EP2215845A2

EP2215845A2 - Optimized method of transmitting layered contents to mobile terminals and via a radio infrastructure with access procedure of tdm/tdma/ofdma type, and associated processing device

Info

Publication number: EP2215845A2
Application number: EP08842276A
Authority: EP
Inventors: Marie Line Alberi-Morel; Carine Balageas; Vinod Kumar
Original assignee: Alcatel Lucent SAS
Current assignee: Provenance Asset Group LLC
Priority date: 2007-10-22
Filing date: 2008-10-20
Publication date: 2010-08-11
Also published as: FR2922710B1; US8934469B2; JP2011501598A; CN101878647B; WO2009053663A3; CN101878647A; US20120093144A1; WO2009053663A2; FR2922710A1

Abstract

A method is dedicated to the transmission, via a transmission infrastructure (RC), using waves and with an access procedure relying on at least time division multiplexing, of contents of at least one channel, each of which is arranged in a base data layer and at least one layer of improvement data associated respectively with different transmission timeslots, and which are sliced into portions transmitted during the timeslots respectively associated with their layers. This method comprises i) the insertion at a chosen location of each portion to be transmitted of a base data layer, at the level of a chosen network layer, of at least one learning sequence processed according to a configuration scheme identical to that used to process said improvement data layer, and ii) on receipt of a portion of a base data layer of a content in a terminal (TC), the extraction of the learning sequence inserted at the level of a chosen network layer, then the estimation of the quality of reception on the basis of this extracted learning sequence, and the authorization to use the portion of the improvement data layer of the content when the estimated quality is greater than a chosen threshold.

Description

OPTIMIZED TRANSMISSION METHOD, TO MOBILE TERMINALS AND VIA RADIO INFRASTRUCTURE WITH TDM / TDMA / OFDMA TYPE ACCESS METHOD, LAYERED CONTENT, AND PROCESSING DEVICE THEREOF

The invention relates to the transmission of so-called "layered" content by means of wavelength transmission infrastructures and access method based on a multiplexing at least temporal. Here, the term "multimedia layered content" means a set of data arranged in scalability layers, typically comprising a so-called base layer (in English "base layer") and one or more so-called improvement layers (in English "enhancement layer"). ") Complementary to the base layer. The base layer includes all the data of a multimedia content that will allow a receiving equipment to reproduce this multimedia content with the lowest quality (or definition or resolution). Each enhancement layer includes another set of data of said multimedia content which will enable said communication terminal to supplement the base layer data set to reproduce the multimedia content with improved quality (or definition or resolution). According to some layer encoding methods the different layers are hierarchically related to each other, so that the nth improvement layer of multimedia content can be used only if the base layer and the n-1 layers previous enhancements of this multimedia content (associated with lower qualities (or definitions or resolutions)) were exploited. According to other methods, only a hierarchy between the base layer and the improvement layer (s) exists, so that the n-th improvement layer of a multimedia content improves the quality of the content ( for example increasing the number of pixels of an image, increasing the image quality and / or increasing the image refresh rate) as decoded from the base layer without the need to have previously exploited one of the previous n-1 layers. A content Multimedia thus encoded in layers may for example be a television or radio program, an audio file or a video.

Furthermore, the term "wavelength transmission infrastructure and access method based on at least a time-division multiplexing" is understood to mean any infrastructure in which the transmission of contents is done by waves in a monodirectional manner or bidirectional using access method (s) based on TDM or TDMA (Time Division Multiplexing or Time Division Multiple Access) or TDMA / OFDM (TDM / Orthogonal Frequency Division Multiplexing) , or based on an OFDMA (Orthogonal Frequency Division Multiple Access) type of time and frequency multiplexing. Therefore,! This may be a radio communication network as well as a broadcast network.

It is recalled that a TDM type access method consists of time-division multiplexing of services, and thus several users can have access to the same service at the same time, whereas a TDMA access method consists of a temporal multiplexing of content intended for different users and may each correspond to one or more services. In addition, "broadcast network" here refers to any type of TDM, TDMA or OFDMA terrestrial and / or satellite broadcasting infrastructure capable of transmitting content along one channel. monodirectional downlink (or go) to mobile (or cellular) or portable communication terminals.

In addition, the term "communication network" here refers to any type of TDMA communication infrastructure that is bidirectional, broadband, and wireless, in particular capable of broadcasting content via waves to terminals, in "broadcast" mode (broadcasting ) and / or "multicast" (point-to-point) and / or "unicast" (point-to-point).

Consequently, a TDM, TDMA or TDM / OFDM infrastructure may be a wireless network such as a TDM-type multiplexing broadcast network (for example, a terrestrial network of the DVB-H type (for example "Digital Video Broadcasting - Handhelds" - a mobile TV network), a TDM (eg DVB-S2 type) or TDMA (eg DVB-RCS) type of multiplexing satellite network, or a hybrid network, that is to say both satellite and terrestrial, multiplexing type TDM (as for example a DVB-SH type network (or DVB-SSP) (satellite links with terrestrial relay))), a cellular network ( TDMA-type multiplexing (such as for example a GSM / EDGE type network), a wireless local area network or WLAN (for example a Wi-Fi type network), or a metropolitan network or MAN (for example "Metropolitan Area Network" - as for example a WiMAX type network (in so-called single-carrier and multi-carrier modulation modes)).

Finally, the term "communication terminal" here refers to any mobile (or portable or cellular) communication equipment capable of receiving at least layered contents of a TDM / TD access method transmission infrastructure. TDMA / OFDMA. Therefore, it may for example be a mobile phone (or cell), a laptop, a digital personal assistant (PDA), a layered content receiver (eg a decoder , a residential gateway (or "residential gateway") or an STB ("Set-Top Box")), provided it is equipped with communication means, radio (or satellite), capable of receiving layered content .

As is known to those skilled in the art, in certain wave transmission infrastructures and access method TDM, TDMA or OFDMA it is possible to attribute to the various complementary layers (basic and improvement) , which constitute a content of a channel or an IP stream, different time slices of transmission (or "time slices"), and to cut these layers in portions in order to transmit them (generally in bursts (or "bursts") »)) To (communication) terminals during the time slots respectively associated with them. Here we mean by "channel" a television or radio channel, or a video broadcaster.

When the user of a (communication) terminal receives the contents of a given channel (or IP stream), he selects this channel with his terminal, and it only activates its receiver during the time slots that have been assigned to the different layers of the selected channel. During the time slots allocated to the other unselected channels, the receiver is placed in idle mode, thus saving CPU capacity and energy (which is advantageous in the case of a mobile terminal or portable equipped with a battery).

Most TDM, TDMA or OFDMA (radio) access method infrastructures include a radio access network called "non-uniform radio coverage", ie in which the quality of reception (or quality of reception) is defined. link (or link) radio varies depending on the position within its radio coverage area. It is recalled that the quality of reception (or quality of the radio link) is quantifiable by means of parameters such as for example the CIR (for "Carrier to Interference Ratio" - ratio between the power of the received signal and the sum of the powers of the internal noise receiver and interference noise caused by the environment) or BER ("Bit Error Rate") or the PER (for "Packet Error Rate") .

In the presence of such discontinuities in reception quality, the radio coverage area includes sub-areas with different reception quality levels. Therefore, users, whose terminals are located in a sub-area with good radio conditions, can receive the data packets of all the complementary layers of the content of the selected channel, during the time slots associated with the layers of this channel, and thus have contents of optimal quality. On the other hand, the users, whose terminals benefit from bad radio conditions, can only receive the data packets of the base layer of the content of the selected channel, and thus have contents of inferior quality. This results from the fact that the transmission of the data packets of the enhancement layers is

(much) more radio-sensitive than base-layer data packets.

In the presence of an allocation of time slots of different transmission to the different complementary layers of a content of a selected channel, when a terminal benefits from bad radio conditions, and therefore it can only correctly receive the data packets of the base layer of the contents of a selected channel, it continues to be activated during each time slice that is associated with one of the selected channel content enhancement data layers even though it can not properly receive the packets. In this situation, the terminal can self-configure, but it consumes unnecessarily the processing capacity (CPU) and energy, which is penalizing when equipped with a battery.

The object of the invention is therefore to remedy the aforementioned drawback in a TDM, TDMA or OFDMA access and TDMA access method comprising a non-uniform radio coverage radio access network. It proposes for this purpose a method, dedicated to the transmission, via a wave transmission infrastructure and access method based on a multiplexing at least temporal content of at least one channel, each arranged in one base data layer and at least one enhancement data layer respectively associated with different transmission time slots, and cut into portions transmitted during time slots respectively associated with their layers.

This method comprises: i) inserting at a chosen location each portion to be transmitted from a base data layer, at a selected network layer, of at least one learning sequence processed according to a schema of same configuration as that used to process the enhancement data layer, and ii) receiving a portion of a base data layer of a content, extracting the inserted learning sequence at the level of a selected network layer, then the estimation of the reception quality from this extracted training sequence, and the authorization to use the next portion of the content enhancement data layer when the estimated quality is greater than a chosen threshold. The term "configuration scheme" is used here to mean both the protection schemes (coding, interleaving, and the like) that can be implemented in at least one network layer, that the formatting schemes (modulation and the like), or as your transport schemes. Therefore, "pattern-based processing" means any processing or mechanism implemented in the network to "configure" a signa! transmitted.

The method according to the invention may comprise other characteristics that can be taken separately or in combination, and in particular: at ii) the reception quality can be estimated by determining the value taken by a quality parameter relating to the sequence of extracted learning, at a chosen network layer, and this value can be compared to the threshold chosen to determine whether to allow the use of the next portion of the content enhancement data layer; This quality parameter may for example be chosen from (at least) the signal-to-noise ratio (SNR), the CIR ("Carrier to interference interference ratio"), the bit error rate received (BER), the frame rate received error (FER), received signal strength, CRC (Cyclic Redundancy Check), received erroneous packet rate (PER), and video perception quality; - in the presence of content improvement data layers processed according to different configuration diagrams, i) at least one selected location of each portion to be transmitted from the base data layer may be inserted at the level of a chosen network layer, learning sequences respectively processed according to the configuration schemes used to process the content enhancement data layers, and ii) receiving a portion of a base data layer of that content, the inserted training sequences can be extracted at a chosen network layer, then the respective reception qualities of the improvement data layers can be estimated from the extracted training sequences, and the use of of the next portion of a content enhancement data layer when the corresponding estimated quality is greater than a chosen threshold associated with that layer of improvement data; alternatively, in the presence of several layers of data for improving a content processed according to the same configuration diagram, it is possible to estimate the quality of reception from the extracted training sequence, and the use can be authorized the next portion of each layer of content enhancement data when the estimated quality is greater than a chosen threshold;

the training sequence can be inserted at the level of a network layer which is chosen from the physical layer, the MAC layer, the transport layer and the application layer. For example, one can insert the learning sequence at the level of the physical layer;

the chosen place of insertion of a training sequence may for example be the end of a portion of a basic data layer.

The invention also proposes a processing device, for a transmission infrastructure, by means of a wavelength and with an access method based on at least one time multiplexing, of contents of at least one channel, each arranged in a layer of basic data and at least one improvement data layer respectively associated with different transmission time slots, and intended to be divided into portions to be transmitted during time slots respectively associated with their layers.

This processing device is responsible, in the event of reception of portions of basic data layers and improvement of a content to be transmitted, of inserting at a chosen location of each portion of the basic data layer, at the level of a chosen network layer, at least one training sequence processed according to a pattern identical to that used to process the improvement data layer.

The device according to the invention may comprise other characteristics that can be taken separately or in combination, and in particular:

it can be loaded, in case of reception of a content comprising layers of improvement data processed according to different configuration diagrams, to insert in at least one selected location of each portion to be transmitted of the data layer of base, at the level of a chosen network layer, the learning sequences processed respectively according to the configuration schemes used to process the content enhancement data layers;

it can be instructed to insert the training sequence at a network layer which is chosen from the physical layer, the MAC layer, the transport layer and the application layer;

it may be instructed to insert the training sequence at a location which is located at the end of the portion of a basic data layer.

The invention also proposes a communication terminal comprising; a reader capable of using the contents of at least one channel, and a receiver adapted to receive from a transmission infrastructure, by means of waves and with an access method based on at least a time-division multiplexing, contents of at least one channel in the form of portions of a base data layer and at least one enhancement data layer respectively associated with different transmission time slots, and responsible for decoding the received content portions so as to to reconstitute each content to feed the reader,

activation means charged, in case of selection of a channel, of activating the receiver during each time slot associated with each basic data layer of a content of the selected channel, and

processing means responsible for extracting from each portion of the basic data layer of the content (received by the receiver), at the level of a chosen network layer, an inserted learning sequence, processed according to a configuration diagram identical to that used to process the enhancement data layer, then to estimate the reception quality from this extracted training sequence, and to instruct the activation means to activate the receiver during the next slice that is associated with the content enhancement data layer of the selected channel when the estimated quality is greater than a chosen threshold, so that it uses the next portion of the enhancement data layer received in addition to the portion of the base data layer to reconstruct their content. The terminal according to the invention may comprise other characteristics which may be taken separately or in combination, and in particular:

its processing means may be responsible for estimating the quality of reception by determining the value taken by a quality parameter relating to the extracted learning sequence, at a chosen network layer, and comparing this value with the threshold selected to determine whether they can allow the activation means to activate the receiver during the next time slot that is associated with the content enhancement data layer of the selected channel;

its processing means can be loaded, in the presence of content improvement data layers processed according to different configuration diagrams, to extract from each portion of the basic data layer of a content, at the level of of a chosen network layer, inserted learning sequences, respectively processed according to the configuration schemes used to process the content enhancement data layers, and then to estimate the respective reception qualities of the enhancement data layers. from the extracted training sequences, and instructing the activation means to activate the receiver during the next time slot that is associated with a content enhancement data layer of the selected channel when the corresponding estimated quality is greater than a chosen threshold, so that it uses the next portion received from this enhancement data layer in addition to e the portion of the basic data layer to reconstruct their content;

alternatively, its processing means can be loaded, in the presence of several layers of content improvement data processed according to the same configuration diagram, to estimate the quality of reception from the extracted training sequence. , and instructing the activating means to activate the receiver during the next time slot associated with each content improvement data layer of the selected channel when the estimated quality is greater than an associated selected threshold, so that uses the next received portion of each enhancement data layer to complement the portion of the base data layer to reconstruct their content. The invention is particularly well suited, although not exclusively, to networks of DVB-H, DVB-SH (or DVB-SSP) and WiMAX type.

Other features and advantages of the invention will appear on examining the detailed description below, and the attached drawings, in which:

FIG. 1 very schematically and functionally illustrates a TDM transmission infrastructure to which is connected an exemplary embodiment of a communication terminal according to the invention and a transmission equipment provided with a processing device according to the invention. , and

FIG. 2 is a timing diagram (t) representing an example of triplet of time slots associated with three complementary layers of contents of two different channels.

The attached drawings may not only serve to complete the invention, but also contribute to its definition, if any.

The object of the invention is to propose a mode of transmission of layered contents, via a wave transmission and access method infrastructure based on a TDM, TDMA or OFDMA type multiplexing and comprising a network of access to non-uniform coverage area, making it possible to limit, by self-configuration, the processing capacity used and the power consumption by mobile (or mobile) communication terminals when they are located in a sub-zone that does not benefit from good radio conditions.

In what follows, it is considered as a non-limiting example that the transmission infrastructure is a radio communication network type DVB-H (for "Digital Video Broadcasting - Handhelds" - mobile TV) with access method based on a TDM type multiplexing. But, the invention is not limited to this type of transmission infrastructure. It concerns in fact any type of infrastructure capable of transmitting over-the-air (possibly multimedia), monodirectional or bidirectional, by means of an access method based on TDM, TDMA or OFDMA type multiplexing. whether it is a unidirectional broadcast network (terrestrial and / or satellite) or a bidirectional, broadband, non-wired communication network. Therefore it may also be a GSM / EDGE cellular (or mobile) network, a wireless local area network or WLAN (such as a Wi-Fi type network), a metropolitan network. or MAN (such as for example a WiMAX type network (in so-called single-carrier and multi-carrier modulation modes)), of a terrestrial network implementing a technology derived from satellite technology (for example DVB-S, DVB-S2 or DVB-RCS), or a hybrid network, such as a DVB-SH (or DVB-SSP) type network, or an access method infrastructure based on a multiplexing type OFDMA.

Furthermore, it is considered in the following, by way of non-limiting example, that the communication terminals (TC) are mobile phones (or cellular) or digital personal assistants (or PDAs). However, the invention is not limited to this type of radio communication terminal. It relates in fact to any mobile communication equipment (or mobile or cellular) capable at least to receive layered content by wave via a TDM or TDMA or OFDMA transmission infrastructure. Therefore, it may also be a laptop, a layered multimedia content receiver (eg a decoder, a residential gateway (or "residential gateway") or a STB ("Set-Top Box") )), provided that it is equipped with means of communication by wave (radio or satellite) suitable at least for the reception of layered contents.

In addition, it is considered in the following, by way of non-limiting example, that the layered content broadcast to the terminals (TC) are multimedia content such as videos. But, the invention is not limited to this type of layered content. It concerns indeed any type of layered content, including television or radio programs and audio content. As is schematically illustrated in FIG. 1, the implementation of the invention requires the presence of at least one ET layer transmission equipment, of at least one processing device D, of at least one (communication) terminal TC, and at least TDM or TDMA or OFDMA RC transmission (wavelength) infrastructure.

In what follows, it is considered as a nonlimiting example that the contents (here videos) are arranged in three complementary layers, one being a base layer Bi (i = 1 or 2 denoting one channel), and the other two being enhancement layers Cij (j = 1 or 2) intended to improve the quality (or definition or resolution) offered by the base layer Bi when at least one of them is combined with the latter (Bi). But, the invention is not limited to this number (3) of complementary layers. This number can indeed be as large as one wants since it is at least equal to two (2).

The transmission equipment AND is for example an access platform (or "access gateway") located in the network RC, and more precisely upstream of an input of its radio access network. It intervenes each time it receives a stream, here a layered video content, possibly in the form of IP packets. The layered content stream can have any origin. In the nonlimiting example illustrated in FIG. 1, the video content in layers is provided by a server (or a service platform) SC.

It is recalled that content (in layers) must be transmitted as part of a transmission session, possibly shared, to a set of at least one user (or even to all users) present in a coverage area of the RC network radio access network. Therefore, at the beginning of a session, and for its duration, the radio access network provides each TC terminal, which is within its coverage area and participating in this session, with a broadcast link (or "Broadcast") or point-to-multipoint (or "multicast") and / or point-to-point link (or "unicast") content transfer, for example, the server (content) SC encapsulates the data layers of each content in RTP / UDP / IP and transmits them to the transmission equipment AND in the form of a data packet stream conforming to the RTP transport protocol (for "Real-time" Transmission Protocol ") that multiplexes them.

For example, the transmission equipment AND receives video streams with three layers (complementary) Bi and Cij associated with two different channels CAi (i = 1 or 2). The invention is not limited to these numbers of layers and channels. As indicated above, the number of complementary layers may indeed be as large as desired (within the limits of the transmission capacity of the RC network). Furthermore, the invention applies as soon as the contents of at least one channel must be transmitted (transported). The transmission equipment ET here comprises (by way of non-limiting example) a loaded separator EN, when it receives a stream of data packets of a layered content, to separate (demultiplex) the packets according to their layers of belonging. Each layer Bi and Cij of a content of a channel CAi is thus "cut into portions" (for example into IP packets), and the separator EN adjusts to each portion a tag (or "tag") representative of the layer. which she belongs.

It is important to note that each layer Bi or Cij of a content of a channel CAi is processed according to a configuration scheme (for example an encoding and modulation scheme when the processing is performed at the level of the physical layer (PHY )). This processing is done either on each packet (header and payload (or "payload")) or only on the header of each packet. Generally, the configuration scheme that protects the basic data layer Bi is not the same as that protecting the enhancement data layer (s) Cij of the same content. This is called "unequal treatment of data". Moreover, the improvement data layers Cij are generally processed according to the same configuration scheme. But, this is not mandatory.

The processing of a layer Bi or Cij is done at the level of a network layer (of the OSI model) chosen from the physical layer PHY, the access control layer of the media (network) or MAC ("Media Access Control" ), the transport layer and the application layer. Therefore, the equipment or the element in which the processing according to a configuration scheme is done depends on the layer at which this processing is done. For example. if the insertion is done at the level of the physical layer (PHY), according to a coding and modulation scheme, or of the MAC layer, it is carried out by a base station SB, and if it is done at the level of the IP layer or transport, then it is performed in the equipment or item concerned with the treatment of this layer.

Each layer Bi and Cij of a content of a channel CAi is associated with a transmission time slice Tik (k denotes the layers, here k = 1 to 3) dedicated, and therefore each portion of a layer Bi or Cij must be transmitted during the Tik time slot associated with it. In other words, Ni time slots Tik are assigned to each channel CAi, Ni being here the number of complementary layers Bi and Cij constituting the contents of a channel CAi. It will be understood that the number Ni of complementary layers may possibly vary from one channel to another, but it may also be the same for all CAi channels. The processing device D is responsible for inserting at a chosen location of each portion of the basic data layer Bi of a content of a channel CAi, at a chosen network layer, a training sequence SA predetermined which is processed according to a configuration pattern identical to that used to process at least one of the improvement data layers Cij.

This insertion can be done at the level of a network layer (OSI model) chosen from the physical layer (PHY), the MAC layer, the transport layer and the application layer. It will thus be understood that the processing device D can be implanted in different locations according to the network layer at which it must perform its insertion. Thus, if the insertion is at the level of the application layer, the device D can be implemented in a service platform connected to the content server SC or in the latter. If the insertion is at the level of the transport layer, the processing device D can be implanted in the core network of the RC network. If the insertion is done at the level of the PHY or MAC layer, the processing device D can be implanted in a base station of a radio access network of the network RC, as is the case in the example non-limiting example shown in Figure 1. It will be noted that the processing device D uses the labels that have been attached by the separator EN to detect the portions of the base layer Bi in which it must insert a learning sequence SA. Note also that it is not necessary that the insertion of a learning sequence SA is done in a network layer identical to that where the protection is by a configuration diagram. The final extraction is facilitated, however, when the insertion of a learning sequence SA is done in the same network layer as that where the protection is by a configuration diagram. It will also be noted that the insertion of a training sequence

SA can be done anywhere in a portion of a basic data layer Bi. But, it is advantageous to do it at the end of the portion because the symbols contained in this place are those which are transmitted last and therefore which are temporally the closest to the symbols contained in the portion of a layer of Cij improvement data. next, and therefore the most representative of the radio transmission conditions.

It will also be noted that when the improvement data layers Cij of a content are processed according to different configuration diagrams, the processing device D may be instructed to insert at least one selected location of each portion of the layer of basic data Bi of this same content, at the level of the same network layer chosen, learning sequences SAj respectively processed according to the configuration schemes that protect these layers of improvement data Cij. Once the processing device D has proceeded to one (or more) insertion (s) of learning sequence (s) SA in a portion of the basic data layer Bi of a content, it transmits this portion to RC network for transmission to the TC terminals during time slots Tik which are respectively associated with said layers Bi and Cij.

FIG. 2 schematically shows an exemplary time diagram (i) of transmission by the network RC of the portions of the three complementary layers Bi (i = 1 or 2) and Cij (j = 1 or 2) of two video channels CAi during time slots Tik which are respectively associated with said complementary layers Bi and Cij. More precisely :

a portion of the base layer B1 of a video of the first channel CA 1 is transmitted (for example in a burst) during the first time slot Ti 1 of the first channel CA 1,

a portion of the first enhancement layer C11 of this same video of the first channel CA1 is transmitted (for example in a burst) during the second time slot Ti 2 of the first channel CA 1, a portion of the second enhancement layer C12 of this same video of the first channel CA 1 is transmitted (for example in a burst) during the third time slot T13 of the first channel CA1,

a portion of the base layer B2 of a video of the second channel CA2 is transmitted (for example in a burst) during the first time slot T21 of the second channel CA2,

a portion of the first enhancement layer C21 of this same video of the second channel CA2 is transmitted (for example in a burst) during the second time slot T22 of the second channel CA2, a portion of the second layer C22 improvement of the same video of the second channel CA2 is transmitted (for example in a burst (or burst)) during the third time slot T23 of the second channel CA2,

another portion of the base layer B1 of a video (possibly the same as that of the preceding portion) of the first channel CA 1 is transmitted (for example in a burst) during another first time slot Ti 1 of the first channel CA 1,

another portion of the improvement layer C12 of this same video of the first channel CA1 is transmitted (for example in a burst) during another second time slot T12 of the first channel

CA1,

another portion of the second C12 improvement layer of this same video of the first channel CA1 is transmitted (for example in a burst) during another third time slot T13 of the first channel CA1, and so on.

It is important to note that the temporal slice (s) associated with a CAi channel (and more precisely with the complementary Bi and Cij layers of its contents) are not necessarily contiguous (as is the case in the non-limiting example of timing diagram illustrated in Figure 2). The different complementary layers Bi and Cij of the different channels CAi can indeed be interlaced. It is also important to note that the bursts transmission period which may contain the portions (or packets) of complementary layers (Bi and Cij) is not necessarily the same for all the complementary layers Bi and Cij and for all the channels CA i.

In order to be able to receive, from the network RC (and possibly transmit) layered contents which have been inserted into a learning sequence (s) SA, the (communication) terminals TC comprise at least:

a receiver R coupled to an antenna AN and responsible for receiving, from the RC network, when it is activated, (bursts of) portions (or packets) of base data layer Bi and data layer (s) of improvement Cij of contents of at least one channel CAi and respectively associated with different transmission time slots Tik, and deliver complementary data packets Bi and Cij. It contains in particular the stages dealing with the different network layers (PHY MAC, IP, transport),

a possible buffer (or "buffer") BF, possibly forming part of the receiver R, and responsible for temporarily storing the packets delivered by the receiver R, then delivering these packets stored on an output, - a content reader LC loaded to use the packets of the complementary layers delivered (possibly by the buffer BF) in order to display and / or diffuse the contents which they constitute and

an AF display such as a screen, responsible for displaying the images of the contents delivered by the LC content reader, and / or at least one HP speaker, responsible for broadcasting the sounds of the contents delivered by the LC content reader.

According to the invention, each termina! TC also includes an activation module MA and an processing module MT.

The activation module MA is loaded, when a channel CAi has been selected within its terminal TC, to activate the receiver R during each time slot Ti1 (of the same index i) that has been associated with the data layer. basic Bi contents of the selected channel CAi. Here, the term "activate" means allowing the power supply and therefore the operation of the receiver R during a time interval at least equal to the duration of a time slot Ti 1.

In order to be able to perform these activations at precise times, the activation module MA must not only use information representative of the temporal positions of the time slots Tik and of their association with the complementary layers Bi and Cij of the contents of the different channels CAi, but also be substantially synchronized with respect to a clock of the RC network. This synchronization can for example be ensured by periodic transmission to the terminals TC of a signaling message comprising synchronization information. Furthermore, the time and association information is transmitted to the TC terminals, via the network RC, in signaling messages. For example, a signaling message may contain the start time of a first slot T11, the duration of the time interval between the beginnings of two successive time slots Tik and T (i + 1) k or Ti (k + 1), ie the number of time slots Tik and the correspondences between the time slots Tik and the associated complementary layers.

It will be noted that the constitution of each learning sequence SA, the location chosen for the insertion of the learning sequence (s) SA and the network layer at which this insertion takes place can be indicated at each TC terminal by means of a signaling message. Alternatively, each TC terminal may be preconfigured to know where the sequence (s) is (are) systematically inserted. These signaling messages are for example generated by the transmission equipment ET or by the device D.

By way of example and with reference to the nonlimiting example illustrated in FIG. 2, if the first channel CA1 has been selected, the activation module MA will activate the receiver R just before the beginning of each first time slot T11. of the first channel CA 1 and deactivate the receiver R just after the end of each first time slot TH of the first channel CA 1.

The processing module MT is first responsible for extracting from each portion of the basic data layer Bi a content received by the receiver R during the corresponding time slot T1, at a network layer. chosen, each SA training sequence previously inserted by the processing device D.

It is important to note that the network layer, at which the processing module MT performs the extraction of a learning sequence SA, is not necessarily identical to that at which this training sequence SA has been inserted. But, for a question of complexity, it is preferable that insertion and extraction occur at the same network layer, for example the physical layer (PHY). The processing module MT is also responsible for estimating the current reception quality of its terminal TC from the extracted training sequence, in order to determine whether the packages of the improvement layers Cij have a high probability of being correctly received. To do this, it compares the estimated reception quality with a chosen threshold and when the estimated quality is greater than a chosen threshold, it authorizes the use of the portion of at least one improvement data layer Cij of the content considered. . It will be noted that, in case of extraction of several learning sequences SAj associated with the various improvement layers Cij of a content, the processing module MT estimates the reception qualities of its terminal TC from the different sequences of SAj learning extracted, to determine whether the packages of at least one of the improvement layers Cij have a high probability of being correctly received.

For example, the processing module MT estimates a quality of receiving current by determining the value that takes a quality parameter (or metric) that is relative to the learning sequence SA that is extracted at a chosen network layer, then comparing this value to a chosen threshold. The quality parameter (or metric) is for example chosen from at least the signal-to-noise ratio or SNR ("signal to noise ratio"), the ratio between the power of the received signal and the sum of the powers of the internal noise of the receiver and interference noise caused by the environment or CIR (for "Carrier to Interference Ratio"), the bit error rate received or BER ("Bit Error Rate"), the rate of received erroneous frames or FER (" Frame Error Rate "), the received signal strength, the CRC (" Cyclic Redundancy Check "), the rate of received erroneous packets or PER (" Packet Error Rate "), and the quality of video perception. In fact, the quality parameter that is chosen depends on the network layer at which the processing module MT performs the extraction of a learning sequence SA.

For example, if the extraction is done at the level of the MAC layer can be used for example CRC, BER, or FER. For example, if the extraction is done at the level of the physical layer (PHY), it is possible for example to use the SNR, the ClR, the BER or the power of the received signal. For example, if the extraction is at the level of the transport layer or the application layer can for example use the CRC or video perception quality.

Any technique known to those skilled in the art, intended to determine the value taken by a quality parameter (or metric) from data received by a TC terminal can be used.

The processing module MT compares the value of the quality parameter (or metric) chosen at the chosen threshold. If the estimated reception quality is represented by a parameter whose value must be as large as possible (for example the received power or the CIR), then the processing module MT authorizes the activation module MA to activate the receiver R during the next Tik temporal slice (s) associated with the enhancement data layer (s) Cij of the content at the selected channel when the value is greater than the selected thresholdI. He considers effect that the next packets of at least one of the improvement layers Cij have a high probability of being correctly received and therefore sends activation instructions to the activation module MA. Otherwise, it does not send an activation instruction to the activation module MA. If the estimated reception quality is represented by a parameter whose value must be as small as possible (for example the BER), then the processing module MT authorizes the activation module MA to activate the receiver R during (the) next Tik temporal slice (s) associated with the enhancement data layer (s) Cij of the selected channel content, when the value is below the chosen threshold. It considers that the next packets of at least one of the improvement layers Cij have a high probability of being correctly received and therefore sends activation instructions to the activation module MA. Otherwise, it does not send an activation instruction to the activation module MA.

When the activation module MA receives activation instructions designating one or more improvement data layers Cij, it activates the receiver R during each next time slot Tik which is associated with each designated improvement data layer. By way of example and with reference to the nonlimiting example illustrated in FIG. 2, if the second channel CA2 has been selected and the quality of reception is considered sufficiently good following the reception of the portion of the data layer B2 base during the first time slot T21 of the second channel CA2, the activation module MA will activate the receiver R just before the start of the second time slot T22 of the second channel CA2, which follows its first time slot T21, and disable the receiver R just after the end of this second time slot T22 of the second channel CA2, then it will activate the receiver R just before the start of the third time slot T23 of the second channel CA2 following the second time slot T22, and disable the receiver R just after the end of this third time slot T23 of the second channel CA2. Thus, the receiver R can receive and process the portions of the layer (s) of improvement data Cij that it receives during the next associated time slot (s) Tik (s). More specifically, the receiver R can decode the received portions and reconstruct the decoded data packets belonging to the basic data layer Bi and the layer (s) of improvement data Cij in order to progressively reconstitute their content in the quality offered by their combination.

Note that in a variant when a content is defined by a basic data layer Bi and several improvement data layers Cij processed according to the same configuration diagram, the processing module MT extracts from each portion of the layer of data. basic data Bi of this content, at the level of a chosen network layer, the inserted training sequence SAj, which is processed according to the configuration scheme. Then, it estimates a reception quality for all the improvement data layers Cij from the extracted learning sequence SAj. It can then compare the estimated reception quality with several chosen thresholds respectively associated with the different layers of improvement data Cij, and order the activation module MA to activate the receiver R during the next time slot Tik which is associated with a improvement data layer Cij of the content of the selected channel CAi when the estimated reception quality is greater than the chosen threshold associated with this layer Cij, in order to allow the receiver R to use the next portion received from this data layer of improvement Cij in addition to the portion of the basic data layer Bi, in order to reconstitute their content. It will be understood that the quality of reception can be estimated to be greater than the threshold associated with one of the improvement data layers Cij but lower than the threshold associated with another layer of improvement data Cij.

It will also be noted that when a content is defined by a basic data layer Bi and several improvement data layers Cij processed according to different configuration diagrams, the processing module MT extracts from each portion of the data layer of Bi base of this content, at a chosen network layer, all inserted learning sequences SAj, which are processed respectively according to the different configuration schemes. Then, he considers the reception qualities respective ones for the different enhancement data layers Ci) from the corresponding extracted training sequences SAj, fi can then instruct the activation module MA to activate the receiver R during the next time slot T ik which is associated with a improvement data layer Cij of the content to the selected channel CAi when its corresponding estimated reception quality is greater than a chosen threshold, in order to allow the receiver R to use the next portion received from this improvement data layer Cij in complement the portion of the basic data layer Bi to reconstruct their content. It will be understood that the estimated reception quality corresponding to one of the improvement data layers Cij can be estimated to be greater than an associated chosen threshold, while that of another improvement data layer Cij can be estimated to be less than a (other) chosen associated threshold. Likewise, the estimated reception qualities corresponding to the different layers of improvement data Cij can all be estimated to be greater than their respective thresholds.

Since the receiver R is activated only to receive the portions of the basic data layer Bi and when the packets of the improvement layers Cij have a high probability of being correctly received, the processing capacity can be saved. and energy at its TC terminal.

The processing device D and / or the activation module MA and / or the processing module MT may be implemented in the form of electronic circuits, software (or computer) modules, or a combination of circuits and software . it is important to note that the invention can also be considered in terms of a content transmission method that can be implemented in particular by means of the radio network RC, the processing device D, the transmission equipment ET and TC communication terminal presented above. The functionalities offered by the implementation of the method according to the invention being identical to those offered by the network elements and equipment (in particular the processing device D and the communication terminal TC) presented above, only the The main feature combination offered by the method is presented below.

This content transmission method comprises: i) inserting at a chosen location of each portion to be transmitted from a base data layer Bi, at a chosen network layer, at least one training sequence SA processed according to a pattern identical to that used to process at least one of the improvement data layers Cij, and ii) receiving a portion of a basic data layer Bi from a content, extracting the inserted SA training sequence at a selected network layer, then estimating the reception quality from that extracted SA training sequence, and allowing the use of the the improvement data layer Cij of the content when the estimated quality is greater than a chosen threshold. The invention is not limited to the embodiments of processing device, communication terminal and transmission method described above, only by way of example, but it encompasses all the variants that can be envisaged by the man of art within the scope of the claims below.

Claims

A method of transmitting, via a transmission infrastructure (RC), over the airwaves and access method based on at least one multiplexing of contents of at least one channel, each arranged in a data layer of at least one channel. base and at least one enhancement data layer respectively associated with different transmission time slots, and divided into transmitted portions during time slots respectively associated with their layers, said method comprising i) insertion at a chosen location of each portion transmitting from a base data layer, at a chosen network layer, at least one training sequence processed according to a configuration pattern identical to that used to process said improvement data layer, and ii) upon receiving a portion of a base data layer of a content, extracting said inserted training sequence at a layer chosen network, then an estimate of the reception quality from this extracted learning sequence, and an authorization to use the next portion of said enhancement data layer of said content when the estimated quality is greater than a chosen threshold .

2. Method according to claim 1, characterized in that ii) the quality of reception is estimated by determining the value taken by a quality parameter relative to the extracted training sequence, at a chosen network layer, and comparing said value with said selected threshold to determine whether to allow the use of the next portion of said enhancement data layer of said content.

3. Method according to claim 2, characterized in that said quality parameter is chosen from a group comprising at least the signal-to-noise ratio, the CiR, the bit error rate received (BER), the rate of errored frames. received (FER), the received signal strength, the CRC, the received errored packet rate (PER) and the video perception quality.

4. Method according to one of claims 1 to 3, characterized in that in the presence of layers of data for improving a processed content according to different configuration diagrams, i) at least one selected location of each portion to be transmitted from the base data layer, at the level of a chosen network layer, is inserted into the training sequences respectively processed according to the schemas of FIG. configuration used to process said data enhancement layers of said content, and ii) upon receiving a portion of a base data layer of that content, extracting said inserted training sequences at a network layer chosen, then the respective reception qualities of said improvement data layers are estimated from said extracted training sequences, and the use of the next portion of a data enhancement layer of said content is allowed when the quality The corresponding estimate is greater than a selected threshold associated with this enhancement data layer.

5. Method according to one of claims 1 to 3, characterized in that in the presence of several layers of content improvement data processed according to the same configuration diagram, the quality of reception is estimated from Ia. extracted training sequence, and authorizing the use of the next portion of each layer of improvement data of said content when the estimated quality is greater than a chosen threshold.

6. Method according to one of claims 1 to 5, characterized in that said training sequence is inserted at a selected network layer in a group comprising the physical layer, the MAC layer, the transport layer and the application layer.

7. Method according to claim 6, characterized in that said training sequence is inserted at the level of the physical layer.

8. Method according to one of claims 1 to 7, characterized in that said chosen location of insertion of a training sequence is the end of the portion of a basic data layer.

9. Processing device (D), for a transmission infrastructure (RC), wavelength and access method based on υn at least one time multiplexing contents of at least one channel each arranged in a layer of basic data and at the m oins a layer of improvement data respectively associated with different transmission time slots, and intended to be divided into portions to be transmitted during the time slots respectively associated with their layers, said device (D) being arranged, in case of receiving portions of layers of basic data and improvement of a content to be transmitted, for inserting at a chosen location of each portion of said base data layer, at a chosen network layer, at least one training sequence processed according to a configuration scheme identical to that used to process said improvement data layer.

10. Device according to claim 9, further arranged for, in the case of receiving a content comprising improvement data layers processed according to different configuration diagrams, inserting in at least one selected location of each portion to be transmitted from the basic data layer, at a chosen network layer, the training sequences respectively processed according to the configuration diagrams used to process said data improvement layers of said content.

Apparatus according to one of claims 9 and 10, further arranged for inserting said training sequence at a selected network layer into a group comprising the physical layer, the MAC layer, the transport layer and the layer. application.

The device of claim 11, further arranged to insert said training sequence at the physical layer.

13. Device according to one of claims 9 to 12, further arranged to insert said training sequence at a location at the end of the portion of a basic data layer.

14. Communication terminal (TC) comprising i) a reader (LC) adapted to use contents of at least one channel and a receiver (R) adapted to receive a transmission infrastructure (RC), by way of and access method based on at least one time multiplexing, contents of at least one channel in the form of portions of a base data layer and at least one layer of associated enhancement data respectively to transmission time slots different, and arranged to decode said received content portions to reconstruct each content intended for said reader (LC), ii) activation means (AM) arranged, in case of selection of a channel, to activate the receiver (R ) during each time slot associated with each basic data layer of a content of the selected channel ne, and iii) processing means (MT) arranged to extract from each portion of the base data layer said content, received by said receiver (R), at a chosen network layer, an inserted learning sequence, processed according to a configuration pattern identical to that used to process said improvement data layer, and then to estimate the quality of reception at from this extracted training sequence, and to order said activation means (MA) to activate the receiver (R) during the next time slot associated with said data layer of amelio the content of the selected channel when the estimated quality is greater than a selected threshold, so that it uses the next portion of the enhancement data layer received in addition to the portion of the base data layer to restore their content.

Terminal according to claim 14, wherein the processing means (MT) are arranged to estimate the reception quality by determining the value taken by a quality parameter relating to the extracted learning sequence, at a layer level. selected network, and for comparing said value with said selected threshold to determine whether they can allow said activation means (AM) to activate the receiver (R) during a next time slot associated with said content improvement data layer. of the selected channel.

Terminal according to claim 15, wherein said quality parameter is chosen from a group comprising at least the signal-to-noise ratio, the CIR, the bit error rate received (BER), the received erroneous frame rate ( FER), the received signal strength, the CRC, the received erroneous packet rate (PER), and the video perception quality.

17. Termina! according to one of claims 14 to 18, wherein said processing means (MT) are arranged, in the presence of content improvement data layers processed according to schemes of different configuration, for extracting from each portion of the base data layer of a content, at a chosen network layer, inserted learning sequences, respectively processed according to the configuration schemes used to process said data layers improving said content, then estimating the respective reception qualities of said enhancement data layers from said extracted training sequences, and ordering said activation means (AM) to activate the receiver (R) for the next time slice associated with a content improvement data layer of the selected channel when the corresponding estimated quality is greater than a selected threshold, so that it uses the next received portion of this enhancement data layer in addition to of the portion of the base data layer in order to reconstruct their content.

18, Terminal according to one of claims 14 to 16, wherein said processing means (MT) are arranged, in the presence of several layers of content improvement data processed according to the same configuration diagram, to estimate the receiving quality from the extracted training sequence, and ordering said activation means (AM) to activate the receiver (R) during the next time slot associated with each channel content improvement data layer. selected when the estimated quality is greater than a chosen threshold, so that it uses the next received portion of each enhancement data layer to complement the portion of the base data layer to reconstruct their content.