I don't know what that means because I've never lost a satellite connection, ever, unless I'm in the Lincoln Tunnel for over 30 minutes.
I believe you are confusing two things:
1. Satellite Connection. This is a free wireless service that connects to military satellites in the sky. Has been around for 15+ years. So long as you are not under the ground, you have a GPS connection. As relates to this conversation, the nav in your BMW and the nav in your, say, five year old Garmin Nuvi will work 100% of the time you are not buried under ground because they store all the map data on the device itself. All the device needs is a connection to the satellite network. The satellites are a clock, merely tell the device where you are. The Nuvi or the iDrive have gigs and gigs of data onboard, just need to sync to the GPS satellites in the sky.
2. Data Connection. This is a paid wireless service most commonly used to give you text messages and internet access. Has been around in a semi-decent way for only 5 years. These connections can be very dicey, if you're near MetLife stadium on a football Sunday you can't get any data at all in a one mile radius around the place, if you're in Manhattan and signals are reflected incorrectly off of building surfaces you lose data, if you're in a dead zone in Paramus you lose LTE and only get 2G EDGE, and so on. As relates to this conversation, to use Google maps, Apple maps, or any of the free iPhone apps, you MUST have a data connection because the map data and points of interest are NOT stored on the phone; they are streamed to the iPhone over your 3G or 4G or LTE data connection in realtime as you drive.
Satellite connectivity is the easy part. Very simple set of signals from space, been going on for 15+ years. Cellphone data connectivity is hit-or-miss, costs money. If I bring my 5 year old Nuvi to Florida next week, doesn't matter if AT&T has no coverage in the Everglades; I'm still going to get precise directions. If I leave that home and bring only my iPhone 5 using Google maps for navigation, I'll always have satellite connectivity but if I lose the AT&T data connection I'm screwed, the maps will stop drawing, I'll get lost in the Everglades, have to ask an alligator for directions.
BJ