Carrier-sense multiple access with collision detection (CSMA/CD) is a media access control method used most notably in early Ethernet technology for local area networking.Carrier-sense multiple access with collision detection is a media access control method used most notably in early Ethernet technology for local area networking. It uses carrier-sensing to defer transmissions until no other stations are transmitting.
The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between adjacent network nodes in a wide area network (WAN) or between nodes on the same local area network (LAN) segment.
In the seven-layer OSI model of computer networking, media access control (MAC) data communication protocol is a sublayer of the data link layer (layer 2). The MAC sublayer provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate within a multiple access network that incorporates a shared medium, e.g. an Ethernet network. The hardware that implements the MAC is referred to as a media access controller.
The MAC sublayer acts as an interface between the logical link control (LLC) sublayer and the network's physical layer. The MAC layer emulates a full-duplex logical communication channel in a multi-point network. This channel may provide unicast, multicast or broadcast communication service.
The data link layer, or layer 2, is the second layer of the seven-layer OSI model of computer networking. This layer is the protocol layer that transfers data between adjacent network nodes in a wide area network (WAN) or between nodes on the same local area network (LAN) segment.
In the seven-layer OSI model of computer networking, media access control (MAC) data communication protocol is a sublayer of the data link layer (layer 2). The MAC sublayer provides addressing and channel access control mechanisms that make it possible for several terminals or network nodes to communicate within a multiple access network that incorporates a shared medium, e.g. an Ethernet network. The hardware that implements the MAC is referred to as a media access controller.
The MAC sublayer acts as an interface between the logical link control (LLC) sublayer and the network's physical layer. The MAC layer emulates a full-duplex logical communication channel in a multi-point network. This channel may provide unicast, multicast or broadcast communication service.
Network layer - design Issues ,Store-and-Forward Packet Switching, Services Provided to the Transport Layer, Which service is the best , Implementation of Service , Implementation of Connectionless Service , Implementation of Connection-Oriented Service
RANDOM ACCESS PROTOCOL IN COMMUNICATION AMOGHA A K
In random access ,each station has right to send the data. However , if more than one station tries to send ,collision will occur .To avoid this collision , protocols came into existence.
In random access method , no stations are superior & none is assigned the control over the other .
When a station has a data to send , it uses a procedure defined by a protocol whether to send or not .
Network layer - design Issues ,Store-and-Forward Packet Switching, Services Provided to the Transport Layer, Which service is the best , Implementation of Service , Implementation of Connectionless Service , Implementation of Connection-Oriented Service
RANDOM ACCESS PROTOCOL IN COMMUNICATION AMOGHA A K
In random access ,each station has right to send the data. However , if more than one station tries to send ,collision will occur .To avoid this collision , protocols came into existence.
In random access method , no stations are superior & none is assigned the control over the other .
When a station has a data to send , it uses a procedure defined by a protocol whether to send or not .
Carrier Sense Multiple Access With Collision Detection (CSMA/CD) Details : Me...Soumen Santra
Media Access Protocol (MAC)
Carrier Sense Multiple Access With Collision Detection (CSMA/CD)
Definition
Introduction
Features
Principle
Flowchart
Collision Mechanism
COLLISION DETECTION METHODS
Slot Time
Non-Persistent CSMA/CD
Efficiency
Advantages
Disadvantages
Detail Discussion with Mathematical Formula
An e-market, or electronic market, is a virtual marketplace where buyers and sellers can engage in transactions through the use of digital platforms, such as websites, mobile apps, or social media. E-markets have become increasingly popular in recent years due to their convenience, accessibility, and global reach.
E-markets differ from traditional markets in several ways:
Global reach: E-markets have a global reach, allowing buyers and sellers to connect from anywhere in the world. This means that businesses can access new markets and reach customers that they may not have been able to reach through traditional channels.
Convenience: E-markets offer a high degree of convenience, allowing customers to shop from the comfort of their homes or on the go using mobile devices. This convenience factor can lead to higher customer satisfaction and loyalty.
Lower overhead costs: E-markets typically have lower overhead costs than traditional markets, as they do not require physical storefronts, inventory storage, or other infrastructure. This can result in lower prices for customers and higher profit margins for businesses.
24/7 availability: E-markets are available 24/7, allowing customers to shop at any time of the day or night. This can be particularly advantageous for businesses that operate in multiple time zones or that cater to customers with varying schedules.
Greater competition: E-markets can be highly competitive, with many businesses vying for the attention and loyalty of customers. This can result in lower prices, higher quality products, and better customer service as businesses compete for market share.
CFD Simulation of By-pass Flow in a HRSG module by R&R Consult.pptxR&R Consult
CFD analysis is incredibly effective at solving mysteries and improving the performance of complex systems!
Here's a great example: At a large natural gas-fired power plant, where they use waste heat to generate steam and energy, they were puzzled that their boiler wasn't producing as much steam as expected.
R&R and Tetra Engineering Group Inc. were asked to solve the issue with reduced steam production.
An inspection had shown that a significant amount of hot flue gas was bypassing the boiler tubes, where the heat was supposed to be transferred.
R&R Consult conducted a CFD analysis, which revealed that 6.3% of the flue gas was bypassing the boiler tubes without transferring heat. The analysis also showed that the flue gas was instead being directed along the sides of the boiler and between the modules that were supposed to capture the heat. This was the cause of the reduced performance.
Based on our results, Tetra Engineering installed covering plates to reduce the bypass flow. This improved the boiler's performance and increased electricity production.
It is always satisfying when we can help solve complex challenges like this. Do your systems also need a check-up or optimization? Give us a call!
Work done in cooperation with James Malloy and David Moelling from Tetra Engineering.
More examples of our work https://www.r-r-consult.dk/en/cases-en/
Hybrid optimization of pumped hydro system and solar- Engr. Abdul-Azeez.pdffxintegritypublishin
Advancements in technology unveil a myriad of electrical and electronic breakthroughs geared towards efficiently harnessing limited resources to meet human energy demands. The optimization of hybrid solar PV panels and pumped hydro energy supply systems plays a pivotal role in utilizing natural resources effectively. This initiative not only benefits humanity but also fosters environmental sustainability. The study investigated the design optimization of these hybrid systems, focusing on understanding solar radiation patterns, identifying geographical influences on solar radiation, formulating a mathematical model for system optimization, and determining the optimal configuration of PV panels and pumped hydro storage. Through a comparative analysis approach and eight weeks of data collection, the study addressed key research questions related to solar radiation patterns and optimal system design. The findings highlighted regions with heightened solar radiation levels, showcasing substantial potential for power generation and emphasizing the system's efficiency. Optimizing system design significantly boosted power generation, promoted renewable energy utilization, and enhanced energy storage capacity. The study underscored the benefits of optimizing hybrid solar PV panels and pumped hydro energy supply systems for sustainable energy usage. Optimizing the design of solar PV panels and pumped hydro energy supply systems as examined across diverse climatic conditions in a developing country, not only enhances power generation but also improves the integration of renewable energy sources and boosts energy storage capacities, particularly beneficial for less economically prosperous regions. Additionally, the study provides valuable insights for advancing energy research in economically viable areas. Recommendations included conducting site-specific assessments, utilizing advanced modeling tools, implementing regular maintenance protocols, and enhancing communication among system components.
Explore the innovative world of trenchless pipe repair with our comprehensive guide, "The Benefits and Techniques of Trenchless Pipe Repair." This document delves into the modern methods of repairing underground pipes without the need for extensive excavation, highlighting the numerous advantages and the latest techniques used in the industry.
Learn about the cost savings, reduced environmental impact, and minimal disruption associated with trenchless technology. Discover detailed explanations of popular techniques such as pipe bursting, cured-in-place pipe (CIPP) lining, and directional drilling. Understand how these methods can be applied to various types of infrastructure, from residential plumbing to large-scale municipal systems.
Ideal for homeowners, contractors, engineers, and anyone interested in modern plumbing solutions, this guide provides valuable insights into why trenchless pipe repair is becoming the preferred choice for pipe rehabilitation. Stay informed about the latest advancements and best practices in the field.
Final project report on grocery store management system..pdfKamal Acharya
In today’s fast-changing business environment, it’s extremely important to be able to respond to client needs in the most effective and timely manner. If your customers wish to see your business online and have instant access to your products or services.
Online Grocery Store is an e-commerce website, which retails various grocery products. This project allows viewing various products available enables registered users to purchase desired products instantly using Paytm, UPI payment processor (Instant Pay) and also can place order by using Cash on Delivery (Pay Later) option. This project provides an easy access to Administrators and Managers to view orders placed using Pay Later and Instant Pay options.
In order to develop an e-commerce website, a number of Technologies must be studied and understood. These include multi-tiered architecture, server and client-side scripting techniques, implementation technologies, programming language (such as PHP, HTML, CSS, JavaScript) and MySQL relational databases. This is a project with the objective to develop a basic website where a consumer is provided with a shopping cart website and also to know about the technologies used to develop such a website.
This document will discuss each of the underlying technologies to create and implement an e- commerce website.
Saudi Arabia stands as a titan in the global energy landscape, renowned for its abundant oil and gas resources. It's the largest exporter of petroleum and holds some of the world's most significant reserves. Let's delve into the top 10 oil and gas projects shaping Saudi Arabia's energy future in 2024.
Immunizing Image Classifiers Against Localized Adversary Attacksgerogepatton
This paper addresses the vulnerability of deep learning models, particularly convolutional neural networks
(CNN)s, to adversarial attacks and presents a proactive training technique designed to counter them. We
introduce a novel volumization algorithm, which transforms 2D images into 3D volumetric representations.
When combined with 3D convolution and deep curriculum learning optimization (CLO), itsignificantly improves
the immunity of models against localized universal attacks by up to 40%. We evaluate our proposed approach
using contemporary CNN architectures and the modified Canadian Institute for Advanced Research (CIFAR-10
and CIFAR-100) and ImageNet Large Scale Visual Recognition Challenge (ILSVRC12) datasets, showcasing
accuracy improvements over previous techniques. The results indicate that the combination of the volumetric
input and curriculum learning holds significant promise for mitigating adversarial attacks without necessitating
adversary training.
Hierarchical Digital Twin of a Naval Power SystemKerry Sado
A hierarchical digital twin of a Naval DC power system has been developed and experimentally verified. Similar to other state-of-the-art digital twins, this technology creates a digital replica of the physical system executed in real-time or faster, which can modify hardware controls. However, its advantage stems from distributing computational efforts by utilizing a hierarchical structure composed of lower-level digital twin blocks and a higher-level system digital twin. Each digital twin block is associated with a physical subsystem of the hardware and communicates with a singular system digital twin, which creates a system-level response. By extracting information from each level of the hierarchy, power system controls of the hardware were reconfigured autonomously. This hierarchical digital twin development offers several advantages over other digital twins, particularly in the field of naval power systems. The hierarchical structure allows for greater computational efficiency and scalability while the ability to autonomously reconfigure hardware controls offers increased flexibility and responsiveness. The hierarchical decomposition and models utilized were well aligned with the physical twin, as indicated by the maximum deviations between the developed digital twin hierarchy and the hardware.
Overview of the fundamental roles in Hydropower generation and the components involved in wider Electrical Engineering.
This paper presents the design and construction of hydroelectric dams from the hydrologist’s survey of the valley before construction, all aspects and involved disciplines, fluid dynamics, structural engineering, generation and mains frequency regulation to the very transmission of power through the network in the United Kingdom.
Author: Robbie Edward Sayers
Collaborators and co editors: Charlie Sims and Connor Healey.
(C) 2024 Robbie E. Sayers
Governing Equations for Fundamental Aerodynamics_Anderson2010.pdf
CSMA /CD PPT ON SLIDESHARE
1.
2.
3.
4.
5. CSMA/CD protocol can be considered as a refinement
and modification of pure "Carrier Sense Multiple
Access" (CSMA).
In a CSMA system, the chance of collision can be
reduced if a station senses the medium before trying
to use it , but it can not eliminate it.
CSMA/CD is used to improve CSMA performance
and it augments the algorithm to handle the collision.
6. • CARRIER SENSE MULTIPLE ACCESS with
COLLISION DETECTION (CSMA/CD) is
a MEDIA ACCESS CONTROL method used most
notably in early ETHERNET technology for LOCAL
AREA NETWORKING .
• This is used in combination with COLLISION
DETECTION in which a transmitting station detects
collisions by sensing transmissions from other
stations while it is transmitting a frame.
• When this collision condition is detected, the station
stops transmitting that frame, transmits a jam
signal, and then waits for a random time interval
before trying to resend the frame.
7. In CSMA/CD method, a station MONITORS the
MEDIUM after it sends a frame to see if the
transmission was successful. If so, the station is
finished. If however, there is a Collision , the
frame is sent again.
8. • TRANSMIT,
• Otherwise step 2
1.
If Medium
IDLE
• WAIT until idle,
• Then, TRANSMISSION with p=1
2.
If Medium
BUSY
• Transmit brief “JAMMING SIGNAL”
• ABORT Transmission
3.
If Collision
DETECTED
After Aborting- WAIT RANDOM Time, Try again
11. Use one of the “PERSISTENT METHOD” as-
Constantly monitor in order to detect one of two conditions:
Sending of a short “JAMMING SIGNAL” that enforces
the collision in case other stations have not yet sensed the
collision.
Non-Persistent
1-Persistent
P-Persistent
Proceed
according to the
conditions.
What should a
station do if the
channel is busy or
idle?
Transmission is
Finished or
A Collision is
detected.
14. Level of Energy in a Channel can have three values :
• ZERO : Channel is Idle.
• NORMAL: A station has successfully captured the channel &
is sending its frame.
• ABNORMAL : There is a collision & the level of energy is
twice the normal level.
15. • CSMA/CD can be in one of Three States :
Contention
Transmission
Idle
States are
observed during
the transmission
of frames.
16. • The CSMA method does not tells us what to do in case
there is a collision.
17. Time to detect
collision <
2*maximum
propagation
delay.
Minimum
frame size
enough to
allow collision
detection prior
to end of
transmission.
The reaction
time in CSMA-
CD is 2tprop.
18. * The Throughput of
CSMA/CD is greater than that
of Pure or Slotted ALOHA.
* For 1-persistent method the
maximum throughput is around
50 % when G=1.
* For Non-persistent method, the
maximum throughput can go up to
90 % when G is between 3 and 8.
19. RELIABLE; Collisions are detected and
packets are , so no data is lost.
Relatively FAST; A computer does not
have to wait its "turn" to transmit data.
EFFECTIVE; handle data collisions.
20. LIMITED to 2500 meters/11/2
mile; The collision detection
mechanism restricts the length of
cable segment that can be used.
Inappropriate for LARGE/active
networks; The slowdown increases,
as the network grows larger.
