FR3168114A1 - Method for managing the operating mode of an access point, access point, communication method, and user equipment - Google Patents

Abstract

Method for managing an access point operating mode, access point, communication method, and user equipment The method for managing an access point operating mode (2-1) of a telecommunications network (NW) comprises, following a specific event related to at least one network device detected in the network: - a step of switching the access point to a degraded operating mode in which the access point operates at reduced capacity; and - a step of announcing, within a coverage area of the access point, said degraded operating mode of the access point. Figure for the abstract: Fig. 1.

Description

Method for managing the operating mode of an access point, access point, communication method, and user equipment

The invention falls within the general field of telecommunications.

It relates more specifically to the management of an operating mode of an access point of a telecommunications network, such as for example a base station of a 5G mobile network also called a gNodeB. The invention is applicable however to all types of networks and to all types of access points.

With climate change, most companies, and in particular fixed and mobile network operators, are now sensitive to issues of sustainable development and corporate social responsibility (CSR). Some companies have already set themselves targets for reducing their energy consumption and carbon footprint, and more generally for improving their energy efficiency.

In the context of mobile networks, and particularly those defined by the 3GPP standard (Third Generation Partnership Project), the search for improved energy efficiency was initially addressed at the level of user equipment (UE). The UE is indeed the most constrained entity in terms of energy budget, and improving its energy efficiency allows, in particular, for maximizing its autonomy and preserving its battery health. Thus, various mechanisms have been defined over the years by the 3GPP standard for this purpose, such as discontinuous reception (DRX), wake-up signals (WUS), adaptive monitoring of the physical downlink control channel (PDCCH), paging early indication (PEI), and so on.

More recently, energy efficiency in network equipment has become a strategic issue for mobile network operators, driven by the ever-increasing data rates offered by these networks and the network densification inherent in new generations of mobile radio systems. Beyond CSR concerns, network energy consumption represents a growing share of operators' operating expenses (OPEX).

Various approaches can be considered to control the energy consumption of network equipment, and more specifically that of network access points such as base stations.

A first approach is typically linked to spectral efficiency, and focuses on the design of L1 and L2 layers in order to achieve the best possible data rates for the lowest possible signal-to-noise plus interference ratio.

A second approach, also known as Advanced Sleep Mode (ASM), involves exploiting periods of low upstream or downstream traffic through the access point to switch it to sleep mode. This second approach was initially implemented proprietaryly by infrastructure vendors, and subsequently by operators. Later, standardized elements were gradually introduced at the 3GPP level under the name "Network Energy Saving techniques."

These network energy-saving techniques specifically target adaptations to the operating mode of network base stations in terms of signal power, active antennas, bandwidth, and/or discontinuous transmission/reception (DRX/DTX). In other words, the base station operates in a low-energy consumption state, resulting in reduced capacity in terms of resources (transmitted power, active antennas, spectrum, active time slots, etc.), but this does not negatively impact user equipment within its coverage area due to the low traffic associated with that equipment.

In particular, a technique commonly considered in this context, and when the base station has multiple frequency bands, is the (total) deactivation of certain frequency bands. The implementation of this technique relies on maintaining a so-called coverage band to ensure service continuity, while the other bands are used for capacity. Thus, during periods of low traffic, the network operator can decide to deactivate certain capacity bands at a base station, provided that this is transparent to active users within the cell covered by that base station, and specifically that it does not impact their quality of service (QoS).

The use of these ASM techniques at the base station level is therefore limited today to periods of lower traffic associated with user equipment covered by the base station in order to allow a reduction in the network's energy consumption while preserving the quality of service offered to users.

It also requires a prediction of the traffic associated with the user equipment covered by the base station, for example using an artificial intelligence (AI) or machine learning (ML) algorithm. If this prediction is incorrect, activating such an ASM technique can lead to an unacceptable QoS situation for some base station users.

• une étape de basculement du point d’accès dans un mode de fonctionnement dit dégradé dans lequel le point d’accès fonctionne à capacité réduite ; et
• une étape d’annonce, sur une zone de couverture du point d’accès, dudit mode de fonctionnement dégradé du point d’accès.

The invention notably remedies the aforementioned drawbacks by proposing a method for managing an operating mode of an access point in a telecommunications network, this method comprising, following a specific event relating to at least one piece of network equipment detected in the network:

• a step involving switching the access point to a so-called degraded operating mode in which the access point operates at reduced capacity; and
• an announcement step, over a coverage area of the access point, of said degraded operating mode of the access point.

Correspondingly, the invention also relates to an access point to a telecommunications network comprising:

- a failover module configured to, following a specific event related to at least one network device detected in the network, switch the access point to a so-called degraded operating mode in which the access point operates at reduced capacity; and

- an announcement module configured to announce over a coverage area of the access point the degraded operating mode into which the access point is switched by the failover module.

Thus, the invention proposes that upon detection of a specific event, such as a change in the power supply to a network access point, the latter switches to a degraded operating mode in order to conserve its resources, and in the aforementioned example, its energy supply. The invention advantageously provides that an access point switching to such a degraded operating mode informs the user equipment it serves of this reduced-capacity operation (for example, by broadcasting this information over its coverage area), so that the equipment can adapt to this degraded operation of the access point. "Reduced capacity" means that the access point has a capacity lower than its nominal capacity, that is, the capacity for which it is designed under normal operating conditions, which reflects its ability to support a certain number of users and meet their traffic needs with a satisfactory quality of service (QoS). Such capacity depends on user traffic within its coverage area and their QoS requirements, taking into account the resources available to the access point, particularly in terms of power, connection to the core network (also called "backhaul link"), computing resources, usable bandwidth, etc. The capacity of an access point can thus be expressed, in a way that is inherently well-defined, in terms of computing capacity and/or speed, available power, available bandwidth, and/or available hardware (e.g., number of antennas, power amplifiers, etc.) at the access point, etc.

No limitations are attached to the entity initiating the access point's switch to a reduced-capacity operating mode (the access point itself or another network entity), nor to the context in which this switchover is decided. Activation of a degraded operating mode at the access point is linked to the occurrence of a specific network event, typically an event likely to reduce the access point's capacity, such as the access point implementing a technique to disable capacity-based frequency bands managed by the access point during a period of low traffic, as mentioned previously.

Advantageously, the invention is not limited to switching the access point to a reduced-capacity operating mode during periods of low traffic to avoid impacting the quality of service provided to the user equipment it serves. Thanks to the access point's notification system, which informs user equipment of the reduced capacity, the invention also enables such a switchover following the detection of other events, such as an anomaly affecting the operation of at least one piece of network equipment. This equipment could be the access point itself or another piece of network infrastructure equipment. Such an anomaly could, in particular, concern the access point's power supply or a connection link from the access point to a core network ("backhaul link") of the telecommunications network. For example, reduced capacity operation of the access point may be triggered following a mains power outage of the access point due to an incident or maintenance of predetermined duration, a switchover of the access point's mains power to a backup power supply (e.g. a battery), insufficient power supply (e.g. a battery powered by photovoltaic panels in a low sunlight context), or following a backhaul link failure, a failure of part of the network infrastructure, excessive temperature, a decrease in the available computing capacity of the access point, etc.

In another context, the mechanism proposed by the invention could be activated to adapt to the energy mix present in the access point's coverage area, and for example, reduce its electricity consumption when electricity has a significant carbon footprint, thereby enabling the network operator to meet its carbon commitments. The invention can also be used to adapt to certain regulatory constraints, particularly regarding carbon footprint, exposure to electromagnetic fields (EMF), etc. Of course, these are only illustrative examples, and the invention is applicable in many other contexts.

The invention thus enables the access point to modulate its capacity to adapt to its context (for example, by adjusting its traffic load according to its available capacity), and in particular to its energy situation or any other situation that requires it, as mentioned above, by switching to a degraded operating mode. This allows it to conserve its energy resources rather than, as in the prior art, continuing to provide services to the user equipment it serves under nominal operating conditions until its power supply is depleted. In this way, the access point can extend its autonomy, and therefore incidentally its ability to provide essential services to user equipment located within its coverage area (for example, emergency services).

Such a shift to a degraded operating mode can impact the quality of service experienced by the user devices served by the access point. Thanks to this invention, these user devices are informed of this reduced-capacity operation of the access point and encouraged to adapt to the situation (for example, by changing access points, and/or by changing their behavior and use of the access point's resources, by foregoing non-essential services, by reducing their traffic requirements, etc.), thereby limiting the risk of access point congestion. Through their behavior in response to the access point's announcement, they can also contribute to preserving the access point's resources and improving its performance while awaiting a return to full capacity.

The invention thus offers network operators great flexibility and adaptability in defining their network management policy, and in particular their energy management policy.

In a particular embodiment, the degraded operating mode into which the access point is switched is selected according to the nature and/or severity of the detected anomaly.

The invention enables the access point to autonomously trigger a degraded operating mode adapted to its situation due to the detected anomaly. It can take into account, in particular, the expected duration of the anomaly if known to the access point, its magnitude, etc., but also its nature, which may impact its capacity and how to adapt that capacity.

In particular, in a specific embodiment, the degraded operating mode into which the access point is switched may include a degradation, for at least one user device located in said coverage area of the access point, of at least one element among latency, throughput, number of allocated physical resource blocks, transmitted signal power and/or number and/or types of accessible services.

We can therefore consider gradual degraded operating modes of the access point adapted to the context and the detected event, and when this event is an anomaly affecting the operation of a network equipment, to the nature and/or severity of this anomaly.

For example, the least degraded operating modes considered by the access point may result in a decrease in the quality of service offered to users within the access point's coverage area due to the degradation of one of the aforementioned parameters (e.g., increased latency, reduced coverage area, decreased bandwidth, limitation of the number of physical resource blocks allocated to a user device, etc.). Conversely, the most degraded operating modes considered by the access point may limit the services accessible within the coverage area and, in the most extreme operating mode, allow only emergency calls and SMS (Short Message Service) messages.

• une information représentative d’un niveau de dégradation induit par le mode de fonctionnement dégradé dans lequel est basculé le point d’accès ;
• une information représentative d’au moins une zone voisine de la zone de couverture du point d’accès, couverte par au moins un autre point d’accès du réseau qui n’est pas basculé dans un mode de fonctionnement dégradé ou qui est basculé dans un mode de fonctionnement dégradé présentant un niveau de dégradation moindre ;
• une information représentative d’une durée de basculement du point d’accès dans ledit mode de fonctionnement dégradé ;
• une information représentative d’un comportement à adopter par au moins un équipement utilisateur se trouvant dans la zone de couverture du point d’accès.

In a particular embodiment, the step of announcing the management process includes at least one piece of information from:

• information representative of a level of degradation induced by the degraded operating mode into which the access point is switched;
• information representative of at least one area adjacent to the coverage area of the access point, covered by at least one other access point in the network that is not switched to a degraded operating mode or that is switched to a degraded operating mode with a lower level of degradation;
• information representative of the duration of the access point switching into said degraded operating mode;
• information representative of a behavior to be adopted by at least one user device located in the coverage area of the access point.

This information provides valuable insights to user devices, enabling them to make informed decisions regarding behavior when the access point is operating at reduced capacity. Furthermore, it informs users within the access point's coverage area about any service filtering policies the access point may be implementing based on its location. This type of information allows the access point to effectively adapt its traffic load within its coverage area according to its available capacity.

In one particular embodiment, the announcement step is implemented periodically over the coverage area of the access point.

Such periodic announcements ensure that all user equipment present or entering the coverage area of the access point is informed of the degraded operating mode of the access point.

For example, during the announcement stage, the degraded operating mode of the access point is announced in a system information block broadcast by the access point over its coverage area.

This allows a user device to have this information before connecting to the access point, and to do so, if necessary, with full knowledge of the situation, possibly adapting its behavior to the access point's energy status. Conversely, given this notification and the reduced capacity of the access point, the user device may choose not to connect to the access point and postpone its connection to the network, or select another access point that does not operate at reduced capacity.

This not only saves resources on the access point, but also limits the risk of a degraded quality of experience for network users.

The invention also applies to an announcement implemented aperiodically (for example with a period varying according to a degree of activity in the coverage area of the access point) or punctually, for example following the detection of the event leading to switching the access point to the degraded operating mode.

In view of the foregoing, the invention therefore relies not only on the management process implemented by an access point, and correspondingly, on the access point capable of implementing this process, but also on the user equipment receiving the announcement from the access point and acting accordingly.

• une étape de réception d’une annonce faite par un point d’accès sur sa zone de couverture, d’un mode de fonctionnement dit dégradé dans lequel le point d’accès fonctionne à capacité réduite et a basculé ; et
• une étape de déclenchement d’au moins une action de prise en compte du mode de fonctionnement dégradé du point d’accès.

Thus, according to a second aspect, the invention relates to a method of communication by a user device located within the coverage area of an access point of a telecommunications network, this method comprising:

• a step involving the reception of an announcement made by an access point within its coverage area, indicating a so-called degraded operating mode in which the access point operates at reduced capacity and has switched over; and
• a triggering step for at least one action to take into account the degraded operating mode of the access point.

• un module de réception configuré pour recevoir, lorsque l’équipement utilisateur se trouve dans une zone de couverture d’un point d’accès du réseau, une annonce faite par le point d’accès sur ladite zone de couverture d’un mode de fonctionnement dit dégradé dans lequel le point d’accès fonctionne à capacité réduite et a basculé ; et
• un module de déclenchement, configuré pour déclencher au moins une action de prise en compte du mode de fonctionnement dégradé du point d’accès.

Correspondingly, the invention also relates to user equipment comprising:

• a receiving module configured to receive, when the user equipment is within the coverage area of a network access point, an announcement made by the access point within said coverage area of a so-called degraded operating mode in which the access point operates at reduced capacity and has failed over; and
• a trigger module, configured to trigger at least one action to take into account the degraded operating mode of the access point.

The communication method and user equipment according to the invention benefit from the same advantages mentioned above as the management method and access point according to the invention.

No limitations are attached to actions triggered by user equipment to take into account the degraded operating mode of the access point level.

Typically, at least one action triggered during the triggering step may depend on a level of degradation likely to affect a quality of service provided to said user equipment via the access point and induced by the degraded operating mode into which the access point has switched.

For illustrative purposes, an action triggered during the triggering step may include a re-selection of another access point in the network that has not switched to a degraded operating mode or that has switched to a degraded operating mode with a lower level of degradation likely to affect a quality of service provided to said user equipment.

• une annulation et/ou une adaptation d’au moins une partie d’un trafic échangé entre l’équipement utilisateur et le point d’accès ;
• une réduction d’un nombre et/ou d’au moins un type de services accessibles par un utilisateur de l’équipement utilisateur ;
• une notification d’un utilisateur de l’équipement utilisateur.

In another example, at least one action triggered during the triggering step can be chosen from:

• a cancellation and/or adaptation of at least part of the traffic exchanged between the user equipment and the access point;
• a reduction in the number and/or at least one type of services accessible by a user of the user's equipment;
• a notification from a user of the user's equipment.

Of course, these are merely illustrative examples and are not exhaustive of the invention. Other actions can be considered to allow user equipment to adapt to the degraded operating mode of the access point. The triggered actions can be at the discretion of the user equipment, depending in particular on its environment and/or context, while taking into account the reduced capacity of the access point to avoid network congestion. Alternatively, the actions triggered in response to the access point advertisement can be imposed on the user equipment by the network operator, for example, within the access point advertisement itself.

In one particular embodiment, the management and communication processes are implemented by a computer.

The invention also relates to a computer program on a recording medium, this program being capable of being implemented in a computer or more generally in an access point according to the invention and comprising instructions adapted to the implementation of a management process as described above.

The invention also relates to a computer program on a recording medium, this program being capable of being implemented in a computer or more generally in user equipment conforming to the invention and comprising instructions adapted to the implementation of a communication process as described above.

Each of these programs can use any programming language, and be in the form of source code, object code, or code somewhere between source code and object code, such as in a partially compiled form, or in any other desirable form.

The invention also relates to an information medium or a recording medium readable by a computer, and comprising instructions for a computer program as mentioned above.

The information or recording medium can be any entity or device capable of storing programs. For example, the medium may include a storage means, such as a ROM, for example a CD-ROM or a microelectronic circuit ROM, or a magnetic recording means, for example a hard drive, or a flash memory.

On the other hand, the information or recording medium can be a transmissible medium such as an electrical or optical signal, which can be carried via an electrical or optical cable, by radio link, by wireless optical link or by other means.

The program according to the invention can in particular be downloaded onto an Internet-type network.

Alternatively, the information or recording medium may be an integrated circuit in which a program is incorporated, the circuit being adapted to execute or to be used in the execution of the management and communication processes according to the invention.

According to a third aspect, the invention also relates to a system comprising at least one access point of a telecommunications network according to the invention and at least one user device according to the invention located in a coverage area of the access point.

It can also be envisaged, in other embodiments, that the management and communication processes, the access point, the user equipment and the system according to the invention present in combination all or part of the aforementioned characteristics.

Other features and advantages of the present invention will become apparent from the description below, with reference to the accompanying drawings, which illustrate an example of an embodiment without being limiting in any way. In the figures:

FIG. 1 there FIG. 1 represents, in its environment, a system in a network conforming to the invention, in a first embodiment;

FIG. 2 there FIG. 2 schematically represents the hardware architecture of a computer capable of hosting any one of the entities according to the invention belonging to the system of the FIG. 1 ;

FIG. 3 there FIG. 3 represents, in the form of a flowchart, the main steps of a management process according to the invention as implemented by an access point of the system of the FIG. 1 ; And

FIG. 4 there FIG. 4 represents, in the form of a flowchart, the main steps of a communication process according to the invention as implemented by a user device of the system. FIG. 1 .

Description of the invention

There FIG. 1 represents, in its environment, a system 1 conforming to the invention, in a particular embodiment in which the system 1 participates in managing the operating mode of at least one access point, generally referred to as 2, of an NW telecommunications network. By way of illustration, we are interested here in an operating mode of access point 2 that allows for the control of the energy consumption of access point 2.

In the example considered in the FIG. 1 The NW network is a 5G cellular mobile network as defined by the 3GPP standard, and the access points 2 belonging to system 1 are base stations 2-1, 2-2, 2-3 of the NW network, also called gNodeBs, conforming to the invention. In a manner known per se, such a base station 2, and more generally such an access point, is configured (antennas, transmitted power, etc.) to cover a nominal geographic area, generally referenced by ZC (and more specifically by ZC-1, ZC-2, ZC-3 for base stations 2-1, 2-2, 2-3 respectively), this ZC coverage area corresponding, for example, here to a cell of the NW network.

Under normal operating conditions, the access points 2 are assumed here to have a continuous power supply, for example via a mains power supply (SRC) distributing urban electricity, in a manner known per se. They also have a backup power supply (BATT), such as a battery charged by photovoltaic panels.

These assumptions are not limiting in themselves and the invention applies in other contexts, typically to other types of fixed or mobile networks (e.g. 4G, 6G, WLAN (for "Wireless Local Area Network"), etc.), incidentally to other types of access points allowing access to these networks and other coverage areas of these access points, to other sources of electrical energy supplying these access points, or to other configurations of system 1 and to other purposes than the management of the electrical consumption of the access points 2 of the NW network.

According to the invention, system 1 further comprises at least one user device or UE 3, conforming to the invention, and located within the coverage area of one of the access points 2 managed by system 1. In the example illustrated on the FIG. 1 , user equipment 3 is located in the ZC-1 coverage area of base station 2-1.

In the embodiment described here, access point 2 (that is, in the example considered in the FIG. 1 , the base stations 2-1, 2-2 and 2-3) and the user equipment 3 conforming to the invention have the hardware architecture of a computer 4, as represented in the FIG. 2 This hardware architecture relies in particular on a processor (PROC), a random access memory (MEM), a read-only memory (ROM), a non-volatile memory (NVM), and COM means of communication via, in particular, the NW network or any other network.

The non-volatile NVM memory constitutes a recording medium according to the invention, readable by the PROC processor and on which a computer program according to the invention is recorded.

• un module 2A de basculement configuré pour, suite à un événement déterminé relatif à au moins un équipement du réseau détecté dans le réseau, basculer le point d’accès 2 dans un mode de fonctionnement dit dégradé dans lequel le point d’accès 2 fonctionne à capacité réduite ; et
• un module 2B d’annonce configuré pour annoncer sur la zone de couverture ZC du point d’accès 2 le mode de fonctionnement dégradé dans lequel le point d’accès 2 est basculé par son module 2A de basculement.

This program, denoted PROG2 when the hardware architecture of computer 4 is that of an access point 2 conforming to the invention, is stored in the NVM non-volatile memory and comprises instructions defining the main steps of a management process according to the invention. More specifically, it defines the functional modules of access point 2 (represented on the FIG. 1 ), which rely on and/or control all or part of the PROC, MEM, ROM, NVM, and COM components of computer 4 mentioned previously. These functional modules include, in particular, in the embodiment described here:

• a failover module 2A configured to, following a specific event related to at least one network device detected in the network, switch access point 2 into a so-called degraded operating mode in which access point 2 operates at reduced capacity; and
• an advertising module 2B configured to advertise on the coverage area ZC of access point 2 the degraded operating mode into which access point 2 is switched by its failover module 2A.

It should be noted that there are no limitations attached to the entity detecting this event. The event in question can be detected by access point 2 itself or by another entity on the network (not shown on the diagram). FIG. 1 ), such as for example an OAM (for "Operations, Administration and Management") entity for the operations, administration and management of the NW network, controlled by the NW network operator, which reports the detection of the event to access point 2 or sends it a failover command to a limited capacity operating mode.

Furthermore, there are no limitations on the nature of the event that can trigger a switchover of access point 2 to a reduced-capacity operating mode. Thus, in the illustrative example of managing the power consumption of access point 2 considered here, such an event could be an anomaly (i.e., a deviation from nominal operation) affecting access point 2 and related to its power supply. Examples of such anomaly include a power outage (which may be unexpected or scheduled), a temporary switchover of access point 2 to its backup power supply (BATT), a reduction in the amount of electrical power available to access point 2, or an insufficient amount of electrical power available to it (compared to an unlimited supply such as that provided by the SRC power supply), etc.

These are, however, only illustrative, non-limiting examples of the invention. The invention can be applied to other events detected in the NW network, such as an anomaly concerning the backhaul link connecting access point 2 to the core of the NW network, a temporary switchover from a fiber backhaul link to a backup backhaul link with a lower capacity, such as a microwave backhaul link, a failure affecting one or more pieces of equipment in the NW network infrastructure, etc.

The functions of modules 2A and 2B are described further later with reference to the steps of the management process according to the invention.

• un module 3A de réception, configuré pour recevoir, lorsque l’équipement utilisateur 3 se trouve dans la zone de couverture ZC d’un point d’accès 2 du réseau NW, une annonce faite par celui-ci sur sa zone de couverture du mode de fonctionnement dégradé dans lequel le point d’accès 2 fonctionne à capacité réduite et a basculé le cas échéant ; et
• un module 3B de déclenchement, configuré pour déclencher au moins une action de prise en compte du mode de fonctionnement dégradé du point d’accès 2. Des exemples de telles actions sont décrites plus en détail ultérieurement.

When the hardware architecture of the computer 4 is that of a user device 3 conforming to the invention, the program stored in the non-volatile memory NVM is a PROG3 program comprising instructions defining the main steps of a communication method according to the invention. More specifically, it defines the functional modules of the user device 3 (represented on the FIG. 1 ), which rely on and/or control all or part of the PROC, MEM, ROM, NVM, and COM components of computer 4 mentioned previously. These functional modules include, in particular, in the embodiment described here:

• a 3A receiving module, configured to receive, when user equipment 3 is within the coverage area ZC of an access point 2 in the NW network, an announcement made by the latter within its coverage area of the degraded operating mode in which access point 2 is operating at reduced capacity and has failed over if necessary; and
• a 3B triggering module, configured to trigger at least one action to take into account the degraded operating mode of access point 2. Examples of such actions are described in more detail later.

The functions of modules 3A and 3B are described further below with reference to the steps of the communication process according to the invention.

There FIG. 3 represents the main steps of a management process according to the invention, as implemented by an access point 2 of the system 1, for example by the base station 2-1, in a particular embodiment.

We assume here, as a preliminary matter, that base station 2-1 is nominally (i.e., under normal operating conditions) supplied with continuous and (virtually) unlimited electrical power via its SRC mains supply, which distributes urban electricity. These normal operating conditions allow it to provide, in a manner known per se, a certain quality of service (referred to as nominal) to user equipment located within its coverage area, within the limits of its design. It thus operates in a nominal operating mode MOD-NOM (step E00).

We now assume that the nominal power supply to Base Station 2-1 via the SRC mains supply is disrupted, for example, the SRC mains supply to Base Station 2-1 is temporarily suspended due to a technical incident, and the power supply to Base Station 2-1 automatically switches to its backup power supply (BATT), at least for a limited time depending on the size of this backup power supply and the amount of energy available to it. Base Station 2-1 detects this anomaly affecting its nominal power supply and the switchover to its backup power supply (step E10) in a way that is known per se and not detailed here. It also incidentally detects that it has a limited amount of electrical energy available to operate (and therefore perform its functions) within the NW network.

In the embodiment described here, following this detection, base station 2-1 determines that it has reduced and limited power supply and decides to switch (or is configured to switch), via its 2A failover module, to a lower power consumption mode. More specifically, according to the invention, base station 2-1 switches via its 2A failover module to a MOD-LESS degraded operating mode in which it operates at reduced capacity (step E20). Such a switchover aims to extend its autonomy, and therefore its ability to provide essential services to user equipment within its ZC-1 coverage, such as emergency services, VoIP services, etc., when it does not have nominal access (i.e., under normal conditions) to electrical power. The MOD-LESS degraded operating mode activated by base station 2 can therefore be considered, in the example considered here, as a power-saving mode.

Base station 2-1 can be configured to switch to a given MOD-LESS degraded operating mode based on its context, and more specifically, its power status, or to switch to a MOD-LESS degraded operating mode that it selects based on one or more predefined criteria. Such criteria may include the context (e.g., power status) in which base station 2-1 operates, the nature and/or severity of the detected anomaly that led to a switch to a degraded operating mode (e.g., based on the charge level of the backup battery BATT), the expected duration of the anomaly (e.g., if the anomaly is related to scheduled maintenance), the current traffic load in the ZC-1 coverage area, and so on.

In the embodiment described here, Base Station 2-1 is configured to switch to a MOD-LESS degraded operating mode chosen from one of the operating modes defined in Table 1 below. According to this example, depending on the degraded operating mode chosen, a degradation is expected for at least one user device located within Base Station 2's ZC-1 coverage area (typically for user device 3), of at least one of the following: latency, throughput, number of Physical Resource Blocks (PRBs) allocated to that user device, transmitted signal power, and/or number and/or types of services accessible by that user device. These degraded operating modes are particularly relevant for enabling Base Station 2-1 to adapt its traffic load to accommodate its power limitations.

Fashions Features Mode 1

• Increased latency
• Reduced coverage area capacity (e.g., cell)

Mode 2

• Limited available bandwidth (e.g., DL 2 Mbps / UL 1 Mbps)
• Increased latency

Mode 3

• Limited number of physical resource blocks (PRBs) per UE
• Increased latency

Mode 4

• Limited accessible services: voice and SMS only

Mode 5

• Limited accessible services: Emergency call and SMS only

In the example in Table 1, the higher the mode index, the greater the expected degradation of the quality of service provided to user equipment located in the coverage area of base station 2-1.

Each degraded operating mode defined at the 2-1 base station level corresponds to a reduction in the resources available to the 2-1 base station to perform its functions within its ZC-1 coverage area, compared to its nominal operation. This may correspond, for example, to the deactivation of one or more capacity bands if the 2-1 base station has multiple frequency bands, to a reduction in its transmission power, to the spacing of periodic signal transmissions, to the deactivation of some of its antennas when the 2-1 base station is multi-antenna, to discontinuous transmission/reception (DTX/DRX), etc., or other mechanisms known to those skilled in the art.

Thus, for example, by way of illustration and not limitation, one can imagine that Mode 1 is used to cope with a degradation of the backhaul link of base station 2-1. The use of a backup link increases latency and therefore leads to a reduction in the capacity of base station 2-1.

As another example, Mode 3 can be activated at base station 2-1 when it experiences a limitation in available electrical power. To compensate for this limitation, some frequency bands can be deactivated, either partially or completely, typically to retain only the lowest frequency bands or to use certain frequency bands only a portion of their bandwidth (for example, for a 100 MHz band, only 50 MHz could be used). This results in a reduction of the radio resources available at base station 2-1 to handle user traffic within its coverage area.

As another example, Mode 5 can correspond to a situation in which the base station is powered by battery for an indefinite period. Therefore, it is configured to provide a minimum service (e.g., SMS, emergency calls) for as long as possible.

Following the selection of a suitable MOD-LESS degraded operating mode and the switchover of base station 2-1 to this MOD-LESS degraded operating mode, base station 2-1 announces its reduced-capacity operation to user equipment located within its ZC-1 coverage area (step E30) via its 2B advertising module (step E30). More specifically, in the embodiment described here, module 2B periodically broadcasts a message within its ZC-1 coverage area, including an information signal, for example, named "CAPA-LOW," which represents the MOD-LESS degraded operating mode into which base station 2-1 has switched. This information signal is, for example, inserted into a system information block (SIB) broadcast within the ZC-1 coverage area, in a manner known to those skilled in the art and not described here. Further details on such system information blocks are given for example in the 3GPP TS 38.331 document entitled "3GPP; TSGRAN; NR; Radio Resource Control (RRC) protocol specification (Release 18)" v18.3.0, September 2024, in particular in paragraph 5.2.

• une information LEVEL représentative d’un niveau de dégradation induit par le mode de fonctionnement dégradé MOD-LESS dans lequel est basculé la station de base 2-1 : dans l’exemple précité de la Table 1, ceci peut consister à indiquer l’indice du mode choisi (ex. LEVEL= 2), à supposer que les équipements utilisateurs du réseau NW soient configurés pour être en mesure d’interpréter cet indice ;
• une information R-CELL représentative d’au moins une zone voisine de la zone de couverture ZC-1 de la station de base 2-1, couverte par au moins une autre station de base du réseau NW qui n’est pas basculée dans un mode de fonctionnement dégradé ou qui est basculée dans un mode de fonctionnement dégradé présentant un niveau de dégradation moindre par rapport au mode de fonctionnement dégradé MOD-LESS de la station de base 2-1. Cette information peut prendre la forme d’une liste d’identifiants de stations de base susceptibles d’être re-sélectionnées par un équipement utilisateur 3 se trouvant dans la zone de couverture ZC-1, ou de fréquences associées à ces stations de base, ou d’identifiants de cellules couvertes par ces stations de base, etc. Typiquement, dans l’exemple envisagé ci-dessus du mode 2 de fonctionnement dégradé choisi pour la station de base 2-1 et dans la configuration illustrée sur laFIG. 1, une telle information peut comprendre au moins une station de base parmi les stations de base 2-2 et 2-3 qui fonctionne à capacité nominale ou dans un mode de fonctionnement dégradé d’indice 1 dans la Table 1 ;
• une information TTR représentative d’une durée de basculement de la station de base 2-1 dans le mode de fonctionnement dégradé MOD-LESS. Si par exemple le basculement de la station de base 2-1 dans un mode de fonctionnement dégradé est liée à une opération de maintenance de durée limitée sur le réseau électrique, connue de l’opérateur du réseau NW, on peut envisager un basculement de la station de base 2-1 dans le mode MOD-LESS limité à cette durée ;
• une information ACT représentative d’un comportement à adopter par les équipements utilisateurs se trouvant dans la zone de couverture ZC-1 en réponse au fonctionnement à capacité réduite de la station de base 2-1. Cette information peut être explicite ou déduite par les équipements utilisateurs de l’information de niveau de dégradation (par exemple de l’indice du mode de fonctionnement dégradé) moyennant une configuration appropriée de ces derniers. Ainsi dans l’exemple du mode 2 sélectionné pour la station de base 2-1, un tel comportement à adopter peut comprendre l’annulation, par un équipement utilisateur se trouvant dans la zone de couverture ZC-1 et attaché à la station de base 2-1, de tout trafic en tâche de fond (par exemple de type mise à jour de logiciels, mise en cache, téléchargement automatique de contenus, pooling, etc.) ainsi que de trafic associé à des gros volumes (de type streaming, téléchargement supérieur à 10Mo, etc).

In the embodiment described herein, the system information block comprising the "CAPA-LOW" information signal informing user equipment of the reduced capacity operation of base station 2-1 further includes at least one of the following additional information:

• a LEVEL information representative of a level of degradation induced by the degraded operating mode MOD-LESS into which the base station 2-1 is switched: in the aforementioned example from Table 1, this may consist of indicating the index of the chosen mode (e.g. LEVEL= 2), assuming that the user equipment of the NW network is configured to be able to interpret this index;
• R-CELL information representative of at least one area adjacent to the ZC-1 coverage area of base station 2-1, covered by at least one other base station in the NW network that is not switched to a degraded operating mode or that is switched to a degraded operating mode with a lower level of degradation compared to the MOD-LESS degraded operating mode of base station 2-1. This information may take the form of a list of base station identifiers that can be re-selected by a user device 3 located in the ZC-1 coverage area, or frequencies associated with these base stations, or identifiers of cells covered by these base stations, etc. Typically, in the example considered above of the degraded operating mode 2 chosen for base station 2-1 and in the configuration illustrated on the FIG. 1 , such information may include at least one base station among base stations 2-2 and 2-3 which is operating at full capacity or in a degraded operating mode indexed 1 in Table 1;
• a TTR information representative of a switchover time of base station 2-1 in the degraded operating mode MOD-LESS. If, for example, the switchover of base station 2-1 in a degraded operating mode is linked to a maintenance operation of limited duration on the electrical network, known to the NW network operator, a switchover of base station 2-1 in MOD-LESS mode limited to this duration can be considered;
• An ACT (Active Communication) message represents the behavior to be adopted by user equipment located within the ZC-1 coverage area in response to the reduced capacity operation of base station 2-1. This information can be explicit or inferred by the user equipment from the degradation level information (e.g., the degraded operating mode index) through appropriate configuration. Thus, in the example of mode 2 selected for base station 2-1, such behavior might include the cancellation, by a user device located within the ZC-1 coverage area and connected to base station 2-1, of all background traffic (e.g., software updates, caching, automatic content downloads, pooling, etc.) as well as traffic associated with large volumes (e.g., streaming, downloads exceeding 10 MB, etc.).

Of course, this is a non-exhaustive list of information that may accompany the announcement of base station 2-1, and other information may be considered as a variant or complement to the aforementioned information.

Furthermore, in the embodiment described here, periodic dissemination of the degraded operating mode into which base station 2-1 is switched is envisaged in a system information block. However, other ways of announcing the reduced capacity of base station 2-1 can be considered, for example by using a message other than a system information block, or with a variable period depending on the traffic load on the ZC-1 coverage area over time or the severity of the detected anomaly, or even aperiodically (e.g., on an ad hoc basis), etc.

In the embodiment described here, base station 2-1 maintains its degraded operating mode until the event that caused it to switch to reduced capacity operation disappears; in other words, in the illustrative example considered here, until its mains power supply is restored (test step E40). It then resumes its nominal operating mode and announces it on its coverage area ZC-1 in the same or similar manner as described previously for the MOD-LESS degraded operating mode (step E50).

However, in another embodiment, it is possible to consider that if the energy situation of base station 2-1 worsens (for example, the level of its backup battery BATT is below a certain threshold), base station 2-1 switches to an even more degraded operating mode and announces this new, even more degraded operating mode in a similar or identical way to what was previously described for the MOD-LESS degraded operating mode.

There FIG. 4 represents the main steps of the communication process, as implemented, in a particular embodiment, by a user device of system 1 located in the coverage area ZC-1 of base station 2-1 (for example user device 3) and receiving the advertisement from base station 2-1.

According to the invention, upon receiving, via its receiving module 3A, the announcement broadcast by base station 2-1 (step F10), the user equipment 3 is required to adapt its behavior to the reduced capacity operating mode of base station 2-1 (step F20).

More specifically, user equipment 3 triggers, via its trigger module 3B, at least one action to take into account the MOD-LESS degraded operating mode of base station 2-1.

Such an action can be understood as previously mentioned in the announcement of base station 2-1 (ACT information mentioned previously).

Alternatively, user equipment 3 can be configured with a number of actions to be taken depending on the index of the degraded operating mode into which base station 2-1 has switched.

The actions in question can be chosen based on the level of degradation likely to affect the quality of service provided to user equipment located within the ZC-1 coverage area and induced by the MOD-LESS degraded operating mode of base station 2-1. For example, different actions can be associated with the different possible degraded operating modes of base station 2-1 (see examples in Table 1). It should be noted, however, that some actions may apply to all modes.

• une re-sélection d’une autre station de base du réseau NW qui n’a pas basculé dans un mode de fonctionnement dégradé ou qui a basculé dans un mode de fonctionnement dégradé présentant un niveau de dégradation moindre susceptible d’affecter une qualité de service fournie aux équipements utilisateurs se trouvant dans sa zone de couverture. Une telle re-sélection peut être opérée par exemple parmi la liste R-CELL fournie le cas échéant dans l’annonce de la station de base 2-1 ;
• une annulation et/ou une adaptation d’au moins une partie du trafic échangé entre l’équipement utilisateur 3 et la station de base 2-1, comme par exemple tout le trafic « non essentiel » ou non prioritaire en tâche de fond (par exemple de type mise à jour de logiciels, mise en cache, téléchargement automatique de contenus, pooling, etc.) ou le trafic associé à de gros volumes de données (de type streaming, téléchargement supérieur à 10Mo, etc) ;
• une réduction d’un nombre et/ou d’au moins un type de services accessibles par un utilisateur dudit équipement utilisateur (par exemple, une restriction à des services d’urgence) ;
• une notification d’un utilisateur de l’équipement utilisateur 3 ;
• etc.

Such actions may include, but are not limited to:

• a re-selection of another base station in the NW network that has not switched to a degraded operating mode or that has switched to a degraded operating mode with a lower level of degradation likely to affect the quality of service provided to user equipment located in its coverage area. Such a re-selection can be carried out, for example, from the R-CELL list provided, where applicable, in the base station 2-1 announcement;
• a cancellation and/or adaptation of at least part of the traffic exchanged between user equipment 3 and base station 2-1, such as all "non-essential" or non-priority background traffic (e.g., software updates, caching, automatic content downloads, pooling, etc.) or traffic associated with large volumes of data (e.g., streaming, downloads greater than 10MB, etc.);
• a reduction in the number and/or at least one type of services accessible by a user of said user equipment (for example, a restriction to emergency services);
• a notification from a user of user equipment 3;
• etc.

Other actions can of course be considered, at the initiative of the user of user equipment 3 for example, or depending on the context in which user equipment 3 is located, etc.

Examples of actions based on the degraded operating mode activated at base station 2-1 are given in the following Table 2, which echoes the examples of modes considered in Table 1. These actions allow for an effective adaptation of the traffic load of base station 2-1 in its coverage area ZC-1 according to its available capacity to accommodate the reduction of this capacity.

Fashions Actions Regardless of the mode

• Notifier l’utilisateur de l’équipement utilisateur au moyen d’un message préétabli, par exemple :« En raison d’un incident technique, votre connexion au réseau est temporairement limitée ». Si la durée TTR est disponible indiquer : «Durée prévisible de l’incident : TTR»

Alternatively: regularly test the neighboring areas listed in the R-CELL announcement, if applicable.

• Notify the user of the user's equipment using a predefined message, for example: "Due to a technical incident, your network connection is temporarily limited." If the TTR duration is available, indicate: " Expected duration of the incident: TTR "

Mode 1

• Cancel all background traffic (updates, caching, automatic content downloads, pooling)
• Notify the user: "Connection temporarily limited capacity - please reduce your usage"

Modes 2 and 3

• Cancel all background traffic (updates, caching, automatic content downloads, pooling)
• Notify the user: "Connection with temporarily limited capacity and bandwidth - please limit your usage to the bare minimum."

Mode 4

• Stop initiating new data sessions or video calls – close an existing session or video call
• Notify the user: "Connection severely limited – Voice calls and SMS only"

Mode 5

• Stop initiating new data sessions or video calls – close an existing session or video call
• Stop initiating new voice calls – end an already active call
• Notify the user: "Extremely limited connectivity – Emergency calls and SMS only"

Implementing such actions at the user equipment 3 level presents no difficulty for a person skilled in the art. For example, the limitations of modes 2 and 3 indicated in Table 2 can be achieved through appropriate configuration of the scheduler on user equipment 3 and/or the implementation of traffic adaptation measures. For modes 3 and 4, the recommended actions can be implemented by configuring the possible access categories or access classes for user equipment 3, as described, for example, in the 3GPP TS 24.501 document entitled "3GPP Technical Specification Group Core Network and Terminals; Non-Access-Stratum (NAS) protocol for 5G System (5GS); Stage 3; Release 18”, v18.8.0, September 2024. Furthermore, notifications to the user of user equipment 3 can be made in a manner known per se via the screen of user equipment 3 or any other interface (e.g. speaker) allowing interaction with the user.

Thus, thanks to the appropriate behavior of user equipment 3, the traffic exchanged with base station 2-1 can be reduced, which allows the latter to control, in the example considered here, its energy consumption.

Claims (15)

Method for managing an operating mode of an access point (2-1) of a telecommunications network (NW), said method comprising, following a specified event relating to at least one network device detected in the network (E10):
- a step (E20) of switching the access point into a so-called degraded operating mode in which the access point operates at reduced capacity; and
- a step (E30) of announcing, over a coverage area of the access point, said degraded operating mode of the access point. Management method according to claim 1 wherein said determined event is an anomaly affecting the operation of said at least one network equipment. Management method according to claim 1 or 2 wherein said anomaly relates to a power supply of the access point or a connection link of the access point to a core network of said telecommunications network. Management method according to any one of claims 2 or 3 wherein the degraded operating mode into which the access point is switched is selected according to the nature and/or severity of the detected anomaly. Management method according to any one of claims 1 to 4 wherein the degraded operating mode into which the access point is switched includes a degradation, for at least one user device located in said coverage area of the access point, of at least one element among a latency, a throughput, a number of allocated physical resource blocks, a transmitted signal power and/or a number and/or types of accessible services. A management method according to any one of claims 1 to 5, wherein said announcement step includes at least one piece of information from:

• information (LEVEL) representative of a level of degradation induced by the degraded operating mode into which the access point is switched;
• information (R-CELL) representative of at least one area adjacent to the coverage area of the access point, covered by at least one other access point in the network that is not switched to a degraded operating mode or that is switched to a degraded operating mode with a lower level of degradation;
• a representative information (TTR) indicating the duration of the access point switching into said degraded operating mode;
• information (ACT) representative of a behavior to be adopted by at least one user device located in the coverage area of the access point.

Management method according to any one of claims 1 to 6 wherein the announcement step (E30) is implemented periodically on said coverage area. Management method according to any one of claims 1 to 7 wherein during the announcement step (E30), the degraded operating mode of the access point is announced in a system information block broadcast by the access point over its coverage area. A method of communication by a user device (3) located within the coverage area of an access point of a telecommunications network, said method comprising:

• a step (F10) of receiving an announcement made by an access point within its coverage area, of a so-called degraded operating mode in which the access point operates at reduced capacity and has switched over; and
• a step (F20) to trigger at least one action to take into account the degraded operating mode of the access point.

Communication method according to claim 9 wherein at least one of said triggered actions depends on a level of degradation likely to affect a quality of service provided to said user equipment and induced by the degraded operating mode into which the access point has switched. Communication method according to claim 9 or 10 wherein said at least one action includes a re-selection of another access point of the network which has not switched to a degraded operating mode or which has switched to a degraded operating mode exhibiting a lower level of degradation likely to affect a quality of service provided to said user equipment. A communication method according to any one of claims 9 to 11, wherein at least one of said triggered action is chosen from:

• a cancellation and/or adaptation of at least part of the traffic exchanged between said user equipment and said access point;
• a reduction in the number and/or at least one type of services accessible by a user of said user equipment;
• a notification from a user of said user equipment.

Access point (2-1) of a telecommunications network comprising:
- a failover module (2A) configured to, following a specific event relating to at least one network device detected in the network, switch the access point into a so-called degraded operating mode in which the access point operates at reduced capacity; and
- an advertising module (2B) configured to advertise over a coverage area of the access point the degraded operating mode into which the access point is switched by the failover module. User equipment (3) of a telecommunications network comprising:

• a receiving module (3A) configured to receive, when said user equipment is within the coverage area of an access point of said network, an announcement made by said access point within said coverage area of a so-called degraded operating mode in which the access point operates at reduced capacity and has failed over; and
• a trigger module (3B), configured to trigger at least one action to take into account the degraded operating mode of the access point.

System (1) comprising at least one access point (2-1) of a telecommunications network according to claim 13 and at least one user device (3) according to claim 14 located in a coverage area of the access point.