PATHLOSS IV TRAINING
Course Objectives After completing this training, the participants shall be able to: • • • •
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Create and edit path profile using manual data entries and/or digital terrain models, Calculate antenna heights and separations using well specified clearance criteria, Calculate both multipath and rain related Performance and Availability percentages of the link and evaluate them with respect to ITU-R Recommendations, Analyze the effect of a single specular reflection on the path and choose suitable countermeasures, Assess diffraction losses resulting from changing refractive index gradient on low clearance hops, Perform intrasystem interference calculations and ensure their frequency plans are kept free from harmful threshold degradations, Generate suitable set of data required by installation technicians and operation personnel.
Course Overview This course offers a comprehensive and highly technical hands-on-computer training related to planning of point-to-point microwave links and networks, using an advanced planning software tool Pathloss 4.0. Key Benefits Participants of this course will be able to plan microwave point-to-point links using software planning tool Pathloss 4.0, including ability to analyse data from path surveys, create respective profile data and decide upon antenna heights, calculate Performance and Availability percentages of the link and optimise them with respect to the ITU-R objectives as well as cost-effectiveness. They will be able to perform frequency planning for large networks, avoiding their design to suffer from harmful interference. Pre-Requisites for Participants Basic knowledge of theoretical principles of radio propagation governing the design of MW Point-to-Point links, including respective ITU-T, ITU-R Recommendations. A licenseactivated copy of Pathloss 4.0 installed on laptop computer.
Course Outline Day 1: Introduction to PathLoss 4.0: Planning Concept, Basic Parameters, Generated Reports, Types of Digital Terrain Models (DTM), Coordinate Systems (Datum, Ellipsoids, Grid). Hop Definition: Summary Module, Equipment Lookup Table, Antenna Lookup Table, Frequency Channels Table, Earth Radius Representation in Profiles. Network Description: Network Overview, Site List, Link List, Background and 3D View Generation. Terrain Profiling and Diffraction Losses: Generating Terrain Profile, Choosing Clearance Criteria, Antenna Centre-line Calculation, Diffraction Module Overview, (Radius Method, Multiple Knife-edge Methods), Total Diffraction Loss Concept, Diffraction Parameters, Case study for diffraction. Day 2: Microwave Worksheet: Net Pathloss Components, Free Space Loss and Atmospheric Absorption, Multipath Propagation Reliability Prediction Models (Vigants – Barnett, ITU-R P.530-6, ITU-R P.530-7, ITU-R P.530-9, K.Q Factor), Terrain Roughness Calculations, Grazing Angle, Rayleigh Fading Probability, Diversity Options (SD Baseband Switching, SD IF Combining), Rain Attenuation Models (Crane, ITU-R P.530), Polarization Considerations, Rain Related Fade Margin. Case studies for various frequency bands and both ITU-T G.821 and ITU-T G.826/828 related objectives. Applying Diversity and Protection: Diversity Improvement Models, Variable Parameters, Hybrid Diversity combining models. Multipath Operation: Constant Gradient Trace, Variable Gradient Trace, Annual versus Worst Month Statistics. Reliability versus Performance and Availability. Day 3: Design with Passive Repeater: Plane Reflector PR, Back-to-back Antenna PR, Case studies for PR. Reflection Analysis and Multipath Operations: Reflective Plane Definition, Two Ray Optics, Terrain Roughness and Clutter, Dispersion
Analysis, Modifying Reflection Parameters, Countermeasures and Case study. Applying Diversity and Protection: Diversity Improvement Models (Space Diversity, Frequency Diversity, Angle Diversity), Variable Parameters, Case study for SDH hops. Intra-system Interference: Interference Calculation Procedure, Repeated Analysis Method for Frequency Planning, Interference Reports, Cross-Polarization Interference. Case studies on extensive GSM/GPRS related MW transmission networks.
