Wireless Siren

Looking to build an outdoor environment friendly product that gives huge alarm/ siren sound on sensing some suspicious activities inside large/ small plantations. Microphone picks up audio signal ( voice or some unusual people movement noise) from some several meters’ distance and activate siren located in a strategic location. You can recommend to have this in multiple locations ( networked) , I mean electronics boxes. You are also recommended to use mobile app through which one activate on sensing threat. I want this solution to use either 2g as net connection would be difficult in remote places. Please share your observation or recommendations. Please allocate this project to any creative mechatronics engineer. If you also activate lights along with siren it will also be good. I am available on call for any clarification