how can I dynamically simulate an ad hoc network?

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I have to simulate a network with n nodes, each of which periodically wakes up and sends a HELLO message in which it indicates whether packets to be sent to other nodes in the network. For example, node 2 wakes up at t = 1 and has a packet for node 6. In the positive case, the node remains active for another s slot (time intervals), otherwise goes off. In the example, node 2 remains active until t = 5. When the node is active waits for the recipient to send a HELLO message: in the positive case sends a DONT SLEEP packet to the recipient in the next slot and then a DATA packet, otherwise turns off. Considering the example then, node 2 remains active waiting for node 6 is awake (it is expected that node 6 sends a HELLO). When t = 5 node 6 sends a HELLO and node 2 is still active: node 2 should send to node 6 a DONT SLEEP packet and then a DATA packet. Here’s the code (the first part is missing).

for t=0:1:tmax
    hold off;
    figure(1);
      %recipient
      dst = floor(n*rand(1));
      for i=1:1:n
          plot(NODE(i).xd,NODE(i).yd, 'o');
          hold on;
          %node wakes up periodically
          if(mod(t,T) == i-1 && T >= n) 
              %struct NODE updates the status vs. time
              NODE(i).state(1,t+1) = 'T';
              %sender sends a HELLO
              PKT(t+1).type = 'H';
              plot(NODE(i).xd,NODE(i).yd, 'k*');
              PKT(t+1).src = i;
              PKT(t+1).dst = 0; %0 broadcast message
              %checks whether there are packets to queue
              if(dst ~= 0 && dst ~= i)
                  %opt field indicates the recipient of HELLO
                  PKT(t+1).opt = dst;
                  %update the queue of packets to send
                  %NODE(i).send is a column vector; when the node i
                  %has a packet to send increments by 1
                  %the cell relative to the recipient
                  NODE(i).send(dst,1) = NODE(i).send(dst,1) + 1; 
              else
                  PKT(t+1).opt = 0;
              end
              % checks whether there are packets to be sent
              for j=1:1:n
                  if(NODE(i).send(j,1) ~= 0)
                      for k=1:1:s
                          % book s successive slots and remains active
                          %for the duration
                          NODE(i).state(1,t+1+k) = 'A';
                      end
                  end
              end
          else
              %node is not activate periodically; check the status
              if(NODE(i).state(1,t+1) == 'A')
                  for j=1:1:n
                      % the active node receives a HELLO from one 
                      %of the nodes to which it must send data
                      if(PKT(t+1).type == 'H' && PKT(t+1).src ==   NODE(i).send(j,1))
                          %transmit status
                          NODE(i).state(1,t+2) = 'T';
                          %receive status
                          NODE(j).state(1,t+2) = 'R';
                          %DON'T SLEEP
                          PKT(t+2).type = 'S';
                          plot(NODE(i).xd,NODE(i).yd, 'r*');
                          PKT(t+2).src = i;
                          PKT(t+2).dst = j;
                          %opt field in DONT SLEEP packet indicates
                          %the number of packets destined for that node
                          PKT(t+2).opt = NODE(i).send(j,1);
                      end
                  end
              elseif(NODE(i).state(1,t+1) == 'T')
                  for j=1:1:n
                      %the active node receives a DONT SLEEP from
                      %one of the nodes to which it must send data
                      if(PKT(t+1).type == 'S' && PKT(t+1).src == NODE(i).send(j,1))
                          NODE(i).state(1,t+2) = 'T';
                          NODE(j).state(1,t+2) = 'R';
                          %DATA packet
                          PKT(t+2).type = 'D';
                          pkt(t+2).src = i;
                          PKT(t+2).dst = j;
                          % decrease the packet queue
                          NODE(i).send(j,1) = NODE(i).send(j,1) - 1;
                      end
                  end
              end
          end
      end
  end

it doen't work and I think that the problem is this line of code "if(PKT(t+1).type == 'H' && PKT(t+1).src == NODE(i).send(j,1))". Because PKT(6) does not exist until i = 6. Can anyone help me?