Test Specification TC21.TS1
Determining minimum periodicity of data transmission for a successful transmission rate over 99%
Test Specification Definition
ID | TC21.TS1 |
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Reference to Test Case | TC21 |
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Title of Test | Determining minimum periodicity of data transmission for a successful transmission rate over 99% |
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Test Rationale | This test allows determining, as a first step, which is the minimum periodicity for which data sent from the real time simulator will result in a packet loss rate less than 1%. This information is needed for the design of the experiment needed to run TS02. |
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Specific Test System
(graphical) | The test system is comprised by the components and their interconnection according to the figure shown above. The real time simulator must send a data profile composed of integer values using “protocol 1” and a value α less than 1. Additionally, the real time simulator must internally register a timestamp for each value sent and a timestamp for when this value is received (if the value is not lost). The communication emulator delay setting must be “0”. This will allow determining the minimum duration a value has to be sent for a 100% successful transmission rate. |
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Target measures | - The roundtrip time for each value sent from the real time simulator to reach the real time simulator, going through the communication devices and the communication emulator.
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Input and output parameters | Controllable input parameters: - Number of numbers that will be used for the data profile (e.g. 30).
- The proportion for which the next sending duration of the next value will be decreased (factor α).
- The specific communication protocol to send the information (Protocol 1 and 2).
- The number of times the data profile will be sent around the system to obtain statistically valid results (e.g. 1000 times)
Uncontrollable parameters: - Time that it takes the data to be received by the real time simulator
Measured parameters: - Values received by the real time simulator
- Roundtrip time of each value received by the real time simulator.
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Test Design | - Choose data profile to be sent around the system.
- Choose the number of times the data profile will be sent around the system.
- Choose communication protocols “Protocol 1” and “Protocol 2”
- Set the delay emulation from the communication emulator to “0”
- Run the experiment and determine for each sent value whether the real time simulator received it.
- If the value was received, determine the roundtrip time by calculating the difference of the timestamps registered by the real time simulator.
- Assess test criteria for each of the values.
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Initial system state | - Devices are on and running
- The real time simulator has sent any value
- The registrations (in the real time simulator) of successful received values and the timestamps of sending/receiving values are empty
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Evolution of system state and test signals | - The successful received values and the timestamps of sending/receiving values are registered in the real time simulator.
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Other parameters | N/A |
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Temporal resolution | - Polling frequency parameters of the protocols being used should be less than the value that has the minimum transmission duration. Polling frequency in the range 1ms-10ms is recommended.
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Source of uncertainty | The delay that can occur within any of the devices used in the system has a stochastic nature. These are therefore sources of uncertainty. |
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Suspension criteria / Stopping criteria | Suspension criteria: Errors in devices Stopping criteria: the experiment concludes when the data profile has been sent a previously defined number of times. |
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