Trunked Radio

Trunked radio (MPT1327) provides advanced voice and data communication.

Over the last decade analogue two way radio has become a victim of its own success, caught between the ever increasing demands of its users and the reduction in the number of frequencies available from Ofcom

The fixed channel allocation utilised in analogue radio makes for simple operation, but is inefficient in the use of radio spectrum. Under the fixed channel system, a user who finds the designated channel occupied is obliged to wait until it becomes free, even if other channels allocated to other groups are not in use. A common pool of channels, allocated to users when required would clearly promote more efficient use of the radio spectrum. The efficient management of a pool of communication channels is a complex computational task but can be best described as follows:

Imagine a bank where every teller had their own queue and you, the customer, could not change queues. You could be standing waiting for service while a neighbouring teller had no customers. This scenario mirrors exactly what happens when placing a call on an analogue radio system, which makes the whole process extremely frustrating. Your channel may often be busy, which means that you cannot speak immediately or potentially your lone worker alarm may not get through, whilst other channels are available and under-utilised. Just as a modern bank provides access to a pool of tellers, trunking radio provides access to a shared pool of radio channels. When you want to place a call a channel is allocated to all participants. Once the call is completed, the channel is returned to the pool for other users. Sharing the channels increases the availability of airtime to all radio users. Developments in microprocessor technology, signaling protocols, digital switches and frequency agile transceivers have enabled Trunked systems to become economically viable.

Trunked systems benefit everyone concerned - the regulatory authorities, network operators and end-users.

The benefits include:

• Fixed Call Costs:
  Low and pre-budgeted operational costs
• Fast Connection
  In a fraction of a second
• Various Call Types Including:
  One-to-one private speech calls
  Group calls (radios can be members of individual or multiple groups)
  Fleet calls (contacts all radios, which is mirrors analogue CBS system)
  Priority calling or emergency calls
• Calls from mobile users to the office or clients:
  Radio-to-telephone (PSTN/PABX)
• Call from the office or customers to mobile users:
  Telephone (PSTN/PABX)-to-radio
• Priority to emergency calls and key staff:
  Call priorities including pre-emptive emergency (These calls always get through)
• Call Queuing:
  In the unlikely event that the network is busy it will automatically queue a radio on a first come first serve basis
• Automatic call back:
  Connecting you to people who have been trying to reach you
• Sending pre-coded messages (e.g. “arrived on site”):
  Status Messages
• Sending short free-form text messages:
  Short data messages
• Sending detailed messages (e.g. repair instructions):
  Non-prescribed data
• User-Friendly Handset Features Including:
  Mobile phone style dialling
  Speed dialling
  Assignment of PABX extension numbers to radios
  Simple dialling schemes for dialling individuals or groups
  Simple data messaging
  Panic Button