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Use experimentally collected Wi-Fi information in Drop Computing
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@raduciobanu
raduciobanu committed Jul 24, 2018
1 parent 5590f6a commit deccf58
Showing 1 changed file with 115 additions and 34 deletions.
149 changes: 115 additions & 34 deletions src/mobemu/algorithms/DropComputing.java
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Original file line number Diff line number Diff line change
Expand Up @@ -72,11 +72,11 @@ public class DropComputing extends Node {
*/
private static final int BT_SPEED = 3;
/**
* WiFi transfer speed (in MB/s).
* Mobile broadband transfer speed (in MB/s).
*/
private static final int MBB_SPEED = 3;
/**
* Edge transfer speed (in MB/s).
* Edge (Wi-Fi) transfer speed (in MB/s).
*/
private static final int EDGE_SPEED = 10; // caused by Flash write speed
/**
Expand Down Expand Up @@ -190,9 +190,12 @@ protected void onDataExchange(Node encounteredNode, long contactDuration, long c
}

// update battery level
setBatteryOpportunisticExchange(this, dcNode, task.type, sampleTime);
setBatteryOpportunisticExchange(this, dcNode, task.type, sampleTime, currentTime);
} else if ((!completedTasks.contains(task) && condition) || isWiFiAccessPoint) {
// get completed tasks info to disseminate it further
if (completedTasks.size() == 5000000) {
completedTasks.remove(0);
}
completedTasks.add(task);
exchangedData = true;

Expand All @@ -210,17 +213,17 @@ protected void onDataExchange(Node encounteredNode, long contactDuration, long c
}

// update battery level
setBatteryOpportunisticExchange(this, dcNode, task.type, sampleTime);
setBatteryOpportunisticExchange(this, dcNode, task.type, sampleTime, currentTime);
}
}

// compute transfer duration based on task types
long transferDuration = TaskType.getTransferDuration(TaskType.SMALL, dcNode.isWiFiAccessPoint ? 2 : 1)
* exchangedTasksCount[0]
+ TaskType.getTransferDuration(TaskType.MEDIUM, dcNode.isWiFiAccessPoint ? 2 : 1)
* exchangedTasksCount[1]
+ TaskType.getTransferDuration(TaskType.LARGE, dcNode.isWiFiAccessPoint ? 2 : 1)
* exchangedTasksCount[2];
long transferDuration = TaskType.getTransferDuration(TaskType.SMALL, dcNode.isWiFiAccessPoint ? 2 : 1,
dcNode, currentTime) * exchangedTasksCount[0]
+ TaskType.getTransferDuration(TaskType.MEDIUM, dcNode.isWiFiAccessPoint ? 2 : 1, dcNode,
currentTime) * exchangedTasksCount[1]
+ TaskType.getTransferDuration(TaskType.LARGE, dcNode.isWiFiAccessPoint ? 2 : 1, dcNode,
currentTime) * exchangedTasksCount[2];

// clear the current task group if all tasks have finished
if (exchangedData && ownTasks.hasFinished()) {
Expand Down Expand Up @@ -252,13 +255,13 @@ protected void onDataExchange(Node encounteredNode, long contactDuration, long c
// devices, increase battery decrease rate
for (Task task : otherTasks) {
if (!currentTasks.contains(task)) {
setBatteryOpportunisticExchange(this, dcNode, task.type, sampleTime);
setBatteryOpportunisticExchange(this, dcNode, task.type, sampleTime, currentTime);
}
}

for (Task task : dcNode.otherTasks) {
if (!otherNodeTasks.contains(task)) {
setBatteryOpportunisticExchange(dcNode, this, task.type, sampleTime);
setBatteryOpportunisticExchange(dcNode, this, task.type, sampleTime, currentTime);
}
}

Expand Down Expand Up @@ -287,7 +290,7 @@ protected void onDataExchange(Node encounteredNode, long contactDuration, long c
if (task.execute(deviceInfo, sampleTime, id)) {
otherTasks.remove(task);

setBatteryOpportunisticExchange(dcNode, this, task.type, sampleTime);
setBatteryOpportunisticExchange(dcNode, this, task.type, sampleTime, currentTime);

if (task.ownerID == id) {
// if this was a local task, check if the local task group has finished
Expand Down Expand Up @@ -329,16 +332,20 @@ protected void onDataExchange(Node encounteredNode, long contactDuration, long c
* type of task
* @param sampleTime
* sample time of the trace
* @param timestamp
* current trace time
*/
private static void setBatteryOpportunisticExchange(DropComputing first, DropComputing second, TaskType type,
long sampleTime) {
long sampleTime, long timestamp) {
if (!first.isWiFiAccessPoint) {
first.battery.setDecreaseRate(first.battery.getDecreaseRate() + first.deviceInfo
.getTransferBatteryMultiplier(second.isWiFiAccessPoint ? 2 : 1, type, sampleTime));
first.battery
.setDecreaseRate(first.battery.getDecreaseRate() + first.deviceInfo.getTransferBatteryMultiplier(
second.isWiFiAccessPoint ? 2 : 1, type, sampleTime, timestamp, first));
}
if (!second.isWiFiAccessPoint) {
second.battery.setDecreaseRate(second.battery.getDecreaseRate() + second.deviceInfo
.getTransferBatteryMultiplier(first.isWiFiAccessPoint ? 2 : 1, type, sampleTime));
second.battery
.setDecreaseRate(second.battery.getDecreaseRate() + second.deviceInfo.getTransferBatteryMultiplier(
first.isWiFiAccessPoint ? 2 : 1, type, sampleTime, timestamp, second));
}
}

Expand Down Expand Up @@ -786,7 +793,7 @@ private static abstract class DeviceInfo {
*/
protected double mbbBatteryMultiplier = 5.74;
/**
* Battery multiplier when transferring data to the edge device (WiFi).
* Battery multiplier when transferring data to the edge device (Wi-Fi).
*/
protected double edgeBatteryMultiplier = 2.87;
/**
Expand Down Expand Up @@ -818,6 +825,28 @@ public double getTransferBatteryMultiplier(int type, TaskType taskType, long sam
return TaskType.getTransferDuration(taskType, type) * (type == 0 ? mbbBatteryMultiplier
: type == 1 ? bluetoothBatteryMultiplier : edgeBatteryMultiplier) / sampleTime;
}

/**
* Computes the battery multiplier using this device for a task transfer.
*
* @param type
* 0 if the transfer is done using WiFi, 1 if Bluetooth is employed,
* 2 if edge is used
* @param taskType
* type of task
* @param sampleTime
* sample time of the trace
* @param timestamp
* current trace time
* @param node
* current node
* @return the battery multiplier of this device when performing a transfer
*/
public double getTransferBatteryMultiplier(int type, TaskType taskType, long sampleTime, long timestamp,
DropComputing node) {
return TaskType.getTransferDuration(taskType, type, node, timestamp) * (type == 0 ? mbbBatteryMultiplier
: type == 1 ? bluetoothBatteryMultiplier : edgeBatteryMultiplier) / sampleTime;
}
}

/**
Expand Down Expand Up @@ -1276,29 +1305,33 @@ private enum TaskType {
SMALL, MEDIUM, LARGE;

/**
* Gets the scaling factor for a certain type of task.
* Gets the duration (in ms) that it takes for a type of task to be transferred
* through Bluetooth, Wi-Fi, or MBB. We assume tasks of 5 MB.
*
* @param type
* task type
* @return scaling factor for the given task type
* @param exchangeType
* 0 if the task is uploaded using mobile broadband, 1 if Bluetooth
* is employed, 2 if edge is used
* @return duration (in ms) that it takes to upload transfer this type of task
*/
public static int getScalingFactor(TaskType type) {
switch (type) {
default:
case SMALL:
return 1;
case MEDIUM:
return 1000;
case LARGE:
return 10000;
}
public static long getTransferDuration(TaskType type, int exchangeType, DropComputing node, long timestamp) {
double transferSizeMB = 5;
transferSizeMB /= getScalingFactor(type);

double duration = transferSizeMB;
duration /= exchangeType == 0 ? MBB_SPEED
: exchangeType == 1 ? BT_SPEED
: Math.max(EDGE_SPEED, getMaxSpeedBySignalLevel(node.wifiMetrics.getRssi(timestamp)));
// transform to ms
duration *= 1000;

return (long) Math.ceil(duration);
}

/**
* Gets the duration (in ms) that it takes for a type of task to be transferred
* through Bluetooth or WiFi. We assume tasks of 5 MB, a speed of 5 MB/s for
* Cloud download and upload, and 3 MB/s for Bluetooth transfer (which is the
* maximum speed of Bluetooth 3.0).
* towards or from the Cloud. We assume tasks of 5 MB.
*
* @param type
* task type
Expand All @@ -1318,6 +1351,54 @@ public static long getTransferDuration(TaskType type, int exchangeType) {

return (long) Math.ceil(duration);
}

/**
* Computes the maximum Wi-Fi data transfer speed based on signal level (taken
* from https://bit.ly/2uNDikQ).
*
* @param signalLevel
* signal level
* @return data rate
*/
private static int getMaxSpeedBySignalLevel(int signalLevel) {

if (signalLevel < -81) {
return 6;
} else if (signalLevel < -80) {
return 9;
} else if (signalLevel < -78) {
return 12;
} else if (signalLevel < -76) {
return 18;
} else if (signalLevel < -73) {
return 24;
} else if (signalLevel < -69) {
return 36;
} else if (signalLevel < -65) {
return 48;
} else {
return 54;
}
}

/**
* Gets the scaling factor for a certain type of task.
*
* @param type
* task type
* @return scaling factor for the given task type
*/
private static int getScalingFactor(TaskType type) {
switch (type) {
default:
case SMALL:
return 1;
case MEDIUM:
return 1000;
case LARGE:
return 10000;
}
}
}

/**
Expand Down

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