feat(cell): model header sizes for messages transmitted by cell

bundle/src/assembly/resources/scenarios/Barnim/cell/cell_config.json

@@ -1,4 +1,11 @@
 {
     "networkConfigurationFile": "network.json",
-    "regionConfigurationFile": "regions.json"
+    "regionConfigurationFile": "regions.json",
+    "headerLengths": {
+        "udpHeader": "8 Bytes",
+        "tcpHeader": "20 Bytes",
+        "ipHeader": "20 Bytes",
+        "cellularHeader": "18 Bytes",
+        "ethernetHeader": "18 Bytes"
+    }
 }

bundle/src/assembly/resources/scenarios/Tiergarten/cell/cell_config.json

@@ -1,4 +1,11 @@
 {
     "networkConfigurationFile": "network.json",
-    "regionConfigurationFile": "regions.json"
+    "regionConfigurationFile": "regions.json",
+    "headerLengths": {
+        "udpHeader": "8 Bytes",
+        "tcpHeader": "20 Bytes",
+        "ipHeader": "20 Bytes",
+        "cellularHeader": "18 Bytes",
+        "ethernetHeader": "18 Bytes"
+    }
 }

fed/mosaic-cell/src/main/java/org/eclipse/mosaic/fed/cell/config/CCell.java

@@ -16,6 +16,10 @@
 package org.eclipse.mosaic.fed.cell.config;
 
 import org.eclipse.mosaic.fed.cell.config.model.TransmissionMode;
+import org.eclipse.mosaic.lib.util.gson.DataFieldAdapter;
+import org.eclipse.mosaic.rti.DATA;
+
+import com.google.gson.annotations.JsonAdapter;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -26,6 +30,12 @@
  */
 public final class CCell {
 
+    /**
+     * Configuration of header sizes added to all messages before
+     * simulating packet transmission.
+     */
+    public final CHeaderLengths headerLengths = new CHeaderLengths();
+
     /**
      * Interval (in seconds) in which the bandwidth is aggregated.
      *
@@ -83,4 +93,44 @@ public static class CBandwidthMeasurement {
          */
         public String applicationClass = "*";
     }
+
+    public static class CHeaderLengths {
+
+        /**
+         * The size of all headers of the ethernet link layer (used only for server nodes).
+         * E.g. Ethernet (6 Bytes) + MAC Header (12 Bytes) = ~ 18 bytes
+         */
+        @JsonAdapter(DataFieldAdapter.Size.class)
+        public long ethernetHeader = 18 * DATA.BYTE;
+
+        /**
+         * The size of all headers of the cellular link layer.<br>
+         * For example, for 5G we estimate ~18 bytes: SDAP(1 Bytes) + PDCP (3 bytes) + RLC (4 bytes) + MAC (10 bytes)
+         */
+        @JsonAdapter(DataFieldAdapter.Size.class)
+        public long cellularHeader = 18 * DATA.BYTE;
+
+        /**
+         * The size of IP header added to all messages.
+         * In the default configuration we assume IPv4 (20 bytes)
+         */
+        @JsonAdapter(DataFieldAdapter.Size.class)
+        public long ipHeader = 20 * DATA.BYTE;
+
+        /**
+         * The size of TCP header added to all messages which use
+         * {@link org.eclipse.mosaic.lib.enums.ProtocolType#TCP}
+         * for transmission.
+         */
+        @JsonAdapter(DataFieldAdapter.Size.class)
+        public long tcpHeader = 20 * DATA.BYTE;
+
+        /**
+         * The size of UDP headers added to all messages which use
+         * {@link org.eclipse.mosaic.lib.enums.ProtocolType#UDP}
+         * for transmission.
+         */
+        @JsonAdapter(DataFieldAdapter.Size.class)
+        public long udpHeader = 8 * DATA.BYTE;
+    }
 }

fed/mosaic-cell/src/main/java/org/eclipse/mosaic/fed/cell/module/streammodules/StreamModulesDebugLogger.java

@@ -60,7 +60,7 @@ static void logChannelCapacityExceeded(Logger log, StreamProcessor.Input input,
         }
 
         long delayInNs = (messageEndTime - input.getMessageStartTime());
-        long msgLenInBit = CapacityUtility.getMessageLength(input.getV2xMessage());
+        long msgLenInBit = CapacityUtility.getMessageLengthWithHeaders(input.getV2xMessage(), input.getNodeId());
         int msgId = input.getV2xMessage().getId();
         final String senderId = input.getV2xMessage().getRouting().getSource().getSourceName();
         if (input.getMode().isUplink()) {
@@ -106,7 +106,7 @@ static void logSuccessfulDelivery(Logger log, StreamProcessor.Input input, Strea
         }
 
         long delayInNs = (result.getMessageEndTime() - input.getMessageStartTime());
-        long msgLenInBit = CapacityUtility.getMessageLength(input.getV2xMessage());
+        long msgLenInBit = CapacityUtility.getMessageLengthWithHeaders(input.getV2xMessage(), input.getNodeId());
         int msgId = input.getV2xMessage().getId();
         if (input.getMode().isUplink()) {
             log.debug(" msg-{} IS deliverable via {} in region \"{}\" "
@@ -157,7 +157,7 @@ static void logUnsuccessfulSending(Logger log, StreamProcessor.Input input, Stre
      */
     private static void logUnsuccessfulSendingWithoutNodeConfig(Logger log, StreamProcessor.Input input, StreamProcessor.Result result) {
         long delayInNs = (result.getMessageEndTime() - input.getMessageStartTime());
-        long msgLenInBit = CapacityUtility.getMessageLength(input.getV2xMessage());
+        long msgLenInBit = CapacityUtility.getMessageLengthWithHeaders(input.getV2xMessage(), input.getNodeId());
         int msgId = input.getV2xMessage().getId();
         if (input.getMode().isUplink()) {
             log.debug(" msg-{} is not sendable via {} in region \"{}\" due to {}"
@@ -188,7 +188,7 @@ private static void logUnsuccessfulSendingWithoutNodeConfig(Logger log, StreamPr
      */
     private static void logUnsuccessfulSendingWithNodeConfig(Logger log, StreamProcessor.Input input, StreamProcessor.Result result) {
         long delayInNs = (result.getMessageEndTime() - input.getMessageStartTime());
-        long msgLenInBit = CapacityUtility.getMessageLength(input.getV2xMessage());
+        long msgLenInBit = CapacityUtility.getMessageLengthWithHeaders(input.getV2xMessage(), input.getNodeId());
         int msgId = input.getV2xMessage().getId();
         if (input.getMode().isUplink()) {
             log.debug(" msg-{} is not sendable via {} in region \"{}\" due to {}"
@@ -225,7 +225,7 @@ static void logUnsuccessfulDelivery(Logger log, StreamProcessor.Input input, Str
         }
 
         long delayInNs = (result.getMessageEndTime() - input.getMessageStartTime());
-        long msgLenInBit = CapacityUtility.getMessageLength(input.getV2xMessage());
+        long msgLenInBit = CapacityUtility.getMessageLengthWithHeaders(input.getV2xMessage(), input.getNodeId());
         int msgId = input.getV2xMessage().getId();
         if (input.getMode().isUplink()) {
             log.debug(" msg-{} IS NOT deliverable via {} in region \"{}\" "

fed/mosaic-cell/src/main/java/org/eclipse/mosaic/fed/cell/module/streammodules/StreamProcessor.java

@@ -196,7 +196,7 @@ private long calculateNeededBandwidthStream(Input input, Result result) {
      * @return Bandwidth for the data packets.
      */
     private long calculateNeededBandwidthPacket(Input input, Result result, long coreDelayInNs, int prPlAttempts) {
-        long messageSize = CapacityUtility.getMessageLength(input.v2xMessage);
+        long messageSize = CapacityUtility.getMessageLengthWithHeaders(input.v2xMessage, input.nodeId);
         long neededBandwidth = prPlAttempts * CapacityUtility.calculateNeededCapacity(messageSize, coreDelayInNs) * DATA.BIT;
 
         // When the bandwidth is sufficient go on and send the packet

fed/mosaic-cell/src/main/java/org/eclipse/mosaic/fed/cell/utility/CapacityUtility.java

@@ -15,8 +15,13 @@
 
 package org.eclipse.mosaic.fed.cell.utility;
 
+import static org.eclipse.mosaic.lib.objects.UnitNameGenerator.isServer;
+import static org.eclipse.mosaic.lib.objects.UnitNameGenerator.isTmc;
+
+import org.eclipse.mosaic.fed.cell.config.CCell;
 import org.eclipse.mosaic.fed.cell.config.model.CNetworkProperties;
 import org.eclipse.mosaic.fed.cell.config.model.TransmissionMode;
+import org.eclipse.mosaic.fed.cell.data.ConfigurationData;
 import org.eclipse.mosaic.lib.objects.communication.CellConfiguration;
 import org.eclipse.mosaic.lib.objects.v2x.MessageStreamRouting;
 import org.eclipse.mosaic.lib.objects.v2x.V2xMessage;
@@ -128,13 +133,35 @@ public static void consumeCapacity(TransmissionMode mode, CNetworkProperties reg
     }
 
     /**
-     * Helper-function to get the effective message length in bits.
+     * Helper-function to get the effective message length in bits. For each message, a header is assumed
+     * to be present according to the protocol type (UDP or TCP) and the link layer (ethernet for servers, or cellular for mobile devices).
+     * According to our definition, we measure / simulate the message data size on the Link Layer (MAC Layer).
      *
      * @param msg V2X message.
      * @return The length of the V2X message.
      */
-    public static long getMessageLength(V2xMessage msg) {
-        return msg.getPayload().getEffectiveLength() * DATA.BYTE;
+    public static long getMessageLengthWithHeaders(V2xMessage msg, String senderOrReceiver) {
+        final CCell.CHeaderLengths headerLengths = ConfigurationData.INSTANCE.getCellConfig().headerLengths;
+        final long linkLayerHeader;
+        if (senderOrReceiver != null && (isServer(senderOrReceiver) || isTmc(senderOrReceiver))) {
+            // let's assume everything is connected via cellular link, except servers and tmcs which are connected with the backbone
+            linkLayerHeader = headerLengths.ethernetHeader;
+        } else {
+            linkLayerHeader = headerLengths.cellularHeader;
+        }
+        switch (msg.getRouting().getDestination().getProtocolType()) {
+            case UDP:
+                return linkLayerHeader
+                        + headerLengths.ipHeader
+                        + headerLengths.udpHeader
+                        + msg.getPayload().getEffectiveLength() * DATA.BYTE;
+            case TCP:
+            default:
+                return linkLayerHeader
+                        + headerLengths.ipHeader
+                        + headerLengths.tcpHeader
+                        + msg.getPayload().getEffectiveLength() * DATA.BYTE;
+        }
     }
 
     /**

fed/mosaic-cell/src/test/java/org/eclipse/mosaic/fed/cell/junit/CellConfigurationRule.java

@@ -89,6 +89,8 @@ protected void before() throws Throwable {
             File cellConfigFile = copyToFile(cellConfigPath, targetFolder);
             cellConfig = ConfigurationReader.importCellConfig(cellConfigFile.getAbsolutePath());
             ConfigurationData.INSTANCE.setCellConfig(cellConfig);
+        } else {
+            ConfigurationData.INSTANCE.setCellConfig(new CCell());
         }
 
         if (regionConfigPath != null) {