/UDP, OBEX , WAE/WAP

Versions of Bluetooth q Bluetooth v 1. 0 and v 1. 0 B: Interoperable connection problems , mandatory requirement of device address. q Bluetooth v 1. 1: q Bluetooth v 1. 2: IEEE Standard 802. 15. 1 -2005 Compatible with v 1. 1, faster IEEE Standard 802. 15. 1 -2002 , Many errors found in the v 1. 0 B specifications were fixed , Received Signal Strength Indicator (RSSI ). connection & discovery, transmission data rate upto 721 kbps. q Bluetooth v 2. 0 + EDR: Compatible with previous version, Enhanced data rate with 3 mbps q Bluetooth v 2. 1 + EDR: Compatible with previous version, uses Secure Simple Passing(SSP) technique q Bluetooth v 3. 0 + HS: Uses 802. 11 link, data transfer of high speeds of up to 24 Mbit/s q Bluetooth v 4. 0: Includes Classic Bluetooth, Bluetooth high speed and Bluetooth low energy protocols.

Virtual Circuit q. A virtual circuit is a circuit or path between points in a network that appears to be a discrete, physical path but is actually a managed pool of circuit resources from which specific circuits are allocated as needed to meet traffic requirements. q. A permanent virtual circuit (PVC) is a virtual circuit that is permanently available to the user just as though it were a dedicated or leased line continuously reserved for that user. q PVCs are an important feature of frame relay networks. q A switched virtual circuit (SVC) is a virtual circuit in which a connection session is set up for a user only for the duration of a connection.

Virtual Circuit q virtual circuit (VC), synonymous with virtual connection and virtual channel , is a connection oriented communication service that is delivered by means of packet mode communication. q After a connection or virtual circuit is established between two nodes or application processes, a bit stream or byte stream may be delivered between the nodes q A virtual circuit protocol allows higher level protocols to avoid dealing with the division of data into segments, packets, or frames

Virtual Circuit q Examples of protocols that provide virtual circuit Transmission Control Protocol (TCP), where a reliable virtual circuit is established on top of the underlying unreliable and connectionless IP protocol. Stream Control Transmission Protocol (SCTP), where a virtual circuit is established on top of either the IP protocol or the UDP protocol. q Examples of network layer and datalink layer virtual circuit protocols, where data always is delivered over the same path: X. 25 , where the VC is identified by a virtual channel identifier (VCI). X. 25 provides reliable node-to-node communication and guaranty Frame relay, where the VC is identified by a VCI. Frame relay is unreliable, but may provide guaranteed Qo. S. Asynchronous Transfer Mode (ATM), where the circuit is identified by a virtual path identifier (VPI) and virtual channel identifier (VCI) pair. ATM is unreliable, but may provide guaranteed Qo. S. General Packet Radio Service (GPRS) Multiprotocol label switching(MPLS), which can be used for IP over virtual circuits. Each circuit is identified by a label. MPLS is unreliable, but provides eight different Qo. S classes.

Refrence http: //en. wikipedia. org/wiki/Wireless_LAN http: //www. usr. com/download/whitepapers/wireless-wp. pdf http: //en. wikipedia. org/. . . /Institute_of_Electrical_and_Electronics _Enginee http: //en. wikipedia. org/wiki/IEEE_802. 11 http: //www. compnetworking. about. com ›. . . › Wi-Fi Wireless http: //en. wikipedia. org/wiki/Bluetooth http: //en. wikipedia. org/wiki/Virtual_circuit http: //www. webopedia. com/TERM/V/virtual_circuit. html

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