+

WO2006003234A1 - Procede et dispositif pour la distribution de donnees de service - Google Patents

Procede et dispositif pour la distribution de donnees de service Download PDF

Info

Publication number
WO2006003234A1
WO2006003234A1 PCT/FI2004/000414 FI2004000414W WO2006003234A1 WO 2006003234 A1 WO2006003234 A1 WO 2006003234A1 FI 2004000414 W FI2004000414 W FI 2004000414W WO 2006003234 A1 WO2006003234 A1 WO 2006003234A1
Authority
WO
WIPO (PCT)
Prior art keywords
service
service data
predictive
frames
data stream
Prior art date
Application number
PCT/FI2004/000414
Other languages
English (en)
Inventor
Sami Sallinen
Erik Piehl
Original Assignee
Oy Gamecluster Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Oy Gamecluster Ltd filed Critical Oy Gamecluster Ltd
Priority to PCT/FI2004/000414 priority Critical patent/WO2006003234A1/fr
Publication of WO2006003234A1 publication Critical patent/WO2006003234A1/fr

Links

Classifications

    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L69/00—Network arrangements, protocols or services independent of the application payload and not provided for in the other groups of this subclass
    • H04L69/04—Protocols for data compression, e.g. ROHC
    • 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]
    • H04L12/2854—Wide area networks, e.g. public data networks
    • H04L12/2856—Access arrangements, e.g. Internet access
    • H04L12/2869—Operational details of access network equipments
    • H04L12/2878—Access multiplexer, e.g. DSLAM
    • 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]
    • H04L12/2854—Wide area networks, e.g. public data networks
    • H04L12/2856—Access arrangements, e.g. Internet access
    • H04L12/2869—Operational details of access network equipments
    • H04L12/2878—Access multiplexer, e.g. DSLAM
    • H04L12/2879—Access multiplexer, e.g. DSLAM characterised by the network type on the uplink side, i.e. towards the service provider network
    • H04L12/2881—IP/Ethernet DSLAM
    • 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]
    • H04L12/2854—Wide area networks, e.g. public data networks
    • H04L12/2856—Access arrangements, e.g. Internet access
    • H04L12/2869—Operational details of access network equipments
    • H04L12/2878—Access multiplexer, e.g. DSLAM
    • H04L12/2892—Access multiplexer, e.g. DSLAM characterised by the access multiplexer architecture
    • H—ELECTRICITY
    • H04—ELECTRIC COMMUNICATION TECHNIQUE
    • H04L—TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION
    • H04L49/00—Packet switching elements
    • H04L49/90—Buffering arrangements
    • 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
    • H04N21/234—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs
    • H04N21/23406—Processing of video elementary streams, e.g. splicing of video streams or manipulating encoded video stream scene graphs involving management of server-side video buffer
    • 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
    • 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
    • H04L65/60—Network streaming of media packets
    • H04L65/70—Media network packetisation
    • 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
    • H04L65/80—Responding to QoS

Definitions

  • the present invention relates generally to communication systems.
  • the invention concerns digital broadband systems such as Digital Video Broadcasting (DVB) technology and video coding applied therein.
  • DVD Digital Video Broadcasting
  • Digital Video Broadcasting term refers to a number of standards defining digital broadcasting techniques that utilize satellite (DVB-S), cable (DVB-C), or terrestrial (DVB-T) distribution media. Such standards cover source coding, channel coding, conditional access (PayTV and related data scrambling solutions), and various other issues.
  • DVB Project was established by major European public and private sector organizations in the television sector to create a framework for the introduction of MPEG-2 (Moving Picture Experts Group) audio/video compression standard into digital television services. The DVB project has steadily raised its popularity and worldwide adoption thereof is already on hand. Satellite DVB systems are described in reference [1] and MPEG-2 source coding in reference [2]. Cable and terrestrial DVB systems are described in references [3] and [4], respectively.
  • Content provider is an entity or a number of entities providing the clients (-subscribers) with the information flow, notice the elliptical patters for visualizing the flow, to be actually physically transferred by a service provider over a delivery network being transparent to the IP traffic.
  • Tasks of the content provider may include, for example, authentication/authorization services, service portals maintenance, service offering, service discovery mechanisms, metadata services, actual content services etc.
  • service provider e.g. ISP service provider
  • tasks may include addressing services, authentication/authorization services, naming services (DNS etc), basic IP connectivity service, session control means, service accounting, and a number of various value added services like firewalls, caches etc.
  • DNS naming services
  • Home domain is the domain where the DVB services are consumed. It may refer to one or more terminal devices in a single network or, alternatively, to a number of networks including a number of devices.
  • physical layer 108 includes the lowest-level interfacing means to transfer data between the ends of a communications link. It determines e.g. connector shapes and sizes, "bit" definitions and synchronization aspects in relation to, for example, voltage levels and different time durations or other physical magnitudes. Reference numeral 108 also refers to link layer that handles media access control functions like addressing, and optionally error control, flow control, and re-transmission of defectively received data packets.
  • Network layer 106 handles routing, packet segmentation/re-assembly etc functions relating to the whole end-to-end connection in question. In the case of IP networking such routing means addition of necessary IP addresses to sent packets.
  • network layer 106 does not have to be aware of lower level physical/link 108 layers.
  • Transport layer to which is likewise referred by collective reference sign 106 herein performs end-to-end type flow and error control functions and multiplexes a plurality of different services utilizing just a single IP link, for example. Multiplexing can be implemented by a plurality of different port numbers etc.
  • IP networks popular choices for a transport layer protocol are UDP (User Datagram Protocol) and TCP (Transmission Control Protocol) the latter of which provides also error detection/control on top of mere multiplexing.
  • Session layer 104 sets-up and releases connections for applications' use.
  • Application layer 102 includes applications and API(s) for interfacing them.
  • DVB context application layer 102 is specifically named as MHP (Multimedia Home Platform).
  • MHP Multimedia Home Platform
  • IP traffic for DVB services can be carried over by utilizing, for example, common Ethernet (e.g. 100BASE-T) [6] or IEEE 1394 [7] physical/network layer technologies.
  • the DVB data encapsulated in IP packets can be either multicast or unicast to the subscribers depending on the service.
  • IP multicast can be used for PayTV type transfer and IP unicast for video/audio on demand type service.
  • MPEG-2 is a powerful aggregate of video and audio coding methods that utilize a number of different compaction techniques with remarkably high compression ratios with one major downside; the used compression methods are lossy, i.e. some data is irrevocably lost during the encoding process. Without such sacrifice the achievable compaction ratios (now typically from 1:6 to 1:30 etc) would not be near as impressive, as being obvious though.
  • MPEG-2 coding also requires a considerable amount of processing, which, however, is generally not a problem with modern high performance processors anymore.
  • Figure 2 discloses a generic process of encoding audio/video signal 202 with an MPEG-2 compliant encoder 204 producing standardized MPEG-2 stream as output.
  • Audio/video server 206 receives and stores the encoded data stream, and eventually transmits it over transmission network 208 to receiver 210, e.g. a DVB set-top box connected to a television or a DVB IRD (Integrated Receiver Decoder) card installed therein, comprising necessary software/hardware means for decoding the stream for exploitation.
  • receiver 210 e.g. a DVB set-top box connected to a television or a DVB IRD (Integrated Receiver Decoder) card installed therein, comprising necessary software/hardware means for decoding the stream for exploitation.
  • MPEG type coding shares some parts with a common still picture compression format JPEG that utilizes characteristics of human vision and extracts normally invisible and in that sense unnecessary information from a source picture during the encoding process.
  • Encoding stage exploits e.g. Discrete Cosine Transform (time->frequency transformation) and entropy coding. High frequency changes in picture colour can be more easily omitted from the coded signal than high frequency luminance (brightness) changes to which the human eye is more sensitive.
  • MPEG exploits also temporal redundancy, i.e. static portions in consecutive video frames do not have to be coded for every frame; eventually, a content change within a certain area triggers sending of coded version thereof.
  • each pixel in a figure is parameterised with luminance/brightness value (Y) and two color vectors (U, V). Pixels are then grouped together to form blocks and groups of blocks called macro-blocks. Blocks shall be converted into frequency domain by utilizing DCT that is rather similar to a common Fourier transform. DCT results a number of coefficients describing the cosine functions formed from the block with increasing frequency. From such coefficients the spatial information carried by the blocks can be later resolved by the decoding unit. DCT transform output is then effectively quantized and Huffman coded. In Huffman encoding different symbols consume a variable number of bits. Frequently used symbols consume fewer bits and less frequently used symbols more bits.
  • I-frames intra-coded frames.
  • I-frames are likewise needed, when a service subscriber starts receiving the service stream for a first time or at least after a pause, and the receiver thus lacks the necessary data history for constructing valid decoded frames on the basis of mere differential data, for example.
  • Bi-directional frames utilizing information both from prior and following frames are called B-frames.
  • the above process is taken further by encoding motion vectors such that only portions of a picture that move or can be borrowed from other locations in previous frames of the video are encoded using fewer bits.
  • Four 8x8 pixel blocks are grouped together into 16x16 macroblocks. Macroblocks that do not change are not re-encoded in subsequent frames.
  • the encoder searches the previous frame (or frames before and after in case of B-frames) in half-pixel increments for other macroblock locations that are a close match to the information contained in the current macroblock. If no adequately matching macroblocks are found in the neighboring region, the macroblock is intra-coded and the DCT coefficients are fully encoded. If an adequate match is found in the search region, the full coefficients are not transmitted, but a motion vector is instead used to point to the similar block(s).
  • Macroblocks 302 and 306 corresponding to a same location in the signal source contain practically identical data in both the frames and encoding thereof may thus be omitted (in P-frames).
  • Macroblocks 304 and 308, to the opposite, have a changing element, caused by a man walking by in otherwise static meeting scenario, and have to be re-encoded.
  • motion vectors can be cleverly utilized in order to determine in the rightmost more recent frame a reasonable match with a macroblock in the previous frame on the left, see the dotted arrow highlighting this.
  • MPEG audio coding utilizes certain distinct properties of human hearing like auditory masking effect. Both temporal and spatial (in frequency plane) aspects are considered with impressive 1:10 compression ratios achievable again with only minor, if any, degradations perceptible in the decoded signal.
  • MPEG-2 has five channels for directional audio and a special low-frequency channel.
  • the encoded signal may also encompass a plurality of alternative language channels.
  • the mammoth MPEG-2 standard includes a somewhat large number of different video and audio modes
  • the preferred level of adoption especially in case of DVB services is determined in reference [8] to facilitate the hardware manufacturers' tasks as to the compatibility issues inevitably rising in otherwise a bit too diverse context.
  • DVB DVB Return Channel through Cable specification
  • DVB-RCC DVB Return Channel through Cable specification
  • routers and switches of the broadband network typically maintain the registration data in relation to each user's current channel selections or channel registrations/usage rights in general.
  • a terminal device at the receiving end may, as a response to a user generated channel join request inputted through a user interface such as a remote control etc, to send group join/release messages to a responsible network element like the aforesaid routers or switches by utilizing e.g. IGMP (Internet Group Management Protocol).
  • IGMP Internet Group Management Protocol
  • the existing services e.g. TV channels
  • the subscriber lines towards the users carry only data related to a single channel selected by each user at a time.
  • Such an arrangement is necessary as one channel may easily require a transfer capacity of 5 Mbit/s, for example. If e.g. a total of 100 channels co-exist, it's clear that a normal subscriber line hardly exceeding a data transfer capacity of 10 or 100 Mbit/s cannot be provided with that large number of channels continuously.
  • Picture 4 discloses the above scenario in which service provider 402, e.g. a broadcast/multicast station, is connected to DSLAM (Digital Subscriber Line Access Multiplexer) 406 via trunk network 404 capable of simultaneously transferring data channels related to all available services, e.g. TV channels, transmitted by service provider 402.
  • DSLAM 406 devices may be located, for example, on one unit per block/city district principle.
  • Subscriber lines 408 then carry only one program channel at a time and deliver it to receiving terminal 410 for the service subscriber's ( ⁇ service user) exploitation.
  • a receiving terminal device cannot immediately start decoding with a relatively high likelihood, as the next I-frame has to be waited for to acquire proper initial information for decoding.
  • non-predictive I-frames have to be sent approximately with a rate of one per second.
  • P-frames repeated transferring thereof in equal time with smaller P-frames requires also additional bandwidth. From a broadband service, e.g.
  • the object of the present invention is to alleviate the defects of prior art solutions due to the frequent transmission of large non-predictive frames and still immanent delay between every two subsequent non-predictive frames. Another object is to keep the need of additional resources required for attaining the alleviation low.
  • the object is achieved by buffering the overall service data stream including a number of service data streams each of which comprising both non-predictive and predictive data frames in a manner that whenever a service user initiates data reception of one of the data streams, the stream transmission to the user through a subscriber line is started from a location in a buffer carrying the latest or otherwise preferred non-predictive frame available.
  • the buffering may be performed by a device residing on the transmission path between the service provider server and the user terminal or by other receiving apparatus at the far-end.
  • a device may be, for example, a DSLAM switch at the border of a high ⁇ speed trunk network and a local network equipped with lower capacity subscriber lines.
  • the device has to keep track of the user-specific buffer read pointers in addition to mere knowledge about the existing linkage between a certain stream (channel) and connected users.
  • the utility of the invention is therefore based on a number of related issues.
  • the frequency of non-predictive frames' transmission can be lowered thus saving the transmission resources, the users may still benefit from the reduced delay as to the initiation of the service stream delivery as the transmission thereof can start immediately from the latest received and buffered non-predictive frame in the buffering device.
  • the invention is described herein by referring to the provision of interactive services utilizing especially DVB technology/equipment, particularly DVB-C and DVB over IP, both with MPEG-2 source coding, but also other digital broadband and/or broadcast systems with substantially similar characteristics may gain from using it.
  • DVB technology/equipment particularly DVB-C and DVB over IP
  • coding methods like MPEG- 1 , MPEG-4, H.263 and H.264 utilize an I/P-frame concept more or less similar to the one of MPEG-2, and thus it's obvious to a person of average skill that the invention could be utilized in systems initially exploiting one of the above or corresponding coding methods.
  • terminal equipment it is referred to e.g.
  • DVB IRD or "DVB set-top box" in more vernacular language, being a device with/connected to an external decoder in practise.
  • Data type refers to the nature of data, e.g. to video (picture) frame data or audio data.
  • a method to be performed by an electronic device for transferring a number of compressed data streams related to a service and transmitted by a service data source towards a number of decoders residing at the receiving end behind at least partially separate connections with said electronic device, said service data streams including both predictive and non-predictive data frames of a common data type, is characterized in that it has the steps of
  • the electronic device may be e.g. the DSLAM switch as generally presented hereinbefore in figure 4 or a corresponding entity located between a high-speed network and a local network with possibly lower speed individual subscriber lines only.
  • the device advantageously but not necessarily receives a plurality of service data streams, e.g. channels in the case of TV transmission embodiment, buffers and finally forwards them to the subscriber lines.
  • Data routing may be based on existing channel vs. (active) service subscriber registrations stored in a table etc.
  • connection(s) from the electronic device towards the decoder(s) are either fully separate from each other and diverge straight from the electronic device, or, alternatively, they comprise a shared part, e.g. a high-speed portion between the device and an actual router from which the separate connections to the decoder(s) are started.
  • Each decoder in said number of decoders is included in or connected to the receiving device such as a set-top box at the far-end. It is possible though that the same device includes a plurality of decoders, e.g. one for real-time enjoyment of a TV channel and the other for simultaneous recording of a second channel, and therefore the connection between the electronic device and the receiving device typically contains data stream related to a single service only further utilization thereof remaining still possible for additional streams.
  • One criterion belonging to the predetermined one or more criteria may indicate that the most recent non-predictive frame received (being typically equal to the last received non-predictive frame in relation to the stream content and e.g. a time code thereof as well) shall be selected as the first frame to be transmitted upon service data delivery over a certain subscriber line to minimize the overall delay, notwithstanding the possible insignificance of the overall delay as such, but also other criteria can be defined and stored in the device either completely locally (pre-programmed or entered through a maintenance UI) or received from a main user/service provider or a service user through external connections.
  • a device capable of transferring a number of compressed data streams related to a service and transmitted by a service data source towards a number of decoders residing at the receiving end behind at least partially separate connections with said electronic device, said service data streams including both predictive and non-predictive data frames of a common data type, said device comprising processing and memory means for processing and storing instructions and data, said device further comprising means for receiving and transmitting data, is characterized in that it is configured to receive frames of a service data stream to be buffered at least for the duration between two non-predictive frames, to detect the non- predictive frames in the received service data stream, upon initiation of the service data stream delivery towards a decoder to select a proper received and still buffered non- predictive frame of the service data stream according to a number of predetermined criteria, and to transfer service data stream towards the decoder starting from the selected non-predictive frame.
  • FIG. 1 illustrates the utilization of IP network as a delivery network of DVB service data.
  • Fig. 2 depicts the typical MPEG-2 transmission system.
  • Fig. 3 illustrates both spatial and temporal aspects of MPEG-2 source coding.
  • Fig. 4 depicts a service delivery over DSL/cable network and a DSLAM to a DVB set-top box.
  • Fig. 5 depicts the DSLAM internals.
  • Figs. 6A and 6B depict variants of one possible buffering arrangement in accordance with the invention.
  • Fig. 7 discloses a flow chart of the method of the invention.
  • Fig. 8 is a block diagram of a device capable of acting as a DSLAM.
  • Figure 5 discloses DSLAM internals considered as especially relevant from the invention's standpoint.
  • the figure is an exemplary only and it's clear to a skilled person that modifications may be introduced thereto without diverging from the actual inventive concept.
  • Input data includes service data frames of non-predictive or predictive content. In the case of MPEG-2 the frames are called I- and P-frames, respectively. Such system-specific terms are also used below for readability.
  • the received frames may be extracted from a carrier frame structure if necessary. Then the frames will be driven through I-frame detector 504 to find and locate the I- frames in the overall service data stream.
  • the analysis performed by the detector shall be based on the 'most convenient technique available. For example, if a TV transmission has been compressed with MPEG-2 transport stream format, the beginning of an I-frame can be easily found out by examining the values of "random_access_indicator" field present in the transport-stream packets. If the field is valued "1", an I-frame begins in the same transport stream packet.
  • supplementary classification information may be at least logically attached thereto to point out their special nature also later on while buffered for transmission.
  • Buffer 506 is constructed for each service stream like TV channel and comprises enough space to accommodate frames equivalent to e.g. 5-10 seconds time period, being in practise a duration including a plurality of I-frames if properly received.
  • Another, more straightforward option is to utilize a common buffer for all received data and just mark the frames in relation to the related channels/service users. Anyhow, a number of decoders ( ⁇ service subscribers/users) may utilize the same buffer as one buffer index pointer is independently created for each active receiving party.
  • the buffer index pointer determines each user's location in the buffer by specifying the current frame, "current" being the one to be sent next, for example.
  • the buffer can be implemented as a FIFO buffer familiar to persons skilled in the art.
  • DSLAM 502 advantageously maintains information about active users (which users are on which channel), I-frames, and user-specific buffer index pointers.
  • DSLAM 502 Upon noticing a registration by a user to a new channel, for example receipt of a join request, DSLAM 502 makes the necessary preparations such as creation and initialisation of a buffer index pointer and starts transmitting the service data. The transmission is initiated from a frame complying best with the predetermined criteria.
  • Both the data reception/transmission and buffer updates preferably occur at constant speed, fluctuations being, however, possible to be minimized by the sufficient buffering.
  • One criterion in cases where the initiation of the service data delivery should be immediate but the overall transfer delay still minimal would indicate the selection of the latest received I-frame whereas in a scenario where more delay is tolerated some formed but yet buffered I-frame can be selected instead to provide additional buffering protection against unstable frame reception rate or transmission errors/frame re- transmission delays.
  • FIG. 6A One option for carrying out the above buffering is depicted in figure 6A wherein frames of an input stream relating to a service are stored in a FIFO buffer that forwards the data included in the buffer slots (one frame per slot) step by step 602 in a timed manner.
  • a new personal buffer index pointer is created for him (or, in practise, for the decoding device etc of the user) and associated with the most recent I-frame 604 in the buffer.
  • correspondingly frames entered into the location(s) of active existing user index pointers are sent forward through the subscriber lines as sketched in the figure within dash line 606.
  • the user enters the channel the buffer of which has been depicted and the buffer index is associated with the oldest I-frame left in the buffer with reference numeral 608.
  • the DSLAM may still send a re-send request to the service provider and possibly receive the re-transmitted frame and place it in the buffer before the corresponding empty slot passes the buffer index position from which the frames are transferred forward to be sent over the subscriber line.
  • the last slot in the buffer is logically funnelled into a trash can/deletion of the related data, and in practise the same result is achieved by doing nothing; the data in the previous buffer slots is transferred forward starting from the slot adjacent to the last one, and thus the last slot is automatically periodically deleted (overwritten).
  • Figure 7 discloses one option of a flow diagram for carrying out the method steps of the invention.
  • a device such as the aforementioned DSLAM switch functioning as a data forwarding/routing device loads data transfer and general control applications to the memory thereof, initialises required memory areas and variables, establishes necessary connections on the basis of e.g. received service requests, and initiates reception and delivery of the service data comprising encoded service data frames stored in a number of buffers.
  • a receiving device such as a set-top box with a decoder may execute the corresponding functions related to especially controlling and decoding of the service data.
  • the flow diagram has been created by focusing on the inventive issue upon start-up of a service data delivery towards a newly registered user and his decoder.
  • the service delivery towards previously registered decoders continues normally and is not depicted in the figure for clarity reasons only.
  • phase 704 the device receives service data to be buffered in service, e.g. channel, specific or common buffer(s).
  • service data e.g. channel, specific or common buffer(s).
  • Non-predictive frames are detected in phase 706 by relying on the distinctive features thereof. Note, that the incoming frame can be first inserted in the buffer and then exposed to the non-predictive frame detection manoeuvres. Alternatively, the frame can be first checked for non-predictive nature after which the actual placement in the buffer occurs.
  • phase 708 it is checked by traversing through the received join requests, for example, whether new connection(s) shall be established. If that's the case 710, one of the number of detected non-predictive frames still in the buffer is selected based on the preferred criteria as discussed earlier and a corresponding user (decoder)-specific buffer index pointer is created. Otherwise, there's no need to establish new connections and the rest of the steps are omitted, data reception, however, continuing to serve the existing and possible future connections. In step 712 data transmission is initiated from the selected frame. The service delivery initiation procedure is finally terminated in step 714.
  • Figure 8 discloses a block diagram of basic components for a device such as a computer capable of acting as a DSLAM switch for delivering encoded data with both predictive and non-predictive frames.
  • Processing unit 802 controls the execution of actions in accordance with instructions 805 e.g. in a form of an application including data frame classification routines stored in memory 804.
  • Memory 804 may also comprise necessary settings and other supplementary information.
  • Data transfer means 808 may include both wireless means 814 like a radio/infrared transceiver and also wireless network (WLAN etc) adapters, or fixed means 812 such as a conventional network adapter (Ethernet card etc), for example.
  • Data transfer means for the service data reception e.g.
  • All cable TV channels are received through a single trunk connection may be able to handle higher data rates than the means for outputting the service-specific (e.g. one TV channel selected per (DSL) subscriber line) data streams over the subscriber lines towards the users.
  • Keyboard or other data input means 810 and display 806 are useful in providing a user with an interface for managing and controlling the device.
  • the software for implementing the invention and method steps thereof can be delivered on a carrier medium such as a floppy, a CD-ROM, a memory card, a hard disk etc.
  • the protocols and protocol stacks utilized in service data transfer according to the invention can be selected from the existing ones as the transfer capabilities required for implementing the invention as such are not particularly complex or special, which can be seen as one benefit of the invention.
  • the invention may be realized as an additional software/hardware module or a combination of both as included or at least connected to the device.

Landscapes

  • Engineering & Computer Science (AREA)
  • Signal Processing (AREA)
  • Computer Networks & Wireless Communication (AREA)
  • Computer Security & Cryptography (AREA)
  • Multimedia (AREA)
  • Compression Or Coding Systems Of Tv Signals (AREA)

Abstract

La présente invention a trait à un procédé et un dispositif pour le transfert de flux de données de service tels qu'un signal vidéo comprimé comportant à la fois des trames de données non prédictives et prédictives d'un type de données commun. Une pluralité de flux de données de service différents sont reçus par un dispositif (406) à travers une connexion haut débit (404) pour une nouvelle distribution sélective à des utilisateurs de services (410) sur les lignes d'abonnés à capacité inférieure (408). Le dispositif (406) met en mémoire tampon les flux entrants et y détecte les trames non prédictives. Lors du début de la distribution de données de service vers un certain utilisateur de services, la transmission démarre à partir de la trame non prédictive reçue le plus récemment et encore tamponnée.
PCT/FI2004/000414 2004-07-01 2004-07-01 Procede et dispositif pour la distribution de donnees de service WO2006003234A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/FI2004/000414 WO2006003234A1 (fr) 2004-07-01 2004-07-01 Procede et dispositif pour la distribution de donnees de service

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/FI2004/000414 WO2006003234A1 (fr) 2004-07-01 2004-07-01 Procede et dispositif pour la distribution de donnees de service

Publications (1)

Publication Number Publication Date
WO2006003234A1 true WO2006003234A1 (fr) 2006-01-12

Family

ID=35782492

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/FI2004/000414 WO2006003234A1 (fr) 2004-07-01 2004-07-01 Procede et dispositif pour la distribution de donnees de service

Country Status (1)

Country Link
WO (1) WO2006003234A1 (fr)

Cited By (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104735394A (zh) * 2013-12-19 2015-06-24 广州市地下铁道总公司 一种用于城轨列车的视频点播方法和系统
US20230217060A1 (en) * 2021-12-30 2023-07-06 Comcast Cable Communications, Llc Systems, methods, and apparatuses for buffer management

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0614186A2 (fr) * 1993-03-04 1994-09-07 Canon Kabushiki Kaisha Appareil de transmission
EP0643537A2 (fr) * 1993-09-10 1995-03-15 Koninklijke Philips Electronics N.V. Dispositif pour transmettre une pluralité de signaux de télévision par l'intermédiaire d'un canal de transmission
WO2001078408A2 (fr) * 2000-04-07 2001-10-18 Omneon Video Networks Procede de creation d'estampilles pour donnees isochrones
US6546013B1 (en) * 1997-03-21 2003-04-08 Scientific-Atlanta, Inc. Method and apparatus for delivering reference signal information within a specified time interval
US6680944B1 (en) * 1998-03-09 2004-01-20 Sony Corporation Apparatus for and method of predictive time stamping of isochronous data packets transmitted over an IEEE 1394-1995 serial bus network
EP1443770A2 (fr) * 2003-01-29 2004-08-04 Hewlett-Packard Development Company, L.P. Codeur et procédé de codage

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP0614186A2 (fr) * 1993-03-04 1994-09-07 Canon Kabushiki Kaisha Appareil de transmission
EP0643537A2 (fr) * 1993-09-10 1995-03-15 Koninklijke Philips Electronics N.V. Dispositif pour transmettre une pluralité de signaux de télévision par l'intermédiaire d'un canal de transmission
US6546013B1 (en) * 1997-03-21 2003-04-08 Scientific-Atlanta, Inc. Method and apparatus for delivering reference signal information within a specified time interval
US6680944B1 (en) * 1998-03-09 2004-01-20 Sony Corporation Apparatus for and method of predictive time stamping of isochronous data packets transmitted over an IEEE 1394-1995 serial bus network
WO2001078408A2 (fr) * 2000-04-07 2001-10-18 Omneon Video Networks Procede de creation d'estampilles pour donnees isochrones
EP1443770A2 (fr) * 2003-01-29 2004-08-04 Hewlett-Packard Development Company, L.P. Codeur et procédé de codage

Cited By (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104735394A (zh) * 2013-12-19 2015-06-24 广州市地下铁道总公司 一种用于城轨列车的视频点播方法和系统
CN104735394B (zh) * 2013-12-19 2019-03-05 广州地铁集团有限公司 一种用于城轨列车的视频点播方法和系统
US20230217060A1 (en) * 2021-12-30 2023-07-06 Comcast Cable Communications, Llc Systems, methods, and apparatuses for buffer management
US11968417B2 (en) * 2021-12-30 2024-04-23 Comcast Cable Communications, Llc Systems, methods, and apparatuses for buffer management

Similar Documents

Publication Publication Date Title
US20110219414A1 (en) Method, apparatus, and system for switching channels
EP1766981B1 (fr) Procede et dispositif permettant le transfert de trames de donnees predictives et non predictives
US8935736B2 (en) Channel switching method, channel switching device, and channel switching system
EP1987668B1 (fr) Ajustement rapide dans des applications multimedia
USRE50398E1 (en) Device, method and system for media packet distribution
US20070266398A1 (en) Method for fast zapping between tv channels
WO2000070840A3 (fr) Procede d'acheminement de donnees ip sur des reseaux de transport mpeg-2
WO2008037218A1 (fr) Procédé, système et serveur multimédia permettant une commutation rapide d'un canal de télévision sur internet (iptv)
EP1783980A2 (fr) Traduction d'identificateur de programme (PID) du côté-client
US8667554B2 (en) Method and a device for supplying a decoder with data
Bing 3D and HD broadband video networking
KR100906981B1 (ko) 버퍼링 서버를 통한 ｉｐｔｖ 채널 변경 속도 개선 방법
WO2006003234A1 (fr) Procede et dispositif pour la distribution de donnees de service
Uzunalioglu Channel change delay in IPTV systems
KR100861239B1 (ko) 디지털 방송 및 ｉｐ 방송의 다수가 이용할 수 있는공청방송과 공청방송에서 양방향 통신지원을 위한 ｉｐ미디어 게이트웨이
Koo et al. Adaptive channel control scheme to reduce channel zapping time of mobile IPTV service
US20080120672A1 (en) Methods and Apparatus for Weighted Multicasting of Data Streams
KR20070048663A (ko) 디코더에 데이터를 공급하는 방법 및 디바이스
Lee Video-on-Demand
Cucej Digital broadcasting and new services
Čučej Digital broadcasting and new services

Legal Events

Date Code Title Description
AK Designated states

Kind code of ref document: A1

Designated state(s): AE AG AL AM AT AU AZ BA BB BG BR BW BY BZ CA CH CN CO CR CU CZ DE DK DM DZ EC EE EG ES FI GB GD GE GH GM HR HU ID IL IN IS JP KE KG KP KR KZ LC LK LR LS LT LU LV MA MD MG MK MN MW MX MZ NA NI NO NZ OM PG PH PL PT RO RU SC SD SE SG SK SL SY TJ TM TN TR TT TZ UA UG US UZ VC VN YU ZA ZM ZW

AL Designated countries for regional patents

Kind code of ref document: A1

Designated state(s): BW GH GM KE LS MW MZ NA SD SL SZ TZ UG ZM ZW AM AZ BY KG KZ MD RU TJ TM AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HU IE IT LU MC NL PL PT RO SE SI SK TR BF BJ CF CG CI CM GA GN GQ GW ML MR NE SN TD TG

NENP Non-entry into the national phase

Ref country code: DE

WWW Wipo information: withdrawn in national office

Country of ref document: DE

32PN Ep: public notification in the ep bulletin as address of the adressee cannot be established

Free format text: NOTING OF LOSS OF RIGHTS PURSUANT TO RULE 69 ( 1 ) , EPC, EPO FORM 1205A SENT ON 01/06/07 .

122 Ep: pct application non-entry in european phase
点击 这是indexloc提供的php浏览器服务，不要输入任何密码和下载