namespace ara::rds

The namespace provides functional interfaces for sending and receiving raw binary data streams over network connections as well as for time-critical AVTP audio/video streams AUTOSAR_AP_SWS_RawDataStream §1. Applications establish point-to-point connections via client and server classes or use dedicated producer and consumer classes to transmit typed datagrams. Read operations provide the received raw data in a structured manner in result objects. Faulty states during transmission are signaled via a module-specific error domain and standardized error codes [SWS_RDS_12367].

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Context

Within the AUTOSAR Adaptive Platform, the namespace ara::rds provides functional interfaces for transmitting raw binary data streams (Raw Data Streams) over network connections AUTOSAR_AP_SWS_RawDataStream §1. The architecture serves two complementary communication patterns: generic point-to-point transmission of unstructured byte streams and time-critical streaming of typed datagrams according to the IEEE 1722 standard (Audio Video Transport Protocol, AVTP).

For byte stream transmission, RawDataStreamClient and RawDataStreamServer form the central components. The RawDataStreamClient initiates a network connection and processes subsequent read and write operations, while the RawDataStreamServer accepts and manages incoming connection requests. Results of read operations are encapsulated in instances of class ReadDataResult in order to pass received data blocks to the application logic in a structured manner.

For time-critical audio, video, and control streams, ara::rds defines a typed streaming model: IEEE1722RawDataStreamProducer serves as a source for generating and transmitting IEEE 1722 datagrams, while IEEE1722RawDataStreamConsumer acts as a sink for receiving them. Payloads and protocol headers are mapped via specialized datagram types such as IEEE1722DatagramAAF (audio), IEEE1722DatagramRVF (video), IEEE1722DatagramCRF (clock reference), and control datagrams (IEEE1722Datagram61883_IIDC, IEEE1722DatagramNTSCF, IEEE1722DatagramTSCF, and the base datagram IEEE1722Datagram). Common header fields encapsulate IEEE1722DatagramAVTPDUCommonHeaderFields and IEEE1722DatagramAVTPDUCommonStreamHeaderFields.

Context diagram: Interaction of client/server streaming classes and IEEE 1722 streaming components with the error domain in ara::rds. Sources: [SWS_RDS_11298], [SWS_RDS_11299], [SWS_RDS_12367], AUTOSAR_AP_SWS_RawDataStream §1.

Usage Path

In the regular operational sequence of byte stream communication, a server process first instantiates RawDataStreamServer to wait for incoming connections on the network. A client process creates an instance of RawDataStreamClient and establishes the network connection to the server. As soon as the connection is established, the communication partners execute read or write calls. Each read call returns a ReadDataResult, which provides the read binary data for further processing.

In the AVTP scenario, a data producer instantiates a IEEE1722RawDataStreamProducer and configures the desired protocol and stream headers via IEEE1722DatagramAVTPDUCommonStreamHeaderFields. The payload is packed into domain-specific datagrams such as IEEE1722DatagramAAF or IEEE1722DatagramRVF. Interpretation: The transmission to the IEEE1722RawDataStreamConsumer is likely to typically take place over an AVB/TSN network, whereupon the consumer receives and decodes the typed datagrams. Question Q-3502e4b3d8365e69 (open)

Error Scenarios

Error handling in ara::rds integrates seamlessly into the model of the Adaptive Platform and relies on error domains and error codes AUTOSAR_AP_SWS_RawDataStream §1. The module defines the error domain RdsErrorDomain, whose instance can be retrieved via the function GetRdsErrorDomain() [SWS_RDS_11298].

Concrete error situations, such as transmission aborts or connection conflicts, are mapped via the enumeration RdsErrc [SWS_RDS_12367]. To generate module-specific error objects, the namespace provides the utility function MakeErrorCode(RdsErrc code, ara::core::ErrorDomain::SupportDataType data) [SWS_RDS_11299]. Interpretation: Failed I/O operations of the streaming classes are likely to return a corresponding ara::core::ErrorCode. Question Q-16627290fe526e68 (open) In addition, the specialized type RdsException exists for exception-based execution paths.