function result=prr_perlink(sender,receiver,dbname,numofpkt)
%% This script calculate packet reception rate (PRR) between a certain
%% transmitter and receiver, given the database name to be queried and the
%% total amount of packet transmitted on the link
quote='''';
sqlitecmd=['sqlite3 ' dbname ' "select id from _senders where name=' quote 'sensor' int2str(receiver) quote ';"'];
 [temp temp2] = system(sqlitecmd);
 [temp3] = strread(temp2,'%d','delimiter','\n');
 sensorID=temp3;
 sqlitecmd=['sqlite3 ' dbname ' "select ReportMsg_NA_r1_numberOfPacketsReceived from sf_sfdata_am80 where oml_sender_id=' int2str(sensorID) ' and ReportMsg_NA_r1_source=' quote int2str(sender) quote '"'];
 [temp temp2] = system(sqlitecmd);%fprintf(fid,[sqlitecmd '\n']);
 [temp3] = strread(temp2,'%d','delimiter','\n');
 result=sum(temp3)/numofpkt;