阅读说明：本技术 用于扩展Wi-Fi接入点的覆盖范围的中继设备和系统 (Relay device and system for extending coverage of Wi-Fi access point ) 是由 V.吉列特 P.卢卡斯 R.祖亚奥伊 于 2019-12-17 设计创作，主要内容包括：本发明涉及一种用于中继由接入点(10)发送的Wi-Fi信号的设备(12)和一种用于扩展Wi-Fi接入点的覆盖范围的系统。本发明包括这种中继设备(12)以及用于扩展(11)Wi-Fi接入点(10)的设备。所述用于中继所述Wi-Fi信号的设备(12)包括：用于经由连接到用于扩展Wi-Fi接入点(10)的设备(11)的有线连接(13)来接收数字信号(S′)的部件(121),所述数字信号(S′)是通过对来自旨在要由所述Wi-Fi接入点在预定频率载波周围发送的信号(s)的功率划分的模拟信号(s′)进行模数转换以便传送第一Wi-Fi信号而得到的,数模转换部件(122),被配置为将经由所述有线连接接收的数字信号(S′)转换为模拟信号(s″),以及无线电重传部件(123、124、125),被配置为在所述预定频率载波周围发送由所述数模转换部件(122)提供的模拟信号(s″),以便传送与所述第一Wi-Fi信号基本相同的第二Wi-Fi信号。(The invention relates to a device (12) for relaying Wi-Fi signals transmitted by an access point (10) and a system for extending the coverage of a Wi-Fi access point. The invention includes such a relay device (12) and a device for extending (11) a Wi-Fi access point (10). The device (12) for relaying the Wi-Fi signal comprises: means (121) for receiving a digital signal (S') via a wired connection (13) to a device (11) for extending a Wi-Fi access point (10), the digital signal (S ') being obtained by analog-to-digital conversion of an analog signal (S') from a power division of a signal (S) intended to be transmitted by the Wi-Fi access point around a predetermined frequency carrier, in order to transmit a first Wi-Fi signal, a digital-to-analog conversion component (122) configured to convert a digital signal (S ') received via the wired connection into an analog signal (S'), and a radio retransmission part (123, 124, 125) configured to transmit an analog signal (s') provided by the digital-to-analog conversion part (122) around the predetermined frequency carrier, so as to transmit a second Wi-Fi signal that is substantially identical to the first Wi-Fi signal.)

1. A Wi-Fi signal relay device (12) comprising:

-means (121) for receiving a digital signal (S ') via a wired connection (13), said wired connection (13) being connected to a device (11) for extending a Wi-Fi access point (10), said digital signal (S ') being obtained by analog-to-digital conversion of an analog signal (S ') from a power division of a signal (S) intended to be transmitted by said Wi-Fi access point around a predetermined frequency carrier in order to transmit a first Wi-Fi signal;

a digital-to-analog conversion section (122) configured to convert a digital signal (S ') received via the wired connection into an analog signal (S'); and

-a radio retransmission unit (123, 124, 125) configured to send an analog signal (s ") provided by said digital-to-analog conversion unit (122) around said predetermined frequency carrier, so as to transmit a second Wi-Fi signal substantially identical to said first Wi-Fi signal.

2. The relay device of claim 1, wherein:

the receiving means (121) are configured to also receive, from an extension device, a control signal (c) of a signal obtained by the extension device from the Wi-Fi access point intended to be transmitted by the Wi-Fi access point;

the radio retransmission component (123, 124, 125) is configured to transmit the analog signal (s') taking into account the control signal (c).

3. The relay device of any of claims 1 or 2, further comprising: -means (125) for radio reception of a third Wi-Fi signal and-means (121) for sending said received third Wi-Fi signal to an expansion device (11) via said wired connection (13).

4. The relay device of claim 3, wherein the third Wi-Fi signal comprises a piece of information indicative of a use of at least one transmission channel.

5. The relay device according to any of claims 1 to 4, wherein the Wi-Fi access point (10) comprises a plurality of antennas intended to transmit the signal(s) around the predetermined frequency carrier, and the radio retransmission means (123, 124, 125) comprises a plurality of antennas configured to transmit the analog signal (s ") around the predetermined frequency carrier.

6. A system for extending the coverage of a Wi-Fi access point (10), comprising an extension device (11) and at least one relay device (12) according to any one of claims 1 to 5, the extension device (11) comprising:

an analog-to-digital conversion component (111) configured to convert power-divided analog signals (S ') from signals (S) to be transmitted by the Wi-Fi access point around a predetermined frequency carrier into digital signals (S') in order to transmit first Wi-Fi signals; and

means (112) for transmitting the digital signal (S') to the at least one relay device (12) via a wired connection (13),

the at least one relay device (12) is configured to send an analog signal (S ') around the predetermined frequency carrier, said analog signal (S ') resulting from a digital-to-analog conversion of a digital signal (S ') received from the expansion device (11), in order to transmit a second Wi-Fi signal substantially identical to the first Wi-Fi signal.

7. The expansion system according to claim 6, wherein the expansion device (11) is further configured to:

obtaining, from the Wi-Fi access point (10), a control signal (c) of a signal(s) intended to be transmitted by the Wi-Fi access point around the predetermined frequency carrier; and

-sending the control signal (c) to the relay device (12).

8. The expansion system of any one of claims 6 or 7, wherein:

the relay device (12) further comprises means (125) for radio reception of a third Wi-Fi signal around a predetermined frequency carrier, and means (121) for transmitting the received third Wi-Fi signal to the extension device (11) via the wired connection (13);

the extension device (11) further comprises means (112) for receiving the third signal transmitted by the relay device via the wired connection (13); and

the Wi-Fi module (15) of the Wi-Fi access point (10) comprises means for summing a fourth Wi-Fi signal received from a terminal around the predetermined frequency carrier and the third signal received from the relay device in order to transmit a signal to be decoded by a Wi-Fi encoding/decoding circuit (101) of the Wi-Fi access point.

9. The expansion system of claim 8 wherein:

the third signal received from the relay device includes a piece of information indicating the use of at least one transmission channel; and

the Wi-Fi access point is configured to use the piece of information in selecting a transmission channel for transmitting Wi-Fi signals.

10. The extension system according to any one of claims 6 to 9, wherein the extension device obtains the analog signal (s'):

-on a link between a Wi-Fi encoding/decoding component (101) of the Wi-Fi module of the Wi-Fi access point and a radio frequency integrated circuit (102); or

-when the Wi-Fi access point comprises at least one front-end module (103), the at least one front-end module (103) is connected to at least one antenna (104), the at least one antenna (104) being intended to transmit the first Wi-Fi signal from each of the at least one antenna (104) or from each of the at least one front-end module (103) input signals.

11. The extension system of any one of claims 6 to 10, wherein the first Wi-Fi signal transmitted by the Wi-Fi access point and the second Wi-Fi signal transmitted by the relay device are transmitted according to an OFDM radio technology type.

12. The extension system of any one of claims 6 to 11, wherein the relay device and/or the extension device comprises an offset module to offset the second Wi-Fi signal compared to the first Wi-Fi signal.

13. A method for transmitting, by a relay device (12), Wi-Fi signals of a Wi-Fi access point, the method comprising the steps of:

obtaining (E43), via a wired connection (13) to a device (11) for extending a Wi-Fi access point (10), a digital signal (S '), said digital signal (S ') being obtained by analog-to-digital converting a power-divided analog signal (S ') from a signal (S) intended to be transmitted by the Wi-Fi access point around a predetermined frequency carrier, in order to transmit a first Wi-Fi signal;

-converting (E44) a digital signal (S') received via said wired connection into an analog signal (S "); and

-sending (E45) an analog signal (s ") resulting from the conversion of the received digital signal around the predetermined frequency carrier, so as to transmit a second Wi-Fi signal substantially identical to the first Wi-Fi signal.

14. The transmission method of claim 13, further comprising: receiving, from the extension device, a control signal (c) of the signal(s) intended to be transmitted by the Wi-Fi access point, the transmission of the analog signal (s ") taking into account the control signal (c).

15. The transmission method according to any one of claims 13 or 14, further comprising: -transmitting (E40), by the Wi-Fi access point, the first Wi-Fi signal, adding an offset between the second Wi-Fi signal and the first Wi-Fi signal before transmitting an analog signal (S ") resulting from the conversion of the received digital signal (S").

Technical Field

The present invention relates to an apparatus for increasing Wi-Fi coverage of a Wi-Fi access point.

Background

Wi-Fi coverage performance issues are one of the main complaints of residential or commercial (SME) internet service subscribers. Such problems may arise from a variety of reasons, including interference or lack of sufficient Wi-Fi signal levels being received, for example when a Wi-Fi access point (typically a residential gateway) is too far away or when there is an obstruction, such as a thick wall or equipment interfering with the Wi-Fi signal.

To increase the Wi-Fi coverage of a Wi-Fi access point, a device called a "Wi-Fi extender" may be placed in the environment to be covered, for example, in a position where the Wi-Fi signal of the access point is zero.

Such a "Wi-Fi extender" operates in a similar manner to the main Wi-Fi access point of the environment. A terminal that wants to have a Wi-Fi connection must select and associate with a Wi-Fi access point from among the available access points, residential gateways or "Wi-Fi extenders". However, client terminals do not necessarily support well managing multiple Wi-Fi access points to associate therewith.

Furthermore, the use of such "Wi-Fi extenders" can be tedious, as they require complex "handoff" mechanisms to be implemented between two Wi-Fi access points (e.g., as the terminal moves around the environment) to force the Wi-Fi terminal to select the access point that provides the best Wi-Fi signal, as the Wi-Fi terminal can only communicate with one Wi-Fi access point at a given time. Wi-Fi client terminals do not always properly support these handover mechanisms.

International application WO2004/045125 proposes a home wireless network system in which a splitting module is located between an access point and its antenna so as to couple directly, at a distance from the access point, a portion of the signal intended for the antenna (without coupling a control signal related to the signal to be transmitted) to a wired extension which is itself connected to an extension module responsible for transmitting the portion of the signal.

However, due to the spectral characteristics of the signals it has to transmit, this system requires the specific use of wired extensions, such as coaxial cables, in order to be able to transmit the radio signals as such by means of an analog form of transmission of the "cable radio" type. In particular, if the access point transmits signals at a 5GHz frequency, the signals transmitted over the cable will also be at that 5GHz frequency, requiring a coaxial cable having the required bandwidth to carry such radio signals. Thus, the system requires the presence of pre-existing coaxial cables or the laying of new coaxial cables to connect the expansion module to the access point, which is inconvenient and can be expensive.

Furthermore, this prior art system only aims at extending the coverage of a single antenna access point and is difficult to transform to a multi-antenna access point (i.e. MIMO type), since such a transformation would mean connecting each antenna of the multi-antenna access point to each antenna of the multi-antenna extension module with a dedicated coaxial cable.

Disclosure of Invention

The present invention improves upon the prior art.

To this end, the present invention proposes a Wi-Fi signal relay device including:

means for receiving a digital signal via a wired connection to a device for extending a Wi-Fi access point, the digital signal resulting from analog-to-digital converting a first Wi-Fi signal to be transmitted from a power-divided analog signal intended for signals to be transmitted by the Wi-Fi access point around a predetermined frequency carrier;

a digital-to-analog conversion section configured to convert a digital signal received via the wired connection into an analog signal; and

a radio retransmission component configured to transmit the analog signal provided by the digital-to-analog conversion component around the predetermined frequency carrier so as to transmit a second Wi-Fi signal substantially identical to the first Wi-Fi signal.

Relatedly, the invention also relates to a system for extending the coverage of a Wi-Fi access point, comprising an extension device as described above and at least one relay device, said extension device comprising analog-to-digital conversion means configured to convert power-divided analog signals from signals to be transmitted by said Wi-Fi access point around a predetermined frequency carrier into digital signals in order to transmit a first Wi-Fi signal; and means for transmitting the digital signal to the at least one relay device via a wired connection,

the at least one relay device is configured to transmit an analog signal around the predetermined frequency carrier to convey a second Wi-Fi signal substantially identical to the first Wi-Fi signal, the analog signal resulting from digital-to-analog conversion of a digital signal received from the extension device.

According to the present invention, a device for relaying Wi-Fi signals and a Wi-Fi coverage extension system are proposed. Such a system includes a device for relaying Wi-Fi signals transmitted by a Wi-Fi access point and at least one device for extending the Wi-Fi access point, which may be included in the Wi-Fi access point.

These devices may extend the Wi-Fi coverage of a Wi-Fi access point without suffering from the disadvantages of the prior art, particularly by identically relaying Wi-Fi signals transmitted by the Wi-Fi access point with a slight offset, without being limited to the use of a coaxial cable between the Wi-Fi access point and the extension device.

From the point of view of the Wi-Fi client terminal, it receives a combination of two Wi-Fi signals: a first Wi-Fi signal sent by a Wi-Fi access point and a second Wi-Fi signal sent by a relay device (or more if there are several relay devices), each Wi-Fi signal having propagated on its own multipath propagation channel.

Advantageously, the relay device is not a Wi-Fi access point. Thus, a Wi-Fi terminal treats a Wi-Fi network extended with Wi-Fi repeaters as originating from a single Wi-Fi access point. Problems due to selection of Wi-Fi access points or handover between Wi-Fi access points are avoided.

Furthermore, the relay device does not need a Wi-Fi encoding/decoding module, since the received signal to be retransmitted has been encoded according to the Wi-Fi standard. The relay device operates on the radio/physical layer level.

The first Wi-Fi signal transmitted by the Wi-Fi access point and the second Wi-Fi signal transmitted by the repeater are substantially identical. This means that both signals use the same frequency carrier to transmit the same data on the same channel. The signal is transmitted using the same modulation scheme, e.g., based on OFDM modulation. Therefore, the two signals have the same waveform. The only possible differences are differences in power, since the tapped (tapped) signal sent by the relay device comes from the power division of the signal to be sent by the Wi-Fi access point, then possibly amplified (within regulatory ERIP (equivalent isotropic radiated power) limits) before being sent by the antenna system of the relay device, and slight shifts, in particular due to the transmission time of the tapped signal to the relay device.

According to a particular embodiment of the invention, the receiving means of the relay device are also configured to receive from the extension device a signal control of a signal obtained by the extension device from the Wi-Fi access point intended to be transmitted by said Wi-Fi access point, the radio retransmission means of the relay device being configured to transmit the analog signal provided by the digital-to-analog conversion means taking into account said control signal.

In particular, the control signal may be retrieved in analog form at the access point and then converted to digital form by the extension device before being sent to the relay device via the wired connection, where the control signal may be converted to analog form by a digital-to-analog conversion component of the relay device.

This control signal, which is typically transmitted by the Wi-Fi encoding/decoding circuitry of the Wi-Fi access point, may specifically include information (e.g., the channel number and bandwidth of the Wi-Fi signal) used by the radio transmission component of the Wi-Fi module of the access point to transmit the first Wi-Fi signal. The retransmission component of the relay device then takes into account this control signal (in particular the information it contains) to send the analog signal provided by the digital-to-analog conversion component, so as to transmit the second Wi-Fi signal.

The above-described retrieval of the control signal by the relay device allows the relay device to have information about the transmission characteristics of the first Wi-Fi signal and thus better ensure similarity of transmission characteristics between the first and second Wi-Fi signals, although the signal tapped at the access point has undergone an analog-to-digital conversion and then a digital-to-analog conversion before reaching the relay device, which may result in loss of this information.

Relatedly, according to this particular embodiment of the invention, the extension device is configured to obtain from a Wi-Fi access point (in particular from Wi-Fi encoding/decoding circuitry of this access point) control signals intended for signals transmitted by said Wi-Fi access point around said predetermined frequency carrier, and to transmit said control signals to said relay device.

According to another particular embodiment of the invention, the relay device further comprises means for radio reception of a third Wi-Fi signal around a predetermined frequency carrier, and means for sending said received third Wi-Fi signal to said extension device via said wired connection. Relatedly, according to this other particular embodiment of the invention, the extension device of the extension system further comprises means for receiving said third signal transmitted by the relay device via said wired connection, and the Wi-Fi module of the Wi-Fi access point comprises means for summing a fourth Wi-Fi signal received from the terminal around said predetermined frequency carrier and the third signal received from the relay device to transmit a signal to be decoded by the Wi-Fi encoding/decoding circuit of the Wi-Fi access point.

According to this particular embodiment of the invention, when Wi-Fi signals transmitted by the terminal around the predetermined frequency carrier are received by both the antenna of the Wi-Fi access point and the antenna of the relay device associated therewith, the two received Wi-Fi signals are summed before being decoded by the Wi-Fi encoding/decoding circuit of the Wi-Fi access point.

According to another particular embodiment of the invention, when the relay device operates in the reception mode, the third Wi-Fi signal received by the relay device comprises a piece of information representative of the use of at least one transmission channel. Relatedly, in extended systems, Wi-Fi access points are configured to use this information in selecting a transmission channel for transmitting Wi-Fi signals.

In accordance with this particular embodiment of the invention, in the receive mode, the relay device may monitor the SSIDs/RSSIs of other Wi-Fi access points in the environment and feed this information back to the Wi-Fi access point with which it is associated. For example, the relay device receives a "beacon" signal indicating that the Wi-Fi channel is used. In this way, a Wi-Fi access point associated with a relay device may optimize the selection of a transmission channel for transmitting Wi-Fi signals because it obtains channel usage information from different locations in the environment (i.e., where the relay device is placed).

According to another particular embodiment of the invention, the Wi-Fi access point comprises a plurality of antennas intended to transmit signals around said predetermined frequency carrier, and the radio retransmission component of the relay device comprises a plurality of antennas configured to transmit analogue signals around said predetermined frequency carrier.

This embodiment is intended to extend the Wi-Fi coverage of a multi-antenna access point type (i.e. using, for example, MIMO transmission/reception technology), which is particularly advantageous by the present invention, since it allows to extend this coverage by using a single wired transmission hardware medium (for example, a single ethernet cable, a single optical fibre, etc.) between the access point and the relay device (even if these are of the multi-antenna type).

According to another particular embodiment of the invention, the extension device obtains the analog signal at a link between a Wi-Fi encoding/decoding component of the Wi-Fi module of the Wi-Fi access point and a radio frequency integrated circuit of the Wi-Fi access point. According to this particular embodiment of the invention, the signal to be identically retransmitted by the relay module is obtained just after the MAC/BB Wi-Fi chipset of the Wi-Fi access point (i.e. the module for encoding/decoding the signal to be transmitted or received according to the Wi-Fi standard) before the Wi-Fi signal is provided to the RFIC module of the Wi-Fi access point.

According to another particular embodiment of the invention, the Wi-Fi access point comprises at least one front-end module connected to at least one antenna intended to transmit the first Wi-Fi signal, and the expansion device is configured to obtain the analog signal from the input signal of each of said at least one antenna or each of said at least one front-end module.

According to this particular embodiment of the invention, the signals to be identically retransmitted by the relay module are obtained at the antennas of the Wi-Fi access point or at the upstream front-end module, in particular in case of transmission in MIMO mode, through several antennas. This embodiment provides the advantage that the RFIC circuit of the relay device is standard. It need not be the same as the RFIC circuit of the Wi-Fi access point. Accordingly, the RFIC circuit may be simpler because it is essentially a frequency translation module that does not require a priori knowledge of the signal formatting.

According to another particular embodiment of the invention, the first Wi-Fi signal transmitted by the Wi-Fi access point and the second Wi-Fi signal transmitted by the relay device are transmitted according to an OFDM radio technology.

According to another particular embodiment of the invention, the relay device and/or the extension device comprise an offset module for offsetting said second Wi-Fi signal compared to said first Wi-Fi signal. In this particular embodiment of the invention, the same signal is transmitted at two different locations (but not simultaneously), thereby increasing the space-time diversity of the multipaths of the radio signal. Radio transmission techniques using multipath of radio signals (e.g. OFDM) are even more powerful.

The invention also relates to a method for transmitting Wi-Fi signals of a Wi-Fi access point by a relay device, said method comprising the steps of:

obtaining, via a wired connection to a device for extending a Wi-Fi access point, a digital signal obtained by analog-to-digital converting a power-divided analog signal from a signal intended to be transmitted by the Wi-Fi access point around a predetermined frequency carrier in order to transmit a first Wi-Fi signal;

converting a digital signal received via the wired connection to an analog signal; and

sending an analog signal resulting from conversion of the received digital signal around the predetermined frequency carrier to transmit a second Wi-Fi signal substantially identical to the first Wi-Fi signal.

According to one embodiment, the method further comprises receiving, from the expansion device, a control signal intended for the signal to be sent by said Wi-Fi access point, the transmission of the analog signal taking into account said control signal.

According to another embodiment, the method further comprises transmitting, by the Wi-Fi access point, a first Wi-Fi signal, wherein an offset is added between the second Wi-Fi signal and the first Wi-Fi signal before transmitting an analog signal resulting from the conversion of the received digital signal.

The invention also relates to a method for receiving Wi-Fi signals by a Wi-Fi access point via a wide area Wi-Fi network, comprising the steps of:

radio reception of a first Wi-Fi signal by a relay device around a predetermined frequency carrier,

transmitting the received signal to an extension device of the Wi-Fi access point via a wired connection connecting the relay device and the extension device,

radio receiving, by the Wi-Fi module of the Wi-Fi access point, around the predetermined frequency carrier of a second Wi-Fi signal,

summing a second Wi-Fi signal received by a Wi-Fi module of a Wi-Fi access point with the first Wi-Fi signal received from a relay device to transmit a signal to be decoded, an

The signal to be decoded is sent to the Wi-Fi encoding/decoding circuitry of the Wi-Fi access point.

According to a particular embodiment of the invention, the first Wi-Fi signal comprises a piece of information representative of the use of at least one transmission channel.

Drawings

Other characteristics and advantages of the invention will emerge more clearly on reading the following description of a particular embodiment, provided as a simple non-limiting illustrative example, and the attached drawings, in which:

figure 1 illustrates a system for extending the coverage of a Wi-Fi access point according to a particular embodiment of the invention,

figure 2 illustrates an arrangement of elements of a system for extending the coverage of a Wi-Fi access point according to a particular embodiment of the invention,

figure 3 illustrates the arrangement of elements of a system for extending the coverage of a Wi-Fi access point according to another particular embodiment of the invention,

figure 4 illustrates the steps of a method for transmitting a Wi-Fi signal of a Wi-Fi access point, according to a particular embodiment of the invention, and

figure 5 illustrates the steps of a method for receiving Wi-Fi signals of a Wi-Fi access point, according to a particular embodiment of the invention.

Detailed Description

The present invention proposes a new solution for extending the Wi-Fi coverage of a Wi-Fi access point, which does not have the drawbacks of the prior art.

Figure 1 illustrates a system for extending the coverage of a Wi-Fi access point, in accordance with certain embodiments of the present invention.

Such a system comprises a Wi-Fi access point (10), for example a home gateway located in the home of a user of a subscription operator, or an internet access gateway of a company of a subscription communication operator, the Wi-Fi access point (10) comprising a Wi-Fi module 15(Wi-Fi chipset), the Wi-Fi module 15 being configured to enable sending and receiving Wi-Fi signals to and from a Wi-Fi terminal associated with the access point (10). In other words, the Wi-Fi module (15) is an element of the access point (10) that implements communication protocols at the physical layer and the MAC layer according to the IEEE standard used (mainly 802.11 abg/n/ac/ax/ad/ay/be).

The signals transmitted by the Wi-Fi access points (10) may use OFDM modulation types, and in particular OFDMA multiple access technology types, but the invention is not limited to these types of access or modulation techniques.

The access point (10) typically also includes other modules (processor, memory, etc.) necessary for its operation and other information transfer layer applications. These conventional elements are not necessary for an understanding of the present invention and they are not shown in fig. 1.

The system shown in fig. 1 also comprises an expansion device (11), which expansion device (11) is advantageously integrated in the Wi-Fi access point (10), but can also be connected to the Wi-Fi access point (10) without integration. The extension device (11) is configured to retrieve an analog signal intended to be transmitted by a Wi-Fi module (15) of the access point (10).

The system shown in fig. 1 also includes a relay device (12), which is a remote radio module that similarly relays Wi-Fi signals transmitted by the Wi-Fi access point (10).

For this purpose, the expansion device (11) and the relay device (12) are connected by a wired medium (13) such as a coaxial cable, an optical fiber or an ethernet cable. The wired medium (13) may also be of the powerline type, i.e. a cable within a home power network, to supply power to a wall outlet.

Wi-Fi signals retrieved by the extension device (11) are sent to the relay device (12) via the wired medium (13), which the relay device (12) relays identically to the Wi-Fi access point.

Thus, the system for extending Wi-Fi coverage presented herein extends the radio coverage of a Wi-Fi Access Point (AP) by relaying Wi-Fi signals of the Wi-Fi access point remotely with a slight offset.

This principle consists in tapping a portion of the power of the signal intended to be transmitted by the Wi-Fi module of the Wi-Fi access point, in the baseband or around its frequency carrier, to retransmit it further and equally using one or more remote radio modules (hereinafter also referred to as relay devices).

The same retransmission means that the relay device uses the same channel, the same modulation (MCS, bandwidth, number of spatial streams, etc.), the same data as the Wi-Fi access point, but with a slight offset. Thus, the Wi-Fi access point and the relay device transmit a first Wi-Fi signal and a substantially identical second Wi-Fi signal, respectively.

The offset can be generated naturally by inserting the processing time of the different components in the extension (11) and relay (12) devices and by the travel time in the wired medium (13).

According to a particular embodiment of the invention, if the offset is too short with respect to the guard interval of the OFDM modulation used by the Wi-Fi access point, a particular delay may be added to the signal tapped by a dedicated component (e.g., a delay line) that may be incorporated into either of the extension device and the relay device.

This technique can be viewed as a combination of spatial and temporal macro diversity.

The Wi-Fi client station or Wi-Fi client terminal (14 in fig. 1) eventually receives a combination of two (or more) radio signals WF1, WF2, each having propagated on its own multipath propagation channel: a propagation channel for radio signal WF1 from a master Wi-Fi access point (10) and a propagation channel for radio signal WF2 from a remote radio module (relay device 12).

The channel information is communicated to the remote module (12) in a control signal (denoted as "c" in fig. 2 and 3 described later).

The channel is known or selected by the Wi-Fi access point (10) using a conventional selection algorithm. Typically, the channel is selected according to the power level of the SSID (service set identifier) seen on the Wi-Fi access point (10) side.

According to a particular embodiment of the invention, in the receive mode, the relay device (12) may feed back the RSSI power level of the SSID of the environment to the Wi-Fi access point (10). Thus, the Wi-Fi access point (10) may select a transmission channel taking this information into account when it wants to send Wi-Fi signals. For example, in the list of SSID power levels used by the Wi-Fi access point (10), there will also be a power level of the SSID seen on the relay device (12) side.

The principle is described below in the case of adding a single relay device, but the system can of course be generalized to several remote relay devices. In this case, each relay device would need to be wired to a Wi-Fi access point to obtain a Wi-Fi signal to retransmit.

If the frequency response of the signal transmitted by the Wi-Fi access point (10) in baseband is denoted S (F), the terminal (14) receives a signal consisting of a useful signal and noise, the useful signal corresponding to the product S (F-F0) x (H1(F-F0) + H2(F-F0)), where H1(F-F0) and H2(F-F0) represent the transfer functions of the multipath radio channels around the same frequency carrier F0 between the Wi-Fi access point (10) and the client terminal (14) and between the relay device (12) and the client terminal (14), respectively.

According to the prior art, with a conventional Wi-Fi extender, i.e. operating as a Wi-Fi access point, the terminal receives a signal consisting of a useful signal and noise, wherein the useful signal corresponds to the product S1(F-F0) xh 1(F-F0) or S ' 2(F-F1) xh 2(F-F1), wherein S1 corresponds to the frequency response of the signal sent by the main Wi-Fi access point and S ' 2 corresponds to the frequency response of the signal sent by the conventional Wi-Fi extender, and S1 and S ' 2 may be different, as well as the carrier frequency F0 of the main Wi-Fi access point and the carrier frequency F1 of the conventional Wi-Fi extender, which may also be different.

This may be particularly the cause of performance degradation according to the prior art, for example when a Wi-Fi terminal is held on the first master Wi-Fi access point using the received signal S1xH1, whereas the signal S' 2xH2 sent by a conventional Wi-Fi extender may provide a better bit rate. However, this is very difficult to expect when the Wi-Fi access point and Wi-Fi extender operate in MIMO (multiple input multiple output). Indeed, by doing so, better signal levels do not necessarily ensure better bit rates.

According to the invention, the system described in relation to fig. 1 can be extended by adding several remote radio modules or relay devices (12), depending on the size of the house in question. Furthermore, a remote radio module (12) can be added for each frequency band (2.4GHz, 5GHz, 60 GHz.) and technology (4G, 5 g..) that is considered useful. It is sufficient that all relay devices and Wi-Fi access points use the same radio transmission technology, e.g. OFDM (orthogonal frequency division multiplexing).

The system according to the invention also operates in the upstream direction, i.e. the signals received by the Wi-Fi access point (10) on the one hand and the remote radio module(s) (12) on the other hand are summed before being decoded by the Wi-Fi chipset (15) of the Wi-Fi access point (10). The upstream and downstream directions are separated by the standard system of duplexers.

The described principles for extending Wi-Fi radio coverage significantly improve the Wi-Fi radio coverage of an access point in terms of bit rate and range.

A Wi-Fi network established by an access point and its associated relay device(s) according to the invention is considered by a Wi-Fi terminal to be from a single access point. This eliminates the problem of switching or "client steering" between the master Wi-Fi access point and the conventional Wi-Fi extender (a technique that forces a Wi-Fi terminal to associate with an AP other than the one selected by its own Wi-Fi connection manager by default). Unlike prior art solutions using wired/Wi-Fi or Wi-Fi/Wi-Fi conventional Wi-Fi extenders, with the present invention, the terminal does not have to choose which Wi-Fi access point to associate with, because it only sees one Wi-Fi access point.

Initial pairing also becomes easier. In fact, the live pairing mechanism with the Wi-Fi access point is not changed, except that the Wi-Fi client terminal will be able to pair when placed further away. The same security key is maintained.

The principles for extending Wi-Fi radio coverage according to the present invention also allow saving spectrum by using the same channel in any coverage location with such a coverage extension system.

Thus, the selection of Wi-Fi channels is optimized, which according to the prior art is selected by a Wi-Fi access point by using the detected signal levels of neighboring Wi-Fi access points. According to a particular embodiment of the invention, the Wi-Fi access point will also access the signal levels of other neighboring Wi-Fi access points of the relay device(s).

According to the present invention, a Wi-Fi access point can maintain its algorithm by using SSID/RSSI (received signal strength indication) data seen at the Wi-Fi access point side as well as at the relay device(s) side. The selected channel is then preferably the best channel on the coverage area of the access point and relay device(s) associated therewith, and is no longer the best channel on the coverage area limited to Wi-Fi access points or conventional Wi-Fi extenders.

Thus, the channel selection is more "optimal" than prior art solutions, since interference information at several different locations in the residence is used for channel selection, not just local interference information at a single location where the master Wi-Fi access point is placed.

Figure 2 illustrates an arrangement of elements of a system for extending coverage of a Wi-Fi access point, according to a particular embodiment of the invention.

In fig. 2, only those elements of the Wi-Fi access point (10) are shown which are necessary for the present invention. Wi-Fi module (15) is shown here using the example of 3x3 MIMO transmission, however the principles of the invention extend to other types of MIMO transmission.

Conventionally, the Wi-Fi module (15) comprises a Wi-Fi coding/decoding (MAC/BB) module (101), a Radio Frequency (RFIC) circuit (102) and 3 FEM (front end module) modules (103), wherein the FEM modules in particular comprise a signal amplifier, a Low Noise Amplifier (LNA) and a duplexer for separating the upstream and downstream directions of the channel. The Wi-Fi module (15) shown in fig. 2 further comprises three antennas (104) connected to the three FEM modules, respectively.

According to the invention, the expansion device (11) comprises an analog-to-digital (A/D) converter (111) and a modulator-demodulator (112, modem) for adapting the signal to be transmitted to the wired medium used.

According to a particular embodiment described herein, the expansion device (11) obtains an analog signal (denoted "s" in fig. 2) tapped from the signal (denoted "s" in fig. 2 and shown in solid lines) to be transmitted by the Wi-Fi module (15). This signal s' is typically obtained at the link between the Wi-Fi encoding/decoding module (101) and the RFIC circuit (102). The signal s is an I/Q channel baseband OFDM signal from the MAC/BB encoder/decoder.

The tapping of a part of the signal is performed by adding a power splitter (110) between the MAC/BB and RFIC links and the a/D converter (111) of the extension device. Tapping is here understood to be a small percentage of the power of the tapped signal s. Thus, this tapping is done by dividing the power of signal s to transmit signal s'.

The extension device (11) also retrieves a control signal (denoted as "c" in fig. 2) intended to control the transmission of the signal s by the Wi-Fi module (15) by providing information (such as the channel number and bandwidth of the Wi-Fi signal) to the Radio Frequency (RFIC) circuit (102) and the FEM module (103). The control signal c is also typically in analog form, e.g. a 0V or 5V TTL signal.

The signals S 'and C are converted by a converter (111) into digital signals S' and C, which are sent to the relay device (12) via a modem (112) and a wired link (13). This may be used to adapt to bandwidth constraints of the medium used to transmit the signal s' in analog form, and hence to any limitations of the type of wired link used to comply with such constraints. Furthermore, the conversion of both the "useful" signal S 'and the control signal C into digital signals S' and C makes it possible to send both digital signals together over the wired link (13), or even to apply any suitable digital processing to them in order to optimize the transmission.

According to the invention, the relay device (12) comprises a modulator-demodulator (121, also called "modem") connected to a digital-to-analog conversion section (122), the digital-to-analog conversion section (122) itself being connected to a radio retransmission section. In particular, the digital-to-analog converting part (123) may be implemented as a digital-to-analog (D/a) converter. The retransmission component may be implemented in the form of an RFIC radio frequency circuit (123) connected to N (here as an example N-3) FEM (front end module) modules (124), wherein each FEM module (124) is connected to N antennas (125).

Thus, the relay device (12) receives the digital signals S ' and C via the wired link (13), the modulator-demodulator (121) demodulates these two signals S ' and C and then supplies them to the converter (122), and the converter (122) converts them into analog signals S "and C ', respectively. The analog signals s "and c' are then sent to the RFIC circuit (123) so as to send the same analog signal s" as signal s, but with a slight offset compared to the first Wi-Fi signal s sent by the Wi-Fi module (15). Possibly, the signal s "is amplified within the regulatory ERIP limits before being transmitted by the antenna system of the relay device.

In order to transmit the analog signal s ", the RFIC circuit (123) uses the control signal" c "received from the Wi-Fi access point, in particular the channel and modulation information it may contain.

According to the particular embodiment described herein, the RFIC circuit (123) is advantageously identical to the RFIC circuit (102) of the Wi-Fi module (15), so that the analog signal s "is distributed to the FEM module (124) and the antenna (125) of the relay device (12) in the same way as the signal s is distributed to the FEM module (103) and the antenna (104) of the Wi-Fi module (15).

Figure 3 illustrates an arrangement of elements of a system for extending coverage of a Wi-Fi access point, according to another particular embodiment of the invention. The elements in fig. 3 are almost identical to those shown in the figure. Only the tapping point of the signal s' is different.

According to this particular embodiment of the invention, the spreading device (11) taps the signal s' on the link between each FEM module (103) and each antenna (104). Alternatively, the signal s' may also be tapped by the expansion device (11) on the link between the RFIC circuit (102) and each FEM module (103).

The control signal "c" is tapped at a Wi-Fi (MAC/BB) encoding/decoding module (101).

Tapping of a portion of the signal s to convey a tapped signal s 'is performed by adding a power splitter (110) between each antenna (104) and its corresponding FEM module (103) or between the RFIC circuit (102) and each FEM module (103) in order to provide the tapped signal s' to an a/D converter (111) of the expansion device.

According to this particular embodiment of the invention, the signal is tapped before or after the FEM module (depending on the connector). A very small fraction of the transmit power is required. In practice, the a/D converter need not transmit 23 to 30dBm (0dBm or even less may be sufficient, i.e. 1/1000 less than the transmit power may be sufficient). The RFIC circuitry (123) of the relay device (12) is here more standard than in the particular embodiment described in relation to fig. 2 where the signals are tapped at baseband. Indeed, according to the particular embodiment described with respect to fig. 3, the RFIC circuit (123) is essentially a frequency translation module that does not require knowledge of the signal formatting.

Here, the signal s' tapped at the antenna or FEM has 3 dimensions (in case of 3x3 MIMO), which may be placed in series at the a/D converter or modem. This serialization is the purpose of the CPRI protocol or any other protocol that allows the signal s' to be sent to the relay device. The format/matching with the antenna is known here according to this particular embodiment of the invention.

The general principles of the present invention have been described herein with respect to signals to be transmitted by the Wi-Fi module of the access point (i.e., in the downstream direction). The elements described with respect to fig. 2 and 3 operate in a reciprocal manner in the upstream direction (Wi-Fi signals received by the antennas (104 and 125)).

The separation of the radio signal between the upstream and downstream directions requires a duplexer, typically this function is integrated in a "FEM" module. Similarly, the RFIC circuit must also be able to operate in both directions (frequency translation to the desired frequency in the downstream direction, translation to baseband in the upstream direction).

The a/D converter and modem must also operate in both directions, rather than simultaneously, because Wi-Fi cannot receive and transmit simultaneously.

In the upstream direction, signals received by the Wi-Fi module (15) of the access point and by the remote radio module(s) (relay device 12) are summed at the Wi-Fi module (15).

More precisely, the received signals are summed at the antenna or FEM module connector, for example in case of the embodiment described with respect to fig. 3.

In the case of the embodiment described with respect to fig. 2, the received signals are summed at the MAC/BB-RFIC link.

In the downstream direction, the signal is tapped by the power splitter, as described above. In the upstream direction, the signals are summed by the power coupler.

The same component may perform both functions (splitter/coupler) according to different embodiments.

In case the signal is tapped at the antenna or FEM, there is preferably one splitter/coupler per antenna or FEM connector.

Depending on the particular embodiment of the invention, a time delay may be added to signal s ' (as compared to signal s), or a time delay may be added to signal s ' (as compared to signal s '). This may be done, for example, using dedicated delay line type components (not shown in fig. 2 or 3).

Thus, an offset is added to the second Wi-Fi signal transmitted by the relay device compared to the first Wi-Fi signal transmitted by the Wi-Fi access point, and vice versa, depending on the implementation variant chosen. Such delays may be added in transmission and reception.

The Wi-Fi standard defines several interval values, called guard intervals, according to the standard used: for example, in 802.11n/ac, 2 values are possible: 400ns or 800 ns.

The spacing is selected to absorb the multipath related delays of the propagation channel and optimize OFDM performance. In particular, the more multipath present (with delay spread within the guard interval limit), the better the OFDM performance will be. In other words, a better bit rate can be obtained for the same received power level.

For example, in the case of a Wi-Fi access point implemented by a home gateway, the delay to be added may thus be, for example, 100ns, based on a guard interval of 400ns according to the 802.11n/ac standard, for Wi-Fi communication inside the home, without the risk of exceeding the tolerance of the system to multipath.

Different embodiment variations may add this delay depending on the performance of the electronic components added to implement the invention.

According to a first variant, if the processing time T (ns) of the spreading module and the power division is very fast (e.g., <100ns), an additional delay (100-T) is added at the relay device.

According to a second variant, if the processing time of the extension module and of the power division is "relatively high" (for example, of the order of a few microseconds (denoted x)), then in this case a delay is added at the Wi-Fi access point when the signal is tapped on the channel of the signal s intended to be transmitted by the Wi-Fi access point. The delay is then x microseconds to 100ns to have an offset of 100ns between a first Wi-Fi signal transmitted by the Wi-Fi access point and a second Wi-Fi signal transmitted by the relay device.

Figure 4 illustrates steps of a method for transmitting a Wi-Fi signal of a Wi-Fi access point by a relay device, in accordance with a particular embodiment of the present invention.

At step E40, the Wi-Fi access point (10) transmits a first Wi-Fi signal from the analog signal s around a predetermined frequency carrier. The predetermined frequency carrier corresponds to, for example, a frequency associated with a transmission channel selected by a Wi-Fi access point.

At step E41, the extension device (11) of the Wi-Fi access point (10) obtains from the Wi-Fi module (15) of the Wi-Fi access point an analog signal s' corresponding to a portion of the signal s transmitted in step E40, and possibly a control signal c intended to control the transmission of the signal s by the Wi-Fi access point. The obtaining step E41 may be implemented after step E40 or simultaneously with step E40.

In step E42, the expansion device (11) converts the analog signal S 'obtained in step E41 into a digital signal S'. If the control signal C is obtained in step E41, it may also convert the control signal C into a control digital signal C during the same step.

In step E43, the expansion device (11) sends the digital signal S' (and possibly the control digital signal C) to a relay device (12) connected to the expansion device via a wired connection (13).

After receiving the digital signal S ', the relay device (12) converts the digital signal S' into an analog signal S ″ that it intends to transmit, step E44. If the control digital signal C is obtained in step E43, it may also convert the control digital signal C into a control analog signal at that time.

In step E45, the relay apparatus (12) transmits the analog signal s ″ resulting from the conversion performed in step E42' by radio waves around the predetermined frequency carrier. The radio signal transmission is done in substantially the same way as Wi-Fi signal transmission performed by a Wi-Fi module (15) of a Wi-Fi access point. In other words, the same frequency carrier is used, and therefore the same channel and the same modulation.

Figure 5 illustrates steps of a method for receiving Wi-Fi signals of a Wi-Fi access point, in accordance with certain embodiments of the present invention.

At step E50, the relay device (12) receives Wi-Fi signals via its radio antenna around a predetermined frequency carrier. Such Wi-Fi signals may have been sent by a terminal in communication with a Wi-Fi access point or by another Wi-Fi access point. For example, in this case, the Wi-Fi signal corresponds to a "beacon" frame from the Wi-Fi access point that includes SSID information segments of the Wi-Fi access point associated with RSSI levels of channels used by the Wi-Fi access point. Such information thus corresponds to a piece of information about the use of the transmission channel.

At step E51, the relay device (12) converts the received analog signal to a digital signal and transmits the digital signal to the extension device (11) of the Wi-Fi access point via a wired connection (13) connecting the relay device and the extension device (step E52).

At step E53, the expansion device converts the digital signal from the relay device to an analog signal and then provides the analog signal to the Wi-Fi module (15) of the Wi-Fi access point.

At step E54, Wi-Fi module (15) may receive Wi-Fi signals around the same predetermined frequency carrier via antenna 104 of Wi-Fi module (15). The Wi-Fi signal may originate from the terminal or another Wi-Fi access point.

At step E55, the signal received by the Wi-Fi module (15) of the Wi-Fi access point and the signal from the relay device (12) provided by the extension device (11) are summed in the Wi-Fi access point to transmit a Wi-Fi signal to be decoded.

At step E56, the Wi-Fi signal to be decoded is sent to the Wi-Fi encoding/decoding circuitry (101) of the Wi-Fi access point.

According to a particular embodiment of the invention, the decoded Wi-Fi signal is a "beacon" frame of another Wi-Fi access point. It therefore comprises a piece of information representative of the use by the other Wi-Fi access point of the transmission channel associated with said predetermined frequency carrier. Such a piece of information is then fed back to the software module of the Wi-Fi access point, which implements the channel selection algorithm for data transmission. Thus, the channel selection algorithm implemented by the Wi-Fi access point is optimized because it benefits from the channel usage information available at the remote relay device associated therewith.

Methods for transmitting and receiving Wi-Fi signals in an extended Wi-Fi network via the above-described system for extending Wi-Fi coverage add time diversity to the channel by adding an offset to the transmission time of the remote access point and radio module. This diversity is beneficial for OFDM performance as long as the delay between transmissions remains within the guard interval limits of the system.

Furthermore, Wi-Fi coverage is extended at the pure radio level, and therefore there are no software upgrade constraints.

In order to connect the extension device to the Wi-Fi module of the Wi-Fi access point, an appropriate connector is required to tap the signal to be relayed and the synchronization signal/command (signal "c" in fig. 2 and 3).

Depending on the embodiment considered, this may be complex in the context of increasing integration of radio functions and disappearance of connectors on new Wi-Fi chipsets, especially for embodiments based on baseband signal tapping (fig. 2). This is why for this particular embodiment the cooperation between the chipset manufacturer and the industry/integrator would require having the appropriate connectors.

A protocol (proprietary or non-proprietary) may be required to remotely send the relayed signal over a wired media type (coaxial, fiber, ethernet, etc.), particularly so as not to limit Wi-Fi performance (perhaps for 802.11ax next generation 2.5G bidirectional ethernet). Protocols from the mobile domain, such as the CPRI (common public radio interface) protocol linking the baseband unit (BBU) of the mobile base station and the Remote Radio Head (RRH), or the IEEE P1904.3 protocol for sending radio signals over ethernet, can be easily used or adapted.

It should also be noted that the signals of the access points, and thus in particular all the transmitted SSIDs, are relayed identically. To avoid this, filtering of the desired SSID can be added at the Wi-Fi chipset of the access point.

As with conventional Wi-Fi extenders, the rules for locating remote radio modules must be followed to avoid disturbing the main access point, especially if the initial coverage of the access point is satisfactory.

When there are several Wi-Fi access points operating with different technologies, or if one access point is capable of operating according to different Wi-Fi technologies (Wi-Fi 2.4GHz, Wi-Fi 5GHz, Wi-Fi 60GHz) or 3GPP (4G, 5G....) it is advantageous to add a remote radio module (and therefore also a corresponding expansion device) for each technology (Wi-Fi 2.4GHz, Wi-Fi 5GHz, Wi-Fi 60GHz, 4G, 5G....) for which the coverage should be extended. In practice, the electronic components and the antenna are not necessarily the same, depending on the technology and the frequency band.