The document discusses various data link layer protocols. It begins by explaining the position and functions of the data link layer, including providing an interface to the network layer, dealing with transmission errors, regulating data flow, and preventing fast senders from overwhelming slow receivers. It then discusses various data link layer design issues like framing, error control, flow control, and the services provided to the network layer. The document proceeds to explain different elementary data link protocols like unrestricted simplex, stop-and-wait, and simplex protocols for noisy channels. It concludes by describing sliding window protocols including one-bit, go-back-N, and selective repeat protocols.
The document provides information about various data link layer concepts including:
1. The data link layer provides framing, flow control, and error control between network layers on different machines. It uses devices like switches and bridges.
2. Error detection methods include parity checks, checksums, and CRC to detect errors in transmitted frames.
3. Data link protocols for flow control include stop-and-wait, sliding window protocols, and ARQ methods like go-back-N and selective repeat.
4. Framing encapsulates data with headers and trailers using fixed or variable size frames. Methods like byte stuffing and bit stuffing handle special characters in the data.
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.
Jaimin chp-3 - data-link layer- 2011 batchJaimin Jani
The document discusses data link layer services and functions including:
1. Providing interfaces between network layers and framing/error control/flow control.
2. Types of services include unacknowledged/acknowledged connectionless and connection-oriented.
3. Framing methods like character count, flag bytes, and encoding violations are used to delineate frames. Error control uses acknowledgments, timers, and sequence numbers.
This document outlines the syllabus for a course on computer networks. It covers three units: introduction to networking concepts and reference models, the data link layer, and the network layer. The data link layer section describes its design issues, functions, services, framing, error control, and flow control. It also discusses error detection techniques like vertical redundancy checks, longitudinal redundancy checks, cyclic redundancy checks, and checksums. The document provides examples and diagrams to explain these concepts.
The document summarizes key concepts relating to the data link layer, including:
1) The data link layer provides services to the network layer such as framing data and error control. It regulates data flow and deals with transmission errors.
2) Framing involves delimiting frames with flags or escape sequences to handle bit stuffing. Error detection uses techniques like CRC checksums while error correction uses codes like Hamming codes.
3) Stop-and-wait protocols were improved with sliding window protocols using sequence numbers and acknowledgments to allow pipelining and handle lost frames more efficiently through techniques like selective repeat.
The document describes various error detection codes including parity, checksums, and cyclic redundancy checks (CRCs). Parity bits detect single bit errors by making the total number of 1s in a data block even or odd. Checksums compute a sum of data bits to detect errors. CRCs treat data as polynomial coefficients, computing a checksum as the remainder of a polynomial division to detect all errors up to the checksum size. The document also discusses how these codes are implemented in communication protocols.
The document discusses several key topics in data link layer design including framing, error detection and correction, and flow control. It describes different framing techniques like character counting, stuffing, and physical layer coding violations. It also explains various error detection methods like parity checks, cyclic redundancy checks (CRC), and Hamming codes. Flow control mechanisms like sliding window protocols are also mentioned. Examples are provided to illustrate Hamming codes and CRC calculations.
The document provides information about various data link layer concepts including:
1. The data link layer provides framing, flow control, and error control between network layers on different machines. It uses devices like switches and bridges.
2. Error detection methods include parity checks, checksums, and CRC to detect errors in transmitted frames.
3. Data link protocols for flow control include stop-and-wait, sliding window protocols, and ARQ methods like go-back-N and selective repeat.
4. Framing encapsulates data with headers and trailers using fixed or variable size frames. Methods like byte stuffing and bit stuffing handle special characters in the data.
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.
Jaimin chp-3 - data-link layer- 2011 batchJaimin Jani
The document discusses data link layer services and functions including:
1. Providing interfaces between network layers and framing/error control/flow control.
2. Types of services include unacknowledged/acknowledged connectionless and connection-oriented.
3. Framing methods like character count, flag bytes, and encoding violations are used to delineate frames. Error control uses acknowledgments, timers, and sequence numbers.
This document outlines the syllabus for a course on computer networks. It covers three units: introduction to networking concepts and reference models, the data link layer, and the network layer. The data link layer section describes its design issues, functions, services, framing, error control, and flow control. It also discusses error detection techniques like vertical redundancy checks, longitudinal redundancy checks, cyclic redundancy checks, and checksums. The document provides examples and diagrams to explain these concepts.
The document summarizes key concepts relating to the data link layer, including:
1) The data link layer provides services to the network layer such as framing data and error control. It regulates data flow and deals with transmission errors.
2) Framing involves delimiting frames with flags or escape sequences to handle bit stuffing. Error detection uses techniques like CRC checksums while error correction uses codes like Hamming codes.
3) Stop-and-wait protocols were improved with sliding window protocols using sequence numbers and acknowledgments to allow pipelining and handle lost frames more efficiently through techniques like selective repeat.
The document describes various error detection codes including parity, checksums, and cyclic redundancy checks (CRCs). Parity bits detect single bit errors by making the total number of 1s in a data block even or odd. Checksums compute a sum of data bits to detect errors. CRCs treat data as polynomial coefficients, computing a checksum as the remainder of a polynomial division to detect all errors up to the checksum size. The document also discusses how these codes are implemented in communication protocols.
The document discusses several key topics in data link layer design including framing, error detection and correction, and flow control. It describes different framing techniques like character counting, stuffing, and physical layer coding violations. It also explains various error detection methods like parity checks, cyclic redundancy checks (CRC), and Hamming codes. Flow control mechanisms like sliding window protocols are also mentioned. Examples are provided to illustrate Hamming codes and CRC calculations.
The document summarizes key concepts about the data link layer, including the services it provides to the network layer, such as error control and flow control. It describes functions of the data link layer like framing, error detection, and flow control. It also covers different data link protocols, such as HDLC, PPP, and protocols used in the Internet. Specific topics discussed include error correcting codes, sliding window protocols, finite state machine models, and Petri net models for analyzing protocols.
The document discusses several techniques for error detection in digital communications, including block coding, parity checking, cyclic redundancy checks (CRC), and Hamming codes. Block coding involves dividing a message into blocks of k bits and adding r redundant bits to each block. Parity checking adds an extra bit to detect errors by checking if the number of 1's is even or odd. CRC generates a frame check sequence such that the data block and sequence are divisible by a predetermined number to detect errors. Hamming codes add k parity bits to an n-bit data word to detect and sometimes correct errors. These techniques help detect errors caused by interference during transmission but cannot always determine the location or correct multiple errors.
The document discusses the functions of the data link layer, including framing data, error detection and correction, and flow control. Specifically, it describes how the data link layer:
1. Organizes the physical layer bit stream into frames and applies error detection techniques like checksums.
2. Uses flow control methods like acknowledgments and windowing to prevent fast senders from overwhelming slow receivers and ensure reliable transmission.
3. Provides an interface between the physical layer and network layer, allowing network layer packets to be reliably transmitted over a communication channel.
The data link layer transforms the physical layer into a link responsible for node-to-node communication. It provides framing, addressing, error control, and flow control. Specific responsibilities include grouping bits into frames, adding addressing and error detection through checksums, and preventing fast senders from overwhelming slow receivers through flow control. Data link protocols must provide well-defined interfaces, handle transmission errors, and regulate data flow. They offer services like unacknowledged connectionless, acknowledged connectionless, and acknowledged connection-oriented to transfer data reliably between nodes.
U2CH1Data Link Layerxxxxxxxxxxxxxxxxx.pptxk2w9psdb96
1. The data link layer transforms the physical layer into a link responsible for node-to-node communication. It provides framing, addressing, error control, flow control, and media access control.
2. Error control uses acknowledgements, timers, and sequence numbers to ensure reliable delivery of frames. Framing groups bits into frames using techniques like bit stuffing. Flow control regulates data flow between sender and receiver.
3. Cyclic redundancy checks (CRCs) are commonly used for error detection. A CRC calculates a checksum by dividing the data by a fixed generator polynomial, allowing errors to be detected on receipt.
The document discusses various aspects of data link layer protocols. It describes the services provided by the data link layer, including framing, error control, and flow control. It then discusses different types of framing, error detection techniques like CRC codes, and elementary data link protocols including stop-and-wait and sliding window protocols. It also covers topics like pipelining, error recovery methods for noisy channels, and the use of finite state machines to model protocols.
The document provides an overview of the data link layer (DLL). It discusses how the DLL transforms the physical layer into a link responsible for node-to-node communication. The DLL is responsible for framing, addressing, flow control, error control, and media access control. It provides services like transferring data packets between network layers on different machines with options for unacknowledged connectionless, acknowledged connectionless, and acknowledged connection-oriented services. Key DLL functions include framing data into frames, error control using acknowledgements and retransmissions, and flow control to regulate data transmission rates.
The document discusses the data link layer of the OSI model. It describes the data link layer as the second layer that is responsible for framing data, error detection and correction, and flow control between nodes on a network. The data link layer has two sublayers - the logical link control layer deals with protocols, flow control and error control, while the media access control layer controls access to the shared media. The data link layer frames data from the network layer, provides addressing, synchronization, error detection using parity checks and CRC, error correction using ACKs and retransmissions, and flow control using stop-and-wait or sliding window protocols.
The document discusses various functions and protocols of the data link layer, including:
1. Framing of data, error detection using checksums, and flow control to prevent faster senders from overwhelming slower receivers.
2. Common data link layer protocols like stop-and-wait and sliding window protocols using go-back-N and selective repeat to allow multiple frames to be transmitted.
3. Error detection techniques like parity bits, checksums, and cyclic redundancy checks to detect errors in transmitted frames.
The document discusses various functions and protocols of the data link layer, including:
1. Framing of data, error detection using checksums, and flow control to prevent faster senders from overwhelming slower receivers.
2. Common data link layer protocols like stop-and-wait and sliding window protocols using go-back-N and selective repeat to allow multiple frames to be transmitted.
3. Error detection techniques like parity bits, checksums, and cyclic redundancy checks to detect errors in transmitted frames.
The document discusses the data link layer and its responsibilities. Specifically:
1) The data link layer transforms the physical layer into a link responsible for node-to-node communication. It is responsible for framing, addressing, flow control, error control, and media access control.
2) It provides services to the network layer like transferring data packets between network layers on different machines and offering various service models like unacknowledged connectionless, acknowledged connectionless, and acknowledged connection-oriented.
3) Key data link layer protocols are discussed including framing, error detection using CRC, flow control, and elementary protocol examples like unrestricted simplex and stop-and-wait.
The document provides an overview of the data link layer. It discusses how the data link layer transforms the physical layer into a link responsible for node-to-node communication. Specific responsibilities include framing, addressing, flow control, error control, and media access control. It then describes various data link layer services, design issues, error detection and correction techniques like parity checks, cyclic redundancy checks, and flow control mechanisms.
Error coding uses mathematical formulas to encode data bits into longer code words for transmission. This allows errors caused by environmental interference to be detected and sometimes corrected at the destination. There are two main types of error coding: error-detecting codes and error-correcting codes. Error-detecting codes add enough redundancy to allow errors to be detected but not corrected, while error-correcting codes add more redundancy to allow errors to be corrected. Common error-detecting coding techniques include parity checks, checksums, and cyclic redundancy checks (CRCs). These techniques use additional redundant bits appended to the data to facilitate error detection. CRC is particularly powerful as it can detect all single-bit errors and many burst errors.
The document discusses various functions and design issues related to the data link layer, including:
1. The data link layer provides services like framing, error control, and flow control to regulate data transmission between network layers.
2. Functions of the data link layer include providing an interface to the network layer, dealing with transmission errors, and regulating data flow to prevent fast senders from swamping slow receivers.
3. The document discusses various data link layer techniques for framing, error detection, error correction, and flow control including bit stuffing, parity schemes, CRC schemes, and error-correcting codes.
This document summarizes a faculty development program on computer networks held from April 24-30, 2019. On April 25, Dr. A. Kathirvel from MNM Jain Engineering College gave a lecture covering various topics related to the data link layer, including data link protocols, media access control, encoding, framing, and error detection techniques. Specific protocols and concepts discussed include HDLC, PPP, Manchester encoding, 4B/5B encoding, byte-oriented and bit-oriented framing, CRC, checksums, and two-dimensional parity.
This document provides an overview of error detection and correction techniques used in digital communication systems. It defines different types of errors like single bit errors and burst errors that can occur during signal transmission. It also describes various error detection methods like parity checking, checksum detection, and cyclic redundancy check (CRC). The document explains concepts of forward error correction (FEC), automatic repeat request (ARQ), and CRC checkers. It provides block diagrams of the basic ARQ system and its operations.
computer Networks Error Detection and Correction.pptJayaprasanna4
This document discusses error detection and correction in data transmission. It covers the following key points:
- There are two main types of errors: single-bit errors and burst errors. Burst errors are more common in serial transmission.
- Error detection verifies data accuracy without having the original message. It uses redundancy like vertical and longitudinal redundancy checks. Cyclic redundancy checks use polynomial division to detect errors.
- Error correction automatically fixes certain errors. Single-bit error correction reverses the value of the altered bit. Hamming codes use additional redundant bits to detect and correct single-bit errors.
The document summarizes key concepts about the data link layer, including the services it provides to the network layer, such as error control and flow control. It describes functions of the data link layer like framing, error detection, and flow control. It also covers different data link protocols, such as HDLC, PPP, and protocols used in the Internet. Specific topics discussed include error correcting codes, sliding window protocols, finite state machine models, and Petri net models for analyzing protocols.
The document discusses several techniques for error detection in digital communications, including block coding, parity checking, cyclic redundancy checks (CRC), and Hamming codes. Block coding involves dividing a message into blocks of k bits and adding r redundant bits to each block. Parity checking adds an extra bit to detect errors by checking if the number of 1's is even or odd. CRC generates a frame check sequence such that the data block and sequence are divisible by a predetermined number to detect errors. Hamming codes add k parity bits to an n-bit data word to detect and sometimes correct errors. These techniques help detect errors caused by interference during transmission but cannot always determine the location or correct multiple errors.
The document discusses the functions of the data link layer, including framing data, error detection and correction, and flow control. Specifically, it describes how the data link layer:
1. Organizes the physical layer bit stream into frames and applies error detection techniques like checksums.
2. Uses flow control methods like acknowledgments and windowing to prevent fast senders from overwhelming slow receivers and ensure reliable transmission.
3. Provides an interface between the physical layer and network layer, allowing network layer packets to be reliably transmitted over a communication channel.
The data link layer transforms the physical layer into a link responsible for node-to-node communication. It provides framing, addressing, error control, and flow control. Specific responsibilities include grouping bits into frames, adding addressing and error detection through checksums, and preventing fast senders from overwhelming slow receivers through flow control. Data link protocols must provide well-defined interfaces, handle transmission errors, and regulate data flow. They offer services like unacknowledged connectionless, acknowledged connectionless, and acknowledged connection-oriented to transfer data reliably between nodes.
U2CH1Data Link Layerxxxxxxxxxxxxxxxxx.pptxk2w9psdb96
1. The data link layer transforms the physical layer into a link responsible for node-to-node communication. It provides framing, addressing, error control, flow control, and media access control.
2. Error control uses acknowledgements, timers, and sequence numbers to ensure reliable delivery of frames. Framing groups bits into frames using techniques like bit stuffing. Flow control regulates data flow between sender and receiver.
3. Cyclic redundancy checks (CRCs) are commonly used for error detection. A CRC calculates a checksum by dividing the data by a fixed generator polynomial, allowing errors to be detected on receipt.
The document discusses various aspects of data link layer protocols. It describes the services provided by the data link layer, including framing, error control, and flow control. It then discusses different types of framing, error detection techniques like CRC codes, and elementary data link protocols including stop-and-wait and sliding window protocols. It also covers topics like pipelining, error recovery methods for noisy channels, and the use of finite state machines to model protocols.
The document provides an overview of the data link layer (DLL). It discusses how the DLL transforms the physical layer into a link responsible for node-to-node communication. The DLL is responsible for framing, addressing, flow control, error control, and media access control. It provides services like transferring data packets between network layers on different machines with options for unacknowledged connectionless, acknowledged connectionless, and acknowledged connection-oriented services. Key DLL functions include framing data into frames, error control using acknowledgements and retransmissions, and flow control to regulate data transmission rates.
The document discusses the data link layer of the OSI model. It describes the data link layer as the second layer that is responsible for framing data, error detection and correction, and flow control between nodes on a network. The data link layer has two sublayers - the logical link control layer deals with protocols, flow control and error control, while the media access control layer controls access to the shared media. The data link layer frames data from the network layer, provides addressing, synchronization, error detection using parity checks and CRC, error correction using ACKs and retransmissions, and flow control using stop-and-wait or sliding window protocols.
The document discusses various functions and protocols of the data link layer, including:
1. Framing of data, error detection using checksums, and flow control to prevent faster senders from overwhelming slower receivers.
2. Common data link layer protocols like stop-and-wait and sliding window protocols using go-back-N and selective repeat to allow multiple frames to be transmitted.
3. Error detection techniques like parity bits, checksums, and cyclic redundancy checks to detect errors in transmitted frames.
The document discusses various functions and protocols of the data link layer, including:
1. Framing of data, error detection using checksums, and flow control to prevent faster senders from overwhelming slower receivers.
2. Common data link layer protocols like stop-and-wait and sliding window protocols using go-back-N and selective repeat to allow multiple frames to be transmitted.
3. Error detection techniques like parity bits, checksums, and cyclic redundancy checks to detect errors in transmitted frames.
The document discusses the data link layer and its responsibilities. Specifically:
1) The data link layer transforms the physical layer into a link responsible for node-to-node communication. It is responsible for framing, addressing, flow control, error control, and media access control.
2) It provides services to the network layer like transferring data packets between network layers on different machines and offering various service models like unacknowledged connectionless, acknowledged connectionless, and acknowledged connection-oriented.
3) Key data link layer protocols are discussed including framing, error detection using CRC, flow control, and elementary protocol examples like unrestricted simplex and stop-and-wait.
The document provides an overview of the data link layer. It discusses how the data link layer transforms the physical layer into a link responsible for node-to-node communication. Specific responsibilities include framing, addressing, flow control, error control, and media access control. It then describes various data link layer services, design issues, error detection and correction techniques like parity checks, cyclic redundancy checks, and flow control mechanisms.
Error coding uses mathematical formulas to encode data bits into longer code words for transmission. This allows errors caused by environmental interference to be detected and sometimes corrected at the destination. There are two main types of error coding: error-detecting codes and error-correcting codes. Error-detecting codes add enough redundancy to allow errors to be detected but not corrected, while error-correcting codes add more redundancy to allow errors to be corrected. Common error-detecting coding techniques include parity checks, checksums, and cyclic redundancy checks (CRCs). These techniques use additional redundant bits appended to the data to facilitate error detection. CRC is particularly powerful as it can detect all single-bit errors and many burst errors.
The document discusses various functions and design issues related to the data link layer, including:
1. The data link layer provides services like framing, error control, and flow control to regulate data transmission between network layers.
2. Functions of the data link layer include providing an interface to the network layer, dealing with transmission errors, and regulating data flow to prevent fast senders from swamping slow receivers.
3. The document discusses various data link layer techniques for framing, error detection, error correction, and flow control including bit stuffing, parity schemes, CRC schemes, and error-correcting codes.
This document summarizes a faculty development program on computer networks held from April 24-30, 2019. On April 25, Dr. A. Kathirvel from MNM Jain Engineering College gave a lecture covering various topics related to the data link layer, including data link protocols, media access control, encoding, framing, and error detection techniques. Specific protocols and concepts discussed include HDLC, PPP, Manchester encoding, 4B/5B encoding, byte-oriented and bit-oriented framing, CRC, checksums, and two-dimensional parity.
This document provides an overview of error detection and correction techniques used in digital communication systems. It defines different types of errors like single bit errors and burst errors that can occur during signal transmission. It also describes various error detection methods like parity checking, checksum detection, and cyclic redundancy check (CRC). The document explains concepts of forward error correction (FEC), automatic repeat request (ARQ), and CRC checkers. It provides block diagrams of the basic ARQ system and its operations.
computer Networks Error Detection and Correction.pptJayaprasanna4
This document discusses error detection and correction in data transmission. It covers the following key points:
- There are two main types of errors: single-bit errors and burst errors. Burst errors are more common in serial transmission.
- Error detection verifies data accuracy without having the original message. It uses redundancy like vertical and longitudinal redundancy checks. Cyclic redundancy checks use polynomial division to detect errors.
- Error correction automatically fixes certain errors. Single-bit error correction reverses the value of the altered bit. Hamming codes use additional redundant bits to detect and correct single-bit errors.
Electric vehicle and photovoltaic advanced roles in enhancing the financial p...IJECEIAES
Climate change's impact on the planet forced the United Nations and governments to promote green energies and electric transportation. The deployments of photovoltaic (PV) and electric vehicle (EV) systems gained stronger momentum due to their numerous advantages over fossil fuel types. The advantages go beyond sustainability to reach financial support and stability. The work in this paper introduces the hybrid system between PV and EV to support industrial and commercial plants. This paper covers the theoretical framework of the proposed hybrid system including the required equation to complete the cost analysis when PV and EV are present. In addition, the proposed design diagram which sets the priorities and requirements of the system is presented. The proposed approach allows setup to advance their power stability, especially during power outages. The presented information supports researchers and plant owners to complete the necessary analysis while promoting the deployment of clean energy. The result of a case study that represents a dairy milk farmer supports the theoretical works and highlights its advanced benefits to existing plants. The short return on investment of the proposed approach supports the paper's novelty approach for the sustainable electrical system. In addition, the proposed system allows for an isolated power setup without the need for a transmission line which enhances the safety of the electrical network
Optimizing Gradle Builds - Gradle DPE Tour Berlin 2024Sinan KOZAK
Sinan from the Delivery Hero mobile infrastructure engineering team shares a deep dive into performance acceleration with Gradle build cache optimizations. Sinan shares their journey into solving complex build-cache problems that affect Gradle builds. By understanding the challenges and solutions found in our journey, we aim to demonstrate the possibilities for faster builds. The case study reveals how overlapping outputs and cache misconfigurations led to significant increases in build times, especially as the project scaled up with numerous modules using Paparazzi tests. The journey from diagnosing to defeating cache issues offers invaluable lessons on maintaining cache integrity without sacrificing functionality.
Discover the latest insights on Data Driven Maintenance with our comprehensive webinar presentation. Learn about traditional maintenance challenges, the right approach to utilizing data, and the benefits of adopting a Data Driven Maintenance strategy. Explore real-world examples, industry best practices, and innovative solutions like FMECA and the D3M model. This presentation, led by expert Jules Oudmans, is essential for asset owners looking to optimize their maintenance processes and leverage digital technologies for improved efficiency and performance. Download now to stay ahead in the evolving maintenance landscape.
Comparative analysis between traditional aquaponics and reconstructed aquapon...bijceesjournal
The aquaponic system of planting is a method that does not require soil usage. It is a method that only needs water, fish, lava rocks (a substitute for soil), and plants. Aquaponic systems are sustainable and environmentally friendly. Its use not only helps to plant in small spaces but also helps reduce artificial chemical use and minimizes excess water use, as aquaponics consumes 90% less water than soil-based gardening. The study applied a descriptive and experimental design to assess and compare conventional and reconstructed aquaponic methods for reproducing tomatoes. The researchers created an observation checklist to determine the significant factors of the study. The study aims to determine the significant difference between traditional aquaponics and reconstructed aquaponics systems propagating tomatoes in terms of height, weight, girth, and number of fruits. The reconstructed aquaponics system’s higher growth yield results in a much more nourished crop than the traditional aquaponics system. It is superior in its number of fruits, height, weight, and girth measurement. Moreover, the reconstructed aquaponics system is proven to eliminate all the hindrances present in the traditional aquaponics system, which are overcrowding of fish, algae growth, pest problems, contaminated water, and dead fish.
Introduction- e - waste – definition - sources of e-waste– hazardous substances in e-waste - effects of e-waste on environment and human health- need for e-waste management– e-waste handling rules - waste minimization techniques for managing e-waste – recycling of e-waste - disposal treatment methods of e- waste – mechanism of extraction of precious metal from leaching solution-global Scenario of E-waste – E-waste in India- case studies.
Software Engineering and Project Management - Introduction, Modeling Concepts...Prakhyath Rai
Introduction, Modeling Concepts and Class Modeling: What is Object orientation? What is OO development? OO Themes; Evidence for usefulness of OO development; OO modeling history. Modeling
as Design technique: Modeling, abstraction, The Three models. Class Modeling: Object and Class Concept, Link and associations concepts, Generalization and Inheritance, A sample class model, Navigation of class models, and UML diagrams
Building the Analysis Models: Requirement Analysis, Analysis Model Approaches, Data modeling Concepts, Object Oriented Analysis, Scenario-Based Modeling, Flow-Oriented Modeling, class Based Modeling, Creating a Behavioral Model.
Batteries -Introduction – Types of Batteries – discharging and charging of battery - characteristics of battery –battery rating- various tests on battery- – Primary battery: silver button cell- Secondary battery :Ni-Cd battery-modern battery: lithium ion battery-maintenance of batteries-choices of batteries for electric vehicle applications.
Fuel Cells: Introduction- importance and classification of fuel cells - description, principle, components, applications of fuel cells: H2-O2 fuel cell, alkaline fuel cell, molten carbonate fuel cell and direct methanol fuel cells.
Embedded machine learning-based road conditions and driving behavior monitoringIJECEIAES
Car accident rates have increased in recent years, resulting in losses in human lives, properties, and other financial costs. An embedded machine learning-based system is developed to address this critical issue. The system can monitor road conditions, detect driving patterns, and identify aggressive driving behaviors. The system is based on neural networks trained on a comprehensive dataset of driving events, driving styles, and road conditions. The system effectively detects potential risks and helps mitigate the frequency and impact of accidents. The primary goal is to ensure the safety of drivers and vehicles. Collecting data involved gathering information on three key road events: normal street and normal drive, speed bumps, circular yellow speed bumps, and three aggressive driving actions: sudden start, sudden stop, and sudden entry. The gathered data is processed and analyzed using a machine learning system designed for limited power and memory devices. The developed system resulted in 91.9% accuracy, 93.6% precision, and 92% recall. The achieved inference time on an Arduino Nano 33 BLE Sense with a 32-bit CPU running at 64 MHz is 34 ms and requires 2.6 kB peak RAM and 139.9 kB program flash memory, making it suitable for resource-constrained embedded systems.
CHINA’S GEO-ECONOMIC OUTREACH IN CENTRAL ASIAN COUNTRIES AND FUTURE PROSPECTjpsjournal1
The rivalry between prominent international actors for dominance over Central Asia's hydrocarbon
reserves and the ancient silk trade route, along with China's diplomatic endeavours in the area, has been
referred to as the "New Great Game." This research centres on the power struggle, considering
geopolitical, geostrategic, and geoeconomic variables. Topics including trade, political hegemony, oil
politics, and conventional and nontraditional security are all explored and explained by the researcher.
Using Mackinder's Heartland, Spykman Rimland, and Hegemonic Stability theories, examines China's role
in Central Asia. This study adheres to the empirical epistemological method and has taken care of
objectivity. This study analyze primary and secondary research documents critically to elaborate role of
china’s geo economic outreach in central Asian countries and its future prospect. China is thriving in trade,
pipeline politics, and winning states, according to this study, thanks to important instruments like the
Shanghai Cooperation Organisation and the Belt and Road Economic Initiative. According to this study,
China is seeing significant success in commerce, pipeline politics, and gaining influence on other
governments. This success may be attributed to the effective utilisation of key tools such as the Shanghai
Cooperation Organisation and the Belt and Road Economic Initiative.
Use PyCharm for remote debugging of WSL on a Windo cf5c162d672e4e58b4dde5d797...shadow0702a
This document serves as a comprehensive step-by-step guide on how to effectively use PyCharm for remote debugging of the Windows Subsystem for Linux (WSL) on a local Windows machine. It meticulously outlines several critical steps in the process, starting with the crucial task of enabling permissions, followed by the installation and configuration of WSL.
The guide then proceeds to explain how to set up the SSH service within the WSL environment, an integral part of the process. Alongside this, it also provides detailed instructions on how to modify the inbound rules of the Windows firewall to facilitate the process, ensuring that there are no connectivity issues that could potentially hinder the debugging process.
The document further emphasizes on the importance of checking the connection between the Windows and WSL environments, providing instructions on how to ensure that the connection is optimal and ready for remote debugging.
It also offers an in-depth guide on how to configure the WSL interpreter and files within the PyCharm environment. This is essential for ensuring that the debugging process is set up correctly and that the program can be run effectively within the WSL terminal.
Additionally, the document provides guidance on how to set up breakpoints for debugging, a fundamental aspect of the debugging process which allows the developer to stop the execution of their code at certain points and inspect their program at those stages.
Finally, the document concludes by providing a link to a reference blog. This blog offers additional information and guidance on configuring the remote Python interpreter in PyCharm, providing the reader with a well-rounded understanding of the process.
3. Functions of the Data Link
Layer
• Provide service interface to the network
layer
• Dealing with transmission errors
• Regulating data flow
• Slow receivers not swamped by fast senders
4. Functions of the Data Link Layer
(2)
Relationship between packets and
frames.
5. Data Link Layer Design
Issues
• Services Provided to the Network
Layer
• Framing
• Error Control
• Flow Control
6. Services Provided to Network
Layer
(a) Virtual communication.
(b) Actual communication.
7. Services Provided to Network
Layer
The data link layer can be designed to offer various
services which are
Unacknowledged connectionless service
◦ the source machine send independent frames to the
destination machine without acknowledgement and no
connection.
Acknowledged connectionless service
◦ acknowledgement but no connection.
Acknowledged connection-oriented service.
◦ Connection first and then data transfer.
8. Services Provided to Network
Layer
When a frame arrives at a router, the hardware checks it
for errors, then passes to the data link layer software,
which checks to see if this is the frame expected, gives the
packet contained in the payload field to the routing
software, which then chooses the appropriate outgoing line
and passes the packet back down to the data link layer
software, which then transmits it.
9. Framing
The data link layer break the bit stream up into discrete
frames and compute the checksum for each frame.
When a frame arrives at the destination, the checksum is
recomputed.
Breaking the bit stream up into frames is based on the
following methods.
◦ Character count.
◦ Flag bytes with byte stuffing.
◦ Starting and ending flags, with bit stuffing.
◦ Physical layer coding violations.
10. Framing - Character Stream
This framing method uses a field in the header to specify the number of
characters in the frame.
When the data link layer at the destination sees the character count, it
knows how many characters follow and hence the end of the frame is
easily known.
The trouble with this algorithm is that the count can be garbled by a
transmission error.
11. Framing - Byte Stuffing
This method gets around the problem of resynchronization after an error
by having each frame start and end with FLAG bytes.
If the flag byte's bit pattern occurs in the data, an escape byte (ESC) is
inserted before flag byte.
A single escape byte is part of an escape sequence, whereas a doubled
one indicates that a single escape occurred naturally in the data.
12. Framing – Bit Stuffing
A disadvantage of Byte Stuffing is that it is closely tied to 8-bit
characters.
◦ Ex: UNICODE uses 16-bit characters
In Bit Stuffing, each frame begins and ends with a special bit pattern
◦ (ex: 01111110).
Whenever the sender's data link layer encounters five consecutive 1s in
the data, it automatically stuffs a 0 bit into the outgoing bit stream.
When the receiver sees five consecutive incoming 1 bits, followed by a 0
bit, it automatically destuffs the 0 bit.
13. Error Detection and
Correction
Error-Correcting Codes
◦ Redundant information is included along with
each block of data sent, to enable the receiver
to deduce what the transmitted data must have
been.
Error-Detecting Codes
◦ Enough redundancy is only included to allow
the receiver to deduce that an error occurred,
but not which error, and have it request a
14. Error-Correcting Codes
Error-Correcting Codes may be used for channels such as
wireless links that make many errors.
A frame consists of m data bits, r redundant (check ) bits and
an n-bit (m+r) codeword is obtained.
The number of bit positions in which two codewords differ is
called the Hamming distance.
If two codewords are a Hamming distance d apart, it will require
d single-bit errors to convert one into the other.
To detect d errors, you need a distance d + 1 code.
To correct d errors, you need a distance 2d + 1 code
15. Error-Correcting Codes
The bits that are powers of 2 (1, 2, 4, 8, 16, etc.) are check
bits.
The rest (3, 5, 6, 7, 9, etc.) are filled up with the m data bits.
Each check bit forces the parity of some collection of bits,
including itself, to be even .
To see which check bits the data bit in position k contributes
to, rewrite k as a sum of powers of 2.
For example, 11 = 1 + 2 + 8.
A bit is checked by just those check bits occurring in its
expansion (e.g., bit 11 is checked by bits 1, 2, and 8).
20. Burst Error Correction using
Hamming code
Hamming codes can only correct single errors.
However, to correct burst errors, a sequence of k consecutive
codewords are arranged as a matrix, one codeword per row.
The data should be transmitted one column at a time, starting with the
leftmost column.
When all k bits have been sent, the second column is sent.
When the frame arrives at the receiver, the matrix is reconstructed,
one column at a time.
If a burst error of length k occurs, at most 1 bit in each of the k
codewords will have been affected, but the Hamming code can correct
one error per codeword, so the entire block can be restored.
22. Error Detecting Codes
Through copper wire or fiber, the error rate is
much lower, so error detection and
retransmission is usually more efficient.
25. Cyclic Redundancy Check (CRC)
The most powerful technique used for error detection is CRC.
Unlike parity check which is based on addition, CRC is based on
binary division.
In CRC, a sequence of redundancy bits called the CRC
remainder is appended to the end of data bits.
This resulting codeword becomes exactly divisible by a second,
predetermined binary number.
At the destination, this received codeword is divided by the same
number.
◦ If there is no remainder, no error has occurred.
◦ If there is a remainder, error has occurred and codeword is
discarded.
27. Cyclic Redundancy Check
CRC is also known as polynomial code .
Polynomial codes are based upon treating bit strings as
representations of polynomials with coefficients of 0 and 1
only.
A k-bit frame is regarded as the coefficient list for a
polynomial with k terms, ranging from xk-1to x0.
Such a polynomial is said to be of degree k - 1.
The high-order (leftmost) bit is the coefficient of xk-1, the
next bit is the coefficient of xk-2 and so on.
Polynomial addition and subtraction are identical to ex-or
operation.
28. Checksum in CRC
When the polynomial code method is employed, the sender
and receiver must agree upon a generator polynomial, G(x), in
advance.
To compute the checksum for some frame with m bits,
corresponding to the polynomial M(x), the frame must be
longer than the generator polynomial.
The idea is to append a checksum to the end of the frame in
such a way that the polynomial represented by the
checksummed frame is divisible by G(x).
When the receiver gets the checksummed frame, it tries
29. Algorithm for computing the
checksum
Let r be the degree of G(x). Append r zero bits to the low-
order end of the frame so it now contains m + r bits and
corresponds to the polynomial xrM(x).
Divide the bit string corresponding to G(x) into the bit
string corresponding to xrM(x), using modulo 2 division.
Subtract the remainder (which is always r or fewer bits)
from the bit string corresponding to xrM(x) using modulo 2
subtraction.
The result is the checksummed frame to be transmitted.
Call its polynomial T(x).
33. Elementary Data Link
Protocols
• An Unrestricted Simplex Protocol
• A Simplex Stop-and-Wait Protocol
• A Simplex Protocol for a Noisy Channel
34. Unrestricted Simplex Protocol
This Protocol 1 is also known as Utopia.
The statement of the protocol
◦ Protocol 1 (Utopia) provides for data
transmission in one direction only, from sender
to receiver.
◦ The communication channel is assumed to be
error free and the receiver is assumed to be
able to process all the input infinitely quickly.
◦ Consequently, the sender just site in a loop
35. Simplex Stop-and-Wait
Protocol
This Protocol 2 is also known as Stop and Wait.
The statement of the protocol
◦ Protocol 2 (stop-and-wait) also provides for a one-
directional flow of data from sender to receiver.
◦ The communication channel is once again assumed to
be error free, as in protocol 1.
◦ However, this time, the receiver has only a finite buffer
capacity and a Unite processing speed, so the protocol
must explicitly prevent the sender from Hooding the
receiver with data faster than it can be handled.
36. A Simplex Protocol for a Noisy
Channel
• The network layer on A gives packet 1 to its data link layer.
The packet is correctly received at B and passed to the
network layer on B. B sends an acknowledgement frame
back to A.
• The acknowledgement frame gets lost completely. It just
never arrives at all because of the noisy channel .
• The data link layer on A eventually times out. Not having
received an acknowledgement, it assumes that its data
frame was lost or damaged and sends the frame containing
packet 1 again.
• The duplicate frame also arrives at the data link layer on B
perfectly and is unwittingly passed to the network layer there.
If A is sending a file to B, part of the file will be duplicated In
37. A Simplex Protocol for a Noisy
Channel
So, the receiver must be able to distinguish a frame that it is
seeing for the first time from a retransmission.
To achieve this is to have the sender put a sequence number in
the header of each frame it sends.
A 1-bit sequence number (0 or 1) is sufficient for the receiver to
detect the frame.
Any arriving frame containing the wrong sequence number is
rejected as a duplicate.
When a frame containing the correct sequence number arrives, it
is accepted and passed to the network layer.
Then the next expected sequence number is incremented modulo
2 (i.e., 0 becomes 1 and 1 becomes 0).
43. Sliding Window Protocols
In the previous protocols, data frames were transmitted in one
direction only.
In most practical situations, there is a need for transmitting
data in both directions.
The method of two separate communication channels for
achieving full-duplex data transmission is not preferred
because the bandwidth of the reverse channel is almost
entirely wasted.
The technique of temporarily delaying outgoing
acknowledgements so that they can be hooked onto the next
outgoing data frame is known as piggybacking .
45. Piggybacking advantages &
disadvantages
The advantage of using piggybacking over having distinct
acknowledgement frames is a better use of the available
channel bandwidth.
The ack field in the frame header costs only a few bits,
whereas a separate frame would need a header, the
acknowledgement, and a checksum.
Piggybacking introduces a complication not present with
separate acknowledgements.
If the data link layer waits longer than the sender's
timeout period, the frame will be retransmitted, defeating
the whole purpose of having acknowledgements.
46. Sliding Window Protocols
Sliding window protocols has three types of bidirectional
protocols which differ in terms of efficiency, complexity, and
buffer requirements.
In all sliding window protocols, each outbound frame contains a
sequence number, ranging from 0 upto maximum 2n-1
The sender maintains a set of sequence numbers corresponding
to frames it is permitted to send, which fall within a sending
window.
Similarly, the receiver also maintains a receiving window
corresponding to the set of frames it is permitted to accept.
The sender's window and the receiver's window need not have
the same lower and upper limits or even have the same size.
47. Sliding Window Protocols
The sequence numbers within the sender's window
represent frames that have been sent or can be sent but
are as yet not acknowledged.
Whenever a new packet arrives from the network layer, it
is given the next highest sequence number, and the
upper edge of the window is advanced by one.
When an acknowledgement comes in, the lower edge is
advanced by one.
In this way the window continuously maintains a list of
unacknowledged frames.
48. Sliding Window Protocols
Since frames currently within the sender's window may ultimately be lost or
damaged in transit, the sender must keep all these frames in its memory
for possible retransmission.
Thus, if the maximum window size is n, the sender needs n buffers to hold
the unacknowledged frames.
If the window ever grows to its maximum size, the sending data link layer
must forcibly shut off the network layer until another buffer becomes free.
The receiving data link layer's window corresponds to the frames it may
accept.
Any frame falling outside the window is discarded without comment.
When a frame whose sequence number is equal to the lower edge of the
window is received, it is passed to the network layer, an acknowledgement
is generated, and the window is rotated by one.
49. Sliding Window Protocols
• A One-Bit Sliding Window
Protocol
• A Protocol Using Go Back N
• A Protocol Using Selective
Repeat
50. A sliding window of size 1, with a 3-bit sequence number.
(a) Initial state.
(b) After the first frame has been sent.
(c) After the first frame has been received.
(d) After the first acknowledgement has been received.
One-Bit Sliding Window
Protocol
51. A One-Bit Sliding Window Protocol
(2)
Normal case. Abnormal case.
The notation is (seq, ack, packet number).
* denotes network layer accepts a packet.
52. A Protocol Using Go Back N
The need for a large window on the sending side occurs
whenever the product of bandwidth x round-trip-delay is large.
So, a large sliding window (size 2n -1) is preferred in this
protocol.
Go Back N - the receiver simply to discard all subsequent
frames, sending no acknowledgements for the discarded frames,
if any error occurs. This is also known as pipelining protocol.
58. Sliding Window Protocol
Using Selective repeat
In this protocol, both sender and receiver maintain a window of
acceptable sequence numbers.
The sender's window size starts out at 0 and grows to some
predefined maximum, MAX_SEQ.
The receiver's window, in contrast, is always fixed in size and equal to
M AX_SEQ.
The receiver has a buffer reserved for each sequence number within
its fixed window and associated with each buffer is a bit (arrived) telling
whether the buffer is full or empty.
Whenever a frame arrives, its sequence number is checked by the
function between to see if it falls within the window.
if so and if it has not already been received, it is accepted and stored.
59. Sliding Window Protocol
Using Selective repeat
Selective Repeat accepts frames out of order but passes
packets to the network layer in order.
Associated with each outstanding frame is a timer.
When the timer expires, only the error frame is
retransmitted, but not all the outstanding frames.
60. A Sliding Window Protocol Using Selective
Repeat (5)
(a) Initial situation with a window size seven.
(b) After seven frames sent and received, but not
acknowledged.
(c) Initial situation with a window size of four.
(d) After four frames sent and received, but not
acknowledged.
61. Example Data Link Protocols
• HDLC – High-Level Data Link
Control
• The Data Link Layer in the Internet
63. The Address field is primarily of importance on lines with
multiple terminals, where it is used to identify one of the
terminals.
The Control field is used for sequence numbers,
acknowledgements, and other purposes
The Data field may contain any information
The Checksum field is a cyclic redundancy code
The minimum frame contains three fields and totals 32
bits
HDLC Frame format
64. High-Level Data Link Control
Control field of
(a) An information frame.
(b) A supervisory frame.
(c) An unnumbered frame.
65. There are three kinds of frames: Information,
Supervisory, and Unnumbered
The protocol uses a sliding window, with a 3-bit
sequence number ( 7 unacknowledged frames)
The Seq field is the frame sequence number.
The Next field is a piggybacked acknowledgement
Poll/Final is used when a computer is polling a group
of terminals. When used as P, the computer is inviting the
terminal to send data. All the frames sent by the terminal,
except the final one, have the P/F bit set to P. The final
one is set to F.
HDLC Frame Types
66. A supervisory frame.
Type 0 is an acknowledgement frame (RECEIVE READY) used
to indicate the next frame expected
Type 1 is a negative acknowledgement frame (REJECT). It is
used to indicate that a transmission error has been detected
Type 2 is RECEIVE NOT READY. It acknowledges all frames up
to but not including Next, just as RECEIVE READY does, but it
tells the sender to stop sending
Type 3 is the SELECTIVE REJECT. It calls for retransmission of
only the frame specified
An Unnumbered frame
It is sometimes used for control purposes but can also carry data
when unreliable connectionless service is called for.
69. The Data Link Layer in the Internet
A home personal computer acting as an internet
host.
PPP – Point to Point Protocol
70. PPP Features
A framing method that unambiguously delineates the end of one
frame and the start of the next one. The frame format also
handles error detection.
A link control protocol for bringing lines up, testing them,
negotiating options, and bringing them down again gracefully
when they are no longer needed. This protocol is called LCP
(Link Control Protocol). It supports synchronous and
asynchronous circuits and byte-oriented and bit-oriented
encodings.
A way to negotiate network-layer options in a way that is
independent of the network layer protocol to be used. The
method chosen is to have a different NCP (Network Control
Protocol) for each network layer supported.
71. PPP – Point to Point Protocol
The PPP full frame format for
unnumbered mode operation.
72. PPP – Point to Point Protocol (2)
A simplified phase diagram for bring a line up and down.
73. PPP – Point to Point Protocol (3)
The LCP frame types.