DE102006011628B4 - Method for operating a data transmission network - Google Patents

Abstract

A method for transmitting program data from a provider of programs, such as data, information content, and / or services, to a plurality of users,
wherein for each of the programs a data stream with a low data rate or bandwidth is transmitted by the provider for each of the programs in the broadcast method, and
upon request by a user to at least one of the programs, at least one first data stream with high data rate or bandwidth is transmitted in the multicast method,
wherein the at least one first data stream contains the data requested by the user or the at least one first data stream contains the data requested by the user together with the further data stream or bandwidth transmitted to the requested program.

Description

Increasingly are being used with the expansion and proliferation of packet-switched Networks, such as e.g. Internet or Public Ethernet, broadband network access for a variety easier and cheaper for users available, be it via DSL, optical access networks or WLAN or Wimax. With such a comfortable Network access is a wealth accessible by new or already known services, such as Internet access, Voice over IP, IP Television, by different service or Provided to content providers. Typical content, for example about such broadband networks available are computer games, music data and video data, so in particular Television programs. All these services are available in the present Font under the generic term "program" called.

The Data rate in the distribution of video data required for high-quality transmission of images and high quality sound are necessary, however, are so high, that the user is not as usual on antenna or satellite operation usual all Programs in the same quality simultaneously, i. in the broadcast process can be. This is among the currently available Bandwidths in IP networks can not be realized.

Now On the one hand, it is conceivable that each user individually from one Provider video data, for example films, on individual request, i.e. in the unicast method. This shipment of streams is then individual. Independently Only the data stream or program is targeted by a schedule sent, which was requested. If such services are provided by a Variety of users are requested, so will the data stream sent several times and the corresponding network heavily charged.

resource-saving on the other hand are multicast methods, in which for example video files be offered at a fixed time to users who are certain user groups, the individual programs choose and then also transmitted to get.

in the Multicast method it is possible that users connect to appropriate groups and a number of video files or data streams from the provider at the same time is sent to the different user groups. It is crucial that the multiplication of the corresponding video data only happens at the branches where smart switches the data distribute to different branches of the network, to the different ones Users who have ordered the data. The provider is therefore not burdened with a multiplication of the data itself. Overall, in such a multicast method with resources the network was sparing.

Want a user from one multicast user group to another group change, i. for example, receive another video program, so he must first tell the provider or network that he is the old program does not want to receive anymore, so he is off the list the multicast receiver the first data stream is deleted, and at the same time it shares the user or the network that he has another data stream receive, i.e., want to belong to another multicast user group. Of the appropriate program change provides that different intelligent Switches in the network which switch off a data stream and another data stream to the user who wishes to change, by turn.

Of the actual program change requires a few seconds in the network and leads for a corresponding waiting time at the user. If the user video signals viewed directly on a screen, arises for him at Switch an annoying Dead time that he of the classical antenna operation or cable operation not used to it.

The WO 2005/043783 A1 proposes to solve the Problems of waiting time when switching between channels in one Time slice system, a first stream for batch sending a Packet and a second stream for continuous transmission of a packet to be multiplexed together and then transmitted.

During the Switching becomes the second data stream which is transmitted continuously is used to play the content. After completion of the Switching becomes the first data stream in which the packet is transmitted in batches, played.

The WO 2004/051926 A1 describes a method for transmitting multicast data to a multicast user group, wherein multichannel multicast groups are provided, wherein each multichannel multicast group transmits at least one channel. The Availability and configuration of multichannel multicast group will be available to users by an announcement multicast group displayed.

The EP 1 601 199 A1 describes a method for reducing latency when switching between channels in a broadband telecommunication system having a plurality of content servers. The content servers are connected to an ADSL Subscriber Access Multiplexer via a switch box which merges the channels in a composite channel. If a user egg NEN requests a selected channel and this is not immediately available to the ADSL Subscriber Access Multiplexer, it provides the user immediately the composite channel until the ADSL Subscriber Access Multiplexer receives the requested channel directly from the corresponding content server.

The The present invention has for its object the switching from a first program to another program within a network of the type described above for a user as possible pleasant, comfortable and resource-saving.

The The object is achieved by the method according to claim 1. advantageous Further developments of the method are given in the dependent claims.

there The object relates to a method for transmitting program data from a provider of programs, such as services or informational content (Content), to one or more users, one or more groups by users or all users. For this data streams are transmitted, of which for the respective user in each case at least one first data stream in Multicast method for immediate or timely use in the desired by him quality is provided, wherein for a user different data streams are selectable for use. All users will also at least several of the available Programs by means of a data stream of low bandwidth or data rate over the Broadcasting available posed. The low bandwidth or data rate may be due to reductions in the resolution (optical / acoustic in television programs), the refresh rate, the color information, etc. are achieved.

Thereby, that the user additionally to the first data stream a further data streams in the broadcast method for disposal stands, he can orientate himself, which further data for him directly and can be used in a timely manner. It is characterized by the fact that the further data stream transmitted in a reduced form will, capacity the data transmission network saved up. On the other hand, the transmission of basic information about the Programs in the broadcast process, the administrative burden in the network limited.

Of the For example, the first further data stream may itself be a video data stream which is available in reduced quality and on request in improved quality transmitted as the first data stream can be. However, it is also conceivable that the further data stream Data about others about indirect Data streams, for example in the form of a program overview or in the form of still images or images of very low frame rate of different video programs contains. Ultimately, the further data stream can also be compressed with a low quality loss Be video stream.

Around a sufficient one Reduction of data streams The scope of use and / or the quality of the other can also be achieved streams limited be.

Important is that in total the data rate of the data to be transmitted, the capacity of the network does not exceed.

at the transmission of further data streams in the broadcast process transfer them for free be while the transfer a high-quality data stream in the multicast method may be charged. For billing etc. are therefore also the Join and leave commands, with which a user the transmission requesting a first data stream in the multicast method, always transmitted to the provider of the program, however, already implemented the appropriate switching commands independently at a suitable node can be.

in the Case of video data, this means that the currently used program in optimal quality User submitted will, while other data streams, the other receivable programs represent, in greatly reduced and / or compressed form ("Basic Streams ") become. This is sufficient, for example, for a synchronous representation many small screens on a viewing screen, so that At a glance, various offered programs are recorded can. In this case, the first data stream is still sent, its video display in the best quality preserved. This can, for example, as a background image for the representation of as small images represented other programs / others streams be used.

the Users can dependent on from the content of the first data stream it currently receives further data streams be transmitted in appropriate degrees of reduced form.

there can be taken into account, for example, that the user usually of first data streams switching certain contents to certain other data streams, for example, video data from a first program as soon as This sends advertising, switches to a specific other program.

There may also be other usage habits units of the respective user are recorded and taken into account, so that, for example, when switching data streams from the user a certain order is met, and that the correspondingly most likely in the future selected data streams are provided in a reduced form, but in the best possible quality , However, other data streams / programs, which are more remote for the respective user according to experience, can be transmitted to a degree that is the most severe.

Around the best possible resource savings in the data transmission network use, has this smart switch at branch points, which switch the extensive first data streams only to the users, who have selected these while the reduced further data streams also to the other users be switched through. In this way, the first data streams, the each selected by users are, in the so-called multicast method, in which the provider send out the data stream once and this through intelligent switches is multiplied at branch points as needed. All in all is for the transmission these data streams minimized to a variety of users the effort.

The further data streams are disseminated in a reduced form in the broadcast process, i. she become all users of the data transmission network to disposal posed. It can the other data streams be reduced so far that no overloading of the network is to be feared.

The Reduction of the further data streams can in principle be designed to contain basic data that has a reduced, i.e. allow less comfortable use of the data stream, with video data for example, a noisy or reduced in size Image. additionally can they Data to be compressed. these can then, when the corresponding first data stream is selected, through enhancement data streams to a complete high-quality data stream to be completed.

This has the advantage that the basic data stream is constantly received by the user and the enhancement data stream is only enabled in the case of selection, transmitted to the user as well as there needs to be synchronized with the basic data stream.

Of the Users who want to change the data stream can talk about his Choices, especially with video data about the selectable Programs based on, for example, a multiple screen overview an overview and then the desired Select program. The appropriate switching in the network requires a few seconds, while of which the basic data stream of the selected data stream has already been used can be. In this way, in the case of video data, the user already get an idea of what program he will see and also the sound may already be heard.

The Distribution of data streams in basic data streams and enhancement data streams has the advantage that the enhancement data streams are not complete information must contain but on the basic data streams can put on so that the load on the network as a whole is reduced.

In In the event that a user wants to switch the first data stream, it will a first signal (leave) sent to the provider with the content, that the previous first data stream is no longer received should. A second signal (join) is sent to the provider concerning the stream of data, which the user in the future in unreduced form wants to get. These commands / signals are transmitted via IGMP (Internet Group Management Protocol) or GARP (Generic Attribute Registration Protocol) or PIM (Protocol Independent Multicast) or GMRP (GARP Multicast Registration Protocol), depending on whether they are within an Ethernet or the Internet are sent. It is caused that the smart switches in the network correspond to the current ones first data stream for lock the user and the desired one switch through the new data stream to the user. The previous one Data stream will continue to be sent in a reduced form to the user.

He can also remain on an IGMP pre-join list and therefore continue be transmitted to a user-friendly switch and thus easier / faster available be than other data streams, allowing a quick change back possible to the previous program is.

Thereby, that constantly representations all available streams for the Users accessible are, this can choose comfortably. As for the multiplicity of data streams / video data not the complete ones Data streams transmitted can be so as not to overload the network, will be a corresponding overview transmitted in the form of reduced data streams. In any case, this gives the user the feeling of having a sufficient overview of the To be able to procure an offer and is suitable to bridge the time during the the network changes to the desired data stream / desired Video program.

In the following the invention with reference to an embodiment in a drawing is shown and subsequently described. Showing:

1 a data transmission network with three users receiving two different first data streams,

2 a screen view of a so-called zapping preview,

3 a data transmission network with three users, according to the invention, basic data streams are sent to the user and each of the selected first data streams enhancement data streams are received.

In the 1 are two content providers 1 . 2 shown that spread data over the Internet, for example in the form of data streams such as video streams. This can be done, for example, in the form of the transmission of television programs over IP (IPTV). The first content provider 1 sends - represented by the dotted lines - two different programs, one to an input node 3 . 4 , which are arranged in the so-called Public Ethernet. Public Ethernet is over the nodes 3 . 4 Connected to the Internet and obtains from there data. From the entrance nodes 3 . 4 The data streams are handled by intelligent switches, so-called switches in Public Ethernet 5 forwarded, the switches with the reference numerals 6 . 7 . 8th . 9 . 10 . 11 . 12 . 13 are designated. The data streams are in the case shown here to the users 14 . 15 . 16 directed.

For this purpose each access node 17 . 18 provided, which are directly connected to the respective gateway of the user. The gateways are with 14a . 15a and 16a designated. Behind the respective gateways can be a home network with telephone, 14b , PC 14c and TV 14d ,

The intelligent switches 6 - 13 are interconnected such that data streams may, if necessary, be redirected between them when required to reach particular destinations, such as users, or vice versa, from a user to certain input nodes 3 . 4 to reach.

In the case illustrated it becomes clear that the users 14 . 15 the same data stream, ie the same video program 19 received in the access node 17 is doubled.

This, also called multicast method brings with it the advantage that of the content provider 1 Each program must be sent only once and that this is multiplied by network elements in the Public Ethernet as needed. As a result, multiple identical data streams are passed through small parts of the network only when needed and the total network load is kept as low as possible.

The user 16 receives the program as its first data stream 20 as the only one.

Now the user wants 15 from the program 19 on the program 20 switch, he communicates his wish to the nearest network elements which receive the corresponding data streams. First, he sends the provider the command "leave" that he is the program 19 do not want to receive anymore. The access node 17 also receives the command "leave", represented by the arrow 21 , The access node 17 sets the doubling of the corresponding data stream and henceforth only supplies the user 14 , In addition, the user sends 15 the command "join", represented by the arrow 22 , to the content provider. The switch 10 who the program 20 gets and tight with the switches 6 . 7 . 8th . 9 is connected via links not shown here, about which the user 15 is serviced, recognizes the joint command. Inside the switch 10 then can the program 20 doubled and sent to the switch 9 , from there to switch 6 and switch 7 and from there to the access node 17 be directed. From there, the user receives 15 then the program 20 ,

The program change process described above will take several seconds to complete 15 possibly none of the programs 19 . 20 or neither of the two data streams available.

This phenomenon is unfamiliar to the user, especially when watching TV programs and should be avoided at all costs.

It is therefore aimed at giving the user several programs simultaneously in different qualities to disposal to provide or more data streams in different reduced form.

For the example of video data is in 2 illustrated how a screen might look for the user when on the main screen 23 the program considered so far is displayed as a background image, while the eight remaining programs to be selected 24 . 25 . 26 . 27 . 28 . 29 . 30 . 31 in the form of reduced images in reduced quality (thumbnails) are available. These are broadcasted to all users. A user can then select from among these smaller images, and a certain amount of time passes in this selection process, so that upon final confirmation by the user, the new program is either already available or can be made available in a short time.

In addition, can be provided that the corresponding data streams already Basic data streams represent by a complementary enhancement data stream only supplemented so that the extra Information that needs to be added after selecting a particular program, represents only part of the total data stream and the corresponding ones Switching processes can be accelerated.

In the 3 the method of a program change is shown in more detail due to the operation of the data transmission network according to the invention.

Around switching from one data stream to another more comfortable make the program change, especially in video programs accelerate, the inventive method sees a combination between broadcast and multicast. This will be the video information divided into two or more different variants or partial data streams. In this case, on the one hand, the data stream can be transmitted in a broadcast method low bit rate basic stream (basic data stream) and several of these supplementary transmitted in the multicast method Enhancement streams are divided. However, it can also be provided be that a low-bit-rate version of the data stream and as a higher-valued Copy a broadband version is provided, which is the bit-rate Makes version redundant. It will still be broadcasted. The base stream can then be used, for example, to correct the error serve broadband data stream. The different data streams will be in the data transmission network disseminated differently. The low bit-rate basisstreams of all Data streams / video programs be constantly sent as a broadcast to all reachable customers / users in the network. Such a base stream may indeed in the case of a video program show the complete TV picture, but its quality is lower, For example, at a data rate of 1150 kilobits, it can be VCD format match while the first data stream as a full video stream in DVD format (4-8 megabits) or in HDTV format (9-13 Megabits) may be present.

Thereby, that all data streams / video programs in the (reduced) basic quality Broadcasted to all users, these can be shared between programs or data streams quickly and switch comfortably. A program that will be considered longer will in improved quality received with high data bit rate.

In the 3 this is for example due to the first data streams 32 . 33 each presented in full quality to the users 14 . 15 or in the case of the data stream 33 to the user 16 be transmitted.

In addition to the users 14 . 15 a data stream 34 transferred in the access node 17 is doubled and branched and the one data-reduced variant or a base data stream of the first data stream 33 represents. This one will be on the switch 10 disconnected and over the switches 6 and 7 the access node 17 fed.

In addition, the user will 16 a data stream 35 forwarded to the switch 6 from the first data stream 32 is branched off and a data-reduced variant of the data stream 32 represents. This reduced data stream is transmitted via the access node 18 the user 16 fed.

Thus, in the simplified example described, each of the users receives 14 . 15 . 16 a first data stream with a video program of good quality and additionally each a reduced further data stream, which represents a video image in degraded quality. The respective deteriorated quality video image may, for example, be viewed and selected as a small image against the background of the better quality video program. Of course, instead of the reduced further data stream, a plurality of correspondingly reduced data streams can be transmitted and be available for selection.

For the selection, the example of the user 15 is presented, who wants to change the program, it is provided that the user 15 a command 36 (join) to the switch 10 gives the program / the first data stream 33 in optimal quality. This leads in place of the previously passed on reduced data stream 34 a higher-quality and data-rich data stream to the switch 6 further from where this data stream is via the switch 7 and the access node 17 to the user 15 arrives.

In addition, the user sends 15 at the access node 17 a command "leave" 37 that causes the access node 17 the program in the form of the data stream 32 not continue in full quality with the highest bitrate to the user 15 sends.

When the commands "join" and "leave" are completed, the program change is for the user 15 completed and the corresponding network elements 6 . 10 . 17 have redirected the data streams.

If more than two different data streams exist in different qualities, forecasts can also be made in the data network (eg at the provider) or in the terminal as to which data streams in the near future can be requested by certain users in an improved, data-rich form with high probability, and such switching processes can already be prepared so that the actual implementation is accelerated and the process is made more comfortable for the users.

It can also more than two quality levels be provided, wherein a first enhancement data stream, the one across from the minimum version of the data stream has improved quality or a differential data stream that is the basic data stream completed, broadcasted to the access nodes, but not to the end users. The moment an end user to the appropriate program or data stream in improved quality wants to access he already has the basic data stream and can in no time from his access node refer to the first enhancement data stream. In a next step Then, by means of the network elements involved, a further enhancement data stream is added the user who further completes the data stream or in the case of a video program, the image and the sound to reach Perfection completed.

Advantageous in coordinating the "join" and "leave" commands, i. at the Ordering and unsubscribing certain high-quality data streams is, that a new data stream in improved quality only then passed to the user becomes, if the current data stream is no longer the user reaches the user or not in the previous high quality not too many high-quality programs at the same time transmitted to various users and overloading the network in terms of bandwidth. Therefore recommends it is, a certain delay between the "leave" command, which will be executed first must, and the "join" command, which causes that a new data stream is directed to the user, a delay is provided becomes.

Yet succeeds with the method according to the invention also for IP TV a convenient selection and switching process of data streams, in particular Television programs.

Claims (13)

Method for transmitting program data from a provider of programs, such as data, information content, and / or services to a majority of users, being from the provider for each of the programs has a low data rate / bandwidth data stream Broadcast transmitted will and on request by a user to at least one the programs at least a first data stream with high data rate or bandwidth is transmitted in the multicast method, in which the at least one first data stream requested by the user Contains data or the at least one first data stream together with the to the requested program further data stream with low data rate or bandwidth from the User requested data. Method according to the preceding claim, characterized characterized in that for each program one or more first in the Multicast to be transmitted streams are requestable in terms of their data rate and / or bandwidth where each of the first data streams requested by the user Contains data. Method according to one of the preceding claims, characterized characterized in that for each program several first in the multicast Requestable data streams to be transmitted where each first data stream (enhancement data stream) is that data contains which are transmitted together with other broadcast and / or multicast methods streams the use of the program on a larger scale or in better quality allows. Method according to one of the preceding claims, characterized in that for transmitting the further data streams lower resources of the data network for transmission ( 34 . 35 ) are required to the user. Method according to one of the preceding claims, characterized in that the further data streams have a low data rate and / or low bandwidth the user only a reduced scope of use and / or a reduced quality of use. Method according to one of the preceding claims, characterized in that the user ( 14 . 15 . 16 ) at the same time various other data streams are transmitted in the broadcasting method, which are subject to different degrees of reduction. Method according to one of the preceding claims, characterized in that the user depending on his recorded usage habits certain additional data streams ( 34 . 35 ) are transmitted in appropriate degrees of the reduced form. Method according to one of the preceding claims, characterized in that the data transmission network at branching points has intelligent switches (switches) ( 6 . 7 . 8th . 9 . 10 . 11 . 12 . 13 ), and that transmitted in the multicast data streams are transmitted only in such areas of the network, where they are at least one Users ( 14 . 15 . 16 ) as the first data streams ( 32 . 33 ) are selected for use. Method according to one of the preceding claims, characterized characterized in that the data streams video data and / or audio data contain. Method according to one of the preceding claims, characterized in that it is detected and stored according to which pattern a user ( 14 . 15 . 16 ) Selects programs for use and / or which was the last previously used program and / or which program is adjacent to the currently used program in terms of user selection, and on the basis of which information is at least one most likely immediate prediction Future for use selected first data stream is determined, and that at least one of or at least the most likely selected in the future first data stream in a form extended to the reduced form at the same time to the currently selected first data stream is transmitted to the user. Method according to claim 10, characterized in that that in the pattern the as usual determined order of switching programs becomes. Method according to claim 10, characterized in that that when determining the pattern switching programs to contents of the data streams is related. Method according to one of the preceding claims, characterized in that a user, ( 14 . 15 . 16 ) if he wants to change the program, a first signal (leave) ( 37 ) of the content to corresponding network elements or the provider sends that he no longer wants to receive the previous first data stream and a second signal ( 36 ) (join) regarding the data stream that it wants to receive in unreduced form in the future, and that the provider or the network uses intelligent switches in the data transmission network to obtain the corresponding current first data stream ( 32 . 33 ) locks for the user and turns on the desired new first data stream to the user in unreduced form.