/*
** Names: Perry Stewart PS808, Daniel Dover DCD160
** Assignment: Programming Assignment 3-Investigating Backoff Protocols
** Date 11/30/18
** Class: Data Communication Networks
*/
#include <iostream>
#include <fstream>
#include <math.h>
#include <bits/stdc++.h>
using namespace std;
int main() {
//creates and opens linearLatency file to write averages to
ofstream linearLatency;
linearLatency.open("linearLatency.txt");
//loop for number of devices starting at 100 and incriimenting by 100 to 6000
for(int number_of_devices = 100; number_of_devices <= 6000; number_of_devices += 100) {
int avg_latency = 0; //initializes the the average latency variable
//loop to test the backoff 10 times
for(int trial = 0; trial < 10; trial++) {
int devices = number_of_devices; //number of devices per trial that will becrimented
int windows_size = 2; //initializes the window size
int latency = 0; //initializes the latency variable for each trial
//loop for iterating through the backoff until all devices have succeeded
while (devices > 0) {
int Device_Choices[windows_size]; //creates an array to store number of devices selecting a slot
memset(Device_Choices, 0, sizeof(Device_Choices)); //initializes all variables in the array to 0
//generates a random number for each device that has not successfully sent and incriments that array index
for(int i = 0; i < devices; i++){
int random_var = rand()%windows_size; //generates a random number based on the window size
Device_Choices[random_var] = Device_Choices[random_var] + 1; //incriments the slot based upon the random variable selected
}
//loop to check if any devices successfully sent
for (int i = 0; i < windows_size; i++){
//checks if only 1 device is in a given slot
if (Device_Choices[i] == 1){
devices--; //decreases the number of devices to still send
//if no devices are left the latency of the run is the slot of the last device to send plus all other windows
if (devices == 0){
latency += i; //increases the latency
}
}
}
//if devices are still left to send increase the latency by the current windo size
if (devices > 0) {
latency += windows_size; //increases the latency
}
windows_size++; //increases the window size by 1
}
avg_latency += latency; //adds the current trial latency to the average latency variable
}
linearLatency << avg_latency/10 << "\n"; //adds the average latency of 10 trials per number of devices to a file
}
linearLatency.close(); //closes the text file
//creates and opens binaryLatency file to write averages to
ofstream binaryLatency;
binaryLatency.open("binaryLatency.txt");
//loop for number of devices starting at 100 and incriimenting by 100 to 6000
for(int number_of_devices = 100; number_of_devices <= 6000; number_of_devices += 100) {
int avg_latency = 0; //initializes the the average latency variable
//loop to test the backoff 10 times
for(int trial = 0; trial < 10; trial++) {
int devices = number_of_devices; //number of devices per trial that will becrimented
int windows_size = 2; //initializes the window size
int latency = 0; //initializes the latency variable for each trial
//loop for iterating through the backoff until all devices have succeeded
while (devices > 0) {
int Device_Choices[windows_size]; //creates an array to store number of devices selecting a slot
memset(Device_Choices, 0, sizeof(Device_Choices)); //initializes all variables in the array to 0
//generates a random number for each device that has not successfully sent and incriments that array index
for(int i = 0; i < devices; i++){
int random_var = rand()%windows_size; //generates a random number based on the window size
Device_Choices[random_var] = Device_Choices[random_var] + 1; //incriments the slot based upon the random variable selected
}
//loop to check if any devices successfully sent
for (int i = 0; i < windows_size; i++){
//checks if only 1 device is in a given slot
if (Device_Choices[i] == 1){
devices--; //decreases the number of devices to still send
//if no devices are left the latency of the run is the slot of the last device to send plus all other windows
if (devices == 0){
latency += i; //increases the latency
}
}
}
//if devices are still left to send increase the latency by the current windo size
if (devices > 0) {
latency += windows_size; //increases the latency
}
windows_size *= 2; //incriments the window size according to the specifications of binary backoff
}
avg_latency += latency; //adds the current trial latency to the average latency variable
}
binaryLatency << avg_latency/10 << "\n"; //adds the average latency of 10 trials per number of devices to a file
}
binaryLatency.close(); //closes the text file
//creates and opens logLatency file to write averages to
ofstream logLatency;
logLatency.open("logLatency.txt");
//loop for number of devices starting at 100 and incriimenting by 100 to 6000
for(int number_of_devices = 100; number_of_devices <= 6000; number_of_devices += 100) {
int avg_latency = 0; //initializes the the average latency variable
//loop to test the backoff 10 times
for(int trial = 0; trial < 10; trial++) {
int devices = number_of_devices; //number of devices per trial that will becrimented
int windows_size = 2; //initializes the window size
int latency = 0; //initializes the latency variable for each trial
//loop for iterating through the backoff until all devices have succeeded
while (devices > 0) {
int Device_Choices[windows_size]; //creates an array to store number of devices selecting a slot
memset(Device_Choices, 0, sizeof(Device_Choices)); //initializes all variables in the array to 0
//generates a random number for each device that has not successfully sent and incriments that array index
for(int i = 0; i < devices; i++){
int random_var = rand()%windows_size; //generates a random number based on the window size
Device_Choices[random_var] = Device_Choices[random_var] + 1; //incriments the slot based upon the random variable selected
}
//loop to check if any devices successfully sent
for (int i = 0; i < windows_size; i++){
//checks if only 1 device is in a given slot
if (Device_Choices[i] == 1){
devices--; //decreases the number of devices to still send
//if no devices are left the latency of the run is the slot of the last device to send plus all other windows
if (devices == 0){
latency += i; //increases the latency
}
}
}
//if devices are still left to send increase the latency by the current windo size
if (devices > 0) {
latency += windows_size; //increases the latency
}
windows_size = (1 + (1 / log2(windows_size))) * windows_size; //incriments the window size according to the specifications of logarithmic backoff
}
avg_latency += latency; //adds the current trial latency to the average latency variable
}
logLatency << avg_latency/10 << "\n"; //adds the average latency of 10 trials per number of devices to a file
}
logLatency.close(); //closes the text file
return 0;
} Write, Run & Share C++ code online using OneCompiler's C++ online compiler for free. It's one of the robust, feature-rich online compilers for C++ language, running on the latest version 17. Getting started with the OneCompiler's C++ compiler is simple and pretty fast. The editor shows sample boilerplate code when you choose language as C++ and start coding!
OneCompiler's C++ online compiler supports stdin and users can give inputs to programs using the STDIN textbox under the I/O tab. Following is a sample program which takes name as input and print your name with hello.
#include <iostream>
#include <string>
using namespace std;
int main()
{
string name;
cout << "Enter name:";
getline (cin, name);
cout << "Hello " << name;
return 0;
}
C++ is a widely used middle-level programming language.
When ever you want to perform a set of operations based on a condition If-Else is used.
if(conditional-expression) {
//code
}
else {
//code
}
You can also use if-else for nested Ifs and If-Else-If ladder when multiple conditions are to be performed on a single variable.
Switch is an alternative to If-Else-If ladder.
switch(conditional-expression){
case value1:
// code
break; // optional
case value2:
// code
break; // optional
......
default:
code to be executed when all the above cases are not matched;
}
For loop is used to iterate a set of statements based on a condition.
for(Initialization; Condition; Increment/decrement){
//code
}
While is also used to iterate a set of statements based on a condition. Usually while is preferred when number of iterations are not known in advance.
while (condition) {
// code
}
Do-while is also used to iterate a set of statements based on a condition. It is mostly used when you need to execute the statements atleast once.
do {
// code
} while (condition);
Function is a sub-routine which contains set of statements. Usually functions are written when multiple calls are required to same set of statements which increases re-usuability and modularity. Function gets run only when it is called.
return_type function_name(parameters);
function_name (parameters)
return_type function_name(parameters) {
// code
}