FR2871640A1 - Communication device for use in e.g. audiovisual apparatus, has connection unit with unit for creating plug that stores address corresponding to data flow and direction, at flow creation time, and unit for destructing plug at end of flow - Google Patents

Abstract

The device has a connection unit (22) to establish a data flow between an electronic apparatus (21) and a data network in real time. The unit (22) has a preset plug (26), a creation unit (27) creating a plug (25) that stores an address corresponding to the data flow and data flow direction in the device, at the time of data flow creation, and a destruction unit (28) destructing the plug (25) at the end of data flow.

Description

The present invention relates to communication devices for

  electronic devices connected by a real-time transport protocol to an Internet-type data network, and, more particularly, electronic devices that implement the HAVi standard (Home AudioNideo

  Interoperability; Audio InteroperabilityNideo for the home).

  This is a communication architecture specification between different audiovisual devices used in a family setting.

  This standard is developed by a consortium of manufacturers in the field of consumer electronics. This standard is available on the Consortium's website at www.havi.orq. As of the filing date of this application, the specifications in force bear the version number 1.1 dated May 15, 2001.

  The HAVi architecture is intended to be implemented on consumer electronics equipment as well as computing equipment such as computers.

personal computers.

  This architecture provides a set of services that facilitate the interoperability and development of distributed applications on home networks.

  Initially, this architecture is intended for consumer equipment supporting the IEEE 1394-1995 standard and the IEC 61883 standard associated with it.

  The HAVi architecture is a software architecture that should allow new equipment to easily integrate into a home network and provide services easily. This architecture provides: - a set of software elements as well as protocols and programming interfaces necessary to allow interoperability, - equipment control and abstraction models, - an addressing scheme for the equipment and its components. resources, - an open execution environment supporting visual presentations and equipment commands and providing executable support for third party applications, - communication mechanisms for dynamically extending the environment through direct connection capabilities, and the management of isochronous data flows.

  The types of equipment supporting HAVi are radio receivers, video recorders, cameras, audio and video discs, display screens, amplifiers, modems, etc.

  As mentioned above, the HAVi architecture is based on the IEEE 1394 network and the IEC 61883 standard which complements it. This IEC 61883 standard defines the management of isochronous data flows using the concept of plug control registers (PCR) and the Connection Management Procedures (CMP) required for initialization and the closure of isochronous data transmissions.

  The IEEE 1394 network having limitations, it has been proposed to put the HAVi architecture on a network to the IP (Internet Protocol) standard in order to reuse a very common and well accepted technology. The additional benefit is to make the HAVi architecture independent of the physical structure of the network.

  The applicant has thus proposed a new type of transport protocol having all the necessary HAVi architecture structures.

  However, the IP standard does not know the concept of connection. It is difficult, and perhaps even impossible, to know how many data streams a HAVI device can handle simultaneously. Since a data stream is linked to a socket, this means that the number of outlets for a HAVI device can not be fixed in advance and be well known.

  The object of the invention is therefore to provide sockets within the meaning of the HAVi standard and the IEC 61883 standard that are compatible with the IP standard.

  The object of the present invention is a device for communicating an electronic device connected by a real-time transport protocol to an Internet-type data network and comprising means for connecting at least one data stream between the network and the apparatus, this data stream having an incoming or outgoing direction of the apparatus, and these connection means comprising means for storing at least one address corresponding to the flow and its direction, characterized in that the connection means further comprise means for creating a storage area of the address and the direction of the flow during the creation thereof and, means for destroying said storage area during the closing of the flux.

  According to other characteristics of the invention: for a given flow, the connection means store the address and the direction of the flow in a predetermined storage area or in a storage area created by the creation means, the flows having the same direction have their address and their direction stored in a storage area of the same type, predetermined or created by the creation means, the storage areas created during the creation of a stream are characterized by a value unique to those of the predetermined storage areas, the transport protocol is the RTP standard, - the communication device implements the HAVi protocol. The invention will be better understood on reading the description which will follow, given solely by way of example, and with reference to the appended drawings, in which: FIG. 1 is an operating diagram of the IEC 61883 standard on a IEEE 1394 network, according to the prior art; FIG. 2 is an operating diagram of the IEC 61883 sockets, according to the prior art; FIG. 3 is a flow diagram of the HAVi stream on an IP network, according to the prior art; FIG. 4 is a diagram of the header of a message for creating a source address; FIG. 5 is an overall diagram of an HAVi device 25 connected to an IP network.

  In order to allow an easy study of this description, several definitions extracted from the HAVi specification will now be given.

  A home network is the generic name used to define a communication infrastructure within a home. This name is used as an abstraction of the physical media and protocols associated with them. A home network supports both exchange of equipment management information and exchanges of audio and / or video content.

  A Device Control Module (DCM) is a software element of the HAVi architecture providing an interface for controlling general functions of a device.

  A functional component module (FCM) is a software element of this architecture providing an interface for controlling a specific functional component of a device.

  By functional components is meant an abstraction level which represents a group of functions associated with a piece of equipment. For example, in a digital television, there may be several functional components such as the radio receiver, the decoder, the audio amplifier, etc.

  A connection is a unidirectional data transfer path created by an HAVi architecture component called the Stream Manager. A connection is typically used for a data flow.

  Thus, the concept of input or output plugs, FIG. 1, has been introduced to identify the nodes inside an IEEE 1394 network. An isochronous data stream 1 is related to an I / O tap. output 2. By setting the corresponding parameters in the tap management registers (iPCR for incoming flows, oPCR for outgoing flows), this stream can be connected to an isochronous channel 3 resulting in a real data stream on the IEEE network 1394.

  A catch is static, Figure 2, in the sense that it is physically represented by a register 4 of the PCR 5, the latter having at most 63 registers. This decision thus makes the link between the data stream 1 and the processing application 6.

  In the case of an IP network, FIG. 3, for a given piece of equipment 10, its connection is defined by its IP address X as well as by a gate number Y corresponding to the application or the protocol used. For example, the gate number 80 is well known for use by the HTTP protocol.

  In the case of a HAVi stream, the transport protocol used is the Real-Time Protocol (RTP) standardized by the Internet Engineering Task Force (IETF) under the reference RFC 3550 and other references relating to particular data.

  The RTP protocol has been chosen as particularly well suited to audio and video data streams. Indeed, it possesses possibilities of temporal marking of the packets as well as mechanisms of management to synchronize different flows having temporal characteristics.

  For each RTP session, a gate number is defined.

  Having thus defined a RTP gate number, a socket number 11 is associated with it to indicate the ultimate address of the stream.

  A HAVi stream over an IP network is therefore defined by a triplet (IP address, gate number, socket number) for each end of this stream.

  By way of example, FIG. 4 illustrates the header 15 of a message for creating a source address with this triplet (destination IP address 16, RTP port 17, plug Number 18).

  An electronic device 21 to the HAVi standard, FIG. 5, therefore comprises means 22 for connection to a network 23 of data such as a network with the IP standard.

  The connection means 22 comprise, in addition to the physical devices, the DCM and FCM modules which are loaded, in the HAVi standard, with the relationship between the device and its environment and ensure the local management of the streams under the global control of the Stream Manager. .

  In the remainder of this description, the term DCM is used interchangeably to designate a DCM module or an FCM module, the differences in functionality between the two types of modules being irrelevant for understanding what will follow.

  The connection means 22 thus enable the establishment of a data stream 24 between this apparatus and at least one second apparatus with the HAVi standard.

  This data stream is unidirectional, that is, the data is sent or received on this stream.

  As previously indicated, this stream 24 is therefore defined at the level of the device 21 by a triplet: IP address of the device, the gate number of the HAVi stream and the number of the socket. It also has a sense inbound or outbound with respect to this device. The DCM thus manages the flows intended for the device thanks to this triplet and to the flow direction.

  The electronic device 21 thus has storage means 25, 26, the HAVi socket, allowing it to retain the characteristics of the stream or streams 24 relating thereto.

  However, two streams can also differentiate on the address of the second device.

  Thus, a single tap number is sufficient to handle multiple streams.

  The DCM then comprises means 27 for creating a new socket 25 when a new stream is created. And when this flow is closed, the DCM releases the corresponding plug by means of destruction means. The creation or release of a tap 25 corresponds to a memory management operation, or the storage area, for allocating the characteristic fields of this stream, in particular its tap number and its direction. The number of taps is therefore not fixed a priori but depends only on the maximum size of the storage area. This corresponds to a dynamic management of the catches.

  These dynamic sockets must, however, be differentiated from conventional static sockets.

  Thus, for example, it is no longer possible to answer a question on the number of catches by means of HAVi 1.1.

  The HAVi architecture defines, for example, a DCM function GetPlugCount to know the number of takes. In the case of dynamic sockets, it is necessary to provide a special value, for example ffffh (h for hexadecimal) to indicate that a single dynamic tap is used. Of course, the use of this value ffffh implies that the number of static sockets is at most fffeh in order to be able to differentiate between static and dynamic sockets.

  The function GetPlugCount therefore returns the value ffffh in the case of 25 dynamic sockets and another value, different, actually corresponding to the number of sockets in the case of static sockets.

  It is therefore conceivable that dynamic taps must be differentiated from static taps in their uses.

  In order to ensure coexistence between these two types of plugs, it is therefore necessary to limit the modulus and direction torque to a single type.

  It is thus possible to have a dynamic DCM and static FCM plugs or the reverse, or else dynamic inbound DCM sockets, static outgoing DCM sockets, static inbound FCM sockets, and dynamic outbound FCM sockets.

  And the value of the GetPlugCount function is used to determine the type of sockets used.

  In the described protocol, there is a one-to-one relationship between the plug and the gate.

  However, it is also possible to have several doors in connection with a socket and therefore a HAVi stream. For example, if this stream combines audio and video data, these two types of data can be separated at the RTP level and thus use two different gates.

  The dynamic outlets thus described thus make it possible to use the HAVi architecture on a network with the IP standard.

  The described implementation is based on the HAVi architecture which allows the communication of real time flows between electronic devices. Those skilled in the art can, however, easily adapt this implementation to similar architectures.

Claims (6)

  A communication device of an electronic device (21) connected by a real-time transport protocol to a network (23) of Internet-type data and comprising means (22) for connecting at least one stream (24). ) of data between the network and the apparatus, this data stream (24) having an incoming or outgoing direction of the apparatus, and these connection means (22) having means (25, 26) for storing the less an address corresponding to the flow and its direction, characterized in that the means (22) for connection further comprise means (27) for creating a storage area (25) of the address and the direction of the flow during the creation thereof and means (28) for destroying said storage area (25) at the closing of the stream.   2. Device for communicating an electronic device (21) according to claim 1, characterized in that, for a given flow (24), the connection means (22) store the address and the flow direction in a zone storage (26) predetermined or in a storage area (25) created by the creating means (27).   Device for communicating an electronic device (21) according to claim 2, characterized in that all flows (24) having the same direction have their address and their direction stored in a storage area (25, 26) of same type, predetermined or created by the means of creation (27).   4. Device for communicating an electronic device (21) according to any one of the preceding claims, characterized in that the storage areas (25) created during the creation of a stream are characterized by a unique value different from those of the predetermined storage areas.   5. Device for communicating an electronic device (21) according to any one of the preceding claims, characterized in that the transport protocol (23) is the RTP standard.   6. Device for communicating an electronic device (21) according to any one of the preceding claims, characterized in that it implements the HAVi communication protocol.