combo.m

%%=================================================================================================================================================
%%                                      OUTPUT FOR BUFFERED ALOHA WITH 2 ACTIVE NODES (N = 2)
%%=================================================================================================================================================

%%=============Initialisation of variables=========================================================================================================
S_buff_aloha = [];                                    %%  Array to store throughput values (Displayed on the y-axis)
N = 2;                                          %%  To be parameterised for N = 2, 5, 10 and INF
i = 0;
x_vals = [];                                    %%  Values on the x-axis
%%==================================================================================================================================================

%%=============Assuming there are no buffer overflows=======================================================================================

while i <= N                                        %%  dutyCycle needs to be non-negative 
	  G = i;                                    %%  To be parameterised
	  T = G;                                    %%  Both are equal in the case of Buffered ALOHA (T = Transmitted Load & G = Offered Load)
	
%%================(G = T iff there are no buffer overflows and G < Channel Capacity (N))============================================================
	
	  dutyCycle = G/N;
	  P_nb = 1 - dutyCycle;                     %% Probability of not buffered
	  coll1 = P_nb ^ (N - 1);                   %% Collision-1 probability
	  coll2 = exp(-1 * (N - 1) * dutyCycle);    %% Same as the unbuffered case
	
%% fprintf('Iteration = %d \tcollision-1 = %d \tcollision-2 = %d\n', i, coll1, coll2);
%%==================================================================================================================================================

%%===============Throughput calculation and storing in array [S = Ge^(-G)]==========================================================================
	
	  S = G * coll2 * coll1;                    %% Throughput calculation
	  S_buff_aloha = [S_buff_aloha, S];                     %% Appending the values to form a list
      x_vals = [x_vals, i];                     %% Appending the x-values 
      i = i + 0.01;                             %% Incrementing the step-size by a small amount
end

N = 2;                      %% Number of nodes - needs to be parameterised in the future versions; Concretely ==> N = 2, 5, 10 and INF
T = 0.5;                    %% Initial value
dutyCycle = T/N;            %% Setting some value initially
d = 2;                      %% Packet duration
omega = 10;                 %% Packet generation rate 

S_unbuff_T = [];         %% Array to store the throuput info ====> useful info for later processing

%%================ ARRAYS USED FOR PLOTTING G VERSUS T ============================================================================================================

%%=========================================================================================================================================================================
%%                              FOR 2 ACTIVE NODES
%%=========================================================================================================================================================================
T_history_2 = [];
G_history_2 = [];

i = 0;
while i<= N                                            %% G is the Offered Load
    G = i;
    T = G/(1 + G/N);                                    %% G = T / (1 - dutyCycle)
    G_history_2 = [G_history_2, G];                     %% Transmitted Load ======> Useful for plotting the graph between G and T
    T_history_2 = [T_history_2, T];
    collision1 = 1 - power((1 - dutyCycle), N - 1);     %% probability of type-1 collision
    
    P_t = exp(-omega * d);
    collision2 = 1 - power(P_t, N - 1);                 %% Throughoput for unbuffered ALOHA ===> S_unbuff
    
    S_unbuff_tmp = T*(1 - collision1)*(1 - collision2); %% Calculate this value for different values of the parameters and store it in an array
    S_unbuff_T = [S_unbuff_T, S_unbuff_tmp];      %% Appending the newest value, for plotting purposes
    i = i + 0.01;
end

%%=======================Plotting the graphs=========================================================================================================
plot(x_vals, S_buff_aloha, x_vals, S_unbuff_T);                           %% plot(x, y) - syntax
title('Throughput(S) versus Offered Load(G), N = 2');
xlabel('Offered Load(G)');                      %% G = Average number of frames generated by the system during one frame transmission time (Unitless)
ylabel('Throughput(S)');                        %% S = Throughput (Unitless)
i = i + 0.01;
%%===================================================================================================================================================