Locator function requirement: 

1. Self-checking function: 
Locator will test itself when the device work in the power and self-test results reported to the backstage management system 
2. Real-time monitoring function: 
2.1Locator can send real-time location information according to pre-established time interval to the back office system and the content, includes time, longitude, latitude, direction and status 
2.2. Minimum time interval can be set as 30 seconds 
2.3. Maximum interval time: 30 minutes 
3. E-fence management: 
Background management system can be pre-positioned four electronic fences (rectangular area) in built-in storage, when the moving target leaves the electronic fence, the positioning system will alarm to management back system initiatively 
4. Emergency features: 
If the moving target is in emergency situation, press the locator button on the emergency, the positioning system will automatically dial one of four pre-stored relative contact numbers and emergency information will be sent to the background management system 
5. Voice monitor function: 
If the moving target is in emergency situation, press the locator button on the emergency, the positioning system will open on-site voice monitoring function automatically, which can clearly hear the voice of moving target on-site in the background management system 
6. Telecommunication transmission agreement: 
Communication agreement includes two types of working ways, it transmits in TCP mode 
Locator sends data packets to the backstage management system, referred as upstream 
Back management system send control instructions to locator, referred as downlink