Java in Simulation Time
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Misc
Pitfalls
- Use Java 1.4 compatibility, BCel cannot handle Java 5.0
- If more than one node use the same NetAddress, the simulation aborts prematurely without any error message.
- All entity classes and related interfaces MUST be public.
- The JUnit test runner is always restarted. Workaround: Write your own test runner using the pattern "setup - test - teardown".
Interesting Things
computeAvgConnectivity
Collisions
- RadioNoiseIndep and RadioSimpleStochastic both do not implement packet collisions on radio level:
RadioNoiseIndep.receive(): case Constants.RADIO_MODE_RECEIVING: if(Main.ASSERT) Util.assertion(signals>0); if(power_mW >= radioInfo.shared.threshold_mW && power_mW > signalPower_mW*thresholdSNR) { lockSignal(msg, power_mW, duration); } break;
- RadioNoiseAdditive implements additive superposition of radio signals and packet collisions. A signal is received only if it is stronger than thresholdSNR multiplied with the sum of the power of all other signals. Otherwise all signals are scrambled.
RadioNoiseAdditive.receive(): case Constants.RADIO_MODE_RECEIVING: if(power_mW > signalPower_mW && power_mW >= totalPower_mW*thresholdSNR) { lockSignal(msg, power_mW, duration); setMode(Constants.RADIO_MODE_RECEIVING); } else if(type == SNR && signalPower_mW < (totalPower_mW-signalPower_mW+power_mW)*thresholdSNR) { unlockSignal(); setMode(Constants.RADIO_MODE_SENSING); } break;
Multi-Channel Support for JiST
Architecture
NetworkIf | MacIf <|-- Mac802_11 <|-- MacMc802_11 | | RadioIf | | | ChannelIf <|------------- Channel | FieldIf
- Channels are realized through an additional channel layer
- Has an active channel within a given set of channels
- Discards packets on other channels
- Delayed channel switching (only possible, when not transmitting)
- TODO Cross-channel interference