Introduction wireless communication networkRiazul Islam
The document provides an overview of wireless communications and networks. It discusses the history of wireless technologies and how digital communications provide noise immunity over analog signals. It also describes the basic components of a communication system including the transmitter, channel, and receiver. Additionally, it defines key terms related to wireless systems such as mobile station, base station, and handoff. The document outlines some examples of wireless communication systems and highlights challenges in wireless communications compared to wired systems.
Introduction to basics of wireless networks such as
• Radio waves & wireless signal encoding techniques
• Wireless networking issues & constraints
• Wireless internetworking devices
Radio waves are electromagnetic waves that are used for various communication technologies beyond just audio broadcasting. They transmit data for Bluetooth, mobile phones, television, Wi-Fi, and radar by using different frequency ranges. Television uses radio waves between 54-1600 MHz to transmit combined visual and audio entertainment on multiple channels. Mobile phones use radio waves between 824-849 MHz to transmit calls and messages between devices. Bluetooth allows short-distance communication between devices from 2400-2483 MHz. Radar detects objects' presence and speed by transmitting radio waves of varying frequencies. Wi-Fi enables wireless networking between devices using varying radio wave frequencies to connect to the internet via routers.
TELVASS Systems is an Indian company that designs and manufactures high-quality, customized wireless products and components at competitive prices. It has expertise in antenna design and development through its in-house R&D department. The company aims to be a global leader in supplying cost-effective wireless solutions and maintaining high quality standards and customer service.
This document provides an overview of frequency reuse and planning in radio architecture for cellular and PCS networks. It discusses the history of wireless communication and the allocation of spectrum for cellular and PCS bands. It also describes PCS licensing, including licensed narrowband, licensed broadband, and unlicensed spectrum. Key challenges for PCS licensees in establishing successful networks are also summarized.
The document defines communication and its basic elements, which are a transmitter, channel, and receiver. It describes transmission media as the pathway that carries information between sender and receiver. The two main types are wired/guided media and wireless/unguided media. It also discusses analog and digital signals, periodic vs aperiodic signals, baseband vs broadband transmission, noise and signal-to-noise ratio, multiplexing, and provides short notes on communication through the ionosphere and DSB-SC and VSB modulation techniques.
The bandwidth of a signal is defined as the difference between the upper and lower frequencies of the signal. It represents the range of frequencies occupied by the signal and is measured in Hertz (Hz). Different types of signals have different bandwidths. For example, the bandwidth of a voice signal is 300-3400 Hz, while the bandwidth of a music signal is 20-15000 Hz. Bandwidth is calculated differently for analog and digital signals, with analog bandwidth based on frequency and digital bandwidth on bit rate.
Fm transmitter and future radio technologyChima Chukwu
ABSTRACT
FM Transmitter is a device which generates frequency modulated signal. It is
one element of a radio system which, with the aid of an antenna, propagates
an electromagnetic signal. Standard FM broadcasts are based in the 88 - 108
MHz range. Advancements have been made in the way FM is broadcast. This
includes utilizing such technologies as Hybrid Digital (HD) Radio, Software
Defined Radio (SDR) and Cognitive Radio.
HD Radio uses IBOC (In-Band On-Channel) as a methodof broadcasting digital
radio signals on the same FM channel, and at the same time as the
conventional analog signal while Software defined radio (SDR) is the term used
to describe radio technology where some or the entire wireless physical layer
functions are software defined.
Cognitive radio networks on the other hand, are intelligent networks that can
automatically sense the environment and adapt the communication
parameters accordingly. These types of networks have applications in dynamic
spectrum access, co-existence of different wireless networks, interference
management, etc.
Introduction wireless communication networkRiazul Islam
The document provides an overview of wireless communications and networks. It discusses the history of wireless technologies and how digital communications provide noise immunity over analog signals. It also describes the basic components of a communication system including the transmitter, channel, and receiver. Additionally, it defines key terms related to wireless systems such as mobile station, base station, and handoff. The document outlines some examples of wireless communication systems and highlights challenges in wireless communications compared to wired systems.
Introduction to basics of wireless networks such as
• Radio waves & wireless signal encoding techniques
• Wireless networking issues & constraints
• Wireless internetworking devices
Radio waves are electromagnetic waves that are used for various communication technologies beyond just audio broadcasting. They transmit data for Bluetooth, mobile phones, television, Wi-Fi, and radar by using different frequency ranges. Television uses radio waves between 54-1600 MHz to transmit combined visual and audio entertainment on multiple channels. Mobile phones use radio waves between 824-849 MHz to transmit calls and messages between devices. Bluetooth allows short-distance communication between devices from 2400-2483 MHz. Radar detects objects' presence and speed by transmitting radio waves of varying frequencies. Wi-Fi enables wireless networking between devices using varying radio wave frequencies to connect to the internet via routers.
TELVASS Systems is an Indian company that designs and manufactures high-quality, customized wireless products and components at competitive prices. It has expertise in antenna design and development through its in-house R&D department. The company aims to be a global leader in supplying cost-effective wireless solutions and maintaining high quality standards and customer service.
This document provides an overview of frequency reuse and planning in radio architecture for cellular and PCS networks. It discusses the history of wireless communication and the allocation of spectrum for cellular and PCS bands. It also describes PCS licensing, including licensed narrowband, licensed broadband, and unlicensed spectrum. Key challenges for PCS licensees in establishing successful networks are also summarized.
The document defines communication and its basic elements, which are a transmitter, channel, and receiver. It describes transmission media as the pathway that carries information between sender and receiver. The two main types are wired/guided media and wireless/unguided media. It also discusses analog and digital signals, periodic vs aperiodic signals, baseband vs broadband transmission, noise and signal-to-noise ratio, multiplexing, and provides short notes on communication through the ionosphere and DSB-SC and VSB modulation techniques.
The bandwidth of a signal is defined as the difference between the upper and lower frequencies of the signal. It represents the range of frequencies occupied by the signal and is measured in Hertz (Hz). Different types of signals have different bandwidths. For example, the bandwidth of a voice signal is 300-3400 Hz, while the bandwidth of a music signal is 20-15000 Hz. Bandwidth is calculated differently for analog and digital signals, with analog bandwidth based on frequency and digital bandwidth on bit rate.
Fm transmitter and future radio technologyChima Chukwu
ABSTRACT
FM Transmitter is a device which generates frequency modulated signal. It is
one element of a radio system which, with the aid of an antenna, propagates
an electromagnetic signal. Standard FM broadcasts are based in the 88 - 108
MHz range. Advancements have been made in the way FM is broadcast. This
includes utilizing such technologies as Hybrid Digital (HD) Radio, Software
Defined Radio (SDR) and Cognitive Radio.
HD Radio uses IBOC (In-Band On-Channel) as a methodof broadcasting digital
radio signals on the same FM channel, and at the same time as the
conventional analog signal while Software defined radio (SDR) is the term used
to describe radio technology where some or the entire wireless physical layer
functions are software defined.
Cognitive radio networks on the other hand, are intelligent networks that can
automatically sense the environment and adapt the communication
parameters accordingly. These types of networks have applications in dynamic
spectrum access, co-existence of different wireless networks, interference
management, etc.
Signal Leakage and Ingress at Higher Frequencies, Understanding the Challenge...Cisco Service Provider
Download the full paper here: https://communities.cisco.com/docs/DOC-37010
For more discussions and topics around Service Providers, please visit our SP Community: http://cisco.com/go/serviceprovidercommunity
The document provides an introduction to analog communications. It outlines the course objectives which are to explain communication principles, discuss signal types and characteristics, and differentiate modulation techniques. It then discusses the history of communication systems from the telegraph to the modern internet. The basic components of a communication system including the transmitter, transmission medium, receiver, and their functions are described. Finally, it covers topics such as analog versus digital signals, bandwidth, frequency spectrum, propagation techniques, and decibels.
Application note signal_generator_spectral_purityS.c. Lu
This document discusses spectral purity and its importance for signal generators. It defines spectral purity as the inherent stability of a signal over time. Short-term stability is the greater concern and is affected by noise and fluctuations. The document outlines common ways to measure spectral purity, including single-sideband phase noise and spurious levels. It explains how poor spectral purity in signal generators can negatively impact receiver measurements by obscuring signals or making receivers appear worse than they are. Strict spectral purity is important for applications like testing narrowband receivers and using signal generators as local oscillators.
This document discusses mobile communication and propagation challenges, including short antenna heights and time-varying propagation paths. It then introduces OFDM as a modulation technique that uses channel coding and multiple narrowband subcarriers to solve multipath problems. OFDM allows parallel transmission of data across multiple frequencies to mitigate frequency-selective fading on mobile channels. The document also covers spread spectrum techniques like frequency hopping and direct sequence spread spectrum that make wireless signals resistant to interference and interception by spreading them across a wider frequency band.
This document presents a study on using ultra-wideband (UWB) FM-CW radar to detect human motion inside buildings. It includes sections that provide an introduction to radar technology and different radar types including pulse radar, continuous wave radar, and FM-CW radar. It also discusses UWB radar technology, its features such as high data rates and low power consumption. The document examines applying UWB radar for detecting human motion and describes how UWB signals propagate through different wall materials. It concludes that UWB technology is growing in importance due to its features and applications like imaging systems, radar systems, and sensor networks.
Gujarat Institute of Amateur Radio provides training and resources for amateur ("ham") radio operators. During disasters, ham radio is often the only form of communication when other systems fail. The document outlines ham radio's role in past disasters in India and how it works, including requirements to become a licensed operator and typical communications methods like VHF, HF radio and satellites.
Frequency is the rate of vibration per second, measured in hertz (Hz). Amplitude modulation (AM) is a form of radio transmission where the amplitude of the carrier wave is varied in accordance with the sound wave. AM has advantages like simplicity and low cost but disadvantages like inefficiency and susceptibility to noise. Frequency modulation (FM) varies the frequency of the carrier wave and is more resilient to noise. It is better suited than AM for mobile radio communication and high quality broadcasts. Digital audio broadcasting (DAB) converts audio to a digital signal, allowing better sound quality than analog radio systems.
Frequency is the rate of vibration per second, measured in hertz (Hz). Amplitude modulation (AM) is a form of radio transmission where the amplitude of the carrier wave is varied in accordance with the sound wave. AM has advantages like simplicity and low cost but disadvantages like inefficiency and susceptibility to noise. Frequency modulation (FM) varies the frequency of the carrier wave and is more resilient to noise. It is better suited than AM for mobile radio communication and high quality broadcasts. Digital audio broadcasting (DAB) converts audio to a digital signal, allowing better sound quality than analog radio systems.
This document discusses IBOC (In-Band On-Channel) technology, which allows digital audio broadcasting without requiring new spectrum allocations. IBOC inserts a digital sideband signal within the existing AM and FM bands. There are three modes of IBOC operation: hybrid mode, extended hybrid mode, and all-digital mode. IBOC implementation can use either low-level or high-level combining of FM and IBOC signals. Benefits of digital radio include high quality audio and added services, but adoption has been delayed by issues like interference and costs.
What are the Benefits of LoRaWAN Technology?
Today, we talk about the seven benefits of LoRaWAN technology application.
In December 2021, LoRaWAN officially became the ITU International Standard for Low Power Wide Area Networks and has been endorsed by the International Telecommunication Union (ITU).
LoRaWAN is developed as an open standard and has been widely recognized by the low power wide area network community. The rapid adoption of this standard for global IoT low-power wide-area networks is a testament to its universality.
LoRaWAN is now a very popular LPWA communication standard that uses unlicensed radio spectrum in the ISM (Industrial, Scientific, Medical) band at frequencies ranging from approximately 433 MHz to 868 MHz, 915 MHz (standards vary around the world).
In the IoT connectivity environment, in addition to smart home networking and office space scenarios, many IoT devices will be connected and communicated in remote environments where the new environment will be inaccessible and require power connections due to M2M transmission coverage limitations.
Amateur radio, also known as ham radio, allows for non-commercial wireless communication between operators. It uses radio frequencies to allow for message exchange, experimentation, recreation, contesting and emergency communication. Key frequencies used are short wave bands between 1.8-30 MHz and VHF bands between 144-146 MHz. Ham radio operators communicate through various modes including Morse code, analog voice modes like AM and FM, digital text modes, and image transmission modes. Common equipment used includes HF and VHF transceivers, dipole antennas, and repeaters which retransmit weak signals at higher power to increase their coverage area.
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.
This article introduces the design of the antenna and recommends two tested low-cost PCB antennas. These PCB antennas can be used with Bluetooth Low Energy (BLE) solutions. For the best performance, BLE and BLE 2.4GHz radio frequencies must be correctly matched to their antennas.
A short talk (quasi-lecture, it went overtime...) done by me for my Uni society, introducing what amateur radio is about, with some fun and interesting figures in order to help audience to gain slight insight into the wonderful hobby.
It also shows some other types of radio in order to let people know what exactly radio transmissions are for. Some information are simplified in order to cater normal, general audience.
Some pictures are collected from the Internet, please message me if you think your intellectual property is unrightfully used and is causing you trouble. I will try my best to remove it in the best ability as I could.
- NOMA is a non-orthogonal multiple access technology that can improve spectral efficiency by allowing all users to use all time-frequency resources simultaneously through techniques like power domain multiplexing and successive interference cancellation. However, it increases complexity.
- Full duplex technology aims to allow simultaneous uplink and downlink transmission but faces challenges from strong self-interference. Solutions involve antenna separation and self-interference cancellation.
- OAM uses the orbital angular momentum of electromagnetic waves to create orthogonal channels at the same frequency but faces challenges in application to cellular networks from atmospheric effects.
- Machine learning can optimize 5G across all layers to dynamically improve spectrum efficiency based on conditions.
This document discusses various applications of ham radio. It begins by defining ham radio as a hobby where operators can communicate across long distances without the internet or cell phones by using radio frequencies allocated by the FCC. It then discusses how ham radio is used for emergency communication when other forms of communication fail during disasters. Several digital applications of ham radio are also outlined, including Automatic Packet Reporting System (APRS) for tracking locations, packet radio, Software-Defined Radio (SDR), amateur radio high altitude ballooning, D-STAR digital voice/data protocol, and using ham radio to access the internet. The document provides examples of ham radio use in space, agriculture, and during various emergency situations.
This document provides an overview of the topics to be covered in a course on mobile communications. It discusses the history and basics of mobile communications including transmission medium, standards, usage scenarios, and mobile devices. It also covers modulation techniques, propagation effects, multiple access techniques, cellular system design considerations and challenges. Recommended books are provided to supplement the course material.
1 . introduction to communication systemabhijitjnec
This document provides an introduction to communication systems. It discusses the basic components and elements of a communication system including the input, transmitter, channel, receiver and output. It also covers various modulation techniques used to transmit signals over different types of channels. Finally, it discusses different types of signal propagation including ground waves, sky waves and space waves and how radio frequency spectrum is allocated internationally.
Ham Radio Introduction Texas Country Air Rally Oct 2015Dale Finley
Amateur Radio is a hobby where operators use radio transmitters and receivers to communicate with each other. Hams engage in various activities like emergency communication, technical experimentation, contests, and communicating with astronauts. To get licensed, one must pass an exam to demonstrate knowledge of radio regulations, safety, and electronics. Entry-level licenses allow operating on VHF/UHF bands, while higher licenses provide access to communicating over long distances on the HF bands. A basic station can involve a handheld radio, while more advanced setups include mobile radios, antennas, and home base stations. Local ham radio clubs offer resources for license training and activities.
The document provides a history of the evolution of mobile radio communications. It discusses how mobile radio evolved from early AM systems in the 1930s-1940s with a few thousand users to today's cellular systems with tens of millions of users. Key developments included the introduction of FM modulation in the late 1930s, the conception and development of the cellular concept in the 1960s-1970s to enable wireless communication networks to serve entire populations, and exponential growth in the past decade fueled by technology advances and increased spectrum allocation for cellular.
Signal Leakage and Ingress at Higher Frequencies, Understanding the Challenge...Cisco Service Provider
Download the full paper here: https://communities.cisco.com/docs/DOC-37010
For more discussions and topics around Service Providers, please visit our SP Community: http://cisco.com/go/serviceprovidercommunity
The document provides an introduction to analog communications. It outlines the course objectives which are to explain communication principles, discuss signal types and characteristics, and differentiate modulation techniques. It then discusses the history of communication systems from the telegraph to the modern internet. The basic components of a communication system including the transmitter, transmission medium, receiver, and their functions are described. Finally, it covers topics such as analog versus digital signals, bandwidth, frequency spectrum, propagation techniques, and decibels.
Application note signal_generator_spectral_purityS.c. Lu
This document discusses spectral purity and its importance for signal generators. It defines spectral purity as the inherent stability of a signal over time. Short-term stability is the greater concern and is affected by noise and fluctuations. The document outlines common ways to measure spectral purity, including single-sideband phase noise and spurious levels. It explains how poor spectral purity in signal generators can negatively impact receiver measurements by obscuring signals or making receivers appear worse than they are. Strict spectral purity is important for applications like testing narrowband receivers and using signal generators as local oscillators.
This document discusses mobile communication and propagation challenges, including short antenna heights and time-varying propagation paths. It then introduces OFDM as a modulation technique that uses channel coding and multiple narrowband subcarriers to solve multipath problems. OFDM allows parallel transmission of data across multiple frequencies to mitigate frequency-selective fading on mobile channels. The document also covers spread spectrum techniques like frequency hopping and direct sequence spread spectrum that make wireless signals resistant to interference and interception by spreading them across a wider frequency band.
This document presents a study on using ultra-wideband (UWB) FM-CW radar to detect human motion inside buildings. It includes sections that provide an introduction to radar technology and different radar types including pulse radar, continuous wave radar, and FM-CW radar. It also discusses UWB radar technology, its features such as high data rates and low power consumption. The document examines applying UWB radar for detecting human motion and describes how UWB signals propagate through different wall materials. It concludes that UWB technology is growing in importance due to its features and applications like imaging systems, radar systems, and sensor networks.
Gujarat Institute of Amateur Radio provides training and resources for amateur ("ham") radio operators. During disasters, ham radio is often the only form of communication when other systems fail. The document outlines ham radio's role in past disasters in India and how it works, including requirements to become a licensed operator and typical communications methods like VHF, HF radio and satellites.
Frequency is the rate of vibration per second, measured in hertz (Hz). Amplitude modulation (AM) is a form of radio transmission where the amplitude of the carrier wave is varied in accordance with the sound wave. AM has advantages like simplicity and low cost but disadvantages like inefficiency and susceptibility to noise. Frequency modulation (FM) varies the frequency of the carrier wave and is more resilient to noise. It is better suited than AM for mobile radio communication and high quality broadcasts. Digital audio broadcasting (DAB) converts audio to a digital signal, allowing better sound quality than analog radio systems.
Frequency is the rate of vibration per second, measured in hertz (Hz). Amplitude modulation (AM) is a form of radio transmission where the amplitude of the carrier wave is varied in accordance with the sound wave. AM has advantages like simplicity and low cost but disadvantages like inefficiency and susceptibility to noise. Frequency modulation (FM) varies the frequency of the carrier wave and is more resilient to noise. It is better suited than AM for mobile radio communication and high quality broadcasts. Digital audio broadcasting (DAB) converts audio to a digital signal, allowing better sound quality than analog radio systems.
This document discusses IBOC (In-Band On-Channel) technology, which allows digital audio broadcasting without requiring new spectrum allocations. IBOC inserts a digital sideband signal within the existing AM and FM bands. There are three modes of IBOC operation: hybrid mode, extended hybrid mode, and all-digital mode. IBOC implementation can use either low-level or high-level combining of FM and IBOC signals. Benefits of digital radio include high quality audio and added services, but adoption has been delayed by issues like interference and costs.
What are the Benefits of LoRaWAN Technology?
Today, we talk about the seven benefits of LoRaWAN technology application.
In December 2021, LoRaWAN officially became the ITU International Standard for Low Power Wide Area Networks and has been endorsed by the International Telecommunication Union (ITU).
LoRaWAN is developed as an open standard and has been widely recognized by the low power wide area network community. The rapid adoption of this standard for global IoT low-power wide-area networks is a testament to its universality.
LoRaWAN is now a very popular LPWA communication standard that uses unlicensed radio spectrum in the ISM (Industrial, Scientific, Medical) band at frequencies ranging from approximately 433 MHz to 868 MHz, 915 MHz (standards vary around the world).
In the IoT connectivity environment, in addition to smart home networking and office space scenarios, many IoT devices will be connected and communicated in remote environments where the new environment will be inaccessible and require power connections due to M2M transmission coverage limitations.
Amateur radio, also known as ham radio, allows for non-commercial wireless communication between operators. It uses radio frequencies to allow for message exchange, experimentation, recreation, contesting and emergency communication. Key frequencies used are short wave bands between 1.8-30 MHz and VHF bands between 144-146 MHz. Ham radio operators communicate through various modes including Morse code, analog voice modes like AM and FM, digital text modes, and image transmission modes. Common equipment used includes HF and VHF transceivers, dipole antennas, and repeaters which retransmit weak signals at higher power to increase their coverage area.
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.
This article introduces the design of the antenna and recommends two tested low-cost PCB antennas. These PCB antennas can be used with Bluetooth Low Energy (BLE) solutions. For the best performance, BLE and BLE 2.4GHz radio frequencies must be correctly matched to their antennas.
A short talk (quasi-lecture, it went overtime...) done by me for my Uni society, introducing what amateur radio is about, with some fun and interesting figures in order to help audience to gain slight insight into the wonderful hobby.
It also shows some other types of radio in order to let people know what exactly radio transmissions are for. Some information are simplified in order to cater normal, general audience.
Some pictures are collected from the Internet, please message me if you think your intellectual property is unrightfully used and is causing you trouble. I will try my best to remove it in the best ability as I could.
- NOMA is a non-orthogonal multiple access technology that can improve spectral efficiency by allowing all users to use all time-frequency resources simultaneously through techniques like power domain multiplexing and successive interference cancellation. However, it increases complexity.
- Full duplex technology aims to allow simultaneous uplink and downlink transmission but faces challenges from strong self-interference. Solutions involve antenna separation and self-interference cancellation.
- OAM uses the orbital angular momentum of electromagnetic waves to create orthogonal channels at the same frequency but faces challenges in application to cellular networks from atmospheric effects.
- Machine learning can optimize 5G across all layers to dynamically improve spectrum efficiency based on conditions.
This document discusses various applications of ham radio. It begins by defining ham radio as a hobby where operators can communicate across long distances without the internet or cell phones by using radio frequencies allocated by the FCC. It then discusses how ham radio is used for emergency communication when other forms of communication fail during disasters. Several digital applications of ham radio are also outlined, including Automatic Packet Reporting System (APRS) for tracking locations, packet radio, Software-Defined Radio (SDR), amateur radio high altitude ballooning, D-STAR digital voice/data protocol, and using ham radio to access the internet. The document provides examples of ham radio use in space, agriculture, and during various emergency situations.
This document provides an overview of the topics to be covered in a course on mobile communications. It discusses the history and basics of mobile communications including transmission medium, standards, usage scenarios, and mobile devices. It also covers modulation techniques, propagation effects, multiple access techniques, cellular system design considerations and challenges. Recommended books are provided to supplement the course material.
1 . introduction to communication systemabhijitjnec
This document provides an introduction to communication systems. It discusses the basic components and elements of a communication system including the input, transmitter, channel, receiver and output. It also covers various modulation techniques used to transmit signals over different types of channels. Finally, it discusses different types of signal propagation including ground waves, sky waves and space waves and how radio frequency spectrum is allocated internationally.
Ham Radio Introduction Texas Country Air Rally Oct 2015Dale Finley
Amateur Radio is a hobby where operators use radio transmitters and receivers to communicate with each other. Hams engage in various activities like emergency communication, technical experimentation, contests, and communicating with astronauts. To get licensed, one must pass an exam to demonstrate knowledge of radio regulations, safety, and electronics. Entry-level licenses allow operating on VHF/UHF bands, while higher licenses provide access to communicating over long distances on the HF bands. A basic station can involve a handheld radio, while more advanced setups include mobile radios, antennas, and home base stations. Local ham radio clubs offer resources for license training and activities.
The document provides a history of the evolution of mobile radio communications. It discusses how mobile radio evolved from early AM systems in the 1930s-1940s with a few thousand users to today's cellular systems with tens of millions of users. Key developments included the introduction of FM modulation in the late 1930s, the conception and development of the cellular concept in the 1960s-1970s to enable wireless communication networks to serve entire populations, and exponential growth in the past decade fueled by technology advances and increased spectrum allocation for cellular.
Image processing involves manipulating digital images through algorithms implemented on computers. A digital image is composed of picture elements called pixels arranged in a grid. Each pixel represents a color or intensity value. Common image processing tasks include computer vision, optical character recognition, medical imaging, and more. Key concepts in image processing include pixels, resolution, color depth, and filtering/manipulating pixel values.
This document discusses digital signal processing (DSP). It begins by explaining that DSP involves converting an analog waveform into a series of discrete digital levels by measuring the amplitude of the waveform at regular intervals. It then provides examples of common DSP operations like convolution, correlation, filtering and modulation. The document notes key advantages of DSP like accuracy and reproducibility but also mentions disadvantages like cost and finite word length problems. It concludes by listing some common application areas for DSP like image processing, instrumentation/control, speech/audio processing, and telecommunications.
1) Digital image processing involves improving, restoring, compressing, segmenting, and recognizing digital images. It has applications in industry, medicine, traffic control, entertainment, and more.
2) The origins of digital image processing date back to the 1920s in newspaper printing, but it developed significantly with the space program in the 1960s and medical CT scans in the 1970s.
3) A digital image processing system typically involves image acquisition, storage, processing, and display. Low-level processes improve image quality while mid- and high-level processes extract attributes and recognize objects.
Haptics is a technology that adds the sense of touch to interactions with virtual objects by connecting user movements and actions to corresponding computer-generated feedback such as forces, vibrations, and motions. This allows virtual objects to seem real and tangible to the user. Haptics links the brain's sensing of body position and movement through sensory nerves to provide an immersive experience when interacting with virtual environments and simulated objects.
This presentation provides an overview of embedded systems and describes a collision avoidance robot project. It introduces embedded systems and gives examples. It then describes the key components of embedded systems like processors and memory. It discusses the software used for the project. It introduces the collision avoidance robot project, describing its sensors, control unit, actuators and working. It provides code snippets to show how the robot's movement is controlled based on sensor input to avoid collisions.
The document discusses wireless network design best practices and applications. It covers wireless standards and technologies, including frequency hopping spread spectrum and direct sequence spread spectrum. It also discusses wireless network components, encryption methods, wireless channel selection and characteristics, and common wireless network topologies and solutions.
The document discusses the physical layer of the network protocol stack. It describes how information can be encoded into either analog or digital signals and transmitted over various physical media types, including guided media like twisted pair cables and unguided media like radio waves. It explains concepts like bandwidth, frequency spectrum, and how different physical layer technologies like radio, microwave, and satellite communication work.
Radio waves are used for more than just radio and broadcasting. They enable technologies like WiFi, mobile phones, and television. Radio waves have the longest wavelengths of all electromagnetic waves. AM radio has the longest wavelength and widest coverage but lower quality than FM radio. WiFi uses radio waves to transmit data wirelessly between devices using frequencies of 2.4 GHz or 5 GHz. Mobile phones use cellular networks of radio transmitter towers to connect calls by transmitting low power radio signals. Television receives both video through AM radio signals and sound through either AM or FM radio signals. Radar transmits radio signals that bounce off objects and return to detect their presence and distance. Radio waves play a vital role in modern communication and technologies beyond their initial use
Digital communication systems have several advantages over analog systems:
1) Digital signals can be repeated without amplification, avoiding cumulative noise.
2) Digital error correction allows transmission over longer distances with better data integrity.
3) Digital techniques facilitate higher bandwidth and more efficient multiplexing of multiple signals.
Digital audio broadcasting (DAB) provides CD-quality sound, many station choices, and interference-free reception. It offers advantages over analog FM like high quality audio, error correction, and reduced multipath interference. DAB uses MPEG audio compression and OFDM modulation to transmit multiple signals over a single frequency band. While DAB coverage is still limited compared to FM in many areas, it provides better sound quality and has the potential to become the future of radio broadcasting worldwide as more countries adopt the technology.
This document discusses analog and digital signals and the process of analog-to-digital conversion. It provides examples of analog signals like voice, video and radio frequencies. It then explains how digital signals use binary code and how analog signals must be converted to digital before most modern technology can interpret them. This is done through analog-to-digital converters which sample the analog signal at regular intervals and generate a binary number to represent each sample. As an example, it outlines the recent conversion of television broadcast from analog to digital signals in the United States which provided advantages like more efficient use of bandwidth but also resulted in some viewers losing access without converter boxes.
The document provides an overview of the history and architecture of GSM cellular networks. It discusses the evolution from analog 1G networks to digital 2G and 2.5G networks. The key components of GSM architecture include the BTS, BSC, MSC, HLR, VLR, and AuC. GSM uses TDMA and FDMA to allow multiple users to share the frequency spectrum. It also relies on the SS7 protocol for signaling communication between network components to enable features like roaming.
The document provides an overview of the history and architecture of GSM cellular networks. It discusses the evolution from analog 1G networks to digital 2G and 2.5G networks. The key components of GSM architecture include the BTS, BSC, MSC, HLR, VLR, and AuC. GSM uses TDMA and FDMA to allow multiple users to share the frequency spectrum. It also relies on the SS7 protocol for signaling communication between network components to enable features like roaming.
This document provides an overview of radio frequency (RF) basics for non-RF engineers. It defines common RF terms like dBm and discusses electromagnetic spectrum allocation. It describes the basic building blocks of RF systems including transmitters, receivers, modulation methods, and system types. Key topics covered include amplitude shift keying, frequency shift keying, and phase shift keying digital modulation techniques. The document also reviews RF parameters and measurement equipment.
Introduction to RF & Wireless - Part 1Carl Weisman
The document provides an overview of a two-day seminar on radio frequency (RF) and wireless systems. It includes:
1) A daily schedule with modules on RF hardware, older/newer wireless systems, and the future.
2) An agenda covering introduction to RF, RF hardware on day one, and older/mobile systems and newer technologies on day two.
3) An outline of module one which introduces RF basics, behavior, modulation, and noise. It defines terms, discusses analog/digital signals, and how signals propagate through free space and materials.
In 3 sentences or less, this document summarizes the content and structure of a seminar on RF and wireless systems, including
Radio waves transmit information such as television, internet, and music through invisible electromagnetic waves that are received by antennas and decoded into various media. Radios have a transmitter that encodes sound into sine waves and an antenna that receives the electromagnetic waves. The information is encoded in the wave pattern. Antennas receive thousands of signals at once, requiring tuners to select a particular frequency. Radio waves are used for wireless technologies, TV, phones, and some medical applications. They can travel long distances by following the Earth's curvature. Common radio frequencies include AM/FM and television bands.
The document discusses key concepts in communication systems including:
- Defining analog and digital signals, where analog signals vary continuously and digital signals change in discrete steps.
- The basic elements of a communication system including an information source, transmitter that processes signals for transmission, channel to transmit signals, receiver to extract signals, and output transducer.
- Types of noise that can degrade signals including internal noise from system components and external noise from sources like atmosphere, space, and human activity.
- Physical and technological limitations that constrain communication systems such as bandwidth limitations, noise, and available technologies.
Direct sequence spread spectrum is a technique that spreads signals across a wider bandwidth through the use of pseudorandom number sequences. This decreases interference and allows multiple access and functions. In direct sequence spread spectrum, each bit is represented by multiple bits using a spreading code, spreading the signal across a wider frequency band proportional to the number of bits. It is used in applications like GPS, wireless networks, and communications to increase resistance to interference and jamming while allowing sharing of channels.
The document discusses Wi-Fi technologies. It describes the 802.11 family of specifications including 802.11, 802.11a, 802.11b and 802.11g. It explains that 802.11 established the original wireless LAN standard, while 802.11a supports speeds up to 54 Mbps in the 5GHz band. 802.11b, also known as Wi-Fi, supports speeds up to 11 Mbps in the 2.4GHz band. Finally, 802.11g operates in the same frequency band as 802.11b but supports speeds over 20 Mbps.
Wireless Sensor Networks: Nothing is Out of ReachEnergySec
Presenter: Daniel Lance, Layered Integration
After years of installing wireless sensor networks in homes and businesses we are now faced with a question “How is this all secure? Or is it?” A look into WSN (Wireless Sensor Networks) history and original design concepts that paved the road to us using these in our every day life.
This presentation will be a deep dive into wireless and reveal new challenges we have in protecting our perimeter when all of our core monitoring devices are riding a wave into the public space as most industrial control providers look to capitalize on fast installation times and inexpensive adaptive solutions. This research shows us start to finish how anyone with a laptop and SDR (Software Defined Radio) can hack into and take control of WSN’s from outside the front gate.
The presentation will demonstrate how a device inside your facility might reveal itself through spectrum analysis than how a hacker might flank the security of the device and own the network with very simple replay attacks that can grant them physical access, and how social engineering pre-installation and post-installation will cause you to disregard warning signs that someone is tampering with the network. A high level understanding of radio is no longer needed for packet analysis with open source tools, proper implementation has never been more important as even a encrypted device can be compromised by the last mile before installation. We will talk about the tools security professionals are lacking from the manufactures of these devices to scan for a compromised device and what can be done in the future to protect WSN’s.
Wireless# Guide to Wireless CommunicationsChapter 3Und.docxambersalomon88660
Wireless# Guide to Wireless Communications
Chapter 3
Understanding Radio Frequency Communications
Wireless# Guide to Wireless Communications
ObjectivesList the components of a radio systemDescribe how different factors affect the design of a radio systemDiscuss why standards are beneficial and list the major telecommunications standards organizationsExplain the radio frequency spectrum
Wireless# Guide to Wireless Communications
Components of a Radio SystemComponents include:FiltersMixersAmplifiersAntennas
Wireless# Guide to Wireless Communications
FiltersFilterRemoves unwanted RF signalsRF filterEither passes or rejects a signal based on frequencyTypes of filtersLow-pass filterHigh-pass filterBandpass filter
Wireless# Guide to Wireless Communications
Filters (continued)
Wireless# Guide to Wireless Communications
Filters (continued)Filters are also found in transmittersUsed to eliminate some unwanted frequenciesThat result from the process of modulating the signal before transmissionIntermediate frequency (IF) signalResulting output from the modulation processIF signal is filtered through a bandpass filterTo remove any undesired high- or low-frequency signals
Wireless# Guide to Wireless Communications
Filters (continued)
Wireless# Guide to Wireless Communications
MixersCombine two radio frequency inputs to create a single outputOutput is in the range of the highest sum and the lowest difference of the two frequenciesSum and differences are known as the sidebands of the frequency carrierShield transmitted signal from “stray” signalsUsed to convert an input frequency to a specific desired output frequency
Wireless# Guide to Wireless Communications
Mixers (continued)
Wireless# Guide to Wireless Communications
Mixers (continued)
Wireless# Guide to Wireless Communications
AmplifiersIncrease the amplitude of an RF signalRF signals tend to lose intensity (amplitude)When they move through circuits, air, or spaceAmplifier is an active deviceMust be supplied with electricityIncreases a signal’s intensity or strengthBy using the input signal to control a circuit that “shapes” the outputTo reflect the shape of the input signal exactly
Wireless# Guide to Wireless Communications
Amplifiers (continued)
Wireless# Guide to Wireless Communications
AntennasTransmit or receive an RF signal
Wireless# Guide to Wireless Communications
Antennas (continued)
Wireless# Guide to Wireless Communications
Design of a Radio SystemDesigners of radio communications systems Need to consider how the systems will be used
Wireless# Guide to Wireless Communications
Multiple AccessOnly a limited number of frequencies are available for radio transmissionConserving the use of frequencies is importantConserving a frequencyShare a frequency among several individual usersMethods that allow multiple accessFrequency Division Multiple Access (FDMA)Time Division Multiple Access (TDMA)Code Division Mult.
Radiowaves are a type of electromagnetic radiation that travel at the speed of light, making them ideal for long-distance communications. They are used for radio broadcasting, telephones, televisions, Wi-Fi, and navigation technologies like GPS and radar. Radio broadcasting has evolved from AM to FM to digital formats. Telephones and televisions both use radio waves to transmit sound and images wirelessly. Wi-Fi networks convert digital data to radio signals that routers and devices can transmit and receive to connect to the internet without wires. GPS and radar technologies also use radio waves to determine locations and detect objects from a distance.
Radio has made a comeback in India due to technology allowing for private players and foreign investment. Radio broadcasting uses different technologies like AM, FM, and satellite. FM radio provides higher quality sound and additional channels. HD radio allows digital broadcasting of AM and FM stations. Internet radio provides streaming audio worldwide. The history of radio involved many pioneers and the development of technologies like wireless telegraphy, AM, FM, and digital broadcasting standards. Radio broadcasting grew from wireless telegraphy to include entertainment and became a mainstream mass media technology.
A PowerPoint presentation covering the main headings to use in a police report: Source of Activity, Observations, Arrest
Booking, Medical Treatment, Evidence, Suspect Statements, Witness Statements, Victim Statements, Evidence, Property Taken, Injuries, Use of Force, Supplemental Charges, Additional Information. For police, law enforcement and private security personnel.
The concept of YouTube for the Criminal Justice Educator is the provide instructors with dynamic access to supplemental material via video. Nearly 400 videos are categorized and descriptions provided. The links are live from this document. The videos are classified into the nineteen categories. There is some overlap between the categories. The category titles are linked from the Table of Contents. Thus, if you want to view films on Active Shooter, click on Active Shooter in the Table of Contents and you will be taken to that page.
Cops are constantly adapting their equipment to the environment. Our kit bags have grown larger and larger as we collected equipment to deal with the job. Our departments gives us the basics and as we face new situations we think about what we could have used as a tool to have made the task easier. Then, we go out and get that tool – for next time. Much of the commercially produced police equipment used by our peers today was developed “on the fly” by those who walked the beat before us. The concept of the cruiser as a mobile office was developed by those of us who worked long shifts and thought “What could be added to this car to make my job easier? Make me more comfortable? Help me to hunt down dangerous offenders?”
The document discusses the development and benefits of the National Incident Management System (NIMS), which standardized the command and control structure used across different emergency response agencies. It describes how NIMS was created based on lessons learned from major disasters where uncoordinated responses hampered effectiveness. NIMS incorporates the Incident Command System (ICS), which establishes clear leadership and roles through concepts like unified command. ICS allows the response structure to flexibly expand based on the size and needs of the incident. This modular system is designed to improve coordination and save lives.
I use this PowerPoint presentation when working with my clients overseas. It helps to establish my point of view as well as open a conversation on the differences between their models of policing and the typical American experience.
A brief introduction to the federal court system. Excellent presentation for undergraduate introduction to criminal justice courses. Parts 2 through 4 to be uploaded soon.
The document discusses traditional methods of uniformed patrol such as random routine patrol, rapid response to 911 calls, and retroactive investigation of crimes. It summarizes a landmark study in Kansas City that found random patrols had no effect on crime rates, response times, or public perception of safety. The study challenged common assumptions that more police presence deters crime. Alternative patrol strategies are proposed such as directed patrol, split-force models, and differentiating emergency response levels.
The third in a series of PowerPoint presentation on public policy analysis and decision making. While focusing on criminal justice is applicable to all government fields. The material is geared toward an elective course in Master's Program, or upper division in related government courses.
A PowerPoint presentation on decision making in public policy. While the presentation focuses on criminal justice, it applies to all government fields.
A PowerPoint presentation on public policy analysis and decision making. The presentation focuses on criminal justice, but is applicable in all government fields. Lastly, this presentation is part one of three.
This document discusses concepts related to leadership and influence. It begins with definitions of leadership as the art of influencing human behavior toward organizational goals. It then explores various aspects of leadership such as it being an art, the range of influence, focusing on human behavior, and directing behavior toward goals. The document provides examples and analogies to poker to illustrate leadership concepts such as watching human behavior, leading by example, integrity, and innovation. It also discusses the importance of failure, communication, empowerment, vision, determination in the face of adversity, and life-long learning.
This document discusses emerging and future technologies that may be applied in law enforcement. It explores techniques used by futurists to predict technological developments and various applications including emergency location systems, automatic collision notification, universal product coding, radio frequency chipping of goods, biometric identification, satellite surveillance, pursuit technologies using vehicle disabling chips, less-lethal weapons, mobile access to databases, and combinations of technologies. The goal is to understand how future technologies could impact policing.
The document discusses major incident and disaster response, including the Incident Command System (ICS) used to coordinate multi-agency emergency responses. ICS establishes a clear chain of command and modular organizational structure. A key aspect is the Incident Command Post, which is the on-site command center, and the Emergency Operations Center, which coordinates response on a wider scale from a centralized location. The document outlines the roles and responsibilities of first responders in major incidents and disasters, and how technology can enhance response efforts through mobile command vehicles and specialized equipment.
This document discusses crime analysis and its applications in community-oriented policing. Crime analysis involves understanding crime patterns through statistical analysis and crime mapping to identify problems and potential solutions. It helps police departments target areas with high crime rates or unusual increases in crime. Crime analysis also examines relationships between crimes in terms of time, location, offender characteristics, and causal factors to aid investigations of serial crimes and displacement. The core functions of law enforcement like prevention, investigation, and apprehension can be enhanced through crime analysis.
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[To download this presentation, visit:
https://www.oeconsulting.com.sg/training-presentations]
This PowerPoint compilation offers a comprehensive overview of 20 leading innovation management frameworks and methodologies, selected for their broad applicability across various industries and organizational contexts. These frameworks are valuable resources for a wide range of users, including business professionals, educators, and consultants.
Each framework is presented with visually engaging diagrams and templates, ensuring the content is both informative and appealing. While this compilation is thorough, please note that the slides are intended as supplementary resources and may not be sufficient for standalone instructional purposes.
This compilation is ideal for anyone looking to enhance their understanding of innovation management and drive meaningful change within their organization. Whether you aim to improve product development processes, enhance customer experiences, or drive digital transformation, these frameworks offer valuable insights and tools to help you achieve your goals.
INCLUDED FRAMEWORKS/MODELS:
1. Stanford’s Design Thinking
2. IDEO’s Human-Centered Design
3. Strategyzer’s Business Model Innovation
4. Lean Startup Methodology
5. Agile Innovation Framework
6. Doblin’s Ten Types of Innovation
7. McKinsey’s Three Horizons of Growth
8. Customer Journey Map
9. Christensen’s Disruptive Innovation Theory
10. Blue Ocean Strategy
11. Strategyn’s Jobs-To-Be-Done (JTBD) Framework with Job Map
12. Design Sprint Framework
13. The Double Diamond
14. Lean Six Sigma DMAIC
15. TRIZ Problem-Solving Framework
16. Edward de Bono’s Six Thinking Hats
17. Stage-Gate Model
18. Toyota’s Six Steps of Kaizen
19. Microsoft’s Digital Transformation Framework
20. Design for Six Sigma (DFSS)
To download this presentation, visit:
https://www.oeconsulting.com.sg/training-presentations
Starting a business is like embarking on an unpredictable adventure. It’s a journey filled with highs and lows, victories and defeats. But what if I told you that those setbacks and failures could be the very stepping stones that lead you to fortune? Let’s explore how resilience, adaptability, and strategic thinking can transform adversity into opportunity.
Part 2 Deep Dive: Navigating the 2024 Slowdownjeffkluth1
Introduction
The global retail industry has weathered numerous storms, with the financial crisis of 2008 serving as a poignant reminder of the sector's resilience and adaptability. However, as we navigate the complex landscape of 2024, retailers face a unique set of challenges that demand innovative strategies and a fundamental shift in mindset. This white paper contrasts the impact of the 2008 recession on the retail sector with the current headwinds retailers are grappling with, while offering a comprehensive roadmap for success in this new paradigm.
The Steadfast and Reliable Bull: Taurus Zodiac Signmy Pandit
Explore the steadfast and reliable nature of the Taurus Zodiac Sign. Discover the personality traits, key dates, and horoscope insights that define the determined and practical Taurus, and learn how their grounded nature makes them the anchor of the zodiac.
[To download this presentation, visit:
https://www.oeconsulting.com.sg/training-presentations]
This presentation is a curated compilation of PowerPoint diagrams and templates designed to illustrate 20 different digital transformation frameworks and models. These frameworks are based on recent industry trends and best practices, ensuring that the content remains relevant and up-to-date.
Key highlights include Microsoft's Digital Transformation Framework, which focuses on driving innovation and efficiency, and McKinsey's Ten Guiding Principles, which provide strategic insights for successful digital transformation. Additionally, Forrester's framework emphasizes enhancing customer experiences and modernizing IT infrastructure, while IDC's MaturityScape helps assess and develop organizational digital maturity. MIT's framework explores cutting-edge strategies for achieving digital success.
These materials are perfect for enhancing your business or classroom presentations, offering visual aids to supplement your insights. Please note that while comprehensive, these slides are intended as supplementary resources and may not be complete for standalone instructional purposes.
Frameworks/Models included:
Microsoft’s Digital Transformation Framework
McKinsey’s Ten Guiding Principles of Digital Transformation
Forrester’s Digital Transformation Framework
IDC’s Digital Transformation MaturityScape
MIT’s Digital Transformation Framework
Gartner’s Digital Transformation Framework
Accenture’s Digital Strategy & Enterprise Frameworks
Deloitte’s Digital Industrial Transformation Framework
Capgemini’s Digital Transformation Framework
PwC’s Digital Transformation Framework
Cisco’s Digital Transformation Framework
Cognizant’s Digital Transformation Framework
DXC Technology’s Digital Transformation Framework
The BCG Strategy Palette
McKinsey’s Digital Transformation Framework
Digital Transformation Compass
Four Levels of Digital Maturity
Design Thinking Framework
Business Model Canvas
Customer Journey Map
How MJ Global Leads the Packaging Industry.pdfMJ Global
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Taurus Zodiac Sign: Unveiling the Traits, Dates, and Horoscope Insights of th...my Pandit
Dive into the steadfast world of the Taurus Zodiac Sign. Discover the grounded, stable, and logical nature of Taurus individuals, and explore their key personality traits, important dates, and horoscope insights. Learn how the determination and patience of the Taurus sign make them the rock-steady achievers and anchors of the zodiac.
Zodiac Signs and Food Preferences_ What Your Sign Says About Your Tastemy Pandit
Know what your zodiac sign says about your taste in food! Explore how the 12 zodiac signs influence your culinary preferences with insights from MyPandit. Dive into astrology and flavors!
The APCO Geopolitical Radar - Q3 2024 The Global Operating Environment for Bu...APCO
The Radar reflects input from APCO’s teams located around the world. It distils a host of interconnected events and trends into insights to inform operational and strategic decisions. Issues covered in this edition include:
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1. Copyright Protected 2005: Hi Tech Criminal Justice, Raymond E. Foster
Police TechnologyPolice Technology
Chapter ThreeChapter Three
WirelessWireless
CommunicationsCommunications
2. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Learning ObjectivesLearning Objectives
Basic radio wave theoryBasic radio wave theory
AnalogAnalog andand digitaldigital communicationscommunications
Basic parts of radio frequency communicationsBasic parts of radio frequency communications
Digital communications; includingDigital communications; including
Time Division Multiple Access (TDMA)Time Division Multiple Access (TDMA)
Frequency Division Multiple Access (FDMA)Frequency Division Multiple Access (FDMA)
Code Division Multiple Access (CDMA)Code Division Multiple Access (CDMA)
Cellular Digit Packet Data (CDPD)Cellular Digit Packet Data (CDPD)
Cellular telephone systemsCellular telephone systems
3. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Radio BasicsRadio Basics
There are two medias for the transmissionThere are two medias for the transmission
of electronic information:of electronic information:
Information can be transmitted over aInformation can be transmitted over a
wirewire, like telephone conversations., like telephone conversations.
It can be transmitted through theIt can be transmitted through the
atmosphere;atmosphere; wirelesswireless like the signals yourlike the signals your
car radio receives.car radio receives.
4. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Radio BasicsRadio Basics
Wireless communicationWireless communication
hashas
an advantage overan advantage over
hardwired communicationshardwired communications
Wireless can beWireless can be
broadcast over a widebroadcast over a wide
area and to a largearea and to a large
number of users.number of users.
Because wirelessBecause wireless
communication usescommunication uses
radio frequencies, it isradio frequencies, it is
often referred to asoften referred to as RFRF
communicationcommunication
5. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Radio BasicsRadio Basics
Radio waves are the way inRadio waves are the way in
which both analog and digitalwhich both analog and digital
signals are carried assignals are carried as
wireless Communications.wireless Communications.
Voice and data informationVoice and data information
can be carried by either.can be carried by either.
Both have advantages andBoth have advantages and
disadvantages.disadvantages.
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Analog radio system consists of aAnalog radio system consists of a
microphone that modulates (changes) themicrophone that modulates (changes) the
human voice to an analog wave, which ishuman voice to an analog wave, which is
processed and sent to anprocessed and sent to an antennaantenna forfor
transmission. The return signal is passedtransmission. The return signal is passed
through the antenna to be received,through the antenna to be received,
processed, and broadcast out a speakerprocessed, and broadcast out a speaker
Radio BasicsRadio Basics
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Radio BasicsRadio Basics
An analog radio system can carryAn analog radio system can carry
digital signals, but first the digitaldigital signals, but first the digital
signal must be converted from itssignal must be converted from its
analog configuration to aanalog configuration to a
digital configuration.digital configuration.
This is accomplished by aThis is accomplished by a
modulator-demodulator unit, amodulator-demodulator unit, a
modemmodem..
For this transmission scheme toFor this transmission scheme to
work, both the sender and receiverwork, both the sender and receiver
must have a modem.must have a modem.
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As you move further awayAs you move further away
from the antenna that isfrom the antenna that is
broadcasting an analogbroadcasting an analog
signal, the signal becomessignal, the signal becomes
weaker until the strength ofweaker until the strength of
the signal is lost inthe signal is lost in
background static andbackground static and
the transmission cannotthe transmission cannot
be heard.be heard.
Radio BasicsRadio Basics
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Radio BasicsRadio Basics
A digital signal can be broadcast only upA digital signal can be broadcast only up
to a certain distance.to a certain distance.
Once that distance is reached, the signalOnce that distance is reached, the signal
for transmission is gonefor transmission is gone
10. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Radio BasicsRadio Basics
Radio signals travel in waves (like soundRadio signals travel in waves (like sound
and light). Radio waves are like ripplesand light). Radio waves are like ripples
in a pond with two important differences:in a pond with two important differences:
You cannot see radio waves. They areYou cannot see radio waves. They are
invisible; and,invisible; and,
Radio waves stay constant. They do notRadio waves stay constant. They do not
distant themselves (grow further apart).distant themselves (grow further apart).
11. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Radio BasicsRadio Basics
Radio waves travel in a constant
pattern. The number of wave cycles
per second is called a Hertz, or more
commonly the radio frequency.
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Radio BasicsRadio Basics
AM/FM radios work inAM/FM radios work in
ranges that areranges that are
different from eachdifferent from each
other.other.
These ranges ofThese ranges of
frequencies are calledfrequencies are called
bandsbands..
Different frequencyDifferent frequency
bands share certainbands share certain
broadcastbroadcast
characteristics.characteristics.
13. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Different groups of frequencies are calledDifferent groups of frequencies are called
channelschannels..
The number of frequencies in a channel isThe number of frequencies in a channel is
referred to as the channel’sreferred to as the channel’s bandwidthbandwidth..
The more bandwidth, the more information aThe more bandwidth, the more information a
channel can handle.channel can handle.
AA guard bandguard band prevents the channels fromprevents the channels from
overlapping and confusing the informationoverlapping and confusing the information
exchange.exchange.
Radio BasicsRadio Basics
14. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Effective radiated powerEffective radiated power – how far away– how far away
from the source a signal can be receivedfrom the source a signal can be received
and interpreted.and interpreted.
Lower frequencyLower frequency == Higher effectiveHigher effective
radiated powerradiated power
Radio BasicsRadio Basics
15. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Radio BasicsRadio Basics
Wireless signals sent in aWireless signals sent in a Very HighVery High
Frequency (VHF)Frequency (VHF) - many wave cycles per- many wave cycles per
second - provide a wider area ofsecond - provide a wider area of
coverage.coverage.
Shorter wavelengths ofShorter wavelengths of Ultra HighUltra High
Frequency (UHF)Frequency (UHF) – even more cycles per– even more cycles per
second - go through building windowssecond - go through building windows
better than VHF.better than VHF.
16. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Frequencies within a band share aFrequencies within a band share a
propensity topropensity to skipskip. Skip occurs when a. Skip occurs when a
broadcast reflects off the Earth’sbroadcast reflects off the Earth’s
ionosphere.ionosphere.
Noise and interference more of a problemNoise and interference more of a problem
for lower frequencies (like AM radio)for lower frequencies (like AM radio)
The larger the frequency, the larger theThe larger the frequency, the larger the
antenna required.antenna required.
Radio BasicsRadio Basics
17. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Communications HardwareCommunications Hardware
BasicsBasics
TransmitterTransmitter - generates radio wave- generates radio wave
(the signal)(the signal)
ReceiverReceiver - receives signal, changes it- receives signal, changes it
back into the original formback into the original form
TransceiverTransceiver - combination of both- combination of both
18. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Job of transmitter is to generate the signal.Job of transmitter is to generate the signal.
That frequency is a series of oscillatingThat frequency is a series of oscillating
waves.waves. OscillationOscillation means the waves peakmeans the waves peak
and valley in a predictable and uniformand valley in a predictable and uniform
manner.manner.
The part of the transmitter that generatesThe part of the transmitter that generates
these waves is thethese waves is the oscillatoroscillator..
Communications HardwareCommunications Hardware
BasicsBasics
19. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
To transmit data we use theTo transmit data we use the
Frequency Shift Key (FSK)Frequency Shift Key (FSK) method –method –
two separate frequencies are used totwo separate frequencies are used to
represent ones and zeros of binary data.represent ones and zeros of binary data.
To change voice into digital we use aTo change voice into digital we use a
voice coder (vocoder)voice coder (vocoder) – the reverse of a– the reverse of a
modem.modem.
Communications HardwareCommunications Hardware
BasicsBasics
20. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Different antennas have differentDifferent antennas have different
propagation characteristics (the waypropagation characteristics (the way
the antenna sends out the signal.the antenna sends out the signal.
Basic antenna is a dipole (straight wireBasic antenna is a dipole (straight wire
or metal).or metal).
Communications HardwareCommunications Hardware
BasicsBasics
21. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Communications HardwareCommunications Hardware
BasicsBasics
You can increase the rangeYou can increase the range
of transmission by adjustingof transmission by adjusting
thethe gain -gain - directing thedirecting the
antenna’s radiating energyantenna’s radiating energy
in alternate directions.in alternate directions.
22. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Simple Voice (simplex system)Simple Voice (simplex system) - Users- Users
transmit and receive information on atransmit and receive information on a
single channel or frequency.single channel or frequency.
Repeater SystemRepeater System – The signal is picked– The signal is picked
up by a repeating antenna and repeatedup by a repeating antenna and repeated
at a higher point and on another frequencyat a higher point and on another frequency
to base.to base.
Trunked Radio SystemTrunked Radio System – locates an empty– locates an empty
line and assigns it to the user for theline and assigns it to the user for the
duration of the transmissionduration of the transmission
Radio Frequency SystemsRadio Frequency Systems
23. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Frequency Division MultipleFrequency Division Multiple
AccessAccess
Increases spectrum efficiencyIncreases spectrum efficiency
Typical frequency of 30 kHz is dividedTypical frequency of 30 kHz is divided
into three channels of 10 kHz each.into three channels of 10 kHz each.
Increases the number of frequenciesIncreases the number of frequencies
that can be used in conjunction with athat can be used in conjunction with a
trunked radio system.trunked radio system.
24. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
TDMA takes advantage of the spaceTDMA takes advantage of the space
between words.between words.
Each user is allowed a small portion of theEach user is allowed a small portion of the
broadcast cycle.broadcast cycle.
Timed to not interfere with each other.Timed to not interfere with each other.
Time Division Multiple AccessTime Division Multiple Access
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Code Division Multiple AccessCode Division Multiple Access
In CDMA, each transmission of digitalIn CDMA, each transmission of digital
information isinformation is spread outspread out among all of theamong all of the
available channels.available channels.
The digital frames move from oneThe digital frames move from one
frequency to the next in milliseconds.frequency to the next in milliseconds.
The frames must be put back togetherThe frames must be put back together
with a unique code (direct sequence) towith a unique code (direct sequence) to
each call.each call.
26. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Cellular TechnologyCellular Technology
Cell SiteCell Site – a physical– a physical
location that containslocation that contains
a cellular telephonea cellular telephone
antenna array and aantenna array and a
base stationbase station
controller.controller.
CellCell is the area ofis the area of
coverage provided bycoverage provided by
the cell site antennathe cell site antenna
array.array.
27. Copyright Protected 2005: Hi Tech Criminal Justice, Raymo
Cellular TechnologyCellular Technology
The configuration of cell sites has some ofThe configuration of cell sites has some of
the same characteristics of the repeaterthe same characteristics of the repeater
antenna configuration.antenna configuration.
A primary characteristic that identifies aA primary characteristic that identifies a
cellular system iscellular system is frequency reusefrequency reuse..
A primary characteristic of cellularA primary characteristic of cellular
technology is the ability hand signals offtechnology is the ability hand signals off
from cell to cell.from cell to cell.
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Cellular Digit Packet DataCellular Digit Packet Data
CDPD is a data networkCDPD is a data network, no voice., no voice.
It has an IP address, not a telephone #It has an IP address, not a telephone #
Information from a CDPD system isInformation from a CDPD system is
relayed like a cellular telephone callrelayed like a cellular telephone call
through a commercial carrier.through a commercial carrier.
The subscriber pays only for theThe subscriber pays only for the
packets of data sent over the networkpackets of data sent over the network
29. Copyright Protected 2005: Hi Tech Criminal Justice, Raymond E. Foster
Police TechnologyPolice Technology
Go to theGo to the Student ResourcesStudent Resources
page atpage at
www.hitechcj.comwww.hitechcj.com