Classifications

• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/28—Data switching networks characterised by path configuration, e.g. LAN [Local Area Networks] or WAN [Wide Area Networks]
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L12/00—Data switching networks
  • H04L12/02—Details
  • H04L12/16—Arrangements for providing special services to substations
  • H04L12/18—Arrangements for providing special services to substations for broadcast or conference, e.g. multicast
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/1066—Session management
  • H04L65/1101—Session protocols
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L65/00—Network arrangements, protocols or services for supporting real-time applications in data packet communication
  • H04L65/60—Network streaming of media packets
  • H04L65/61—Network streaming of media packets for supporting one-way streaming services, e.g. Internet radio
  • H04L65/611—Network streaming of media packets for supporting one-way streaming services, e.g. Internet radio for multicast or broadcast
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
  • H04L67/00—Network arrangements or protocols for supporting network services or applications
  • H04L67/50—Network services
  • H04L67/55—Push-based network services
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/20—Servers specifically adapted for the distribution of content, e.g. VOD servers; Operations thereof
  • H04N21/23—Processing of content or additional data; Elementary server operations; Server middleware
  • H04N21/238—Interfacing the downstream path of the transmission network, e.g. adapting the transmission rate of a video stream to network bandwidth; Processing of multiplex streams
  • H04N21/2381—Adapting the multiplex stream to a specific network, e.g. an Internet Protocol [IP] network
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
  • H04N21/434—Disassembling of a multiplex stream, e.g. demultiplexing audio and video streams, extraction of additional data from a video stream; Remultiplexing of multiplex streams; Extraction or processing of SI; Disassembling of packetised elementary stream
  • H04N21/4345—Extraction or processing of SI, e.g. extracting service information from an MPEG stream
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/40—Client devices specifically adapted for the reception of or interaction with content, e.g. set-top-box [STB]; Operations thereof
  • H04N21/43—Processing of content or additional data, e.g. demultiplexing additional data from a digital video stream; Elementary client operations, e.g. monitoring of home network or synchronising decoder's clock; Client middleware
  • H04N21/438—Interfacing the downstream path of the transmission network originating from a server, e.g. retrieving encoded video stream packets from an IP network
  • H04N21/4381—Recovering the multiplex stream from a specific network, e.g. recovering MPEG packets from ATM cells
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N21/00—Selective content distribution, e.g. interactive television or video on demand [VOD]
  • H04N21/60—Network structure or processes for video distribution between server and client or between remote clients; Control signalling between clients, server and network components; Transmission of management data between server and client, e.g. sending from server to client commands for recording incoming content stream; Communication details between server and client 
  • H04N21/63—Control signaling related to video distribution between client, server and network components; Network processes for video distribution between server and clients or between remote clients, e.g. transmitting basic layer and enhancement layers over different transmission paths, setting up a peer-to-peer communication via Internet between remote STB's; Communication protocols; Addressing
  • H04N21/643—Communication protocols
  • H04N21/64322—IP
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/24—Systems for the transmission of television signals using pulse code modulation
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N7/00—Television systems
  • H04N7/24—Systems for the transmission of television signals using pulse code modulation
  • H04N7/52—Systems for transmission of a pulse code modulated video signal with one or more other pulse code modulated signals, e.g. an audio signal or a synchronizing signal

Definitions

• the present invention relates to the transmission of DVB (Digital Video Broadcasting) services, DVB defining a service as "a sequence of programs under the control of an operator which can be broadcast within the framework of programming", on an IP type network. (supporting the IP protocol, Internet Protocol, the specification of which can be found in the RFCs “request for comments” maintained by the IETF “Internet Engineering Task Force” under number 791) and more particularly the discovery by a terminal of the services offered on the network.
• DVB Digital Video Broadcasting
• DVB services offered by a network is standardized within the framework of a satellite, cable or digital terrestrial broadcast type network. This standard is described in the document “Digital Video Broadcasting (DVB); Specification for Service Information (SI) in DVB Systems ”published by ETSI (European Telecomunication Standard Institute) under number ETSI EN 300468.
• This document describes a set of tables containing information on the network, on the frequencies to which the data flow containing the services, on the services offered etc. These tables are multiplexed in the data flows, the terminal being configured with the data necessary to connect to a first flow allowing it to receive these tables and to build, according to their content, a database containing the description of the services offered by the network and the connection data necessary for their reception.
• DVB Internet Protocol Infrastructure
• IPI Internet Protocol Infrastructure
• the solution is oriented towards a separation between the broadcasting of services in the form of transport flows containing a single DVB service on the one hand and the information describing these services, available under the form of XML files (extensible Markup Language) accessible for terminals on request.
• the HTTP protocol Hyper Text Transport Protocol
• This solution seems natural because it takes advantage of the bidirectional nature of the IP connection unlike satellite broadcasting for example. It in fact saves bandwidth by only transmitting signaling information on demand and not permanently in the audio and video channel.
• making information available on an IP-type network via HTTP servers in the form of XML data files is the dominant solution widely adopted on this type of network.
• the object of the invention is therefore to offer a method of transmitting DVB services over an IP type network and more particularly the discovery of the services offered on the network by a terminal.
• This method allows the maximum reuse of the production chain currently deployed of DVB services for satellite or cable in order to broadcast DVB services on an IP type network.
• the invention consists of a method of discovery, by a terminal connected to an IP type network, of DVB services on the IP type network, where the terminal uses a first broadcast IP address and a first port number to receive a transport stream broadcast to this IP address on this port.
• the terminal extracts from said flow the signaling tables including the network information table (NIT).
• NIT network information table
• the network descriptors contained in said network information table (NIT) designating broadcast IP addresses and the associated ports, the terminal connects to at least part of the transport flows broadcast to said IP addresses on said ports. so as to read the associated service description table (SDT).
• SDT service description table
• the terminal uses this information to build a possibly unitary list of services available on the network.
• the first broadcast IP address and the first port number are entered by the user.
• the first broadcast IP address and the first port number are obtained from the network by the terminal.
• the streams contain only one DVB service.
• the list of services is included in the NIT contained in the stream available at the first IP address for broadcasting on the first port.
• the invention also relates to an apparatus having means for connecting to a broadcast IP address via means for connection to an IP network and means for decoding DVB streams broadcast at this broadcast IP address, characterized in that the means decoders of DVB streams have the capacity to analyze an NIT, extracted from the stream, containing network descriptors adapted to the IP network and to connect to each broadcast IP address described in said NIT in order to read a DVB stream there and extract therefrom information on the services offered on the network preferably according to any of the methods according to the preceding claims.
• the invention also relates to a descriptor of a broadcast service for a DVB stream intended to be included in an NIT, characterized in that it contains the broadcast IP address of a stream server and a port number on which said server broadcasts a DVB stream over an IP type network.
• FIG. 1 represents a diagram of the production chain for DVB services in as part of a conventional satellite broadcast.
• FIG. 2 represents the architecture of a DVB data stream within the framework of the invention.
• FIG. 3 represents a diagram of an example of a modified production line according to the invention.
• FIG. 4 represents the hardware architecture of a terminal operating according to an exemplary embodiment of the invention.
• FIG. 5 represents a diagram of the different stages of the method.
• Figure 6 shows the structure of an NIT (Network Information Table) according to the DVB standard.
• NIT Network Information Table
• IP multicast in English
• IP multicast in English
• IGMP Internet Gateway Management Protocol
• a multipoint broadcast server is associated with a multipoint broadcast address. This address has the format of an IP address, in a domain reserved for this use, but does not correspond to the IP address of a machine accessible on the network.
• a terminal wishing to connect to this broadcast will send a request on the network containing this multipoint broadcast IP address. This request will be relayed throughout the network until it reaches the server in charge of this broadcast, which will therefore register the terminal as a client for the broadcast.
• the routers on the path between the server and the terminal will then be able to relay the IP packets constituting the flow to the terminals subscribed to the broadcast.
• An optimization of this protocol allows, by knowing the IP address of the server machine in addition to the IP address for multipoint broadcasting, to optimize the route of the subscription request by routing it directly to the destination server instead to distribute it throughout the network. This optimization is known as SSM (Source Specifies Multicast).
• Connection to the transport stream can also be done using a unipoint broadcasting protocol (IP unicast in English).
• IP unicast in English
• An example of such a protocol is the RTSP protocol (Real Time Streaming Protocol) defined in RFC 2326.
• RTSP protocol Real Time Streaming Protocol
• This protocol being used to control the broadcasting of the stream over IP, it is intended to operate in conjunction with a broadcasting protocol properly said as RTP.
• RTP broadcasting protocol
• the main difference with multipoint broadcasting is that with each client wishing to connect to the stream, the server will initiate point-to-point broadcasting between itself and the client. It is obvious that this solution is more expensive in bandwidth than the solution based on multipoint broadcasting, but it is possible in the context of a restricted network where only a small number of terminals are capable of connecting to a stream.
• Figure 1 describes the general architecture of an MPEG-2 DVB service production chain in the context of satellite broadcasting.
• audio and video content 1 that we need to broadcast.
• This content is encoded according to the MPEG2 standard in an encoder 2 to generate an elementary audio / video stream 5.
• the signaling information 3 is generated, it generally comes from a database. data containing descriptive information on the service that we want to distribute. This information is generated in the form of a signaling stream 6.
• Another module 4 supports the generation of a subtitle stream 7. It is also possible to include a stream of interactive applications 8, including the production chain is not detailed here.
• a set of flows of this type can be mixed by a mixer 11 for sending to a satellite 13 via a transmitting station 12. In this case synchronization of the signaling information is necessary between the different flows in order to include information on the other flows in the descriptive tables of each flow.
• These programs can then be received at the user's home via his dish 14 to be decoded by a decoder and displayed on a television. This chain is now well mastered by operators.
• a first stream 41 contains an SDT (Service Description Table) table 43 which describes the service (s) available in the stream.
• the service 42 contains a PMT (Program Map Table) 46 as well as the elementary streams of the service, video 47, audio 48 or other 49.
• the stream also contains a PAT (Program Allocation Table) 44 pointing inter alia to the NIT 45.
• the NIT gives information on the physical organization of the different transport flows 50, 51, 52 offered by the network. The NIT is organized as shown in Figure 6.
• This structure of the NIT remains adapted to the description of a network on
• IP except that it is necessary to define descriptors specific to the IP network so as to take into account the broadband broadcasting system over IP.
• descriptors suitable for multipoint broadcasting:
• IP_source_address 32 bslbf The "descriptor_tag” field is an identifier corresponding to this new type of descriptor.
• the “descriptorjength” field gives the size of the descriptor.
• the "IP_multicast_address” field is the IP address of the multipoint broadcast of the server on which the stream is available.
• the “Multicast_Port_number” field is the port number on the server where you have to connect to receive the stream.
• the “Muiticast_protocol_mapping” field is a field identifying the coding protocol of the service (s) broadcast at this address, it can be MPEG-2, MPEG-4, MHP or others.
• IP_source_address is the real IP address of the server, which allows efficient routing of the connection request to a multipoint broadcasting server according to the SSM protocol.
• the “descriptor ag” field is an identifier corresponding to this new type of descriptor.
• the “descriptorjength” field gives the size of the descriptor.
• the "IP_unicast_address” field is the unipoint broadcast IP address of the server on which the stream is available.
• the "Unicast_Port_number” field is the port number on the server where you have to connect to receive the stream.
• the "Unicast_protocol_mapping” field is a field identifying the coding protocol of the service (s) broadcast at this address, it can be MPEG-2, MPEG-4, MHP or others. This optional field can be used to filter on the type of content in order to retain only the services that the terminal is able to decode.
• descriptors signal a multipoint or unipoint broadcast server containing a transport stream, usually with a DVB television service.
• a multipoint or unipoint broadcast server containing a transport stream, usually with a DVB television service.
• the terminal can build a list with the IP addresses of multipoint or unipoint broadcasting of all the transport flows of a broadband television broadcasting network over IP.
• a list of service descriptors can optionally be included in the NIT in order to speed up the installation phase of the terminal.
• FIG. 3 represents a diagram of the architecture of the modified production chain according to an exemplary embodiment of the invention.
• the stream thus formed is placed on a stream server 30 enabling it to be broadcast over the IP network. All the flows constituting the operator's network are thus made available to the terminal 33 connected to its IP network 32, which is symbolized in the diagram by their connection behind the router 31. In practice, these flow servers can be made available.
• ADSL access Asymmetric Digital Subscriber One
• ATM Asynchronous Transfer Mode
• FIG. 4 represents the internal architecture of a terminal 60 which has read only memory (ROM 63) allowing it to store programs and data, random access memory (RAM 62) which allows it to load these programs in view of an execution by the processor 61.
• This processor can also use persistent RAM to store information such as the database.
• This terminal is connected to an IP type network by a network interface 64. These components communicate via an internal bus 65.
• the discovery phase of services on a broadband IP network by a terminal takes place as follows.
• the terminal has a broadband connection to an IP network, this connection can be a connection to the Internet using the ADSL technique or by cable.
• This connection can also be made on a private network, such as a corporate network or a home network.
• the terminal has parameters allowing it to make a first connection to a multipoint or unipoint broadcast IP address.
• This broadcast IP address is entered manually in a configuration menu.
• This broadcast IP address can also be assigned to the terminal during the connection phase via protocols such as DHCP (Dynamic Host Control Protocol) or PPP (Point to Point Protocol). But any other method of determining this first IP address is possible.
• This address consists of a multipoint or unipoint broadcast IP address and a corresponding port number.
• a first step 70 the terminal connects to this IP address on the given port and activates, for example via the IGMP protocol, the reception of the transport stream which is available there.
• this transport stream is of the MPEG-2 type encapsulated over IP using the IP / UDP / RTP (User Datagram Protocol, Real Time Protocol) layers, but it can also be a stream of MPEG-4, MHP or other type. .
• the transport stream is extracted from RTP packets.
• This stream contains the PAT, PMT, NIT and SDT tables.
• the tables contained in the stream are exactly the tables as specified in the DVB-SI standard, with the exception of the network descriptors as defined above located in the NIT.
• the terminal extracts the NIT contained in the stream and analyzes it to build the list of broadcast IP addresses and of the associated ports making it possible to receive the streams available on the network.
• a third step 72 the terminal connects successively to at least part of these transport flows available on the network.
• the terminal will extract the service description information contained in the SDT from these flows. Alternatively, this information is read directly via a set of service descriptors included in the NIT. In this case it is not necessary to connect to the different streams available on the network.
• the terminal builds the database containing the list of all the services offered on the network and makes it available to the user via, for example, an electronic program guide.
• the database can, for example, be stored in the terminal's persistent RAM so as to be easily accessible when the terminal is started up without the need to repeat this process.
• the terminal can use the information contained in this database to respond to a request from the user wishing to connect to one of the services offered.
• the terminal finds in the base the IP address and the port number of the flow server broadcasting the desired service, it can therefore connect to the flow in question and retrieve the flow containing the service there to display it.
• the invention allows operators to reuse most of their existing production chain, in particular multiplexers and their equipment for producing signaling information.
• the invention also makes it possible to limit the modifications to be made to the software executed on the decoders. Indeed, only the part managing the IP interface, in place of the satellite or cable reception interface, is new. All the part of flow analysis and signaling information management can be taken from the software used on satellite or cable decoders. Likewise, access control can be used identically.
• the invention therefore makes it possible to adopt the broadcasting of DVB services over a broadband IP network while minimizing the investments and the risks for the operators.

Landscapes

• Engineering & Computer Science (AREA)
• Multimedia (AREA)
• Signal Processing (AREA)
• Computer Networks & Wireless Communication (AREA)
• Business, Economics & Management (AREA)
• General Business, Economics & Management (AREA)
• Data Exchanges In Wide-Area Networks (AREA)
• Two-Way Televisions, Distribution Of Moving Picture Or The Like (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=34307476

Family Applications (1)

Country Status (9)

Families Citing this family (17)

Family Cites Families (14)

• 2003
  • 2003-10-07 FR FR0311706A patent/FR2860674A1/fr active Pending
• 2004
  • 2004-09-27 JP JP2006530449A patent/JP2007507942A/ja active Pending
  • 2004-09-27 MX MXPA06003712A patent/MXPA06003712A/es active IP Right Grant
  • 2004-09-27 EP EP04817161A patent/EP1671466A1/fr not_active Withdrawn
  • 2004-09-27 BR BRPI0415063-5A patent/BRPI0415063A/pt not_active IP Right Cessation
  • 2004-09-27 US US10/574,328 patent/US20070220574A1/en not_active Abandoned
  • 2004-09-27 KR KR1020067006386A patent/KR20060121893A/ko not_active Application Discontinuation
  • 2004-09-27 CN CNA2004800291891A patent/CN1864388A/zh active Pending
  • 2004-09-27 WO PCT/FR2004/050463 patent/WO2005036851A1/fr active Application Filing

Non-Patent Citations (2)

Also Published As

Similar Documents

Legal Events