E¶

E NodeB¶

Evolved Node B (eNodeB, eNB). The LTE base station. Unlike a UMTS Node B, it has no separate controller: it handles radio resource management and handover itself, and connects directly to the core.

E NodeB

E NodeB.

See also: E-UTRAN, Node B, MME, LTE (4G).

E-UTRAN¶

Evolved UMTS Terrestrial Radio Access Network. The LTE radio access network: eNodeBs and the E-UTRA air interface, which uses OFDMA downstream and SC-FDMA upstream.

E-UTRAN

E-UTRAN.

E.164¶

The ITU-T recommendation for the international public telephone numbering plan. An E.164 number has at most 15 digits, starting with the country code, and is written with a leading +.

EAD¶

Ethernet Access Direct. Openreach’s point-to-point fibre Ethernet circuit, used to connect business sites and for backhaul, at speeds up to 10 Gbit/s.

EAD

EAD.

See also: EoFTTC, Leased Line, Backhaul.

EAP¶

Extensible Authentication Protocol. An authentication framework, defined in RFC 3748, that carries many authentication methods, such as EAP-TLS and PEAP. IEEE 802.1X uses it for network access control on Wi-Fi and wired networks.

EAP

EAP.

Earned Value¶

EV. A measure of progress that compares the value of the work completed with the work planned and its actual cost, to show schedule and cost variance.

Earned Value Management¶

EVM. Managing a project using earned value measures.

Echo¶

A delayed reflection of a signal. On telephone calls it comes from hybrids that convert between 2-wire and 4-wire circuits, or from a loudspeaker feeding back into a microphone. Delay makes it more noticeable.

Echo cancellation¶

Removing echo from a call by modelling the echo path and subtracting an estimate of the echo from the incoming signal. It replaced echo suppression, which muted the return path while the far end was talking. Line echo cancellers handle network echo; acoustic echo cancellers handle loudspeaker-to-microphone echo.

See also: Echo, Echo Cancellation - G.168.

Echo Cancellation - G.168¶

ITU-T Recommendation G.168, which specifies digital network echo cancellers. It covers their performance, how tones disable them for fax and data, and the laboratory tests to check them.

EDB¶

Emergency Database. In UK telephony, the database that tells emergency services the address behind the number calling 999.

EDGE¶

Enhanced Data rates for GSM Evolution. An upgrade to GSM data, also called EGPRS, that uses better modulation and coding to roughly triple GPRS speeds on the same radio channels.

Editor¶

In an inspection, the person who makes the fixes to the artefact afterwards, usually its author.

EFM¶

Ethernet in the First Mile. IEEE 802.3ah, which defines Ethernet over the access link between provider and customer, on copper or fibre, with its own management functions.

Egress¶

Traffic leaving a network or a device, as opposed to ingress traffic coming in.

Egress

Egress.

EIA¶

Electronic Industries Alliance. A former US standards and trade body for electronics manufacturers, known for standards such as RS-232. It closed in 2011 and its work passed to other bodies, including the TIA.

EIGRP¶

Enhanced Interior Gateway Routing Protocol. Cisco’s advanced distance-vector routing protocol, which sends only incremental updates. It replaced IGRP in 1993 and was published as RFC 7868 in 2016.

Embedded systems programming¶

Writing software for an embedded system, a computer built into a device, using the interfaces and limited resources the device provides.

Engineering Discussion¶

A meeting to frame a problem and look for solutions. If materials go out beforehand for people to read, it is closer to a preview.

Engineering Management¶

EM. Planning, staffing, tracking and controlling software projects, together with managing the teams and the organisation.

Engineering Process¶

Software engineering process: defining how software engineering work is done, and improving it.

EoFTTC¶

Ethernet over FTTC. A business Ethernet service over fibre to the cabinet: copper runs from the premises to the street cabinet, and fibre from there to the exchange. It gives symmetrical speeds of tens of megabits per second at lower cost than a fibre leased line.

EoFTTC

EoFTTC.

EoS¶

Ethernet over SDH or SONET. Protocols that carry Ethernet over SDH or SONET networks. They usually use the generic framing procedure (GFP) and virtual concatenation to fit the Ethernet rate into SDH paths.

ePDG¶

Evolved Packet Data Gateway. The LTE core node that lets devices on untrusted non-3GPP access, such as public Wi-Fi, reach the mobile core through an IPsec tunnel. Wi-Fi calling relies on it.

Epic¶

A large user story, too big for one iteration, that is split into smaller stories.

See also: User Stories, Story Splitting.

EPWS¶

Ethernet Private Wire Service. A point-to-point Ethernet service between two customer sites, carried over the provider’s network.

ESB¶

Enterprise Service Bus. Middleware in a service-oriented architecture that connects applications through a shared bus. It routes, transforms and mediates messages between them, so that each application integrates with the bus rather than with every other application.

ESB

ESB.

Estimate¶

The result of estimating: the predicted size, effort, cost or duration, with the inputs, assumptions and method behind it. It can be a full project estimate or a one-line task estimate.

Estimation¶

Working out the likely size, effort, cost, schedule or quality of a project. Several techniques used together give a better estimate than one, and estimates should be redone as the project goes on.

Ethernet over twisted pair¶

Ethernet physical layers that use twisted-pair copper cable. 10BASE-T, 100BASE-TX, 1000BASE-T and 10GBASE-T are the main ones. Single-pair variants, such as 10BASE-T1L, serve industrial and automotive uses.

Ethernet over twisted pair

Ethernet over twisted pair.

Ethernet over twisted pair

Ethernet over twisted pair.

Ethernet over twisted pair.

Ethical Hacking¶

Testing an organisation’s security with its permission, using attackers’ methods to find weaknesses before they do. Ethical hackers are also called white hats.

ETL¶

Extract, Transform, Load. The three steps for moving data into a data warehouse: read data from source systems, convert and clean it into the target form, and write it into the target.

ETL

ETL.

ETSI¶

European Telecommunications Standards Institute. The not-for-profit body, based in Sophia Antipolis in France, that sets European telecoms standards. Its work includes GSM, DECT and TETRA, and it is a founding partner of 3GPP.

EVC¶

Ethernet Virtual Connection. In Metro Ethernet Forum (MEF) terms, the association between two or more customer interfaces (UNIs) across a provider’s network. It is a virtual pipe that defines which sites can exchange frames.

Evolutionary Delivery Lifecycle¶

A lifecycle that combines evolutionary prototyping with staged delivery.

Evolutionary Prototyping Lifecycle¶

A lifecycle in which a system grows from an initial concept through repeated prototypes until it is ready to deliver.

See also: Lifecycle, Iterative Development.

EVPL¶

Ethernet Virtual Private Line. An MEF E-Line service that carries several point-to-point virtual connections over one customer interface, separated by VLAN. Its sibling, Ethernet Private Line (EPL), gives one transparent connection per port.

Expert Judgement¶

Estimating from the experience of people who know the work. It works best when combined with other techniques, such as analogy and decomposition.

See also: Estimation, Analogy Estimation.

Explicit Change Control¶

Change control of artefacts, such as requirements and plans, that a change control board manages directly.

Explicit Risk Management¶

See Extrinsic Risk Management.

Exploratory Testing¶

Testing in which the tester learns about the software, designs tests and runs them all at once, rather than following a script.

Extrinsic Risk Management¶

Formal risk management added to a project, such as keeping a top-ten risk list and reviewing it regularly.