Ethernet was invented in the 1970s at Xerox PARC and was later commercialized. It is a widely used wired networking technology that uses bus topology and CSMA/CD protocol to allow multiple devices to share bandwidth on the same network. Li-Fi is a new wireless technology that uses visible light communication through LED lights to transmit data, providing a potential alternative to Wi-Fi that has benefits like higher speeds, more bandwidth availability, and better security. It was introduced in 2011 and companies are working to commercialize Li-Fi products and networks. Potential applications include use in places where radio signals cannot be used safely or are restricted.
2. Ethernet History
The original Ethernet LAN was invented in the mid 1970s by Bob
Metcalfe and David Boggs.
Ethernet was developed at Xerox PARC (Palo Alto Research
Center) between 1973 and 1974.
The idea was first documented in a memo that Metcalfe wrote on
May 22, 1973.
In 1976, after the system was deployed at PARC, Metcalfe and
Boggs published a seminal paper.
Firstly created by Robert Metcalfe in 1979 (3com corporation)
3Com Corporation was a digital electronics manufacturer best
known for it computer network products
3. What is Ethernet ?
Ethernet is a family of computer networking, technologies commonly
used in local area networks (LAN), metropolitan area networks(MAN)
and wide area networks (WAN).
Definition :-
A system for connecting a number of computer systems to form
a local area network, with protocols to control the passing of
information and to avoid simultaneous transmission by two or more
systems
Ethernet is a link layer protocol in the TCP/IP(transmission control
protocol /Internet protocol)
Ethernet uses bus topology
5. First of all two different type of computers and they should be
networked also.
NIC or network interface cards should be placed in every
computer
A cable that is called as the Ethernet cable should be connected
with the entire computer used in connection.
Networking hubs that are used to introduce the systems or the
network over network traffic.
Hardware components of Ethernet
6. A hub is a physical-layer device that acts on individual bits rather
than frames.
NIC (Network Interface Card ) has small device called transceiver.
Transceiver = transmitter + receiver
Transceiver checks :-
Nobodies transmitting
One host transmitting
Multiple host have transmitted so there is a collision.
8. Computer A,B and C are connected physically by LAN cable
Suppose A want to send data B a transceiver checks the voltage of
the wire ,if the wire is the wire is free then A will send transmitted
. Suppose at the same time B send data to C there will be collision
every one including A & B is different and randomly selected after
waiting this random time A & B Will retransmit . Is there is
another collision they will increase the waiting time exponentially
this continuous until successful transmission , this algorithm are
called as binary exponential back-of policy the over all Operation
called as carrier sense multiple access with collision detect
(CSMA/CD)
How to work Ethernet ?
9. Ethernet Technologies
Ethernet comes in many different flavors, with somewhat
bewildering acronyms such as 10BASE-T, 10BASE-2, 100BASE-
T, 1000BASE-LX, and10GBASE-T.
These and many other Ethernet technologies have been
standardized
over the years by the IEEE 802.3 CSMA/CD (Ethernet) working
group [IEEE 802.3 2012].
CDMA/CD protocol nicely solves the multiple access problem.
The standard for Gigabit Ethernet, referred to as IEEE 802.3z,
10. Ethernet Frame
A ethernet frame is a physical layer communications transmission,
comprised of 6 fields which are assembled to transmit any higher
layer protocol over an Ethernet fabric.
11. A IEEE 802.3 Ethernet Frame is composed of 6 segments which are
described in detail below:-
Preamble: The preamble is not typically used in modern
ethernet networks as its function is to provide
signal start up time for 10Mbps Ethernet
signals. modern 100Mbps, 1000Mbps or
10Gbps ethernet use constant signalling,
which avoids the need for the preamble.
The preamble, while listed as a part of the
actual Ethernet frame is technically not part
of the frame as it is added to the front of the
frame by the NIC just before the frame is put
on the wire.
Ethernet Frame (Continued)
12. Destination and Source Address:
These two sections of the frame are likely
the most commonly understood in that they
contain the MAC address for the source
“transmitting system” and the destination
“target system”.
Type / Length
The type / length field is used to identify
what higher-level network protocol is being
carried in the frame (example: TCP/IP)
Ethernet Frame(Continued)
13. Data / Payload
The diagram specifies a range between a
minimum of 46 bytes and maximum of 1500
bytes. A standard Ethernet frame has a
maximum payload of 1500 bytes, frames
over 1500 bytes are considered Jumbo
Frames.
Frame Check Sequence (CRC)
The CRC is generated by applying a
polynomial to bits which make up the frame
at transmission. This same polynomial is
used at the receiving station to verify the
contents of the frame have not changed in
Ethernet Frame (Continued)
14. Applications
Layer 2 VPNs for IT Infrastructure: Ethernet Layer 2 Virtual
Private Networks (VPNs) maximize the performance of existing
IT infrastructure increasing network control.
Cloud Computing: The deterministic and dynamic service
attributes of Ethernet benefit the way cloud computing is used and
consumed.
Site to Site Access: Provides added performance and higher
bandwidth levels along with service standardization at all
locations.
15. Applications
Software-as-a-Service (SaaS), Service Oriented Architecture
(SOA): Offers better transparency, standardization at all locations
and easier performance management.
Video Applications: Provides better quality of service (QoS).
Voice: Voice over Internet Protocol (VoIP) is well-known for its
cost-savings. Ethernet provides quality of service (QoS) options
and improved performance management.
16. Applications
Distributed Storage Area Networks: Provides added
performance and higher bandwidth levels.
CCTV: Closed-circuit television (CCTV) – Ethernet connectivity
offers consistent cost and ubiquity enabling improved service
management.
Business Continuity/Disaster Recovery: Ethernet allow business
continuity and disaster recovery networks to optimally perform
with measurable performance and flexible bandwidth levels.
17. Applications
Distributed Imaging: Ethernet delivers the higher bandwidth
required for distributed imaging systems including picture
archiving and communications system (PACS).
18. LIGHT FIDELITY(LI-FI)
Light based Wi-Fi
Light is used instead of radio-waves to transmit
information
Transceiver fitted LED lamps acts like Wi-Fi modems
LED lamps can light a room as well as transmit-receive
information
Provides illumination as well as data communication
19. NEED FOR LI-FI
Radio spectrum is congested,
but the demand for wireless
data doubles each year Issues
regarding radio spectrum,
such as capacity, availability,
efficiency, security are solved
using LIFI.
Speed of data transmission can
be increased.
20. OVERCOMING WIFI ISSUES
CAPACITY
Spectrum is 10,000 times greater than that of radio
frequency
EFFICIENCY
Highly efficient since LED consumes less energy
AVAILABILITY
Light waves available everywhere.
SECURITY
Cannot penetrate through walls. Hence data cannot be
intercepted.
21. VISIBLE LIGHT COMMUNICATION
In electromagnetic spectrum, gamma, UV rays are dangerous
for human body.
IR rays, due to eye safety regulations, are not used
22. LIFE OF LIFI
Introduced by Professor Herald hass, at the university of
Edinburgh.
Established in 2011 TED global talk
The promotion of idea through TED helped to start a company,
Pure Li-Fi
Pure Li-Fi, formerly pure VLC, is an original equipment
manufacture firm setup to commercialize Li-Fi products for
integration with existing LED lighting systems
In October 2011, few companies and industries group formed
Li-Fi consortium to promote the high speed optical wireless
systems
23. HOW IT WORKS?
Operational procedure is very simple.
If LED is ON, digital data „1‟ is transmitted & if LED is
OFF, digital data „0‟ is transmitted.
LEDs varies in intensity so fast that a human eye cannot
detect it.
A controller connected at the back side of these LEDs is
used to code data.
Also called as 5G optical communication.
24. IMPLEMENTATION
All the data from Internet is
streamed into lamp driver.
Data from internet is used to
modulate the intensity of LED
light source.
Thus by fast and subtle
variations of current, optical
output can be made to vary at
extremely high speed.
The photo detector picks up the
signal.
The receiver dongle then
converts the tiny changes in
amplitude into a data stream.
25. LI-FI NETWORKS
Li-Fi connector and router are the main
components for a network
Room connector:
Optical signals cannot penetrate
through walls, in order to provide an
optical WLAN, rooms need to be
connected with each other Li-Fi
room connector is a replicator, which
sends the data stream from one side
of the wall to the other side via an
optical fiber.
For smaller rooms, connector act as
the only Li-Fi hotspot in the room
26. LI-FI ROUTER
Serves as a connector to external link
like DSL.
Covers a radius of about 20 meters
The transmission speed is 100 Mbps.
Suitable for small office or home use
27. APPLICATIONS
Li-Fi can be used in
sensitive areas such as aircrafts for data transmission
without causing interference.
Places where it is difficult to lay optical fibers like
operation theaters Traffic scenarios, thereby reducing
accidents.
Underwater applications where radio waves cannot
propagate.
Industries like petrochemical plants, nuclear power plants
, petrol pumps etc
28. TRAFFIC SCENARIO
In traffic scenario, Li-Fi can be used to
communicate with the LED lights of
cars .
Cars can have LED-based headlights,
backlights and can communicate with
each other.
This might prevent accidents, by
exchanging information, when the
vehicles are too close
Using Li-Fi, Street lights can be used
to send information about the road
condition to the car.
29. LECTURE / SEMINAR HALLS
Downloading notes from blogs of teachers
Often it is necessary to download
lecture notes from the blogs of
respective teachers. With Li-Fi, the
download can be done in the hall itself
Interactive classroom with interconnected devices
The classroom will be more interactive
with the real-time interconnectivity
between 500 devices
Sharing views & queries with the entire class
Each person‟s queries, views and
clarifications can be shared not only
with the teacher, but with the entire
class.
30. INDUSTRIES
Used in RF restricted environments like chemical industries,
nuclear power plants, petrol pumps
31. HOME AND SMALL OFFICES
In home and small offices, Li-Fi can be used to communicate with devices like
Laptops
Internet access
HD video streaming
Printer
32. AIRCRAFTS
The whole airways
communication are performed
on the basis of radio waves.
Hence passengers face the
problem in communication
media.
This problem can be overcome
by using Li-Fi, since light waves
will not interfere with radio
waves.
33. A PROVEN TECHNOLOGY
Harald has demonstrated Li-Fi
using an ordinary table lamp and a
computer located below the lamp.
He successfully transmitted data at
speed exceeding 10Mbps using light
waves from LED light bulbs .
Also he periodically blocked the
beam of light, causing the connection
to drop.
34. VLC SMARTPHONES
The first VLC Smartphone was
presented by Consumer Electronics in
January, 2014
The phone uses Wysips connect – a
clear thin layer of crystal glass is
added to the small screens
Smartphone makes them solar
powered.
Smartphone could get 15% more
battery life in a day Can communicate
using Li-Fi.
35. ADVANTAGES
Data rate greater than 10 Gbps; Theoretically allowing HD
film to be downloaded in 30 seconds Can be used anywhere,
even in RF restricted areas; Since light waves will not interfere
with radio waves.
Mostly LED light bulbs are used, which consumes less energy.
Hence cost efficient.
As light waves cannot penetrate through walls, the data cannot
be intercepted; Thus provides secured communication.
Efficient alternative to radio based wireless; since it is quick
and reliable.
36. LIMITATIONS
Visible light cannot penetrate through solid objects.
A major challenge of Li-Fi is how the receiving device will
transmit back to transmitter.
Interferences from external light sources like sunlight, in the
path of transmission will cause interruption in the
communication.
Data transmission can be easily blocked by any object placed in
front of LED source.
37. CONCLUSION
Thus, if Li-Fi technology can be put into practical use, every
bulb can be used as an alternative to Wi-Fi hotspots. It
provides simple, faster and efficient wireless data
communication.
Li-Fi will make us to proceed towards the cleaner, greener,
safer and brighter future.