Supported Features
The RTL87x2G supports Bluetooth Core Specification version 5.4, enabling customers to create versatile and competitive products across diverse fields such as automotive, industrial, home, and personal applications.
Supported Bluetooth Technology Features
The key features include BIS and CIS for the emerging LE audio market, AoA and AoD technologies for direction finding applications, LE Advertising Extensions, and support for LE 1M PHY, LE 2M PHY, LE Coded PHY. Privacy-related features are also incorporated to ensure user security.
The primary supported features and their overview are detailed as shown below:
Privacy
Privacy feature reduces the ability to track a LE device over a period of time by changing the Bluetooth Device Address on a frequent basis. The frequently changed Bluetooth Device Address is called RPA, and the essential key to generate and resolve RPA is called IRK, which is exchanged during the bonding procedure.
LE Data Packet Length Extension
Previously, the largest payload of the Data Physical Channel PDU was 27 octets. This feature allows the Controller to transmit Data Physical Channel PDU with payload up to 251 octets in the connected state, which significantly improves throughput. Both Central and Peripheral roles are able to initiate the procedure.
LE 2M PHY
In the past, LE technology utilized 1Mbps as its PHY. LE 2M PHY improves a doubling of the data rate.
LE Coded PHY
LE Coded PHY, commonly referred to as LE Long Range, supports error correction coding, leading to an expanded range of communication distance.
LE Advertising Extensions
LE Advertising Extensions enhances the advertising and discovery mechanism between LE devices, allowing for more complex and flexible advertising data transmission. Some of the major updates are listed below:
PHY Support: The feature allows advertising, scanning, and initiating behaviors on LE 2M PHY and LE Coded PHY.
Increased Advertising Data and Scan Response Data Capacity: Provides a larger advertising data and scan response data capacity, enabling devices to transmit more information.
Extended Advertising Channels: Advertising data can be transmitted not only in primary advertising channels (channel index: 37/38/39) but also in secondary advertising channels (channel index: 0~36). The reduction in interference increases the overall efficiency of data transmission.
Periodic Advertising: The support for periodic advertising enables devices to send advertisements at regular intervals. This feature enhances device discoverability and facilitates synchronized transmissions.
Advertising Set: Support multiple advertising configurations to be active.
LE Channel Selection Algorithm #2
Compared to channel selection algorithm #1, algorithm #2 improves the ability to avoid interference.
Algorithm #2 not only supports data channels but also encompasses advertising channels for periodic advertising, as well as isochronous channels for BIS and CIS.
AoA and AoD
AoA and AoD features enable precise location-based services and enhanced directionality in communication such as indoor positioning, asset tracking, and other location-aware scenarios.
AoA allows an LE device make its direction available to a peer device by transmitting direction finding enabled packets using a single antenna. The peer device estimates the angle of arrival by using different elements of the antenna array.
AoD allows an LE device consisting of an antenna array make its angle of departure detectable by transmitting direction finding enabled packets, switching antennae during transmission. The peer device estimates the angle of departure by using a single antenna.
Periodic Advertising Sync Transfer
This feature facilitates the transmission of synchronized periodic advertising timing details from a less-constrained device to another device, such as a wearable device with limited power consumption. The less-constrained device executes the synchronization process and subsequently conveys the acquired synchronization details to another device through a LE link connection. This streamlined process results in lower power consumption and reduced bandwidth usage for the constrained device, optimizing its operational efficiency.
LE Power Control and Path Loss Monitoring
The feature enhances power management and connection reliability between devices. LE Power Control adjusts transmission power dynamically for energy efficiency, which is useful in scenarios with varying distances between devices. Path Loss Monitoring continuously measures signal strength to evaluate connection quality, enabling adaptive communication for improved reliability.
LE Audio (LE Isochronous Channels)
LE audio introduces new isochronous channels, establishing a framework for enhanced audio streaming capabilities.
Both transport modes are conducive to multi-stream scenarios. BIS achieves unidirectional transmission, this mode supports one-to-many communication topologies, providing a broadcast capability. On the other hand, CIS facilitates bidirectional communication between devices, this mode supports one-to-one communication topologies.
LE Channel Classification
The feature allow a Peripheral role report its channel classification results to the Central role. These results encompass information on channels that experience lesser interference, providing the Central role with valuable insights for more informed channel map selection.
The table below shows supported Bluetooth Core Specification technology features of different Bluetooth Host images provided in RTL87x2G SDK. For more information about Bluetooth Host image, please refer to Bluetooth Host Image.
Version |
Features |
bt_host_0_0 |
bt_host_3_0 |
|---|---|---|---|
Bluetooth 4.0 |
Advertiser |
Y |
Y |
Scanner |
Y |
Y |
|
Initiator |
Y |
Y |
|
Central |
Y |
Y |
|
Peripheral |
Y |
Y |
|
Bluetooth 4.1 |
Low Duty Cycle Directed Advertising |
Y |
Y |
LE L2CAP Connection Oriented Channel |
Y |
Y |
|
LE Scatternet |
Y |
Y |
|
LE Ping |
Y |
Y |
|
Bluetooth 4.2 |
LE Data Packet Length Extension |
Y |
Y |
LE Secure Connections |
Y |
Y |
|
Link Layer Privacy |
Y |
Y |
|
Bluetooth 5.0 |
LE 2M PHY |
Y |
Y |
LE Coded PHY |
Y |
Y |
|
High Duty Cycle Non-Connectable Advertising |
Y |
Y |
|
LE Advertising Extensions |
Y |
Y |
|
LE Periodic Advertising |
Y |
N |
|
LE Channel Selection Algorithm #2 |
Y |
Y |
|
Bluetooth 5.1 |
AOA and AOD |
Y |
N |
Periodic Advertising Sync Transfer |
Y |
N |
|
Bluetooth 5.2 |
LE Isochronous Channels |
Y |
N |
Enhanced Attribute Protocol |
Y |
N |
|
LE Power Control |
Y |
N |
|
Bluetooth 5.3 |
LE Channel Classification |
Y |
N |
LE Supported Profiles
The table below shows supported LE profiles in SDK.
Profiles |
Version |
GATT Server Role |
GATT Client Role |
|---|---|---|---|
BAS: Battery Service |
1.0 |
Y |
Y |
CSCS: Cycling Speed and Cadence Service |
1.0 |
Y |
N |
DIS: Device Information Service |
1.1 |
Y |
N |
GLS: Glucose Service |
1.0 |
Y |
N |
HIDS: Human Interface Device Service |
1.0 |
Y |
N |
HRS: Heart Rate Service |
1.0 |
Y |
N |
HTS: Health Thermometer Service |
1.0 |
Y |
N |
IAS: Immediate Alert Service |
1.0 |
Y |
Y |
IPSP: Internet Protocol Support Profile |
1.0 |
Y |
Y |
LLS: Link Loss Service |
1.0.1 |
Y |
N |
LNS: Location and Navigation Service |
1.0 |
Y |
N |
RSCS: Running Speed and Cadence Service |
1.0 |
Y |
N |
ScPS: Scan Parameters Service |
1.0 |
Y |
N |
TPS: Tx Power Service |
1.0 |
Y |
N |
WSS: Weight Scale Service |
1.0 |
Y |
N |
Supported Bluetooth Mesh Technology Features
Spec Version |
Bluetooth Mesh Technology |
Description |
|---|---|---|
Mesh 1.0 |
Relay |
Receive and retransmit mesh messages over the advertising bearer to enable larger networks |
Proxy |
Receive and retransmit mesh messages between GATT and advertising bearers |
|
Low Power |
Operate within a mesh network at significantly reduced receiver duty cycles only in conjunction with a node supporting the Friend feature |
|
Friend |
Help a node supporting the Low Power feature to operate by storing messages destined for those nodes |
|
Mesh 1.1 |
Enhanced Provisioning Authentication |
Support more algorithms in the provisioning protocol |
Remote Provisioning |
Allows adding unprovisioned devices to a Bluetooth mesh network when the provisioner is beyond immediate radio range of the unprovisioned device |
|
Private Beacons |
Privacy for Secure Mesh Beacons |
|
Directed Forwarding |
Help improve performance of a multi-hop network by selecting only a subset of nodes to relay a message from a source to a destination |
|
Subnet Bridge |
Subnet bridge for mesh network |
|
Binary Large Object Transfer |
Enable the transfer of binary large objects between Bluetooth mesh devices |
|
Device Firmware Update |
Enable a firmware upgrade of the Bluetooth mesh devices |