Site Survey

A Site Survey is an assessment of a location carried out to determine whether a two-way radio systemA Radio System is a complete communication solution comprising two-way radios and, where required, equipment such as repeaters, antennas, base stations, mobile radios and network infrastructure. will provide the required coverageRadio Coverage is the geographical area in which a two-way radio system can provide reliable communication. Coverage depends on the radios, antennas, frequency, terrain, buildings and system infrastructure., reliability and performance.

A professional radio site survey examines the physical environment, radio coverage, potential sources of interferenceRadio interference occurs when unwanted radio-frequency signals or electrical noise disrupt two-way radio communications, causing distorted audio, broken transmissions, reduced coverage or loss of communication. and the requirements of the users. It can be used to determine whether direct radio communication is sufficient or whether additional infrastructureRadio infrastructure is the equipment and supporting systems behind a professional two-way radio network, including repeaters, antennas, base stations, network connections, power systems and dispatch equipment., such as a RepeaterA Repeater receives a two-way radio transmission and retransmits it, usually from an elevated location, to extend the coverage and reliability of a radio communication system., external antennaAn antenna transmits and receives radio-frequency signals, allowing a two-way radio to communicate. Antenna type, frequency, height and location can all affect radio performance and coverage. or multi-site system, is required.

What is a radio site survey?

A radio site survey involves testing the proposed operating area to understand how radio signals behave across the site.

Depending on the application, an engineer may assess:

• Indoor coverage
• Outdoor coverage
• Building-to-building coverage
• Vehicle coverage
• Dead spots
• Signal strength
• Interference
• Terrain
• Building construction
• Antenna locations
• Repeater locations

The objective is to establish whether the proposed radio system can meet the required operational coverage.

Why is a site survey important?

Radio coverage cannot always be predicted accurately from distance or manufacturer specifications alone.

BuildingsAn antenna transmits and receives radio-frequency signals, allowing a two-way radio to communicate. Antenna type, frequency, height and location can all affect radio performance and coverage., terrain, steelwork, concrete, vegetation and other factors can significantly affect radio propagation.

A site survey provides practical information about the actual environment and can help prevent coverage problems after a radio system has been installed.

What does a radio site survey test?

The exact tests depend on the project, but a survey may examine:

1. Radio signal strength.
2. Communication quality.
3. Coverage boundaries.
4. Indoor penetration.
5. Outdoor coverage.
6. Interference.
7. Antenna locations.
8. Repeater locations.
9. Terrain.
10. Building attenuation.
11. Required radio infrastructure.

Site survey and radio coverage

One of the main purposes of a site survey is to establish the usable coverage area of the radio system.

An engineer may move around the site with test equipment or radios and record where communication is reliable and where it becomes weak or unavailable.

The results can then be used to identify potential coverage gaps.

Site survey and RSSI

RSSI (Received Signal Strength Indicator)RSSI (Received Signal Strength Indicator) is a measurement of the strength of a radio signal received by a two-way radio or other wireless device, commonly used to assess coverage and diagnose reception problems. can be used during a site survey to measure received radio signal strength.

RSSI readings can help show how signal strength changes across the site.

However, RSSI alone does not determine whether communication will be reliable. Signal quality, interference and other RF characteristics must also be considered.

Site survey and signal strength

Signal strength normally decreases as the distance from a transmitter increases, but the relationship is affected by the environment.

A site survey can identify areas where signal strength falls below the level required for the intended radio system.

Site survey and dead spots

A Dead SpotA Dead Spot is an area where two-way radio communication is weak, unreliable or unavailable. Dead spots can be caused by buildings, terrain, distance, interference or inadequate radio coverage. is an area where reliable radio communication cannot be maintained.

Dead spots can be caused by:

• Buildings
• Concrete
• Steel
• Terrain
• Underground areas
• Poor antenna positioning
• RF interference
• Distance

A site survey can identify these areas before or during system deployment.

Site survey and buildings

Building construction can have a major effect on radio coverage.

Materials such as reinforced concrete, steel and metal-clad structures can significantly attenuate radio signals.

A survey may therefore test different floors, rooms, corridors, stairwells, basements and external areas.

Site survey and indoor coverage

Indoor radio coverage can be more difficult to predict than open outdoor coverage.

A site survey can determine whether handheld radios can communicate reliably:

• Inside buildings
• Between floors
• In basements
• In stairwells
• In plant rooms
• In enclosed areas

Where coverage is inadequate, additional infrastructure may be required.

Site survey and outdoor coverage

Outdoor surveys can assess coverage across:

• Car parks
• Yards
• Fields
• Roads
• Construction areas
• Event spaces
• Industrial sites

Terrain and obstructions can create unexpected weak areas.

Site survey and terrain

Hills, valleys and other geographical features can affect radio propagation.

This is particularly important for large outdoor sites such as farms, estates, construction projects and events.

A repeater positioned at a suitable elevated location may improve coverage.

Site survey and radio frequency

A site survey can help assess whether the proposed frequencyAn antenna transmits and receives radio-frequency signals, allowing a two-way radio to communicate. Antenna type, frequency, height and location can all affect radio performance and coverage. is suitable for the intended environment.

FrequencyFrequency is the number of cycles a radio wave completes each second, measured in Hertz. In two-way radio, frequency determines where a transmission operates within the radio spectrum. planning should consider existing radio users and potential sources of interference.

For licensed professional radio systems, frequency use must comply with the relevant UK regulatory requirements.

Site survey and interference

A survey can identify potential Interference affecting radio communications.

Possible sources include:

• Other radio systems
• Electrical equipment
• Industrial machinery
• Wireless equipment
• Nearby transmitters
• RF congestion

Identifying interference can help determine whether frequency or system changes are required.

Site survey and receiver performance

The receiver’s sensitivity affects how well a radio can operate with weak signals.

A survey should therefore be interpreted alongside the specifications and requirements of the radio equipment being considered.

Site survey and transmitter power

Transmitter powerAn antenna transmits and receives radio-frequency signals, allowing a two-way radio to communicate. Antenna type, frequency, height and location can all affect radio performance and coverage. can affect coverage, but simply increasing power is not always the best solution.

Antenna height, antenna performance, frequency, terrain and building attenuation can be equally or more important.

A survey helps determine the most appropriate solution.

Site survey and antennas

A survey can help determine where antennas should be installed.

Factors can include:

• Antenna height
• Building position
• Line of sight
• Cable routes
• Structural constraints
• Lightning protection
• Access for maintenance

Correct antenna positioning can have a significant effect on system performance.

Site survey and repeater location

For systems requiring a Repeater, the survey can help identify an appropriate installation location.

A suitable repeater location may provide improved coverage because of:

• Greater antenna height
• Better line of sight
• Central positioning
• Reduced obstruction
• Better access to power and infrastructure

Site survey and repeater coverage

A repeater can receive a transmissionTransmission is the process of sending voice, data or signalling from a radio using a radio-frequency signal to another radio, repeater or communication system. from one radio and retransmit it so that another radio can receive it.

A survey can establish whether one repeater is sufficient or whether additional infrastructure is required.

Site survey and simplex

A survey can determine whether SimplexSimplex is a method of two-way radio communication where radios transmit and receive on the same frequency, communicating directly without a repeater. radio communication is sufficient.

If radios can communicate reliably throughout the required operating area without infrastructure, a direct radio-to-radio system may be appropriate.

If coverage is inadequate, a repeater or other system architecture may be considered.

Site survey and DMR

A Digital Mobile Radio (DMR)Digital Mobile Radio (DMR) is an ETSI digital radio standard for professional two-way communications, supporting voice, group calling, data and other features on compatible radio systems. site survey can assess whether a proposed DMR system provides suitable coverage.

Testing can include:

• Digital voice quality
• Signal strength
• Coverage
• Interference
• Repeater performance
• Indoor penetration

Digital systems can behave differently from analogue systems, so testing should use the actual or representative equipment where possible.

Site survey and analogue radio

Analogue radioAnalogue radio uses continuously varying radio signals to transmit voice communication. It remains widely used for reliable two-way communication across business, industry, events, security and other applications. systems can also be tested through a site survey.

An engineer can assess voice quality, signal strength, noise and interference throughout the operating area.

Site survey and digital radio

Digital radio systems may produce clear audio over a range of signal conditions before communication begins to degrade rapidly as the signal becomes insufficient.

A survey should therefore consider digital performance rather than relying solely on perceived audio quality.

Site survey and radio testing

A practical radio test may involve two or more radios positioned at different points around the site.

The engineer can record whether communication is:

• Clear
• Usable
• Intermittent
• Unreliable
• Unavailable

This information can be used to develop a coverage plan.

Site survey and coverage mapping

Survey results can be plotted on a map or floor plan to show the areas where the radio system provides acceptable coverage.

A coverage map can highlight:

• Strong coverage
• Weak coverage
• Dead spots
• Building problem areas
• Repeater coverage
• Outdoor coverage

Site survey and large buildings

Large buildings often require detailed surveys because radio signals can behave differently on different floors and in different parts of the building.

Examples include:

• Hotels
• Hospitals
• Shopping centres
• Warehouses
• Stadiums
• Office buildings
• Industrial facilities

Site survey and underground areas

Basements, tunnels and underground car parks can be particularly difficult for conventional radio systems.

A survey can determine whether the existing system provides sufficient coverage or whether specialist infrastructure is required.

Site survey and warehouses

Warehouses can present specific radio challenges because of:

• Metal racking
• Large floor areas
• High ceilings
• Machinery
• Loading bays
• Multiple buildings

A site survey can identify coverage problems before deployment.

Site survey and construction sites

Construction sites change continually as buildings are constructed.

Temporary structures, cranes, steelwork and newly completed sections can alter radio propagation.

A survey may therefore need to be repeated as the project develops.

Site survey and security

Security operations often require reliable coverage across both indoor and outdoor areas.

A survey can assess communication between:

• Security officers
• Patrols
• Supervisors
• Control rooms
• Entrances
• Car parks

Site survey and events

Temporary events can require radio coverage across large or complex areas.

A site survey can assess:

• Event grounds
• Stages
• Back-of-house areas
• Entrances
• Car parks
• Security areas
• Control rooms

This can help determine the appropriate radio and repeater configuration.

Site survey and radio hire

A site survey can be particularly useful for Radio HireRadio Hire is the temporary rental of two-way radios and related communication equipment for events, projects and operational requirements, providing professional communication without purchasing the equipment. deployments.

For temporary events or projects, testing can help determine:

• Number of radios required
• Whether a repeater is needed
• Where the repeater should be positioned
• Which accessories are appropriate
• Whether additional infrastructure is required

Site survey and security radio hire

Temporary security operations can require reliable communication across a venue or site.

A pre-event survey can identify weak areas and allow the radio hire system to be configured accordingly.

Site survey and fleet operations

For vehicle-based operations, a survey can assess communication along roads, across depots or throughout operational areas.

The survey can also consider the performance of vehicle-mounted Mobile Radios and their antennas.

Site survey and agriculture

Large farms and estates can have challenging terrain and significant distances between users.

A survey can establish whether handheld radios provide sufficient coverage or whether a repeater is required.

Site survey and transport

Transport depots, yards and terminals can require reliable communication across large operational areas.

A survey can identify weak areas caused by buildings, vehicles, structures and terrain.

Site survey and emergency communications

Where radios are used for emergency or safety-critical communications, coverage requirements should be defined carefully.

A survey can help establish whether the system provides the required level of coverage throughout the operational area.

Critical systems may require additional resilience or infrastructure.

Site survey and redundancy

A survey can also consider the resilience of the proposed radio infrastructure.

For critical applications, the system may require:

• Backup power
• Additional coverage
• Redundant equipment
• Alternative communication methods

Site survey and GPS

GPS (Global Positioning System)GPS is a satellite-based positioning system that allows compatible two-way radios to determine their location. GPS data can support tracking, dispatch, fleet management and Geo-Fencing. can be used alongside radio coverage testing.

A radio’s location can be recorded together with signal measurements, allowing engineers to associate coverage results with specific geographical positions.

Site survey and geo-fencing

Where a radio system supports location services, Geo-FencingGeo-Fencing uses GPS and a virtual geographical boundary to identify when a radio user or tracked device enters or leaves a defined area, triggering alerts or other actions where supported. can be used to define geographical areas.

This is separate from the RF coverage survey but can be incorporated into wider system planning.

Site survey and radio licensing

In the UK, professional radio frequencies are regulated by OfcomOfcom (Office of Communications) is the UK's communications regulator. For two-way radio users, Ofcom manages and regulates access to radio spectrum and the use of radio frequencies in the UK..

A site survey can form part of the planning process for a licensed business-radio system, but the survey itself does not constitute a radio licence.

The appropriate licence must be obtained where required.

Site survey and Ofcom

Ofcom manages the UK’s radio spectrumSpectrum is the range of radio frequencies used for wireless communication. Two-way radios operate within specific parts of the radio spectrum, subject to frequency allocation and licensing requirements. and regulates the use of radio frequencies.

Frequency selection and licensing should be considered alongside the technical requirements identified during a site survey.

Site survey and system design

The results of a site survey can influence the final radio system design.

For example:

Survey → Coverage requirement → Equipment selection → Repeater/antenna design → Installation → Testing

This approach helps ensure that the system is designed around the actual environment.

Site survey before installation

A pre-installation survey can identify potential problems before equipment is purchased or installed.

This can reduce the risk of discovering significant coverage gaps after deployment.

Site survey after installation

A post-installation survey can verify that the completed system performs as expected.

Testing can compare actual coverage with the original design requirements.

Site survey and acceptance testing

For larger radio projects, coverage testing can form part of system acceptance.

The installed system can be tested against agreed performance criteria before being handed over to the customer.

Site survey report

A professional site survey may produce a report containing:

• Site information
• Survey methodology
• Equipment used
• Frequencies tested
• Coverage results
• Signal measurements
• Problem areas
• Coverage maps
• Interference findings
• Recommendations

The level of detail depends on the project.

Site survey recommendations

A survey may recommend measures such as:

• Repeater installation
• Repeater relocation
• Improved antenna height
• Different antenna configuration
• Additional infrastructure
• Frequency changes
• Alternative radio technology
• Additional coverage testing

The recommendation should address the cause of the coverage problem rather than simply increasing transmitter power.

Site survey limitations

A site survey represents conditions at the time of testing.

Radio conditions can change because of:

• Building alterations
• New equipment
• New structures
• Vegetation
• Other radio users
• Changes to the radio system

For temporary or changing environments, additional testing may be appropriate.

When is a site survey required?

A site survey is particularly useful where:

• Reliable coverage is important.
• The site is large.
• Buildings are complex.
• Terrain is challenging.
• Multiple buildings need to communicate.
• A repeater is being considered.
• The radio system is safety-critical.
• Existing coverage is unreliable.
• A new permanent radio system is being installed.

For a small, straightforward operation using direct radio communication, a formal survey may not always be necessary.

Site survey and DCS

DCS can carry out radio coverage assessments and site surveys to determine the appropriate two-way radio solution for a particular location.

Survey results can be used to recommend suitable radios, antennas, repeaters and other infrastructure based on the site’s physical environment and communication requirements.