We want to ack within five minutes, and be at a laptop within 30. So long as I'm within mobile signal when the page goes off, it doesn't really matter what I'm

We want to ack within five minutes, and be at a laptop within 30. So long as I'm within mobile signal when the page goes off, it doesn't really matter what I'm doing — an ack is a button press on a push notification. And I can stay within 30 minutes of my laptop and an Internet connection by carrying said laptop and my phone (with "unlimited" data). If the primary (paid) on-call doesn't catch the notification, the secondary (unpaid) will be paged. And so on, down a couple more steps, to a senior manager. There's no expectation that anyone other than the primary would actually be available to ack the alert.