Research Article

A Novel Call Admission Control Policy Using Mobility Prediction and Throttle Mechanism for Supporting QoS in Wireless Cellular Networks

Algorithm 1

TSPCAC (time series prediction call admission control).
begin
declare
  time(): system execution time;
  Te: simulation end time;
  BW_L: remaining bandwidth in current time;
  BW_LN: remaining bandwidth in the next time;
  throttle_flagi: alert indictor for a new call admission;
  call_flag: indicator for call request /*judge new call or handoff*/
  thresholdCDP: the predefined threshold for CDP;
  Traffic_c: traffic class;
while(time()< Te)
 begin
  calculate the remaining bandwidth BW_L according to current system utilization;
  if (call_flag == handoff) /*call request is handoff call*/
  begin
   if ((Traffic_c == 2) && (BW_L 4) ) /*traffic of class 2*/
     admit and allocate four units of bandwidths for the handoff call request;
   else if ((Traffic_c ==1) && (BW_L 1) /* traffic of class 1*/
      admit and allocate one unit of bandwidths for the handoff call request;
   else
    reject handoff call request;
   end
else /*call request is new call*/
begin
call the prediction module to obtain system utilization and handoff dropping probability
 in the next time;
calculate the potential remaining bandwidths BW_LN in the next time according to the
 prediction result;
if ((Traffic_c == 2) && (BW_L 4) ) /*traffic of class 2*/
begin
 set the throttle_flagi to 1; /* current cell i is under heavy traffic load*/
   reject new call request;
  end
else if ((Traffic_c ==1) && (BW_L 1) /* traffic of class 1*/
  begin
  set the throttle_flagi to 1;
  reject new call request;
  end
  else if (one of throttle_flagi,j == 1)
/* one of the six adjacent cells j exhausts bandwidth for cell i*/
    reject new call request;
   else if ((BW_LN 4) && (CDP thresholdCDP))
     begin
       admit and allocate the required amount of bandwidth for the handoff call
      request;
       set the throttle_flagi to 0;
    end
    else
      begin
       set the throttle_flagi to 1;
       reject new call request;
      end
     end
  end
end