WO2010121993A1

WO2010121993A1 - Method for reducing the electricity consumption of a hardwired link between terminals

Info

Publication number: WO2010121993A1
Application number: PCT/EP2010/055134
Authority: WO
Inventors: Nicolas Dangy-Caye
Original assignee: Sagem Communications Sas
Priority date: 2009-04-22
Filing date: 2010-04-19
Publication date: 2010-10-28
Also published as: FR2944890A1

Abstract

The present invention relates to a method for reducing the electricity consumption of a hardwired link between remote terminals (A, B, C), each hardwired link being made via two network adapters (N1, N2, N3) communicating with one another by exchanging signals over a first type of interface (DC), each adapter (N1, N2, N3) communicating with a terminal (A, B, C) by exchanging signals over a second type of interface (ETH), the first and second types of interface of each adapter communicating with one another via the MAC layers thereof. The method is characterised in that a network adapter (N1, N2, N3) switches to a low-consumption mode (DC_HIBERNATE, ETH_HIBERNATE, DC_L1_LISTENING, ETH_L1_LISTENING, DC_SLEEP) when no activity is detected simultaneously on the MAC layer of the first type of interface (DC) thereof and on the MAC layer of the second type of interface (ETH) thereof for a predetermined period (TSLEEP) starting after the last detection of activity on the MAC layer of either one of the interfaces of said network adapter. The present invention also relates to a network adapter used by a hardwired link between two terminals.

Description

Method for reducing the wired connection power consumption between terminals

The present invention relates to a method of reducing the power consumption of wired connection between remote terminals.

It is known to connect two terminals by a cable for these terminals to exchange between them bearers of useful data type multimedia. For example, in a home installation, one of these terminals may be a residential gateway and the other terminal a Set Top Box or a computer. The gateway and the set top box are then interconnected by a first cable connection and the gateway and the computer are interconnected by a second cable connection.

Fig. 1 represents an example of a cable connection in the sense of the present invention.

In general, a wired link is subsequently defined as a means of communication between two terminals through a network of a first type and a network of a second type. The data carried by the network of the first type is transported transparently by the network of the second type and reciprocally. This transparent passage between the two networks is realized by a network adapter. These adapters share the same transport medium on the network of the first type (common wiring).

The network of the first type is, in a non-limiting manner, a CPL (Online Carrier Current) type network as defined, for example, by Homeplug (1.0 Turbo, AV) or other standards or technologies. The network of the first type can also be a network of h.pna type (G. 9954) or more generally g.hn (G.9960 being finalized).

The network of the second type is, in a non-limiting manner, an Ethernet type network, or a network provided for high speed data transmission such as audio-visual streams or a g.hn type network.

A wired connection between two terminals is subsequently defined as connecting each of the two terminals with a network adapter via the network of the second type, the two network adapters being connected via the network of the first type. According to the example of FIG. 1, two cable links are shown for connecting three terminals A, B and C. The first wired link is defined between the terminals A and B as follows. The terminal A is connected to a network adapter N1 which is connected to a network adapter N2, itself connected to the terminal B.

The second cable link is defined between terminals A and C as follows. The terminal A is connected to the network adapter N1 which is connected to a network adapter N3, itself connected to the terminal C.

Thus, the data-carrying signals which are transmitted by the terminal A via the network of the second type, are transformed in a transparent manner for the data transmitted by the network adapter N1, the transformed signals are then conveyed via the network of the first type up to 'to N2 and N3 network adapters. If the data is intended for the terminal B, the network adapter N2 transforms them transparently for the data and the transformed signals are finally routed to the terminal B via the network of the second type. It is easy to deduce from this signal exchange example how the terminals can bi-directionally exchange signals via one or the other of the cable links.

Fig. 2 schematically represents the internal structure of a network adapter N1, N2, N3 within the meaning of the present invention.

The network adapter comprises an interface (network) of the first type DC, a (network) interface of the second type ETH, an ETH connector C provided for connect the network adapter to the network of the second type ETH and another DC C connector provided to connect the network adapter to the network of the first DC type. These connectors ETH C and DC C may include, optionally, means for transforming the signals they receive into other signals that they transmit and bidirectionally.

The ETH interface groups together a set of functionalities that are implemented at two layers: an ETH PHY physical layer and a MAC (Medium Access Control) layer. These functionalities of the physical layer and MAC are implemented by hardware means which are usually presented for the physical layer in the form of a set of electronic components and for the MAC layer in the form of a processor.

The DC interface brings together a set of functionalities that are implemented at two layers: a DC PHY physical layer and a MAC (Medium Access Control) layer. These functionalities of the physical layer and MAC are implemented by hardware means which are usually presented for the physical layer in the form of a set of electronic components and for the MAC layer in the form of a processor.

The DC and ETH interfaces communicate with each other at their MAC layer as shown in FIG. 2 by the dashed vertical line. Next, activation and deactivation of an interface of a network adapter will be discussed whether it is of the first or the second type. The interface will be said to be activated when the physical resources of its physical layer and its MAC layer are electrically powered. The interface will then be able to exchange signal frames with a remote interface of the same type. The interface will be said to be deactivated when the hardware means of its physical layer will not be electrically powered. The interface then operates in a low power mode.

We will also talk about activity on the physical layer of an interface, whatever its type, to express that signals are received or emitted by the physical layer of this interface (activity on the physical layer of the interface). 'interface). The detection of an activity on the physical layer of an interface does not require that this interface is activated.

We will also talk about activity on the MAC layer of an interface, whatever its type, to express that signals are received or emitted by the MAC layer of this interface (activity on the MAC layer of the interface). The detection of an activity on the MAC layer of an interface requires that this interface is activated.

The power supply of the hardware means of the physical layer and the MAC layer of an interface of the first or second type induces an electrical consumption which, although essential when the interface is capable of exchanging signals carrying useful data, may be reduced when the host device, a terminal or network adapter, is not powered on or the link between the interface and another remote interface of the same type is not used.

Most current equipment, terminals or network adapters host an Ethernet type interface and implement a so-called Energy Detect feature. This feature can reduce the power consumption of an Ethernet interface by switching it from an active mode, that is to say a mode in which the interface is activated, to a low power mode, said listening in which the interface is disabled. Means that consume little electrical energy are then implemented to detect an activity on the physical layer of the interface in order to switch the interface to the active mode as soon as an activity on its physical layer is detected. Patent applications US6993667 and US7278039 describe the implementation of such a feature whose operation is summarized in connection with FIG. 3. The Ethernet interface operates in three modes: power off called OFF, active called ETH ACTIVE or listening called ETH L1 LISTENING.

In the OFF mode, the interface is de-energized and therefore does not consume any electrical energy. This mode corresponds, in particular, when the equipment (terminal or network adapter) is de-energized. When the equipment hosting the interface is powered up, PU event, the interface switches to ACTIVE ETH mode in which the interface is enabled. The interface then attempts to establish an Ethernet link with another remote Ethernet interface hosted by another device (terminal or adapter) during a negotiation phase between remote Ethernet interfaces. Such a phase complies with the 802.3 clause 28. Once the Ethernet link is established, the interfaces are then configured for possible exchanges of signal frames between the two devices. When an inactivity on the physical layer of the Ethernet interface is detected for a predetermined duration TL 1 IN ACTI VE (event ENL1), the interface switches from the ETH_ ACTIVE mode to the ETH L1 LISTENING mode in which the Ethernet interface is disabled. Ethernet interface switches from ETH mode to LISTENING mode

ETH ACTIVE, when an activity on its physical layer has been detected (ELl event) or when an activation command (PU event) has been sent from, for example a button of the equipment that hosts the interface. An Ethernet link is then established between remote interfaces and signal exchanges between equipment can begin as explained above.

The Ethernet interface switches from ETH ACTIVE mode or ETH L1 LISTENING mode to OFF mode when the host device is powered off.

An Ethernet interface hosted by a device implementing the energy detection functionality described in connection with FIG. 3 thus saves electrical energy when inactivity on the physical layer of the Ethernet interface is detected for a predetermined time and activate this interface as soon as an activity of its physical layer is detected or that an activation command emanates from the host equipment. However, the implementation of the energy detection function by a network adapter of a wired link as defined above, does not optimize the power consumption of the link because only the Ethernet interface (interface the second type) of each network adapter is put into a low power mode as shown in FIG. 4. Let's take the example of FIG. 1 and consider that the network of the first type is a CPL network. Suppose, still as an illustration, that the terminal A consumes 7 watts, the terminal B 10 watts and the terminal C 80 W when their interface of the second type ETH (Ethernet) is activated, and that each network adapter consumes 4 watts when their interfaces of the second type ETH (Ethernet) and the first type DC are activated. Bold lines mean that interfaces are enabled and their links to each other established.

Suppose now that terminal B is powered down. The Ethernet ETH interface of this terminal as well as that of the network adapter N2 are then deactivated (represented by thin lines in Fig. 4b). The consumption of terminal B is only 1 watt and that of the N2 network adapter 3 watts. The Ethernet link between the Ethernet interfaces of the terminal B and the network adapter N2 is broken and this part of the cable connection between the terminals A and B is in a low power mode. It may be noted that this is not the case for the first DC type interface of the network adapter N2 which remains activated (bold line on the left part of the square representing this network adapter).

The problem solved by the present invention is furthermore to optimize the reduction of the power consumption of each network adapter over the entire cable link or at least to ensure that the parts of this link which are not used are find in a low consumption mode.

To this end, the invention relates to a method for reducing the wired connection power consumption defined above which is characterized in that a network adapter switches to a low power mode when inactivity on the MAC layer of its interface of the first type and inactivity on the MAC layer of its second type interface are jointly detected for a predetermined time starting from the last activity detection on the MAC layer of one of the two interfaces of this network adapter.

Thus, the present invention generally consists in detecting the activity on the MAC layer of the interfaces of the first and second type of a network adapter of the link. The detection of inactivity on the MAC layer of the second type interface for a predetermined duration indicates that no useful data is exchanged between the terminal and the network adapter to which it is connected, and the detection of a inactivity on the MAC layer of the first type interface during this time indicates that no useful data is exchanged between the network adapter and another network adapter to which it is attached.

Thus, step by step, each network adapter of the wired link is put into a low power mode and the interface of the first and second type of each network adapter can be activated by detecting an activity on the physical layer of the network. interface of the first type, or the interface of the second type as will be seen in more detail later.

According to its material aspects, the present invention relates to a network adapter that implements such a method.

The characteristics of the invention mentioned above, as well as others, will appear more clearly on reading the following description of an example of embodiment, said description being made in connection with the accompanying drawings, among which:

Fig. 1 represents an example of a wired connection in the sense of the present invention, FIG. 2 schematically represents the internal structure of a network adapter within the meaning of the present invention,

Fig. 3 shows a state diagram relating to the operation of an Ethernet interface of the state of the art which implements the energy detection functionality, FIG. 4 represents a diagram illustrating the switchover of a network adapter into a low-power mode according to the state of the art,

Fig. 5 shows a state diagram of the method for reducing the wired connection power consumption according to the present invention,

Fig. 6 represents an example of optimization of the power consumption of a cable link according to the first embodiment of the method when a terminal goes to sleep,

Fig. 7 represents an example of optimization of the electrical consumption of a cable link according to the first embodiment of the method when a terminal leaves a standby mode, FIG. 8 represents an example of optimization of the power consumption of a cable link according to the first embodiment of the method when a network adapter is connected to more than two terminals and one goes on standby,

Fig. 9 shows an example of a timing diagram of the states in which a network adapter operates as well as the relationship between the durations used by the method with respect to the duration of the active modes and the low consumption of the method,

Fig. 10 represents an example of optimization of the power consumption of a cable link according to the first embodiment of the method when a network adapter is connected to more than two terminals, one being in standby and the other going on standby Fig. 11 shows a state diagram of this second embodiment of the wired connection power consumption reduction method according to the present invention, Fig. 12 is a block diagram of an embodiment of a network adapter which implements one of the methods according to the present invention described in connection with FIGS. 5, and

Fig. 13 is a block diagram of an embodiment of a network adapter which implements one of the methods according to the present invention described in connection with FIGS. 11.

The present invention relates to a method for reducing the wired connection power consumption between remote terminals, in this case between the terminals A, B and between the terminals A, C according to the two wired links of the illustrative example of FIG. 1.

Each cable connection is made through two network adapters, in this case N1, N2 and N1, N3. The network adapters communicate with each other by exchanging signals at interfaces of the first type DC and each network adapter communicates with a terminal by exchanging signals at their interfaces of the second type ETH. The interfaces of the first and second types of each network adapter communicate with each other through their MAC layers as illustrated in FIG. 2.

According to a characteristic of the process, any eventual bi-directional activity

(Transmitting or receiving a signal) on the MAC layer of the second ETH type interface of each network adapter is detected. The same is true of any activity on the MAC layer of the first type DC interface of each network adapter. When an inactivity on the MAC layer of the interface of the first type and an inactivity on the MAC layer of the interface of the second type of the same network adapter are jointly detected for a predetermined duration TSLEEP, the interfaces of the first and second type of this network adapter are disabled.

The network adapter then switches to a low power mode. Thus, step by step, when the interface of the second type of a network adapter switches to a low power mode, the network adapter that is connected to this terminal also switches to a low power mode. This results in an optimization of the reduction of the power consumption of the different network adapters of a cable connection between two terminals.

The references of FIGS. which are common designate the same elements. Fig. 5 shows a state diagram of a first embodiment of the wired connection power consumption reduction method according to the present invention.

When a network adapter Ni (i = 1, 2, 3 according to the example of Fig. 1) is not electrically powered, the interface of the first type DC and the interface of the second type ETH are de-energized and do not consume any electrical energy. These interfaces operate in the OFF mode.

When the network adapter Ni is powered up (PU event), the interface of the first type DC switches into a DC ACTIVE active mode. The DC interface then tries to establish a link with another interface of the first remote type hosted by another network adapter. Once the link is established, the interfaces of the first type are then configured for possible signal exchanges between the two adapters.

When the network adapter Ni is powered up (PU event), the interface of the second type ETH switches to a mode called active ETH ACTI VE. The ETH interface then tries to establish a link with another interface of the second remote type hosted by a terminal. Once the link is established, the interfaces of the second type are then configured for possible signal exchanges between the network adapter and the terminal. The interface of the first type DC of a network adapter Ni operates either in the OFF mode, or in the DC ACTIVE mode in which the physical layer and the MAC layer of the interface are activated, or in a DC L1 LISTENING mode says Level 1 listener in which the physical layer of the interface is deactivated, either in a LISTENING mode DC L2 said level 2 listening in which the physical layer and the MAC layer of the interface are activated and the interface of the first type DC of this network adapter attempts to establish a link with another interface of the first type remote DC for a predetermined duration TSync called synchronization, either in a DC transient mode HIBERNATE in which the physical layer of the interface is disabled. The interface of the second type ETH of a network adapter Ni operates either in an ACTIVE active ETH mode in which the physical layer and the MAC layer of the interface are activated, or in a mode ETH L1 LISTENING said of listening of level 1 in which the physical layer of the interface is disabled, either in a ETH HIBERNATE transient mode in which the physical layer of the interface is disabled.

When an inactivity on the MAC layer of the first DC type interface of a network adapter Ni and an inactivity on the MAC layer of the second type ETH interface of the same network adapter Ni are jointly detected for the predetermined duration TSLEEP starting from the last detection of activity on the MAC layer of one of these two interfaces (event NL2), the interface of the second type ETH switches from the ETH ACTIVE mode to the ETH HIBERNATE mode, and the interface of the first DC type switches from DC ACTIVE mode to DC HIBERNATE mode.

The interface of the second type ETH of a network adapter Ni switches from the active mode ETH ACTIVE to the level 1 listening mode ETH L1 LISTENING when an inactivity on the physical layer of the interface of the second type ETH of this adapter network Ni is detected for a predetermined time T LI INACTIVE starting from the last activity on this physical layer (event ENL1).

The interface of the second ETH type of a network adapter Ni switches from the ETH HIBERNATE transient mode to the ETH L1 LISTENING level 1 listening mode when an ELC condition is verified.

According to one embodiment, the ELC condition is verified when an inactivity on the physical layer of the interface of the second type ETH of this network adapter Ni is detected for a predetermined duration TL 1 INACTIVE starting from the last activity on this physical layer.

According to another embodiment, which can be combined with the previous one, the ELC condition is verified at the expiry of a predetermined duration ETH OFF starting from the input of the interface of the second type ETH of this network adapter in the transient mode.

The interface of the second type (ETH) of a network adapter Ni switches from the level 1 listening mode ETH_L1 LISTENING to the active mode ETH ACTIVATE ATE when an activity is detected either on the physical layer of the interface of the second ETH type of this network adapter is on the MAC layer of the first type DC interface of this network adapter (event EL1DL2).

The interface of the second type ETH of a network adapter Ni switches from the transient mode ETH HIBERNATE to the active mode ETH_ ACTIV ATE when a activity is detected on the MAC layer of the first DC type interface of this network adapter (DL2 event).

The interface of the first DC type of a network adapter Ni switches from the DC HIBERNATE transient mode to the active DC ACTIVE mode when activity is detected on the MAC layer of the second ETH type interface of this network adapter (EL2 event ).

The first type DC interface of a network adapter Ni switches from transient mode DC HIBERNATE to level 1 listening mode

DC L1 LISTENING following a predetermined duration DC TOFF starting from the input of the interface of the first type DC of this network adapter in the transient mode (DLC event).

The interface of the first type DC of a network adapter Ni switches from listening mode of level 1 DC Ll LISTENING to the active mode DC ACTIV ATE when an activity is detected on the MAC layer of the interface of the second type ETH of this adapter (event EL2).

The first DC type interface of a network adapter Ni switches from DC L1 LISTENING level 1 listening mode to level 2 listening mode

DC L2 LISTENING when an activity is detected on the physical layer of the first DC type interface of this network adapter (DLl event). The interface of the first DC type of a network adapter Ni switches from the DC L2 LISTENING level 2 listening mode to the DC ACTIVE active mode when an activity is detected on the MAC layer of the first type interface

DC of this network adapter is on the MAC layer of the second type interface

ETH of this network adapter (event L2). The interface of the first type DC of a network adapter Ni switches from listening mode of level 2 DC L2 LISTENING to the transient mode

DC HIBERNATE when an SC condition is verified.

According to one embodiment, the condition SC is verified when an inactivity on the MAC layer of the interface of the first type DC of this network adapter and an inactivity on the MAC layer of the interface of the second type ETH of this network adapter. are detected together for a predetermined duration TON starting from the last activity detection on the MAC layer of one of the two interfaces of this network adapter. According to another embodiment, which can be combined with the previous one, the condition SC is verified when an inactivity on the physical layer of the interface of the first type DC of this network adapter is detected for a predetermined duration DC LI INACTIVE starting at from the last activity on the physical layer of the interface of the first DC type.

According to one embodiment, the duration DC TOFF is greater than the sum of the durations TON and TSync.

Fig. 6 shows an example of optimization of the power consumption of a cable link according to the first embodiment of the method when a terminal goes to sleep.

Consider a wired connection between terminals A and B whose interfaces of the second typical ETH are activated (bold lines in Fig. 6a). The interfaces of the first DC and second ETH type network adapters Nl and N2 operate in an active mode (DC ACTIVE, ETH ACTIVE). Suppose that Terminal B informs Terminal A that it will go to sleep.

The terminal A then stops sending signals to the terminal B. The standby of the terminal B causes the stop of its ETH interface thus causing the event ENL1. The interface of the second type ETH of the network adapter N2 is then deactivated (ETH L1 LISTENING). The link between the interface of the second type ETH and that of the network adapter N2 is no longer established (fine lines in Fig. 6b). Terminal B consumes only IW and the 3W network adapter.

Consider now that a TSLEEP duration has elapsed since the stop of the signals transiting between the terminals A and B causing the event NL2.

The interface of the first DC and the second ETH type of the network adapter Nl and the interface of the first type DC of the adapter N2 are deactivated

(DC HIBERNATE, ETH HIBERNATE).

The network adapters N1 and N2 then operate in a low power mode (IW for each adapter and 6W for the terminal A whose interface of the second type has been disabled) (thin lines in Fig. 6c). When the DC OFF time expires, the interface of the first type DC of the network adapters N1 and N2 switches from the DC HIBERNATE mode to the DC LISTENING mode (DLC event). At the end of the ETH OFF duration or in the absence of level 1 activity during T L1 INACTIVE (ELC event), the interface of the second ETH type of the network adapter N1 switches from the ETH HIBERNATE mode to the ETH L1 LISTENING mode.

Fig. 7 shows an example of optimization of the power consumption of a cable link according to the first embodiment of the method when a terminal leaves a standby mode.

Fig. 7a resumes the scenario of FIG. 6c in which the network adapters N1 and N2 operate in a low power mode (ETH LI LI STENING and DC LISTENING L).

Now let's say Terminal B is coming out of standby mode. Its interface of the second type ETH is activated causing the event EL 1DL2. The interface of the second ETH type of network adapter N2 is enabled (switches to ETH ACTIVE mode). The network adapter N2 exits its low power mode (bolded in Fig. 7b). The terminal B consumes 1OW and the network adapter N2 2W because its first DC type interface remains disabled. Terminal B transmits signals that cause event L2 to switch the interfaces from the first DC and network adapter N2 to an active mode (DC ACTIVE) (Fig. 7c).

The event DL1 switches the interface of the first type DC of the network adapter N1 to the active mode DC L2 LISTENING causing the activation of the first type interface DC of this network adapter (3W) and makes it possible to receive the L2 event causing the switchover of the first type interfaces and the second type to an active mode (DC ACTIVE, ETH ACTIVE). (Fig. 7d and e).

Fig. 8 shows an example of optimization of the power consumption of a cable link according to the first embodiment of the method when a network adapter is connected to more than two terminals and one goes to sleep. According to this example, two cable links use the network adapter N1. Let us consider the terminals A, B and C whose interfaces of the second type ETH are activated (bold lines in Fig. 8a). The link between interfaces of the first DC and the second ETH type network adapters Nl, N2 and N3 operate in an active mode (DC ACTIVE, ETH ACTIVE).

Suppose that Terminal B informs Terminal A that it will go to sleep. The terminal A then stops sending signals to the terminal B. The standby of the terminal B causes the stopping of its interface of the second type thus causing the ENLl event. The interface of the second type ETH of the network adapter N2 is then deactivated (ETH L1 LISTENING). The link between the interface of the second type ETH and that of the network adapter N2 is no longer established (thin lines in Fig. 8b). Terminal B only consumes IW and network adapter N2 3 W. In the case where signals are exchanged between terminals A and C, activity is detected on the MAC layer of adapters N1 and N3 maintaining an active state of their first and second type interfaces (ETH ACTIVE, DC ACTIVE).

Consider now that a TSLEEP duration has elapsed since the stop of the signals transiting between the terminals A to B causing the event NL2 and the deactivation of the first type interface DC of the adapter N2 (DC HIBERNATE).

At the end of the duration DC TOFF which starts from the input of the interface of the first type DC of the network adapter N2 in the transient mode (DLC event), the interface of the first type DC of the N2 network adapter switches to DC L 1 LISTENING mode.

When the terminals A and C exchange signals with each other via the network adapter N1 and N3, an activity is detected on the physical layer of the interface of the first type DC of the network adapter N2 (event DL1). The interface of the first DC type of the network adapter N2 then switches from the level 1 listening mode DC LISTENING DC to level 2 listening DC L2 LISTENING mode.

In the case where the terminal A transmits a signal to the terminal B, an activity is detected on the MAC layer of the first type DC interface of the network adapter N2 (event L2). The interface of the first type DC of the network adapter N2 then switches from listen mode level 2 DC L2 LISTENING to the active mode DC ACTIVE, and the interface of the second type ETH from the network adapter N2 of the mode D listening level 1 ETH_ L1 LISTENING to active mode ETH ACTIV ATE (event EL1DL2). The network adapter N2 is then released from its low power mode.

When the first DC type interface of the N2 network adapter is in DC L2 LISTENING level 2 listening mode and an inactivity on the MAC layer of the first DC type interface of the network adapter N2 and inactivity on the MAC layer of the second ETH type interface of this network adapter are jointly detected for the predetermined duration TON starting from the last activity detection on the MAC layer of one of the two With the interfaces of this network adapter (SC condition checked), the first DC type interface of an N2 network adapter switches from DC L2 LISTENING level 2 listening mode to the DC HIBERNATE transient mode.

Thus, the interface of the first DC type of the network adapter N2 switches from the transient mode to DCL1 LISTENING level 1 listening mode and then to the DC L2 LISTENING level 2 listening mode and then to the transient mode.

DC HIBERNATE and as long as there are no signals exchanged between the terminals

A and B.

Fig. 8c illustrates this operation. The interface of the first DC and the second ETH type network adapters Nl and N3 remains enabled as the terminals A and C continue to exchange signals and the N2 network adapter operates in a low power mode (IW) without disturbing the exchange of signals between the terminals A and C and still remaining attentive to any signals relating to the terminal B. FIG. 9 shows an example of a timing diagram of the states in which a network adapter operates as well as the relationship between the duration DC TOFF, TON and DC TOFF with respect to the duration of the active and listening modes of the method.

The duration DC TOFF is equal to the sum of the durations passed by the interface of the first DC type in a low power mode (DC HIBERNATE and DC_L1_LISTENING). The duration T, equal to the sum of the durations TSYNC and TON, is the duration spent by this interface in an active mode (DC L2 LISTENING).

Fig. 10 represents an example of optimization of the power consumption of a cable link according to the first embodiment of the method when a network adapter is connected to more than two terminals, one being in standby and the other going on standby .

By repeating the scenario described in connection with FIG. 8c, the interface of the second type ETH of the network adapter N2 is deactivated and the interface of the first type DC of this network adapter switches between DC HIBERNATE modes,

DC LISTENING and DC L2 LISTENING as long as terminals A and C exchange signals (Fig. 10a).

Suppose that the terminal C informs the terminal A that it will go to sleep. The terminal A then stops sending signals to the terminal C. The interface of the second type ETH of the network adapter N3 is deactivated (ETH L1 LISTENING). The link between the interface of the second type ETH and that of the network adapter N3 is no longer established (fine lines in Fig. 10b). Terminal C only consumes IW and the N3 3W network adapter.

Consider now that a TSLEEP time has elapsed since the input of the Nl, N2 and N3 network adapter interfaces in the ETH_ACTIVE and DC ACTI VE mode causing the NL2 event. The interface of the first DC type of the N3 adapter is deactivated (DC HIBERNATE) and the link between the first DC type interfaces of the network adapters N1 and N3 is no longer established and as explained above, the network adapters N1 and N3 operate in a low power mode (fine lines in Fig. 8c). When one of the terminals B or C goes out of its standby mode, the network adapters go out of their low consumption mode as explained above.

The inventor has observed that the time required for failover of all wired network adapters in a low power mode increases as the number of network adapters used by more than one wired link increases.

In addition, the inventor has also observed that once a network adapter is in its low power mode, this network adapter could unexpectedly exit this mode by the activity of a neighboring network that interferes with the network. of the first type. This is particularly troublesome when the medium where the network of the first type is deployed has a high network density.

To overcome these disadvantages, according to a second embodiment of the method, a network adapter Ni leaves a low power mode (DC SLEEP) once received a specific message MSGj in acknowledgment of a message MSGi issued by this network adapter Ni . The two network adapters Ni and Nj form a single network adapter pair to which the specific messages MSGi and MSGj are associated.

In practice, the acknowledgment of the message MSGj is achieved by sending a message MSGi from the network adapter Ni to the network adapter Nj. The content of the messages MSGi and MSGj is then unique and specific to the pair of network adapters (Ni ₅ Nj).

Thus, according to this embodiment, a network adapter Ni of a pair of adapters (Ni, Nj) can not come out of its low power mode until it has received the message MSGj which acknowledges the reception, for example. the network adapter Nj of the message MSGi previously sent by the network adapter Ni. In other words, the interfaces of the first DC and second ETH type of an adapter of a pair can no longer switch unexpectedly from a listening mode to the active mode due to interference from a neighboring network.

Fig. 11 shows a state diagram of this second embodiment of the wired connection power consumption reduction method according to the present invention.

The operation of the interface of the second type ETH of a network adapter remains unchanged with respect to the first embodiment of the method described in connection with FIG. 5. The interface of the first type DC of a network adapter Ni of a pair of adapters (Ni ₅ Nj) operates in six modes: DC ACTIVE, DC SLEEP, SEND HELLO, HELLO LISTENING, HELLO AGAIN and REPLY HELLO.

The first DC type interface is disabled in the last five modes while it is enabled in the DC ACTIVE mode. These five modes are distinguished by their input and output conditions in these modes.

When the network adapter Ni is powered up, PU event, the interface of the first DC type of this network adapter, denoted DCi, switches to the mode

SEND HELLO in which the interface DCi remains deactivated and a message MSGi is sent to the interface of the first type DC of the other network adapter Nj of the pair (Ni ₅ Nj), denoted DCj.

Once the message MSGi has been sent, the interface DCi switches to the mode

HELLO LISTENING in which the interface DCi is waiting, for a predetermined duration T HELLO, for receiving a message MSGj sent by the interface DCj following its reception of the message MSGi by the interface DCj (acknowledgment of the sending the message MSGi by the network adapter Nj).

In the case where the message MSGj is not received during the duration T HELLO (event NH), the interface DCi switches to SEND mode HELLO.

In the event that the message MSGj is received before the expiration of the duration T HELLO (event H), the interface DCi switches to the HELLO AGAIN mode in which a new message MSGi is sent. It can be noted that the duration T HELLO is specific to each network adapter of a pair (Ni, Nj).

Once the MSGi message has been sent by the DCi interface, the DCi interface switches to the DC ACTIVE mode. The DC interface then tries to establish a link with another interface of the first remote type hosted by another network adapter. Once the link is established, the interfaces of the first type are then configured for possible signal exchanges between the two adapters.

The interface of the first DC type of a network adapter switches from DC ACTIVE mode to DC SLEEP mode when an inactivity on the MAC layer of the first DC type interface of this network adapter and an inactivity on the MAC layer of the interface of the second ETH type of this network adapter is jointly detected for the predetermined duration TSLEEP starting from the last activity detection on the MAC layer of one of the two interfaces of this network adapter (event NL2). The interface of the first type DCi of a network adapter Ni switches mode

DC SLEEP to SEND HELLO mode during activity detection on the MAC layer of the second type ETHi interface (EL2 event).

The interface of the first type DCi of a network adapter Ni switches mode

DC SLEEP to the REPLY HELLO mode when a message MSGj, sent by the network adapter Nj, has been received (event AR) and in turn transmits an acknowledgment message MSGi. The eventual activity of the physical layer of the interface of the first type DCi is then detected.

The interface of the first type DCi of a network adapter switches from

REPLY HELLO to DC SLEEP mode when inactivity on its physical layer is detected for a second predetermined time T LI INACTIVE starting from the last activity on the physical layer of the first DC type interface of the network adapter ( event DNLl).

The interface of the first type DCi switches from the REPLY HELLO to the DC ACTIVE mode when an activity is detected on the physical layer of the interface of the first type DCi (event DL1).

According to a variant of this embodiment, the interface of the first DC type of a device switches from the REPLY HELLO mode to the DC ACTIVE mode following the transmission of the acknowledgment message MSGi.

Fig. 12 is a block diagram of an embodiment of a network adapter which implements one of the methods according to the present invention described in connection with FIGS. 5.

The network adapter Ni comprises hardware means for implementing the functionalities of the physical layer and the MAC layer of an interface of a first type DC and an interface of a second type ETH. The hardware means implementing the functionalities of the physical layer of the interface of the second type ETH are here represented by a set of electronic components ETH PHY.

The hardware means implementing the functionalities of the physical layer of the first DC type interface and the MAC layers of the first and second type interface are here represented by a set of MAC / DC PHY electronic components.

The network adapter Ni also comprises an ETH connector C intended for the connection of a cable, compatible with the network of the second type ETH, and an ETH detector Ll DETECT of the activity of the physical layer of the interface of the second type ETH.

The ETH PHY assembly is connected, on the one hand, to the MAC / DC PHY assembly by a bus of the Mil type and, on the other hand, to the ETH C connector.

The ETH L1 DETECT detector is based on discrete components whose input is connected on the link between the ETH C connector and the ETH PHY set in the Rx signal reception direction. The output AL1 can be wired on an interrupt line of a microprocessor. Thus, when a signal is received by the ETH connector C, the output AL1 changes state thereby signifying an activity on the physical layer of the interface of the second type ETH. The network adapter Ni also includes a DC C connector provided for the connection of a cable compatible with the network of the first type DC and a DC detector L1 DETECT of the activity of the physical layer of the interface of the first type DC.

The MAC / DC PHY assembly and the DC C connector are interconnected. Thus, when a signal is received by the ETH connector C, it is transmitted to the set ETH PHY in the direction Rx. This signal is then transmitted to the ETH PHY set which transmits it to the MAC / DC PHY set via bus B in the Rx direction. The signal is then transformed by the MAC / DC PHY set transparently for data routed to another signal compatible with the network of the first type. The transformed signal is then transmitted to the DC connector C. Conversely, when a signal is received by the DC connector C, it is transmitted to the MAC / DC PHY set. The signal is then transformed by the MAC / DC PHY set transparently for data routed to another signal compatible with the network of the second type. The signal is then transmitted to the ETH PHY set via the bus B in the Tx signal transmission direction. This signal is then transmitted in the Tx direction to the ETH connector C.

When the network of the first type is a carrier current network (CPL), the DC detector L1 DETECT is an OFDM symbol detector. When the second type network is an Ethernet network, the detector

ETH Ll DETECT relies on an NLP / FLP pulse detector according to the 802.3 clause 28.

The network adapter Ni also comprises a processor P which implements the method according to the present invention. For this purpose, the processor P comprises means TM for implementing duration counters (TSLEEP, T LI INACTIVE,

ETH TOFF, TOFF DC, TON, DC LI INACTIVE, TSYNC (for mode 2 TSLEEP,

T LI INACTIVE, ETH TOFF, TON T HELLO TSLEEP).

The processor P also comprises DC L2 ACTIVITY means for detecting the activity of the MAC layer of the interface of the second type ETH. For this, the processor is connected to the bus B in the direction of receiving Rx signals that is to say to detect the signals that pass on the bus B of the set ETH PH Y to the MAC / DC PHY set .

The processor P also comprises ETH L2 ACTIVITY means for detecting the activity of the MAC layer of the interface of the first type ETH. For this, the processor is connected to the bus B in the signal transmission direction Tx, that is to say to detect the signals that transit on the bus B of the MAC / DC PHY set to the ETH PHY set.

The processor P comprises a memory and calculation means (not shown) for implementing the logic of one of the methods of FIG. 5 when communicating with them in the following ways: D C L 2 AC T I V I T Y, ETH L2 ACTIVITY, TM, ETH L DETECT and DC LL DETECT.

For this purpose, the processor is connected to the output of the ETH detector L1 DETECT so as to receive the output AL1 and the DC detector L1 DETECT.

The processor P is also connected to the set ETH PHY, on the one hand to send it an EN ETH signal intended to either deactivate this set or to activate it according to the method of the present invention, and, on the other hand, to receive from this set an LS signal which informs the processor of the result of a negotiation phase for the establishment of a link via the second type network between remote interfaces. The processor P is also connected to the MAC / DC PHY assembly on the one hand to send it an EN DC signal intended to either deactivate this set or to activate it according to the method of the present invention, and, on the other hand , to receive from this set a signal LS which informs the processor of the result of a negotiation phase for the establishment of a link via the network of the first type between remote interfaces.

Fig. 13 is a block diagram of an embodiment of a network adapter which implements one of the methods according to the present invention described in connection with FIGS. 11. The means TM implement time counters (TSLEEP,

T LI INACTIVE, ETH TOFF, TON T HELLO TSLEEP).

The processor P also comprises means HELLO RECEIVED for detecting that a message MSGi or an acknowledgment message MSGj is received via the connector DC C, means SEND HELLO for transmitting a signal MSGi or of acknowledgment MSGj.

Claims

1) A method for reducing the wired connection power consumption between remote terminals (A, B, C), each wired connection being made through two network adapters (N1, N2, N3) communicating with each other by signal exchange at the interfaces of a first type (DC), each adapter (N1, N2, N3) communicating with a terminal (A, B, C) by exchange of signals at interfaces of a second type (ETH), the interfaces of the first and second types of each adapter communicating with each other through their MAC layers, a network adapter (N1, N2, N3) switching into a low power mode

(DC HIBERNATE, ETH HIBERNATE, DC LISTENING, DC

ETH L1 LISTENING, DC SLEEP) when an inactivity on the MAC layer of its interface of the first type (DC) and an inactivity on the MAC layer of its interface of the second type (ETH) are jointly detected for a predetermined duration (TSLEEP) starting from the last activity detection on the MAC layer of one of the two interfaces of this network adapter, characterized in that

its first type interface (DC) switches from a low power mode to a so-called active mode (DC ACTIVE) in which the physical layer and the MAC layer of this interface are activated, ie when an activity is detected on the layer MAC interface of the second type (ETH) when an activity is detected on the physical layer of its interface of the first type (DC),

its interface of the second type (ETH) switches from a low power mode to a so-called active mode (ETH ACTIVE) in which the physical layer and the MAC layer of this interface are activated when an activity is detected either on the MAC layer of its interface of the first type (DC), or on the physical layer of its interface of the second type (ETH).

2) The method of claim 1, wherein the interface of the first (DC) and the second (ETH) type of each network adapter can also work - either in a level 1 said listening mode (DC L 1 LISTENING,

ETH L1 LISTENING) in which the physical layer of each interface is deactivated, - either in a transient mode (ETH HIBERNATE, DC HIBERNATE) in which the physical layer of the interface is deactivated,

- the interface of the first (DC) and second (ETH) type of the same network adapter switching from active mode (ETH ACTIVE, DC ACTIVE) to the transient mode (ETH HIBERN ATE, DC HIBERNATE) when inactivity on the MAC layer of the interface of the first type (DC) of this network adapter and inactivity on the MAC layer of the second type interface (ETH) of this network adapter are jointly detected for the predetermined duration (TSLEEP) starting from the last activity detection on the MAC layer of one of the two interfaces of this network adapter.

3) Method according to claim 2, wherein the interface of the second type (ETH) of a network adapter switches from the active mode (ETH ACTIVE) to the level 1 listening mode (ETH L1 LISTENING) when inactivity on the physical layer of the second type interface (ETH) of this network adapter is detected for a predetermined time (T_L1_IN ACTI VE) starting from the last activity on this physical layer.

4) Method according to claim 2 or 3, wherein the interface of the second type (ETH) of a network adapter switches from the transient mode (ETH HIBERNATE) to the level 1 listening mode (ETH L1 LISTENING) when an inactivity on the physical layer of the second type interface (ETH) of this network adapter is detected for a predetermined duration (T_L1_IN ACTI VE) starting from the last activity on this physical layer.

5) Method according to one of claims 2 to 4, wherein the interface of the second type (ETH) of a network adapter switches from transient mode (ETH HIBERNATE) to level 1 listening mode (ETH L1 LISTENING ) at the expiration of a predetermined duration (ETH OFF) starting from the input of the interface of the second type (ETH) of this network adapter in the transient mode.

6) Method according to one of claims 2 to 5, wherein the interface of the second type (ETH) of a network adapter switches from listening mode level 1 (ETH_ L1 LISTENING) to the active mode (ETH ACTIVATE ) when an activity is detected either on the physical layer of the second type interface (ETH) of this network adapter, or on the MAC layer of the first type interface (DC) of this network adapter.

7) Method according to one of claims 2 to 6, wherein the interface of the second type (ETH) of a network adapter switches from transient mode (ETH HIBERNATE) to the active mode (ETH ACTIV ATE) when an activity is detected on the MAC layer of the first type (DC) interface of this network adapter.

8) Method according to one of claims 2 to 7, wherein the interface of the first type (DC) of a network adapter switches from transient mode (DC HIBERNATE) to the active mode (DC ACTIVE) when an activity is detected on the MAC layer of the second type (ETH) interface of this network adapter.

9) Method according to one of claims 2 or 8, wherein the interface of the first type (DC) of a network adapter switches from transient mode (DC HIBERNATE) to level 1 listening mode (DC L1 LISTENING ) following a predetermined duration, said first, (DC TOFF) starting from the input of the interface of the first type (DC) of this network adapter in the transient mode.

10) Method according to one of claims 2 to 9, wherein the interface of the first type (DC) of a network adapter switches from listening mode level 1 (DC L1 LISTENING) to the active mode (DC ACTIV ATE) when activity is detected on the MAC layer of the second type interface (ETH) of this network adapter.

11) Method according to one of claims 2 to 10, wherein the interface of the first type (DC) of a network adapter can also operate in a so-called level 2 listening mode (DC L2 LISTENING) in which the the physical layer and the MAC layer of this interface are activated and the interface of the first type (DC) of this network adapter attempts to establish a link with another interface of the first type (DC) remote for a predetermined duration of so-called synchronization ( TSync). 12) The method of claim 11, wherein the interface of the first type (DC) of a network adapter switches from the level 1 listening mode (DC L1 LISTENING) to the level 2 listening mode (DC L2 LISTENING) when an activity is detected on the physical layer of the interface of the first type (DC) of this network adapter.

13) A method according to claim 11 or 12, wherein the interface of the first type (DC) of a network adapter switches from the level 2 listening mode (DC L2 LISTENING) to the active mode (DC ACTIVE) when an activity is detected either on the MAC layer of the first type interface (DC) of this network adapter or on the MAC layer of the second type interface (ETH) of this network adapter.

14) Method according to one of claims 11 to 13, wherein the interface of the first type (DC) of a network adapter switches from level 2 listening mode

(DC L2 LISTENING) to the transient mode (DC HIBERNATE) when an inactivity on the MAC layer of the interface of the first type (DC) of this network adapter and an inactivity on the MAC layer of the interface of the second type ( ETH) of this network adapter are jointly detected for a predetermined duration (Ton), said second, starting from the last activity detection on the MAC layer of one of the two interfaces of this network adapter.

15) Method according to one of claims 11 to 14, wherein the interface of the first type (DC) of a network adapter (Ni) switches from listening mode level 2 (DC L2 LISTENING) to the transient mode (DC HIBERNATE) when an inactivity on the physical layer of the interface of the first type (DC) of this network adapter is detected for a predetermined duration (DC_L1_IN ACTIVE) starting from the last activity on the physical layer of the interface of the first type (DC).

16) Method according to one of claims 11 to 14, wherein the first duration (DC TOFF) is greater than the sum of the second duration (TON) and the synchronization time (TSync). 17) The method of claim 1, wherein the network adapter, said first, out of the low power mode (DC SLEEP) once a specific message, previously issued by the network adapter, was acquitted by another network adapter the two network adapters forming a single network adapter pair to which said specific message is associated.

18) Method according to one of claims 1 to 17, wherein the network of the first type is a network either carrier type in-line carrier, either h.pna type or g.hn.

19) Method according to one of claims 1 to 18, wherein the network of the second type is an Ethernet type network.

20) network adapter (Ni) intended to be connected on the one hand to a terminal and on the other hand to another network adapter (Nj), the network adapter comprising

a so-called first type interface intended to communicate via a network of a first type, with the interface of the first type of another network adapter,

a so-called second type interface designed to communicate via a network of a second type with the interface of the second type of a terminal; the interfaces of the first and second types of the network adapter communicating with each other through their MAC layers,

a detector (ETH Ll DETECT) of the activity of the physical layer of the interface of the second type (ETH),

a detector (DC Ll DETECT) of the activity of the physical layer of the interface of the first type (DC),

means TM for implementing duration counters (TSLEEP, INACTIVE T LI, ETH TOFF, DC TOFF, TON, INACTIVE DC LI, TSYNC ETH TOFF, TON T HELLO TSLEEP),

means (DC L2 ACTIVITY) for detecting the activity of the MAC layer of the interface of the second type (ETH),

means (ETH L2 ACTIVITY) for detecting the activity of the MAC layer of the interface of the first type (ETH), and characterized in that it comprises means (P) for implementing the logic of the one of the methods according to one of claims 1 to 19.