Topology

Topology is the shape of the communication plan. It provides an understanding of how each device in the communication plan is connected. Some common network shapes are list below and a communications plan, especially for teams that have multiple work locations in a country, or globally, may have more than one topology in the plan.

Networks

Star Topology

Mesh

Radio

Simplex

Simplex is the most common radio topology and is a radio communicating directly with another radio, not does not retransmit the signal.

Duplex

Duplex topology uses a repeater to extend the range of radio communication. Repeaters can be fixed, or mobile, and are commonly positioned in high places to ensure maximum reach. Repeaters receive transmission on a predefined frequency and then re-transmit at a much higher power output on a different frequency. By re-transmitting on a different frequency, duplex communication allows for real-time (or full-duplex) communication because the repeater does not have to wait for the frequency to be clear before transmitting. Half-duplex repeaters (less common) re transmit the message on the same frequency and therefore slow down communication

Public repeaters

Public repeaters are provided by governments or organisations such as amateur radio clubs or volunteer rescue agencies. With the increase in popularity and decrease in cost of cellular radio towers, public radio repeaters are less common than 20-30 years ago.

Private repeaters

Private repeaters are repeater stations that are owned and operated by private or government organisations for private use. Private repeaters require a licence from the agency that governs radio communication spectrums in each country and usually operate on privately licenced or restricted frequencies that consumer radios cannot access without illegal modifications.