GPS
     |
     V
[wireless terminal]
  |
  \-- INVITE sip:911              --> [SIP proxy] --\
      GPos: 42 21 54 N 71 06 18 W                   |
                                                    |
                                      INVITE sip:911
                                      GPos: 42 21 54 N 71 06 18 W      
                                      GL: S3.US.45420.1910
                                                    |
                                                    \---------\
                                                              | 
                                                              | 
[wired terminal]   <---- location info --- [Ethernet switch]  |
     |                                                        | 
     \------  INVITE sip:911  --->  [SIP proxy]  ---> [PSAP]<-/
              GL: S3.US.45420.1910