Subject Name: Computer Communication Networks Subject Code: 10EC71 Prepared By: Kala H S & Megha Gupta Department: ECE Date: 9/20/2018

Unit - 4 WIRED & WIRELESS LAN 9/20/2018

TOPICS TO BE COVERED Standard Ethernet Changes in the standard Fast Ethernet Gigabit Ethernet Wireless LAN 9/20/2018

STANDARD ETHERNET The original Ethernet was created in 1976 at Xerox’s Palo Alto Research Center (PARC). Since then, it has gone through four generations : Standard Ethernet (10 Mbps), Fast Ethernet (100 Mbps), Gigabit Ethernet (1 Gbps), and Ten-Gigabit Ethernet (10 Gbps). 9/20/2018

802.3 MAC Frame The frame contains seven fields: preamble, SFD, DA, SA, length or type of protocol data unit (PDU), upper-layer data. It does not provide any mechanism foe acknowledging received frames. It is an unreliable medium. Minimum frame length = 512 bits or 64 bytes, Maximum frame length = 12,144 bits or 1518 bytes. 9/20/2018

Addressing Each station on an Ethernet network has its own Network Interface Card (NIC). NIC provides a 6-byte (48 bits)physical address, normally written in hexadecimal notation, with a colon between the bytes. Unicast and Multicast Address 9/20/2018

Categories of Standard Ethernet 9/20/2018

Encoding in a Standard Ethernet implementation At sender: data are converted to a digital signal using the Manchester scheme. At receiver: the received signal is interpreted as Manchester and decoded into data. 9/20/2018

10Base5 Implementation 10Base2 implementation 9/20/2018

10Base-T Implementation 10Base-F Implementation 9/20/2018

Summary of Standard Ethernet implementations 9/20/2018

CHANGES IN THE STANDARD The 10-Mbps Standard Ethernet has gone through several changes before moving to the higher data rates. These changes actually opened the road to the evolution of the Ethernet to become compatible with other high-data-rate LANs. Bridged Ethernet Switched Ethernet Full-Duplex Ethernet 9/20/2018

Bridged Ethernet Division of a LAN by bridges. Bridges have two effects on an Ethernet LAN: raise the bandwidth and separate collision domains. Sharing bandwidth net 9/20/2018

Collision domains in an unbridged network and a bridged network 9/20/2018

Switched Ethernet The bandwidth is shared only between the station and the switch. The collision domain is divided into N domains. A layer 2 switch is an N-port bridge with additional sophistication that allows faster handling of the packets. 9/20/2018

Full-Duplex Switched Ethernet One of the limitations of 10Base5 and lOBase2 is that communication is half-duplex, a station can either send or receive, but may not do both at the same time. The next step in the evolution was to move from switched Ethernet to full-duplex switched Ethernet. The full-duplex mode increases the capacity of each domain from 10 to 20 Mbps. 9/20/2018

FAST ETHERNET It was designed to compete with LAN protocols such as FDDI or Fiber Channel. IEEE created Fast Ethernet under the name 802.3u. It is backward-compatible with Standard Ethernet, but it can transmit data 10 times faster at a rate of 100 Mbps. Topology are: 9/20/2018

Fast Ethernet Implementations Summary of Fast Ethernet implementations 9/20/2018

GIGABIT ETHERNET The need for an even higher data rate resulted in the design of the Gigabit Ethernet protocol (1000 Mbps). The IEEE committee calls the standard 802.3z. Topologies of Gigabit Ethernet: 9/20/2018

Gigabit Ethernet Implementations 9/20/2018

Summary of Gigabit Ethernet implementations 9/20/2018

TEN-GIGABIT ETHERNET It is a multiple-access method in which the available bandwidth of a link is shared in time, frequency, or through code, between different stations. Three channelization protocols: FDMA, TDMA, CDMA. 9/20/2018

WIRELESS LAN – IEEE 802.11 Architecture IEEE has defined the specifications for a wireless LAN, called IEEE 802.11, which covers the physical and data link layers. Architecture The standard defines two kinds of services: Basic Service Set (BSS) and Extended Service Set (ESS) A BSS without an AP is called an ad hoc network. A BSS with an AP is called an infrastructure network. 9/20/2018

ESS is made up of two or more BSSs with APs. BSSs are connected through a distribution system. Distribution system connects the APs in the BSSs. 9/20/2018

MAC layers in IEEE 802.11 standard 9/20/2018

CSMA/CA Flowchart 9/20/2018

CSMA/CA and NAV 9/20/2018

Frame Format Control frames 9/20/2018

Addressing Mechanism 9/20/2018

Physical Layers 9/20/2018

Physical layer of IEEE 802.11 FHSS 9/20/2018

Physical layer of IEEE 802.11 DSSS 9/20/2018

Physical layer of IEEE 802.11 Infra red 9/20/2018

Physical layer of IEEE 802.11b 9/20/2018

Acknowledgement : MY SINCERE THANKS TO By Kala H S & Megha Gupta THE AUTHOR PROF.BEHROUZ A FOROUZAN. BECAUSE THE ABOVE PRESENTATION MATERIALS ARE HEAVILY BORROWED FROM HIS TEXTBOOK “DATA COMMUNICATION & NETWORKING” 4TH EDITION, PUBLISHER TATA MCGRAW HILL SURESHA V. PROFESSOR, DEPT. OF E&C, KVG COLLEGE OF ENGINEERING. SULLIA, D.K - 574 327 By Kala H S & Megha Gupta Assistant Professor 9/20/2018