service 6 code indicating whether device has been assigned sid and min using symmetric encryption 7 if sid and min have been assigned sid using symmetric encryption 8 if sid and min have been assigned min using symmetric encryption 9 if sid and min have not been assigned sid using symmetric encryption 10 if sid and min have not been assigned min using symmetric encryption when the initialization call has been successfully completed the service 12 will call the device 11 and issue each legal instruction and data request defined below to test the initialization and will instruct the device 11 to call the primary and secondary phone numbers if the instruction and data requests are correctly received by the device 11 if the data transmitted by the device 11 is correctly received by the service 12 and if the primary and secondary phone numbers are successfully called by the device 11 within ten 10 minutes then the device 11 is initialized otherwise the client is notified that initialization failed the physical communication channel layer 13 is the cellular telephone network and the telephone network between the cellular telephone service provider and the locator services physical location the link layer 15 is an onboard modem using a standard low level modulation protocol such as v 34 v 32bis v 32 v 22bis or v 22 for calls initiated by the service 12 the encryption encoding layer 16 will be the symmetric encryption.