Left the M3 in an airport parking garage while away on a trip. Checked on it from the app while sitting at gate and got vehicle connection failure. Over a 5 day trip I tried multiple times and on the 2nd day it connected right away. After that could never connect. Landing back in Lauderdale, I was still unable to connect which is a bummer particularly in airport parking lot where it's great to be able to blink lights/honk horn. Since taking delivery last December I've had the occasional connection error, but never persistent like that. I leave it in a garage while I'm at work, and most times am able to connect no problem. Would have wanted a FOB at the airport! Also, I presume that if the alarm went off I would have not received a notification. Any thoughts on the prolonged inability to connect on the trip? Are garages a known problem?
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Vehicle Connection Failure in Parking Garage
- Thread starter PRLM3
- Start date
Doesn’t explain why it worked one time. The other explanation I’ve seen on ours is that the car goes into a deep sleep after awhile when not on wifi. Nothing will wake it up except being ‘touched’: nearby phone and opening a door. Bummer if you want to monitor from away but I think it’s the side effect of trying to balance power conservation and monitoring.
TT97
Active Member
There are many variables that can affect cellular signal. Heavy cellular traffic, weather, cosmic events, etc. In the parking structure, it will typically have poor/no reception but on occasion, the conditions can be just right to overcome the loss of signal from being in the garage.
Given that we're talking about an airport parking garage, my guess is it got through that one time because it was at a moment when no one else was using their cell phone.
Most modern cellular networks are CDMA - several phones share a frequency in every cell, and they use coded matrices to sort out the signals for the different phones. That means that the signal strength is related to the other activity on your frequency, since the rest of it is noise that has to be filtered out - it lowers your signal to noise ratio.
Folks in the industry talk about cells "breathing" because of this - the effective coverage area varies based on user activity. If the car was right at the edge of viable reception because of distance and concrete walls, it can hear the tower when no one else is talking, but not when another phone is - not because of the weak signals from the other phone, but because of the resulting noise in the tower's transmission.
Tesla relies on AT&T service for vehicle connectivity.
Depending on where you parked in the garage, and what other obstacles are in the way between your vehicle's antenna and the nearest cell tower (concrete pillars, floors, other cars, etc), your reception may be marginal, or non-existent. Airports tend to have a lot of concrete structures, and the cell service is notoriously spotty in multi-level parking garages.
All things being equal, you would get the best reception on the roof, and the worst on the basement floor or a multi-level parking garage.
You are correct - without wireless 3G/LTE connectivity, alarm notification would not go anywhere.
Garages are a challenge for cell services.
Particularly, AT&T's cell service
Car wont go into "low-power consumption mode" unless its battery is down to ~0%, so that's not it.
However, if a moving van or a large truck were to park between the location of your Tesla and the nearest cell tower, your reception, which may have been marginal in the first place, would drop to 0. When the obstacles drives away, your remote access to the car would get restored.
AT&T does not use CDMA (GSM and LTE only).
Cell towers have limited capacity, but are usually scaled to the level of simultaneous PDN attaches required for a given venue. This is not to say that AT&T may not have under-invested into cell towers at a given airport location, but that would be unlikely.
Lousy signal propagation and interference from other vehicles in the same garage is far more probable.
HTH,
a
And how exactly do you think LTE works?
Hint: LTE is an evolution of HSPA+ - and High Speed Packet Access is a method of implementing WCDMA on 3G networks...
Saghost - sorry, but you are incorrect and afadeev is 100% right (cell network engineer here). AT&T & TMO use GSM networks, and VZ & Sprint use CDMA. In fact, most of the world uses GSM for 3G, so your statement “most modern networks are CDMA” is also incorrect. And GSM/CDMA 3G networks are completely different from ‘4G’ LTE or VoLTE networks, our current “modern network”.
Not saying anything about the upcoming 5G network, just current network functionality.
regarding the connection problem, I have the same with my car I bought in December as well. I lately had a chat with the mobile service technician who came to replace my tail light. According to him, a reason could be that there is several phones connecting to the car with the same account. Eg you and your wife. The solution is to get a new account for the other phone and erase and replace the apps. I haven't tried yet.
Okay, so what am I missing?
GSM and EDGE are TDMA systems using timeslots to split a frequency.
UTMS/HSPA are both based on W-CDMA using matrix code to share a frequency like CDMA does.
LTE is supposedly a next generation evolution based on all of those and also allowing CDMA2000 and cdmaOne systems to upgrade to it as well. The air interface for it is E-UTRA, which is an advanced evolution of UTMS? Doesn't that make it based on W-CDMA?
There's also mention of something new - OFDMA. I'm not sure I understand that at all - something about choosing slightly different overlapping frequencies for different phones that always have orthogonal carrier waves to keep them separated like the codes do?
I'm definitely over my head in understanding how this new system works, but it seems like it'd still breathe like a CDMA cell - having more transmissions going on on the nominally isolated channels would reduce the effective signal to noise ratio. Is that not the case?
And I’ve had the car become unresponsive many times when it had plenty of power and it wasn’t underground. 3’s go to sleep often.
As I said, the car is unresponsive until someone awakens it with a phone key. What does that have to do with cell signal? At that second I can get to it fine remotely. Please read what I wrote.
As I said, the car is unresponsive until someone awakens it with a phone key. What does that have to do with cell signal? At that second I can get to it fine remotely. Please read what I wrote.
Yeah, ultimately I think this makes the most sense. Particularly since the car was in MIA, and I was in KC literally across the street from an ATT tower with my phone showing 5g and max bars. boaterva is also correct -- it's not that uncommon for me to be unable to connect to the M3.
It does bring up a whole new topic at least for me though (no, it's not cellular technology lol), but parking strategy in garages. It's just a bummer to be away a week and come back to not be able to honk horn / flash lights. May begin seeking out spaces that are at periphery / bordering on open air ...
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