Call Group

A Call Group is a predefined group of two-way radio users who can communicate with one another using a shared radio channelA two-way radio channel is a programmed set of communication settings, typically including frequency and signalling, that allows compatible radios to communicate with one another. or talkgroup. Call Groups allow organisations to divide users into specific teams or departments so that communications can be directed to the people who need to hear them.

Call Groups are particularly common on digital two-way radio systems, including DMR, where radios can be programmed with multiple groups and users can select the appropriate group for their current activity.

For example, a business might have separate Call Groups for security, maintenance, management and operations.

How does a Call Group work?

A Call Group is created by configuring compatible radios so that they share the same group identity or talkgroup.

When a user selects that group and presses the Push-to-Talk (PTT)Push-to-Talk (PTT) is the button or control used to activate a two-way radio's transmitter. Press it to speak and release it to listen. button, the 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. is delivered to the other radios configured to receive that group.

A simplified example is:

User A → Call Group → Users B, C and D

Users outside that Call Group will normally not hear the communication, provided the 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. has been configured accordingly.

The exact operation depends on the radio technology and system configuration.

Call Groups and talkgroups

The terms Call Group and Talkgroup are often used interchangeably, particularly in digital radio systems.

A talkgroup is essentially a logical group of radio users who share communications.

The terminology varies between manufacturers and radio platforms. Some systems may refer to a group as a Call Group, while others use terms such as Talkgroup, Group Call or Group ID.

The underlying principle is the same: communications are directed to a defined group of users rather than being sent to every radio on the system.

Call Groups in digital radio

Call Groups are particularly useful with digital radio because digital systems can identify individual radios and groups using programmed IDs.

Technologies such as DMR (Digital Mobile RadioA Mobile Radio is a two-way radio designed to be installed in a vehicle. It normally uses the vehicle's power supply and an external antenna to provide reliable communication while travelling or working in the field.) can support multiple group identities, allowing one radio to communicate with different teams without requiring a separate physical radio for each group.

For example, a single radio could be programmed with:

• Security
• Maintenance
• Operations
• Management
• Emergency

The user can then select the appropriate group when communication is required.

Call Group vs individual call

A Call Group is intended for communication with multiple users.

An Individual Call is directed towards one specific radio.

For example:

Group Call: Security supervisor → entire security team

Individual Call: Security supervisor → one security officer

Both functions can be available on professional digital radio systems, allowing users to choose between communicating with an entire team or contacting one person directly.

Call Groups and shared radio channels

On simpler radio systems, groups of users may share the same physical radio channel.

In a digital system, several logical groups can potentially operate using the available radio resources, depending on the technology and configuration.

This allows an organisation to structure communications without necessarily requiring a completely separate 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. for every department or team.

On a DMR system, for example, talkgroups can be assigned to the available timeslots, allowing multiple groups to share radio resources efficiently.

Call Groups and DMR

DMR supports Group Calls, allowing a radio user to communicate with a defined group of radios.

Each group can be assigned a specific Group ID within the radio system.

The radios are programmed with the appropriate group information so that users can select and communicate with the relevant team.

This is one of the reasons DMR is widely used for professional radio systems where different departments or teams need separate communication channels.

Call Groups and radio programming

Call Groups are created through the programming and configuration of the radio system.

Programming can determine:

• Which Call Groups are available
• The name displayed for each group
• The Group ID
• Which channels or timeslots are used
• Which radios can access each group
• Which groups each radio can receive
• Priority and scanning behaviour

Correct programming is important because incorrectly configured radios may be unable to communicate with the intended group.

Call Groups and radio scanning

Some professional radios can scan multiple channels or groups.

This can allow a user to monitor more than one communication group without manually changing the selected group.

For example, a security supervisor might normally communicate on the Security Call Group while also monitoring an Operations group.

Scanning behaviour depends on the radio and its programming.

Call Groups and control rooms

Call Groups are particularly useful where a radio system includes a control room or dispatcher.

A control-room operator may be able to communicate with different teams by selecting their relevant Call Group.

For example, a control room could have separate groups for:

• Security
• Engineering
• Transport
• Facilities
• Management

This allows communications to be directed to the appropriate team without unnecessarily interrupting everyone using the radio system.

Call Groups and emergency communications

Professional digital radio systems may provide dedicated emergency communication functions alongside normal Call Groups.

An emergency transmission can be configured to receive higher priority than ordinary group communications, depending on the radio system.

For example, an organisation could have a normal Security Call Group alongside a dedicated emergency function that alerts the appropriate control room or radio users.

An emergency function should not be confused with an ordinary Call Group, as the two serve different purposes.

Call Groups in large radio systems

Larger organisations may require many different Call Groups.

A company operating across multiple departments, 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. or locations could use a structured group arrangement to keep communications organised.

For example:

Site 1 – Security

Site 1 – Operations

Site 1 – Maintenance

Site 2 – Security

Site 2 – Operations

A suitable radio system can then provide users with access only to the groups relevant to their role.

More advanced systems can also link or temporarily combine groups when wider communication is required.

Call Groups and radio range

A Call Group does not itself increase the physical range of a radio.

The geographical 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. of the communication still depends on the underlying radio system.

A Call Group can operate across direct radio communication, a repeater-based system or a larger networked radio 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., depending on the equipment.

On a networked system, members of the same Call Group may be able to communicate across multiple radio sites.

Call Groups and radio hire

Call Groups are particularly useful when hiring radios for large events, security operations, construction projects and other temporary activities involving multiple teams.

For example, an event could have separate groups for:

• Event management
• Security
• Stewards
• Production
• Medical
• Transport

This allows each team to have its own communications while still allowing selected users or control points to communicate across groups where required.

The available functionality depends on the radio equipment and how the temporary system is programmed.

Call Groups and hybrid radio systems

Some modern communication systems can connect conventional digital radios with other communication devices, including broadbandBroadband is a high-speed data connection used by systems such as PoC radio to carry voice, video and other communications over mobile networks, Wi-Fi or IP networks. or PoC devices.

Where the system supports this functionality, a Call Group can potentially include users operating on different types of compatible communication devices.

This can allow organisations to maintain a common group communication structure even when some users are working outside the coverage area of a conventional radio networkA Network is a connected system of radios, equipment and infrastructure that allows users to communicate across a defined area. Radio networks can range from simple radio-to-radio systems to large multi-site networks..

Choosing Call Groups

The number and structure of Call Groups should reflect how an organisation actually communicates.

Too few groups can result in unnecessary radio traffic, while too many can make the system complicated for users.

When designing a professional radio system, it is useful to consider:

• Which teams need to communicate together
• Which communications need to remain private to a particular team
• Which users need access to multiple groups
• Whether supervisors need to monitor several groups
• Whether a control room needs access to all groups
• Whether emergency communication needs priority
• Whether groups need to be linked between sites

A well-designed Call Group structure can make a busy radio system easier to manage and use.

Call Groups and DCS

DCS can configure professional two-way radio systems with appropriate communication groups according to the requirements of the organisation.

For systems using DMR or other digital radio technologies, this can include programming group IDs, channels, timeslots and scanning arrangements so that users can communicate with the correct teams.

The appropriate Call Group structure depends on the organisation’s size, working environment and communication requirements.

From events and festivals to construction and security, hire two way radios to give your team reliable communication when it matters.