How to refresh a page when net connection established?

Friends,
I am using some form fields in a page . When I reach that page if Net connectivity lose show
error message. But when connectivity established I could not reuse that page without going backward. How to add a line of code to refresh that page when the condition in app.component.ts met as shown:

connectonchange=this.network.onchange().subscribe(() => {
                  switch (this.network.type) {
                  case '2g':
                    console.log('probably not very fast ...');
                    this.showToast("2G!");
                    break;
                  case 'wifi':
                    console.log('wohoo wifi ...');
                    this.showToast("WIFI");
                    break;
                    case 'none':
                    console.log('No network ...');
                    this.showToast("No Network");
                    //Experimental
                    //alert("ddTS: "+this.global1.navPage);
                    //this.synchronize();
                    break;
                    case '4g':
                    console.log('4G ...');
                    this.showToast("4G");
                    break; 
                    case '3g':
                    console.log('3G ...');
                    this.showToast("3G");
                    break;
                    case 'unknown':
                    console.log('unknown network ...');
                    this.showToast("unknown Network");
                    break;

                    //unknown, ethernet, wifi, 2g, 3g, 4g, cellular, none
                }
              });
 

suppose if check 4G how i refresh that page …

please advise

Thanks
Anes