         }
         print("did receive wc session msg (ios app side): \(message)")
         replyHandler(["xxx":"xxx"])
-        registerBackgroundVOIPCallback()
     }
     
     func session(_ session: WCSession, didFinish userInfoTransfer: WCSessionUserInfoTransfer, error: Error?) {

    func applicationDidBecomeActive(_ application: UIApplication) {
        // Restart any tasks that were paused (or not yet started) while the application was inactive. If the application was previously in the background, optionally refresh the user interface.
        print("ios app did become active")
        registerBackgroundVOIPCallback()
    }

    func applicationWillTerminate(_ application: UIApplication) {

        }
    }
    
    func startWCSession() {
        if (WCSession.isSupported() && wcSession == nil) {
            wcSession = WCSession.default()
