A story of push notifications, sleepy battery-saving phones, and a post office that knocks on your door
Before Push Service, eSIM devices had to wake up every so often and ask the server: "Any new mail for me?" This is called polling. Each wake-up costs battery power: like a child running to the mailbox every hour. Most of the time, there's nothing there, but the battery still drains!
Push Service is like installing a magic doorbell on your phone. Instead of running to check the mailbox every hour, the post office rings your doorbell only when there's actually mail. Your phone stays asleep, saving precious battery, and only wakes up when something important arrives!
Here's how Push Service works: the SM-DP+ server (the "Post Office") knows a new profile is ready for you. Instead of waiting for you to check, it sends a push notification: a tiny "ding-dong!" message: directly to your phone's eSIM. Your phone wakes up, sees the alert, and only then connects to download the new profile.
1. Server packages a profile for you. 2. It sends a tiny push alert: like a doorbell ring. 3. Your phone wakes from deep sleep just long enough to see the alert. 4. Your phone connects, downloads the profile through a secure tunnel, and goes back to sleep. The entire journey uses a fraction of the battery that polling would!
Polling wakes up the phone's radio 24 times a day: even when there's no mail. Push Service wakes it up only when there's actually something to deliver. For most devices, that's a handful of times per month instead of hundreds. The result? Massive battery savings, especially important for small IoT devices with tiny batteries!
Push Service is one of the key features borrowed from IoT (SGP.02) and brought into consumer eSIMs with v3.x. It's the same idea behind your phone's app notifications: but for the eSIM chip itself! Before v3.x, consumer eSIMs had no way to receive push notifications at all. Now they can snooze peacefully until needed!
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