1,A,B,C,D,E,F,G,H,I,J,K,L,M,N,O,P,Q,R,S,T,U,V,W

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1

100BaseT A generic name for 100 Mb/s twisted pair CSMA/CD proposals before the IEEE 802.3. Specific proposals include 100BaseTx and 100BaseT4.

100BaseTX The IEEE 802.3u specification for Cast Ethernet over Category 5 (CAT5).

100BaseFX 100 Mbps Ethernet implementation over fiber.

10BaseT A 10 Mbps Ethernet specification defined by the IEEE 802.3 committee that utilizes category 3 or category 5 twisted pair wiring. The maximum segment length is 100 meters and is installed in star topology to a central hub.

B
 

Backhaul ­In a WAN network, communications between a WAN port on a LAN and either a subscriber port on a service provider’s network or another WAN port on a second LAN. Often the backhaul links the user’s facilities to the backbone.

Bandwidth ­The information carrying capacity of a communications channel.

BER ­Bit Error Rate. Ideally no errors will be received occur a connection; in practice, due to noise, other signals, etc. errors will occasionally occur, even on a fiber link. A bit error test checks the physical link to verify that the number of errors received over a test period is within design limits.

 
BPSK ­Binary Phase Shift Keying uses a single carrier with the phase shifts of 180° to carry the signal.
 

C
 

Capacity ­The average amount of traffic a circuit or port can handle. Capacity may be measured in terms of the number of VF channels or the aggregate data rate of the main signal.

CIR ­Committed Information Rate. The average rate of information transfer a subscriber has stipulated for a Frame Relay permanent virtual circuit. For the BWS Release 2 product this will apply to the aggregate total of the virtual connections established for a single user across the air interface from the AP to the CPE’s.

COGS ­Cost Of Goods Sold. Includes cost of materials, manufacturing & overhead. Does not include profit and customer shipping.

CPE ­Customer Premises Equipment. Communication equipment residing on the end user’s side of the network interface boundary. Also used to describe the BWS Remote Station (IDU and ODU.)

CRC ­Cyclic Redundancy Check. An error detection calculation / error detection code used in data transmission.

CT ­Craft Terminal. A personal computer with appropriate application software used by maintenance personnel to conduct OAM&P functions.

D
 

DS­1 ­Digital Signal 1, a serial digital signal transmission format in which 24 duplex voice circuits are time division multiplexed into one 1.544 Mbps T1 digital circuit. May also be expressed as T1.

DSX­1 ­Digital Signal Interface 1, the standard levels, mask, etc. that specify the format of the signal at an interface point.

DS­3 ­Digital Signal 3, 44.7 Mbps or equivalent to 672 duplex voice circuits or 28 DS­1 signals.

Duplex ­A circuit or device that permits transmission in two directions at once (receiving and transmitting).
 

E
 

E1 ­Specialized circuit developed in Europe for transmission of digital signals over the telephone network at 2.048 Mbps or equivalent to 30 duplex voice circuits plus two data channels. Also, E2 at 8 Mbps, E3 at 34 Mbps, and E4 at 140 Mbps.

EIRP ­Effective Isotropic Radiated Power. Effective Isotropic Radiated Power (EIRP) is a figure of merit for the net radiated power in a given direction. It is equal to the product of the power supplied to a transmitting antenna and the antenna gain in a given direction relative to an isotropic radiator, expressed in Watts.

EMC ­Electromagnetic Compatibility. International standards for emissions of, susceptibility to, and conduction of electromagnetic signals.

Ethernet ­A baseband LAN specification to network computers at 10 Mbps using CSMA/CD to run over coaxial cable. Referenced by IEEE standard 802.3.

 
ETSI ­European Telecommunications Standards Institute

Extranet ­A private network that uses Internet software and standards with limited external access, typically for an organization’s suppliers and customers.
  

F
 

Fading ­an effect caused during the transmission of radio signals due to the non­uniform nature of the atmosphere. Signals may fade up or down occasionally over time and sufficient margin is required to maintain a reliable connection.

FCC ­Federal Communications Commission. The U.S. federal regulatory agency responsible for the regulation of interstate and international communications by radio, television, wire, satellite and cable.

FDD ­Frequency Division Duplexing. A design in which different frequencies are used for the Tx and Rx channels. Each Access Point uses separate frequency channels to transmit and receive.

FEC ­Forward Error Correction. A communications technique used to correct bad data on the receiving end. Before transmission, the data is processed through an algorithm that adds extra bits for error correction. If the transmitted message is received in error, the correction bits are used to repair it.

Frequency ­The number of cycles per second at which a current alternates, usually expressed in Hertz (Hz).

FSO – Free Space Optics.
 

G
 

GHz ­Gigahertz. The microwave frequency range, a signal frequency equivalent to one billion cycles per second. Gigabit ­Ten million bits of information. Gigabits per second (Gbps) is the transmission of ten million bits of information per second, or 1,000 Mbps; also Gigabit Ethernet, 1000 BaseT.

H
 

Hertz ­Unit of frequency equal to one cycle per second.

Hop ­Refers to a single point­to­point radio link, generally including two radio terminals and antenna systems.
 

I
 

ICMP ­Internet Control Message Protocol. In the Internet, a protocol that provides a means for communicating computers (both routers and hosts) to exchange error and informational messages in an IP network.

IEC ­The International Electrotechnical Commission is the international standards and conformity assessment body for all fields of electrotechnology.

IDU ­Indoor Unit. That portion of the BWS system at either the AP or CPE that is located inside of the building. The IDU is connected to the ODU via an IF interface.

IF ­Intermediate Frequency.

IP ­Internet Protocol. An OSI model Layer 3(network) format with addressing information and some control information for routing packet traffic on wide networks, such as the Internet. Documented in RFC 791.

ISM ­Industrial Scientific Medical Band. The category of user devices originally permitted to operate as radio transmitters with no user license under Part 15 in the USA in the 902­928 MHz, 2.4­2.4835 GHz, and 5.725­5.85 GHz bands.

ISP ­Internet service provider; a company selling Internet access and gateway services to individuals or organizations by providing an interface to the Internet backbone.
  

J
 

Joint Application Design (JAD) ­A parallel process simultaneously defining requirements in the eyes of the customer, users, sales people, marketing staff, project managers, analysts, and engineers. You can use the members of this team to define requirements.

K
 

Kbps ­Kilobits Per Second, a data rate equal to 1.000 bits per second.

L
 

LAN ­A privately owned and administered network for data communications. “Local Area Network”.

Last Mile ­The access portion of a network that extends the backbone to the end­user or customer.

LE­LAN ­license exempt LAN; unlicensed wireless regulation established by Industry Canada (IC) that matches the UNII band in the USA.

Local Area Network (LAN) ­A series of connected workstations and computers that are linked in a limited geographical area (e.g. office, building, and/or campus). LANs are usually low­cost, high­bandwidth networks which connect many nodes using Ethernet.

M
 

MAC ­Media Access Control. A sub layer of the Open Systems Interconnect Data Link Layer protocol, which gives rules for resolving contention from multiple transmitters which transmit on a shared transmission medium.

MBR ­Maximum Bit Rate. The absolute maximum bit rate allocated to a subscriber by a SLA. The system will allow the subscriber to burst up to the MBR.

Megabit ­One million bits of information. Megabits per second (Mbps) is the transmission of one million bits of information per second.

MEGACO ­Media Gateway Control. Also know as H.248. A joint IETF/ITU standard to replace MGCP as the communications protocol between Media Gateway Controllers and Media Gateways.

MGCP ­Media Gateway Control Protocol. Defines the communications procedures for a Media Gateway Controller to provide instructions to and gather information from Media Gateways. Also defines an Application Programming Interface for creating services that use the protocol.

MIB ­Management Information Base. A network management data structure that maintains performance statistics and settings on a specific network component, such as a router, switch or multiplexer.
 

Microwave ­Electromagnetic waves in the radio frequency spectrum generally above 900 MHz and below 20 GHz; sometimes millimeter bands at 23 and 38 GHz are included in the category.

MIR ­Maximum Information Rate. The MIR is specified at set­up time and is used by the traffic policing mechanism to prevent users from sending excess traffic to the network.

MTBF ­Mean Time Between Failures. An indicator of expected system reliability calculated on a statistical basis from the known failure rates of various components of the system. Usually expressed in hours.

MTBO ­Mean Time Before Outage. An indicator of expected system availability from known failure rates of the system.
 

MTTR ­Mean Time To Repair. The total corrective maintenance time divided by the total number of corrective maintenance actions during a given period of time.

Multipath ­wireless reception of multiple signals over one or more paths; in a normal line­of­sight fixed wireless link, the direct path dominates the received signal. During fading conditions or when the direct line­of­sight path is obstructed, one of more signals from objects causing reflections may be received. Reflected signals may cause constructive or destructive interference and the wireless link must be designed to operate reliably in multipath situations.

Multiplexing ­Generally, a method of combining more than one signal or channel onto a single circuit or signal.
 

N
 

NEBS ­Network Equipment Building System. A series of standards issued by Telcordia Technologies (formerly Bellcore) having to do with the conformance of telecommunications equipment to mounting, powering, environmental conditions, etc.

Network Layer ­Layer 3 of the OSI model, at which routing occurs using the network address.

NLOS ­Non Line of Sight. No line can be drawn between two transmitting devices. Total visual blockage has occurred  between the transmitting and receiving devices. Extremely large amounts of reflection, refraction and diffraction can occur on a direct ray between the transmitter and receiver.

NMS ­Network Management System. The system that is responsible for managing a network (or a portion of the network), via a network management protocol such as SNMP.

Node ­A termination point for two or more communications links. The node can serve as the control location for forwarding or switching data among the elements of a network.

NrLOS ­Near Line of Sight. NrLOS may be considered a visually obstructed line of sight between two transmitting devices but a straight line can still be drawn. Reflection, refraction and/or diffraction on a direct ray between the transmitter and receiver have occurred.

O
 

OAM&P ­Operations, Administration, Maintenance, & Provisioning. The broad categories of functions found in a communications network and/or the business processes found in network service provider companies.

OC­3 ­Optical Carrier 3. Approximately 155 Mbps; a signal in the SONET hierarchy designed for fiber optic transmission.

OC­12 – Optical Carrier 12. Approximately 622 Mbps; a signal in the SONET hierarchy designed for fiber optic transmission.

ODU ­Outdoor Unit. That portion of the BWS system at either the AP or AD that is located outside of the building. The ODU is connected to the IDU via an IF interface.

OFDM – Orthogonal Frequency Division Multiplexing. An FDM modulation technique for transmitting large amounts of digital data over a radio wave. OFDM works by splitting the radio signal into multiple smaller sub­signals that are then transmitted simultaneously at different frequencies to the receiver. OFDM reduces the amount of crosstalk in signal transmissions.

 
OSI Model – 7 layer standard developed under the ISO and used as a reference for multilayer protocol stacks for data communications.

P
 

Packet Switching ­Transmission technique for data to allow efficient sharing of network resources from multiple sources on the same channel. Messages are split into packets and reassembled at the receiving end of the link.

Part 15 ­The part of the FCC’s rules relating to unlicensed radio equipment.

Part 15.247 ­The part of the FCC’s rules relating to unlicensed spread spectrum transmitters in the ISM bands. Similar rules are available in many other countries.

Part 15.401 ­The part of the FCC’s rules relating to unlicensed UNII transmitters in the 5 GHz band.

Part 18 ­The part of the FCC’s rules relating to other unlicensed ISM equipment.

 
Part 21 ­The part of the FCC’s rules relating to common carrier microwave equipment.

Part 94 ­The part of the FCC’s rules relating to private operational fixed (OFS) microwave equipment.

Part 101 ­The part of the FCC’s rules consolidating the rules for Part 21 and Part 94 microwave equipment in the bands above 3 GHz.

PDN ­Public Data Network. A generic term for the collection of networks that provide public data services. Well­known examples are the Internet and X.25.

Point­to­Multipoint ­a radio link with a central or hub site and two or more remote sites connected in a star topology with shared bandwidth.

Point­to­Point ­A radio link established between two locations along a single line or path with dedicated bandwidth.
 

Q
 

QAM ­Quadrature Amplitude Modulation. A modulation technique that uses two carriers in quadrature (using sine and cosine carriers that are 90° apart), and each carrier is modulated in amplitude.

QoS ­Quality of Service. A broadly used term that refers to the performance attributes of an end­to­end connection. A QoS definition for data would address attributes such as error rates, lost packet rates, throughput, and delay.

QPSK ­Quadrature Phase Shift Keying uses the sum of two carriers (typically a sine and a cosine) whose phases are 90° apart from one another (hence, in quadrature) to carry the signal.
 

R
 

R&TTE ­R&TTE/RTTE Directive 1999/5/EC is the European radio and telecommunications regulation which affects manufacturers, suppliers and importers of radio equipment and telecommunications terminal equipment who wish to place such equipment on the market of the European Economic Area (EEA). The EEA includes the following countries: Austria, Belgium, Denmark, Finland, France, Germany, Greece, Iceland, Ireland, Italy, Liechtenstein, Luxembourg, Netherlands, Norway, Portugal, Spain, Sweden, United Kingdom.

RF ­Radio Frequency. Generally referring the carrier frequency of the radio.

RIP / RIP­II ­Routing Information Protocol. A protocol for exchanging network reach ability and routing information between routers in a router­based network.

RJ­11 ­A modular 4­wire jack and/or connector typically used with copper cable having two twisted pairs usually unshielded twisted pair Category 3 or Category 5. Used for telephony, 10Base­T and 100Base­Tx Ethernet LANs, and Token Ring LANs.

RJ­45 ­A modular 8­wire jack and/or connector for use with copper cable having four twisted pairs, typically unshielded twisted pair Category 3 or Category 5. Used for telephony, ISDN, 10Base­T and 100Base­T4 Ethernets, 100VG­AnyLAN, and Token Ring LANs.

Router ­A Layer 3 device that manages the connection between one or more networks based on network layer information. Routers find paths for packets to reach their destination host over complex networks with potential intermediate destinations.

RSS­210 ­The Industry Canada rule equivalent to FCC Part 15.247 for unlicensed spread spectrum transmitters.

RSSI ­Receive Signal Strength Indication. RTP ­Real Time Protocol. A thin protocol that supports transmission of real time data (such as interactive voice and video) over packet switched networks.

S
 

SLA ­Service Level Agreement. A contractual agreement between a service provider and a subscriber specifying the QoS parameters (such as MBR) that the subscriber can expect to receive.

SNMP ­Simple Network Management Protocol. The network management protocol used within TCP/IP­based  Internets. Defines the protocol for managers (clients) to communicate with agents (servers).
 

Spread Spectrum ­A coding technique which has the benefit of making a transmission look like noise, so that it causes the minimum interference to other users. Spread spectrum coding also makes the desired signal more rugged so that it is more easily detected in the presence of noise or interference. A key advantage of spread spectrum is that it allows license­free operation in the ISM bands in many countries.

SONET ­Synchronous Optical Network. A standard for high speed digital transmission over fiber optic networks, established by Bellcore and ANSI in the USA. The OC­hierarchy is part of the SONET standard.
 

T
 

T1 ­a specialized circuit developed in the United States for transmission of digital signals over the telephone network at 1.544 Mbps or equivalent to 24 duplex voice circuits. Essentially the same as DS­1.

T3 ­also known as DS­3, 45 Mbps, composed of 28 T1 circuits.
 

TCP ­Transmission Control Protocol A transport layer in the TCP/IP protocol suite that employs handshaking and error checking to ensure that a message is sent accurately and in its entirety.

TCXO ­Temperature Compensated Crystal Oscillator.

 
TDD ­Time Division Duplex. A design in which different timeslots are used for the Tx and Rx channels. Each Access Point uses a single unique frequency spectrum to transmit and receive at different times.

TDMA ­Time Division Multiple Access. A process of combining two or more lower­bandwidth communication channels into a higher­bandwidth channel by allocating frequent time slots in turn to each of the lower bandwidth communications. This technique is used in telephone company networks by which digital facilities are deterministically multiplexed. Thus, for example, the 1.536 Mb/s DS1 payload contains 24 time slots of 64 Kb/s each, corresponding to 24 DS0s. Telnet ­In the Internet, a TCP/IP application that provides virtual terminal services for a wide variety of remote systems.
 

TFTP ­Trivial File Transfer Protocol. A very simple form of the File Transfer Protocol, implemented on top of UDP. TFTP provides no security features. Throughput ­the actual transmission speed of accurate, useful non­redundant traffic over a connection; in many cases connections cannot handle bursts of data due to the limited throughput of the connection and the actual throughput

may be significantly lower than the interface was able to transmit.

U
 

UDP ­User Datagram Protocol. A Transport Layer protocol in the TCP/IP protocol suite that allows an application program on one host to send a connectionless datagram to an application program on another host.

UGS / UGS­AD ­Unsolicited Grant Service. Unsolicited Grant Service – Activity Detection. MAC layer interface services that can be instantiated by a higher level service requester.

 
UNII – Unlicensed National Information Infrastructure. Three bands of spectrum near 5 GHz for unlicensed devices allocated by the FCC under Part 15.401.
 

V
 

VLAN ­Virtual Local Area Network. The ability to associate different LAN­attached workstations as being part of the same LAN independent of where the workstation is physically attached to the LAN.

VoIP / VoP ­Voice over IP. Voice Over Packet. The transport of digitized speech in Internet Protocol packets. The speech may be part of a real­time conversation or a non­real­time transaction such as voice mail.

VoIP Gateway ­A Gateway (a.k.a. Media Gateway, SoftSwitch, Media Gateway Controller, SIP Server, Gatekeeper) is a generic term for a device external to the BWS System that handles VoIP data and signaling traffic.

VPN ­Virtual Private Network. Generally, the use or provisioning of shared network resources in a manner that such resources appear as “private” or dedicated networks to specific users.

VSWR ­Voltage Standing Wave Ratio. The ratio of maximum voltage to minimum voltage along the line. Expresses the degree of match between the transmission line and the terminating element (antenna). When VSWR is 1:1 the match is perfect, a VSWR of 1.5:1 corresponds to 96% power efficiency.

W
 

WAN ­Wide Area Network. A computer or communications network formed by interconnecting LANs that covers a geographic area that is larger than a city or metropolitan area.

Wayside ­Wayside traffic is carried on many microwave radios in addition to the main traffic; wayside channels are used for engineering orderwire circuits, low speed data links, system tests, and in general, facilitating access to signals at intermediate stations. The advantage of wayside provision in that none of the main capacity is compromised for non­revenue traffic required to operate and maintain the system.

WiMAX ­The WiMAX Forum is a non­profit corporation formed to help promote and certify the compatibility and interoperability of BWA (Broadband Wireless Access) equipment.

 
W­OFDM ­Wideband Orthogonal Frequency Division Multiplexing. A spectrally efficient data transport mechanism for the wireless air interface.