Data Communication & Data Networking

Group Members:

Ankita PattanaikVivash Kr. PandeyRakesh Kr. JenaSoumya Shree RathVivek Kumar

Topic: Wireless LAN, IEEE 802.11,Bluetooth, Virtual Circuit

Wireless LAN A wireless local area network (WLAN) links two or more

devices.

Typically based on Spread-spectrum or ODFM radio.

WLANs are based on IEEE 802.11 standards, marketed under the

Wi-Fi brand name.

An embedded  Router Board 112 with U.FL-RSMA pigtail and R52miniPCI Wifi card widely used by Wireless internet service providers (WISPs).

It uses an UDP Protocol .

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 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.

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.

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 Wifi:

 ”wireless fidelity” and is meant to be used generically when referring of any type of 802.11  network.

Popular technology that allows an electronic device to exchange data wirelessly (using radio waves) over a computer network, including high-speed Internet connections.

Wi-Fi is designed as a wireless extension to local area networks (LAN) for indoor use with a range up to 100m.

It uses a standard protocol of 802.11 a/b/g/n.

It uses a frequency of 2.5 Ghz to 5.8 Ghz for data transmision and a data rate of 54mbps.

Examples of Wireless LAN WiMax:

“Worldwide Interoperability for Microwave Access”

WiMAX was originally designed to provide fixed BWA in metropolitan area networks (MAN) with a range of up to 50 km.

Wimax network operate at 60 MHz frequency and data rate is 1 Gbit/s for fixed stations

The original IEEE 802.16 standard (now called "Fixed WiMAX") was published in 2001. 

IEEE 802.11 protocol 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.

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.

In 1991 NCR Corporation /AT&T (now Alcatel-Lucent  and LSI Corporation) invented 802.11.

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 802.11b and 802.11a standards within the IEEE .

The original version of the standard IEEE 802.11 was released in 1997 and updated itself in 1999, but is today obsolete

It specified two net bit rates of 1 or 2 megabits per second  (Mbit/s).

Types of IEEE 802.11 protocol

4 Types of IEEE 802.11 protocol:

802.11 a802.11 b802.11 g802.11 n

IEEE 802.11 a protocol IEEE 802.11a-1999

The 802.11a standard uses the same data link layer protocol and frame format as the original standard.

It operates in the 5 GHz frequency with net data rate of 54 Mbit/s .

802.11a signals are absorbed more readily by walls and other solid objects in their path due to their smaller wavelength .

Higher hardware equipment costs.

Pros of 802.11a - fast maximum speed; regulated frequencies prevent signal interference from other devices

Cons of 802.11a - highest cost; shorter range signal that is more easily obstructed

IEEE 802.11 b protocol IEEE 802.11b-1999

802.11b has a maximum data rate of 11 Mbit/s

802.11b products appeared on the market in early 2000

802.11b 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.

Pros of 802.11b - lowest cost; signal range is good and not easily obstructed

Cons of 802.11b - slowest maximum speed; home appliances may interfere on the unregulated frequency band

IEEE 802.11 g protocol IEEE 802.11g-2003 In June 2003, a third modulation standard was

rectified: 802.11g. It operates at a maximum physical layer bit rate of

54 Mbit/s most dual-band 802.11a/b products became dual-

band/tri-mode, 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 802.11g - fast maximum speed; signal range is good and not easily obstructed

Cons of 802.11g - costs more than 802.11b; appliances may interfere on the unregulated signal frequency

IEEE 802.11 n protocol  IEEE 802.11n-2009

Uses multiple-input multiple-output antennas (MIMO).

Operates on both the 2.4 GHz and the lesser used 5 GHz bands.

It operates at a maximum net data rate from 54 Mbit/s to 600 Mbit/s.

Pros of 802.11n - fastest maximum speed and best signal range; more resistant to signal interference from outside sources

Cons of 802.11n - standard is not yet finalized; costs more than 802.11g; the use of multiple signals may greatly interfere with nearby

802.11b/g based networks

Bluetooth Bluetooth(R) wireless technology is a open

wireless technology standard for exchanging data over short distances (using short-wavelength radio transmissions.

Bluetooth uses a radio technology called frequency-hopping spread spectrum.

Creating personal area networks (PANs) with high levels of security

Created by telecoms vendor Ericsson  in 1994,it was originally conceived as a wireless alternative toRS-232 data cables.

Bluetooth Bluetooth is a packet-based protocol with a master-slave structure.

One master may communicate with up to 7 slaves .

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.

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.

Protocols used: PPP,TCP/IP/UDP, OBEX ,WAE/WAP

Versions of Bluetooth Bluetooth v1.0 and v1.0B: Interoperable connection

problems ,mandatory requirement of device address.

Bluetooth v1.1:  IEEE Standard 802.15.1-2002 , Many errors found in the v1.0B specifications were fixed , Received Signal Strength Indicator (RSSI ).

Bluetooth v1.2:  IEEE Standard 802.15.1-2005 Compatible with v1.1,faster connection & discovery, transmission data rate upto 721kbps.

Bluetooth v2.0 + EDR: Compatible with previous version, Enhanced data rate with 3mbps

Bluetooth v2.1 + EDR: Compatible with previous version,uses Secure Simple Passing(SSP) technique

Bluetooth v3.0 + HS: Uses 802.11 link, data transfer of high speeds of up to 24 Mbit/s

Bluetooth v4.0:  Includes Classic Bluetooth, Bluetooth high speed and Bluetooth low energy  protocols.

Virtual CircuitA 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.

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. 

 PVCs are an important feature of frame relay networks .

 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 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.

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

 A virtual circuit protocol allows higher level protocols to avoid dealing with the division of data into segments, packets, or frames

Virtual Circuit Examples of protocols that provide virtual circuitTransmission 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.

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 QoS.

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 QoS.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 QoS classes.    

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

Refrence

Thankyou