異構網絡垂直切換算法LTE/WIMAX切換

1.問題描述：

2.部分程式：

%%         the simulation of this program is for heterogeneous          %%
 %%         network in vertical handoff;                                 %%
 %initial the parameters of network
 clear
 clc
 global fc_LTE fc_Wimax LTE_BS_coordinate Wimax_BS_coordinate ...
     Wimax_BS_coordinate LTE_BS_coordinate
 service_type=0;                %the subscriber type of service
                                %0 refers to real time service,on the
                                % contrary,1 refers to nonreal-time service
 MS_coordinate=[100,0];    
 LTE_BS_coordinate=[0,0]; %the coordinate of LTE BS
 Wimax_BS_coordinate=[600,0];   %the coordinate of wimaxE BS
 MS_speed=10;                   %the speed of mobile stationfc_LTE=2000*10^6;              %the frequency of the carrier for LTE
 fc_Wimax=2500*10^6;            %the frequency of the carrier for Wimax
 Net_state=0;                   %0 refers to LTE;1 refers to Wimax
 handoff_drop=1;
 handoff_clock=0;
 count_handoff_number=0;
 Tc=0.5;                      %time of measure interval
 record_time=0;                %record the number of interval time of system
 countinue_run=true;while countinue_run
     
     %#################  measure the receieved signal strength  ############ 
     %if the mobile station is in the LTE network
     if is_in_LTE_coverage(MS_coordinate)
         RSS_LTE=calculate_RSS(MS_coordinate,'LTE');
     else
         RSS_LTE=-inf;
     end
     
     %if the mobile station is in the LTE network
     if is_in_Wimax_coverage(MS_coordinate)
         RSS_Wimax=calculate_RSS(MS_coordinate,'Wimax');
     else
         RSS_Wimax=-inf;
     end
     
     %###############  decide whether to handoff according to RSS  #########
     if Net_state==0&&RSS_LTE<RSS_Wimax
         if handoff_clock>handoff_drop
             if is_network_performance_meet(service_type)==1||(...
                     ~is_in_LTE_coverage(MS_coordinate)&&...
                     is_in_Wimax_coverage(MS_coordinate))
                                              %compare the performance of 
                                              %new network with the past
                                              %network
                 count_handoff_number=count_handoff_number+1;
                 Net_state=1;
                 handoff_clock=0;             %reset the counter
             else
                handoff_clock=0;              %stay in the past network
             end
         else
             handoff_clock=handoff_clock+Tc;
         end
     elseif Net_state==1&&RSS_LTE>RSS_Wimax
         if handoff_clock>handoff_drop
             if is_network_performance_meet(service_type)==0||(...
                     is_in_LTE_coverage(MS_coordinate)&&...
                     ~is_in_Wimax_coverage(MS_coordinate))
                                              %compare the performance of 
                                              %new network with the past
                                              %network
                 count_handoff_number=count_handoff_number+1;
                 Net_state=0;
                 handoff_clock=0;             %reset the counter
             else
                handoff_clock=0;              %stay in the past network
             end
         else
             handoff_clock=handoff_clock+Tc;
         end
     else
         handoff_clock=0;
     end
     
     %#####################  decide whether to continue run ################
     if is_in_LTE_coverage(MS_coordinate)||...
             is_in_Wimax_coverage(MS_coordinate)  
         
         %########################  record the data ########################
         record_time=record_time+1;
         record_RSS_LTE(record_time)=RSS_LTE;
         record_RSS_Wimax(record_time)=RSS_Wimax;
         record_Net_state(record_time)=Net_state; 
         MS_coordinate(1)=MS_coordinate(1)+MS_speed*Tc;
     else
         countinue_run=false;
     end 
 end%######################## plot the simulation results  ####################
 t=[1:record_time]*Tc;
 plot(t,record_RSS_LTE,'--ro','MarkerEdgeColor','g','MarkerFaceColor','y',...
     'MarkerSize',2);
 hold on
 plot(t,record_RSS_Wimax,'-.ks','MarkerEdgeColor','b',...
     'MarkerFaceColor','c','MarkerSize',2);
 hold off
 grid on
 xlabel('time(s)');
 ylabel('RSS(dBm)');
 legend('LTE','Wimax');
 title('the received signal strength about two networks');
 figure
 plot(t,record_Net_state,'--ro','MarkerEdgeColor','g','MarkerFaceColor','y',...
     'MarkerSize',2)
 grid on
 xlabel('time(s)');
 ylabel('mark of network');
 text(0,0,'\leftarrow LTE','FontSize',10)
 text(0,1,'\leftarrow Wimax','FontSize',10)
 title('the state of mobile station in LTE and Wimax network')
 %############################END THE PROGRAM ##############################      

3.仿真結論：