Description
The Telemetry Subsystem is a Simulation System that manages the connections between Antennae in the Simulation. It is responsible for managing Link Blocks between compatible Antennae, and adding or removing Link Blocks or Antennae when changes occur in the Simulation. These changes could include:
- An Antenna being added to or removed from the Simulation
- An Antenna’s frequency increasing or decreasing
- An Antenna’s bandwidth increasing or decreasing
Example Use Cases
- Managing connections between Transmitters and Receivers: When a new Transmitter is added to the Simulation, the Data Subsystem will create Link Blocks between it and all valid Receivers. If the Transmitter is removed from the Simulation, the Data Subsystem will remove any Link Blocks that were connecting it to the Receivers. If the Transmitter’s Frequency or Bandwidth is modified, the Data Subsystem will assess which of its connections are still valid, and removing any that are not. The system will also create new Link Blocks for any new connections that may now be valid due to a change in frequency or increased bandwidth.
Module Implementation
The Data Subsystem will automatically be created when an Antenna, such as a Receiver or a Transmitter, is added to the scene. As with other Simulation Systems, only one instance of the telemetry subsystem can be created in a Simulation. Adding additional Antennae or calling the above function again will return the same telemetry Subsystem.
Adding an Antenna
When an Antenna is added to the Simulation, the AddAntenna function will be called on the Data Subsystem. This function stores references to the new Antenna in a list of all Antennae in the scene. It will also create a new entry in a Connection Map, indicating which Antennae have valid connections to other Antennae. The key of the new entry will be the newly created Antenna, and the value is a currently empty list of other Antennae.
The empty list is then filled by assessing which existing Antennae are able to establish valid connections with the new Antenna. The criteria for this are:
- Connections can only be made between a Receiver and a Transmitter. Receivers cannot connect to other Receivers, and Transmitters cannot connect to other Transmitters.
- The Connection Type (either Optical or Radio) of the Receiver and the Transmitter must match.
- The difference between the frequency of the two Antennae must be less than or equal to half of the Receiver’s bandwidth:
Where and are the frequencies of the Transmitter and the Receiver respectively, and is the Bandwidth of the Receiver.
A Link Block will be created for each valid connection. This Link Block will be added to the Transmitter and the Receiver, as well as stored in a list on the Data Subsystem of all Link Blocks in the Simulation.
Removing an Antenna
When an antenna is removed from the simulation or otherwise finishes, the RemoveAntenna function will automatically be called on the Data Subsystem. This function will search through all antennae in the simulation and remove all connections that are associated with the removed antenna. The impacted connections will also be removed from the list of connections stored on the remaining antennae, as well as the Data Subsystem.
Modifying an Antenna’s Frequency or Bandwidth
When an Antenna’s frequency or bandwidth is modified, the Telemetry Subsystem will re-evaluate any connections that it has to determine which connections still meet the criteria for a valid connection. This is done by verifying that the difference in frequency between the two antennae is still less than half the Receiver’s bandwidth. Any existing connections that do not meet this criteria will be removed. If the new frequency or bandwidth allows the Antenna to create a new connection with an Antenna that it could not previously connect to, this connection will be added.
Assumptions/Limitations
- The Data Subsystem assumes that all antennae in the scene are either a transmitter or a receiver. It is unable to simulate an antenna that can both transmit and receive. To approximate this, two antennae may be added: one for receiving and one for transmitting.