Method for delivering information, selecting method, and entities configured to implement these methods

Abstract

The invention relates to a method for delivering information relating to a first device (NF3,...,NFN) of a communication network, the first device hosting a network function implementing at least one functionality in the network in a service area covering at least one zone that is referred to as an elementary zone, this method comprising: - a step of obtaining, for at least one elementary zone covered by said service area of the first device, a weight assigned to this elementary zone, said weight being a real number higher than or equal to 0; and - a step of delivering, to a second device of the network, all or some of said weights obtained in the obtaining step.

Description

Description Title of the invention: Method of providing information, method of selection, and entities configured to implement these methods Prior art

[0001] The invention belongs to the general field of telecommunications.

[0002] It relates more specifically to the management of devices implementing various functionalities or services in a communication network, such as for example in a 5G core network (or "5GC" for "5G Core network" in English) as defined by the 3GPP standard. Such devices are, for example, in this context, devices hosting network functions (or NF for "Network Functions" in English) implementing functionalities such as network access, user mobility or even the management of sessions established in the network, the storage and publication of network function profiles, etc. Several instances of the same network function can be deployed within a 5G core network, each instance being responsible for serving a given geographical sector, referred to here as a "service area", consisting for example of a group of radio cells.

[0003] In order to optimize procedures within the 5G core network, NF functions may call upon a specific NF function responsible for collecting and analyzing network data, called a NWDAF (NetWork Data Analytics Function). The NWDAF provides the network NF functions that request it with statistical analyses and / or predictions on the behavior of the network, in particular in terms of quality of service and / or the behavior of user equipment (or UE for "User Equipment" in English). The predictions may be global, i.e. established at the network, server, application or region level (e.g. network resource load rate, average quality of service, number of users connected to the network or active sessions, etc.), or individual, i.e. relating to a particular UE or group of UEs (e.g.future location of a UE, volume of a future communication session of a UE, etc.). Statistical analyses and predictions are carried out on the basis of information that the NWDAF function collects from other NF functions in the network and / or from nodes in the radio access network via the network management entity in charge of operations, administration and maintenance, also known as the OAM entity (for "Operations, Administration and Maintenance" in English).

[0004] As mentioned above, multiple NWDAF instances can be deployed within the 5G core network, each one being responsible for serving a specific geographical service area. When a network NF (e.g., an Access and Mobility Management Function (AMF)) wishes to access the functionalities implemented by a NWDAF, in accordance with the 3GPP standard, it queries the network's Network Repository Function (NRF). This NRF maintains, in a known manner, a "catalog" of the profiles of the NF instances of the 5G core network, each profile associated with an instance of an NF containing various information such as the identity of the instance, the type of NF implemented by the instance, its service characteristics, its service area, etc.

[0005] Thus, when a so-called "consumer" NF function (or more commonly "consumer" in English) wishes to access the functionalities offered by another so-called "provider" NF function (or more commonly "provider" in English), the "consumer" NF function sends a discovery request to the NRF function specifying one or more search criteria characterizing the "provider" NF function with which it wishes to communicate. Such a search criterion may be in particular the type of NF function sought, i.e. NWDAF in the example mentioned above, the type of statistics and / or predictions desired, an area of ​​interest served by the NF function sought, etc.The NRF function, based on the NF function profiles available to it, then responds to the discovery request by identifying one or more so-called “candidate” instances meeting the search criterion(s) specified in the discovery request: if several candidate instances are identified, the NF consumer function must then select one to meet its needs.

[0006] The procedure for selecting an NWDAF network function instance (hereinafter referred to as "NWDAF instance" for the sake of simplification) by a consumer NF is described in 3GPP TS 23.288, "Architecture Enhancements for 5G system (5GS) to support network data analytics services (Release 17)", V17.4.0, March 2022, in section 5.2. This procedure prescribes choosing an NWDAF instance whose service area encompasses an area of ​​interest defined by the consumer NF using, for example, TAI (Tracking Area Identity) identifiers broadcast by the cells present in this area of ​​interest. Such an area of ​​interest is, for example, the area in which a UE is located for which the consumer NF wishes to receive statistical analyses and / or predictions from the NWDAF.

[0007] If this is not possible (e.g. the TAIs of the area of ​​interest are not known to the NF consumer function, the area of ​​interest is not fully covered by a service area), it is appropriate to choose an NWDAF instance with an aggregation capacity (i.e. which is capable of collecting and aggregating the statistical analyses and predictions provided by several other NWDAF instances) covering the widest possible geographical area.

[0008] The selection procedure defined in TS 23.288, however, does not provide any guidance for selecting an NWDAF instance when the area of ​​interest of the NF consumer function is covered by the service areas of several distinct candidate NWDAF instances. Figure 1 illustrates such a situation.

[0009] In this figure, four service areas Z1, Z2, Z3 and Z4 are respectively assigned to four candidate NWDAF instances, referenced by NWDAF1, NWDAF2, NWDAF3 and NWDAF4. We consider a consumer NF function NF1 wishing to obtain predictions relating to a user equipment UE1; the function NF1 thus defines as area of ​​interest Z1, the area in which the user equipment UE1 is located. In the example illustrated in Figure 1, this area of ​​interest Z1 is located in the service areas Z1, Z2 and Z4 of the candidate instances NWDAF1, NWDAF2 and NWDAF4. According to the selection procedure mentioned described in document TS 23.288, the consumer function NF1 can indifferently choose any one of the candidate instances NWDAF1, NWDAF2 and NWDAF4 to address its requests for predictions relating to the user equipment UE1.

[0010] It should be noted, however, that user equipment UE1 is located at the edge of the service areas of candidate instances NWDAF1 and NWDAF4. If user equipment UE1 moves out of one or the other of these service areas, this leaves little time for the corresponding NWDAF instance to collect data on user equipment UE1 in order to produce the predictions requested by the consumer function NF1. It is therefore clear that choosing candidate instance NWDAF2, rather than candidate instances NWDAF1 and NWDAF4, is more judicious in this context.

[0011] A similar situation may arise when, during the data collection and / or analytical calculation period, an NWDAF instance (hereinafter "source" NWDAF instance) selected by a consumer NF function is required to transfer all or part of its statistical analysis and / or prediction subscriptions to another NWDAF instance (hereinafter "target" NWDAF instance). The reason for such a transfer may be internal (e.g., load balancing, graceful shutdown of the source NWDAF instance, etc.) or external (e.g., mobility of the user equipment targeted by the statistical analysis and / or prediction required by the consumer NF function). This transfer procedure is described in TS 23.288, paragraph 6.1B.The handover to the target NWDAF instance may be preceded by a pre-preparation phase to trigger data collection at the target NWDAF instance before the source NWDAF instance is no longer effective (e.g., before the UE1 user equipment subject to statistical analyses and / or predictions required by the NF consumer function leaves the service area of ​​the source NWDAF instance). However, TS 23.288 does not provide any indication of the event triggering this pre-preparation phase.

[0012] The transfer procedure can be initiated by the source NWDAF instance, which must then select the target NWDAF instance which will serve as a relay to establish the statistical analyses and / or predictions required by the NF consumer function. The discovery of candidate NWDAF instances for transfer by the source NWDAF instance is carried out by sending a discovery request to the NRF function, as described previously, and the selection of an NWDAF instance from among the candidate NWDAF instances identified by the NRF function is carried out according to the selection procedure defined in paragraph 5.2 of document TS 23.288. The source NWDAF instance is therefore likely to encounter the same selection difficulties mentioned previously when several service areas assigned to distinct candidate NWDAF instances cover the area of ​​interest defined by the source NWDAF instance. Statement of the invention

[0013] The invention makes it possible to overcome the aforementioned drawbacks by proposing a method for providing information relating to a first device of a communication network, this first device hosting a network function implementing at least one functionality in the network in a service area covering at least one so-called elementary area, this method comprising: a step of obtaining, for at least one elementary area covered by the service area of ​​the first device, a weight assigned to this elementary area, this weight being a real number greater than or equal to 0; and a step of providing to a second device of the network all or part of the weights obtained during the obtaining step.

[0014] Correlatively, the invention also relates to a so-called provision entity of a communication network, configured to provide information relating to a first device of the network, the first device hosting a network function implementing at least one functionality in the network in a service area covering at least one so-called elementary area. The provision entity comprises: an obtaining module, configured to obtain, for at least one elementary area covered by the service area of ​​the first device, a weight assigned to this elementary area, this weight being a real number greater than or equal to 0; and a provision module, configured to provide to a second device of the network all or part of the weights obtained by the obtaining module.

[0015] The providing entity may be the first device or another device in the network. The first device is typically a service provider device hosting a network function. For example, the first device may host a network function for collecting and analyzing network data; in the specific context of a 5G network, such a first device is a device hosting an NWDAF network function.

[0016] The second device is typically a service consumer device or network consumer device wishing to access the services and / or functionalities offered by the first device. Such a consumer device is, for example, a device hosting an AMF network function wishing to obtain statistics and / or predictions from a device hosting an NWDAF network function. However, it may be a device other than a consumer device, such as, for example, a device configured to manage the devices hosting the various network functions, and in particular to maintain and publish the profiles of these devices. In the context of a 5G network mentioned above, such a device is typically a device hosting an NRF network function.

[0017] Thus, the invention has a preferred but non-limiting application in the following two contexts: the first device is an NWDAF network function implementing the provision method (therefore integrating a provision entity within the meaning of the invention), and the second device to which the first device provides the weights is an NRF network function; the first device is an NWDAF network function, the provision method is implemented by an NRF network function (which then integrates a provision entity within the meaning of the invention), and the second device is a network function requesting the NRF network function (for example an AMF network function or an NWDAF network function) to select an NWDAF network function in order to establish predictions and / or statistics or to transfer subscriptions relating to such predictions and / or statistics.

[0018] Of course, these examples are given for illustrative purposes only. It should be noted that although the invention has been introduced with reference to devices hosting NRF, NWDAF and AMF network functions in a 5G core network, it can be applied in other contexts, and in particular to other network functionalities as well as to other networks (e.g. 6G network, proprietary network, etc.). The invention has a preferred application whenever a selection is necessary among several devices hosting the same network function within a network and serving service areas covering a given area of ​​interest, in other words overlapping (i.e. having an intersection) at least at the level of the area of ​​interest.

[0019] To manage such a situation and allow the selection of the device having the most suitable coverage to ensure a given network function, the invention advantageously relies on a new way of describing the service areas assigned to devices hosting network functions, geographically distributed in the network. More specifically, the invention exploits the fact that in a network, a service area assigned to such a device generally covers an integer number, greater than or equal to 1, of “elementary” areas, and thus proposes to describe each service area from the elementary areas covered by it, to which a weight is assigned, this weight being intended to be taken into account when the device in question is in competition with other devices in the network to implement the functionalities of a certain network function.For example, it is possible to consider assigning a weight to at least each elementary zone covered by the service area of ​​the first device and by at least one other service area of ​​at least one third device in the network, this third device being able to host the same network function as the first device. According to another example, each elementary zone of each service area is assigned a weight.

[0020] Such an elementary zone is typically a “unitary” geographical area associated with the network and defined for the purposes of deployment and / or operational operation of the network. For example, for a cellular network, an elementary zone may correspond to a cell of the network or to a set composed of one or more cells of the network such as a location area (more commonly known as TA or “Tracking Area” in English). Such elementary zones advantageously form, as a whole, a tiling of the entire geographical coverage area of ​​the network.Since the service areas of network devices are conventionally defined on the basis of such elementary zones, this makes it possible to adapt to the topology of the network and its deployment (it should also be noted that the dimensions of the elementary zones may differ from one geographical area to another depending on the conditions of network deployment; for example, cells of greater or lesser sizes may be considered depending on whether one is in an urban or rural environment), and / or to its operational functioning.

[0021] Furthermore, a good compromise is ensured when implementing the invention between complexity and precision: such elementary zones are indeed generally representative of the level of granularity considered when executing most of the operational mechanisms enabling the operation of the network; furthermore, it is the identifiers of these elementary zones which are conveyed in the signaling messages.

[0022] Alternatively, one can consider elementary zones that are strictly speaking independent of the network, for example geographical zones of fixed dimensions (e.g. squares of dimensions 10 km by 10 km) forming a tiling of the network coverage area.

[0023] Such a variant may be considered in particular in the context of selecting a network entity providing air traffic control for flying objects such as drones. Such an entity is, for example, in the context of a 5G network, a USS / UTM function (for “UAS Service Supplier / UAS Traffic Management” in English, UAS designating “Uncrewed Aircraft System”).

[0024] When the same elementary area is covered by service areas assigned to separate devices hosting the same network function (NWDAF network function in the situation illustrated in Figure 1), a different weight can be assigned to this elementary area for the different service areas concerned. This makes it possible to assign different priorities to the devices covering these common elementary areas (reflecting for example the preferences of the network operator), and thus to facilitate the choice of a device among the others based on these priorities. Conversely, if one does not wish to establish priority between two devices implementing the same network function, the same weight can be assigned to the elementary area for the service areas of these two devices.

[0025] This is, however, only a particular implementation choice, and other allocation policies can be considered. The invention offers great flexibility in this regard, in particular allowing the operator's preferences to be easily reflected.

[0026] Generally speaking, the weights are assigned to the elementary zones according to a strategy consistent with the selection policy that one (e.g. the network operator) wishes to implement in the network, taking into account the functionalities implemented by the devices and the context considered.

[0027] By way of illustration, in the example considered previously, if it is desired to take into account the mobility of a user equipment in a context of selection of an instance of NWDAF function which requires data to be collected over a more or less long period of time, the weight assigned to an elementary zone for the first device may depend on the distance of this elementary zone from the center of the service area of ​​the first device and / or its distance from the border (i.e. the edge) of this service area. In particular, the further the center of an elementary zone is from the center of the service area considered, or the closer this center is to the edge of the service area, the lower the weight assigned to this elementary zone may be.Typically, if a service area consists of a large number of cells arranged in a line, it may be advantageous to assign a lower weight to cells located near the ends of the line (e.g., at a distance d from the ends) than to other cells (without necessarily distinguishing weight for cells located beyond the distance d, whether or not they are close to the center of the line). By doing so, an elementary area is assigned a lower weight for the device whose furthest from the center of the service area or closest to the boundaries of the service area it is.

[0028] Of course, this is only an illustrative example, and other allocation strategies may be applied. The choice of one strategy or another may depend on various factors, such as the context of application of the invention, the network topology, the configuration of the service areas (for example, whether a service area covers only one elementary area, or a plurality of elementary areas arranged in a line), the nature of the network function implemented, etc.

[0029] Furthermore, depending on the context of application of the invention, it is possible to allocate to an elementary zone a relative weight (expressed for example in the form of a percentage), between 0 and 1, and possibly standardized over all the service zones covering this elementary zone served by devices implementing the same network function, or an absolute weight, greater than or equal to 0. Assigning non-standardized absolute weights facilitates the management of a change in these weights, in particular in the event of deletion or addition of an instance of a given network function. However, it is important to ensure that these weights are expressed on the same scale (so that they remain comparable).

[0030] It is noted that the weights may be assigned to the elementary areas covered by a service area of ​​a device in a static manner, for example they may be assigned by the network operator empirically or through experts, and then obtained through a configuration carried out by the network operator using mechanisms known per se. Alternatively, the assignment may be more dynamic, and the weights may be generated via the execution of a given algorithm or a particular analytical formula applied for example by the first device.

[0031] Furthermore, it is possible to independently assign weights to the same elementary zone for service areas of devices hosting different network functions. The assigned weights can thus be indifferently identical or different as long as they concern service areas of devices providing different functionalities in the network.

[0032] Alternatively, one can consider a correlated assignment of weights for certain features.

[0033] As previously highlighted, the invention offers great flexibility in this area depending on the policy and implementation strategy chosen by the operator.

[0034] Regardless of the policy and implementation choice used to assign weights to the elementary areas covered by a device's service area, these provide a valuable indication of the priority that the network gives to this device to implement a given network function in an area of ​​interest distributed over one or more elementary areas covered by the device's service area. This allows an informed choice, in a given context, of the best device in the network implementing a particular network function by comparing the weights assigned to the elementary areas for different devices hosting the same network function.

[0035] To make this choice, one can, for example, evaluate a metric from the weights assigned to the elementary zones covering an area of ​​interest for several devices hosting the same network function and choose the device optimizing the metric thus evaluated. Such a metric is, for example, the sum (possibly weighted) of the weights assigned to the elementary zones covered by the area of ​​interest. Alternatively, other metrics can be considered to compare the weights assigned for different devices to the elementary zones included in the area of ​​interest.

[0036] In a particular embodiment, the second device is configured to manage devices hosting network functions and all or part of the weights obtained are provided to the second device when registering or updating a profile of the first device with the second device. Such a second device is for example in a 5G core network, as mentioned above, a device hosting an NRF function, and maintaining profiles of the instances of network functions deployed in the network.

[0037] In another embodiment, the weights obtained assigned to the elementary zones covered by said service zone are obtained during a recording of a profile of the first device and all or part of said weights obtained are provided in response to a discovery request for network devices hosting a network function and meeting at least one given search criterion, said discovery request coming from the second device and said first device meeting said at least a given search criterion.

[0038] These two embodiments propose to enrich the profiles of the devices maintained within the network (for example by the NRF function for a 5G core network) and describing the characteristics of the services / functionalities offered by these devices, with the elementary areas covered by the service areas served by these devices, and the weights assigned to these elementary areas. This makes this information easily accessible to consumer devices consulting these profiles. The implementation of the invention is thus facilitated, in particular in the context of a 5G network, since it is easily integrated into the registration, update and discovery procedures already defined within such a network and does not require the definition of new structures and new procedures to store this information or to access it.

[0039] As mentioned earlier, various strategies can be considered to assign weight to an elementary area covered by a service area.

[0040] Thus, in a particular embodiment, when an elementary zone is covered by the service zone of the first device and at least one other service zone of at least one third device of the network hosting the same network function as the first device, a different weight is assigned to said elementary zone for the service zone of the first device and for said at least one other service zone of said at least one third device.

[0041] Furthermore, the weights assigned to this elementary zone for the service zone of the first device and for said at least one other service zone of said at least one third device can be chosen such that their sum is non-zero and less than or equal to 1.

[0042] A sum taken equal to 1 makes it possible to normalize the weights assigned to the same elementary zone on overlapping service areas (i.e. which have a non-zero intersection or are not disjoint) served by distinct devices. This normalization facilitates the interpretation of the metrics obtained for the different devices and the priorities reflected by these metrics.

[0043] It is however possible to refrain from carrying out such standardisation as long as the weights allocated to the same elementary zone for different devices are expressed on the same scale, which makes it possible to compare them with each other and to establish a hierarchy (i.e. a preference) where appropriate between the devices.

[0044] In a particular embodiment, the supply method further comprises: a step of updating at least one weight assigned to a said elementary zone covered by said service zone of the first device; and a step of supplying said at least one updated weight to the second device.

[0045] This embodiment makes it possible to take into account a potential evolution over time of the weights assigned to the elementary zones and to ensure that the second device is informed of this evolution. Such an evolution may be linked in particular to the appearance or disappearance in the network of network function instances, but also to other factors (e.g. load balancing, temporary unavailability of a network function instance, etc.).

[0046] In view of the above, the invention facilitates and therefore makes it possible to optimize the selection of a network device from among several providing the same network function. Thus, according to another aspect, the invention relates to a method of selection by a device of a communication network, called the fourth device, comprising: a step of sending, to a network device called the fifth device, a request of discovering network devices hosting a network function and meeting at least one given search criterion; a step of obtaining a response to said discovery request identifying at least one network device called a candidate hosting a network function and meeting said at least one given search criterion, said response comprising for each candidate device having a service area covering an area of ​​interest defined by the fourth device, a weight assigned to each area called an elementary area covered by said service area and said area of ​​interest, said weight being a real number greater than or equal to 0; and a step of selecting a said candidate device to implement at least one functionality of the network function that it hosts by comparing the weights assigned to the elementary areas covered by said area of ​​interest obtained for each candidate device identified in the response.

[0047] Correlatively, the invention also relates to a so-called selection entity of a communication network comprising: a sending module, configured to send to a network device a request for discovery of network devices hosting a network function and meeting at least one given search criterion; a obtaining module, configured to obtain a response to said discovery request identifying at least one candidate network device hosting a network function and meeting said at least one given search criterion, said response comprising, for each candidate device having a service area covering an area of ​​interest defined by the selection entity, a weight assigned to each so-called elementary area covered by said service area and said area of ​​interest, said weight being a real number greater than or equal to 0;and a selection module, configured to select a said candidate device to implement at least one functionality of the network function that it hosts by comparing the weights assigned to the elementary areas covered by the area of ​​interest obtained for each candidate device identified in the response.;

[0048] The selection method and entity benefit from the same advantages cited above as the supply method and entity according to the invention.

[0049] By way of illustration, the fourth device may be a device hosting an NF consumer function, such as for example an AMF function, the fifth device a device hosting an NRF function, and the candidate devices, devices hosting an NWDAF function. Of course, this example is given only for illustrative purposes and is not limiting of the invention. Thus, according to another example, the fourth device may be a device hosting an NWDAF function and searching for another instance of an NWDAF function to transfer its prediction and / or statistics subscriptions.

[0050] It should be noted that the first, second, third, fourth and fifth devices and candidate devices do not necessarily designate separate devices in pairs. For example, the fifth device within the meaning of the invention may be a second device within the meaning of the invention having obtained the weights associated with the elementary areas of the network covered by the service areas of a plurality of first devices within the meaning of the invention, the candidate devices identified by the fifth device being selected from among these first devices.

[0051] In a particular embodiment, the selection step comprises determining, for each candidate device of the network identified in the response, a metric from the weights obtained assigned to the elementary areas covered by the service area of ​​this candidate device and by the area of ​​interest, the selected candidate device being the one which optimizes said metric among the candidate devices identified in the response.

[0052] For example, the metric determined for a said candidate device corresponds to a weighted sum of the weights assigned to the elementary zones covered by the service area of ​​this candidate device and by the area of ​​interest defined by the fourth device.

[0053] The weighting factors used to evaluate the overall metric are positive or negative real numbers, for example rational numbers (e.g. percentages) between 0 and 1, or more generally real numbers between 0 and 1.

[0054] According to a first variant, the weighting factors used in the weighted sum are all taken equal to 1. This amounts to considering as metric the sum of the weights assigned to the elementary zones covered by the service zone of the candidate device considered and by the zone of interest.

[0055] According to a second variant, in the weighted sum, each weight assigned to an elementary zone is weighted by a probability of presence of user equipment managed by the fourth device in this elementary zone.

[0056] The probability of presence of the user equipment may come from a mobility prediction made for example by a device hosting a network data collection and analysis function such as a device hosting an NWDAF function for a 5G network. Alternatively, it may result from the observation of the presence of the user in the elementary zone.

[0057] This second variant has a preferred application in the context of a handover procedure, and more particularly when the fourth device is a device providing a certain functionality in the network in connection with a user equipment (e.g. a device hosting an NWDAF network function) and it queries the fifth device (e.g. a device hosting an NRF function) to identify a relay to which to transfer the subscriptions relating to the user equipment. The selected candidate device is then used as a relay for the fourth device to implement said functionality initially provided by the fourth device.In such a context, the second variant makes it possible to ensure that the transfer to the relay thus selected is sustainable and does not require, in the too short term, the selection of a new relay device to manage the mobility of the user equipment which could prove detrimental (it is indeed desirable, for the sake of minimizing network signaling and greater robustness, not to trigger transfer procedures too often).

[0058] Thus, in a particular embodiment, the fourth device and said selected candidate device host the same network function, and said selected candidate device is used as a relay of the fourth device to implement at least one functionality of said network function.

[0059] As mentioned above, it is possible to consider triggering a preparatory phase, as a preliminary to the transfer procedure, to avoid an overly abrupt transfer and a back-and-forth between the fourth device and the selected candidate device serving as a relay. This preparatory phase is advantageously based on the overlap of the service areas of the fourth device and the relay device. During this preparatory phase, the candidate device chosen as a relay carries out certain operations necessary for the proper execution and efficiency of the transfer: typically, for a NWDAF network function, during this preparatory phase, the candidate device chosen as relay can begin to collect and analyze network data in relation to the subscriptions which will be transferred to it. The invention, in a particular embodiment, advantageously provides indications on the appropriate moment to trigger such a preparatory phase.

[0060] More particularly, in a particular embodiment, the selection method further comprises, when the fourth device detects an entry of a user equipment that it manages in an elementary zone covered by its service area and having a weight assigned for the fourth device lower than a given threshold or lower than a weight assigned to said elementary zone for a said candidate device identified in the response to the discovery request, triggering a phase of preparation for the use of the selected candidate device as a relay for the fourth device.

[0061] This embodiment therefore advantageously indicates to the fourth device when to trigger the preparatory phase of the transfer, which makes it possible to improve the efficiency of the transfer.

[0062] In a particular embodiment, the providing and selecting methods are implemented by a computer.

[0063] 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 a supply entity in accordance with the invention and comprising instructions adapted to the implementation of a supply method as described above.

[0064] 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 a selection entity in accordance with the invention and comprising instructions adapted to the implementation of a selection method as described above.

[0065] Each of these programs may use any programming language, and may be in the form of source code, object code, or code intermediate between source code and object code, such as in a partially compiled form, or in any other desirable form.

[0066] The invention also relates to an information medium or a recording medium readable by a computer, and comprising instructions of a computer program as mentioned above.

[0067] The information or recording medium may be any entity or device capable of storing programs. For example, the medium may include a storage medium, such as a ROM, for example a CD ROM or a microelectronic circuit ROM, or a magnetic recording medium, for example a hard disk, or a flash memory.

[0068] On the other hand, the information or recording medium may be a transmissible medium such as an electrical or optical signal, which may be conveyed via an electrical or optical cable, by radio link, by wireless optical link or by other means.

[0069] The program according to the invention can in particular be downloaded from an Internet-type network.

[0070] 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 methods of providing and selecting according to the invention.

[0071] According to another aspect, the invention also relates to a system in a communication network comprising: at least one device for collecting and analyzing data from the network comprising a first provisioning entity according to the invention; a device for managing profiles of a plurality of devices hosting network functions of the network, comprising a second provisioning entity according to the invention; and a device hosting a network function of the network and comprising a selection entity according to the invention.

[0072] For example in this system: the first supply entity can be configured to provide the profile management device with the weights assigned to the elementary zones covered by a service area of ​​the collection and analysis device; and the selection entity can be configured to send a discovery request relating to a given search criterion to the management device and receive, in response to this discovery request, from the second supply entity, weights assigned to the elementary zones of the service areas of candidate devices meeting said search criterion.

[0073] The system according to the invention has the same advantages mentioned above as the provision and selection methods, and as the provision and selection entities according to the invention. It has a preferred application in the context of a 5G network, for the selection in particular of an instance of NWDAF network function whether in the context of access to the functionalities offered by this network function or in the context of a transfer procedure between two instances of NWDAF network function. In the latter case, the device of the system according to the invention hosting a network function of the network is a so-called collection and analysis device.

[0074] It may also be envisaged, in other embodiments, that the supply and selection methods, the supply and selection entities and the system according to the invention have in combination all or part of the aforementioned characteristics. Brief description of the drawings

[0075] Other characteristics and advantages of the present invention will emerge from the description given below, with reference to the appended drawings which illustrate an exemplary embodiment thereof without any limiting character. In the figures: [Fig. 1] Figure 1, already described, illustrates a situation in which multiple candidate instances are available to provide an NWDAF network function in a 5G network; [Fig. 2] Figure 2 represents, in its environment, a system in a communication network according to the invention, in a particular embodiment; [Fig. 3] Figure 3 schematically represents the hardware architecture of a computer capable of hosting any of the entities according to the invention belonging to the system of Figure 2; [Fig. 4] Figure 4 represents the functional modules of the devices of the system of Figure 2; [Fig. 5] ; [Fig. 6] Figures 5 and 6 represent respectively, in the form of flowcharts, the main stages of a supply method according to a second variant and according to a first variant embodiment of the invention; [Fig. 7] Figure 7 illustrates an example of a communications network in which the system of Figure 2 is located and different service areas served by devices of this system; [Fig. 8] Figure 8 illustrates another example of service areas assigned to two network function instances of a communications network; [Fig. 9] Figure 9 represents, in the form of a flowchart, the main steps of a selection method according to the invention; and [Fig. 10] Figure 10 also represents, in the form of a flowchart, the main steps of a selection method according to the invention when it is used within the framework of a transfer procedure. Description of the invention

[0076] Figure 2 represents, in its environment, a system 1 in accordance with the invention, in a particular embodiment in which it is located in an NW cellular communication network based on a 5GC core network as defined by the 3GPP standard (with the exceptions of arrangements linked to the implementation of the invention).

[0077] In the particular embodiment described here, the system 1 comprises a plurality of devices of the core network CN, NF1,..., NFN, N designating an integer greater than 1, hosting instances of network functions implementing various functionalities within the core network CN, each instance of network function NFn, n=1,...,N serving a service area Zn. A service area assigned to a network function instance corresponds to the geographical area served by this instance, i.e. the one over which it provides the functionality(ies) for which it is responsible within the core network CN. The definition of this service area may depend on the functionalities provided by the instance in question.

[0078] For example, for an NWDAF network function instance that collects and analyzes data about UEs, this service area can be defined based on the location of the UEs: one NWDAF instance can be assigned to the northern part of a country covered by the NW network, while another NWDAF instance can be assigned to the southern part of the country in question. For an NWDAF network function instance that collects and analyzes data collected from other NF functions (e.g., load, etc.), the service area of ​​this network function instance can be defined based on the location of these NF functions (e.g., one per region of a country covered by the NW network).

[0079] Such a service area generally covers an integer number K greater than or equal to 1 of elementary areas associated with the network (in other words, defined in the context of the network), typically an integer number K of cells of the cellular network NW, K of course being able to vary from one device to another.

[0080] Alternatively, other types of elementary areas may be considered as units for defining service areas, such as a location area or TA. Such a location area consists of one or more cells of the network and corresponds to the geographical area within which a user equipment can move without having to update its registration with the core network CN. According to yet another variant, elementary areas may be considered predefined geographical areas paving the network coverage area, defined independently of the network itself and its operation. operational, such as geographic areas of fixed dimensions such as squares with a side dimension of 10 km.

[0081] No limitation is attached to the type of network functions hosted by the devices NF1,...,NFN. In the example shown in Figure 2, it is assumed for illustrative purposes that: the device NF1 hosts an instance of a network function of type NRF, and maintains in a manner known per se a catalog of the profiles of the other network functions (i.e. of their different instances, if any) of the core network CN. Each profile associated with an instance of a network function, generally referenced by NFPROF, contains various information such as the identity of the instance, the corresponding type of network function, its service characteristics (e.g. how it can be reached, the resources it manages, etc.), its operational state (e.g. its availability, its load, etc.), the service area served by the instance, etc.The NF1 device relies, in order to keep this catalog of profiles up to date and publish all or part of the information it contains, on a plurality of services including in particular discovery and management services (including registration / deregistration / update operations) which here respectively take up the logic of the Nnrf_NFDiscovery and Nnrf_NFManagement services described in the documents 3GPP TS 23.502 entitled “Technical Specification Group Services and System Aspects; Procedures for the 5G System (5GS); Stage 2; (Release 17)”, V17.4.0, March 2022 and TS 29.510 entitled “Technical Specification Group Core Network and Terminals; 5G System; Network Function Repository Services; Stage 3; (Release 17)”, V17.5.0, March 2022 (with the modifications required by the invention detailed later).More particularly, in the embodiment described here, the device NF1 comprises a provisioning entity in accordance with the invention according to a first embodiment variant, such that all or part of the profiles maintained by the device NF1 are enriched with additional information, as detailed further below; the device NF2 hosts an instance of AMF network function, implementing functionalities for managing access and mobility in the network. In the embodiment described here, the device NF2 comprises a selection entity in accordance with the invention; and the devices NF3,...,NFN host instances of NWDAF network function, implementing functionalities for collecting and analyzing network data. Each of these devices here comprises a provisioning entity in accordance with the invention according to a second embodiment variant, as well as a selection entity in accordance with the invention.

[0082] It is noted that the CN core network comprises, in a manner known per se, other devices hosting network function instances offering other functionalities necessary for the operational functioning of the CN core network and more generally of the NW network. For example, the CN core network comprises SMF (for “Session Management Function” in English) network function instances for session management, PCF (for “Policy Control Function” in English) for flow policy management, etc.

[0083] In the embodiment described here, the devices NF1,...,NFN have the hardware architecture of a computer 2, as shown in Figure 3.

[0084] The computer 2 includes in particular a processor 3, a RAM 4, a me- read-only memory 5, a non-volatile memory 6, and communication means 7 allowing in particular the devices NF1,...,NFN of the system 1 to communicate with each other and with other devices where appropriate of the core network CN and / or more generally of the cellular network NW. These communication means 7 are based on the one hand, on a wired or wireless communication interface, known per se and not described in more detail here, but also here on one or more software interfaces based on the service or SBI (for "Service Based Interface" in English).

[0085] The non-volatile memory 6 of the computer 2 constitutes a recording medium in accordance with the invention, readable by the processor 3 and on which one or more computer programs in accordance with the invention are recorded.

[0086] More specifically, the non-volatile memory 6 of the computer 2 comprises, when it is the device NF1 (which hosts an NRF function), a recording of a computer program PROG1, comprising instructions defining the main steps of a supply method according to the invention according to the first embodiment variant.

[0087] This program PROG1 defines functional modules of a supply entity according to the first embodiment of the invention which rely on or control the hardware elements 3 to 7 of the computer 2 cited above. These modules comprise in particular, as illustrated in Figure 4: an obtaining module 8A, configured to obtain, from at least one device (playing the role of first device within the meaning of the invention) hosting a network function instance managed by the device NF1 and for which the device NF1 stores and keeps the profile up to date, a weight assigned to at least one elementary zone covered by the service zone served by this network function instance, this weight being a real number (e.g., a rational number such as a percentage) greater than or equal to 0. In the example envisaged in Figure 2, it is assumed that the obtaining module 8A obtains in particular such weights for each of the devices NF3,...,NFN of the CN core network hosting a NWDAF network function, and for each elementary zone covered by each service zone of the NF3,...,NFN devices. Alternatively, it is possible to envisage only assigning and obtaining weights (in particular non-harmful weights) for the elementary zones covered by several service zones of devices hosting the same NWDAF network function. These weights are obtained by the NF1 device and more particularly by its module 8A, when the NF3,...,NFN devices register their profiles with it and / or during an update of these profiles; the NF3,...,NFN use for this purpose here the Nnrf_NFManagement service offered by the device NF1 adapted to transmit the weights of the elementary zones, as detailed further later; and a supply module 8B, configured to supply to a consumer device of the CN core network (playing the role of second and fourth device within the meaning of the invention), when the device NF1 is queried by the consumer device by means of a discovery request relating to at least one CRIT search criterion (as defined for example in the context of the Nnrf_NFDiscovery service implemented by the device NF1), the weights obtained by the obtaining module 8A, assigned to the elementary zones covered by the service zones of the devices whose profile it stores and which meet the CRIT search criterion. Such a. search criterion CRIT includes for example a type of network function implemented by the devices (e.g. NWDAF function), an area of ​​interest that the devices must serve, etc. The weights are provided by the provisioning module 8B in the response to the search request addressed by the device NF1 to the consumer device. In the illustrative examples described below, the consumer device is considered to be the device NF2 hosting an AMF network function, and the device NF3 hosting an NWDAF network function. Of course, these examples are given for illustrative purposes only and other consumer devices may be considered as alternatives.

[0088] The operation of the modules 8A and 8B of the device NF1 is described in more detail later with reference to the steps of the supply method according to the first embodiment of the invention.

[0089] When the computer 2 is the device NF2 (which hosts an AMF function in the illustrative example envisaged here) or a device NF3,...,NFN (which hosts an instance of the NWDAF function and plays the role of second and fourth devices within the meaning of the invention), the non-volatile memory 6 of the computer 2 comprises a recording of a computer program PROG2, comprising instructions defining the main steps of a selection method according to the invention.

[0090] This program PROG2 defines functional modules of a selection entity according to the invention, integrated in the device NF2 and in each of the devices NF3,...,NFN, which rely on or control the hardware elements 3 to 7 of the computer 2 mentioned above. These modules comprise in particular, in the embodiment described here and as illustrated in FIG. 4: a sending module 9A, configured to send to a device of the core network CN, in this case here to the device NF1 hosting the network function NRF (playing the role of fifth device within the meaning of the invention), a request for discovery of devices of the core network CN hosting network functions and meeting at least one given CRIT search criterion, as described above (e.g. type of network function implemented by the device, area of ​​interest, etc.); a obtaining module 9B, configured to obtain a response to this discovery request identifying at least one device of the core network CN called candidate, hosting a network function and meeting said at least one given CRIT search criterion. This response comprises for each candidate device having a service area covering an area of ​​interest defined by the selection entity (in full in the embodiment described here), the weight stored in the profile of the candidate device assigned to each elementary area covered by said service area and by the area of ​​interest, said weight being a real number greater than or equal to 0.It is noted that, for the sake of completeness, the response may also include the weights of the elementary zones covered by the service area of ​​the candidate device which are not included in the area of ​​interest; a determination module 9C, configured to determine for each candidate device identified in the response obtained, a metric from the weights assigned to the elementary zones covered by this service area and the area of ​​interest; and a selection module 9D, configured to select a candidate device to implement at least one functionality of the network function that it hosts, by comparing the weights assigned to the elementary zones covered by the area of ​​interest obtained by the obtaining module 9B for each candidate device identified in. the response. In the embodiment described herein, the selection module 9D uses the metrics determined by the determination module 9C for the different candidate devices identified in the response and selects the candidate device corresponding to the optimal determined metric.

[0091] When stored in the non-volatile memory 6 of a device NF3,...,NFN, the program PROG2 further defines a transfer module 9E, configured to implement a transfer procedure, such as for example that described in the document 3GPP TS 23.288, and to transfer to the candidate device selected by the selection module 9D all or part of the subscriptions for which the device NF3,...,NFN is responsible. This transfer module 9E is further configured to trigger a phase of preparation of the transfer procedure with the selected candidate device, as described in more detail later.In the example of a transfer between two devices hosting an NWDAF function, this preparation phase includes in particular the transmission by the transfer module 9E to the selected candidate device of information concerning the subscriptions which will be transferred to it so that the selected candidate device is able to collect data to carry out the predictions / statistics required by these subscriptions as soon as the transfer is effective.

[0092] The operation of modules 9A-9D and where appropriate 9E is described in more detail later with reference to the steps of the selection method according to the invention.

[0093] Finally, when the computer 2 is a device NF3,...,NFN (which hosts an instance of function NWDAF and plays the role of first devices within the meaning of the invention), the non-volatile memory 6 of the computer 2 comprises a recording of a computer program PROGT, comprising instructions defining the main steps of a supply method according to the second variant embodiment of the invention.

[0094] This PROGT program defines functional modules of a supply entity according to the second embodiment variant, integrated in each NFn device, n=3,...,N, these modules relying on or controlling the hardware elements 3 to 7 of the computer 2 mentioned above. They include in particular, as illustrated in Figure 4: an obtaining module 8A', configured to obtain a weight (real number between 0 and 1) assigned to at least one elementary zone covered by the service zone served by the NFn device. In the embodiment envisaged here, a weight is assigned and obtained for each elementary zone covered by the service zone. However, as mentioned above, it is possible to envisage assigning and obtaining weights (in particular non-harmful weights) only for the elementary zones covered by several service zones of devices implementing the same network function.The obtaining module 8A' can obtain the weights in different ways: the weights can be assigned statically and empirically or by expertise by the operator of the cellular network NW (and of the core network CN) and configured at the level of the device NFn by the latter (for example via a message or an appropriate configuration interface, provided for this purpose). Alternatively, they can be evaluated dynamically by the obtaining module 8A' by applying an algorithm defined and parameterized by the network operator. Various strategies for assigning the weights to the elementary zones can be retained by the operator. As mentioned previously, these weights are intended to guide the selection of a device among several hosting the same network function; the weights are therefore assigned to the elementary zones covered by a service area. according to a strategy consistent with the selection policy that the network operator wishes to implement in the network, taking into account the functionalities offered by the device in question and the context considered. Examples of assignment strategy and assigned weights are described in more detail later; a module 8B' for supplying the weights obtained assigned to the elementary zones covered by the service area of ​​the NFn device considered. In the second embodiment variant, the supply module 8B' is configured to supply these weights to a device of the CN core network managing the devices hosting network functions and storing the profile of these devices. In the example envisaged in Figure 2, this is the NF1 device hosting the NRF function.More specifically, the supply module 8B' is configured to supply the weights assigned to the elementary zones covered by the service area of ​​the NFn device considered when registering the profile of the NFn device with the NF1 device (using the Nnrf_NFManagement service offered by the NF1 device), for example in a new attribute of this profile provided for this purpose. The attribute in question may in particular list, by means of their identifiers, the elementary zones covered by the service area of ​​the NFn device, and for each elementary zone, indicate the weight assigned by the network operator to it. Alternatively, it may be envisaged to supplement the attribute defining the service area of ​​the NFn device provided in its profile.It should be noted that if a weight assigned to an elementary zone covered by the service area of ​​the NFn device is likely to change over time, the supply module 8B' can update said weight to the NF1 device to signal this change. To this end, it can update its profile using, for example, the Nnrf_NFManagement service offered by the N Fl device.

[0095] The operation of the modules 8A' and 8B' of the devices NF3,...,NFN is described in more detail later with reference to the steps of the supply method according to the second variant embodiment of the invention.

[0096] We will now describe with reference to figures 5 and 6 respectively the different stages of the supply method as implemented by the devices NF3,...,NFN and by the device NF1, according to the first and second variant embodiments of the invention.

[0097] Figure 5 illustrates the second embodiment variant, which is implemented by each NFn device, n=3,...,N. As indicated previously, in the illustrative example envisaged here, the NF3,...,NFN devices host instances of the same NWDAF network function for collecting and analyzing data. These devices are geographically distributed over the coverage area of ​​the NW network, each NFn device serving a service area Zn in which it implements the functionality(s) of an NWDAF network function, namely for example collecting data representative of network facts (e.g. state of a user equipment, cell in which it is located, etc.) from other network functions and / or radio nodes via the OAM entity of the network, establishing statistics and / or predictions (global and / or individual) from the collected data, etc.

[0098] As mentioned previously, the service zone Zn of the NFn device covers a number Kn of elementary zones ZEk(n), k=l,...,Kn associated with the network, Kn designating an integer greater than or equal to 1 which can vary from one NFn device to another. In the example considered here, each elementary zone ZEk(n) is a cell of the NW network.

[0099] Figure 7 illustrates an example of service areas Z3, Z4, Z5 and Z6 assigned respectively to devices NF3, NF4, NF5, NF6 hosting a network function NWDAF. In the example of Figure 7, we consider as elementary areas hexagonal cells of the NW network referenced by Cl, C2,..., and K3 is taken equal to 7, K4 equal to 5, K5 equal to 5, and K6 equal to 5. More precisely: Z3={ZE1(3)=C1, ZE2(3)=C2, ZE3(3)=C3, ZE4(3)=C5, ZE5(3)=C6, ZE6(3)=C7, ZE7(3)=C10}; Z4={ZE1(4)=C3, ZE2(4)=C4, ZE3(4)=C6, ZE4(4)=C7, ZE5(4)=C8}; Z5={ZE1(5)=C5, ZE2(5)=C6, ZE3(5)=C9, ZE4(5)=C10, ZE5(5)=C14}; and Z6={ZE1(6)=C7, ZE2(6)=C11, ZE3(6)=C12, ZE4(6)=C15, ZE5(6)=C16}.

[0100] Cell C13 is covered by devices other than NF3, NF4, NF5, NF6 devices.

[0101] As illustrated in Figure 7, the service areas of some of the devices NF3,...NFN can be defined so as to be overlapping. For the purposes of the invention, overlapping areas are areas that are not disjoint, i.e. that have a non-empty intersection (in the topological sense of the term). In other words, the same elementary area can be covered by the service areas of several devices providing the same network function. This is the case in particular for cell C6 which is covered by the three service areas Z3, Z4 and Z5 of the devices NF3, NF4 and NF5, for cell CIO which is covered by the service areas Z3 and Z5 of the devices NF3 and NF5, or for cell C7 which is covered by the service areas Z3, Z4 and Z6 of the devices NF3, NF4 and NF6, etc.

[0102] It is noted that the overlapping service areas may originally have been defined in a disjointed manner, then extended to present overlaps, for example in order to allow the execution of certain procedures within the network, such as in particular the preparatory phase which precedes a transfer procedure between two AMF functions.

[0103] According to the invention, the device NFn obtains, via its module 8A', weights (real numbers greater than or equal to 0) assigned to each of the elementary zones covered by its service zone Zn. As mentioned previously, these weights may have been assigned in different ways to the elementary zones ZEk(n), k=l,...,Kn covered by the service zone Zn. They may in particular have been assigned statically by the operator of the cellular network (and of the core network CN) and then have been configured at the level of the device NFn by the latter, for example via a message or an appropriate configuration interface, provided for this purpose, or dynamically, for example by the obtaining module 8A' itself, by executing an algorithm defined and parameterized by the network operator.Regardless of the method chosen, the weights may also change over time, for example in the event of the disappearance or appearance of an instance of the network function, temporary unavailability of this instance, a desire to balance the load, etc.

[0104] To properly assign each weight to each elementary zone, a strategy consistent with the policy that the network operator wishes to implement to select one device among several implementing a given network function is applied. This policy can take into account several factors, such as the network function implemented, the context in which the elementary zones are located (e.g. urban or rural environment) and the mobility of user equipment that may result (e.g. high or low mobility), the configuration of the service areas (e.g. shape, coverage), etc.

[0105] In the embodiment envisaged here, each weight assigned to an elementary zone for the service zone Zn of the device NFn reflects the relevance of this device (or equivalently the priority that one (e.g. the operator of the network NW) grants to it) to ensure the NWDAF network function in this elementary zone (for example in view of the preferences of the operator), taking into account the fact that this same network function can be executed by other devices serving this same elementary zone, and that the UEs (user equipment) on which the statistics and / or predictions entrusted to the NWDAF network function are likely to be carried out are likely to move. The weight w(ZEk(n)) assigned to the elementary zone ZEk(n), for k= l,...,Kn therefore takes into account here the fact that this elementary zone is covered or not by other devices NFj with j=3,...,N, j*n: in particular, each weight is expressed in the form of a percentage and the sum of the weights assigned to an elementary zone covered by several service zones is normalized (i.e. taken equal to 1 or equivalently to 100%) over all of said service zones. In addition, different weights are assigned for the same elementary zone to the different service zones associated with devices hosting the same network function and covering this elementary zone.Of course, other choices can be considered, such as assigning absolute weights that are not standardized (i.e. whose sum is not equal to 1) but expressed according to the same scale, rather than relative weights such as percentages, having a sum of weights less than 1 or different from 1, assigning real weights rather than rational ones, assigning identical weights for certain service areas when they cover the same elementary area (for example if one does not wish to give priority to one of the service areas over the other for this elementary area), etc.

[0106] Different criteria can be considered for assigning a weight to an elementary zone covered by a service area. Thus, according to an illustrative but non-limiting example, when the same elementary zone is covered by several service areas assigned to different devices hosting the same network function, to take into account the potential mobility of the UEs attached to an NFn device, the weight assigned to this elementary zone for an NFn device may depend on its distance (evaluated for example by taking as reference its center or its barycenter) relative to the center of the service area Zn of the NFn device considered or its distance relative to the limits of the service area Zn: for example, the further the elementary zone is from the center (or the barycenter) of the service area Zn or the closer it is to an edge or the border of the service area Zn,the lower the weight assigned to it for this service area compared to the service areas of the other devices covering the elementary area can be chosen, in order to reflect that the NFn device has less "priority" than the others in this elementary area.,

[0107] Figure 8 illustrates this principle in a simple way for two devices DI' and D2' hosting instances of the same network function, to which the service areas ZI' and Z2' are respectively assigned. The centers of the service areas ZI' and Z2' are noted respectively 01' and 02'. Furthermore, in this figure 8, for the sake of simplification, only the cells covered by the two devices are referenced by C1', C2', C3', C4' and C5'. Thus, in this example, in accordance with the principle mentioned above, cell C4' is assigned a greater weight for device D2' than for device DI': in fact, cell C4' is located at the edge of the service area ZI' of device DI' and while it is far from the edge of the service area Z2'. Conversely, a lower weight is assigned to cell C3' for device D2' than for device DI'.

[0108] It should be noted that it is not necessary to normalize the weights assigned to the different elementary zones of the same service area, the selection being made not within the same service area, but between several devices having overlapping service areas. Furthermore, if an elementary zone is only covered by a single service area for a given network function, in the embodiment described here, it is assigned the maximum weight (for example 100%).

[0109] In an alternative embodiment, it is possible to assign a weight, in particular a non-zero weight, only to the elementary zones covered by service zones associated with several devices hosting the same network function, and when it is desired to assign different weights to these overlapping elementary zones.

[0110] Thus, in view of the above, the weight assigned to an elementary zone for the service area Zn reflects in some way the more or less important attachment of this elementary zone to the service area Zn and therefore to the NFn device serving this service area; in other words, this reflects whether when it comes to covering this elementary zone, it is in one's interest to select the NFn device or another more relevant and more appropriate device. The weights assigned to the same elementary zone for different service areas covering this elementary zone therefore make it possible to assign different priorities to the associated devices, and therefore to guide the choice of a device among the others based on these priorities. It should be noted that conversely, if one does not wish to establish priority between two devices implementing the same network function, the same weight can be allocated to an elementary zone for the service areas of these two devices. [YES] Other factors or criteria than the distance and / or proximity to the border of the service area of ​​a device may be taken into account to assign a weight to an elementary area for a given device NFn, n=3,...,N. For example, a load distribution policy between several devices implementing the same network function on an elementary area may also be taken into account. This factor may be taken into account in particular to justify the assignment of two different weights to an elementary area covered by two separate devices and located at an equal distance from the center of the service areas served by these devices or from the border of these service areas. As mentioned above, the context of application of the invention, the strategy that the network operator wishes to adopt, the network topology, etc. may also be taken into account.

[0112] As an illustration, in the example of Figure 7, by applying the strategy mentioned above (weights assigned according to the distance to the centers or edges of the service areas), the following rational weights noted w were assigned by the network operator to the elementary zones of the service areas Z3, Z4, Z5 and Z6: for the NF3 device and the corresponding service area Z3: w(ZEl(3)=Cl)=100%, w(ZE2(3)=C2)= 100%, w(ZE3(3)=C3)=40%, w(ZE4(3)=C5)=40%, w(ZE5(3)=C6)=70%, w(ZE6(3)=C7)=20%, w(ZE7(3)=C10)=40%; for the NF4 device and the corresponding Z4 service area: w(ZEl(4)=C3)=60%, w(ZE2(4)=C4)=100%, w(ZE3(4)=C6)=20%, w(ZE4(4)=C7)=10%, w(ZE5(4)=C8)=100%; for the NF5 device and the corresponding Z5 service area: w(ZEl(5)=C5)=60%, w(ZE2(5)=C6)=10%, w(ZE3(5)=C9)=100%, w(ZE4(5)=C10)=60%, w(ZE5(5)=C14)=100%; for the NF6 device and the corresponding Z6 service area: w(ZEl(6)=C7)=70%, w(ZE2(6)=Cll)=100%, w(ZE3(6)=C12)= 100%, w(ZE4(6)=C15)= 100%, w(ZE5(6)=C16)= 100%.

[0113] It should be noted that according to this example a weight of 100% has been assigned to an elementary zone for a given device when this device is the only one to cover this elementary zone. It should be noted that it is not excluded from this fact to have two elementary zones located at the same distance from the center of a service zone covering it assigned to different weights, since we are interested here in the management of overlapping zones.

[0114] Thus, in the illustrative example of Figure 7, we favor the choice of device NF3 to cover cell C6, the choice of device NF4 to cover cell C3, the choice of device NF6 to cover cell C7, etc.

[0115] Of course, this example is given for illustrative purposes only, and other weights may be affected.

[0116] The weights thus assigned to the different elementary zones of the network covered by the service zone Zn of the NFn device are stored for example in the non-volatile memory 6 of the computer 2 hosting the NFn device. With reference to figure 5, they can thus be obtained by the module 8A' of the NFn device by consulting this memory (step E10).

[0117] Then they are provided via its supply module 8B' to the device NF1 storing the profiles of the network function instances operating in the core network CN (step E20). More specifically, in the second embodiment described here, the weights w(ZEk(n)) assigned to the different elementary zones ZEk(n) of the network covered by the service zone Zn of the device NFn are provided to the device NF1 implementing the network function NRF when recording the profile NFPROF(NFn) of the device NFn with the device NF1. This recording is based here on the Nnrf_NFManagement service offered by the NF1 device as described in the TS 23.501 document cited previously, arranged so that the NFn device can declare in its profile, in addition to its service area Zn as already provided for by the 3GPP standard as well as its various service characteristics, the weights w(ZEk(n)), k=l,...,Kn assigned to each of the Kn elementary areas (i.e.cells in the example considered here) of the network covered by the service area Zn.

[0118] We note that if all or part of the weights assigned to the elementary zones ZEk(n) of the network covered by the service area Zn of the NFn device evolve over time, the module 8B' of the NFn device can provide the weights that have evolved (or again all the weights) by updating its profile, for example by using again the Nnrf_NFManagement service offered by the NF1 device which allows such an update, arranged to include an update of the weights.

[0119] The assignment of weights to the elementary zones and steps E10 of obtaining and E20 of providing these weights are executed in a similar or identical manner by each of the devices NF3,...,NFN.

[0120] We will now describe with reference to figure 6 the supply method according to the first embodiment variant as implemented by the NF1 device.

[0121] In accordance with this first variant and following step E20 which has just been described, the device NF1 obtains, via its obtaining module 8A, for each device NFn, n=3,...,N, the weights w(ZEk(n)) assigned to the different elementary zones ZEk(n) of the network covered by the service zone Zn of the device NFn during the recording of the profile NFPROF(NFn) of the device NFn (or the updating of this profile) (step F10). The obtaining module 8A stores the profiles of the devices NFn in the non-volatile memory 6 of the computer 2 hosting the device NF1. The same applies in the event of an update.

[0122] The weights assigned to the elementary zones covered by the service areas of the devices NF3,...,NFN can thus be made available (i.e. provided) easily to the consumer network function instances of the CN network wishing to request these devices for the collection and / or analysis of data, in the same way as the other information stored in the profile of these devices. For this purpose, the consumer instances can use, for example, the Nnrf_NFDiscovery service implemented by the device NF1. A "consumer" device can in particular access the weights assigned to the elementary zones of the network covered by the service area of ​​a device NFn, n=3,...,N by sending a discovery request to the device NF1, as described in more detail below with reference to Figure 9.

[0123] Figure 9 illustrates the main steps of a selection method according to the invention implemented in a particular embodiment by a network consumer device such as the NF2 device in the example envisaged in Figure 2.

[0124] As mentioned previously, it is assumed here that the NF2 device hosts an AMF network function and wishes to access, for the needs of this network function, statistics and / or predictions, established by a NWDAF network function of the CN core network and relating to a UE referenced by 9 in figure 2, which is attached to it (in other words which is managed by it).

[0125] For this purpose, it sends via its sending module 9A a discovery request REQ to the device NF1 providing the network function NRF in the core network CN (step G 10). The discovery request REQ sent by the device NF2 aims to discover the devices of the network CN hosting a network function and here meeting two search criteria CRIT specified in the request, namely a particular type of network function (NWDAF in the example considered here) and a zone of interest ZI defined by the consumer device NF2.

[0126] Alternatively, the discovery request REQ may cover a greater or lesser number of criteria; for example, the discovery request may specify only the network function that the devices sought must implement, and / or other criteria (e.g., particular statistics or predictions, etc.).

[0127] In the example envisaged here, the area of ​​interest ZI corresponds to the area in which the UE 10 is located. It is derived here by the device NF2 from the registration area RA assigned to the UE 10. For example, the area of ​​interest ZI is the area RA assigned to the UE 10 at the time of sending the discovery request REQ; this area RA comprises one or more elementary areas of the NW network (e.g. one or more cells). In the illustrative example shown in FIG. 7, it is assumed that the area RA of the UE 10, and therefore the area of ​​interest ZI, contains only the cell C6.

[0128] With reference to Figure 6, upon receipt of the discovery request REQ by the device NF1 (step F20), the latter, via its provision module 8B, examines the profiles available to it in its non-volatile memory 6 to identify the devices of the network CN (candidate devices within the meaning of the invention) meeting the criteria CRIT (NWDAF function, ZI=RA(UE 10)) specified in the request REQ (step F30). We denote by NFCj, j=l,...,J with J being an integer greater than or equal to 1, the candidate devices thus identified. In the illustrative example envisaged in Figure 7, the candidate devices are identified by the provision module 8B among the devices NF3,...,NFN implementing the network function NWDAF and the provision module 8B determines that the candidate devices NF3, NF4 and NF5 have a service area covering the entire area of ​​interest ZI. In other words, J=3 and NFC1=NF3, NFC2=NF4 and NFC3=NF5.

[0129] The device NF1 therefore responds, via its provisioning module 8B, to the discovery request REQ of the device NF2 by identifying in its response RESP the candidate devices NFCj, j=l,...,J meeting the criteria CRIT and the service characteristics contained in the profiles NFPROF of these candidate devices and likely to interest the device NF2 (step F40). In accordance with the invention, it also includes in its response RESP the weights assigned to the elementary zones covered by the service zones of the candidate devices NFCj, j=l,...,J. Thus, in the illustrative example considered with reference to FIG. 7, it includes the weights w(ZEk(n)), k=l,...,Kn for n=3, 4 and 5.

[0130] It is noted that in the embodiment described here, the device NF1 sends to the device NF2 not only the weights assigned to the elementary zones included in the zone of interest ZI, but also the weights assigned to the elementary zones not included in this zone ZI. An example of use of these weights outside the zone of interest ZI is described in more detail later.

[0131] Alternatively, only the weights corresponding to the elementary zones covering the area of ​​interest ZI are included in the RESP response, if such an area of ​​interest has been specified in the discovery request as a CRIT criterion. This variant makes it possible to limit the size of the message sent by the NF1 device to the NF2 device; however, it requires an additional filtering effort from the NF1 device.

[0132] With reference to Figure 9, upon receipt of the RESP response by the obtaining module 9B of the NF2 device (step G20), if J>1, the NF2 device compares the weights assigned to the elementary zones covering the area of ​​interest ZI obtained for the different candidate devices NFCj, j=1,...,J. In the embodiment described here, to carry out this comparison, the NF2 device determines, via its determination module 9C, for each candidate device NFCj, j=1,...,J identified in the RESP response, a metric noted p(NFCj) from the weights assigned to the elementary zones covered by the service area of ​​this candidate device and by the area of ​​interest ZI (step G30).

[0133] It is noted that if the area of ​​interest ZI is not included in the search criteria CRIT specified in the search query, the determination module 9C chooses from the candidate devices NFCj, j=l,...J identified in the response RESP, those having a service area covering the area of ​​interest, and determines the metric p(NFCj) only for the candidate devices thus chosen.

[0134] In the embodiment described here, the metric p(NFCj) calculated by the determination module 9C for each candidate device NFCj concerned is the sum of the weights assigned to the elementary zones covered by the service area of ​​this candidate device and by the area of ​​interest ZI.

[0135] Alternatively, one can consider applying weighting factors to each weight (e.g., between 0 and 1). An example of such a weighted sum is given later.

[0136] In the illustrative example considered with reference to Figure 7 (NF3, NF4 and NF5 identified as candidate devices and area of ​​interest ZI containing cell C6), the metrics evaluated by the determination module 9C are as follows: p(NFCl=NF3)=70%; p(NFC2=NF4)=20%; p(NFC3=NF5)=10%.

[0137] The 9D selection module of the NF2 device then selects the candidate device NFCjO optimizing the metric p to implement the NWDAF network function sought by the NF2 device (step G40), in other words, in the embodiment described here, the one that maximizes the metric p (it is noted that depending on the metric p envisaged and the way in which the weights are assigned to the elementary zones, the 9D module may be led to select the candidate device minimizing the metric p to optimize it). In the illustrative example envisaged here, it is the NF3 device that is selected to implement the NWDAF function needed by the NF2 device on the zone of interest ZI={C6}.

[0138] Following this selection, the NF2 device addresses its request to the selected NFCjO device, this request indicating the statistics and / or predictions desired by the NF2 device (step G50).

[0139] It may happen that during the execution of the functionalities assigned to it, a network function instance (for example the NF3 device selected during step G50) must transfer the requests addressed to it in whole or in part to another instance implementing the same network function. This transfer from an instance described as a “source” to an instance described as a “target” or relay may be triggered for internal reasons (e.g. load balancing, gradual shutdown of the instance, etc.), or for external reasons (e.g. mobility of a user equipment for which it is responsible) signaled for example by other network functions to which it has subscribed to be informed of the corresponding events. Such a transfer requires the selection of a new network function instance (i.e. the target instance or serving as a relay in an equivalent manner).

[0140] Figure 10 represents the main steps implemented here by the previously selected NF3 device (source device) when such a situation arises, requiring a transfer to a target instance also implementing the NWDAF network function to serve as a relay for the NF3 device for all or part of the functionalities that it implements. These steps repeat, possibly with some adjustments, the steps of the selection method according to the invention which have just been described.

[0141] More specifically, it is assumed that the NF3 device detects that a transfer is necessary to another NWDAF instance of all or part of the subscriptions or requests addressed to it, and more particularly here, of the prediction and statistics requests addressed by the NF2 device in relation to the UE 10 (step H 10). As mentioned above, the detection that a transfer is necessary may be based on information reported by other network functions of the CN core network, such as in particular the notification of events to which the NF3 device has previously subscribed. For example, the NF3 device may, on the basis of the location information of the UE 10 reported to it by the NF2 device (AMF), detect that the UE 10 is moving and determine whether it is still able to provide the analysis and prediction service required by the NF2 device or whether it must transfer the corresponding subscriptions from the NF2 device to another NWDAF instance (target instance).

[0142] In the embodiment described here, following this detection, the device NF3 selects the target NWDAF instance (or equivalently the device hosting this target instance) to which to carry out the transfer if it is confirmed. For this purpose, it sends a discovery request REQ to the device NF1 (step H20) comprising at least one CRIT criterion which the searched devices must meet. In the context of a transfer procedure between two devices implementing an NWDAF network function, the discovery request includes the NWDAF type as criterion CRU. It may also optionally include an area of ​​interest defined by the device NF3, corresponding for example to the current location of the UE 10.It is assumed here for illustration purposes that the area of ​​interest ZI specified in the discovery request is the area RA of the UE 10, and more particularly the cell C7 in the example of FIG. 7, the UE 10 having moved from the cell C6 to the cell C7 after the selection of the device NF3. The sending step H20 is identical to the step G10 previously described with reference to FIG. 8.

[0143] The steps F20, F30 and F40 already described are implemented by the device NF1 upon receipt of this discovery request REQ. It is assumed here that the response RESP addressed by the device NF1 to the device NF3 in step F40 identifies the candidate devices NFCm, m= 1,...,M, M designating an integer greater than 1, and provides the device NF3 for each of these candidate devices, the weights associated with the elementary zones covered by the service zones of these candidate devices (or only those assigned to the elementary zones covered by the service zones of the candidate devices and by the zone of interest ZI specified where appropriate in the discovery request). With reference to the illustrative example shown in FIG. 7, it is assumed for example that the response RESP addressed to the device NF3 identifies the devices NF3, NF4 and NF6.

[0144] Upon receipt of this response (step H30 identical to step G20), if the number of distinct candidate devices of the NF3 device is greater than 1, the NF3 device compares the weights assigned to the elementary zones covering the area of ​​interest ZI obtained for the different candidate devices NFCm, m=l,...,M, with NFCm*NF3. More particularly, to carry out this comparison, the NF3 device determines here, via its determination module 9C, for each candidate device NFCm, m=l,...,M, with NFCm*NF3, identified in the RESP response, a metric noted p'(NFCm) from the weights assigned to the elementary zones covered by the service area of ​​this candidate device and by the area of ​​interest defined by the NF3 device (step H40).It is noted that if a single candidate device distinct from the NF3 device is identified in the response received, the determination module 9C selects this candidate device as a potential relay for the NF3 device and triggers the transfer to it of all or part of the subscriptions sent to it by the NF2 device when the need for transfer is confirmed (for example, when the NF3 device detects that the UE 10 is located in the cell C8, outside the coverage of the NF3 device).

[0145] As mentioned previously, if the area of ​​interest ZI is not included in the search criteria CRIT specified in the search request, the determination module 9C chooses from among the candidate devices NFCm, m= l,...M identified in the response RESP those having a service area covering the entire area of ​​interest, and only determines the metric p'(NFCm) for the candidate devices thus chosen.

[0146] In the embodiment described here, the metric p'(NFCm) calculated by the module 9C for determining the device NF3 for each candidate device NFCm concerned other than NF3 is the weighted sum of the weights assigned to the elementary zones covered by the service area of ​​this candidate device and by the area of ​​interest. In the example envisaged here of a handover required due to the mobility of the UE 10, the weighting factors applied to the weights assigned to each elementary zone are representative of the probability of presence of the UE 10 in this elementary zone at a certain time horizon (for example in the next 10 minutes). In other words, the device NF3 takes into account a prediction of mobility of the UE 10 to decide the candidate device to which to carry out the handover if it is confirmed.Such presence probabilities can be determined for example by the NF3 device from the data it collects for the NF2 device (we already note that they can be part of the statistics / predictions requested by the NF2 device from the NF3 device). Alternatively, it can obtain these probabilities from other network functions of the CN core network.

[0147] It should be noted that other weighting factors than probabilities of presence of the UE 10 may be applied in the weighted sum to the weights of the elementary zones, or to calculate the metric p'(NFCm) associated with each candidate device, in particular if the transfer is envisaged for a reason other than the mobility of the UE 10. The weighting factors applied may be chosen in connection or not with the reason for the transfer. For example, it is possible to apply, as in step G30 described previously, unit weighting factors to each weight considered in the metric. According to another example, it is possible to envisage using as weighting factors other information contained in the profiles of the candidate devices stored with the device NF1, such as for example the charge levels of the candidate devices.

[0148] For illustration purposes, it is assumed that the NF3 device determines the following probabilities noted Prob of presence of the UE 10 in the elementary zones covered by the candidate devices identified in the RESP response (NF4 and NF6 in the illustrative example considered here): Prob(C3)=0%, Prob(C4)=0%, Prob(C6)=0%, Prob(C7)=30%, Prob(C8)=50%, Prob(Cll)=10%, Prob(C12)=10%, Prob(C15)=0%, Prob(C16)=0%.

[0149] In this example, the sum of the probabilities over all the elementary areas covered by the candidate devices is normalized. Note, however, that such normalization is not mandatory. It may depend in particular on how is defines the probability of the UE being present in a given elementary area. For example, if this probability is defined as the probability that the UE is found at least once in this elementary area in a given time horizon, the sum of the probabilities obtained may be greater than 1. On the other hand, if we consider the probability of the presence of a UE in an elementary area at a given time, the sum of the probabilities is normalized by definition.

[0150] This results in the following metrics: p'(NFCl = NF4)=w(ZEl(4)=C3).Prob(C3)+w(ZE2(4)=C4).Prob(C4) +w(ZE3(4)=C6).Prob(C6)+w(ZE4(4)=C7).Prob(C7) +w(ZE5(4)=C8).Prob(C8) = 10%x30%+100%x50% = 53%; and: p'(NFC2=NF6)= w(ZEl(6)=C7).Prob(C7)+w(ZE2(6)=Cll).Prob(Cll) +w(ZE3(6)=C12).Prob(C12)+w(ZE4(6)=C15).Prob(C15) +w(ZE5(6)=C16).Prob(C16) = 70%x30%+ 10%xl00%+ 10%xl00% = 41%.

[0151] We note that the sum of the metrics p' is not equal to 100% here because the NF3 device also covers the area of ​​interest but is not taken into account in the calculation of the metrics since we are interested in a transfer from this device (the metric p' calculated for the NF3 device is actually equal to 6% so that the sum on the NF3, NF4 and NF6 devices is indeed equal to 100%).

[0152] The NF3 device selection module 9D then selects the candidate device NFCmO optimizing the metric p' as a relay potential to perform the predictions / statistics required by the NF2 device (step H50), in other words, in the embodiment described here, the one that maximizes the metric p'. In the illustrative example envisaged here, it is the NF4 device that is selected as a relay potential, in other words as the target device to which to trigger the transfer.

[0153] Following this selection, if the handover is confirmed (for example, the NF3 device detects that the UE 10 leaves its service area and enters the cell C8, in accordance with the predictions made), the NF3 device transfers, via its transfer module 9E, the subscriptions addressed to it by the NF2 device to the NF4 device so that it takes charge of these subscriptions (step H60). The NF4 device then takes charge of the subscriptions, collects the network data and carries out the corresponding predictions / statistical analyses at the end of the handover.

[0154] It is noted that the handover to the NF4 device may ultimately be canceled for various reasons. For example, if the mobility of the UE 10 was the reason for such a handover and the UE 10 stops moving and remains in cell C7, such a handover may prove unnecessary and be canceled by the NF3 device. Similarly, if the UE 10 moves to cells C11 or C12, a handover to the NF4 device is no longer relevant. Depending on the context, if a handover is still necessary, the NF3 device may again request the NRF1 device to identify another relay device for this handover.

[0155] Furthermore, as mentioned previously, it is possible, upstream of the transfer, to trigger a transfer preparation phase during which the candidate device identified as a relay (for example, the NF4 device in the illustrative example envisaged previously) for the source device begins to collect data so as to be effective from the transfer to carry out the statistical analyses / predictions corresponding to the subscriptions transferred to it. The invention advantageously makes it possible to determine when to trigger this preparation phase, by exploiting the weights provided by the NF1 device.

[0156] More particularly, different criteria can be examined by the transfer module 9E of the device NF3 to determine whether or not it triggers the preparation phase for the transfer to the device NF4. For example, the transfer module 9E of the device NF3 triggers the preparation phase when it detects that the UE 10 attached to it enters an elementary zone which is covered by its service zone Z3 (and by the service zone of the device NF4 selected for the transfer) and to which is assigned, for the service zone Z3, a weight lower than a given threshold. To avoid triggering the preparation phase in an untimely manner, a threshold strictly lower than 50% is chosen here, for example 30%. In the example of FIG. 7, the preparation phase is thus typically triggered when the UE 10 enters the cell C7 of the service zone Z3 of the device NF3 which is assigned a weight of 20%, lower than the threshold of 30%.We can also consider a hysteresis and only trigger the preparation phase when, on the one hand, the weight assigned to the elementary zone into which the UE 10 enters is lower than a given threshold and, on the other hand, the difference between said threshold and the weight assigned to the elementary zone into which the UE 10 enters exceeds a certain value.

[0157] According to another example, the handover module 9E of the NF3 device triggers the preparation phase when it detects that the UE 10 enters an elementary area which is covered by its service area Z3 (and by the service area of ​​the NF4 device selected for the handover) and to which is assigned, for the service area Z3, a weight lower than the weight assigned to this same elementary area for another device implementing the network function NWDAF (i.e. the same network function as the source NF3 device). In the example of Figure 7, this is for example the case when the UE 10 enters cells C3, C5, C7 or CIO, only C3 and C7 being however covered by the NF4 device and relevant for a handover to the NF4 device.

[0158] If the criterion examined by the transfer module 9E is verified, the latter triggers the phase of preparing the transfer to the target device selected during step H50 in a manner known per se (device NF4 in the illustrative example envisaged), as described in particular in document TS 23.288 in paragraph 6.1B2.2.

[0159] The invention has just been described with reference to a 5G core network, and to NWDAF, AMF and NRF network functions. However, the invention can be applied in other contexts, to other networks as well as to other network functions as soon as a selection is necessary between several devices implementing the same network function and having overlapping service areas.

Claims

Demands

1. A method for providing information relating to a first device (NF3,...,NFN) of a communication network, said first device hosting a network function implementing at least one functionality in said network in a service area covering an integer number, greater than one, of so-called elementary areas, each elementary area corresponding to a cell of said network or to a location area defined for said network, said method comprising: a step (E10,F10) of obtaining, for at least one elementary area covered by said service area of ​​the first device, a weight assigned to that elementary area, said weight being a real number greater than or equal to 0; and a step (E20,F40) of providing to a second device (NF1,NF2,NF3) of the network all or part of said weights obtained during the obtaining step.

2. A supply method according to claim 1 wherein said second device (NF1) is configured to manage devices hosting network functions and all or part of said weights obtained are supplied to the second device during a registration (E20) or a profile update of the first device with the second device.

3. Supply method according to claim 1 or 2 implemented by the first device, wherein said first device (NF3,...,NFN) hosts a network function for collecting and analyzing network data.

4. Supply method according to claim 1 wherein the weights obtained assigned to the elementary areas covered by said service area are obtained (F10) during a recording of a profile of the first device and all or part of said weights obtained are supplied in response to a discovery request (REQ) of network devices hosting a network function and meeting at least one given search criterion (CRIT), said discovery request originating from the second device (NF2,NF3) and said first device meeting said at least one given search criterion.

5. A supply method according to any one of claims 1 to 4 wherein the weight assigned to said elementary zone depends on a distance from this elementary zone to a center of the service zone and / or its distance from a boundary of said service zone.

6. A supply method according to any one of claims 1 to 5, wherein, when said elementary area is covered by the service area of ​​the first device and at least one other service area of ​​at least one third device in the network hosting the same network function as said first device: a different weight is assigned to said elementary area for the service area of ​​the first device and for said at least one other service area of ​​said at least one third device; and / or a sum of the weights assigned to said elementary zone for said service zone of the first device and for said at least one other service zone of said at least one third device is non-zero and less than or equal to 1.

7. A supply method according to any one of claims 1 to 6 comprising: a step of updating at least one weight assigned to an elementary zone covered by said service zone; and a step of supplying said at least one updated weight to the second device.

8. Method of selecting by a device (NF2,NF3) of a communication network, called fourth device, comprising: a step (G10,H20) of sending, to a device (NF1) of the network called fifth device, a discovery request (REQ) of devices of the network hosting a network function and meeting at least one given search criterion;a step (G20,H30) of obtaining a response to said discovery query identifying at least one device of the said candidate network hosting a network function and meeting said at least one given search criterion, said response comprising for each candidate device having a service area covering an area of ​​interest defined by the fourth device, said service area covering an integer number, greater than one, of said elementary areas, each elementary area corresponding to a cell of said network or to a location area defined for said network, a weight assigned to each elementary area covered by said service area and said area of ​​interest, said weight being a real number greater than or equal to 0;and a step (G40,H50) of selecting said candidate device to implement at least one functionality of the network function it hosts by comparing the weights assigned to the elementary areas covered by said area of ​​interest obtained for each candidate device identified in the response.

9. Selection method according to claim 8 wherein the selection step includes a determination (G30,H40), for each candidate device of the network identified in the response, of a metric from the weights obtained assigned to the elementary areas covered by the service area of ​​this candidate device and by the area of ​​interest, the selected candidate device being the one that optimizes said metric among the candidate devices identified in the response.

10. Selection method according to claim 9 wherein in the metric determined for said candidate device is a weighted sum of the weights assigned to the elementary areas covered by the service area of ​​said candidate device and by the area of ​​interest.

11. Selection method according to claim 10 wherein, in the weighted sum, each weight assigned to an elementary zone is weighted by a probability of presence of a user equipment managed by the fourth device in that elementary zone.

12. A selection method according to any one of claims 8 to 11 wherein the fourth device (NF3) and said selected candidate device (NF4) host the same network function, and said selected candidate device (NF4) is used as a relay for the fourth device to implement at least one functionality of said network function.

13. Selection method according to claim 12 further comprising, when the fourth device detects an input from a user equipment (10) that it manages in an elementary area covered by its service area and having a weight assigned to the fourth device less than a given threshold or less than a weight assigned to said elementary area for said candidate device identified in the response to the discovery request, triggering a preparation phase for using the selected candidate device as a relay for the fourth device.

14. A method according to any one of claims 1 to 13 wherein said network (NW) is a cellular network and each elementary zone comprises at least one cell of the cellular network.

15. A so-called supply entity (NF1,NF3,...,NFN) of a communication network, configured to supply information relating to a first device of said network, said first device hosting a network function implementing at least one functionality in said network in a service area covering an integer number greater than one of so-called elementary areas, each elementary area corresponding to a cell of said network or to a location area defined for said network, said supply entity comprising: a retrieval module (8A,8A'), configured to obtain, for at least one elementary area covered by the service area of ​​the first device, a weight assigned to that elementary area, said weight being a real number greater than or equal to 0; and a supply module (8B,8B'), configured to supply to a second device of the network, all or part of the weights obtained by the retrieval module.

16. A so-called selection entity (NF2, NF3) of a communication network comprising: a sending module (9A), configured to send a network device a request to discover network devices hosting a network function and meeting at least one given search criterion; a retrieval module (9B), configured to obtain a response to said discovery request identifying at least one so-called candidate network device hosting a network function and meeting said at least one given search criterion, said response comprising, for each candidate device having a service area covering an area of ​​interest defined by the selection entity, said service area covering an integer number, greater than one, of so-called elementary areas, each elementary area corresponding to a cell of said network or to a location area defined for said network, a weight assigned to each elementary area covered by said service area and said area of ​​interest, said weight being a real number greater than or equal to 0; and a selection module (9D), configured to select said candidate device to implement at least one feature of the network function it hosts, by comparing the weights assigned to the elementary areas covered by said area of ​​interest obtained for each candidate device identified in the response.

17. System (1) in a communication network (CN,NW) comprising: at least one device (NF3,...,NFN) for collecting and analyzing network data comprising a first supplying entity according to claim 15; a device (NF1) for managing profiles of a plurality of devices hosting network functions of the network, comprising a second supplying entity according to claim 15; and a device (NF2,NF3) hosting a network function of the network and comprising a selection entity according to claim 16.

18. System (1) according to claim 17 in which the device (NF3) hosting a network function of the network is said to be a collection and analysis device.

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