diff --git a/src/python/modes_sbs1.py b/src/python/modes_sbs1.py
index 238b6ee..d5e9112 100644
--- a/src/python/modes_sbs1.py
+++ b/src/python/modes_sbs1.py
@@ -33,6 +33,31 @@ class modes_output_sbs1(modes_parse.modes_parse):
     self._s.listen(1)
     self._s.setblocking(0) #nonblocking
     self._conns = [] #list of active connections
+    self._aircraft_id_map = {} # dictionary of icao24 to aircraft IDs
+    self._aircraft_id_count = 0 # Current Aircraft ID count
+
+  def __del__(self):
+    self._s.close()
+
+  def get_aircraft_id(self, icao24):
+    if icao24 in self._aircraft_id_map:
+      return self._aircraft_id_map[icao24]
+
+    # Adding this new ID to the dictionary
+    self._aircraft_id_count += 1
+    self._aircraft_id_map[icao24] = self._aircraft_id_count
+
+    # Checking to see if we need to clean up in the event that the
+    # dictionary is getting too large.
+    if len(self._aircraft_id_map) > 1e4:
+      minimum = ('', self._aircraft_id_count)
+      for pair in self._aircraft_id_map:
+        if pair[1] < minimum[1]:
+          minimum = pair
+      self._aircraft_id_map.pop(minimum[0])
+
+    # Finally return the new pair
+    return self._aircraft_id_count
 
   def output(self, msg):
     sbs1_msg = self.parse(msg)
@@ -52,9 +77,6 @@ class modes_output_sbs1(modes_parse.modes_parse):
     except socket.error:
       pass
 
-  def __del__(self):
-    self._s.close()
-
   def current_time(self):
     timenow = datetime.now()
     return [timenow.strftime("%Y/%m/%d"), timenow.strftime("%H:%M:%S.000")]
@@ -102,7 +124,8 @@ class modes_output_sbs1(modes_parse.modes_parse):
   def pp0(self, shortdata, parity, ecc):
     [datestr, timestr] = self.current_time()
     [vs, cc, sl, ri, altitude] = self.parse0(shortdata, parity, ecc)
-    retstr = "MSG,7,0,0,0,0,%s,%s,%s,%s,,%s,,,,,,,,,," % (datestr,timestr,datestr,timestr,altitude)
+    aircraft_id = self.get_aircraft_id(ecc)
+    retstr = "MSG,7,0,%i,%X,%i,%s,%s,%s,%s,,%s,,,,,,,,,," % (aircraft_id, ecc, aircraft_id+100, datestr, timestr, datestr, timestr, altitude)
     if vs:
       retstr += "1\n"
     else:
@@ -112,23 +135,27 @@ class modes_output_sbs1(modes_parse.modes_parse):
   def pp4(self, shortdata, parity, ecc):
     [datestr, timestr] = self.current_time()
     [fs, dr, um, altitude] = self.parse4(shortdata, parity, ecc)
-    retstr = "MSG,5,0,0,0,0,%s,%s,%s,%s,,%s,,,,,,," % (datestr,timestr,datestr,timestr,altitude)
+    aircraft_id = self.get_aircraft_id(ecc)
+    retstr = "MSG,5,0,%i,%X,%i,%s,%s,%s,%s,,%s,,,,,,," % (aircraft_id, ecc, aircraft_id+100, datestr, timestr, datestr, timestr, altitude)
     return retstr + self.decode_fs(fs) + "\n"
 
   def pp5(self, shortdata, parity, ecc):
     # I'm not sure what to do with the identiifcation shortdata & 0x1FFF
     [datestr, timestr] = self.current_time()
     [fs, dr, um] = self.parse5(shortdata, parity, ecc)
-    retstr = "MSG,6,0,0,0,0,%s,%s,%s,%s,,,,,,,,," % (datestr,timestr,datestr,timestr)
+    aircraft_id = self.get_aircraft_id(ecc)
+    retstr = "MSG,6,0,%i,%X,%i,%s,%s,%s,%s,,,,,,,,," % (aircraft_id, ecc, aircraft_id+100, datestr, timestr, datestr, timestr)
     return retstr + self.decode_fs(fs) + "\n"
 
   def pp11(self, shortdata, parity, ecc):
     [datestr, timestr] = self.current_time()
     [icao24, interrogator, ca] = self.parse11(shortdata, parity, ecc)
-    return "MSG,8,0,0,%X,0,%s,%s,%s,%s,,,,,,,,,,,,\n" % (icao24,datestr,timestr,datestr,timestr)
+    aircraft_id = self.get_aircraft_id(icao24)
+    return "MSG,8,0,%i,%X,%i,%s,%s,%s,%s,,,,,,,,,,,,\n" % (aircraft_id, icao24, aircraft_id+100, datestr, timestr, datestr, timestr)
 
   def pp17(self, shortdata, longdata, parity, ecc):
     icao24 = shortdata & 0xFFFFFF
+    aircraft_id = self.get_aircraft_id(icao24)
     subtype = (longdata >> 51) & 0x1F
 
     retstr = None
@@ -139,7 +166,7 @@ class modes_output_sbs1(modes_parse.modes_parse):
     if subtype >= 1 and subtype <= 4:
       # Aircraft Identification
       msg = self.parseBDS08(shortdata, longdata, parity, ecc)
-      retstr = "MSG,1,0,0,%X,0,%s,%s,%s,%s,%s,,,,,,,,,,,\n" % (icao24, datestr, timestr, datestr, timestr, msg)
+      retstr = "MSG,1,0,%i,%X,%i,%s,%s,%s,%s,%s,,,,,,,,,,,\n" % (aircraft_id, icao24, aircraft_id+100, datestr, timestr, datestr, timestr, msg)
 
     elif subtype >= 5 and subtype <= 8:
       # Surface position measurement
@@ -147,7 +174,7 @@ class modes_output_sbs1(modes_parse.modes_parse):
       if decoded_lat is None: #no unambiguously valid position available
         retstr = None
       else:
-        retstr = "MSG,2,0,0,%X,0,%s,%s,%s,%s,,%i,,,%.5f,%.5f,,,,0,0,0\n" % (icao24, datestr, timestr, datestr, timestr, altitude, decoded_lat, decoded_lon)
+        retstr = "MSG,2,0,%i,%X,%i,%s,%s,%s,%s,,%i,,,%.5f,%.5f,,,,0,0,0\n" % (aircraft_id, icao24, aircraft_id+100, datestr, timestr, datestr, timestr, altitude, decoded_lat, decoded_lon)
 
     elif subtype >= 9 and subtype <= 18 and subtype != 15:
       # Airborne position measurements
@@ -158,7 +185,7 @@ class modes_output_sbs1(modes_parse.modes_parse):
       if decoded_lat is None: #no unambiguously valid position available
         retstr = None
       else:
-        retstr = "MSG,3,0,0,%X,0,%s,%s,%s,%s,,%i,,,%.5f,%.5f,,,,0,0,0\n" % (icao24, datestr, timestr, datestr, timestr, altitude, decoded_lat, decoded_lon)
+        retstr = "MSG,3,0,%i,%X,%i,%s,%s,%s,%s,,%i,,,%.5f,%.5f,,,,0,0,0\n" % (aircraft_id, icao24, aircraft_id+100, datestr, timestr, datestr, timestr, altitude, decoded_lat, decoded_lon)
 
     elif subtype == 19:
       # Airborne velocity measurements
@@ -166,10 +193,10 @@ class modes_output_sbs1(modes_parse.modes_parse):
       subsubtype = (longdata >> 48) & 0x07
       if subsubtype == 0:
         [velocity, heading, vert_spd] = self.parseBDS09_0(shortdata, longdata, parity, ecc)
-        retstr = "MSG,4,0,0,%X,0,%s,%s,%s,%s,,,%.1f,%.1f,,,%i,,,,,\n" % (icao24, datestr, timestr, datestr, timestr, velocity, heading, vert_spd)
+        retstr = "MSG,4,0,%i,%X,%i,%s,%s,%s,%s,,,%.1f,%.1f,,,%i,,,,,\n" % (aircraft_id, icao24, aircraft_id+100, datestr, timestr, datestr, timestr, velocity, heading, vert_spd)
 
       elif subsubtype == 1:
         [velocity, heading, vert_spd] = self.parseBDS09_1(shortdata, longdata, parity, ecc)
-        retstr = "MSG,4,0,0,%X,0,%s,%s,%s,%s,,,%.1f,%.1f,,,%i,,,,,\n" % (icao24, datestr, timestr, datestr, timestr, velocity, heading, vert_spd)
+        retstr = "MSG,4,0,%i,%X,%i,%s,%s,%s,%s,,,%.1f,%.1f,,,%i,,,,,\n" % (aircraft_id, icao24, aircraft_id+100, datestr, timestr, datestr, timestr, velocity, heading, vert_spd)
 
     return retstr