Principles of Radio Site Engineering

Course Overview

For those new to radio site surveying, site build or site maintenance, the equipment and requirements for an effective radio site can be bewildering. Becoming familiar with the enormous variety of antenna types, feeder configurations and connections, radio equipment options and terrestrial communications arrangements can take a long time. Understanding what all these components do, why they are there and how they all fit together is even more of a challenge.

This course provides a theory-based guide to the requirements of a radio site and all the equipment to be found at a typical radio site. This includes a brief but comprehensive introduction to the principles of radio transmission, reception and radio coverage techniques. The course builds on these basic principles to cover all key equipment types found at typical outdoor and indoor cellular radio sites, from the sensitive radio components to the tower structure itself.

Audience

• This course is designed for engineers and surveyors working for site acquisition and maintenance companies or directly for network operators. Students are likely to be new to the requirements of site survey, acquisition or build.
• This course is also useful for those not directly involved with radio sites but who will be working in radio-site-related areas. This includes radiorelated tender processes, Government security or forensic work, legal professionals supporting network operators or equipment manufacturers or local authorities, support staff and those managing technical teams.

Skills Gained

On completion of this course the student will be able to:

• explain how a signal is radiated from an antenna and characterise the transmitted signal
• describe how radio waves are propagated and explain how the transmission frequency is related to coverage
• characterize the effect on radio propagation resulting from variations in terrain and ground clutter
• compare the three most common multiple access schemes, FDMA, TDMA and CDMA
• describe transmission line characteristics and explain how they apply in radio systems
• characterise the performance of an antenna in terms of gain, beamwidth, bandwidth and front-to-back ratio
• describe the characteristics of antennas used in cellular networks and their configurations on a radio site
• describe the effects of metal support structures, masts and buildings on antenna performance
• explain how effects such as interference and fading occur and how they can be combated
• describe the requirements of cellular networks in terms of coverage and frequency reuse
• describe techniques that allow for in-building coverage
• identify radio components used in typical single and multi-technology
• identify physical, safety and legal factors to be considered when identifying a potential site

Prerequisites

No prior knowledge of radio principles is required, but it is assumed that students will have a technical backbround, or a good ability to comprehend technical information.

Course Outline

Radio Theory and Propagation

• Radio theory
• The Electromagnetic (EM) spectrum
• Multiple access techniques
• TDMA/FDMA combination
• Radio wave propagation
• Radio refractive index
• Refractivity
• Effects of refraction
• Free space propagation
• Effective aperture and received power
• Free Space Path Loss (Lfs)
• Multipath propagation
• The urban and rural environments
• Fading
• Diversity reception
• Polarisation diversity
• Time dispersion
• Techniques to combat time dispersion
• The rake receiver
• The principles of rake receiving
• Transmit diversity
• Closed loop modes
• Frequency hopping

Antennas and Feeders

• Antenna theory
• Reciprocity theorem
• The isotropic radiator
• The half-wave dipole
• Radiation patterns
• Antenna polarization
• Antenna gain
• The folded dipole
• The Yagi antenna
• Directional antenna gain
• Effective Radiated Power (ERP)
• Antenna beamwidth and bandwidth
• Cross polar discrimination
• Front-to-back ratio
• Sidelobe response
• Stacking and baying
• Omnidirectional antennas
• Sector antennas
• Antenna downtilt (beamtilt)
• Antenna configurations
• Microwave antennas
• Antenna alignment
• Transmission lines
• Coaxial cables
• Impedance matching for maximum power transfer
• Standing waves
• Waveguides
• Feeder protection
• Optical fibre
• Advantages of optical systems
• Optical fibre construction
• A simple optical fibre transmission link
• Optical safety guidelines
• Effects of metal support structures
• Other mounting considerations

Cellular Coverage Areas

• Traditional coverage methods
• The cellular philosophy
• Frequency reuse
• Interference
• Reuse distance
• System growth
• The UMTS radio environment
• Overlaid/underlaid cells
• Cell dimensions and positioning
• Urban areas
• Traffic routes
• Cell boundaries
• Macro cells
• Micro cells
• Providing coverage from an outside site
• Cell repeaters
• Dedicated BTS (pico cell)
• Leaky feeder
• Distributed antenna system
• Fibre systems
• A practical optical system

Radio Interference Problems and Solutions

• Radio system interference
• Intermodulation
• Frequency isolation
• Multi-site configurations
• Radio Frequency (RF) requirements
• Antenna system solutions
• Antenna feeder sharing
• Separation from other operators' antennas

Site Engineering Requirements

• Radio site selection
• Coverage planning
• Traffic levels
• Surveying prospective radio sites
• Verification of site by measurement
• Earthing
• Lightning protection
• UK planning issues
• RF emission limits and safety

Follow On Courses

Students may find our radio technology system overview courses useful. Technologies covered include GSM, GPRS, UMTS, TETRA, cdmaOne, CDMA2000, wireless LANs and fixed radio links. Those involved in terrestrial communications links for radio sites may benefit from Digital Radio and Microwave Link Planning, SDH Principles, ATM Principles, TCP/IP Protocol Suite, or MPLS Overview.

Principles of Radio Site Engineering / RP2100