Extron

Gooseneck Microphone

· A mic stand designed to capture spoken words limited to the speaker, commonly found on podiums or in conference rooms and boardrooms.

Boundary Microphone

· A small mic capsule mounted flush with a surface, on the floor of a stage, a table in a conference room, or a lectern.

Tree Topology

Also known as a hybrid star bus topology, joins multiple star topologies into a bus. Workstations are connected directly to a tree bus, that act as the root for a tree of devices. This environment used in WAN systems support network scalability more so than just a bus or a star topology.

Refraction

A change in the direction of waves as they pass through an object

Headset Microphone

A lavalier that brings the mic element closer to the mouth for broadcasting and on-stage lecture presentations.

Compression

A region of high pressure where particles are close together

Component YUV

A system that defines color via one luminance value and two color-difference chrominance signals. YPbPr separates the brightness and color into three signals: Y - Luminance (brightness) Pb - Color difference between blue and luma (color) Pr - Color difference between red and luma (color)

Sound

A type of kinetic energy that refers to the vibrations caused by a source. These vibrations propagate as sound waves, traveling through the air or other medium (solid, liquid).

Mesh Topology

A type of point-to-point system where each device is connected directly to all other network devices. This provides fault tolerance in the event of failure so that the network is still reachable and devices can communicate. Given the backup capabilities, mesh networks used in LAN, WLAN and VLAN systems are expensive and difficult to scale.

Compression

A way to alleviate bandwidth requirements is to reduce the amount of video signal data.

Infrared (IR)

A wireless one-way communication interface is designed to only control a single device.

ATSC

Advanced Television Systems Committee. ATSC established technical standards for HDTV that supports video resolutions of 720p and 1080i.

Lavalier Microphone

Allow for hands-free operation typically used in television, theatre, and public speaking. Also known as a lav, clip mic, body mic, collar mic, or personal mic.

RS-422

An improved version of RS-232, by using twisted pair cable to reduce noise, and signal balancing to transmit data longer distances with faster data rates.

Electronic Industries Alliance - EIA

An international industry association that is best known for publishing electrical wiring and transmission standards.

Institute of Electrical and Electronics Engineers - IEEE

An international society composed of engineering professionals that promote the development and education of electronics, computers, and networking. The IEEE 802 branch develops networking practices such as Ethernet, while the 802.11 standard supports Wi-Fi technology.

Analog Signals

As signals experience drops in voltage levels due to cable resistance or capacitance, analog devices provide signal amplification and sharpness enhancement features, such as fixed or variable peaking and gain.

RGBS

Carries RGB separately, combines horizontal and vertical sync signals into what is called composite sync.

RGsB

Carries RGB separately, combines sync to Green signal.

Information Technology Industry Council - ITIC

Comprised of several dozen companies in the IT industry that develops and processes standards for many computer-related topics.

EDID (Extended Display Identification Data)

Contains information about a display's supported features and capabilities. It enables a device to know what kind of monitor is connected, by providing the name, ID number, model number, serial number, display size, aspect ratio, and other information.

Digital Light Processing

DLP technology uses tiny mirrors to represent a single pixel, and a spinning color wheel to create an image.

Composite Video

Delivers standard definition video at a resolution of 480i or 576i. The video information combines the complete video signal and Sync into one channel.

Bus Topology

Devices are connected to a common medium used for communication. Each system is daisy-chained (connected one right after the other) where device information travels along the backbone until it reaches its destination.

EDID

Extended Display Identification Data

Application Layer 7

FTP, HTTP, DNS

Ceiling Microphone

Flush mount or hanging ceiling mics offer directional pickup that delivers clear, intelligible audio without cluttering tabletops.

Presentation Layer 6

Handles the presentation of data when sent from one system, but needs to be viewed differently by other systems. Translations for connecting different types of computers together, compression, and decompression to improve throughput of data, encryption ensures data security as it travels down the protocol stack.

Physical Layer 1

Hardware specifications, encoding and signaling, transmission and reception, topology and physincal network design.

Amplitude

Height of a wave

Handheld Microphone

Held in the hand while picking up sound in a variety of settings, on concert stages or a field reporter.

Subnet Mask

Hides, or "masks," the network part of a system's IP address and leaves only the host part as the device identifier.

HDCP

High bandwidth Digital Content Protection. Implemented by Digital Rights Management (DRM) to prevent unauthorized copying of protected content. This encryption protocol is applied between video sources and displays.

InterNational Committee for Information Technology Standards

INCITS is a committee established by the ITIC to develop and maintain standards related to the IT world.

Gain

Increases the voltage (amplitude) level of an analog signal at the beginning of a long cable run. Measured in decibels (db), gain controls can double or triple a signal's level by providing sufficient voltage to carry the signal to its destination.

Color Bit Depth

Indicates the number of bits used to represent the color value of a single pixel.

ARP

Lies between layers 2 and 3 as a protocol for translating network layer addresses into link layer addresses.Resolves IP addresses to MAC addresses.

Network Layer 3

Logical IP addressing, DNS, FQDN, WINS, routing, datagram encapsulation, error handling and diagnostic.

Data Link Layer 2

Logical link control (LLC), Media access control (MAC), data framing, error detection, cyclic redundancy check, VLAN tagging, CRC.

Resolution

Measures the image size as width x height, in pixels. For example, a resolution of 640x480, indicates the width is 640 pixels and the height is 480 pixels.

MAC Address

Media Access Control. Unique 48-bit identifiers expressed as a 12-digit hexadecimal numbers, separated by dashes or colons. Burned In Address - BIA. The first six digits are the manufacturer's registered ID number, and the remaining digits represent the unique number for that device.

NTSC

National Television Systems Committee. NTSC parameters deliver 525 lines at 60 Hz (60 interlaced fields, or 30 frames per second).

MDX-I

Network interface that automatically detects the type of Ethernet cable being used (straight through, or crossover). The port will alter to make the connection based on the interface detection.

LCD Projectors

Passes a beam of white light to three mirrors that reflect red, blue, and green signals to an LCD panel. The pixels are arranged and combined in a prism to create a single image.

Layer 5 Session

Persistent logical linking of two software application processes, to allow them to exchange data over a prolonged period of time.

Progressive Scanning

Presents moving images by drawing each line sequentially from left to right. A full image frame is created in one pass from top to bottom.

International Organization for Standardization - ISO

Promotes worldwide standards for manufactured products and technology.

Network Access Control - NAC

Provides an authentication and authorization mechanism utilizing IEEE 802.1x and LDAP. These protocols allow authorized devices to access network resources when connected to a network. The NAC may employ switches, routers, and additional software or hardware, client and server to ensure the network is secure before allowing communication between devices.

Transport Layer 4

RTP, RTSP, RTMP.

RS-485

Supports similar data rates as RS-422, but allows up to 32 devices to communicate through the same data line.

RGBHV

Red, Green, Blue signals carry individual colors for each pixel, with separate horizontal and vertical sync signals. Video Graphics Array - VGA are 15-pin connectors that carry RGBHV signals.

Reclocking

Restores the amplitude, rise and fall times, and clock rate attributes of a digital signal, and can also add a small amount of time delay to regain its original shape.

S-Video

Separates the luminance (Y) and chrominance (C) color signals into two separate channels to carry video at 480i or 576i resolution.

Switch

Serves as a controller. Through information sharing and resource allocation as a Layer 2 function, switches allow several users to send information simultaneously with minimal delay.

Line Drivers

Signal amplifiers that drive video, computer graphics, and stereo audio over extended distances.

SMPTE

Society of Motion Picture & Television Engineers

Absorption

Some or all the waves are stopped within the material

Diffraction

Sound waves bending around an object

Reflection

Sound waves hitting a surface and bouncing off

Wiring Pinouts

T568B to T568B cables send signals "straight through" for connecting devices of different types, such as a computer to a network switch. If one side of the cable is T568A and the other is T568B, this is a crossover cable most often used to connect two devices of the same type, such as two computers. Most computer network ports support Auto MDI-X to auto-detect the correct wiring.

User Datagram Protocol (UDP)

The User Datagram Protocol provides connectionless data transfer without error detection and correction.

Router

The bridge that connects remote networks or different subnets. By linking the communication between subnets and across different networks as a Layer 3 function, routers are able determine the next network hop in which a packet is forwarded to its destination.

Telecommunications Industry Association - TIA

The communications sector of the EIA, and is responsible for developing communications standards.

Aspect Ratio

The comparison of an image's width to its height. The ratio is denoted in units of measure as opposed to exact pixels. For instance, a 4:3 ratio measures 4 units wide and 3 units in height.

Wavelength

The distance from the peak of one light or sound wave to the peak of the next. Electromagnetic wavelengths vary from the short blips of cosmic rays to the long pulses of radio transmission

Laser Projectors

The emitting laser light retains a single tight beam over distance, consumes less power, increases brightness, and delivers wider color gamut, more precise color saturation, immediate On/Off time, and longer source life.

HDCP (High bandwidth Digital Content Protection)

The encryption protocol applied at the digital interface between video sources and displays. Each HDCP-compliant device has a unique set of encryption keys to prevent unauthorized copying of protected content.

HD-SDI

The high definition version of SDI for carrying component, 720p and 1080i video over one coaxial cable. HD-SDI is used for video connections at 1.5 Gbps, supporting HD video, multi-channel audio, closed caption data, test signals, metadata, and error handling.

Rarefraction

The low sound region.

American National Standards Institute - ANSI

The main organization responsible for coordinating and publishing computer and information technology standards in the United States.

Frequency

The rate of repetition of a regular event. Sound wave vibrations are carried out as a repeating pattern, where one such repetition is one wave cycle. The frequency of a vibration is expressed in Hertz (Hz) where 1 Hz = 1 vibration, or 1 cycle per second.

RS-232

The recommended standard (RS) upon which all serial communication takes place on a PC.

Headroom

The safety zone allowing audio peaks to exceed the nominal level before clipping will occur.

Diffusion

The scattering of sound after reflecting off an irregular surface

Acoustics

The science or study of sound, how it's created, its ability to travel within a space, and the way it's managed.

SD-SDI

The serial transmission for component, 480i video over a single standard RG59 or RG6 coaxial cable. SD-SDI was primarily utilized on professional broadcast and video production equipment for bit rates up to 270 Mbps.

Phase

The time-based difference of wave forms, either acoustical or electrical

Resonance

The vibration of an object or space at a certain frequency

TMDS

Transition Minimized Differential Signaling

AV Signal Distribution

Transports audio and video signals from a source device to the destination. Determining the best method can be challenging when designing the AV system.

Pitch

a tone's experienced highness or lowness; depends on frequency

Waveform Audio File Format - WAV

Uncompressed audio file format for storing an audio bit stream on PC, Windows, Mac and Linux systems.

The Speed of Sound

Under normal atmospheric conditions, the speed of sound is 1128 feet (343 meters) per second.

Peaking

Used to compensate for the lack of analog bandwidth response in displays, monitors, and projectors, and also the frequency roll-off caused by long cable runs. The higher the frequency and longer the cable length, the more peaking may be required.

Default Gateway

Used to connect two independent networks together. The gateway allows the devices from one network with specified IP settings to connect with devices of another network with different IP settings.

Interlaced Scanning

Used to minimize the perception of flicker as the screen updated. Images were drawn in two alternate fields as odd and even numbered lines. The first pass displays the first and all subsequent odd numbered lines. The second pass displays the second line followed by al l even numbered lines.

Subnets

User routers to determine access and control across an entire network. Partitioning of a network is useful for security and performance, improving bandwidth, and easing network administration.

IPv6

Uses 128-bit Hexadecimal values (0-FFFF) with approximately 340 undecillion addresses.

IPv4

Uses 32-bit decimal-based values (0-255) are expressed as dot addresses, and provides 4.3 billion combinations.

Desktop Microphone

Usually optimized for speech applications and comes with a stand that securely lets the user position the mic on the surface.

Star Topology

Utilizes a central node that connects to every device on the network, acting as a multiport repeater in a LAN. It receives signals from the source device, then retransmits it to the destination.

Digital Signals

Waveforms are evaluated for leading and trailing edges. As the signal level falls below normal operating thresholds, this is referred to as the "digital cliff". Digital devices support input equalization, signal buffering, and output reclocking to maintain signal data path integrity and performance.

Extenders

Work as transmitter and receiver pairs to facilitate digital signal transmission over long distances via shielded or unshielded twisted pair, or fiber optic cable. In some cases, control signals and remote power can be included.

Noise Floor

noise inherent in the operation of an audio system when no signal is present.

Transmission Control Protocol (TCP)

provides reliable, ordered, and error-checked delivery of a stream of packets on the internet. TCP is tightly linked with IP and usually seen as TCP/IP in writing.

Types of Network Attacks

· Eavesdropping - Gaining access to data paths in the network to "listen in" or read traffic, often referred to as sniffing or snooping. · Wiretapping - Monitoring of network server lines and intruding by listening to conversations or recoding in an illegal way. · Port Scanning - Sends several requests to a range of ports on a targeted host in order to find out what ports are active and open. · Idle Scan - Sends spoofed packets (impersonating a computer) to another computer to find out what services are available. · Virus - A program activated by attaching copies of itself to executable objects, files, or programs. · Malware - Malicious programs and techniques that pose a threat to your system as worms, trojans, adware, spyware, etc. · Denial of Service - Prevents normal access to a website, server, or network for its intended users. · Man in the Middle - When someone between you and the person with whom you are communicating is actively monitoring, capturing, and controlling your communication transparently. · DNS Spoofing - Tricking the DNS server to redirect traffic from one website to another by forging DNS entries. · VLAN Hopping - An attacking host on a VLAN to gain access to traffic on other VLANs that would normally not be accessible. · Phishing - Posing as a legitimate institution to lure individuals into providing sensitive data, personal information, banking and credit card details, and passwords.

Data Rates

· Ethernet: 10Base-T - 10 Mbps · Fast Ethernet: 100Base-T - 100 Mbps · Gigabit Ethernet: 1000Base-T - 1 Gbps (1,000 Mbps) · 10G Ethernet: 10GBase-T - 10 Gbps (10,000 Mbps)

Designing a Network

· Needs Analysis to define the purpose of the network, target customer and readiness dates. · Physical and Logical Design to determine the topology, switch backplane, device location, and cabling. · Security implementation that includes risk analysis, mitigation plans, confidentiality, integrity, availability, system backup and restore measures. · Quality identifying fault tolerance, Quality of Service and differentiated services categories. · Maintenance dependent on availability of spare equipment, redundancy, switch-fill capacities, and expansion. Also keeping the switch and firewall software up to date. · Implementation of timelines, schedules, training, and documentation. · Expansion planning of infrastructure, ports, etc.

Fiber Optic Cabling

· Singlemode - high speed light path retains signal fidelity over longer distances at a higher bandwidth compared to multimode. · ​​​​​​​Multimode - internal light reflections are dispersed at low speed over short runs.

Cable Shielding

· Unshielded Twisted Pair - UTP (no overall shield, no wire pair shield) · Foil/Unshielded Twisted Pair - F/UTP (overall foil, unshielded wire pairs) · Unshielded/Foil Twisted Pair - U/FTP (no overall shield, foil wire pairs) · Foil/Foil Twisted Pair - F/FTP (overall foil, foil wire pairs) · Braid & Foil/Unshielded Twisted Pair - SF/UTP (overall braid & foil, unshielded wire pairs) · Braid/Foil Twisted Pair - S/FTP (overall braid, shielded wire pairs)