Is your application running on Shell?
To cehck if wifi is availabel have you tried signal events to see the netwrok availability to see if valid IP is available?
Can you also provide details of Software version on device and few details of your applications?
Is the Server and SB1 on the same network? If so, the SB1 does support push messaging, here you could send a push message to the SB1 from the server indicating it's alive.