How Does Wireless Apple CarPlay Work?
While wireless CarPlay has been technically available since iOS 9, it wasn’t until February 2017 that this feature would be released to the public with the newest BMW 5 Series. Recently we got an opportunity to test drive a new 5 Series for a week and got a chance to get hands on with the wireless CarPlay experience.
At its core, Apple CarPlay just mirrors your iPhone display onto your car’s in-dash screen. For this to work it needs to display video for the user interface as well as features like maps for navigation. While Bluetooth works for audio, it cannot handle the bandwidth that video requires. As such a Wi-Fi access point is needed to transfer the data needed for video.
How it Works
Wireless CarPlay has three requirements, a Bluetooth connection, a Wi-Fi access point, and location data. Here’s is a simplified breakdown of the entire process:
1 To initialize the connection the phone uses Bluetooth to send a signal to the head unit requesting to connect.
2. Once the Bluetooth connection is made the phone will request wireless credentials to the Wi-Fi access point.
3. Upon confirmation the head unit will send the wireless credentials to the iPhone, which will cause the phone to search and join the Wi-Fi access point.
4. After the Wi-Fi connection has been established, the Bluetooth signal will disconnect and all audio and video will be transferred over Wi-Fi.
5. And now you’re set, you now can use CarPlay wirelessly.
So on paper wireless CarPlay sounds awesome, after the initial setup you never have to take your phone out again to connect to your car stereo to use CarPlay. But here it comes… it doesn’t always work. In a span of one week the phone would not connect over 25% of the time. Out of 11 times we drove the car; it couldn’t make the initial connection three times. The most likely cause for this is one of the steps not completing during handover from the initial Bluetooth connection to the transfer over to the Wi-Fi access point.
While this might not seem like a big deal, with this BMW you couldn’t just power off the phone or stereo to try and re-connect. You have to shut the car off and re-start to initialize the connection again.
On top of this, because there are many more steps in connecting wirelessly to the head unit compared to just plugging in via USB, it could take to almost one minute to connect to CarPlay wirelessly. Also with the BMW, CarPlay could only be used wirelessly. The USB could be used to charge the phone but could not be used to connect to the head unit to use CarPlay.
In the end when we got the phone to connect wirelessly it worked just at it would with a USB connection. However, whether it being an issue with the BMW head unit or with the Apple CarPlay app itself we can tell there is still some work to be done to make wireless CarPlay viable for everyday users.