# BAP Services (LSG) Overview
Logical Service Groups (LSGs) are the functional units within the BAP protocol. Each LSG represents a specific vehicle function or subsystem that can communicate via BAP messages.
## LSG Structure
Each LSG consists of:
- **Unique LSG ID** (PQ, 6-bit value: 0x00-0x3F)
- **Function set** specific to that service
- **Standardized functions** (0x01-0x11) common across LSGs
- **Custom functions** (0x20+) unique to each LSG
## Platform Differences
#### PQ Platform LSG Mapping
- LSG ID included in message header
- Software-based routing
- Limited to 64 LSGs (6-bit addressing)
#### MQB Platform LSG Mapping
- LSG ID embedded in CAN ID
- Hardware filtering support
- Extended addressing capability
- Example: CAN ID 0x1733**0B**10 (LSG 0x0B)
## LSG Categories
### Communication & Entertainment
| LSG ID | Service Name | PQ | MQB | Description |
| ------ | -------------------------------------------------------------------------- | --- | --- | --------------------------------------------- |
| 0x28 | [[lsgs/0x28-telephone\|Telephone]] | Y | | Phone call management, Bluetooth connectivity |
| 0x29 | [[lsgs/0x29-phonebook\|Phonebook]] | Y | | Contact lists, SMS messages, call history |
| 0x2B | [[0x2B (Secondary Display)/Secondary Display Overview\|Secondary Display]] | Y | | Cluster display for phone/media information |
| 0x30 | [[lsgs/0x30-mdi\|MDI]] | Y | | Media Device Interface, iPod/USB control |
### Vehicle Control Systems
| LSG ID | Service Name | Platform | Description |
| ------ | ----------------------------------------------- | -------- | ---------------------------------- |
| 0x01 | [[lsgs/0x01-climate\|Climate Control]] | PQ/MQB | HVAC settings, temperature control |
| 0x08 | [[lsgs/0x08-interior-light\|Interior Lighting]] | PQ/MQB | Ambient lighting control |
| 0x09 | [[lsgs/0x09-exterior-light\|Exterior Lighting]] | MQB | Headlights, turn signals |
| 0x10 | [[lsgs/0x10-seat\|Seat Control]] | MQB | Power seat adjustment, memory |
| 0x13 | [[lsgs/0x13-units\|Units & Settings]] | MQB | Metric/Imperial, language settings |
### Driver Assistance
| LSG ID | Service Name | | Description |
| ------ | ---------------------- | --- | ---------------------------------------- |
| 0x0A | [[lsgs/0x0a-ops\|OPS]] | | Optical Parking System (parking sensors) |
| 0x0B | [[lsgs/0x0b-rvc\|RVC]] | | Rear View Camera control |
| 0x1A | [[lsgs/0x1a-swa\|SWA]] | | Lane Assist (Spurwechselassistent) |
| 0x21 | [[lsgs/0x21-vza\|VZA]] | | Traffic Sign Recognition |
### Convenience Features
| LSG ID | Service Name | | Description |
| ------ | -------------------------------- | --- | ----------------------------- |
| 0x03 | [[lsgs/0x03-webasto\|Webasto]] | | Auxiliary heater control |
| 0x14 | [[lsgs/0x14-homelink\|Homelink]] | | Garage door opener |
| 0x1F | [[lsgs/0x1f-rgs\|RGS]] | | Power rear gate/trunk control |
### System Services
| LSG ID | Service Name | PQ | Description |
| ------ | ----------------------------------- | --- | --------------------------- |
| 0x11 | [[lsgs/0x11-timedate\|Time & Date]] | | System time synchronization |
## Common Functions Across LSGs
All LSGs typically support these standardized functions:
| FCT ID | Function Name | Description |
| ------ | ------------------ | --------------------------------- |
| 0x01 | GetAll | Request all function data |
| 0x02 | BAP_Config | Protocol version and capabilities |
| 0x03 | FunctionList | List of supported functions |
| 0x04 | HeartBeat | Keep-alive signal |
| 0x0F | FSG_OperationState | Module operational status |
| 0x10 | ASG_Capabilities | Display capabilities |
| 0x11 | ASG_Config | Display configuration |
See [[core/Opcodes and Function IDs|Function ID Reference]] for complete details.
## Related Documentation
- [[core/Opcodes and Function IDs|Common Functions & Opcodes]]
- [[core/Header and Multi-frame|Message Structure]]
- [[core/Layer Structure|BAP Stack Architecture]]
- [[platforms/lsg-addressing|Platform-Specific LSG Addressing]]