Patent Description:
In the 3GPP standard TS23. <NUM> related to the fifth generation (<NUM>) core network, a network slice to be connected to a user terminal is determined on the basis of information managed in a core network. Here, the information managed in the core network is, for example, subscribed single network slice selection assistance information (S-NSSAI) managed in a unified data management (UDM). On the basis of the S-NSSAI, a single network slice is identified. The subscribed S-NSSAI is S-NSSAI-based subscriber information, and indicates a network slice to which user equipment (UE) is subscribed for use in a public land mobile network (PLMN). The S-NSSAI includes a slice/service type (SST) and a slice differentiator (SD). The SST refers to network slice behaviour expected in terms of functions and services. The SD is optional information that complements a slice/service type to discriminate among a plurality of network slices within the same SST. For such a network slice, for example, a mobile communication system has been proposed in which a network slice to be allocated to a service is dynamically changed for each user in accordance with a status of the user (see, for example, Patent Document <NUM>).

In the conventional technique described above, a network slice is switched on the basis of a service type in use or a context in use of a service at a user terminal, and a core network determines switching to the network slice on the basis of a request from the user terminal. However, a service provider that provides the service constructs and operates the network slice to which various resources are allocated in accordance with the estimation of the service demand, whereas, due to physical resources and cost constraints, it is not always that the service provider can provide uniform service quality to all users. In addition, the level of service quality required by the users is generally different for each user, and thus it is necessary to determine the request of such a user from the position of the service provider.

The present technology has been made in view of such a situation, and an object of the present technology is to issue, from a service server of a service provider, an instruction for switching regarding a network slice to be applied to a user terminal.

The present technology has been made to solve the above issues. There are provided a network-slice control server, a service server and corresponding control methods according to the appended claims. In the following, the invention is best understood in view of <FIG>. The remaining embodiments, aspects and examples disclosed below are included for illustrative purposes and for facilitating the understanding of the invention.

Hereinafter, modes for carrying out the present technology (hereinafter, referred to as embodiments) will be described. The description will be given in the following order.

<FIG> illustrates an exemplary overall configuration of a wireless communication system according to an embodiment of the present technology.

The wireless communication system includes a service server <NUM>, a mobile network <NUM>, and a user terminal <NUM>.

The user terminal <NUM> is a user terminal that performs wireless communication in the wireless communication system. Note that the user terminal <NUM> is also referred to as, for example, user equipment (UE), or a user device.

The service server <NUM> is a server managed by a service provider that provides services. The service server <NUM> may be a server located in a data network (DN) outside the mobile network <NUM> (for example, a 3GPP system). The service server <NUM> may be operated by an entity (for example, a third party) different from an operator that provides the mobile network <NUM> (namely, a mobile network operator (MNO)). The service provider supplies its own service to the user terminal <NUM> with the service server <NUM>. In addition, the service server <NUM> performs processing such as user registration necessary for providing a service.

The mobile network <NUM> provides a wireless communication network and a core network between the user terminal <NUM> and the service server <NUM>. The mobile network <NUM> may be, for example, a fifth generation cellular network (<NUM> core network) defined by 3GPP and a wireless access network (for example, next generation radio access network (NG-RAN)).

<FIG> illustrates an exemplary configuration of the mobile network <NUM> according to the embodiment of the present technology.

The mobile network <NUM> includes an access and mobility management function (AMF) <NUM> and a unified data management (UDM) <NUM> as components of the <NUM> core network. Further, the mobile network <NUM> includes a radio access network (RAN) <NUM> as a component. The RAN <NUM> provides a network connection to the user terminal <NUM>, and includes one or more base stations (for example, gNodeB (gNB), eNodeB (eNB), new generation eNB (ng-eNB), and enhanced gNB (en-gNB). The AMF <NUM> performs access control and mobility management. The UDM <NUM> is for managing subscriber information (contract information) of the user. The RAN <NUM>, the AMF <NUM>, and the UDM <NUM> conform to those disclosed in the 3GPP specification. In addition, at least one of the RAN <NUM>, the AMF <NUM>, or the UDM <NUM> may be included in part of a network function (NF) provided in the 3GPP specification. Note that the RAN <NUM>, the AMF <NUM>, and the UDM <NUM> may each serve as dedicated hardware, or may each serve as software to be executed on a general-purpose server by server virtualization or container-based virtualization.

Further, the mobile network <NUM> provides a network slice to the user terminal <NUM>. The network slice is a logical network that can provide a specific network capability and a specific network characteristic, and includes one or more network slice instances. Such a network slice instance refers to a set of one or more network functions (NFs) and one or more resources (for example, computing resources, storage resources, and networking resources) that form a network slice to be located. In this embodiment, such network slices are roughly divided into a general-service network slice <NUM> and a specific-service network slice <NUM>. The specific-service network slice <NUM> is a network slice optimized for a specific service provided by the service server <NUM>. The general-service network slice <NUM> is a network slice different from the specific-service network slice <NUM>. In the 3GPP standard TS23. <NUM>, one of the network slices of an operator under contract with a subscriber is provided as a general-service network slice <NUM>. In contrast, in this embodiment, one of such specific-service network slices <NUM> separately secured by the service provider is allocated to the user. Note that a specific-service network slice and a general-service network slice may be distinguished due to difference in a slice differentiator (SD) in single network slice selection assistance information (S-NSSAI) for identification of these network slices. In other words, on the basis of the SD in the S-NSSAI, a network slice may be identified whether a specific-service network slice or a general-service network slice. The general-service network slice may be or include a network slice identified on the basis of default S-NSSAI.

As described above, each of the network slices may include one or more network slice instances. The one or more network slice instances may include fifth generation core (5GC) nodes such as a user plane function (UPF) <NUM> and a session management function (SMF) <NUM>. The UPF <NUM> and an UPF <NUM> each provide a user-data forwarding function. The SMF <NUM> and an SMF <NUM> are control planes for the UPF <NUM> and the UPF <NUM>.

Note that at least a specific-service network slice <NUM> among the network slices has a function of disclosing the usage of a computational or network resource (for example, computing resource, storage resource, or networking resource) of the software included in this specific-service network slice <NUM> and the execution environment thereof. In such disclosure, the network slice uses an existing monitoring or management protocol such as a simple network management protocol (SNMP) to disclose the usage of the resource to another component such as an exposure server <NUM>.

The mobile network <NUM> further includes the exposure server <NUM> (for example, network exposure function (NEF)). The NEF may be included as one function of the above AF. The exposure server <NUM> monitors the usage of the resource of at least the specific-service network slice <NUM> among the network slices. For example, the exposure server <NUM> communicates with the service server <NUM> outside the mobile network <NUM> (for example, in the DN), through a northbound application programming interface (northbound API) <NUM>, to perform various interactions. That is, the exposure server <NUM> performs interactions with the service server <NUM> outside the <NUM> core network (for example, in the DN) through the northbound API <NUM>.

<FIG> illustrates an exemplary configuration of the exposure server <NUM> according to the embodiment of the present technology.

The exposure server <NUM> includes a network-slice monitoring unit <NUM>, a subscriber-information change unit <NUM>, and a communication unit <NUM>. Note that the exposure server <NUM> is an exemplary network-slice control server described in the claims.

The network-slice monitoring unit <NUM> monitors the usage of the resource of at least the specific-service network slice <NUM> among the network slices and notifies the service server <NUM> of the monitoring result.

The subscriber-information change unit <NUM> changes subscriber information such that the user terminal <NUM> to which the service server <NUM> has issued the instruction can establish connection to the specific-service network slice <NUM>.

The communication unit <NUM> communicates with the service server <NUM> and another component included in the mobile network <NUM>.

Note that an example in which the exposure server <NUM> includes the network-slice monitoring unit <NUM> has been given here; however, this is merely an example, and thus the network-slice monitoring unit <NUM> may be provided separately from the exposure server <NUM>. Therefore, for example, an orchestrator such as an open network automation platform (ONAP), a European Telecommunications Standards Institute (ETSI) management and orchestration (MANO), or an ETSI multi access computing (ETSI MEC) may play this role.

<FIG> illustrates an exemplary configuration of the user terminal <NUM> according to the embodiment of the present technology.

The user terminal <NUM> includes a service contract unit <NUM>, a network-slice designation unit <NUM>, a communication-channel setting unit <NUM>, and a wireless communication unit <NUM>.

The wireless communication unit <NUM> performs wireless communication through the mobile network <NUM>.

The service contract unit <NUM> notifies, through the wireless communication unit <NUM>, the service server <NUM> of information regarding user registration for each service and a series of information regarding the level of requested service quality.

The network-slice designation unit <NUM> receives, from the service server <NUM>, identification information for designating a single network slice from the specific-service network slices <NUM> and notifies the communication-channel setting unit <NUM> of the identification information. The identification information for designating the network slice may be S-NSSAI managed in the UDM <NUM>, or may be an SD therein.

The communication-channel setting unit <NUM> instructs the wireless communication unit <NUM> to open a communication channel for a service, on the basis of the notification from the network-slice designation unit <NUM>.

<FIG> illustrates an exemplary configuration of the service server <NUM> according to the embodiment of the present technology.

The service server <NUM> includes a service management unit <NUM>, a resource monitoring unit <NUM>, a network-slice selection unit <NUM>, a storage unit <NUM>, and a communication unit <NUM>.

The communication unit <NUM> communicates with the user terminal <NUM> or the exposure server <NUM> through the mobile network <NUM>.

The service management unit <NUM> performs processing regarding user registration, and further acquires, from the user terminal <NUM>, an identifier and a series of information regarding the level of requested service quality of the user terminal <NUM>.

The resource monitoring unit <NUM> receives, from the exposure server <NUM>, the usage of the computational or network resource of the software included in the specific-service network slice <NUM> and the execution environment thereof.

The network-slice selection unit <NUM> selects a specific-service network slice <NUM> on the basis of service contract information stored in the storage unit <NUM>. The network-slice selection unit <NUM> issues, to the exposure server <NUM>, an instruction such that the user terminal <NUM> can establish connection to the specific-service network slice <NUM>. Further, the network-slice selection unit <NUM> transmits identification information of the specific-service network slice <NUM> to the user terminal <NUM>.

The storage unit <NUM> stores, for example, an identifier (for example, S-NSSAI or SD) of the specific-service network slice <NUM>, the identifier (for example, <NUM>-globally unique temporary UE identity (<NUM>-GUTI), <NUM>-temporary mobile subscriber identity (<NUM>-TMSI), or subscription concealed identifier (SUCI)) of the user terminal <NUM>, and the level of requested service quality thereof.

<FIG> is a sequence diagram illustrating a flow of operation of a wireless communication system according to a first embodiment of the present technology.

Initially, the user terminal <NUM> is wirelessly communicable through the general-service network slice <NUM> of the mobile network <NUM> (step S811). More specifically, the user terminal <NUM> transmits and receives one or more pieces of S-NSSAI (for example, requested NSSSAI, allowed NSSAI, configured NSSAI) to and from the AMF, so that a network slice that the mobile network <NUM> provides is determined. Prior to start of using a service, the user terminal <NUM> transmits, to the service server <NUM>, information necessary for using the service, the identifier of the user terminal <NUM>, and the level of requested service quality (step S812).

Here, as the information necessary for using the service, for example, assumed is personal information such as an account name, a password, and an address of the user. The identifier of the user terminal <NUM> is information associated with a subscriber identity module (SIM), and examples of the identifier of the user terminal <NUM> include a telephone number, an international mobile subscriber identity (IMSI), and a generic public subscription identifier (GPSI). Further or alternatively, the identifier of the user terminal <NUM> may be <NUM>-GUTI, <NUM>-TMSI, or SUCI.

In addition, the level of requested service quality corresponds to a service level agreement (SLA), and assumed are options such as a best effort type in which the service quality is likely to fluctuate due to susceptibility from other service users or a band guarantee type (quality guarantee type) that is insusceptible. Further, more options can be set on the basis of insusceptibility from the other service users. Note that as a method for encoding an option, for example, considered is encoding in which integer values are used and "<NUM>" is set to the best effort type and "<NUM>" is set to the bandwidth guarantee type.

The user terminal <NUM> notifies the service server <NUM> of these pieces of information in step S812 using a secure protocol such as hypertext transfer protocol secure (HTTPS). Note that a series of these pieces of communication is performed through the general-service network slice <NUM>.

Next, the service server <NUM> selects a network slice to be provided to the user terminal <NUM>. For this purpose, the service server <NUM> designates the identifier (for example, S-NSSAI) of the specific-service network slice <NUM>, and requests the exposure server <NUM> for the usage of the computational resource (for example, computing resource) or network resource (for example, networking resource) of the software included in the corresponding network slice and the execution environment thereof (step S813).

After receiving the request from the service server <NUM>, the exposure server <NUM> measures the state of the specific-service network slice <NUM> (step S814). Specifically, the usage (usage status) of each of a processor (central processing unit: CPU), a memory, and a network of a virtual machine or a container that executes one or more network slice instances (alternatively, the UPF <NUM> and the SMF <NUM> corresponding thereto) included in the corresponding network slice is measured by utilizing an existing monitoring technique such as simple network management protocol (SNMP), NetFlow, or Zabbix.

After completing the measurement, the exposure server <NUM> notifies the service server <NUM> of the measurement result (step S815). Note that this measurement result is returned to the service server <NUM> through, for example, a hypertext transfer protocol (HTTP)-based representational state transfer (REST) API.

The service server <NUM> determines whether or not the user terminal <NUM> can establish connection to the specific-service network slice <NUM> (step S821). A specific example of the algorithm for this determination will be described later.

The service server <NUM> allows the user terminal <NUM> to be connected to the specific-service network slice <NUM>, and disconnects, from the specific-service network slice <NUM>, a user terminal <NUM> to be disconnected that is designated in step S821. For this purpose, the service server <NUM> updates subscriber information of the user terminal <NUM> to be connected and the user terminal <NUM> to be disconnected (step S832). Specifically, first, the service server <NUM> instructs the exposure server <NUM> to change, to the S-NSSAI of the specific-service network slice <NUM>, the S-NSSAI of the user terminal <NUM> to be connected, and to change, to a default value before change, the S-NSSAI of the user terminal <NUM> to be disconnected.

Note that the exposure server <NUM> corresponds to, for example, a network exposure function (NEF) defined by 3GPP. At this time, the service server <NUM> can achieve the instruction for changing, by including, in the argument of the update request (Nnef_ParameterProvision_Update), at least the respective identifiers of the user terminal <NUM> to be connected and the user terminal <NUM> to be disconnected and information regarding an identifier of the network slice determined in step S814. Here, as each identifier of the user terminal <NUM> to be connected and the user terminal <NUM> to be disconnected, for example, assumed is a telephone number, IMSI, GPSI, <NUM>-GUTI, <NUM>-TMSI, or SUCI. In addition, as the identifier of the network slice, for example, S-NSSAI, or a data network name (DNN) is assumed.

The exposure server <NUM> issues an instruction for updating the subscriber information managed in the UDM <NUM> using the information received from the service server <NUM> (step S833). The UDM <NUM> transmits the instruction to another related component of the mobile network <NUM>, so that the UDM <NUM> gives, to the user terminal <NUM> to be connected, the authority to establish connection to the specific-service network slice <NUM>. Further, as a result, the UDM <NUM> takes away, from the user terminal <NUM> to be disconnected, the authority to establish connection to the specific-service network slice <NUM>. A series of these pieces of processing is as defined by 3GPP. Finally, the service server <NUM> receives a notification of the completion through the exposure server <NUM> (step S834).

The user terminal <NUM> receives a notification of the update of the subscriber information (for example, subscribed S-NSSAI(s)) through the AMF <NUM> of the mobile network <NUM> (step S835). As a result, the user terminal <NUM> can establish connection to the mobile network <NUM> through the AMF <NUM>. However, this alone cannot specify the network slice to be connected. Thus, the service server <NUM> transmits the identifier (for example, S-NSSAI) of the network slice to be connected and information for identifying the application used in the network slice, to the user terminal <NUM> at the application level (step S836). As a result, the user terminal <NUM> can establish connection to the network slice at the application level.

The user terminal <NUM> connects to the network slice designated by the service server <NUM> and communicates with the service server <NUM> through the network slice (step S837).

<FIG> is a flowchart illustrating an exemplary processing procedure of the determination of connectability to the network slice by the service server <NUM> (step S821) according to the first embodiment of the present technology.

First, on the basis of the usage of the resource acquired in step S815, the service server <NUM> calculates whether or not the user terminal <NUM> to be connected can be accommodated (step S911).

In this algorithm, it is assumed that a predetermined certain amount of a resource is consumed due to the accommodation of the user terminal <NUM> to be connected. That is, it is assumed that the following expression is satisfied.

Here, R+i,j represents the usage of the computational or network resource j of the component i after the user terminal <NUM> to be connected establishes connection to the network slice. As the component i, for example, the UPF <NUM>, the SMF <NUM>, or a transport, is assumed. In addition, as the resource j, for example, the processor, the memory, or the bandwidth of the network is assumed. Furthermore, Ri,j represents the usage of the computational or network resource j of the component i before the user terminal <NUM> to be connected establishes connection to the network slice. Di,j represents the resource consumption of the computational or network resource j of the component i in a case where the user terminal <NUM> to be connected has established connection to the network slice. That is, the occurrence of a bottleneck is determined in consideration of for example, the usage rate of the CPU and the usage rate of the memory and the ratio of the amount of traffic transfer in the network interface of the virtual machine in the virtualized network, as the state of the network slice.

In additional accommodation of another user terminal <NUM> to be connected, the service server <NUM> determines whether or not an entity as the bottleneck is present (step S912). Note that the bottleneck refers to the usage of the resource more than the upper limit. That is, it is determined whether the component i satisfying the following condition is present.

In a case where no bottleneck occurs (step S912: No), it is determined that the user terminal <NUM> to be connected is connectable to the network slice (step S919).

Otherwise, in a case where the bottleneck occurs (step S912: Yes), the user terminal lower in requested service quality than the user terminal <NUM> to be connected is selected as the user terminal <NUM> to be disconnected (step S913), and similarly calculated is whether or not the bottleneck is eliminated in a case where the user terminal <NUM> to be disconnected is removed from the network slice (step S916). These pieces of processing are repeated until the bottleneck is eliminated (L901). When the bottleneck is eliminated, it is determined that the user terminal <NUM> to be connected is connectable to the network slice and all of such user terminals <NUM> to be disconnected are not connectable to the network slice (step S918).

As described above, according to the first embodiment of the present technology, the user terminal <NUM> can establish connection to the specific-service network slice <NUM> on the basis of the instruction for switching issued from the service server <NUM>. That is, the service provider can switch to a network slice that the user connects, between the network slices provided by the service provider.

Note that, in the first embodiment, an example of establishing connection to the specific-service network slice <NUM> has been given; however, the user terminal <NUM> may establish connection to the general-service network slice <NUM> on the basis of an instruction for switching issued from the service server <NUM>.

In the first embodiment described above, it is assumed that there is no change of the level of requested service quality of a user terminal <NUM> to be disconnected. Therefore, in a case where a new user terminal higher in the level of requested service quality is added, the user terminal to be disconnected is likely to be unilaterally disconnected from the specific-service network slice <NUM> in connection so far. Therefore, in a second embodiment, an example of giving an opportunity to update the level of requested service quality to a user terminal <NUM> to be disconnected will be given.

Note that the configuration of a wireless communication system is basically similar to that of the first embodiment described above. In the second embodiment, in a user terminal <NUM>, a service contract unit <NUM> further performs processing for updating the level of requested service quality. In addition, in a service server <NUM>, a service management unit <NUM> further performs processing for updating the level of requested service quality.

<FIG> is a sequence diagram illustrating a flow of operation of the wireless communication system according to the second embodiment of the present technology.

In the second embodiment, the processing in steps S821 to S823 described below is performed. Note that the other processing is similar to that of the first embodiment described above, and thus detailed description thereof will be omitted.

On the basis of the usage of the resource acquired in step S815, the service server <NUM> calculates whether or not the user terminal <NUM> to be connected can be accommodated, following a procedure similar to that of the first embodiment described above (step S821). Due to the calculation, in a case where it is determined that a bottleneck occurs, an inquiry as to whether the level of requested service quality is to be upgraded is made to a user terminal <NUM> to be disconnected (step S822). In response to the inquiry, the user terminal <NUM> to be disconnected transmits a reply indicating that the upgrade is permitted or the upgrade is rejected to the service server <NUM> (step S823). In other words, an opportunity to update the level of requested service quality is given to the user terminal <NUM> to be disconnected.

<FIG> is a flowchart illustrating an exemplary processing procedure of the determination of connectability to a network slice by the service server <NUM> (step S821) according to the second embodiment of the present technology.

On the basis of the usage of the resource acquired in step S815, the service server <NUM> calculates whether or not the user terminal <NUM> to be connected can be accommodated, following the procedure similar to that of the first embodiment described above (step S911).

Otherwise, in a case where the bottleneck occurs (step S912: Yes), the user terminal <NUM> to be disconnected is selected (step S913), and an inquiry as to whether or not the level of requested service quality is to be upgraded is made to the user terminal <NUM> to be disconnected (step S914). In a case where the user terminal <NUM> to be disconnected upgrades the level of requested service quality (step S915: Yes), the user terminal is no longer to be disconnected, a different user terminal <NUM> to be disconnected is selected, and the processing in and after step S913 is repeated.

In a case where the user terminal <NUM> to be disconnected does not upgrade the level of requested service quality (step S915: No), similarly calculated is whether or not the bottleneck is eliminated in a case where the user terminal is removed from the specific-service network slice <NUM> (step S916).

These pieces of processing are repeated until the bottleneck is eliminated (L901). When the bottleneck is eliminated, it is determined that the user terminal <NUM> to be connected is connectable to the network slice and all of such user terminals <NUM> to be disconnected are not connectable to the network slice (step S918).

As described above, according to the second embodiment of the present technology, an opportunity to update the level of requested service quality is given to a user terminal <NUM> to be disconnected, resulting in suppression of unintended disconnection accompanying connection of the different user terminal <NUM>.

Note that the above embodiments are examples for embodying the present technology, and thus the matters in the embodiments and the specified matters of the invention in the claims have a correspondence relationship. Similarly, the specified matters of the invention in the claims and the matters having the same names in the embodiments of the present technology have a correspondence relationship. The present technology, however, is not limited to the embodiments, and thus can be embodied by making various modifications to the embodiments without departing from the gist thereof.

Claim 1:
A network-slice control server (<NUM>) comprising:
circuitry configured to
receive from a service server (<NUM>) a request for usage of a computational resource or network resource of software included in a corresponding specific-service network slice,
measure a usage of the specific-service network slice (<NUM>), the usage being the usage status of each of a processor, a memory, and a network of a virtual machine or a container that executes one or more network slice instances included in the corresponding specific-service network slice (<NUM>),
notify the service server (<NUM>) of a measurement result of the usage status,
receive from the service server (<NUM>) an instruction to change a S-NSSAI of the user terminal to be connected to a S-NSSAI of the specific-service network slice,
instruct an unified data management, UDM, (<NUM>) to update subscriber information managed in the UDM (<NUM>) using the information received from the service server (<NUM>) in the instruction to change, and
notify the service server (<NUM>) of completion of the update,
wherein the specific-service network slice corresponds to a network slice optimized for a specific service provided by the service server (<NUM>).