E60, E61, E63, E64, E87, E90: ULF Functions Sequences
Automatic prioritisation of connected bluetooth mobile phones Up to 4 bluetooth mobile phones can be signed on in sequence to the universal charger and hands-free system.
- If there is more than one bluetooth mobile phone in the reception area of the ULF: The bluetooth mobile phone at the top of the list has priority for building up a connection.
- If there are already 4 bluetooth mobile phones signed on to the ULF, the last bluetooth mobile phone on the list will be deleted the next time a bluetooth mobile phone is signed on. This bluetooth mobile phone must be signed on again before it can be used.
Hands-free mode
- Voice output
In the bluetooth mobile phone, the incoming voice signals are encoded by the bluetooth interface of the bluetooth mobile phone and transmitted by the bluetooth antenna. The signals emitted are received by the bluetooth antenna of the ULF control unit. From the bluetooth antenna, the signals are fed to the bluetooth interface in the ULF control unit. The signals are then digitalized in the ULF control unit. The digital signals are sent through the MOST bus to the audio system. The audio system them emits them as analogue signals through the loudspeakers. Signal path: GSM antenna => Bluetooth mobile phone => ULF bluetooth antenna => ULF => Audio system => Loudspeakers - Voice input
The ULF control unit receives the voice information input via the hands-free microphone. The low-frequency signals from the hands-free microphone are encoded in the ULF control unit in the bluetooth module. The encoded low-frequency signals are transmitted at low output to the bluetooth mobile phone via the connected bluetooth antenna inside the vehicle. The signals received by the aerial of the bluetooth mobile phone are forwarded to the GSM antenna by the bluetooth mobile phone in the snap-in adapter (optionally via a compensator). The signals are transmitted with maximum output by the GSM antenna. Signal path Hands-free microphone => ULF => ULF bluetooth antenna => Bluetooth mobile phone => GSM antenna
To achieve maximum transmission range, the bluetooth mobile phone must be engaged in the snap-in adapter.
Full duplex transmission
The hands-free facility is designed to allow the simultaneous transmission of voice signals in both directions (full duplex). The full duplex transmission makes it possible to speak and hear the other person at the same time. Voice signals are transmitted simultaneously:
- Hands-free microphone => ULF
- ULF => Loudspeakers in vehicle
Echo compensation
If the hands-free microphone and the loudspeakers in the vehicle are active at the same time, there will be feedback. This annoying effect is suppressed by echo compensation. Background noises are dampened.
Transmission of audio data, telephone directory, operating status of bluetooth mobile phone
Audio data (speech), the telephone directory and the current operating status of the bluetooth mobile phone can be transmitted via the bluetooth connection between the mobile phone and the ULF control unit. A band width of approx. 1 MBit/s is available for transmission.
Recharging of battery in bluetooth mobile phone
The charge management circuit in the ULF control unit activates a switch-on signal to start the recharging of the battery in the bluetooth mobile phone. Recharging starts as soon as the bluetooth mobile phone is engaged in the snap-in adapter.