//======================================================== file = dlc.

//======================================================== file = dlc.c ======//==============================================================================W. Stalllings, Data and Computer Communcations, 6th edition, ==//=-------------------------------------------------------------------------====================//=-------------------------------------------------------------------------==//=-------------------------------------------------------------------------==//=-------------------------------------------------------------------------=====//=-------------------------------------------------------------------------====//===========================================================================//----- Include files -------------------------------------------------------// Needed for printf() and scanf()// Needed for atoi() and atof()// Needed for pow()//----- Defines -------------------------------------------------------------// Copper propagation in meters per second//===== Main program ========================================================void main(void){// Temporary input string// Link distance in meters// Link data rate in bits per second// Frame length in bits// Probability of a bit error// Protocol type (1 = SAW, 2 = SW)// ARQ type for SW (1 = SR, 2 = GBN)// Window size for SW// Probability of a frame error// Stallings "a" parameter// Link utilization as a ratio // Output banner printf("-------------------------------------------- dlc.c ----- n");- n"); printf("-------------------------------------------------------- n"); // Prompt for distance of link in meters printf("Length of link in meters =======================> "); scanf("%s", instring); d = atof(instring); // Prompt for data rate of link in bits per second printf("Data rate of link in bits per second ===========> "); scanf("%s", instring); R = atof(instring); // Prompt for size of frames in bytes (converted to bits for L) printf("Size of frames in bytes ========================> "); scanf("%s", instring); L = 8 * atoi(instring); // Prompt for error rate (BER) printf("Pr[bit error] (0.0 to 1.0) =====================> "); scanf("%s", instring); pr_bit = atof(instring); // Prompt for protocol (SAW or SW) printf("Protocol type (1 = SAW, 2 = SW) ================> "); scanf("%s", instring); protocol_type = atoi(instring); // If SW then prompt for other parameters if (protocol_type == 2) {// Prompt for window sizeprintf("Window size ====================================> ");scanf("%s", instring);N = atoi(instring);// Prompt for error control (GBN or SR)printf("ARQ type (1 = SR, 2 = GBN) =====================> ");scanf("%s", instring);ARQ_type = atoi(instring); } // Compute P (probability of frame error) P = 1 - pow((1 - pr_bit), (double) L); // Compute "a" value a = ((double) R * d) / ((double) V * L); // Compute U for SAW if (protocol_type == 1)U = (1 - P) / (1 + (2 * a)); // Compute U for SW and SR if ((protocol_type == 2) && (ARQ_type == 1))if (N >= ((2 * a) + 1))U = (1 - P);elseU = (N * (1 - P)) / ((2 * a) + 1); // Compute U for SW and GBN if ((protocol_type == 2) && (ARQ_type == 2))if (N >= ((2 * a) + 1))U = (1 - P) / (1 + (2 * a * P));elseU = (N * (1 - P)) / (((2 * a) + 1) * (1 - P + N * P)); // Output results printf("-------------------------------------------------------- n"); printf("- Protocol is "); if (protocol_type == 1)printf("Stop-and-Wait n"); else {printf("Sliding Window with ");if (ARQ_type == 1)printf("Selective Reject ARQ n");elseprintf("Go-Back-N ARQ n"); } printf("- n");= %f n", a);Pr[frame loss] = %f n", P);= %f %% n", 100.0 * U); printf("-------------------------------------------------------- n");}