EP2545673A1

EP2545673A1 - Management of frequency resources during transmission and reception of signals in radio frequency system

Info

Publication number: EP2545673A1
Application number: EP11712968A
Authority: EP
Inventors: Laurent Cariou; Philippe Christin; David Bernard
Original assignee: France Telecom SA
Current assignee: Orange SA
Priority date: 2010-03-08
Filing date: 2011-03-04
Publication date: 2013-01-16
Also published as: US20130070697A1; US9036664B2; WO2011110778A1

Abstract

The invention relates to a method for transmitting data packets in a communication network using a plurality of radio frequency channels, at least two of said radio frequency channels being concatenated so as to form a concatenated channel. The method includes: a first step (21) of acquiring and reserving at least one of said radio frequency channels from said concatenated channel, thus reserving a first frequency band FB1 for transmitting data packets to a first target device; a second step (22) of acquiring and reserving radio frequency channels from said concatenated channel that were unreserved during said first step for acquisition and reservation, thus reserving a second frequency band FB2 for transmitting data packets to at least one second target device; at least one step of selecting a data packet from among said data packets that are to be transmitted to at least one second target device; a step of generating at least one preamble specific to said selected packet, the preamble(s) including at least one simultaneous transmission indicator on said first and second frequency bands; and a step (23) of simultaneously transmitting said data packets on said first and second frequency bands, from said selected packet and said specific preamble(s), before said selected packet on said second frequency band.

Description

MANAGEMENT OF FREQUENCY RESOURCES DURING TRANSMISSION AND RECEPTION OF SIGNALS IN A RADIO FREQUENCY SYSTEM

1. Field of the invention

The field of the invention is that of radiofrequency communications.

More specifically, the invention relates to the management of the frequency resources of equipment transmitting in a radiofrequency system, and more particularly a data packet transmission mechanism that can be used in this system.

The invention finds particular applications in the management of frequency resources of equipment emitting in frequency bands around 2.4GHz or 5GHz, in which in particular equipment according to IEEE 802.11a, b, g, n or revised and future versions, also called Wifi standards.

The term "equipment" here refers to an element belonging to a basic service set (BSS) formed by an access point ("access point") and the stations associated with this point of service. access, that is to say the stations located in the coverage area of this access point.

2. Prior Art

The various Wi-Fi IEEE 802.1 standards la, b, g, n use transmission frequency channels which may be equal to a frequency band of 20MHz or 40MHz (40MHz being a concatenation of two radio frequency channels, or frequency bands, without overlap of 20MHz), or even a transmission on a frequency band of 80MHz by concatenating four contiguous or non-contiguous radio frequency channels of 20MHz, in a future version of the WiFi standard IEEE 802.1 In.

Frequently, several Wifi access points are found on the same frequency bands and in the same spatial environment. These are referred to as "overlapping Basic Service Set". Under these conditions, a radio frequency channel, or a frequency band, must be shared between the different sets of basic services (BSS).

This is done conventionally using the CSMA-CA access mode, as described in the 802.11-2007 standard, section 9.1 "MAC architecture", 9.1.1 "DCF ".

The CSMA-CA mechanism, illustrated in FIG. 1, makes it possible to share access to a radio frequency channel according to a so-called contention principle: each equipment must listen for the channel to be free (that is to say, no signal is transmitted / received in this channel) for a variable duration, corresponding to an arbitrary interframe duration called AIFS (for "Arbitration InterFrame Space" in English) and a random waiting time (denoted B for "Backoff" in English) before transmitting data.

In practice, during the contention period, the access point decrements the "backoffs" of each packet waiting in the queues, as long as the channel is free.

In the case where several radiofrequency channels are concatenated, the listened channel is called primary channel, noted 1 in Figure 1 ("primary channel" in English).

In the case where the first packet in the queue has to be transmitted on a frequency band of 20MHz and is therefore likely to gain access to the channel (if no station takes control of the upstream channel before the end counting), only the primary channel is listened to (figure 1).

In the case of the future standard allowing transmissions on a frequency band of 80 MHz by concatenating four radiofrequency channels, next generation equipment, hereinafter referred to as "broadband" or "HT" equipment (for "High Throughput") , ie capable of implementing this standard, can therefore transmit on a frequency band of 80 MHz.

On the other hand, the equipment of old generation (able to implement the preceding norms), called thereafter equipment "legacy", can not transmit on a band of frequency of 80MHz.

However, for reasons of retrograde compatibility, the CSMA-CA mechanism allows each equipment, whether old or new generation, to "take control" of a channel, or a frequency band, to achieve a transmission at 20 MHz, 40 MHz or 80 MHz.

A disadvantage of this technique of the prior art lies in the fact that, if an access point takes control of a channel to transmit to a station "legacy" limited for example on a frequency band of 20MHz (or to a "HT" station for a packet that does not need to use more than 20MHz), the remaining 60 MHz of the 80 MHz frequency band of the concatenated channel are not used. The spectral efficiency of the basic set of services is severely reduced.

Similarly, a current technique, called the "20/40 mechanism" and defined in the IEEE 802.11η standard, for transmitting over a frequency band greater than 20 MHz, in this case 40 MHz, allows a device (a station or an access point) wishing to transmit data packets on a frequency band of 40MHz to a single user, called destination equipment (respectively the access point or a station), to reserve the frequency band of 40MHz, but not however, it is not possible to transmit data packets on a 40MHz frequency band to several destination devices.

Finally, the OEDMA multiple access technique makes it possible to transmit data packets to two destination devices over a frequency band of 80 MHz, using carriers that are separate from this frequency band for each of the destination devices and signaling to each of the recipient equipment which carriers are concerned. The destination equipment must therefore be compatible with this technique, in order to recognize the signaling enabling them to know which carriers are relevant to them. There is therefore a need for a new technique allowing optimal use of an available frequency band for transmitting data packets to different recipient equipment, whether old or new generation, so as to optimize efficiency. spectral and total throughput of a set of basic services,

3. Presentation of the invention

The invention proposes a new solution that does not have all of these disadvantages of the prior art, in the form of a method for transmitting data packets in a communication network using a plurality of radio frequency channels, at least two of the radiofrequency channels being concatenated to form a concatenated channel.

According to the invention, such a method comprises:

a first step of acquiring and reserving at least one of the radiofrequency channels of the concatenated channel, reserving a first frequency band for transmitting data packets to a first destination equipment; a second step of acquisition and reservation of the radio frequency channels of the non-reserved concatenated channel during the first acquisition and reservation step, reserving a second frequency band for the transmission of data packets destined for at least a second recipient equipment;

a step of simultaneously transmitting the data packets on the first and second frequency bands.

Thus, the invention is based on a new and inventive approach to the management of the frequency resources assigned to at least one equipment, in a communication network using a plurality of radio frequency channels, at least two of which are concatenated, or aggregated, to form a concatenated channel.

For example, a concatenated channel is composed of four radio frequency channels of 20 MHz, thus allowing transmission over 80 MHz.

In the context of Wi-Fi type communications for example, these destination devices correspond to stations associated with an access point, in a set of basic services (BSS) as described above in relation to the prior art.

In particular, according to the invention, a first step of acquiring and reserving a first frequency band, composed of at least one radiofrequency channel of the concatenated channel, is used to transmit data packets to a first recipient equipment. This first destination equipment is for example a "legacy" station, capable of transmitting and receiving 20 MHz data packets, or a "HT" station, capable of transmitting and receiving data packets on 20, 40 or 60 MHz.

According to a particular embodiment of the invention, this first step of acquiring and reserving a first frequency band implements the CSMA-CA mechanism, already described above in relation with the prior art and detailed further. For example, an access point attempts to access a 20 MHz frequency band, corresponding to a radio frequency channel of a concatenated channel of 80 MHz, and then reserves this frequency band, when it is free, for transmit data packets to a legacy station, or to transmit data packets that do not require a larger frequency band, to an associated "HT" station.

In another example, an access point attempts to access and reserve a first 40 MHz frequency band, then formed by two radiofrequency channels of the concatenated 80 MHz channel, to transmit data packets to a "HT" station. "Capable of transmitting and receiving on a frequency band of 40 MHz.

A second acquisition and reservation step consists in reserving a second frequency band formed of the radio frequency channels of the concatenated channel that are not reserved during the first step, for the transmission of the data packets to a second destination device.

Thus, again in the case of a concatenated 80 MHz channel, when an access point reserves a first 20 MHz frequency band (corresponding to a radio frequency channel) for transmitting data packets to a first destination device, for example a "legacy" station, the access point tries to access also a second frequency band of 60 MHz, corresponding to the other three radiofrequency channels not yet reserved, then the reserve, when it is free, to transmit data packets to a second destination equipment, for example an "HT" station.

According to another example, if an access point reserves a first frequency band of 40 MHz, then formed by two radiofrequency channels of the concatenated channel of 80 MHz, to transmit data packets to a station "HT", the point d access is also trying to access a second frequency band of 40 MHz, corresponding to the two other radiofrequency channels not yet reserved, then reserves this second frequency band, when it is free, to transmit data packets to a second "HT" station.

These first and second frequency bands are then used to simultaneously transmit the data packets to the first and second destination equipment respectively, thus optimizing the concatenated channel occupancy.

It should be noted that, in a particular embodiment of the invention, the first and second destination equipment can correspond to one and the same equipment.

According to one particular aspect of the invention, the method comprises at least one step of selecting a data packet from among the data packets to be transmitted to at least one second destination device, and the transmitting step transmits the selected packet on the second frequency band.

Indeed, since an access point may be requested by a plurality of associated stations, it may have a plurality of packets to be transmitted to a plurality of destination equipment, these packets being stored in one or more queues before being processed by the access point.

In addition, as seen above, the second frequency band reserved by the access point consisting of non-reserved radio frequency channels in the first acquisition and reservation step, it may have different characteristics. , depending on the first frequency band reserved. For example, it can allow transmission on 60, 40 or 20 MHz, depending on the size of the first reserved frequency band.

Thus, the method according to this embodiment of the invention therefore provides for selecting, among the data packets in the access point queue, the one or those that will be transmitted on the second reserved frequency band when the second stage of acquisition and reservation.

In this way, the access point chooses the packet or packets to be transmitted on the second frequency band so as to optimize its use.

For example, the selection step comprises a first substep of selecting a set of at least one data packet among the data packets to be transmitted to at least a second destination device, taking into account the transmission duration of the packets and the ability of the second recipient equipment to receive data packets on the second frequency band.

Thus, the access point chooses, among the data packets waiting for transmission, a set of packets destined for a destination device capable of implementing the invention, that is to say capable of transmitting and receive data packets on the second reserved frequency band. Indeed, among the pending packets, those to a "legacy" station can not be chosen, the "legacy" station not being able to receive on the second frequency band reserved.

Among this set of packets intended for stations capable of implementing the invention, a selection is then implemented as a function of the transmission duration of the packets present in the queue (s), and the second frequency band reserved.

For example, the first selection sub-step selects packets having a transmission duration less than the transmission duration of the packets to be transmitted to the first destination equipment.

Indeed, the transmission of the packets being simultaneous on the first and second frequency bands, the packets transmitted on the second frequency band must not be longer to transmit than those transmitted on the first frequency band, the transmission times packets being calculated taking into account the respective characteristics of the first and second frequency bands.

In another example, at least two packets of the set are aggregated to form a single packet.

Thus, if the packet or packets selected to be transmitted on the second frequency band to the second destination equipment, simultaneously with those transmitted on the first frequency band to the first destination equipment, have a transmission time shorter than that of the packets to be transmitted on the first frequency band, the method according to the invention allows aggregating packets present in the queue (s), to the second destination equipment, for example according to a known technique defined in the IEEE 802.11η standard.

Once a set of packets has been selected, among the packets present in the queue (s) to be transmitted by the access point, the selection step comprises a second substep of selecting a packet of data in the set, delivering the selected packet, the second substep of selection taking into account at least one of the criteria belonging to the group comprising:

a priority criterion taking into account the data type of the packet;

a transmission time of the data packet for one. predetermined transmission rate.

Thus, the method according to this embodiment of the invention makes it possible to optimize

3 'use of the second frequency band, choosing a packet to be transmitted on the second frequency band, simultaneously with that transmitted on the first frequency band, according to a predefined optimization criterion.

For example, an optimization criterion is a priority criterion that is understood in terms of the data type of the packet, or the class of service to which the packet in question belongs. For example, a "Best Effort" (ie, no particular priority), or "Background" (ie, last deal) package is less of a priority than a packet of "Voice" type, requiring real-time transmission, or a "Video" type packet, requiring high quality transmission. These classes of service are, for example, indicated in the "Qos control / TE" field of the MAC header §7.1.3.5 of the 802.11e standard.

Another optimization criterion may take into account the transmission duration of the packet, relative to a predetermined transmission rate, for determining a penalty factor associated with a packet, representing an estimated occupation of the channel for the transmission of this packet. Thus, a criterion may consist in choosing the package that would penalize the other recipient equipment the most, if it were transmitted in a "conventional" manner, for example using only a 20 MHz frequency band.

These criteria are described in more detail below, in connection with embodiments of the invention.

According to a particular embodiment of the invention, the method comprises a step of generating at least one preamble specific to the selected packet, the preamble or preambles comprising at least one simultaneous transmission indicator on the first and second frequency bands. and the sending step emits the specific preamble or preambles, before the selected packet, on the second frequency band.

This embodiment of the invention corresponds to a transmission to a "legacy" station on the first frequency band, and a transmission to a "HT" station, able to implement the invention, on the second frequency band. .

This embodiment makes it possible to signal to the second recipient equipment, via one or more preambles, the simultaneous transmission on the first and second frequency bands, so that it can decode the packets intended for it, that is to say ie those issued on the second frequency band.

In particular, this or these preambles (according to alternative embodiments) are only transmitted on the second frequency band, so as not to modify the transmission to a first recipient equipment "legacy" on the first frequency band .

Simultaneous transmission on the first and second frequency bands is therefore "hidden" for this "legacy" equipment, thus making it possible to respect the retrograde compatibility constraint.

According to a second embodiment, the method comprises a step of generating at least one preamble specific to the data packets destined for the first recipient equipment, the specific preamble or preambles comprising at least one simultaneous transmission indicator on the first and second frequency bands and the transmitting step transmits the specific preamble or preambles, before the packets, on the first frequency band.

This embodiment corresponds to a transmission to a first "HT" station, able to implement the invention, on the first frequency band, and a transmission to a second "HT" station, able to implement the invention, on the second frequency band.

This embodiment makes it possible to signal to the first recipient equipment, via one or more preambles, the simultaneous transmission on the first and second frequency bands, so that it can decode the packets intended for it, that is to say ie those issued on the first frequency band.

According to this embodiment, it is also planned to generate at least one preamble specific to the selected packet, the preamble or preambles comprising at least one simultaneous transmission indicator on the first and second frequency bands and the transmission step transmitting the specific preamble or preambles, before the selected packet, on the second frequency band.

Thus, the second destination equipment, here the second "HT" station capable of implementing the invention, is also informed of the simultaneous transmission, so that it can decode the packets intended for it, that is, ie those issued on the second frequency band.

It should be noted that the preambles, emitted respectively on the first or the second frequency band, are specific to the packets to be transmitted respectively to the first and second "HT" stations, able to implement the invention. In particular, the specific preamble further comprises at least one indicator belonging to the group comprising:

command indicator of the simultaneous transmission;

indicator of the radio frequency channel (s) making up the second frequency band; an indicator of the radio frequency channel (s) making up the first frequency band; indicator of the second recipient equipment;

indicator of the first recipient equipment.

Thus, according to different variants of the invention, the specific preamble or preambles, issued to inform of a simultaneous transmission stations "HT" capable of implementing the invention and recipients of data packets transmitted on the first and / or the second frequency bands, also include indicators to better define this simultaneous emission.

For example, an indicator indicates that the simultaneous transmission is implemented on channel 2 of the concatenated channel, knowing that the radio frequency channel used to form the first frequency band for transmission to a "legacy" station is denoted channel 1.

In another example, an indicator indicates that channels 2 to 4 of the concatenated channel forming the second frequency band are used for transmission to a "HT" station implementing the invention.

According to yet another example, an indicator indicates an identifier of a recipient equipment "HT", so that it can be informed packages intended for it, etc..

According to a particular characteristic of the invention, the first and second acquisition and reservation steps implement:

listening to one of the radiofrequency channels comprising the first frequency band, denoted primary channel, for a predetermined duration, and

listening to the other radiofrequency channels of the concatenated channel for a duration equal to an interframe for access controlled by a transmission equipment, denoted PIFS, having an end coinciding with the end of the predetermined duration.

Thus, according to one embodiment of the invention, the first acquisition and reservation step implements the known mechanism for accessing the CSMA-CA channel, already described in relation with the prior art, and consisting of listening a channel called a primary channel, for a variable duration, corresponding to an arbitrary interframe duration called AIFS (for "Arbitration InterFrame Space" in English) and a random waiting time (denoted B for "Backoff" in English), before transmitting Datas.

According to this embodiment, the second acquisition and reservation step implements a simplified mechanism for listening to the other channels forming the concatenated channel, during a period noted PIFS, shorter than the period AIFS, and whose end coincides with the end of AIFS.

Thus, if the primary channel and the other channels being listened to are free, the simultaneous transmission can begin on the first and second frequency bands reserved. In this way, even if the access point only has to send packets on the primary channel, to a "legacy" station for example, it listens to the other channels of the concatenated channel, called secondary channel, tertiary and quaternary, in the case of a concatenated channel of 80 MHz and is therefore informed of the occupation of these channels, at the same time as the occupation of the _. primary channel.

According to a particular characteristic of the invention, the method comprises a step of receiving, on at least one of the radiofrequency channels comprising the first frequency band, denoted primary channel, acknowledgments associated with the packets transmitted simultaneously on the first and second frequency bands. .

Thus, the access point receives, on the primary channel, acknowledgments for receiving packets transmitted simultaneously on the first and second frequency bands, from the destination equipment of these packets. Thus, even if the packets are transmitted on channels other than the primary channel, the acknowledgments are received on the primary channel by the access point, making it easier to manage acknowledgments for all the packets transmitted simultaneously.

Another aspect of the invention relates to equipment for transmitting data packets in a communication network using a plurality of radio frequency channels, wherein at least two of the radio frequency channels are concatenated to form a concatenated channel.

According to the invention, such transmission equipment comprises:

first means for acquiring and reserving at least one of the radiofrequency channels of the concatenated channel, reserving a first frequency band for transmission of data packets to a first destination equipment; . second means for acquiring and reserving the radiofrequency channels of the concatenated channel not reserved by the first acquisition and reservation means, reserving a second frequency band for transmitting data packets to at least one second destination equipment ;

means for simultaneously transmitting data packets on the first and second frequency bands.

Such transmission equipment is particularly suitable for implementing the transmission method described above. This is for example an access point or a Wifi station.

This transmission equipment may of course include the various characteristics relating to the transmission method according to the invention. Thus, the characteristics and advantages of this transmission equipment are the same as those of the transmission method, and are not detailed further.

The invention also relates to a method for receiving data packets in a communication network using a plurality of radiofrequency channels, wherein at least two of the radiofrequency channels are concatenated to form a concatenated channel.

According to the invention, such a reception method comprises: a step of receiving data packets transmitted simultaneously on a first and a second frequency band, the first frequency band being formed of at least one of the radiofrequency channels of the concatenated channel and the second frequency band being formed of the other radio frequency channels the concatenated canal;

a step of decoding the data packets transmitted on only one of the first and second frequency bands as a function of the signaling received on at least one of the first and second frequency bands.

Thus, the reception method according to the invention is based on a novel and inventive approach to the decoding of data packets, when these packets are transmitted simultaneously on two frequency bands, making it possible to decode only the data packets transmitted on one or the other of these frequency bands, according to a signal transmitted on one or the other of these frequency bands.

This signaling informs a destination equipment of the frequency band that is intended for it, and on which the equipment then decodes the data packets.

For example, when the reception method according to the invention is implemented in a "HT" station, it receives the data transmitted simultaneously on the two frequency bands and only decodes the data intended for it, for example those issued on the second frequency band reserved. The "HT" station is informed of the destination of the data by specific signaling, received before the data packets, on this second frequency band.

If the data packets transmitted on the first frequency band are destined for a "legacy" station, no specific signaling is transmitted on the first frequency band, and the "legacay" station is not informed of simultaneous transmission of packets on a second frequency band to another equipment.

In particular, the reception method comprises a step of receiving at least one specific preamble transmitted on the first and / or second frequency band (s), and the decoding step is implemented either on the transmitted packets on the first frequency band, ie on the packets transmitted on the second frequency band, as a function of at least one simultaneous emission indicator present in the specific preamble or preambles.

According to one embodiment of the invention, the data packets transmitted on each of the reserved frequency bands are preceded by a specific preamble, so as to inform the destination equipment of the frequency band intended for them. Thus, once the signaling received and processed, the destination equipment only decodes the packets intended for them.

According to a particular characteristic of the invention, the reception method comprises a step of transmitting, on one of the radio frequency channels comprising the first frequency band, denoted primary channel, an acknowledgment of reception of a packet transmitted on the second Band frequency, the step of transmitting an acknowledgment being implemented after detecting a reception acknowledgment of a transmitted packet simultaneously on the first frequency band.

Thus, the receiving equipment transmitted packets on the second frequency band transmits an acknowledgment of receipt of these packets on the primary channel to the access point. In addition, the transmission of this acknowledgment by the destination equipment is implemented after detection of the transmission of the acknowledgment corresponding to the reception of the transmitted packets simultaneously on the first frequency band. In this way, the access point first receives the acknowledgment of reception of the packets transmitted on the first frequency band, then the acknowledgment of reception of the packets transmitted on the second frequency band, whatever the size of the packets. transmitted on the second frequency band.

This mechanism thus allows an acknowledgment management independent of the frequency bands and the size of the packets transmitted on these frequency bands.

The invention also relates to a recipient equipment for receiving data packets in a communication network using a plurality of radio frequency channels, at least two of the radiofrequency channels being concatenated to form a concatenated channel.

According to the invention, such recipient equipment, or station, comprises:

means for receiving data packets transmitted simultaneously on a first and a second frequency band, the first frequency band being formed of at least one of the radiofrequency channels of the concatenated channel and the second frequency band being formed of the radiofrequency channels of the non-reserved concatenated channel;

means for decoding data packets transmitted on only one of the first and second frequency bands as a function of the signaling received on at least one of the first and second frequency bands.

Such equipment is particularly adapted to implement the reception method described above. This is for example a station of a set of basic services, in the case of wireless transmission.

This equipment can of course include the various characteristics relating to the reception method according to the invention. Thus, the features and benefits of this equipment are the same as those of the receiving method, and are not detailed further.

Another aspect of the invention relates to a multicarrier signal transmitted in a communication network using a plurality of radiofrequency channels, wherein at least two of the radio frequency channels are concatenated to form a concatenated channel.

According to the invention, such a signal carries data to a first destination equipment on carriers belonging to a first frequency band and data to a second destination equipment on carriers belonging to a second frequency band. , the first frequency band being formed of at least one of the radiofrequency channels of the concatenated channel and the second frequency band consisting of other radiofrequency channels of the concat channel.

In particular, such a signal carries at least one simultaneous emission indicator on the first and second frequency bands. Such a signal can be generated by the transmission method described above.

The invention also relates to a computer program comprising instructions. for carrying out a transmission method or reception method as previously described when this program is executed by a processor.

4. List of figures

Other features and advantages of the invention will appear more clearly on reading the following description of a particular embodiment, given as a simple illustrative and nonlimiting example, and the appended drawings, among which:

Figure 1, already commented in relation to the prior art, illustrates an example of channel access mechanism;

Figure 2 shows the main steps of the transmission method according to one embodiment of the invention;

Figures 3a and 3b show an example of the channel access mechanism according to one embodiment of the invention;

FIGS. 4a and 4b describe two signaling examples according to embodiments of the invention;

FIG. 5 illustrates an example of a simplified structure of an access point according to one embodiment of the invention;

FIG. 6 presents the main steps of the reception method according to one embodiment of the invention;

FIGS. 7a and 7b describe two examples of acknowledgment mechanism according to embodiments of the invention;

FIG. 8 illustrates an example of a simplified structure of a recipient equipment according to one embodiment of the invention.

5. Description of an embodiment of the invention

5.1 General principle

The general principle of the invention is based on the simultaneous transmission of data packets, destined for two recipient equipments, on two frequency bands, each formed of at least one radiofrequency channel of a concatenated channel, thus enabling optimize the concatenated channel occupancy.

Recall that a concatenated channel is a channel corresponding to the concatenation of several radio frequency channels, used for multi-channel transmission.

Thus, as illustrated in FIG. 2, the transmission method according to one embodiment of the invention comprises a first step 21 of acquiring and reserving a first frequency band, denoted FBI, for the transmission of data packets to a first destination equipment. This first frequency band is composed of at least one radiofrequency channel of a concatenated channel.

During a step 22 for acquiring and reserving a second frequency band, denoted FB2, the radiofrequency channels of the non-reserved concatenated channel are reserved in the first step, that is to say not included in the FBI frequency band for transmitting data packets to at least a second destination equipment.

A third TX transmission step 23 consists in sending simultaneously on the first frequency band FBI and the second frequency band FB2 data packets destined to the first and second destination devices respectively.

Thus, all of the radiofrequency channels forming the concatenated channel are used to simultaneously transmit data packets to two or more recipient devices.

In reception, the principle of the invention is based on the simultaneous reception of packets on the first and second frequency bands and on the decoding of the packets on one or the other of these two frequency bands as a function of a signaling received on one and / or the other of the frequency bands.

5.2 Detailed description of an embodiment of the transmission method

5.2.1 Acquisition and reservation of frequency bands

A particular embodiment of the invention is described below.

In particular, first of all, in relation with FIGS. 3a and 3b, the acquisition and reservation steps of the first and second frequency bands are described by the implementation of a channel access mechanism according to this method. embodiment of the invention.

In these figures, the left side represents queues and packets stored waiting for transmission by the access point, and the right side represents the packets being transmitted. The packages shown with stripes on the left side are those that have been selected for the transmission shown on the right side.

In addition, we consider here an example with a concatenated channel of 40 MHz, that is to say composed of two radio frequency channels of 20 MHz, the primary channel 1 and the secondary channel noted 2.

In a first case illustrated in FIG. 3a, it is considered that the first packet in the access point queue must be transmitted over a frequency band of 20 MHz to a "legacy" station. ΰ is shown on the left side of Figure 3a with stripes and an indication "CW = 4", which corresponds to the value of the "backoff". This value is actually lower than the other two values, respectively equal to 5 and 6, in the other two queues, that is why this packet is the next to be transmitted, if the channel 1 is free.

When the channel 1 is free, it is used for the transmission of this packet to a "legacy" station, and, according to the invention, a second frequency band, composed of the channel 2, is used for the transmission of other packets to a destination equipment "HT". Acquisition and reservation are effected, according to this embodiment of the invention, by listening to the channel 2 for a duration called "PIFS", ending at the same time as the listening time ("AIFS + B") of the channel 1, as already described above.

Thanks to the invention, the access point is informed if the primary channel 1 and secondary channel 2 are free or busy, even if the next packet to be transmitted is destined for a "Iegacy" station and therefore to be transmitted only on the primary channel 1 (20MHz).

If the channels 1 and 2 are free, and as illustrated on the right-hand part of FIG. 3a, a packet destined for an "Iegacy" station, denoted "Legacy 20 MHz", is transmitted on the channel 1, simultaneously with the sending a packet to an "HT" station, denoted "HT 20 MHz", on the channel 2.

In a second case illustrated in FIG. 3b, it is considered that the next packet to be transmitted must be transmitted on a frequency band of 20 MHz to an "HT" station. It is shown on the left side of Figure 3b with stripes and an indication "CW = 5", which corresponds to the value of the "backoff". This value is actually lower than the other two values, respectively equal to 6 and 8, in the other two queues, that is why this packet is the next to be transmitted, if the channel 1 is free.

When the channel 1 is free, it is used for the transmission of this packet to a "HT" station, and, according to the invention, a second frequency band, composed of the channel 2, is used for the transmission of other packets to another "HT" station. Acquisition and reservation are performed, according to this embodiment of the invention, listening to the channel 2 for a duration called "PIFS", ending at the same time as the listening time ("AIFS + B") of channel 1, as already described above.

Thanks to the invention, the access point is informed if the primary channel 1 and secondary 2 are free or busy, even if the next packet to be transmitted to a station "HT" requires only 20 MHz.

If the channels 1 and 2 are free, and as illustrated on the right-hand part of FIG. 3b, a packet destined for a first "HT" station, denoted "HT1 20 MHz", is transmitted on the channel 1, simultaneously with the emission of a packet destined for a second "HT" station, denoted "HT2 20 MHz", on the channel 2.

5.2.2 Selection of a data packet to be transmitted on the second frequency band

The mechanism for selecting the packet to be transmitted to an "HT" station on the second reserved frequency band is now described in more detail.

In a general manner, once the first and second frequency bands have been reserved, the transmission method according to this embodiment of the invention provides for selecting the packet or packets that can be transmitted on the second frequency band, destination of a "HT" station. Indeed, according to the characteristics of the second frequency band reserved, and in particular its width, that is to say the number of radio frequency channels which form it (for example two or three 20 MHz channels of a concatenated channel formed through four 20 MHz radio frequency channels), some packets waiting in the access point queues are more or less appropriate to be transmitted on this second frequency band.

The mechanism for selecting a packet to be transmitted on the second frequency band, simultaneously with the transmission of a packet on the first frequency band, consists first of all in selecting a set of packets intended for "HT" stations. , thus "eliminating" the packets destined for "legacy" stations, which stations can not implement the invention, and consequently can not receive packets on the second frequency band reserved according to the invention.

Then, from this set of packets, another selection is implemented, consisting in selecting the packet or packets having a transmission duration T less than the transmission duration of the packet to be transmitted simultaneously on the first frequency band. This transmission duration T is calculated by taking into account the characteristics of the second frequency band (20 MHz in the examples of FIGS. 3a and 3b).

This constraint is due to the fact that the simultaneous transmission of the packets on the first and second frequency bands must allow the "legacy" stations to operate without modification, and thus without having to take into consideration a simultaneous transmission on another frequency band. . To do this, the duration of transmission of the packet on the second frequency band must be less than that of the packet on the first frequency band to pass "unnoticed" for a "legacy" station. As a result, when the transmission on the first band is completed, that on the second band is also released, thus freeing the two frequency bands for subsequent transmissions.

On the other hand, if the set of packets comprises only packets of transmission duration T which is much smaller than that of the packet transmitted on the first frequency band, it is possible to implement a packet aggregation, for example using aggregation techniques defined in the IEEE 802.11η standard, so as to "fabricate" an aggregated packet whose transmission duration is close to that of the packet transmitted on the first frequency band, while remaining lower.

This selection criterion based on the transmission duration makes it possible to optimize the use of the concatenated channel's radio frequency channels.

Among the selected packets, ie packets intended for "HT" stations and having a transmission duration T less than that of the packet transmitted on the first frequency band, a single packet must be chosen to be effectively transmitted on the second frequency band simultaneously with the packet transmitted on the first frequency band.

Another selection is therefore implemented, applying at least one selection criterion a criterion taking into account the data type of the packet, or the class of service to which the packet belongs. For example, a package of the type "Best Effort", or "Background", is less of a priority than a "Voice" type packet, requiring a real-time transmission, or a "Video" type packet, requiring a high quality transmission. These classes of service are for example reported in the Cham "Qos control / TE ⁾ " of the MAC header §7.1.3.5 of the 802.11e standard. Such a criterion is especially chosen when one wants to privilege the quality of service compared to the flow.

a criterion taking into account the duration of transmission of the packet, relative to a predetermined transmission rate (for example a transmission over 20 MHz with a particular modulation), making it possible to determine a penalty factor associated with a packet, representing an estimated occupation of the channel for the transmission of this packet. Thus, such a criterion may consist in choosing the package that would penalize the other recipient equipment the most, if it were transmitted in a "conventional" manner, for example using only a 20 MHz frequency band. For example, we define a penalty factor FplÇPi), for a packet Pi, corresponding to the total time of occupation of the channel by the packet, noted T (Pi). This time T {Pi) is calculated taking into account the frequency band conventionally used (for example 20 or 40 MHz according to the packets) and the transmission rates envisaged by the access point for transmitting this packet Pi, as well as the transmission of the physical layer headers of the communication network (the latter being organized into a plurality of communication layers comprising a data link layer, called MAC layer, delivering data packets to a physical layer, called PHY layer ) and acknowledgments of receipt of the packets. Such a criterion is chosen especially when one wants to privilege the flow with respect to the quality of service,

a criterion corresponding to a combination of the two preceding criteria, that is to say taking into account both the priority of the packet and its total time of occupation of the channel, noted T (Pi). Thus, a penalty factor Fp2 (Pi), corresponding to an average of the temporal occupation T (Pi) and the priority of the packets, is defined. The temporal occupation T (Pi) is calculated taking into account the frequency band conventionally used (for example 20 or 40 MHz depending on the packets) and the transmission rates envisaged by the access point for transmitting this packet Pi, as well as transmission of headers of the physical layer of the communication network and acknowledgments of receipt of the packets. The temporal occupation T (Pi) is then divided by occupation temporal minimum among the packets to be selected, namely: min (T (Pi)), for i = 0 ... Pi_max. The priority of the packets is calculated from the contention window denoted CW (Pi), divided by the minimum contention window among the packets to be selected; is ; min (CW (Pi)), for i = 0 ... Pi_max. Thus, the penalization factor is written: Fp2 (Pi) = T (Pi) / rnin (T (Pi)) + CW (PI) / min (CW (Pi)), i = 0 ... Pi_max, the package with the smallest Fp2 (Pi) being selected. Such a criterion is particularly chosen when one wants to privilege an intermediate approach between the quality of service and the flow.

Once at least one of these selection criteria has been applied, a signaling step, described below, is implemented, before the actual transmission of the packets.

5.2.3 Signaling of simultaneous transmission on two frequency bands

We will now describe, in relation with FIGS. 4a and 4b, the signaling implemented according to this embodiment of the invention enabling, on the one hand, a "legacy" station to receive packets on the first frequency band. appropriately reserved and without being informed of the simultaneous transmission on the second frequency band, and, on the other hand, the "HT" station receiving the packets on the second frequency band to receive, detect and correctly decode these packets.

Consider again the two examples illustrated in FIGS. 3a and 3b, namely:

a first example in which a packet destined for a "legacy" station is transmitted on the first reserved frequency band, simultaneously with the transmission of a packet destined for a "HT" station on the second frequency band ;

a second example in which a packet destined for a first station "HT1" is transmitted on the first reserved frequency band, simultaneously with the transmission of a packet destined for a second station "HT2" on the second band frequency.

In the first example, the data destined for the "legacy" station is placed on the sub-carriers corresponding to the primary channel 1 and the data intended for the "HT" station on the sub-carriers corresponding to the secondary channel 2, as illustrated in Figure 4a.

Preambles specific to the "HT" station, denoted HT-S, HT-STF and HT-LTFs, are emitted on the secondary channel, after the emission of the "legacy" signaling preambles, denoted L-STF, L-LTF. and L-SIG, including synchronization information.

According to a first variant embodiment, these preambles notably comprise a "simultaneous transmission" field in the HT-S signaling that a simultaneous transmission is active. In this way, the "HT" station receiving the data on the second frequency band is informed of the simultaneous transmission.

According to a second variant embodiment, a field in the HT-SIM also signals the order of the simultaneous transmission, that is to say that the simultaneous transmission is implemented on the channel 2, knowing that the radiofrequency channel used to form the first frequency band for transmission to a station "legacy Is noted channel 1.

According to a third variant, a field in the HT-SIM makes it possible to signal the channels used by the simultaneous transmission, for example the channel 2 (if the concatenated channel comprises only two radio frequency channels) or the channels 2 to 4 (if the channel concatenated comprises four radiofrequency channels forming the second frequency band are used for transmission to a station "HT" implementing the invention.

For example, considering the first example illustrated in FIG. 3a, corresponding to a concatenated channel of 40 MHz, we observe:

on primary channel 1: the issuance of "legacy" preambles, as defined by the "legacy" standards;

on the secondary channel.2: the emission of preambles specific to the station "HT" with in the HT-S the field corresponding to the primary channel set to 0 and the field corresponding to the secondary channel set to 1.

Similarly, if one considers a concatenated channel of 80 MHz (that is to say formed of four radio frequency channels of 20 MHz), with a packet of data transmitted to a "legacy" station on the primary channel 1 and a data packet transmitted simultaneously to a "HT" station on the secondary 2, tertiary 3 and quaternary 4 channels, forming a second frequency band of 60 MHz, we observe:

on the secondary channel 2: the emission of preambles specific to the station "HT" with in the HT-SM the field corresponding to the primary channel set to 0 and the fields corresponding to the secondary, tertiary and quaternary channels set to 1; on the tertiary channel: the same preambles as on the secondary channel, according to a technique similar to the known duplication technique of the 802.11η standard, called "duplicate mode", making it possible to duplicate the signal transmitted on the primary channel in the secondary channel using a dual size Fourier transform ("FFT") and copying the data transmitted on the subcarriers corresponding to the primary channel to the subcarriers corresponding to the secondary channel;

on the quaternary channel: the same preambles as on the secondary channel, according to the technique similar to the "duplicate mode" described above.

According to a fourth variant, the field in the HT-SIM also makes it possible to signal an identifier of a recipient device "HT", so that it can be informed of the packets intended for it. This identifier is for example the "AID" (of the English "Association Identify ") of the station or a hash function between Y" AID "and the" BSSID "(Basic Service Set Identifier).

For example, considering the first example illustrated in Figure 3a, corresponding to a concatenated channel of 40 MHz, is observed;

on the secondary channel 2: the emission of preambles specific to the station "HT" with in the HT-SIM the field corresponding to the primary channel set to 0 and the field corresponding to the secondary channel set to 1, and an additional field, noted for example "destination", indicating the identifier of the destination station. Similarly, if we consider a concatenated channel of 80 MHz, we observe:

on the secondary channel 2: the emission of preambles specific to the station "HT" with in the HT-SUvI the field corresponding to the primary channel set to 0 and the fields corresponding to the secondary, tertiary and quaternary channels set to 1 and a field additional, noted for example "destination", indicating the identifier of the destination station;

on the tertiary channel: the same preambles as on the secondary channel, according to a technique similar to the duplication technique of the 802.11η standard, called "duplicate mode", making it possible to duplicate the signal transmitted on the primary channel in the secondary channel by using a dual-size FFT and copying the data transmitted on the sub-carriers corresponding to the primary channel to the sub-carriers corresponding to the secondary channel;

It should be noted that when the identifier of the destination station is signaled in the preambles, it is informed upon receipt of these preambles that the packets transmitted on the second frequency band are intended for it, and can therefore from that moment decode only the packets transmitted on this second frequency band.

On the other hand, when the identifier of the destination station is not signaled in the preambles, it must decode both the data transmitted on the first frequency band and those transmitted on the second frequency band, because the Destination information is only present at the level of the MAC layer and therefore accessible only after decoding of the PHY layer.

We now consider an example where packets destined for a first station "HT1" are transmitted on the first frequency band and packets destined for a second station "HT2" are transmitted on the second frequency band (as for example the case illustrated in Figure 3b).

In this case, the data destined for the first station "HT1" are placed on the sub-carriers corresponding to the primary channel 1 and the data destined for the second station "HT2" on the sub-carriers corresponding to the secondary channel 2, as illustrated in Figure 4b.

Preambles specific to the first "HT1" station, denoted HT-SM, HT-STF and HT-LTFs, are emitted on the primary channel, after the emission of the "legacy" signaling preambles, denoted L-STF, L- LTF and L-SIG, including synchronization information.

Similarly, preambles specific to the second station "H.T2", denoted HT-SM, HT-STF and HT-LTFs, are emitted on the primary channel, after remission of the signaling preambles "legacy".

These preambles are the same as those described above, with their different variants.

Thus, the preambles specific to the first station "HT1" signal for example that a simultaneous transmission is active (field "simultaneous transmission" = 1) and the channels occupied by this transmission (channel

As seen above, it is also possible to report the identifier of the destination station of the transmission (HT1).

Similarly, the preambles specific to the first station "HT2" signal for example that a simultaneous transmission is active (field "simultaneous transmission" ~ V) and the channels occupied by this transmission (primary channel = 0 and secondary channel = 1) . As seen above, it is also possible to signal the identifier of the destination station of the transmission (HT2).

Similarly, if we consider a concatenated channel of 80 MHz (that is to say formed of four radiofrequency channels of 20 MHz), with a packet of data transmitted to a first station "HT1" on the channels primary 1 and secondary 2, forming a first frequency band of 40 MHz, and a packet of data transmitted simultaneously to a second station "HT2" on tertiary channels 3 and 4, forming a second frequency band of 40 MHz, we observe :

on the primary channel 1: the emission of preambles specific to the station "HT1" with in the HT-SM the field corresponding to the primary channel set to 1, the field corresponding to the secondary channel set to 1 and the fields corresponding to the tertiary channels and quaternary set to 0, the field "simultaneous transmission" set to 1, and the field "destination" set to "HT1";

on the secondary channel 2: a duplication of the preambles of the primary channel;

on the tertiary channel 3: the emission of preambles specific to the station "HT2" with in the HT-SM the field corresponding to the primary and secondary channels set to 0 and the fields corresponding to the tertiary and quaternary channels set to 1, the "simultaneous transmission" field set to 1, and the "destination" field set to "HT2"; on the quaternary canal 4: a duplication of the preambles of the tertiary canal. Once these preambles have been transmitted, the actual data is transmitted on the reserved frequency bands.

5.3 Structure of an access point

FIG. 5 illustrates an example of a simplified structure of an access point according to one embodiment of the invention, for example for a simultaneous transmission of PI and P2 packets of data respectively on a primary channel 1 destined for an first destination equipment and on a secondary channel 2 to a second destination equipment.

The generation of data and preambles is independent between the two primary channels 1 and 2. Thus, the means for generating data and preambles 51 for the packet PI transmitted on the primary channel are distinct from the means for generating the data and preambles 52 for the P2 packet sent on the secondary channel.

On the other hand, the physical layer transmission means 53 are partially shared, as illustrated in FIG. 5, in particular as regards the binary to symbol coding, the OFDM modulation.

According to one variant, the transmission means 53 can also be completely independent.

Such an access point also comprises means for acquiring and reserving the frequency bands, implemented before the generation means 1 and 52.

5.4 Detailed description of an embodiment of the reception method

With reference to FIG. 6, the main steps of the reception method according to one embodiment of the invention will now be described.

In a first reception step 61, the data packets transmitted simultaneously on the frequency bands FBI and FB2 are received, and in particular signaling information enabling the destination equipment implementing the reception method according to this mode. realization of knowing on which frequency band are sent the packets intended for it.

Thus, during a step 62, the signaling information is processed, and the packets PI received on the frequency band FBI or the packets P2 received on the frequency band FB2 are decoded, during a step 631 or 632 of decoding, depending on the signal received. These decoding steps 631 and 632 are implemented on one or the other of the frequency bands FBI or FB2.

As already indicated above, when the signaling indicates an identifier of the recipient device, the latter is then informed of the packets intended for it and can decode the packets on the frequency band which concerns it, by not treating the packets received on the other frequency band. When the signaling indicates that a simultaneous transmission is active, without identifying the destination equipment concerned, each device must implement decoding at the MAC layer to know which packets are intended for it.

We now consider the case of a "HT" station for which packets are transmitted on a second frequency band, simultaneously with packets transmitted on a first frequency band, to a "legacy" station.

This particular situation of the invention has particularities related to the fact that the duration of transmission of the packets on each of the two frequency bands is not necessarily the same and that the transmission characteristics (modulation, coding, ... ) can be different and therefore the acknowledgments of reception of the packets, emitted by each of the destination stations, can also be of different sizes.

The invention therefore provides a specific mechanism for managing the reception acknowledgments of the packets transmitted by each of the destination stations, making it possible to transmit, on the primary channel only, the acknowledgments of reception of the packets transmitted on the two frequency bands, such as illustrated in Figures 7a and 7b.

The reception acknowledgments are sent on the primary channel in a predetermined order corresponding to the ascending order of the channels in the concatenated channel. For example, the reception acknowledgment of packets on the primary channel is transmitted first, then that of the packets received on the secondary channel, and so on for the tertiary and quaternary channels in the case of a concatenated channel of 80 MHz .

To do this, the "HT" station receiving packets on the second frequency band listens to the primary channel as soon as the second frequency band is released, at the end of the transmission of a packet, in order to detecting the end of the transmission of the acknowledgment of reception of the packet on the primary channel. This detection is based for example on the short interframe, denoted SFIS, for "Short inter Frame Spacing" in English.

When the SFIS is detected, the "HT" station can then transmit the acknowledgment corresponding to the reception of the packet on the second frequency band.

FIG. 7b illustrates more particularly the case where the transmission duration of the packet transmitted on the second frequency band is less than that of the packet transmitted on the primary channel. In this case, the second frequency band is released at the end of transmission, without the need for the transmission of stuffing packets to match the transmission time of the packet on the second frequency band with that of the packet transmitted on the second frequency band. first frequency band.

5.5 Structure of a recipient equipment

FIG. 8 illustrates an example of a simplified structure of a destination equipment according to one embodiment of the invention, for example for receiving data packets sent simultaneously on a primary channel 1 to a first destination equipment and on a secondary channel 2 to a second destination equipment.

Consider for example the case of a recipient equipment embodying the invention, for example a "HT" station, to which packets are transmitted on the secondary channel 2.

First means 81 for processing synchronization information L-STF and L-

LTF as well as channel estimation means 82 are shared between the two channels 1 and 2.

On the other hand, separate means 831 and 832 for processing the L-GIS signaling information are implemented for each of the channels I and 2. Indeed, as already described above, preambles specific to the "HT" station are transmitted on the EB2 frequency band, while "legacy" preambles are transmitted on the FBI frequency band (if the packets transmitted on this frequency band are destined for a "legacy" station).

From the processing of the signaling information, the means implemented for the reception of the packets on each of the two frequency bands, thus, that the decoding means, are distinct.

For example, separate data detection means 841 and 842 are implemented for decoding purposes.

According to a variant, not shown, the data received on the secondary channel are stored in a buffer, for subsequent processing.

It is also possible that a destination equipment is directly designed to receive data transmitted according to the invention, in which case the signaling information is not necessary.

Claims

A method of transmitting data packets in a communication network using a plurality of radio frequency channels,

at least two of said radiofrequency channels being concatenated to form a concatenated channel, characterized in that it comprises:

a first step of acquiring and reserving (21) at least one of said radiofrequency channels of said concatenated channel, reserving a first frequency band (FBI) for transmitting data packets to a first destination equipment;

a second step of acquiring and reserving (22) the radiofrequency channels of said non-reserved concatenated channel during said first acquisition and reservation step, reserving a second frequency band (FB2) for transmission of data packets to at least one second recipient equipment;

at least one step of selecting a data packet from among said data packets to be transmitted to at least a second destination device,

a step of generating at least a specific preamble to said selected packet, said one or more ^"preambles comprising at least one of simultaneous transmission indicator to said first and second frequency bands,

a step of simultaneously transmitting (23) said data packets on said first and second frequency bands, said selected packet and said one or more specific preambles, before said selected packet, on said second frequency band.

2. Transmission method according to claim 1, characterized in that said selecting step comprises a first substep of selecting a set of at least one data packet among said data packets to be transmitted to the destination. least a second destination equipment, taking into account the duration of transmission of the packets and the capacity of said at least one second destination equipment to receive data packets on said second frequency band.

A transmission method according to claim 2, characterized in that said selecting step comprises a second substep of selecting a data packet in said set, delivering said selected packet,

said second substep selection taking into account at least one of the criteria belonging to the group comprising:

a priority criterion taking into account the data type of said packet;

a transmission duration of said data packet for a predetermined transmission rate.

4. Transmission method according to claim 1, characterized in that it comprises a step of generating at least one preamble specific to data packets for said first destination equipment, the one or more specific preambles comprising at least one simultaneous transmission indicator on said first and second frequency bands, and in that said transmitting step transmits said specific preamble or preambles, before said packets, on said first frequency band.

5. Transmission method according to any one of claims 1 to 4, characterized in that said specific preamble further comprises at least one indicator belonging to the group comprising:

command indicator of the simultaneous transmission;

an indicator of said radio frequency channel (s) composing said second frequency band;

an indicator of said radio frequency channel (s) composing said first frequency band;

indicator of said at least one second recipient equipment;

indicator of said first destination equipment.

6. Transmission method according to claim 1, characterized in that said first and second acquisition and reservation steps implement:

listening to one of said radiofrequency channels composing said first frequency band, denoted primary channel, for a predetermined duration, and

listening to the other radio frequency channels of said concatenated channel for a duration equal to an interframe for access controlled by a transmission equipment, denoted PIFS, having an end coinciding with the end of said predetermined duration.

7. Transmission method according to claim 1, characterized in that it comprises a step of receiving, on at least one of said radiofrequency channels comprising said first frequency band, denoted primary channel, acknowledgments associated with said packets transmitted simultaneously on said first and second frequency bands.

8. Equipment for transmitting data packets in a communication network using a plurality of radio frequency channels,

first means for acquiring and reserving at least one of said radiofrequency channels of said concatenated channel, reserving a first frequency band for transmission of data packets to a first destination equipment; second means for acquiring and reserving the radio frequency channels of said concatenated channel not reserved by said first acquisition and reservation means, reserving a second frequency band for transmitting data packets to at least one second piece of equipment recipient ;

means for simultaneously transmitting said data packets on said first and second frequency bands.

9. A method of receiving data packets in a communication network using a plurality of radio frequency channels,

a step of receiving (61) data packets transmitted simultaneously on a first and a second frequency band, said first frequency band being formed of at least one of said radio frequency channels of said concatenated channel and said second frequency band consisting of other radio frequency channels of said concatenated channel;

a decoding step (631, 632) of data packets transmitted on only one of said first and second frequency bands as a function of the signaling received on at least one of said first and second frequency bands.

10. Reception method according to claim 9, characterized in that it comprises a step of receiving at least one specific preamble transmitted on said first and / or said second frequency band (s),

and in that said decoding step is implemented either on the packets transmitted on said first frequency band, or on the packets transmitted on said second frequency band, as a function of at least one simultaneous transmission indicator present in the specific preamble or preambles.

11. Reception method according to claim 9, characterized in that it comprises a step of transmitting, on one of said radio frequency channels composing said first frequency band, denoted primary channel, a reception acknowledgment of a transmitted packet. on said second frequency band,

said step of transmitting an acknowledgment being implemented after detecting a reception acknowledgment of a transmitted packet simultaneously on said first frequency band.

Receiver equipment for receiving data packets in a communication network using a plurality of radio frequency channels,

means for receiving data packets transmitted simultaneously on a first and a second frequency band, said first frequency band being formed of at least one of said radiofrequency channels of said concatenated channel and said second frequency band being formed of the radiofrequency channels; said concatenated channel not reserved; means for decoding data packets transmitted on only one of said first and second frequency bands as a function of the signaling received on at least one of said first and second frequency bands.

13. Multicarrier signal transmitted in a communication network using a plurality of radiofrequency channels, at least two of said radiofrequency channels being concatenated to form a concatenated channel,

characterized in that it carries data to a first destination equipment on carriers belonging to a first frequency band and data to a second destination equipment on carriers belonging to a second frequency band, said first frequency band being formed of at least one of said radiofrequency channels of said concatenated channel and said second frequency band being formed of the other radiofrequency channels of said concatenated channel.

14. A computer program comprising instructions for carrying out a method according to claim 1 or claim 9 when the program is executed by a processor.