-SWQ-SCOTTISH QUALIFICATIONS AUTHORITY HIGHER NATIONAL UNIT SPECIFICATION GENERAL INFORMATION SATELLITE COMMUNICATION TECHNOLOGY

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1 -SWQ-SCOTTISH QUALIFICATIONS AUTHORITY HIGHER NATIONAL UNIT SPECIFICATION GENERAL INFORMATION -Unit Number Superclass- -Title- XM SATELLITE COMMUNICATION TECHNOLOGY DESCRIPTION- GENERAL COMPETENCE FOR UNIT: Describing the operation of a satellite communication system and calculate associated parameters. OUTCOMES 1. describe and state the basic properties of a satellite communication system; 2. describe and calculate the properties of a satellite communications link; 3. describe the methods of sharing the satellite communication channels; 4. describe the ground station and satellite communication and control equipment. CREDIT VALUE: 1 HN Credit ACCESS STATEMENT: Access to this unit is at the discretion of the centre. However it would be beneficial if the candidate had prior knowledge of basic communication theory. This may be evidenced by the possession of HN Units: Telecommunication Fundamentals Communication Principles: Modulation and Demodulation or similar qualifications or experience For further information contact: Committee and Administration Unit, SQA, Hanover House, 24 Douglas Street, Glasgow G2 7NQ. Additional copies of this unit may be purchased from SQA (Sales and Despatch section). At the time of publication, the cost is 1.50 (minimum order 5.00).

2 HIGHER NATIONAL UNIT SPECIFICATION STATEMENT OF STANDARDS UNIT NUMBER: UNIT TITLE: SATELLITE COMMUNICATION TECHNOLOGY Acceptable performance in this unit will be the satisfactory achievement of the standards set out in this part of the specification. All sections of the statement of standards are mandatory and cannot be altered without reference to SQA. OUTCOME 1. DESCRIBE AND STATE THE BASIC PROPERTIES OF A SATELLITE COMMUNICATION SYSTEM PERFORMANCE CRITERIA (a) (b) (c) (d) Applications of satellite communication systems are clearly and Satellite communication systems are compared with other communication systems. The parameters associated with a satellite in orbit are clearly and The frequency bands used in satellite communications are correctly stated. RANGE STATEMENT Applications: communications; navigation; weather; surveillance. Comparison between satellite and other systems to include: point-to-multipoint; installation; relocation; network failure. Parameters: satellite heights; range and footprint. Frequency bands: C; X; Ku; K; Ka. EVIDENCE REQUIREMENTS Written, pictorial and/or tabular presentation evidence of the candidate s ability to describe the basic properties of a satellite communication system. 2

3 OUTCOME 2. DESCRIBE AND CALCULATE THE PROPERTIES OF A SATELLITE COMMUNICATIONS LINK PERFORMANCE CRITERIA (a) (b) (c) The properties of satellite communications antennae are clearly and The losses over a typical propagation path are clearly and correctly described and calculated. The effects of noise on a satellite communication link are clearly and correctly described and calculated. RANGE STATEMENT Antennae properties: radiation pattern; beamwidth; gain; polarisation; isolation. Propagation losses: atmospheric attenuation; rain attenuation; polarisation; scattering; diffraction. Noise: natural; man made; interference. Link calculation: signal to noise ratio; carrier to noise ratio; link budget. EVIDENCE REQUIREMENTS Written and diagrammatic evidence of the candidate s ability to describe the properties of a satellite communications link as specified in performance criterion (a). Written and graphical evidence of the candidate s ability to describe the properties of a satellite communication link as specified in performance criteria (b) and (c). Evidence of the correct principle of calculation of the parameters of a satellite communications link is required for performance criteria (b) and (c). OUTCOME 3. DESCRIBE THE METHODS OF SHARING THE SATELLITE COMMUNICATION CHANNELS PERFORMANCE CRITERIA (a) (b) Frequency division multiplexing techniques employed by satellite communication systems are clearly and Time division multiplexing techniques employed by satellite communication systems are clearly and 3

4 (c) (d) The principles of packet switching techniques are clearly and Multi-access techniques are clearly and RANGE STATEMENT Packet switching: data; error coding; addresses; control. Multi-access techniques: frequency division multiple access; time division multiple access; demand access; spread spectrum. EVIDENCE REQUIREMENTS Written and diagrammatic evidence of the candidate s ability to describe the basic properties of a satellite communication system, as specified in performance criteria (a), (b), (c) and (d). OUTCOME 4. DESCRIBE THE GROUND STATION AND SATELLITE COMMUNICATION AND CONTROL EQUIPMENT PERFORMANCE CRITERIA (a) (b) (c) The basic elements in a transponder are clearly and correctly described. The main elements in an earth station transmitter are clearly and The main elements in an earth station receiver are clearly and RANGE STATEMENT Transponder elements: antennae; amplifiers; frequency converter; filters. Earth station transmitter: modulator; antennae; amplifiers; control. Earth station receiver: demodulator; antennae; amplifiers; filters. EVIDENCE REQUIREMENTS Written and diagrammatic evidence of the candidate s ability to describe the basic properties of a satellite communication system, as specified in performance criteria (a), (b) and (c). MERIT To gain a pass in this unit, a candidate must meet the standards set out in the outcomes, performance criteria, range statements and evidence requirements. 4

5 To achieve a merit in this unit, a candidate must demonstrate a superior or more sophisticated level of performance. This may be demonstrated by: (i) more in depth description of the principles involved in a satellite communication system ASSESSMENT In order to achieve this unit, candidates are required to present sufficient evidence that they have met all the performance criteria for each outcome within the range specified. Details of these requirements are given for each outcome. The assessment instruments used should follow the general guidance offered by the SQA assessment model and an integrative approach to assessment is encouraged. (See references at the end of support notes). Accurate records should be made of the assessment instruments used showing how evidence is generated for each outcome and giving marking schemes and/or checklists, etc. Records of candidates achievements should be kept. These records will be available for external verification. SPECIAL NEEDS Proposals to modify outcomes, range statements or agreed assessment arrangements should be discussed in the first place with the external verifier. Copyright SQA 1997 Please note that this publication may be reproduced in whole or in part for educational purposes provided that: (i) (ii) no profit is derived from the reproduction; if reproduced in part, the source is acknowledged. 5

6 HIGHER NATIONAL UNIT SPECIFICATION SUPPORT NOTES UNIT NUMBER: UNIT TITLE: SATELLITE COMMUNICATION TECHNOLOGY SUPPORT NOTES: This part of the unit specification is offered as guidance. None of the sections of the support notes is mandatory. NOTIONAL DESIGN LENGTH: SQA allocates a notional design length to a unit on the basis of time estimated for achievement of the stated standards by a candidate whose starting point is as described in the access statement. The notional design length for this unit is 40 hours. The use of notional design length for programme design and timetabling is advisory only. PURPOSE The purpose of this unit is to enable candidates to demonstrate a basic understanding of the principles involved in satellite communications systems. It is aimed at those with an interest in broadening their knowledge of communication systems and who have a basic knowledge of general communications techniques and systems. CONTENT/CONTEXT Corresponding to outcomes: Outcome 1 PC (a) PC (b) PC (d) When describing applications only a general understanding need be demonstrated, for example when a candidate describes a navigation satellite system he/she should describe how the signals from several satellites are interpreted by the receiver to fix the position and altitude of the receiver on earth. Comparisons between communications systems and satellite systems should be general and could take account of cost, ease of implementation, mobility, efficiency etc. Comparison of 3 or 4 different communication systems would be adequate for example, a sky wave system and a land line system could be compared with a satellite system. The frequency ranges associated with frequency bands listed in the range statement should be stated. 6

7 Outcome 2 PC(b) PC(c) Calculation of loss due to various conditions taking account of propagation path length should be carried out. Total loss due to all factors could also be calculated over a given propagation path. PC(a) requires the use of Loss db = 10 log (attenuated signal power/transmitted signal power). Signal to noise ratio and carrier to noise ratio could be calculated for a given system. PC(b) requires the use of: Outcome 4 SNR db= 10 log (S/N) CNR db = 10 log (C/N) Descriptions should be restricted to functional blocks making use of block diagrams of transmitter, receiver and transponder. The description should cover the purpose of each functional block in the system. APPROACHES TO GENERATING EVIDENCE Candidate-centred research and formal lecture is recommended. Use of several information sources should be encouraged eg. computer software, video, books etc. Formulae, where required, should be supplied. ASSESSMENT PROCEDURES Outcome 1 Instrument of Assessment could be the production of a suitable report or a written response to a question. Outcome 2 PC (a) - A written answer or report could be suitable method of assessment. PC (b) and (c) - Production of a list of losses. A written description of the effect of noise. Outcome 3 All performance criteria written answers or reports could be suitable method of assessment. Outcome 4 All performance criteria written answers or reports could be suitable method of assessment. PROGRESSION This is a standalone unit which does not lead to any other specific HN unit. 7

8 REFERENCES 1. Guide to unit writing. 2. For a fuller discussion on assessment issues, please refer to SQA s Guide to Assessment. 3. Information for centres on SQA s operating procedures is contained in SQA s Guide to Procedures. 4. For details of other SQA publications, please consult SQA s publications list. Copyright SQA 1997 Please note that this publication may be reproduced in whole or in part for educational purposes provided that: (i) (ii) no profit is derived from the reproduction; if reproduced in part, the source is acknowledged. 8