What signals does MyBMW App use to connect.
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Help Support BMW i3 Forum:
If you're asking how the app on your phone communicates with your car, it's either a cellular or WiFi Internet link from your phone to a central server, which processes data and sends it back out via internet and finally a cellular link to the vehicle.
JohnWasser
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Your car has either a 3G or a 4G LTE cellular modem under the back seat. Which you have, I think, depends mostly on the build date. My 2017 model (built in October of 2016) has a 4G LTE modem.
Many carriers are shutting down 3G service so if you have a 3G modem you eventually won't be able to contact the car via the app.
Many carriers are shutting down 3G service so if you have a 3G modem you eventually won't be able to contact the car via the app.
The My BMW app uses whatever Internet connection that your smartphone has. If your smartphone is connected to the Internet via WiFi whether at home or at a WiFi hotspot, the My BMW app would use that connection. If your smartphone is connected to the Internet via a cellular data connection, the My BMW app would use that connection.alex29a said:
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Just to give you a baseline of sorts, my last 30 day cycle of MyBMW app use totaled 23 MB of data, and I use it frequently.
That's more than a sneeze, but it's a sliver of what other apps are capable of. With the smallest phone data plans measuring in the gigabytes, My BMW turns into background noise.
The 4G data your car is using is not the WiFi or cellular data your phone is using. Two different things.
That's more than a sneeze, but it's a sliver of what other apps are capable of. With the smallest phone data plans measuring in the gigabytes, My BMW turns into background noise.
The 4G data your car is using is not the WiFi or cellular data your phone is using. Two different things.
BarryM
Member
Just resurrecting an old thread, I’m not concerned about any data I use on my phone but interested in how the car receives the app messages - what device does the car use and who pays/manages that connection?
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The car uses a cellular modem with a SIM card. The car actually has a phone number that you can find if you access your account at BMW on the web. When you send a message from the MyBMW app, it goes to BMW Servers. The BMW Servers then send it to the car. There is no direct connection between the app and the car. BMW pays/manages those servers.
BarryM
Member
Very interesting, thanks for the explanation.
Has anyone ever confirmed that it uses SMS as the underlying messaging system? I've seen it stated many times but I've never been too sure whether that is assumption or fact.
If an i3 were communicating with its servers via SMS, it wouldn't matter whether its telematics module were 3G or 4G. However, an i3 with a 3G telematics module won't pass messages over a 4G data network, so a cellular data connection must be occurring. I suppose it's possible to use SMS message format over a cellular data connection, but what would be the advantage of doing so?
I just sent a SMS message from my phone to our i3 via its SIM telephone number. It hasn't bounced, but maybe that's not meaningful.
turns2stone
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I work in the wireless industry. Sending a SMS to a non-SMS enabled number will just get discarded in the network core. A connected car data connection is purposely set up in the network provisioning to discard any inbound text or calls.
SMS can't be used to start or transfer data via a session transmission like a car would need.
But, if a computer is sending an SMS to another computer, it can send any data it likes as the content? It is, in effect, simply "data transmission", if both ends have a pre-agreed format for the data.
I don't have an axe to grind on this - I don't have any special desire for it to be one way or another. What I see (for example if I send the "flash headlights" command from the app) suggests to me a slow store-and-forward message-based mechanism rather than a real-time data stream - I have never seen a command like that have an effect in less than 10 seconds, which would easily be achievable with the current state of SMS. But in terms of facts (as opposed to assumption) I really don't know.
turns2stone
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There's a critical piece missing in your example: the carrier's network core.
As mentioned, this core is responsible for not only accepting the SMS, but also sending it to a destination. If the destination is not eligible to receive the SMS (regardless of what info it contains), then the entirety of the data is simply discarded in the network core.
In terms of your "flash headlights" example, that's a TCP session that requires the car to acknowledge that request, else it times out/gets dropped. A TCP data packet/session is not something SMS supports.
I'm not sure I understand the point you're making. If BMW design their server so that (to reduce to complete simplicity) it simply sends an SMS to the car with the text "Flash your headlights" in it and the car's TCM is programmed to react to that by flashing its headlights and then respond with an SMS message with the text "OK", why would you need anything more?
As I said before, I don't *want* it to be SMS based, but I don't see any external evidence to suggest that it is more complex than that.
Above all else I wonder why people elsewhere are stating (as if it is a fact) that the entire remote system is based around SMS messages.
[Edit to be clear: I'm not suggesting that an SMS message originates from the app. The SMS interaction would have to be entirely between the BMW servers and the car.]
turns2stone
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Because your app needs acknowledgement that the flash headlights request was received by the destination, and SMS doesn't support that. Plus, there's all kinds of security protocols needed for your flash headlights request, and again, SMS doesn't support anything like that.
This is not an attempt to be snarky, but the closest example of why SMS doesn't work for the kind of data session required is:
My microwave (the SMS) will boil a cup of water if I put it in there for 5 minutes. Why can't the microwave (SMS) melt a penny if I put it in there for 15 minutes?
I'm not familiar with other discussions on the topic, but those people are likely not familiar with how network transmission protocols/network core functionality for SMS, data and IoT (what BMW uses) work. Those are each 3 separate network cores with different capabilities, features, functions for each.
There's no suggestion that the car needs to send an acknowledgement back to you (in the app). The app converses with BMW's servers, not the car.
As already said, BMW's servers can put what they like in the SMS content. If they need more security, they can add security info at the start of the SMS that only the receiving TCM will accept. If you (or in this case BMW) control both ends of an SMS-based "conversation" then you can embed whatever you like in the SMS content - it doesn't have to be human readable.
As it stands, I've not seen any technical reason why SMS could not be used. You just need to bear in mind that the app is *not* conversing with the car - its "conversation" is entirely with a process running on one of BMW's servers. The SMS-based "conversation" would be on the other side of that process, and not accessible to the app.
turns2stone
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You are mixing up car/app acknowledgment with data transmission acknowledgment - please Google TCP/IP data transmission. You need this to "do" anything related to a data command. Else, when a single bit gets dropped along the way (common), nothing would ever work right.
That 'conversation' running on BMW's servers requires TCP/IP and whatever-security-protocols-they-have. Again, not something SMS supports.
Think in terms of the entire data path that the command needs to travel... needs to start from a phone, travel over a network, to a BMW server, from a server back over a network to the car's modem. Each step along the way (and there are literally dozens), needs both data integrity and security. Else, it never makes it.
The only way to send a message with the text 'Turn on headlights' and have the car interpret that as something to 'do', would be using some sophisticated AI like Gemini or Apple Intelligence to "scrape" the SMS info, then do something that requires a protocol interface to a vehicle system component. I like your idea
But not even Apple can do this yet ha.Anyways, I think I'm going to bow out of this convo. All of the above comments by @EvanstonI3 and @alohart look accurate to me. Piece all of those together with what I've posted and hopefully it will make sense going forward.
Ok - I'll give you an example. I just went out to my car and "woke it up" by sending a cab heating command to it. Then I sent a "flash headlights" command from the app. It took 26 seconds to react. Does that look like a real-time Internet of Things interaction? It doesn't to me.
Now... perhaps it's simply implemented very very badly. Or perhaps it's based on something really primitive. I guess we'll never know, because as I said earlier, all we have so far is assumption, not facts!
Now... perhaps it's simply implemented very very badly. Or perhaps it's based on something really primitive. I guess we'll never know, because as I said earlier, all we have so far is assumption, not facts!
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