CETel Tech Glossar

BIZ CETel

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AES

• Advanced Encryption Standard is an encryption standard comprised of three blocks of ciphers AES‐128, AES‐192, and AES‐256

ACM

• Adaptive Coding and Modulation uses an algorithm to dynamically change the coding and modulation scheme based on atmospheric conditions and network configurations

APSK

• Amplitude and Phase Shift Key is a modulation scheme that changes the amplitude and phase of the carrier wave

Analog transmission

• Transmission of information using a continuous signal that varies based on amplitude, phase, or other proportion

Antenna

• VSAT Main Equipment that typically transmits and receives electromagnetic waves, usually referred to as the satellite dish

Azimuth - Altitude/Elevation

• Azimuth = horizontaler Winkel vom Referenzpunkt (Nord) zum POP
  • Reference plane = Horizont
  • Nord = 0° & Süd = 180°; positive Winkelangaben gelten clockwise=rechtsrum und negative Winkelangaben gelten linksrum=counter clockwise
• Altitude oder Elevation = vertikale Winkel auf reference plane (Horizont)
• Elevation Angle Calculator
• Elevation Angle Calculator

Bandbreite vs. Datenrate

• Bandbreite ist der Frequenzbereich des Übertragungsmedium gemessen in Hz, aslo die Differenz zwischen größter und kleinster Frequenz, mit der ein Signal über ein bestimmtes Medium übertragen werden kann - Je höher die Bandbreite, umso mehr Daten können theoretisch übertragen werden
• Datenrate oder Bitrate gemessen in Bit/s gibt an, wie viele Informationen je Zeiteinheit über ein spezielles Medium übertragen werden können - kleinste Dateneinheit ist ein Bit

Bandbreite	Medium	Datenrate
gering	Kupferkabel	1200-1400 Bit/s
	verdrillte Kupferkabel / Twisted Pair
bis	Koaxialkabel	bis
	Funkstrecke
hoch	Glasfaserkabel	10 GBit/s

• Shannon-Hartley-Theorem
  • C=Datenrate, B=Bandbreite, S=Signalleistung, N=Rauschleistung
  • C = B x Log2(1+S/N)

BUC

• VSAT Main Equipment
• Block Up Converter
• Used for uplink satellite transmission that converts a band from a lower (L-band) frequency to a higher frequency (C-band, Ka-band, Ku-band)

Bandwidth

• A range of frequencies within a spectrum, expressed in Hertz
• Can also be the data transfer rate or throughput, expressed in bits per second

BGP

• Border Gateway Protocol is a core routing protocol of the Internet

Bit Rate

• Speed of transmission, measured in bits per second (bps)

BPSK

• Binary Phase Key Shifting is a modulation scheme that uses two phases separated by 180 degrees

Broadcasting

• Sending a single transmission to multiple sites that are capable of receiving the signal

CDMA

• Code Division Multiple Access is a radio communication technology that uses channel access method

C‐band

• Frequency band with uplink 5.925‐6.425 GHz, downlink 3.7‐4.2 GHz. The C band is primarily used for voice and data communications as well as backhauling
• Differ between standard C-band and extended C-band

Cellular Backhaul

• Transmission of cellular voice and data signals, typically from a base station to a remote site

Carrier to Noise Ratio (C/N)

• The ratio of the received carrier power and the noise power in a given bandwidth, expressed in dB. This

figure is directly related to G/T and S/N. Typically in a signal, the higher the C/N, the better the quality

Circular Polarization

• Refers to a method of transmitting signals from a satellite
• On some satellites, both right‐hand rotating and left‐hand rotating signals can be transmitted simultaneously on the same frequency; thereby doubling the capacity of the satellite to carry communications channels

Coverage

• Footprint or the area on the earth's surface that is covered by a satellite's transmission beam

dBW

• The ratio of the power to one Watt expressed in decibels
• Typically the E.I.R.P of satellite beams are measured in dBW

D‐TDMA

• Deterministic Time Division Multiple Access – iDirect’s patented access technology that provides simultaneous access to shared upstream channels using dynamically assigned time slots

Delay

• The time it takes for a signal to go from the sending station through the satellite to the receiving station
• This transmission delay for a single hop satellite connection is very close to 240 ms

Double Hop

• Transmission of information from one terminal to another terminal in two stages, first from a remote site VSAT up to the satellite to the network hub or from the network hub up to the satellite then to another remote site

Downlink

• Transmission of a signal from the satellite to the earth
• In a network it is typically referred to the link between a network hub over the satellite to a remote site

DVB‐S2

• Digital Video Broadcasting – Satellite – Second Generation is the enhanced version of the DVB‐S satellite broadband transmission standard and has forward error correction and modulation specifications

Earth station

• Ground equipment that transmits and receives electromagnetic waves, also referred to as an antenna

EIRP

• Effective Isotropic Radiated Power. This term describes the strength of the satellite signal in dBW and is a result of the transponder output power and the gain of the satellite transmit antenna

EMEA

• World Region including Europe, Middle East and Africa

Evolution

• iDirect’s next‐generation product line of routers, line cards, and iDX software, all built on the DVB‐S2 standard with Adaptive Coding and Modulation (ACM)

FDMA

• Frequency Division Multiple Access. It is a channel access method that allocates each application or user a different frequency band

Fehlerkorrekturen

• BER Bit Error Rate
• FEC = Forward Error Correction
  • Normally in the range of 1/2 and 7/8
  • TDR = transmission data rate is always significantly more than the CIR = customer information rate

FEC

• Forward Error Correction. It is the system for error control that has the sender include redundant data so errors can be detected and corrected at the receiver

Financials

• OPEX + CAPEX = TOTEX
• Turnover = Umsatz
• EBITDA marge = Earnings Before Interest Taxes, Depreciation, Amortisation

FIPS 140‐2

• Federal Information Processing Standard Publication 140‐2 is a U.S. government computer security standard that accredits cryptography modules

Footprint

• The area on the earth's surface that is covered by a satellite's transmission beam

Fragestellungen

Equipment vor Ort - VSAT Main Equipment

• Welcher Ort, welche Lokation, Koordinaten, Name
• Modem Type
• Modem Software-Release
• neuer oder existierender Service, bei letzterem auch:
  • inbound modulation code
  • outbound modulation code
• BUC size
• Antenna/Dish size
• LNB type

Satellit

• Bevorzugter Satellit
• Bevorzugtes Frequenzband

Service

• Download in MBPS
• Upload in MBPS
• Shared oder dedicated service
• Welche Anwendung steht dahinter

Frequenzband

• C-Band benötigt etwas mehr als 40db um mit Standard-Equipment zu recht zu kommen
  • Braucht größere Antennen als Ku-Band
• Ku-Band benötigt um die 40db um mit Standard-Equipment zu recht zu kommen, ist aber in feuchten und nierderschlagsreichen Gegenden weniger geeignet
  • FSS-Standard Ku:
  • FSS-Extended Ku:
  • FSS-Low Ku (komplizierter zu realisieren): 12750-13000
  • BSS-DBS standard: 17300-18000
  • BSS-DBS extended: 18001-18300

Gain

• A measure of amplification expressed in dB

GEO

• Geostationary Earth Orbit satellites orbit at 35,786 km (22,282 mi) above the equator in the same direction and speed as the earth rotates on its axis, making them appear as fixed in the sky

Global Fiber Routes

• FLAG = Fiber-Optic Link Around the Globe (FLAG) is a 28,000-kilometer-long submarine communications cable containing optical fiber that connects the United Kingdom, Japan, and many places in between
• WACS = West African Cable System = Main Fiber Submarine Cable of West Africa
• EASSY = Eastern Africa Submarine Cable System = Main Fiber Submarine Cable East Africa
• Fiber Afrika

GSM

• Global System for Mobile communications is a standard for digital wireless communications to mobile phones

GQoS

• Group Quality of Service is iDirect’s bandwidth allocation and prioritization algorithm that allows for countless possibilities of quality of service levels, bandwidth management and traffic prioritization

G/T

• A figure of merit of an antenna and low noise amplifier combination expressed in dB "G" is the gain of the system and "T" is the noise temperature
• The higher the G/T, the better the system

Guard Band

• Transmission carriers are separated on a transponder by spacing them several kilohertz apart
• This unused space serves to prevent the adjacent transmission carriers from interfering with each other

HNO

• Host Network Operator is a network operator who leases out hub space to smaller service providers

HTTP

• Hyper Text Transfer Protocol is an application level protocol used to request and transfer objects across the web

Hub

• Satellite network equipment that controls the satellite bandwidth allocation, often located at a teleport
• It usually consists of a chassis, a PP (protocol processor) and NMS (network management system) and other equipment connected to terrestrial networks

IDU

• Indoor Unit is network equipment typically located inside a building that consists of a modem and router (or hub if it inside a teleport) connected to the corporate LAN or terrestrial infrastructure

IP

• Internet Protocol is a protocol used for data communication across a packet switched network
• Typically used with TCP, a higher level protocol

ISO

• International Organization for Standardization is a standard setting body composed of multiple national standards organizations

ISP

• Internet Service Provider is a company that offers Internet access to customers

ITU

• International Telecommunication Union is a United Nations organization helping governments and private organizations coordinate global telecommunications usage

Inbound

• Transmission of a signal to the satellite. In a network it is typically referred to as the transmission from the remote router to a satellite to a hub

Inroute

• See Inbound

iNFINITI

• iDirect’s product line of routers and line cards, built on iDirect’s proprietary implementation of the TDM protocol

Ka Band

• Frequency band with uplink 26.5‐40GHz; downlink 18‐20 GHZ, this band is primarily used for two‐way consumer broadband

Kbps

• Kilobits per second - Refers to transmission speed of 1,024 bits per second

Ku-band

• Frequency band with uplink 14 GHz; downlink 10.9‐12.75 GHz, with more powerful transmission from the satellite more susceptible to rain fade than C‐Band
• Differ between standard Ku-band and extended Ku-band

LAN

• Local Area Network is a computer network that covers a small physical area

LOS - Line Of Sight

• The path between two antennas is referred to as the Line of Sight (LOS) - There are three main categories of Line of Sight:

1. Clear Line of Sight (cLOS) or even Line of Sight (LOS) where no obstacles reside between the two antennas
2. Near Line of Sight (nLOS) which includes partial obstructions such as tree tops between the two antennas
3. Non Line of Sight (NLOS) where full obstructions exist between the two antennas

• By determining the specific line of sight conditions in the WiFi network area you can then determine the correct type of wireless system to install
• Fresnel Zone
  • Is an electromagnetic phenomenon, where light waves or radio signals get diffracted or bent from solid objects near their path
  • The radio waves reflecting off the objects may arrive out of phase with the signals that traveled directly to the receiving antenna thus reducing the power of the received signal.

Low Noise Amplifier (LNA)

• This is the preamplifier between the antenna and the earth station receiver
• For maximum effectiveness, it must be located as near the antenna as possible, and is usually attached directly to the

antenna receive port

Low Noise Block Downconverter (LNB)

• VSAT Main Equipment
• A combination Low Noise Amplifier and downconverter built into one device attached to the feed
• It is used for the downlink satellite transmission by converting a band from a higher frequency to a lower frequency

L‐Band

• Frequency band from 1 to 2 GHz, this band is the result of the down‐conversion of the received downlink satellite signal from the LNB

LDPC

• Low Density Parity Check is a forward error correction code that is currently the most efficient scheme, used with DVB‐S2

LEO

• Low Earth Orbit satellites orbit from 160‐2000km above the earth and take approximately 1.5 hrs for a full orbit and only cover a portion of the earth’s surface

MEO

• MEO satellites are located above LEO and below GEO satellites and typically travel in an elliptical orbit over the North and South Pole or in an equatorial orbit

Mesh network

• Topology whereby a remote VSAT location communicates with another remote location without routing through the hub

MF‐TDMA

• Multiple‐Frequency Time Division Multiple‐Access is a broadband access method where different data streams are put into different slots that are separated by both frequency and time

Modem

• VSAT Main Equipment
• A piece of network equipment containing a modulator and demodulator for receiving or transmitting satellite signals

Modulation

• The encoding of a carrier wave by amplitude or frequency or phase
• ACM = Adaptive Code Modulation - verschlechtern sich die Übertragungsbedingungen
  • wird automatisch zunächst die FEC erhöht (7/8 runter aus 1/2) - wenn das nicht ausreicht
  • wird der Modulationsindex herabgesetzt, z.B. von 8PSK auf QPSK
• Relation of Data Rate to Kilohertz

Winkelmodulation

Phasenmodulation / Phasenumtastung / Phase Shift Keying = PSK

• Die Phase einer Sinus-Schwingung (Träger) wird durch Phasenverschiebung (0° / 180°) moduliert
• Bei mehrstufigen Phasenmodulationen repräsentiert ein Symbol eine Folge mehrerer Bits
  • 2PSK = 1 bit pro Symbol = 2^1 = 2
  • 4PSK = 2 bit pro Symbol = 2^2 = 4 = QPSK
  • 8PSK = 3 bit pro Symbol = 2^3 = 4
  • 16APSK = 4 bit pro Symbol = 2^4 = 16 = Asymmetric PSK
  • 32APSK = 5 bit pro Symbol = 2^5 = 32 = Asymmetric PSK

Quadratamplitudenmodulation / Quadrature Amplitude Modulation = QAM

• Kombination aus Amplitudenmodulation und Phasenmodulation
• Der Träger wird mit Kreisfrequenz zweifach mit 90° Phasenverschiebung verwendet
• Dabei werden mittels "multiplikativer Mischung" zwei unabhängige Basisbandsignale aufmodelliert
  • 4QAM = 4 Punkte im 2x2 Raster (Kreis) = DVB-S
  • 8QAM = 8 Punkte (9 Punkte abzüglich Mittelpunkt) im 3x3 Raster (Kreis)
  • 16QAM = 16 Punkte im 4x4 Raster (Kreis) DVB-T, ITU-R Norm V.29
  • 32QAM = 32 Punkte (abzüglich 4 Eckpunkten) im 6x6 Raster (Kreis)
  • 64QAM = 64 Symbole im 8x8 Raster (Kreis) DVB-C und DVB-T etwa 10GB/s
  • 256QAM
  • 1024QAM
  • 4096QAM

Modulator

• A device which modulates a carrier

Multicast

• Multicast is a subset of broadcast whereby the signal can be sent to many sites within a defined group, but not necessarily to all sites in that group

Multiplexing

• Sending multiple signals or streams of information on a carrier simultaneously transmitting on a single signal

NMS

• Network Management System is the hardware and software that monitors and controls a satellite network

NOC

• Network Operations Center is a centralized location where control over operation of a network is managed and monitored

ODU

• An Outdoor Unit is the equipment located outside of a building close to the satellite dish or antenna and typically includes, a low noise block converter (LNB), and a block‐up‐converter (BUC)

Outbound

• Transmission of a signal from the satellite to an antenna
• In a network it is typically referred to as the transmission from the hub to a satellite to a remote router

PBX

• A Private Branch Exchange is a telephone exchange that connects a private enterprise or organization to the public switched telephone network (Telefonanlage)

PCMA

• The Paired Carrier Multiple Access (PCMA) Hub Canceller is a satellite signal canceller that maximizes the capacity of satellite networks by using ViaSat’s patented PCMA technology to reduce satellite bandwidth as much as 50 percent

Polarization

• A technique used by satellite operators to reuse the satellite transponder frequencies when transmitting

these signals to Earth

• Two methods are possible: linear and circular
• To successfully receive and decode these signals on earth, the antenna must be outfitted with a properly polarized linear or circular

feedhorn to select the signals as desired

PSK

• Phase Shift Key is a digital modulation scheme that changes the phase of the carrier wave

PSTN

• Public Switched Telephone Network is an international network for public circuit‐switched voice telephony

Quality of Services / QoS

• Quality of Service provides priority and guarantees a certain level of network response time and other performance factors for each application and user
• QoS Aspekte

1. Latenzzeit (Verzögerung im End2End)
2. Jitter (Abweichung Latenzzeit vom Mittelwert)
3. Paketverlustrate
4. Durchsatz

• Anwendungsaspekte
  • Telnet ist v.a. abhängig von 1
  • Datentransfer ist v.a. von 4 weniger von 1 oder 3 abhängig
  • VoIP als realtime application ist v.a. von 1, 2 und 3 abhängig
  • Video wird dagegen von 4 als Abhängigkeit dominiert und 1,2, und 3 sind bei realtime video eingebunden

QPSK

• Quadrature Phase Key Shifting is a modulation scheme that uses four phases

Rain Fade

• Decrease of satellite signal strength due to rainfall
• This occurs typically at Ku Band frequencies due to its increased sensitivity to noise temperature

RF

• Radio Frequency is the electromagnetic frequencies for wireless transmission that is above the audio range and below infrared light

RF Stecker

• SMA Connector 50 Ohm (kleiner, als typischer Haussatellitenkabelstecker)
• F-Type Connector 75 Ohm (typischer Haussatellitenkabelstecker)
• N-Type connector 50 Ohm (größer, als typischer Haussatellitenkabelstecker)
• BNC Connector 50 or 75 Ohm

RIP

• Routing Information Protocol is a dynamic routing protocol used in local area and wide area networks

Roll-Off Factor

• The roll-off factor of a digital filter defines how much more bandwidth the filter occupies than that of an ideal "brick-wall" filter, whose bandwidth is the theoretical minimum Nyquist bandwidth
• The Nyquist bandwidth is simply the symbol rate expressed in Hz: Nyquist Bandwidth (Hz) = Symbol Rate (Sym/s)

Router

• A device connected to the modem and the antenna on one side and the computers and other LAN devices on the other side
• It forwards IP packets based on network layer information and enables applications such as VoIP, Video and data

RTTM

• Real Time Traffic Management is an iDirect feature set that is designed to enable high‐quality transmission of voice applications that are less tolerant to delay or jitter that can occur on satellite links

Satellite

• Communications satellites orbit the earth and transmit and receive radio signals from earth stations

SCADA

• Supervisory Control and Data Acquisition is the system that monitors and controls industrial or facility based remote devices

Single‐Channel‐Per‐Carrier (SCPC)

• A satellite access method that dedicates one channel to each remote site, sometime used for very high capacity links
• See also TDMA

Signal to Noise Ratio (S/N)

• The ratio of the signal power and noise power
• The higher the number the better the quality

Single hop

• Transmission of information from one remote site to another antenna
• Typically it describes the path between two remote stations in a mesh network
• Single hop occurs when transmission is passed from one remote directly to another mote without having to go to the hub (double hop)

SNG - Satellite News Gathering

• Satellite news gathering typically done from a transportable unit (truck or mobile entity) to transmit video and voice feeds back to the studios

Spot Beam

• A spot beam is a satellite signal that covers a concentrated geographic area so only antennas in that area will receive the signal

Spread Spectrum

• Eliminates adjacent satellite interference by spreading the signal over the available bandwidth to enable extremely small antennas or phased array antennas in mobile operations

Star network

• Topology whereby a remote VSAT location communicates with another remote location by routing through the hub

TCP

• Transmission Control Protocol is a core Internet protocol that is a higher level protocol often combined with IP

TDMA

• Time Division Multiple Access is channel access method that allows applications or users to share the same frequency by dividing the full bandwidth into specific timeslots

Transponder

• Receives outbound signal at the satellite and amplifies the signal before retransmitting it to an earth station

Transponderkenngrößen

Bandbreite

• The 3dB Satellite Bandwidth is the bandwidth of the transponder
  • Typically it is 36 MHz, 54 MHz or 72 MHz and represents the physical bandwidth of one receiver-amplifier-transmitter chain on the satellite
  • It may contain one or many carriers
  • It is important in the calculation because the derived carrier (when you supply the DVB parameters) must have a bandwidth of less than the satellite physical bandwidth
• The Occupied Bandwidth
  • It represents the bandwidth of the receiver that is needed to receive and demodulate the carrier successfully
  • Occupied Bandwidth = (1 + Roll-off factor) * Symbol Rate
  • Typically, as a rule of thumb: Occupied Bandwidth = (1 + 0.2) * Symbol Rate
• Allocated Bandwidth
  • This is the actual bandwidth on the satellite that is reserved for the transmission of the carrier
  • It is wider than the Occupied Bandwidth in order to avoid interference between the carriers (from the "tails" of the spectrum, which will overlap with the adjacent carriers)
  • Typically, as a rule of thumb: Allocated Bandwidth = (1 + 0.4) * Symbol Rate
• Suggestion:
  • download and install the free trial of the Satmaster Pro link budget software
  • this will let you experiment with different values of these bandwidths and see the impact on the transponder fill-factor

Polarisation

• Linear
  • Horizontal
  • Vertical
• Circular
  • LHCP = left handed circular polarisation = linksdrehend
  • RHCP = right handed circular polarisation = rechtsdrehend

Frequenzbereich

• Uplink
• Downlink

Ausleuchtzone

• Global Beam
• Spot Beam

TRANSEC

• Transmission Security secures VSAT transmissions with encryption to prevent from interception and exploitation

Turbo Codes

• 2D16-state: 10-20% erhöhter Durchsatz zu Standard-Turbo-Codes ohne dass Performance beeinträchtigt wird

Uplink

• Transmission of a signal from the remote router to a satellite to a hub

Verschlüsselung

• IPsec geht wegen Paketverschlüsselung nicht
• AES funktioniert wegen Prozessverschlüsselung

VLAN

• Virtual LAN is a group of hosts that simulates a LAN although they are not located locally on the same network switch

VNO

• Virtual Network Operators lease hub space from HNOs while keeping complete control of their network and their remotes
• iDirect offers this capability by assigning each VNO operator its own line cards and NMS servers and protocol processors
• The VNO commissions, controls and operates its remote sites in the proprietary network as if it owns a physical hub

VSAT

• Very Small Aperture Terminal is an antenna that is typically less than 3 meters in diameter

WAN

• Wide Area Network is a computer network that covers a broad area that connects multiple remote locations.

WGS

• Wideband Global Satcom is a satellite communication system used by the U.S. Department of Defense

X‐Band

• Frequency band with uplink 7.9‐ 8.4 GHz, downlink 7.25 – 7.75 GHz, this band is primarily used for military communications and Wideband Global Satcom (WGS) systems

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