1. Wi-Fi Bluetooth Automotive Coexistence Use Cases
Month Year
doc.: IEEE yy/xxxxr0
January 2018
Wi-Fi Bluetooth Automotive Coexistence Use Cases
Date:
Authors:
Notice: This document has been prepared to assist IEEE It is offered as a basis for discussion and is not binding on the contributing individual(s) or organization(s). The material in this document is subject to change in form and content after further study. The contributor(s) reserve(s) the right to add, amend or withdraw material contained herein.
Jim Lansford, Qualcomm
John Doe, Some Company

2. Big Picture – use cases
January 2018
doc.: IEEE /0005r0
For purposes of this discussion, we’ll assume both Wi-Fi and Bluetooth traffic fall into two basic categories:
Wi-Fi
High priority - EDCA access categories AC3 (AC_VO) and AC2 (AC_VI)
Low priority – EDCA access categories AC1 (AC_BE) and AC0 (AC_BK)
AP vs STA vs GO
Bluetooth (Bluetooth 4.0 basline)
Scans for BT/BLE
Synchronous Connection Oriented (SCO and eSCO)
Asynchronous Connectionless (ACL)
Note that A2DP is a special case of an ACL link
BLE operation
Advertising vs data channels
Other issues
Co-located vs non co-located
Collaborative vs non-collaborative
Some use cases may require collaborative techniques, some may not
Submission
Slide 2
Jim Lansford, Qualcomm

3. Use case matrix Issues: Use case/type Wi-Fi High Priority
January 2018
doc.: IEEE /0005r0
Use case/type
Wi-Fi High Priority
Wi-Fi Low Priority
Bluetooth SCO
Case 1: Priority conflict
Case 2: BT Voice vs Wi-Fi data
Bluetooth ACL
Case 3: Wi-Fi multimedia vs BT data
Case 4: Non-priority
Bluetooth LE
Case 5: BLE defers
Case 6: Best effort
Issues:
Wi-Fi could be operating as an AP, STA or GO
Bluetooth could be operating as a master or slave
Performance metrics have not been defined
eSCO has some attributes of SCO and ACL
eSCO offers better voice quality when there are packet errors
Submission
Slide 3
Jim Lansford, Qualcomm

4. Case 1: Priority conflict
January 2018
doc.: IEEE /0005r0
Examples:
Back seat passenger is doing a video conference (like Facetime) over the in-vehicle Wi- Fi at 2.4GHz while the driver is using Bluetooth for a hands-free call.
Bluetooth headsets being used in the vehicle independent of the IVI, but interfering with the in-vehicle Wi-Fi (also impacts Use Case 4)
Issue: Bluetooth voice quality and Miracast QoS could be difficult to maintain when sharing the 2.4GHz band, especially if there is interference from outside the vehicle
Submission
Slide 4
Jim Lansford, Qualcomm

5. Case 2: BT Voice vs Wi-Fi data
January 2018
doc.: IEEE /0005r0
Examples
Driver is using Bluetooth hands-free to make a call while passengers surf the web using the in-vehicle hotspot at 2.4GHz
Issue: Bluetooth voice quality
eSCO will retry a voice packet if there is an error
Submission
Slide 5
Jim Lansford, Qualcomm

6. Case 3: Wi-Fi multimedia vs BT data
January 2018
doc.: IEEE /0005r0
Examples
In-vehicle IVI system is streaming Miracast video to rear screens in the 2.4GHz band while phone uploads address book to head unit
Issue: Wi-Fi Miracast video/audio quality
Submission
Slide 6
Jim Lansford, Qualcomm

7. Case 4: Non-priority January 2018 doc.: IEEE 802.19-18/0005r0 Examples
BLE TPMS sensors send tire pressure information to telematics unit while users in the car surf the web
Special case – A2DP
Phone streams music via Bluetooth A2DP to IVI system while passengers surf the web
Issue: Throughput may be affected - Streaming services that use Best Effort or background priority in Wi-Fi may have buffer depth issues. Buffer depth may also be an issue for A2DP.
Submission
Slide 7
Jim Lansford, Qualcomm

8. Case 5: Wi-Fi multimedia vs BLE data
January 2018
doc.: IEEE /0005r0
Examples
In-vehicle IVI system is streaming Miracast video to rear screens in the 2.4GHz band while BLE TPMS sends tire pressure data
Miracast audio is streaming to rear speakers while BLE is used as A/V control
Issue: Wi-Fi Miracast video/audio quality
Submission
Slide 8
Jim Lansford, Qualcomm

9. Case 6: Wi-Fi best effort vs BLE data
January 2018
doc.: IEEE /0005r0
Examples
User is surfing the web using the in-vehicle hotspot in the 2.4GHz band while BLE TPMS sends tire pressure data
Submission
Slide 9
Jim Lansford, Qualcomm

10. Conclusion
January 2018
doc.: IEEE /0005r0
Use cases will be valuable for to develop a recommended practice
Some use cases may require co-located and collaborative coexistence techniques
Some use cases can be enabled with non co-located, non- collaborative techniques (e.g. adaptive frequency hopping)
Performance metrics and desired goals for performance have not been defined
Submission
Slide 10
Jim Lansford, Qualcomm