ICTRFN406
Maintain hybrid fibre coaxial broadband cable network


Application

This unit describes the skills and knowledge required to conduct routine maintenance tasks, analysing results and initiating corrective action.

It applies to individuals working as field officers from telecommunications carriers, service providers and contractors. They combine a broad range of optical and radio frequency (RF) technical skills with organisational skills to maintain the hybrid fibre coaxial (HFC) broadband cable network, generally with limited supervision and guidance.

Work functions in the occupational areas where this unit may be used are subject to regulatory requirements. Refer to the ICT Implementation Guide Companion Volume or the relevant regulator for details of licensing, legislative or certification requirements.


Elements and Performance Criteria

Elements

Performance Criteria

Elements describe the essential outcomes

Performance criteria describe the performance needed to demonstrate achievement of the element.

1. Prepare for routine maintenance of broadband cable network

1.1 Obtain relevant legislation, codes, regulations and standards for given work

1.2 Determine HFC network elements requiring maintenance and obtain maintenance details from various HFC manufacturer equipment manuals

1.3 Plan detailed routine maintenance schedule and discuss with all relevant personnel

1.4 Notify network operations centre (NOC) of proposed maintenance details and maintenance schedule

1.5 Assess potential impact of proposed maintenance on clients and network, and plan for minimal possible outage or deferral of maintenance

1.6 Obtain necessary tools and resources, and test equipment to undertake maintenance

1.7 Ascertain and record recent network stability and network performance

2. Undertake routine HFC network maintenance tasks

2.1 Conduct routine maintenance tasks according to documented enterprise instructions, following work health and safety (WHS) and environmental requirements, and record results

2.2 Protect network from excessive interference or degradation of service during maintenance routines

2.3 Monitor relevant alarms during running of maintenance tasks and report incidences to NOC

2.4 Escalate unresolved faults according to established enterprise procedure

2.5 Conduct performance measurements following routine maintenance schedule

3. Analyse results and initiate corrective action

3.1 Assess outcomes of performance measurements and maintenance routines to ensure they are according to specification

3.2 Analyse identified problems for likely impact and repair within capability, and initiate or escalate repair action where repair is beyond capability

3.3 Undertake outage if required in conjunction with NOC and according to prescribed enterprise outage plan

3.4 Record problems and incidences in maintenance log for future action as required by maintenance agreement

3.5 Verify alarms to ensure maintenance routines did not generate further problems

Evidence of Performance

Evidence of the ability to:

determine the performance of and maintenance requirements for the hybrid fibre coaxial (HFC) broadband cable

prepare a maintenance schedule and planned activities, and arrange resources

carry out maintenance activities following appropriate procedures and techniques

perform radio frequency (RF) and optical measurements and analyse results

administer corrective measures where required, and verify and document actions

comply with site risk control, work health and safety (WHS), environmental, quality and communication requirements.

Note: If a specific volume or frequency is not stated, then evidence must be provided at least once.


Evidence of Knowledge

To complete the unit requirements safely and effectively, the individual must:

define the following terms: 16 QAM, 64 QAM, 256 QAM

explain the relevance of alternating current (AC) and direct current (DC) electrical equipment in HFC broadband cable network

define forward error correction (FEC) and Reed-Solomon Code

explain bit error ratio (BER) and acceptable values

interpret constellation diagrams

describe digital modulation techniques

summarise Data Over Cable Service Interface Specification (DOCSIS) cable modem characteristics

discuss future broadband cable network (BCN) and migration to all-optical cable networks

outline HFC broadband cable network principles, architecture and associated equipment

outline the minimum standards allowable in the return path for ingress

summarise optical fibre characteristics

explain quadrature phase shift keying (QPSK)

summarise the services carried on the HFC broadband cable network

discuss spectrum utilisation of the return path showing location of telephony and data channels, and signalling and test frequencies

explain video stream transport formats including:

digital video broadcasting (DVB) - asynchronous serial interface (ASI)

high definition serial digital interface (HD-SDI)

motion picture experts group 2 (MPEG-2)

standard definition serial digital interface (SD-SDI)

modulation error ratio (MER) and acceptable values

describe the types of amplifier and placement in a HFC broadband cable network

summarise bi-directional RF amplifier and unidirectional RF amplifier

explain eye diagram interpretation

explain frequency spectrum and RF frequency plan HFC broadband cable network

describe the use of passive devices including filter, attenuator, power inserter, coaxial splitter, coupler, multitap and equaliser

outline the calculation of overall gain or loss when given signal levels in dBmv

summarise coaxial transmission line characteristics including cable tilt or slope

summarise forward path from head end to subscriber showing expected signal levels at key points

outline power supply requirements in a HFC broadband cable network

outline the return path from subscriber to head end showing expected signal levels at key points

discuss RF amplifier characteristics including gain and tilt adjustment, equalisation and overload

outline forms of ingress and where they may fall in the return path

describe the set up, operation and interpretation of test equipment for complex tests including:

optical time domain reflectometer (OTDR)

optical power meter

digital signal level meter

RF sweep equipment

spectrum analyser

identify the hand and power tools required to assemble and disassemble equipment in pits and in elevated work situations.


Assessment Conditions

Gather evidence to demonstrate consistent performance in conditions that are safe and replicate the workplace. Noise levels, production flow, interruptions and time variances should be typical of those experienced in the telecommunications – radio frequency networks field of work and include access to:

sites on which HFC maintenance may be conducted

maintenance tools and test instruments currently used in industry

relevant regulatory, enterprise and equipment documentation that impact on maintenance activities.

Assessors of this unit must satisfy the requirements for assessors in applicable vocational education and training legislation, frameworks and/or standards.


Foundation Skills

This section describes language, literacy, numeracy and employment skills incorporated in the performance criteria that are required for competent performance.

Skill

Performance Criteria

Description

Reading

1.2, 2.1, 2.4, 2.5, 3.3

Recognises and interprets enterprise, regulatory and technical information from relevant sources to determine all specifications and frameworks

Writing

1.3, 1.4, 1.7, 2.1, 3.4

Uses clear, specific and industry related terminology to complete and update workplace documentation and in written communications to relevant personnel

Oral Communication

1.3, 1.4

Liaises with a diverse range of personnel to provide advice and guidance using relevant language

Uses listening and questioning techniques to confirm understanding

Numeracy

2.5

Interprets numerical information and applies basic calculations to conduct performance measurements

Navigate the world of work

2.1, 2.4

Takes personal responsibility for adherence to legal and regulatory responsibilities relevant to own work, with specific reference to safety and environmental requirements

Seeks advice from others when a situation becomes too complex to manage personally

Get the work done

1.1, 1.2, 1.5-1.7, 2.1-2.3, 3.1-3.5

Determines job priorities, resources and equipment and works logically and systematically to undertake clearly defined and familiar tasks

Implements actions according to a predetermined plan, making slight adjustments if necessary and addressing some unexpected issues

Takes responsibility for routine decision making by selecting from a range of predetermined options in routine situations, identifying and taking situational factors into account

Responds to typical problems in different situations and implements standard solutions

Understands the purposes and specific functions of common digital systems and uses them effectively to complete routine tasks

Uses experiences to evaluate and identify improvements for future work


Sectors

Telecommunications – radio frequency networks