Module 1: Introduction Lectures 8 hrs.
Fundamentals of wireless communication technology – the electromagnetic spectrum – radio
propagation mechanisms – characteristics of the wireless channel – Mobile Ad-hoc Networks
(MANETS) and Wireless Sensor Networks (WSNs): concepts and architectures. Applications
of Ad-hoc and sensor networks. Design challenges in Ad-hoc and sensor networks.
Issues in designing a routing and Transport Layer protocol for Ad hoc networks- proactive
routing, reactive routing (on-demand), hybrid routing- Classification of Transport Layer
solutions-TCP over Ad hoc wireless Networks
This document provides an overview of wireless sensor networks. It discusses wireless communication technologies, the need for wireless communication, and defines wireless sensor networks. It describes the characteristics, architecture, operating systems, applications, and technical challenges of wireless sensor networks. Finally, it discusses some companies that manufacture wireless sensor network products, including Cisco, IBM, and Libelium.
The document discusses several MAC protocols for ad hoc networks including MACA, MACAW, and PAMAS. MACA uses RTS and CTS packets to avoid collisions but does not provide ACK. MACAW is a revision of MACA that includes ACK. It significantly increases throughput but does not fully solve hidden and exposed terminal problems. PAMAS uses a separate signaling channel for RTS-CTS and a data channel. It allows nodes to power down transceivers when not transmitting to save energy.
How to put these nodes together to form a meaningful network.
How a network should function at high-level application scenarios .
On the basis of these scenarios and optimization goals, the design of networking protocols in wireless sensor networks are derived
A proper service interface is required and integration of WSNs into larger network contexts.
This document discusses various topics related to ad-hoc wireless networks including wireless network concepts, radio propagation mechanisms, characteristics of wireless channels, cellular networks, ad hoc networks, medium access control, routing protocols, multicasting, and transport layer protocols for ad hoc networks. It provides classifications and examples of different types of network architectures, protocols, and issues/challenges in ad hoc wireless networks.
This document summarizes several reactive routing protocols for mobile ad hoc networks (MANETs). Reactive protocols create routes only when needed by a source. Dynamic Source Routing uses route requests and replies to find paths, while Temporally-Ordered Routing Algorithm builds and maintains a directed acyclic graph rooted at destinations. Some protocols aim to improve quality of service or support real-time data streams through techniques like bandwidth estimation and mobility prediction. Source Routing with Local Recovery reduces overhead by allowing intermediate nodes to perform local error recovery using route caches when possible.
Issues in designing a routing and Transport Layer protocol for Ad hoc networks- proactive
routing, reactive routing (on-demand), hybrid routing- Classification of Transport Layer
solutions-TCP over Ad hoc wireless Networks
This document provides an overview of wireless sensor networks. It discusses wireless communication technologies, the need for wireless communication, and defines wireless sensor networks. It describes the characteristics, architecture, operating systems, applications, and technical challenges of wireless sensor networks. Finally, it discusses some companies that manufacture wireless sensor network products, including Cisco, IBM, and Libelium.
The document discusses several MAC protocols for ad hoc networks including MACA, MACAW, and PAMAS. MACA uses RTS and CTS packets to avoid collisions but does not provide ACK. MACAW is a revision of MACA that includes ACK. It significantly increases throughput but does not fully solve hidden and exposed terminal problems. PAMAS uses a separate signaling channel for RTS-CTS and a data channel. It allows nodes to power down transceivers when not transmitting to save energy.
How to put these nodes together to form a meaningful network.
How a network should function at high-level application scenarios .
On the basis of these scenarios and optimization goals, the design of networking protocols in wireless sensor networks are derived
A proper service interface is required and integration of WSNs into larger network contexts.
This document discusses various topics related to ad-hoc wireless networks including wireless network concepts, radio propagation mechanisms, characteristics of wireless channels, cellular networks, ad hoc networks, medium access control, routing protocols, multicasting, and transport layer protocols for ad hoc networks. It provides classifications and examples of different types of network architectures, protocols, and issues/challenges in ad hoc wireless networks.
This document summarizes several reactive routing protocols for mobile ad hoc networks (MANETs). Reactive protocols create routes only when needed by a source. Dynamic Source Routing uses route requests and replies to find paths, while Temporally-Ordered Routing Algorithm builds and maintains a directed acyclic graph rooted at destinations. Some protocols aim to improve quality of service or support real-time data streams through techniques like bandwidth estimation and mobility prediction. Source Routing with Local Recovery reduces overhead by allowing intermediate nodes to perform local error recovery using route caches when possible.
Localization with mobile anchor points in wireless sensor networksHabibur Rahman
The document describes a range-free localization scheme that uses mobile anchor points equipped with GPS to periodically broadcast their positions. Sensor nodes calculate their own positions based on the localization information from at least three mobile anchors without needing additional interactions. Simulation results showed the approach achieved fine-grained accuracy and was distributed, scalable, effective and power efficient. It performed better than other range-free localization mechanisms.
Unit 4 ec8702 - ad hoc and wireless sensor networks unit -4 mr.darwin nesaku...Darwin Nesakumar
This document provides an overview of sensor network security. It begins with objectives to learn about ad hoc and sensor network security aspects, attacks, and transport layer security issues. It then covers topics like security requirements, challenges in provisioning security, network security attacks categorized by layer (physical, data link, network, transport, application), and possible solutions for jamming, tampering, black hole attacks, and flooding attacks. The document also discusses key distribution, management techniques and procedures, and secure routing protocols like SPINS.
Mac protocols for ad hoc wireless networks Divya Tiwari
The document discusses MAC protocols for ad hoc wireless networks. It addresses key issues in designing MAC protocols including limited bandwidth, quality of service support, synchronization, hidden and exposed terminal problems, error-prone shared channels, distributed coordination without centralized control, and node mobility. Common MAC protocol classifications and examples are also presented, such as contention-based protocols, sender-initiated versus receiver-initiated protocols, and protocols using techniques like reservation, scheduling, and directional antennas.
Routing protocols for ad hoc wireless networks Divya Tiwari
The document discusses routing protocols for ad hoc wireless networks. It outlines several key challenges for these protocols, including mobility, bandwidth constraints, error-prone shared wireless channels, and hidden/exposed terminal problems. It also categorizes routing protocols based on how routing information is updated (proactively, reactively, or through a hybrid approach), whether they use past or future temporal network information, the type of network topology supported (flat or hierarchical), and how they account for specific resources like power.
This document discusses routing and multicast protocols at the MAC, routing, and application layers. It describes key modules like transmission, receiving, and neighbor list handling at the MAC layer. At the routing layer, it discusses unicast and multicast routing tables, forwarding, tree construction, and session maintenance. The application layer handles data transmission, multicast session initiation and termination, and route repair. It also compares source tree and shared tree approaches, and soft state and hard state maintenance mechanisms.
The document presents a graduate project on efficient data aggregation from polling points in wireless sensor networks. The proposed system called Mobi-Cluster aims to minimize overall network overhead and energy expenditure associated with multi-hop data retrieval while ensuring balanced energy consumption and prolonged network lifetime. This is achieved through building cluster structures consisting of member nodes that route data to assigned cluster heads, and selecting appropriate polling points to act as intermediaries between clusters and a mobile collector. The key stages of the Mobi-Cluster protocol are described as cluster head selection, polling point selection, cluster head attachment to polling points, data aggregation and forwarding to polling points, and communication between polling points and the mobile collector.
This document provides an overview of broadband and DSL technology. It discusses how broadband provides high-speed internet access from 256 kbps to several mbps. It then describes ADSL technology, how it works by splitting bandwidth on copper telephone lines into channels for upstream, downstream, and voice. The document outlines the various components used in broadband networks like DSLAMs, BRAS, CPE, and discusses how they connect and function. It also lists some services that can be accessed through broadband like video and audio on demand. In closing, it mentions how broadband can help bridge the digital divide and strengthen education through improved internet access.
1) El documento describe las tecnologías y procesos involucrados en el servicio de roaming, incluyendo la arquitectura de red, los flujos de llamadas, datos y SMS, y los procesos de registro, conciliación y facturación.
2) Explica las pruebas necesarias para lanzar un acuerdo de roaming, como las pruebas IREG para verificar los escenarios de llamadas y registro, y las pruebas TADIG para validar la facturación.
3) Detalla los mecanismos para prevenir el fraude en ro
CR : smart radio that has the ability to sense the external environment, learn from the history and make intelligent decisions to adjust its transmission parameters according
to the current state of the environment.
The document discusses fault tolerance techniques in wireless sensor networks (WSNs). It first reviews WSNs and types of failures that can occur, such as energy depletion, hardware failure, and communication link errors. It then covers approaches to fault detection including centralized (Sympathy, Secure Locations) and distributed (node self-detection, clustering). Fault recovery techniques like relay node placement, hop-by-hop TCP, and data aggregation are also summarized. The document aims to provide an overview of key aspects of fault tolerance in WSNs.
The document describes the key components and architecture of the GSM system. It discusses the objectives of GSM including supporting international roaming and good speech quality. It then describes the hierarchy of the GSM system including the mobile station, radio subsystem with base stations and base station controllers, and the network and switching subsystem with mobile switching centers and databases. It also discusses the air interface including frequency allocation and channel structure.
The PSTN is a network that connects customer equipment together through lines, trunks, and switches to allow communication. It has four major elements: customer premises equipment, the access system, transport, and signaling. The access system provides the wiring that connects customer equipment to the central network, including lines and trunks. It terminates at central office equipment. The transport component transmits signals through the core of the network using various transmission speeds and media between switches. A cellular call placed to a landline passes through the radio access network, mobile switching office, and the PSTN using its lines, trunks, and switches to connect the calls.
The document discusses next generation wireless networks (xG networks) and cognitive radios. It describes how xG networks will provide high bandwidth via heterogeneous architectures and dynamic spectrum access techniques enabled by cognitive radios. Cognitive radios allow opportunistic use of spectrum by performing spectrum sensing to detect available channels, spectrum management to select the best channel, spectrum sharing to coordinate channel access, and spectrum mobility to vacate channels for licensed users. The document outlines the key functions, architectures, and challenges of cognitive radio and xG networks.
This document provides an overview of the Global System for Mobile Communications (GSM). It discusses that GSM was created in 1982 to set a standard for mobile communications and the first system was deployed in 1991. The GSM architecture includes the mobile station, base station subsystem consisting of base transceiver stations and base station controllers, and the network and switching subsystem including mobile switching centers, home location register, and authentication center. GSM operates in the 900MHz and 1800MHz bands in India and uses frequency division duplex to provide communications between mobile devices and the network.
Mobile networks have evolved over several generations from 1G analog cellular to 4G LTE networks. This document provides an overview of the fundamental concepts and evolution of mobile networks including discussions of 2G, 3G, 4G networks and the Evolved Packet Core. It describes the core network functions and interfaces as well as basic network scenarios.
Public Switched Telephone Network (PSTN)J.T.A.JONES
The document discusses various aspects of the Public Switched Telephone Network (PSTN). It covers topics like modulation/demodulation schemes used to convert between analog and digital signals, the bandwidth of telephone lines, traditional modem standards like V.32, V.90, ADSL, techniques used for multiplexing like TDM and WDM, and components within switching offices. It provides technical details on how analog voice signals are converted to digital, transmitted through digital trunks, and switched within the network.
This document provides an introduction to the IEEE 802.11 wireless LAN standard. It outlines the standard's architecture including components like stations, basic service sets, extended service sets, and access points. It describes the medium access control sublayer which uses distributed coordination function and point coordination function to provide reliable data delivery and fair medium sharing. It also briefly discusses the physical layer and typical wireless LAN products.
This document discusses wireless sensor networks and their role in the Internet of Things. It defines sensor networks and their architecture, including sensor nodes that communicate wirelessly to a base station. It outlines challenges for sensor networks like fault tolerance, scalability, and quality of service. It also describes how sensor networks can be integrated into the Internet of Things through different approaches, with the first using a single gateway and later approaches using hybrid networks and access points. Applications of sensor networks in IoT include wearable devices collecting biometric data and communicating it to servers.
A complete power point presentation to know how Public Switching Telephone Network works. Useful for those in the working field or for the ones who want to know more or submitting any project report..
Radio waves are a form of electromagnetic radiation that are produced when an electric current oscillates in an antenna. They can carry data by modulating the wave, such as by changing its amplitude, frequency, or phase. Common modulation techniques include AM, FM, PSK, and FSK. Multiplexing allows multiple signals to be transmitted simultaneously over the same medium by allocating unique resources like frequency bands or time slots. Multiple access protocols like FDMA, TDMA, and CDMA are used to avoid interference from other users transmitting in the same spectrum.
Telecommunications refers to technologies used to convey information over distances. It includes systems like the telephone network, mobile phones, satellite communications, computer networks, the internet, and radio/television broadcasting. While communication has existed since ancient times using methods like drums and smoke signals, modern telecommunications began with inventions in the 19th century like the telegraph and telephone. Today's telecommunications industry continues developing new technologies and services, applying fundamental principles from early telephony and radio.
Localization with mobile anchor points in wireless sensor networksHabibur Rahman
The document describes a range-free localization scheme that uses mobile anchor points equipped with GPS to periodically broadcast their positions. Sensor nodes calculate their own positions based on the localization information from at least three mobile anchors without needing additional interactions. Simulation results showed the approach achieved fine-grained accuracy and was distributed, scalable, effective and power efficient. It performed better than other range-free localization mechanisms.
Unit 4 ec8702 - ad hoc and wireless sensor networks unit -4 mr.darwin nesaku...Darwin Nesakumar
This document provides an overview of sensor network security. It begins with objectives to learn about ad hoc and sensor network security aspects, attacks, and transport layer security issues. It then covers topics like security requirements, challenges in provisioning security, network security attacks categorized by layer (physical, data link, network, transport, application), and possible solutions for jamming, tampering, black hole attacks, and flooding attacks. The document also discusses key distribution, management techniques and procedures, and secure routing protocols like SPINS.
Mac protocols for ad hoc wireless networks Divya Tiwari
The document discusses MAC protocols for ad hoc wireless networks. It addresses key issues in designing MAC protocols including limited bandwidth, quality of service support, synchronization, hidden and exposed terminal problems, error-prone shared channels, distributed coordination without centralized control, and node mobility. Common MAC protocol classifications and examples are also presented, such as contention-based protocols, sender-initiated versus receiver-initiated protocols, and protocols using techniques like reservation, scheduling, and directional antennas.
Routing protocols for ad hoc wireless networks Divya Tiwari
The document discusses routing protocols for ad hoc wireless networks. It outlines several key challenges for these protocols, including mobility, bandwidth constraints, error-prone shared wireless channels, and hidden/exposed terminal problems. It also categorizes routing protocols based on how routing information is updated (proactively, reactively, or through a hybrid approach), whether they use past or future temporal network information, the type of network topology supported (flat or hierarchical), and how they account for specific resources like power.
This document discusses routing and multicast protocols at the MAC, routing, and application layers. It describes key modules like transmission, receiving, and neighbor list handling at the MAC layer. At the routing layer, it discusses unicast and multicast routing tables, forwarding, tree construction, and session maintenance. The application layer handles data transmission, multicast session initiation and termination, and route repair. It also compares source tree and shared tree approaches, and soft state and hard state maintenance mechanisms.
The document presents a graduate project on efficient data aggregation from polling points in wireless sensor networks. The proposed system called Mobi-Cluster aims to minimize overall network overhead and energy expenditure associated with multi-hop data retrieval while ensuring balanced energy consumption and prolonged network lifetime. This is achieved through building cluster structures consisting of member nodes that route data to assigned cluster heads, and selecting appropriate polling points to act as intermediaries between clusters and a mobile collector. The key stages of the Mobi-Cluster protocol are described as cluster head selection, polling point selection, cluster head attachment to polling points, data aggregation and forwarding to polling points, and communication between polling points and the mobile collector.
This document provides an overview of broadband and DSL technology. It discusses how broadband provides high-speed internet access from 256 kbps to several mbps. It then describes ADSL technology, how it works by splitting bandwidth on copper telephone lines into channels for upstream, downstream, and voice. The document outlines the various components used in broadband networks like DSLAMs, BRAS, CPE, and discusses how they connect and function. It also lists some services that can be accessed through broadband like video and audio on demand. In closing, it mentions how broadband can help bridge the digital divide and strengthen education through improved internet access.
1) El documento describe las tecnologías y procesos involucrados en el servicio de roaming, incluyendo la arquitectura de red, los flujos de llamadas, datos y SMS, y los procesos de registro, conciliación y facturación.
2) Explica las pruebas necesarias para lanzar un acuerdo de roaming, como las pruebas IREG para verificar los escenarios de llamadas y registro, y las pruebas TADIG para validar la facturación.
3) Detalla los mecanismos para prevenir el fraude en ro
CR : smart radio that has the ability to sense the external environment, learn from the history and make intelligent decisions to adjust its transmission parameters according
to the current state of the environment.
The document discusses fault tolerance techniques in wireless sensor networks (WSNs). It first reviews WSNs and types of failures that can occur, such as energy depletion, hardware failure, and communication link errors. It then covers approaches to fault detection including centralized (Sympathy, Secure Locations) and distributed (node self-detection, clustering). Fault recovery techniques like relay node placement, hop-by-hop TCP, and data aggregation are also summarized. The document aims to provide an overview of key aspects of fault tolerance in WSNs.
The document describes the key components and architecture of the GSM system. It discusses the objectives of GSM including supporting international roaming and good speech quality. It then describes the hierarchy of the GSM system including the mobile station, radio subsystem with base stations and base station controllers, and the network and switching subsystem with mobile switching centers and databases. It also discusses the air interface including frequency allocation and channel structure.
The PSTN is a network that connects customer equipment together through lines, trunks, and switches to allow communication. It has four major elements: customer premises equipment, the access system, transport, and signaling. The access system provides the wiring that connects customer equipment to the central network, including lines and trunks. It terminates at central office equipment. The transport component transmits signals through the core of the network using various transmission speeds and media between switches. A cellular call placed to a landline passes through the radio access network, mobile switching office, and the PSTN using its lines, trunks, and switches to connect the calls.
The document discusses next generation wireless networks (xG networks) and cognitive radios. It describes how xG networks will provide high bandwidth via heterogeneous architectures and dynamic spectrum access techniques enabled by cognitive radios. Cognitive radios allow opportunistic use of spectrum by performing spectrum sensing to detect available channels, spectrum management to select the best channel, spectrum sharing to coordinate channel access, and spectrum mobility to vacate channels for licensed users. The document outlines the key functions, architectures, and challenges of cognitive radio and xG networks.
This document provides an overview of the Global System for Mobile Communications (GSM). It discusses that GSM was created in 1982 to set a standard for mobile communications and the first system was deployed in 1991. The GSM architecture includes the mobile station, base station subsystem consisting of base transceiver stations and base station controllers, and the network and switching subsystem including mobile switching centers, home location register, and authentication center. GSM operates in the 900MHz and 1800MHz bands in India and uses frequency division duplex to provide communications between mobile devices and the network.
Mobile networks have evolved over several generations from 1G analog cellular to 4G LTE networks. This document provides an overview of the fundamental concepts and evolution of mobile networks including discussions of 2G, 3G, 4G networks and the Evolved Packet Core. It describes the core network functions and interfaces as well as basic network scenarios.
Public Switched Telephone Network (PSTN)J.T.A.JONES
The document discusses various aspects of the Public Switched Telephone Network (PSTN). It covers topics like modulation/demodulation schemes used to convert between analog and digital signals, the bandwidth of telephone lines, traditional modem standards like V.32, V.90, ADSL, techniques used for multiplexing like TDM and WDM, and components within switching offices. It provides technical details on how analog voice signals are converted to digital, transmitted through digital trunks, and switched within the network.
This document provides an introduction to the IEEE 802.11 wireless LAN standard. It outlines the standard's architecture including components like stations, basic service sets, extended service sets, and access points. It describes the medium access control sublayer which uses distributed coordination function and point coordination function to provide reliable data delivery and fair medium sharing. It also briefly discusses the physical layer and typical wireless LAN products.
This document discusses wireless sensor networks and their role in the Internet of Things. It defines sensor networks and their architecture, including sensor nodes that communicate wirelessly to a base station. It outlines challenges for sensor networks like fault tolerance, scalability, and quality of service. It also describes how sensor networks can be integrated into the Internet of Things through different approaches, with the first using a single gateway and later approaches using hybrid networks and access points. Applications of sensor networks in IoT include wearable devices collecting biometric data and communicating it to servers.
A complete power point presentation to know how Public Switching Telephone Network works. Useful for those in the working field or for the ones who want to know more or submitting any project report..
Radio waves are a form of electromagnetic radiation that are produced when an electric current oscillates in an antenna. They can carry data by modulating the wave, such as by changing its amplitude, frequency, or phase. Common modulation techniques include AM, FM, PSK, and FSK. Multiplexing allows multiple signals to be transmitted simultaneously over the same medium by allocating unique resources like frequency bands or time slots. Multiple access protocols like FDMA, TDMA, and CDMA are used to avoid interference from other users transmitting in the same spectrum.
Telecommunications refers to technologies used to convey information over distances. It includes systems like the telephone network, mobile phones, satellite communications, computer networks, the internet, and radio/television broadcasting. While communication has existed since ancient times using methods like drums and smoke signals, modern telecommunications began with inventions in the 19th century like the telegraph and telephone. Today's telecommunications industry continues developing new technologies and services, applying fundamental principles from early telephony and radio.
INTRODUCTION TO RADIO COMMUNICATION SYSTEMS 1.docxCyprianObota
Communication requires a sender, a message, a transmission medium, a receiver, and understanding. Radio communication works by encoding a message as an electromagnetic wave that travels through the air and is received and decoded. Repeaters extend the range of handheld radios by receiving a signal and retransmitting it, allowing communication over obstacles. Range depends on both power and frequency - higher power mobile radios have greater range than lower power handhelds, while higher frequencies penetrate buildings better than lower VHF bands.
Lecture on mobile radio environme, nt.pptNanaAgyeman13
The document discusses reasons why wireless signals are difficult to send and receive. It explains that radio channels are random due to multipath propagation from reflections, diffractions, and scattering caused by buildings, foliage and terrain. This creates interference between signals, shadowing effects, and small-scale fading. Additional challenges include interference between users and service providers. Accurately characterizing wireless channels requires statistical analysis and field measurements due to their unpredictable nature.
1. The document introduces radio communication and its history, including early experiments by Maxwell, Hertz, Tesla, and Marconi in the late 19th century.
2. It describes the classification of radio waves by frequency range and the basic mechanisms, components, and uses of radio transmitters, receivers, and technology like amplitude modulation and frequency modulation.
3. Advantages of radio communication are its low cost and ability to transmit without wires, while disadvantages are low data rates and inability to transmit video or images. Future technologies discussed include cognitive radio networks.
This document discusses radio wave propagation for medium range communication. It covers the following key points:
1. Radio frequencies between 1-30 MHz are used for medium range communication. This allows efficient radiation from practical transmitter antennas between 1/4 and 1 wavelength in size.
2. There are three main propagation mechanisms: line of sight, ground wave, and sky wave. Line of sight and ground waves are used above 50 MHz for terrestrial communication. Sky waves reflect off the ionosphere and are used from 1-30 MHz for long distance communication.
3. The radio frequency spectrum is divided into bands like HF, VHF, UHF etc. with different applications. Wavelength decreases with increasing frequency based on the
Mobile satellite communication uses satellites to enable communication between mobile users. There are different types of satellite orbits used - geostationary, medium earth orbit, and low earth orbit. Each orbit has advantages and disadvantages for mobile communication. Mobile satellite services include maritime, land, aeronautical, personal, and broadcast. Signal propagation is impaired by effects like reflection, refraction, shadowing, and different types of noise. Thermal noise places a fundamental limit on communication performance.
The document discusses key aspects of wireless communication reference models including:
1. It describes the layers of the reference model from the physical layer up to the application layer and their main functions.
2. It covers topics like frequency ranges used for wireless transmission, common modulation techniques, and effects of signal propagation like multipath propagation.
3. It discusses technologies and standards used for wireless networks and regulations set by organizations like ITU.
The document summarizes various physical layer transmission media and wireless transmission methods. It describes guided transmission media like twisted pair, coaxial cable, and fiber optics. It then discusses wireless transmission, including the electromagnetic spectrum, radio transmission using radio waves, microwave transmission, infrared and millimeter waves, and light waves. The document concludes by covering communication satellites in geostationary orbit, medium earth orbit, and low earth orbit.
Radio waves and propagation and astronomyNayem Uddin
Radio waves are a type of electromagnetic radiation that have wavelengths in the electromagnetic spectrum. They can travel at the speed of light and have different frequencies and propagation properties depending on their wavelength. Radio waves were first predicted by Maxwell and demonstrated by Hertz in the late 1800s. They are now used for various technologies like radio, television, wireless networks, GPS, and more. International organizations like ITU regulate radio wave usage through frequency allocation and regional guidelines.
Transmission media is the physical medium used to transmit data between a sender and receiver. The two main types are guided and unguided media. Guided media uses physical pathways like cables to direct signals over shorter distances at high speeds securely. Common examples are twisted pair, coaxial, and fiber optic cables. Unguided media transmits electromagnetic waves without physical pathways, broadcasting signals through the air over longer distances less securely. Common examples are radio waves, microwaves, and infrared waves used in wireless technologies.
Physical Layer - Mobile and Wireless Devices – Simplified Reference Model – Need for Mobile Computing – Wireless Transmissions – Multiplexing – Spread Spectrum and Cellular Systems
This document discusses various propagation models used in wireless communications. It begins by introducing the free space propagation model and 2-ray ground reflection model. It then describes the key propagation mechanisms of reflection, diffraction, and scattering. Reflection from smooth surfaces and conductors is explained. Fresnel zone geometry and knife edge diffraction models are used to analyze diffraction. Buildings can help diffraction by providing some gain, with the amount of diffracted energy dependent on factors like height and frequency. Propagation effects must be considered for accurate wireless system design and performance prediction.
Microwave transmission refers to using radio waves between 1-30 GHz to transmit information or power. Microwaves are well-suited for point-to-point wireless communication because their short wavelengths allow for directional antennas that do not interfere with nearby equipment using the same frequencies. Microwaves also provide a very large information-carrying capacity. Common uses of microwaves include wireless communication systems, radar, satellite communications, and radio astronomy. Sources of microwaves include vacuum tube devices, solid-state devices, and natural sources like the sun and cosmic microwave background radiation.
Radio waves are electromagnetic waves that transmit data wirelessly over long distances. They transmit signals by fluctuating evenly through space on certain frequencies. The radio uses a transmitter to encode signals into radio waves and a receiver to decode the waves back into the original signal. Different technologies like radio, television, cell phones, and WiFi use radio waves to transmit signals without wires.
Radio waves are electromagnetic waves that can transmit data over long distances. They transmit signals by fluctuating evenly through space on certain frequencies. The radio uses a transmitter to encode signals into radio waves using sine waves, and a receiver to decode the sine waves back into the original signal. Different technologies like radio, television, cell phones, and WiFi use radio waves to transmit signals through the air or space.
Radio waves transmit data, music, and other signals by sending invisible waves over long distances using different frequencies. They transmit through sine waves which are detected by receivers. Radio waves are used for technologies like radio, cell phones, Bluetooth, wireless internet, and more. They can travel via surface waves along the Earth, sky waves reflected by the ionosphere, or space waves like for satellite communication. Common frequency bands include AM/FM radio, television, and shortwave.
Chap 02 antenna & wave propagation EngkaderAMuse
This document summarizes key concepts about antennas and wireless signal propagation. It discusses different types of antennas like dipole antennas and parabolic reflective antennas. It also describes the main modes of wireless signal propagation including ground-wave propagation, sky-wave propagation, and line-of-sight propagation. Additionally, it outlines several factors that can impair wireless signals during propagation, such as attenuation, noise, multipath, and atmospheric absorption.
This project report was submitted by 4 students from Sitamarhi Institute of Technology for their Bachelor of Technology degree in Computer Science and Engineering. It documents their project work on an unspecified topic for partial fulfillment of their degree requirements. The report includes declarations by the students and their guide, acknowledgments, and outlines the introduction, related work, objectives, requirements, proposed work, system design, code, results, conclusion, and references. It was certified by the guide and head of the department.
Cyber security concepts and terminology are introduced, including the CIA triad of confidentiality, integrity, and availability. Various cyber attacks, threats, and exploits are defined, such as denial of service attacks, social engineering, and zero-day exploits. Information gathering techniques like footprinting, scanning, and enumeration are explained. Free and open source tools for scanning networks, including Nmap and Zenmap, are also covered.
The document discusses various types of malware like viruses, worms, trojans, spyware, ransomware, and backdoors. It explains what malware is, how it infects systems, and its objectives. Various malware analysis techniques like static analysis, dynamic analysis, code analysis, and behavioral analysis are also summarized. The document also discusses antivirus software, how it works, and examples like Bitdefender, Avast, and Panda. It covers memory management techniques and task management.
The document discusses several topics related to cyber security including biometrics, mobile device hardening, web application security, identity management for web services, authorization patterns, security considerations, and challenges. Specifically, it provides best practices for securing evolving technologies, mobile devices, web servers, web services, implementing identity management, common authorization patterns, important security considerations, and challenges related to implementing security.
The document discusses cybersecurity laws, regulations, and forensics. It provides an overview of cyber laws, which govern internet usage and cybercrimes. Cyber forensics is the process of collecting and analyzing digital evidence for cybercrime investigations. The document also discusses India's National Cyber Security Policy 2013, which aims to create a secure cyber environment in India through public-private partnerships and developing cybersecurity skills. Cybersecurity standards and the roles of governments and the private sector in ensuring cybersecurity are also summarized.
This document provides an overview of cyber security topics including cryptography, cryptanalysis, symmetric and asymmetric key cryptography, hashing, digital signatures, firewalls, user management, and virtual private networks (VPNs). It defines these terms and concepts, compares different techniques like symmetric vs asymmetric cryptography, and packet filtering vs stateful inspection firewalls. The document also discusses the importance of using firewalls and how VPNs can provide privacy and anonymity online.
This document provides an overview of various topics related to cyber security including infrastructure and network security, system security, server security, operating system (OS) security, physical security, network packet sniffing, network design simulation, denial of service (DOS) and distributed denial of service (DDOS) attacks, asset management and audits, intrusion detection and prevention techniques, host-based intrusion prevention systems, security information management, network session analysis, system integrity validation, and some open-source, free and trial tools that can be used for security purposes like DOS/DDOS attacks, packet sniffing, firewalls, and intrusion detection.
The document discusses several topics related to cyber security including vulnerabilities, safeguards, internet security, cloud computing security, and social network security. Some common cyber security vulnerabilities mentioned are weak passwords, outdated software, phishing attacks, malware, and data breaches. Safeguards to address these vulnerabilities include strong passwords, regular software updates, employee training, encryption, access controls and monitoring. The document also outlines security challenges and mitigation strategies for internet usage, cloud computing and social media platforms.
Photosynthesis converts light energy to chemical energy in chloroplasts using chlorophyll. Chloroplasts contain thylakoids which are stacked to form grana. Photosynthesis uses carbon dioxide, water, and light energy to produce glucose and oxygen. The light reactions in thylakoid membranes use photosystems to split water, producing ATP, NADPH, and oxygen. The Calvin cycle in the chloroplast stroma uses ATP and NADPH to reduce carbon dioxide into glucose.
This document discusses different types of gene interactions and single gene disorders. It describes how gene expression can be affected by other genes, either through allelic or non-allelic interaction. Epistasis occurs when a gene's effect depends on the presence or absence of other genes. Single gene disorders can result from mutations in dominant, recessive, or X-linked genes. X-linked disorders particularly affect males since they only have one X chromosome.
Genetics is the scientific study of heredity and inherited variations. Offspring acquire genes from parents through the inheritance of chromosomes. Sexual reproduction combines genes from two parents, leading to genetically diverse offspring. Meiosis produces haploid gametes with one set of chromosomes through two cell divisions in the ovaries and testes. During fertilization, the egg and sperm unite forming a zygote that develops into a multicellular organism through mitosis.
1. The document discusses the key differences between science and engineering. Science aims to understand natural laws through observation, while engineering applies scientific knowledge to solve problems and develop new technologies.
2. It also discusses the importance of studying biology for engineers. Biology can help engineers understand living systems and inspire new designs. It can also help solve problems involving biological processes.
3. The document then answers several questions about basic biology concepts. It defines biology and lists the key characteristics of living organisms. It also explains concepts like Mendel's laws of inheritance, gene interaction, the genetic code, and compares mechanisms of bird flight and aircraft flight.
Enzymes are globular proteins that act as biological catalysts, speeding up chemical reactions without being consumed. They are typically named after their substrate with the suffix "-ase". Enzyme activity can be monitored by measuring changes in substrate or product concentration. Mass spectrometry provides an alternative detection method without needing a chromophore. The enzyme binds its substrate at the active site, forming an enzyme-substrate complex. This lowers the activation energy and allows the reaction to proceed, with the unaltered enzyme then dissociating to catalyze more reactions. Kinetic analysis reveals the individual reaction steps and how enzyme activity is controlled.
Gregor Mendel conducted experiments breeding pea plants to discover the basic principles of heredity. He found that organisms have discrete factors (now known as genes) that determine traits, which exist in two versions (alleles). During reproduction, parents contribute one of each allele to offspring randomly. Mendel also discovered that traits are inherited independently and that dominant alleles mask recessive alleles when both are present. His work formed the basis of classical genetics and established the laws of segregation and independent assortment.
Microbiology is the study of single-celled organisms called microorganisms. Microorganisms are classified into three domains: Archaea, Bacteria, and Eukarya. They are identified using staining techniques, molecular and phylogenetic analysis, growth in special media, microscopy, and other methods. Microscopes, including light microscopes and electron microscopes, are important tools used to visualize microorganisms. Light microscopes use visible light while electron microscopes use electron beams. Microorganisms demonstrate flexibility in surviving extreme environments and use various energy and carbon sources. Studying them provides insights into relationships between life and the environment.
The document discusses biology concepts including the differences between science and engineering, the need for engineers to study biology, the definition and characteristics of living organisms, the working principles of the human eye and digital cameras, Mendel's laws of inheritance, genetic code, gene interaction, and epistasis. It provides detailed explanations of these concepts through examples and definitions in response to multiple questions. The key points are that science aims to understand nature while engineering applies scientific knowledge, biology is relevant for engineering fields involving living systems, and genetics concepts such as Mendel's laws, genetic code, and gene interaction help explain inheritance and variation in traits.
This document discusses the classification of life and the hierarchy of life forms. It notes that biologists categorize organisms into groups and subgroups to make their study easier. Classification is based on characteristics like morphology, anatomy, biochemistry, and ecology. All living things share common themes of organization, information processing, energy and matter transformation, and interactions at different hierarchical levels. Cells are the basic unit of life, and while they can differ, they all descend from earlier cells and share common features. Organisms are classified as unicellular or multicellular depending on whether they are composed of single or multiple cells.
Amino acids are organic molecules that contain an amine group, a carboxyl group, a central carbon atom called the alpha carbon, and a variable side chain. There are 20 common amino acids that differ in their side chains and physical/chemical properties. Amino acids can polymerize through peptide bonds between their carboxyl and amine groups to form polypeptides. Polypeptides are linear chains of amino acids that can further fold into three-dimensional protein structures and carry out biological functions.
Biology is the scientific study of life and living organisms. It explores the structure, function, development, behavior, and evolution of living things through various subdisciplines. The fundamental units of biology are the cell, genes, and evolution. Biology seeks to understand the mechanisms that allow living things to maintain their internal organization and adapt to environmental changes.
Scaling Connections in PostgreSQL Postgres Bangalore(PGBLR) Meetup-2 - MydbopsMydbops
This presentation, delivered at the Postgres Bangalore (PGBLR) Meetup-2 on June 29th, 2024, dives deep into connection pooling for PostgreSQL databases. Aakash M, a PostgreSQL Tech Lead at Mydbops, explores the challenges of managing numerous connections and explains how connection pooling optimizes performance and resource utilization.
Key Takeaways:
* Understand why connection pooling is essential for high-traffic applications
* Explore various connection poolers available for PostgreSQL, including pgbouncer
* Learn the configuration options and functionalities of pgbouncer
* Discover best practices for monitoring and troubleshooting connection pooling setups
* Gain insights into real-world use cases and considerations for production environments
This presentation is ideal for:
* Database administrators (DBAs)
* Developers working with PostgreSQL
* DevOps engineers
* Anyone interested in optimizing PostgreSQL performance
Contact info@mydbops.com for PostgreSQL Managed, Consulting and Remote DBA Services
Implementations of Fused Deposition Modeling in real worldEmerging Tech
The presentation showcases the diverse real-world applications of Fused Deposition Modeling (FDM) across multiple industries:
1. **Manufacturing**: FDM is utilized in manufacturing for rapid prototyping, creating custom tools and fixtures, and producing functional end-use parts. Companies leverage its cost-effectiveness and flexibility to streamline production processes.
2. **Medical**: In the medical field, FDM is used to create patient-specific anatomical models, surgical guides, and prosthetics. Its ability to produce precise and biocompatible parts supports advancements in personalized healthcare solutions.
3. **Education**: FDM plays a crucial role in education by enabling students to learn about design and engineering through hands-on 3D printing projects. It promotes innovation and practical skill development in STEM disciplines.
4. **Science**: Researchers use FDM to prototype equipment for scientific experiments, build custom laboratory tools, and create models for visualization and testing purposes. It facilitates rapid iteration and customization in scientific endeavors.
5. **Automotive**: Automotive manufacturers employ FDM for prototyping vehicle components, tooling for assembly lines, and customized parts. It speeds up the design validation process and enhances efficiency in automotive engineering.
6. **Consumer Electronics**: FDM is utilized in consumer electronics for designing and prototyping product enclosures, casings, and internal components. It enables rapid iteration and customization to meet evolving consumer demands.
7. **Robotics**: Robotics engineers leverage FDM to prototype robot parts, create lightweight and durable components, and customize robot designs for specific applications. It supports innovation and optimization in robotic systems.
8. **Aerospace**: In aerospace, FDM is used to manufacture lightweight parts, complex geometries, and prototypes of aircraft components. It contributes to cost reduction, faster production cycles, and weight savings in aerospace engineering.
9. **Architecture**: Architects utilize FDM for creating detailed architectural models, prototypes of building components, and intricate designs. It aids in visualizing concepts, testing structural integrity, and communicating design ideas effectively.
Each industry example demonstrates how FDM enhances innovation, accelerates product development, and addresses specific challenges through advanced manufacturing capabilities.
For the full video of this presentation, please visit: https://www.edge-ai-vision.com/2024/07/intels-approach-to-operationalizing-ai-in-the-manufacturing-sector-a-presentation-from-intel/
Tara Thimmanaik, AI Systems and Solutions Architect at Intel, presents the “Intel’s Approach to Operationalizing AI in the Manufacturing Sector,” tutorial at the May 2024 Embedded Vision Summit.
AI at the edge is powering a revolution in industrial IoT, from real-time processing and analytics that drive greater efficiency and learning to predictive maintenance. Intel is focused on developing tools and assets to help domain experts operationalize AI-based solutions in their fields of expertise.
In this talk, Thimmanaik explains how Intel’s software platforms simplify labor-intensive data upload, labeling, training, model optimization and retraining tasks. She shows how domain experts can quickly build vision models for a wide range of processes—detecting defective parts on a production line, reducing downtime on the factory floor, automating inventory management and other digitization and automation projects. And she introduces Intel-provided edge computing assets that empower faster localized insights and decisions, improving labor productivity through easy-to-use AI tools that democratize AI.
How Netflix Builds High Performance Applications at Global ScaleScyllaDB
We all want to build applications that are blazingly fast. We also want to scale them to users all over the world. Can the two happen together? Can users in the slowest of environments also get a fast experience? Learn how we do this at Netflix: how we understand every user's needs and preferences and build high performance applications that work for every user, every time.
Sustainability requires ingenuity and stewardship. Did you know Pigging Solutions pigging systems help you achieve your sustainable manufacturing goals AND provide rapid return on investment.
How? Our systems recover over 99% of product in transfer piping. Recovering trapped product from transfer lines that would otherwise become flush-waste, means you can increase batch yields and eliminate flush waste. From raw materials to finished product, if you can pump it, we can pig it.
Data Protection in a Connected World: Sovereignty and Cyber Securityanupriti
Delve into the critical intersection of data sovereignty and cyber security in this presentation. Explore unconventional cyber threat vectors and strategies to safeguard data integrity and sovereignty in an increasingly interconnected world. Gain insights into emerging threats and proactive defense measures essential for modern digital ecosystems.
Are you interested in learning about creating an attractive website? Here it is! Take part in the challenge that will broaden your knowledge about creating cool websites! Don't miss this opportunity, only in "Redesign Challenge"!
UiPath Community Day Kraków: Devs4Devs ConferenceUiPathCommunity
We are honored to launch and host this event for our UiPath Polish Community, with the help of our partners - Proservartner!
We certainly hope we have managed to spike your interest in the subjects to be presented and the incredible networking opportunities at hand, too!
Check out our proposed agenda below 👇👇
08:30 ☕ Welcome coffee (30')
09:00 Opening note/ Intro to UiPath Community (10')
Cristina Vidu, Global Manager, Marketing Community @UiPath
Dawid Kot, Digital Transformation Lead @Proservartner
09:10 Cloud migration - Proservartner & DOVISTA case study (30')
Marcin Drozdowski, Automation CoE Manager @DOVISTA
Pawel Kamiński, RPA developer @DOVISTA
Mikolaj Zielinski, UiPath MVP, Senior Solutions Engineer @Proservartner
09:40 From bottlenecks to breakthroughs: Citizen Development in action (25')
Pawel Poplawski, Director, Improvement and Automation @McCormick & Company
Michał Cieślak, Senior Manager, Automation Programs @McCormick & Company
10:05 Next-level bots: API integration in UiPath Studio (30')
Mikolaj Zielinski, UiPath MVP, Senior Solutions Engineer @Proservartner
10:35 ☕ Coffee Break (15')
10:50 Document Understanding with my RPA Companion (45')
Ewa Gruszka, Enterprise Sales Specialist, AI & ML @UiPath
11:35 Power up your Robots: GenAI and GPT in REFramework (45')
Krzysztof Karaszewski, Global RPA Product Manager
12:20 🍕 Lunch Break (1hr)
13:20 From Concept to Quality: UiPath Test Suite for AI-powered Knowledge Bots (30')
Kamil Miśko, UiPath MVP, Senior RPA Developer @Zurich Insurance
13:50 Communications Mining - focus on AI capabilities (30')
Thomasz Wierzbicki, Business Analyst @Office Samurai
14:20 Polish MVP panel: Insights on MVP award achievements and career profiling
GDG Cloud Southlake #34: Neatsun Ziv: Automating AppsecJames Anderson
The lecture titled "Automating AppSec" delves into the critical challenges associated with manual application security (AppSec) processes and outlines strategic approaches for incorporating automation to enhance efficiency, accuracy, and scalability. The lecture is structured to highlight the inherent difficulties in traditional AppSec practices, emphasizing the labor-intensive triage of issues, the complexity of identifying responsible owners for security flaws, and the challenges of implementing security checks within CI/CD pipelines. Furthermore, it provides actionable insights on automating these processes to not only mitigate these pains but also to enable a more proactive and scalable security posture within development cycles.
The Pains of Manual AppSec:
This section will explore the time-consuming and error-prone nature of manually triaging security issues, including the difficulty of prioritizing vulnerabilities based on their actual risk to the organization. It will also discuss the challenges in determining ownership for remediation tasks, a process often complicated by cross-functional teams and microservices architectures. Additionally, the inefficiencies of manual checks within CI/CD gates will be examined, highlighting how they can delay deployments and introduce security risks.
Automating CI/CD Gates:
Here, the focus shifts to the automation of security within the CI/CD pipelines. The lecture will cover methods to seamlessly integrate security tools that automatically scan for vulnerabilities as part of the build process, thereby ensuring that security is a core component of the development lifecycle. Strategies for configuring automated gates that can block or flag builds based on the severity of detected issues will be discussed, ensuring that only secure code progresses through the pipeline.
Triaging Issues with Automation:
This segment addresses how automation can be leveraged to intelligently triage and prioritize security issues. It will cover technologies and methodologies for automatically assessing the context and potential impact of vulnerabilities, facilitating quicker and more accurate decision-making. The use of automated alerting and reporting mechanisms to ensure the right stakeholders are informed in a timely manner will also be discussed.
Identifying Ownership Automatically:
Automating the process of identifying who owns the responsibility for fixing specific security issues is critical for efficient remediation. This part of the lecture will explore tools and practices for mapping vulnerabilities to code owners, leveraging version control and project management tools.
Three Tips to Scale the Shift Left Program:
Finally, the lecture will offer three practical tips for organizations looking to scale their Shift Left security programs. These will include recommendations on fostering a security culture within development teams, employing DevSecOps principles to integrate security throughout the development
How to Avoid Learning the Linux-Kernel Memory ModelScyllaDB
The Linux-kernel memory model (LKMM) is a powerful tool for developing highly concurrent Linux-kernel code, but it also has a steep learning curve. Wouldn't it be great to get most of LKMM's benefits without the learning curve?
This talk will describe how to do exactly that by using the standard Linux-kernel APIs (locking, reference counting, RCU) along with a simple rules of thumb, thus gaining most of LKMM's power with less learning. And the full LKMM is always there when you need it!
Navigating Post-Quantum Blockchain: Resilient Cryptography in Quantum Threatsanupriti
In the rapidly evolving landscape of blockchain technology, the advent of quantum computing poses unprecedented challenges to traditional cryptographic methods. As quantum computing capabilities advance, the vulnerabilities of current cryptographic standards become increasingly apparent.
This presentation, "Navigating Post-Quantum Blockchain: Resilient Cryptography in Quantum Threats," explores the intersection of blockchain technology and quantum computing. It delves into the urgent need for resilient cryptographic solutions that can withstand the computational power of quantum adversaries.
Key topics covered include:
An overview of quantum computing and its implications for blockchain security.
Current cryptographic standards and their vulnerabilities in the face of quantum threats.
Emerging post-quantum cryptographic algorithms and their applicability to blockchain systems.
Case studies and real-world implications of quantum-resistant blockchain implementations.
Strategies for integrating post-quantum cryptography into existing blockchain frameworks.
Join us as we navigate the complexities of securing blockchain networks in a quantum-enabled future. Gain insights into the latest advancements and best practices for safeguarding data integrity and privacy in the era of quantum threats.
Hire a private investigator to get cell phone recordsHackersList
Learn what private investigators can legally do to obtain cell phone records and track phones, plus ethical considerations and alternatives for addressing privacy concerns.
Coordinate Systems in FME 101 - Webinar SlidesSafe Software
If you’ve ever had to analyze a map or GPS data, chances are you’ve encountered and even worked with coordinate systems. As historical data continually updates through GPS, understanding coordinate systems is increasingly crucial. However, not everyone knows why they exist or how to effectively use them for data-driven insights.
During this webinar, you’ll learn exactly what coordinate systems are and how you can use FME to maintain and transform your data’s coordinate systems in an easy-to-digest way, accurately representing the geographical space that it exists within. During this webinar, you will have the chance to:
- Enhance Your Understanding: Gain a clear overview of what coordinate systems are and their value
- Learn Practical Applications: Why we need datams and projections, plus units between coordinate systems
- Maximize with FME: Understand how FME handles coordinate systems, including a brief summary of the 3 main reprojectors
- Custom Coordinate Systems: Learn how to work with FME and coordinate systems beyond what is natively supported
- Look Ahead: Gain insights into where FME is headed with coordinate systems in the future
Don’t miss the opportunity to improve the value you receive from your coordinate system data, ultimately allowing you to streamline your data analysis and maximize your time. See you there!
An invited talk given by Mark Billinghurst on Research Directions for Cross Reality Interfaces. This was given on July 2nd 2024 as part of the 2024 Summer School on Cross Reality in Hagenberg, Austria (July 1st - 7th)
Are you interested in dipping your toes in the cloud native observability waters, but as an engineer you are not sure where to get started with tracing problems through your microservices and application landscapes on Kubernetes? Then this is the session for you, where we take you on your first steps in an active open-source project that offers a buffet of languages, challenges, and opportunities for getting started with telemetry data.
The project is called openTelemetry, but before diving into the specifics, we’ll start with de-mystifying key concepts and terms such as observability, telemetry, instrumentation, cardinality, percentile to lay a foundation. After understanding the nuts and bolts of observability and distributed traces, we’ll explore the openTelemetry community; its Special Interest Groups (SIGs), repositories, and how to become not only an end-user, but possibly a contributor.We will wrap up with an overview of the components in this project, such as the Collector, the OpenTelemetry protocol (OTLP), its APIs, and its SDKs.
Attendees will leave with an understanding of key observability concepts, become grounded in distributed tracing terminology, be aware of the components of openTelemetry, and know how to take their first steps to an open-source contribution!
Key Takeaways: Open source, vendor neutral instrumentation is an exciting new reality as the industry standardizes on openTelemetry for observability. OpenTelemetry is on a mission to enable effective observability by making high-quality, portable telemetry ubiquitous. The world of observability and monitoring today has a steep learning curve and in order to achieve ubiquity, the project would benefit from growing our contributor community.
Paradigm Shifts in User Modeling: A Journey from Historical Foundations to Em...Erasmo Purificato
Slide of the tutorial entitled "Paradigm Shifts in User Modeling: A Journey from Historical Foundations to Emerging Trends" held at UMAP'24: 32nd ACM Conference on User Modeling, Adaptation and Personalization (July 1, 2024 | Cagliari, Italy)
INDIAN AIR FORCE FIGHTER PLANES LIST.pdfjackson110191
These fighter aircraft have uses outside of traditional combat situations. They are essential in defending India's territorial integrity, averting dangers, and delivering aid to those in need during natural calamities. Additionally, the IAF improves its interoperability and fortifies international military alliances by working together and conducting joint exercises with other air forces.
What Not to Document and Why_ (North Bay Python 2024)Margaret Fero
We’re hopefully all on board with writing documentation for our projects. However, especially with the rise of supply-chain attacks, there are some aspects of our projects that we really shouldn’t document, and should instead remediate as vulnerabilities. If we do document these aspects of a project, it may help someone compromise the project itself or our users. In this talk, you will learn why some aspects of documentation may help attackers more than users, how to recognize those aspects in your own projects, and what to do when you encounter such an issue.
These are slides as presented at North Bay Python 2024, with one minor modification to add the URL of a tweet screenshotted in the presentation.
What Not to Document and Why_ (North Bay Python 2024)
Adhoc module 1 Introduction
1. UNIT I:
Introduction : Fundamentals of Wireless Communication Technology, The
Electromagnetic Spectrum, Radio propagation Mechanisms ,Characteristics of the
Wireless channel , mobile ad hoc networks (MANETs) and Wireless Sensor Networks
(WSNs): concepts and architectures, Applications of Ad Hoc and Sensor Networks,
Design Challenges in Ad hoc and Sensor Networks.
Fundamentals of Wireless Communication Technology
Fundamentals of wireless communication technology:
Wireless Communication is a broad and dynamic field that has spurred tremendous
excitement and technological advance over the last few decades. Wireless Communication is,
by any measure, the fastest growing segment of the communications industry. As such as it
has captured the attention of the media and the imagination of the public. Cellular systems
have experienced exponential growth over the last decade and there are currently about two
billion users worldwide.
Evolution of Wireless Communication
There are several smaller steps that take place in leading up to the development of a new
technology . Tracing the development of these earlier discoveries in brief can help us better
understand how this technology actually functions and contributes towards what could be the
next development. A brief review of the history of wireless communications covering radio,
television, radar, satellite, wireless and mobile cellular and other wireless networks are
presented in the following paragraph.
Radio and Television Communications
In 1874, Marconi performed simple experiments to send signals using electromagnetic waves
at short distances of only about 100 meters. At that time scientists and experts believed that
electromagnetic waves could only be transmitted in a straight line, and the main obstacle to
radio transmission was the curvature of the earth’s surface. Finally Marconi successfully
experimented to prove that electromagnetic wave transmission was possible between two
distant points even through obstacles in between.
Radar Communication
Radar has been recognized as one of the greatest scientific developments of the first half of
the 20th century. The first practical radar system was produced in 1935 by the British
physicist Robert Watson-Watt. Radar is an active remote-sensing system that operates on the
principle of echoes. A Radar display shows a map like picture of the area being scanned. The
centre of the picture corresponds to the radar antenna and the radar echoes are shown as
bright spots on the screen. Satellite Communication A satellite is an object that orbits or
revolves around another object. Satellites can be sent into space through a variety of launch
vehicles. Sir Isaac Newton in the 1720s was probably the first person to conceive the idea of
a satellite. In 1945, Arthur C Clarke a science fiction envisioned a network of a
communication satellite. Three satellites would be able to transmit signals around the world
by transmitting in a line-of-sight direction with other orbiting satellites.
Cellular Communication
2. In 1946, American Telephone & Telegraph (AT&T) introduced the first American
commercial mobile radio telephone service to private customers. It consisted of a central
transmitter with one antenna which could serve a wide area.
The electromagnetic spectrum radio propagation:
Wireless communication is based on the principle of broadcast and reception of
electromagnetic waves. These waves can be characterized by their frequency (f) or their
wavelength (λ). Frequency is the number of cycles (oscillations) per second of the wave
and is measured in Hertz (Hz). The speed of propagation of these waves (c) varies from
medium to medium, except in a vacuum where all electromagnetic waves travel at the
same speed, the speed of light. The relation between the above parameters can be given as
c = λ × f where c is the speed of light (3 × 108m/s), f is the frequency of the wave in Hz,
and λ is its wavelength in meters. Table 1 Frequency bands and their common uses
3. The low-frequency bands comprised of the radio, microwave, infrared, and visible light
portions of the spectrum can be used for information transmission by modulating the
amplitude, frequency, or the phase of the waves. Radio waves are easy to generate and are
widely used for both indoor and outdoor communication due to properties such as their
ability to pass through buildings and ability to travel long distances.
1) Radio waves
• Easy to generate and are widely used for both indoor and outdoor communication
due to properties such as their ability to pass through buildings and ability to travel long
distances.
• Radio transmission is omni directional.
2) Propagation waves
• VLF, LF, and MF bands the propagation of waves, also called as ground waves,
follows the curvature of the Earth.
• The maximum transmission ranges of these waves are of the order of a few hundred
kilometers.
• The HF and VHF band transmissions are absorbed by the atmosphere near the
Earth's surface. However, a portion of the radiation, called the sky wave radiates
outward and upward to the ionosphere in the upper atmosphere.
3) Microwave
Microwave transmissions (in the SHF band) tend to travel in straight lines and hence
can be narrowly focused.
• Microwaves were widely used for long-distance telephony, before they got replaced
by fiber optics.
• They are also widely used for mobile phones and television transmission. Since the
energy is concentrated.
4) Infrared waves
• Infrared waves and waves in the EHF band (also known as millimeter waves) are
used for short range communication.
• They are widely used in television, VCR, and stereo remote controls.
5) Visible light
• The visible light part of the spectrum is just after the infrared portion.
• Unguided optical signaling using visible light provides very high bandwidth at a
very low cost.
• But the main disadvantage here is that it is very difficult to focus a very narrow
unidirectional laser beam, which limits the maximum distance between the transmitter
and receiver.
4. In the VLF, LF, and MF bands the propagation of waves, also called as ground
waves, follows the curvature of the Earth. The maximum transmission ranges of these
waves are of the order of a few hundred kilometers. They are used for low bandwidth
transmissions such as amplitude modulated.
Radio Propagation Mechanisms
Radio waves generally experience the following three propagation mechanisms:
• Reflection:
When the propagating radio wave hits an object which is very large compared to its
wavelength (such as the surface of the Earth, or tall buildings), the wave gets reflected by
that object. Reflection causes a phase shift of 180 degrees between the incident and the
reflected rays.
• Diffraction:
This propagation effect is undergone by a wave when it hits an impenetrable object. The
wave bends at the edges of the object, thereby propagating in different directions. This
phenomenon is termed as diffraction. The dimensions of the object causing diffraction are
comparable to the wavelength of the wave being diffracted. The bending causes the wave
to reach places behind the object which generally cannot be reached by the line-of-sight
transmission. The amount of diffraction is frequency-dependent, with the lower frequency
waves diffracting more.
• Scattering:
When the wave travels through a medium, which contains many objects with dimensions
small when compared to its wavelength, scattering occurs. The wave gets scattered into
several weaker outgoing signals. In practice, objects such as street signs, lamp posts, and
foliage cause scattering.
Characteristics of wireless channels:
1. Path Loss
• Path loss can be expressed as the ratio of the power of the transmitted signal to the
power of the same signal received by the receiver, on a given path. It is a function of
the propagation distance.
• Path loss is dependent on a number of factors such as the radio frequency used and
the nature of the terrain.
• So, several models are required to describe the variety of transmission
environments.
There are two path loss model, i. Free propagation model ii. Two ray model or two path
model
Free propagation model :
The simplest path loss model in which there is a direct-path signal between the transmitter
and the receiver, with no atmospheric attenuation or multipath components.
5. The relationship between the transmitted power Pt and the received power Pr is given by
Where Gt and Gr are the transmitter and receiver antenna gains, 1 respectively, in the
direction from the transmitter to the receiver, d is the distance between the transmitter and
receiver, and λ= c/f (is the wavelength of the signal).
Two ray model :
The signal reaches the receiver through two paths, one a line-of sight path, and the other the
path through which the reflected (or refracted, or scattered) wave is received. According to
the two-path model, the received power is given by
Where Pt is the transmitted power, Gt and Gr represent the antenna gains at the transmitter
and the receiver, respectively, d is the distance between the transmitter and receiver, and ht
and hr are the heights of the transmitter and the receiver, respectively.
2. Fading
Fading refers to the fluctuations in signal strength when received at the receiver.
Fading can be classified into two types:
i. Fast fading/small-scale fading
ii. Slow fading/large-scale fading.
i. Fast fading refers to the rapid fluctuations in the amplitude, phase, or multipath
delays of the received signal, due to the interference between multiple versions
(copies) of the same transmitted signal arriving at the receiver at slightly different
times.
The time between the reception of the first version of the signal and the last
echoed signal is called delay spread. The multipath propagation of the
transmitted signal, which causes fast fading.
The multipath propagation of the transmitted signal, which causes fast fading.
The multiple signal paths may sometimes add constructively or sometimes
destructively at the receiver, causing a variation in the power level of the
received signal.
ii. Slow fading occurs when objects that partially absorb the transmissions lie between
the transmitter and receiver.
Slow fading is so called because the duration of the fade may last for multiple seconds
or minutes.
Slow fading may occur when the receiver is inside a building and the radio wave must
pass through the walls of a building, or when the receiver is temporarily shielded from
the transmitter by a building.
6. Slow fading is also referred to as shadow fading since the objects that cause the fade,
which may be large buildings or other structures, block the direct transmission path
from the transmitter to the receiver.
Some common measures to overcome the fading effect are (a) Diversity (b)Adaptive
modulation
(a) Diversity Mechanism
Based on the fact that independent paths between the same transmitter and
receiver nodes experience independent fading effects. By providing multiple
logical channels between the transmitter and receiver, and sending parts of the
signal over each channel, the error effects due to fading can be compensated.
i. Time diversity mechanisms aim at spreading the data over time so that the
effects of burst errors are minimized.
ii. Frequency diversity mechanisms spread the transmission over a wider
frequency spectrum, or use multiple carriers for transmitting the information.
iii. Space diversity involves the use of different physical transmission paths.
(b) Adaptive Modulation Mechanisms
The channel characteristics are estimated at the receiver and the estimates are
sent by the receiver to the transmitter through a feedback channel.
The transmitter adapts its transmissions based on the received channel
estimates in order to counter the errors that could occur due to the
characteristics of the channel. Adaptive techniques are usually very complex
to implement.
3. Interference
Wireless transmissions have to counter interference from a wide variety of
sources. Two main forms of interference are adjacent channel interference and
co-channel interference.
i. Adjacent channel interference case, signals in nearby frequencies have
components outside their allocated ranges. These components may
interfere with on-going transmissions in the adjacent frequencies. It
can be avoided by carefully introducing guard bands2 between the
allocated frequency ranges.
ii. Co-channel interference, sometimes also referred to as narrow-band
interference, is due to other nearby systems the same transmission
frequency. Narrow-band interference due to frequency reuse in cellular
systems can be minimized with the use of multiuser detection.
Mobile ad hoc networks (MANETs)
MANET stands for Mobile adhoc Network also called as wireless adhoc network or adhoc
wireless network. They consist of set of mobile nodes connected wirelessly in a self
configured, self healing network without having a fixed infrastructure. MANET nodes are
free to move randomly as the network topology changes frequently.
Types of MANET –
1. Vehicular Ad hoc Network (VANETs) –
Enable effective communication with another vehicle or with the roadside
equipments.Intelligent vehicular ad hoc networks(InVANETs) deals with another vehicle or
with the roadside euipments.
2. Smart Phone Ad hoc Network (SPANC) –
To create peer-to-peer network without relying on cellular carrier networks, wireless access
7. points or traditional network infrasture.Here peer can join or leave the network without
destroying it.
3. Internet based Mobile Ad hoc Network (iMANETs) –
It supports internet protocols such as TCP/UDP and IP. To link mobile nodes and
establish routes distributed and automatically.
4. Hub-Spoke MANET:
Multiple sub MANET’s may be connected in hub-spoke VPN to create a
geographically destributed MANET. Normal Ad-hoc routing algorithm does not apply
directly.
5. Military or Tactical MANETs –
This is used by the military units. Emphasis on data rate, real time demand, fast re-
routing during mobility, security, radio range, etc.
6. Flying Ad hoc Network (FANETs) –
This is composed of unmanned aerial vehicle (commonly known as drone). Provides
links to remote areas and mobility.
Architecture of MANET:
The Architecture of Mobile Ad Hoc Network (MANET) is shown in the figure below and it
is grouped into three main classifications which are as follows:
Enabling Technologies: Considering the coverage area, these are further divided into
various classes like
BAN (Body Area Network): The communication range is 1-2 meters and the BAN provides
the connectivity to devices that may be attached to wearable computers
PAN (Personal Area Network): The communication range is up to 10 meters and the PAN
helps to connect the mobile devices to another mobile devices or stationary devices.
WLANs (Wireless Local Area Networks): The communication range is 100-500 meters for
single building or the group of buildings. WAN (Wide Area Network) and MAN
8. (Metropolitan Area Network) are mobile multi-hop wireless networks that still faces
various challenges like security, addressing, location management etc.
Networking: In MANET, the greater part of the principle functionalities of the Networking
protocols should be redesigned for the self configuring, dynamic, unstable, peer-to-peer
communication environment. The primary focus of networking protocols is to utilize the one-
hop transmission services which are given by the enabling technologies to develop end-to-
end reliable services, from a sender to one receiver(s). To establish an end-to-end
communication the sender needs to find the receiver inside the network. The fundamental
point of a location service is to dynamically map the address of the receiver device to its
present location in the network
Middleware and applications: The presentation of new innovations like WiFi, Bluetooth,
IEEE 802.11, WiMAX and HyperLAN enormously encourages the deployment of ad hoc
technology and new ad hoc networking applications mainly in specific fields like emergency
services, disaster recovery and environment monitoring. In addition, the adaptability of
MANET makes this innovation alluring for a few practical situations like, for instance, in
PAN, home networking, home networking, law enforcement operation, commercial and
educational applications, and sensor network. Mobile ad hoc frameworks as of currently
created adopt the methodology of not having a middleware, yet rather depend on every
application to handle every one of the services it needs.
Wireless Sensor Networks (WSNs): concepts and architectures
A Wireless Sensor Network is one kind of wireless network includes a large number of
circulating, self-directed, minute, low powered devices named sensor nodes called motes.
These networks certainly cover a huge number of spatially distributed, little, battery-operated,
embedded devices that are networked to caringly collect, process, and transfer data to the
operators, and it has controlled the capabilities of computing & processing. Nodes are the tiny
computers, which work jointly to form the networks.
9. The sensor node is a multi-functional, energy efficient wireless device. The applications
of motes in industrial are widespread. A collection of sensor nodes collects the data from
the surroundings to achieve specific application objectives. The communication between
motes can be done with each other using transceivers. In a wireless sensor network, the
number of motes can be in the order of hundreds/ even thousands. In contrast with sensor
n/ws, Ad Hoc networks will have fewer nodes without any structure.
Wireless Sensor Network Architecture
The most common WSN architecture follows the OSI architecture Model. The architecture of
the WSN includes five layers and three cross layers. Mostly in sensor n/w we require five
layers, namely application, transport, n/w, data link & physical layer. The three cross planes
are namely power management, mobility management, and task management. These layers of
the WSN are used to accomplish the n/w and make the sensors work together in order to raise
the complete efficiency of the network.
10. Application Layer
The application layer is liable for traffic management and offers software for numerous
applications that convert the data in a clear form to find positive information. Sensor
networks arranged in numerous applications in different fields such as agricultural, military,
environment, medical, etc.
Transport Layer
The function of the transport layer is to deliver congestion avoidance and reliability where a
lot of protocols intended to offer this function are either practical on the upstream. These
protocols use dissimilar mechanisms for loss recognition and loss recovery. The transport
layer is exactly needed when a system is planned to contact other networks.
Providing a reliable loss recovery is more energy efficient and that is one of the main reasons
why TCP is not fit for WSN. In general, Transport layers can be separated into Packet driven,
Event driven. There are some popular protocols in the transport layer namely STCP (Sensor
Transmission Control Protocol), PORT (Price-Oriented Reliable Transport Protocol and
PSFQ (pump slow fetch quick).
Network Layer
The main function of the network layer is routing, it has a lot of tasks based on the
application, but actually, the main tasks are in the power conserving, partial memory, buffers,
and sensor don’t have a universal ID and have to be self-organized.
The simple idea of the routing protocol is to explain a reliable lane and redundant lanes,
according to a convinced scale called metric, which varies from protocol to protocol. There
are a lot of existing protocols for this network layer, they can be separate into; flat routing
and hierarchal routing or can be separated into time driven, query-driven & event driven.
Data Link Layer
11. The data link layer is liable for multiplexing data frame detection, data streams, MAC, &
error control, confirm the reliability of point–point (or) point– multipoint.
Physical Layer
The physical layer provides an edge for transferring a stream of bits above physical medium.
This layer is responsible for the selection of frequency, generation of a carrier frequency,
signal detection, Modulation & data encryption. IEEE 802.15.4 is suggested as typical for
low rate particular areas & wireless sensor network with low cost, power consumption,
density, the range of communication to improve the battery life. CSMA/CA is used to support
star & peer to peer topology. There are several versions of IEEE 802.15.4.V.
Characteristics of Wireless Sensor Network
The characteristics of WSN include the following.
The consumption of Power limits for nodes with batteries
Capacity to handle with node failures
Some mobility of nodes and Heterogeneity of nodes
Scalability to large scale of distribution
Capability to ensure strict environmental conditions
Simple to use
Cross-layer design
Advantages of Wireless Sensor Networks
The advantages of WSN include the following
Network arrangements can be carried out without immovable infrastructure.
Apt for the non-reachable places like mountains, over the sea, rural areas and deep forests.
Flexible if there is a casual situation when an additional workstation is required.
Execution pricing is inexpensive.
It avoids plenty of wiring.
It might provide accommodations for the new devices at any time.
It can be opened by using a centralized monitoring.
Applications of Ad Hoc and Sensor Networks
1. Wireless Adhoc Network :
A wireless ad-hoc network is a wireless network deployed without any framework or
infrastructure. This incorporates wireless mesh networks, mobile ad-hoc networks, and
vehicular ad-hoc networks. It’s history could be traced back to the Defense Advanced
Research Project Agency (DARPA) and Packet Radio Networks (PRNET) which evolved
into the Survival Adaptive Radio Networks (SARNET) program. Wireless ad-hoc
networks, in particular mobile ad-hoc networks (MANET), are growing very fast as they
make communication simpler and progressively accessible. In any case, their conventions
or protocols will in general be hard to structure due to topology dependent behavior of
wireless communication, and their distributed and adaptive operations to topology
dynamism. They are allowed to move self-assertively at any time. So, the network topology
of MANET may change randomly and rapidly at unpredictable times. This makes routing
difficult because the topology is continually changing and nodes cannot be expected to have
steady data storage.
Applications:
12. 1. Data Mining
2. Military battlefield
3. Commercial Sector
4. Personal area network or Bluetooth
5. collaborative and distributed computing;
6. emergency and rescue operations;
7. mesh networks;
8. hybrid cellular/ad-hoc wireless networks.
2. Wireless Sensor Network :
A wireless sensor network can be characterized as a system of devices, indicated as nodes
which can detect the environment and impart the data accumulated from the monitored field
(e.g., a zone or volume) through remote or wireless connections. It can be depicted as a
system of nodes that agreeably sense and may control the environment enabling association
between people or computers and the surrounding environment. The information is sent,
possibly through different jumps, to a sink (indicated as a controller or monitor) that can
utilize it locally or is associated with different systems (e.g., The Internet) through a portal.
The nodes can be fixed or moving.
Applications:
1. Environmental Monitoring
2. Health Care
3. Positioning and Monitoring
4. Military Applications
5. Home Applications
6. Commercial Applications
7. Area monitoring
8. Air pollution monitoring
9. Forest fire detection
10. Landslide detection
11. Water quality monitoring
12. Industrial monitoring
Design Challenges in Ad hoc and Sensor Networks.
Design Challenges of sensor network
Sensor networks pose certain design challenges due to the following reasons:
Sensor nodes are randomly deployed and hence do not fit into any regular
topology. Once deployed, they usually do not require any human intervention.
Hence, the setup and maintenance of the network should be entirely
autonomous.
Sensor networks are infrastructure-less. Therefore, all routing and
maintenance algorithms need to be distributed.
An important bottleneck in the operation of sensor nodes is the available
energy. Sensors usually rely only on their battery for power, which in many
cases cannot be recharged or replaced. Hence, the available energy at the
nodes should be considered as a major constraint while designing protocols.
For instance, it is desirable to give the user an option to trade off network
lifetime for fault tolerance or accuracy of results.
Hardware design for sensor nodes should also consider energy efficiency as a
primary requirement. The micro-controller, operating system, and application
software should be designed to conserve power.
13. Sensor nodes should be able to synchronize with each other in a completely
distributed manner, so that TDMA schedules can be imposed and temporal
ordering of detected events can be performed without ambiguity.
A sensor network should also be capable of adapting to changing connectivity
due to the failure of nodes, or new nodes powering up. The routing protocols
should be able to dynamically include or avoid sensor nodes in their paths.
Real-time communication over sensor networks must be supported through
provision of guarantees on maximum delay, minimum bandwidth, or other
QoS parameters.
Provisions must be made for secure communication over sensor networks,
especially for military applications which carry sensitive data.
Design challeneges in Adhoc Networks
There are many challenges in design, deployment, and performance of ad hoc:
• Medium access scheme;
• Routing and multicasting;
• Transport layer protocol;
• Pricing scheme;
• Quality of service provisioning;
• Security;
• Energy management;
• Addressing and service discovery;
• Scalability;
• Deployment considerations.
Routing
The responsibility of any routing protocol
• determining a feasible path to a destination based on a certain criterion;
• discovering, storing, and exchanging routing information;
• gathering information about a path breaks and updating route information accordingly.
Challenges for routing protocol in ad-hoc networks:
• Mobility;
• Bandwidth constraints;
• Resource constraints;
• Erroneous transmission medium;
• Location-dependent contention: