% Parameters

speed = 50; % Mobile speed in m/s

time = 100; % Total simulation time in seconds

dt = 1; % Time step in seconds

num_steps = time / dt;

P0rx = -100; % Minimum received signal strength to avoid drop (dBm)

Phrx = -85;  % Handover threshold (dBm)

margin = 5;  % Handover margin (dB)

d0 = 1; % Reference distance (m)

Pt = 0; % Transmit power in dBm

path_loss_exp = 3.5; % Path loss exponent

sigma_shadow = 6; % Shadowing standard deviation in dB

% Positions of BS A and B

pos_A = 0;

pos_B = 1000;

% Initialize mobile position

pos_mobile = 0;

% Initialize counters

handoffs = 0;

call_drops = 0;

connected_to = 'A';

for t = 1:num_steps

    pos_mobile = pos_mobile + speed * dt;

    

    % Distance to base stations

    d_A = abs(pos_mobile - pos_A);

    d_B = abs(pos_mobile - pos_B);

    

    % Received power with path loss and shadowing

    Prx_A = Pt - 10*path_loss_exp*log10(d_A/d0) + randn * sigma_shadow;

    Prx_B = Pt - 10*path_loss_exp*log10(d_B/d0) + randn * sigma_shadow;

    

    % Call drop check

    if strcmp(connected_to, 'A') && Prx_A < P0rx

        call_drops = call_drops + 1;

        connected_to = 'B'; % Attempt reconnection

        continue;

    elseif strcmp(connected_to, 'B') && Prx_B < P0rx

        call_drops = call_drops + 1;

        connected_to = 'A';

        continue;

    end

    

    % Handover condition

    if strcmp(connected_to, 'A') && Prx_B > Phrx && Prx_A < (Phrx - margin)

        connected_to = 'B';

        handoffs = handoffs + 1;

    elseif strcmp(connected_to, 'B') && Prx_A > Phrx && Prx_B < (Phrx - margin)

        connected_to = 'A';

        handoffs = handoffs + 1;

    end

end

% Output results

fprintf('Number of Handoffs: %d\n', handoffs);

fprintf('Number of Call Drops: %d\n', call_drops);