Method, registration center and device for service discovery

TECHNICAL FIELD

0001This application relates to the communications field, and more specifically, to a service discovery method, a registration center, and a device.

BACKGROUND

0002Service registration and discovery is a directory service that facilitates a service definition, service selection, and a service execution policy. As a service supplier, a service provider registers service information of the service provider with a service registration center. The service registration center mainly provides central storage for all service registration information, and is responsible for sending a service registration information update notification to a service consumer in real time. The service consumer obtains needed service registration information from the service registration center, and invokes a service.

0003In a network service system, a network provider publishes a provided network service in a registration center, a client discovers a needed network service in the registration center, and the client obtains an end point of the network service. Service performance (for example, a supported protocol and a transmission mode) in a conventional network system is relatively simple. The client may select a proper service based on a service identity (Identity, ID). A fixed format is usually used during network service invocation. As the network system is upgraded, that is, as services tend to be diversified, the client cannot find a proper service by using a conventional solution. This deteriorates service quality.

0004<patcit id="pcit0001" dnum="US2014106497A1"><text>US 2014/106497 A1</text></patcit> discloses a service centric networking (SCN) framework over an ICN transport architecture to resolve a service name and a locator for a service provided in the architecture dynamically based on contextual information of a consumer of the service.

0005<patcit id="pcit0002" dnum="WO2016199515A1"><text>WO 2016/199515 Al </text></patcit>discloses a method and a program which are capable of appropriately selecting an edge server for providing a service to a terminal

0006<patcit id="pcit0003" dnum="US2008140797A1"><text>US 2008/140797 A1</text></patcit> discloses a home network system using an LnCP.

SUMMARY

0007This application provides a service discovery method, a registration center, and a device, so that a service consumer can find a proper service, thereby improving service quality.

0008The invention is defined by the independent claims. Advantageous embodiments of the invention are given in the dependent claims.

0009In the following, embodiments not falling within the scope of the claims are to be understood as examples useful for understanding the invention.

DESCRIPTION OF DRAWINGS

0010<ul id="ul0001" list-style="none" compact="compact"><li><figref idref="f0001">FIG. 1</figref> is an architectural diagram of service registration and discovery;</li><li><figref idref="f0001">FIG. 2</figref> is a schematic flowchart of network service registration and discovery;</li><li><figref idref="f0002">FIG. 3</figref> is a schematic diagram of a scenario in which service registration and discovery is applied to a mobile edge computing (Mobile Edge Computing, MEC) system;</li><li><figref idref="f0003">FIG. 4</figref> is a schematic diagram of a scenario in which service registration and discovery is applied to a services and systems aspects work group (Services and Systems Aspects Work Group, SA) 6 system;</li><li><figref idref="f0003">FIG. 5</figref> is a schematic diagram of a scenario in which service registration and discovery is applied to an SA2;</li><li><figref idref="f0004">FIG. 6</figref> is a schematic flowchart of a service discovery method according to an embodiment of this application;</li><li><figref idref="f0005">FIG. 7</figref> is a schematic diagram of a transmission mode according to an embodiment of this application;</li><li><figref idref="f0005">FIG. 8</figref> is a schematic diagram of an invocation mode according to an embodiment of this application;</li><li><figref idref="f0006">FIG. 9</figref> is a schematic diagram of a transmission protocol according to an embodiment of this application;</li><li><figref idref="f0007">FIG. 10</figref> is a schematic diagram of a transmission mode according to an embodiment of this application;</li><li><figref idref="f0008">FIG. 11</figref> is a schematic diagram of a location of an intermediate node according to an embodiment of this application;</li><li><figref idref="f0009">FIG. 12</figref> is a schematic diagram of an interaction procedure of a service discovery method according to an embodiment of this application;</li><li><figref idref="f0010">FIG. 13</figref> is a schematic diagram of an interaction procedure of a service discovery method according to another embodiment of this application;</li><li><figref idref="f0011">FIG. 14</figref> is a schematic diagram of an interaction procedure of a service discovery method according to another embodiment of this application;</li><li><figref idref="f0012">FIG. 15</figref> is a schematic block diagram of a registration center according to an embodiment of this application;</li><li><figref idref="f0012">FIG. 16</figref> is a schematic block diagram of a device according to an embodiment of this application;</li><li><figref idref="f0012">FIG. 17</figref> is a schematic block diagram of a device according to another embodiment of this application;</li><li><figref idref="f0013">FIG. 18</figref> is a schematic block diagram of a system according to an embodiment of this application;</li><li><figref idref="f0013">FIG. 19</figref> is a schematic structural diagram of a registration center according to an embodiment of this application;</li><li><figref idref="f0014">FIG. 20</figref> is a schematic structural diagram of a device according to an embodiment of this application; and</li><li><figref idref="f0014">FIG. 21</figref> is a schematic structural diagram of a device according to another embodiment of this application.</li></ul>

DESCRIPTION OF EMBODIMENTS

0011The following describes technical solutions of this application with reference to accompanying drawings.

0012<figref idref="f0001">FIG. 1</figref> is an architectural diagram of service registration and discovery. As shown in <figref idref="f0001">FIG. 1</figref>, service registration and discovery is a directory service that facilitates a service definition, service selection, and a service execution policy. As a service supplier, a service provider registers service information of the service provider with a service registration center. The service registration center mainly provides central storage for all service registration information, and is responsible for sending a service registration information update notification to a service consumer in real time. The service consumer obtains needed service registration information from the service registration center, and invokes a service.

0013Various elements in a service registration and discovery system are specifically defined as follows.

0014A service (Service) is a loosely coupled and coarse-grained autonomous component that can independently implement a logical function, and is available for invocation by a service consumer (an application/a network element or another component).

0015An end point (End point) is a discovery address notified to a service consumer by a service instance, and the service instance uses the address to expose information.

0016Contracts (Contracts) are agreements to which a service and a server invoker adhere, such as an application programming interface (Application Programming Interface, API) version, a uniform resource identifier (Uniform Resource Identifier, URI) directory, a quantity of parameters, and a message format.

0017A registration center (Service Registry) is used when a plurality of service instances are the same or a service instance needs to be dynamically generated. The service instance may provide an end point and a contract of the service instance for the registration center, so that a service invoker discovers and normally uses the service.

0018<figref idref="f0001">FIG. 2</figref> is a schematic flowchart of network service (Web Service) registration and discovery. 201. A network provider publishes a provided network service in a registration center. The network service published by the network provider in the registration center may be specifically characteristic information of the network service, such as at least one of a service identity (Identity, ID), a service name, a version number, a provider ID, an end point, an interface table, or a supplier.

0019202. A client discovers a needed network service in the registration center, and specifically the registration center searches for the characteristic information of the network service to find the proper network service.

0020203. The client obtains an end point of the network service.

0021<figref idref="f0002">FIG. 3</figref> shows a scenario in which service registration and discovery is applied to a mobile edge computing (Mobile Edge Computing, MEC) system. As shown in <figref idref="f0002">FIG. 3</figref>, the MEC system mainly includes a mobile edge orchestrator (Mobile Edge Orchestrator, MEO) and a mobile edge host (Mobile edge host). The MEO has a core management function in the MEC system. The mobile edge host mainly includes a mobile edge platform (Mobile edge platform), a virtualization infrastructure (Virtualization infrastructure), and a mobile edge application (Mobile edge application, ME app).

0022The mobile edge platform is a set of basic functions, is capable of running the mobile edge application in a specific virtualization infrastructure, and makes the mobile edge application be capable of providing and using a mobile edge service. The mobile edge application is an application instantiated in the virtualization infrastructure of the mobile edge host based on an MEO configuration or request. The mobile edge application includes a service provider (Service Provider) and a service consumer (Service Consumer). In addition, a registration center (Service registry) is located on the mobile edge platform, and a service instance may provide an end point and a contract of the service instance for the registration center, so that a service invoker discovers and normally uses the service instance.

0023An Mp1 interface and a Representational State Transfer (Restful) API are also defined in the MEC. The Mp1 interface supports service registration, service discovery, and service communication between the mobile edge platform and the mobile edge application. RESTful API is an API whose state is continually changed by a client as a representation manner of a network resource is continually obtained. Specifically, the service provider of the MEC registers a service with the mobile edge platform through the Mp1 interface, the service consumer discovers a service from the mobile edge platform through the Mp1 interface, and the service consumer invokes, through the RESTful application programming interface, the service provided by the service provider.

0024<figref idref="f0003">FIG. 4</figref> shows a scenario in which service registration and discovery is applied to a services and systems aspects work group (Services and Systems Aspects Work Group, SA) 6 system. As shown in <figref idref="f0003">FIG. 4</figref>, the SA6 system includes a mission-critical service (Mission Critical Service, MC Service), a service access server, a common service core (common service core, CSC), an external application, and an operations support system (Operation Support System, OSS). The MC service controls exposure of a service capability to the external application by using the service access server. The mission-critical service queries for and discovers a service on the service access server, and then implements service communication through a reused interface.

0025<figref idref="f0003">FIG. 5</figref> is a schematic diagram of a scenario in which service registration and discovery is applied to an SA2. As shown in <figref idref="f0003">FIG. 5</figref>, the SA2 system includes a network function repository function (Network Function Repository Function, NRF), a first network function (Network Function, NF) instance (NF Instance, NFI), a second network function instance, and management and orchestration (Management and Orchestration, MANO). The NRF maintains information about a deployed NFI during deployment, updating, and deletion of the network function instance. The NRF supports a service discovery function, receives a network function discovery request from the NFI, and provides found information about the NFI for the NFI.

0026To sum up, network service registration and discovery may be applied to the mobile edge computing (Mobile Edge Computing, MEC) system, the SA6 system, and the SA2 system. The MEC system is used as an example. In a conventional MEC system, a service consumer can only use a RESTful API to invoke a service of a service provider, and therefore the network provider and the discoverer do not need to consider a transmission interface. In other words, in the conventional solution, the network provider and the discoverer use the fixed interface.

0027In the European Telecommunications Standards Institute (European Telecommunications Standards Institute, ETSI) MEC#8B meeting, an MEC system not only supports a RESTful API, but also supports a transport-layer service interface used to support transmission with a low latency and a large data volume, for example, a Message Queuing Telemetry Transport (Message Queuing Telemetry Transport, MQTT) protocol, an Advanced Message Queuing Protocol (Advanced Message Queuing Protocol, AMQP), and a private Remote Procedure Call Protocol (Remote Procedure Call Protocol, RPC). In contrast, in the conventional technology, a proper service cannot be found based on a requirement for an interface, and consequently service quality is reduced.

0028<figref idref="f0004">FIG. 6</figref> is a schematic flowchart of a service discovery method according to an embodiment of this application. As shown in <figref idref="f0004">FIG. 6</figref>, the method is applied to a network service system. The network service system includes a registration center, a first device, and a second device. The method includes the following steps: <ul id="ul0002" list-style="none" compact="compact"><li>601. The registration center receives a service discovery request sent by the first device, where the service discovery request carries target parameter information of a service needed by the first device, the target parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is performing transmission directly or by using an intermediate node.</li><li>602. The registration center determines, based on a service parameter database, a target service corresponding to the target parameter information, where the service parameter database is used to store parameter information of different services of the second device.</li><li>603. The registration center sends a service response message to the first device, where the service response message includes description information of the target service.</li><li>604. The first device sends the invocation information to the second device, where the invocation information is used to invoke the target service.</li></ul>

0029The first device sends the service discovery request to the registration center, where the service discovery request is used to request the service, included in the second device, corresponding to the target parameter information, and the service discovery request carries the target parameter information. The service parameter database stores the parameter information of the different services of the second device, and all the services are in one-to-one correspondence to parameter information. Description information of each service corresponding to parameter information may be specifically an ID of the service. After receiving the service discovery request, the registration center searches the service parameter database for the target service satisfying the target parameter information, and sends the service response message including the description information of the target service to the first device, so that the first device can send the invocation information based on the description information of the target service, to invoke the target service of the second device. In other words, a needed service can be selected more accurately for the first device in this embodiment of this application, thereby improving service quality.

0030The target parameter information of the service needed by the first device may be parameter information corresponding to the service needed by the first device. For example, the target parameter information may be the information about the first transmission mode, the information about the invocation mode, the information about the transmission protocol, the information about the second transmission mode, or the like that is used when the first device sends the invocation information to the second device after selecting the target service and receives a response message sent by the second device based on the invocation information.

0031It should be noted that the service discovery request sent by the first device to the registration center may further carry at least one of a service ID, a service name, a version number, a provider ID, an end point, an interface table, or a supplier.

0032It should be understood that a correspondence between a service and parameter information may be represented by using a mapping relationship, in another form, or the like. This is not limited in this application.

0033It should also be understood that in the service parameter database, each service is corresponding to one piece of parameter information, and the parameter information also includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode.

0034It should also be understood that the first device may be a hardware device or a software application, and the second device may be a hardware device or a software application. In addition, the first device may be the same as the second device. This is not limited in this application.

0035To sum up, according to the service discovery method in this embodiment of this application, the registration center receives the service discovery request sent by the first device, where the service discovery request carries the target parameter information of the service needed by the first device, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode. The registration center determines, based on the service parameter database, the target service corresponding to the target parameter information; and sends the service response message including the description information of the target service to the first device. In this way, among diversified services, a proper service can be found for the first device based on service supporting parameter information. Therefore, service quality can be improved, and system processing efficiency can be enhanced. In addition, according to the service discovery method in this embodiment of this application, management and extension of the network system can be facilitated.

0036Optionally, the registration center may receive a registration request, where the registration request includes parameter information of a first service of the second device; and the registration center stores the parameter information of the first service into the service parameter database. The first service may be any one of services supported by the second device. To be specific, the registration center may store parameter information of a plurality of different services into the parameter database; and after receiving the service discovery request, query the parameter database for parameter information satisfying a requirement, and determine a service corresponding to the parameter information satisfying the requirement.

0037It should be noted that, when the second device sends the registration request to the registration center, the parameter information included in the registration request is the same as the parameter information included in the service discovery request, and also includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode. The information about the first transmission mode is the in-band identifier or the out-of-band identifier, the in-band identifier is used to indicate the transmission mode in which the invocation information is added to the data for transmission, the out-of-band identifier is used to indicate the transmission mode in which the data and the invocation information are separately transmitted, the invocation mode is the one-request-one-response or the one-request-multiple-response, the transmission protocol is any one of the Representational State Transfer Application Programming Interface Protocol, the Advanced Message Queue Interface Protocol, the Message Queuing Telemetry Transport Protocol, and the Remote Procedure Call Protocol, and the second transmission mode is performing transmission directly or by using the intermediate node.

0038It should be understood that the registration request may further carry at least one of a service ID, a service name, a version number, a provider ID, an end point, an interface table, or a supplier. Optionally, if the target parameter information includes the information about the first transmission mode, the information about the first transmission mode may be the out-of-band identifier or the in-band identifier. The in-band identifier is used to indicate the transmission mode in which the invocation information is added to the data for transmission, and the out-of-band identifier is used to indicate the transmission mode in which the data and the invocation information are separately transmitted. If the information about the first transmission mode included in the target parameter information is the in-band identifier, the registration center determines a service corresponding to parameter information that is in the service parameter database and that includes the in-band identifier, as the target service. Likewise, if the information about the first transmission mode included in the target parameter information is the out-of-band identifier, the registration center determines a service corresponding to parameter information that is in the service parameter database and that includes the out-of-band identifier, as the target service.

0039Specifically, if the information about the first transmission mode included in the target parameter information is the in-band identifier, the invocation information to be sent by the first device to the second device may be added to the data for transmission, for example, by using a Transmission Control Protocol (Transmission Control Protocol, TCP) option (option). As shown in <figref idref="f0005">FIG. 7</figref>, if the information about the first transmission mode included in the target parameter information is the out-of-band identifier, the invocation information and the data that are sent by the first device to the second device may be separately transmitted. The registration center selects, for the first device, the second device satisfying the requirement, so that the first device can obtain the service of high quality.

0040As shown in <figref idref="f0005">FIG. 8</figref>, the target parameter information includes the information about the invocation mode, where the invocation mode is the one-request-one-response or the one-request-multiple-response. The one-request-one-response is a service that, after the first device sends invocation information to the second device once, the second device responds to an invocation information request once. In this way, services in need of different contracts can be handled separately, thereby enhancing processing efficiency. The one-request-multiple-response is a service that, after the first device sends invocation information to the second device once, the second device may respond to an invocation information request a plurality of times, that is, validity of one subscription lasts for a long time. This avoids sending the invocation information a plurality of times between devices that need a same service, thereby reducing power consumption of the first device.

0041If the invocation mode is the one-request-one-response, the registration center determines a service corresponding to parameter information that is in the service parameter database and that includes information about the one-request-one-response, as the target service. Likewise, if the invocation mode is the one-request-multiple-response, the registration center determines a service corresponding to parameter information that is in the service parameter database and that includes information about the one-request-multiple-response, as the target service.

0042Optionally, the target parameter information includes the information about the transmission protocol, where the transmission protocol is any one of the RESTful API protocol, the AMQP, the MQTT protocol, and the RPC protocol. <figref idref="f0006">FIG. 9</figref> is a schematic diagram of a RESTful API protocol and an AMQP protocol. If the transmission protocol is the AMQP protocol, the registration center determines a service corresponding to parameter information that is in the service parameter database and that includes information about the AMQP protocol, as the target service. Likewise, if the transmission protocol is any one of the RESTful API protocol, the MQTT protocol, and the RPC protocol, the registration center determines a service corresponding to parameter information that is in the service parameter database and that includes information about the corresponding interface protocol, as the target service. Optionally, the target parameter information includes the information about the second transmission mode. As shown in <figref idref="f0007">FIG. 10</figref>, the second transmission mode is performing transmission directly or by using an intermediate node. If the second transmission mode is performing transmission directly, the registration center determines a service corresponding to parameter information that is in the service parameter database and that includes information indicating that transmission is performed directly, as the target service. Likewise, if the second transmission mode is performing transmission by using the intermediate node, the registration center determines a service corresponding to parameter information that is in the service parameter database and that includes information indicating that transmission is performed by using the intermediate node, as the target service. In this way, the second device can allow a first device corresponding to a trusted application or an application in a same domain to directly access the service, but allow a first device corresponding to an untrusted application or an application in another domain to access the service only after authentication or message format conversion is performed by an intermediate entity. This improves security performance of the second device.

0043Optionally, the target parameter information further includes a location of the intermediate node, and as shown in <figref idref="f0008">FIG. 11</figref>, the intermediate node is located on a third-party device, the registration center, or the second device. The determining, by the registration center when the second transmission mode is performing transmission by using the intermediate node, a service corresponding to parameter information that is in the service parameter database and that includes information indicating that transmission is performed by using the intermediate node, as the target service may be specifically: determining, by the registration center when the second transmission mode is performing transmission by using the intermediate node and the intermediate node is located at the third-party device, a service corresponding to parameter information that is in the service parameter database and that includes information indicating that transmission is performed by using the intermediate node and that the intermediate node is located at the third-party device, as the target service.

0044It should be noted that, when the target parameter information includes the invocation mode at least one of the information about the first transmission mode, the information about the invocation mode, the information about the transmission protocol, and the information about the second transmission mode, the registration center may determine any one of services corresponding to all information that is in the service parameter database and that is included in the target parameter information, as the target service; or the registration center may determine a service with a higher proportion among services corresponding to all information, as the target service. The system may preset a rule for the registration center to determine a target service. This is not limited in this application.

0045Optionally, the network service system is a mobile edge computing MEC system; the MEC system includes a mobile edge orchestrator and a mobile edge host; the mobile edge host includes a mobile edge platform, a first mobile edge application, and a second mobile edge application; the mobile edge platform is corresponding to the registration center, the first mobile edge application is corresponding to the first device, and the second mobile edge application is corresponding to the second device; and the mobile edge orchestrator is configured to manage the first mobile edge application and the second mobile edge application.

0046Specifically, the first mobile edge application may select different interface protocols such as the MQTT protocol, the AMQP, and the private Remote Procedure Call RPC Protocol. In other words, a proper service is found based on a requirement for an interface protocol, thereby improving service quality.

0047Optionally, the network service system is an SA6 system. The SA6 system includes a service registration server, a mission-critical service, and an external application; and the service registration server is corresponding to the registration center, the external application is corresponding to the first device, and the mission-critical service is corresponding to the second device.

0048In the SA6, the external application located in a trusted domain different from that of the mission-critical service uses a service access server. In this case, a service is used to implement an application for users in different trusted domains/deployment domains. A trusted application or an application in a same domain can directly access the service, whereas an untrusted application or an application in another domain can access the service only after authentication or message format conversion is performed by an intermediate entity.

0049Optionally, the network service system is an SA2 system. The SA2 system includes a network function repository function, a first network function instance, and a second network function instance; and the network function repository function is corresponding to the registration center, the first network function instance is corresponding to the first device, and the second network function instance is corresponding to the second device.

0050In the SA2, an attribute of a network function (Network Function, NF) is the same as an attribute of a service, and there may be a one-to-one mapping relationship between the network function and the service. The NF may be targeted for a third party and a network element in a visited public land mobile network (Visited Public Land Mobile Network, VPLMN), or may be targeted for a network element in a home public land mobile network (Home Public Land Mobile Network, HPLMN), and interfaces and message obtaining manners may be different. For example, in an evolved packet system (Evolved Packet System, EPS), a message obtaining procedure for an S5 interface between a serving gateway (Serving Gateway, S-GW) and an H-packet data gateway (Packet Data Gateway, PGW) is different from a message obtaining procedure for an S8 interface between an S-GW and a V-PGW. A network exposure function (Network Exposure Function, NEF) is targeted for an internal network element and a third party in the future, and interfaces and message obtaining manners may also be different. In this way, a proper second network function instance can be selected for the first network function instance more accurately based on the parameter information, thereby improving service quality.

0051To sum up, according to the service discovery method in this embodiment of this application, the registration center receives the service discovery request sent by the first device, where the service discovery request carries the target parameter information of the service needed by the first device, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; determines, based on the service parameter database, the target service corresponding to the target parameter information; and sends the service response message including the description information of the target service to the first device. In this way, among diversified services, a proper service can be found for the first device based on service supporting parameter information. Therefore, service quality can be improved, and system processing efficiency can be enhanced.

0052<figref idref="f0009">FIG. 12</figref> is a schematic diagram of an interaction procedure of a service discovery method according to an embodiment of this application. Various same terms in this embodiment have same meanings as those in the foregoing embodiments.

0053The method may be applied to the MEC system shown in <figref idref="f0002">FIG. 3</figref>. A registration center may be corresponding to a mobile edge platform or may be an independent apparatus located on a mobile edge platform of a mobile edge host. A first device may be corresponding to a first mobile edge application, in the mobile edge host, used to request a service. A second device may be corresponding to a second mobile edge application, in the mobile edge host, used to provide a service. In other words, the first mobile edge application is a "service consumer", and the second mobile edge application is a "service provider".

0054An application developer may implement two applications according to an agreement (for example, a development manual or the 3rd Generation Partnership Project (the 3rd Generation Partnership Project, 3GPP) standard): implement an interface in the agreement, and invoke a related interface function according to the agreement. Before implementing this embodiment of this application, the MEC system deploys the two applications on devices in the MEC system by using an MEO.

00551201. The MEO deploys a mission-critical service application installation package (App package), including an application resource requirement, an application file, a needed-service description, and the like.

00561202. After receiving an application instantiation request, the MEO controls the application installation package to generate a provider application instance, that is, a service that can be provided, in the second mobile edge application.

00571203. The second mobile edge application sends a registration request to the mobile edge platform, where the registration request includes service supporting parameter information.

0058Specifically, the parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is performing transmission directly or by using an intermediate node.

00591204. The mobile edge platform stores the service and the parameter information of the service into a service parameter database. Specifically, the parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode.

0060Because registration requests may be sent to the mobile edge platform for different services, the service parameter database stores a plurality of different services and parameter information corresponding to the services.

00611205. After receiving a consumer application instantiation request, the MEO may control the application installation package to generate a consumer application instance, that is, a needed service, in the first mobile edge application.

0062It should be understood that if the mobile edge platform has stored the parameter information of the different services, step 1205 may be directly performed, and steps 1201 to 1204 do not need to be performed.

00631206. The first mobile edge application sends a service discovery request to the mobile edge platform, where the service discovery request includes parameter information of the needed service, and the parameter information may be represented as target parameter information. Specifically, the target parameter information also includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode.

00641207. The mobile edge platform determines, based on the parameter information of the service stored in the service parameter database, a target service satisfying the target parameter information.

00651208. The mobile edge platform sends a service response message to the first mobile edge application, where the service response message includes description information of the target service.

00661209. The first mobile edge application triggers an invocation procedure based on the service response message.

00671210. The first mobile edge application performs the invocation procedure based on the description information of the target service in the service response message.

0068Specifically, the invocation information may be sent to the second mobile edge application, to invoke the target service in the second mobile edge application. The invocation procedure includes, for example, preparing a to-be-requested resource, storing a context, querying for the context, and returning content or a result of invocation.

0069To sum up, according to the service discovery method in this embodiment of this application, the mobile edge platform receives the service discovery request sent by the first mobile edge application, where the service discovery request carries the target parameter information of the service needed by the first mobile edge application, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission ; determines, based on the service parameter database, the target service corresponding to the target parameter information; and sends the service response message including the description information of the target service to the first mobile edge application. In this way, among diversified services, a proper service can be found for the first mobile edge application based on application service supporting parameter information. Especially among application services that support a plurality of interface protocols or different invocation modes, the first mobile edge application can select a satisfactory interface protocol and invocation mode for transmitting the invocation information, thereby improving transmission efficiency.

0070<figref idref="f0010">FIG. 13</figref> is a schematic diagram of an interaction procedure of a service discovery method according to another embodiment of this application. Various same terms in this embodiment have same meanings as those in the foregoing embodiments.

0071The method may be applied to the SA6 system shown in <figref idref="f0003">FIG. 4</figref>. A registration center may be corresponding to a service access server, a first device may be corresponding to an external application used to request a service, and a second device may be corresponding to a mission-critical service used to provide a service. In other words, the external application is a "service consumer", and the mission-critical service is a "service provider".

0072An application developer may implement two applications according to an agreement (for example, a development manual or the 3GPP standard): implement an interface in the agreement, and invoke a related interface function according to the agreement. Before implementing this embodiment of this application, the SA6 system deploys the two applications on devices in the SA6 system by using an OSS.

00731301. The OSS deploys a mission-critical service installation package (MC package).

00741302. After receiving an application instantiation request, the OSS controls the application installation package to generate a provider application instance, that is, a service that can be provided, in the mission-critical service.

00751303. The mission-critical service sends a registration request to the service access server, where the registration request includes service supporting parameter information.

0076Specifically, the parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is performing transmission directly or by using an intermediate node.

00771304. The service access server stores the service and the parameter information of the service into a service parameter database. Specifically, the parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode.

0078Because registration requests may be sent to the service access server for different services, the service parameter database stores a plurality of different services and parameter information corresponding to the services.

00791305. After receiving a consumer application instantiation request, the OSS may control the application installation package to generate a consumer application instance, that is, a needed service, in the external application.

0080It should be understood that if the service access server has stored the parameter information of the different services, step 1305 may be directly performed, and steps 1301 to 1304 do not need to be performed.

00811306. The external application sends a service discovery request to the service access server, where the service discovery request includes parameter information of the needed service, and the parameter information may be represented as target parameter information. Specifically, the target parameter information also includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode.

00821307. The service access server determines, based on the parameter information of the service stored in the service parameter database, a target service satisfying the target parameter information.

00831308. The service access server sends a service response message to the external application, where the service response message includes description information of the target service.

00841309. The external application triggers an invocation procedure based on the service response message.

00851310. The external application performs the invocation procedure based on the description information of the target service in the service response message.

0086Specifically, the invocation information may be sent to the mission-critical service, to invoke the target service in the mission-critical service. The invocation procedure includes, for example, preparing a to-be-requested resource, storing a context, querying for the context, and returning content or a result of invocation.

0087To sum up, according to the service discovery method in this embodiment of this application, the service access server receives the service discovery request sent by the external application, where the service discovery request carries the target parameter information of the service needed by the external application, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; determines, based on the service parameter database, the target service corresponding to the target parameter information; and sends the service response message including the description information of the target service to the external application. In this way, among diversified services, a proper service can be found for the external application based on service supporting parameter information. Especially, a trusted application or an application in a same domain can directly access the service, whereas an untrusted application or an application in another domain can access the service only after authentication, format conversion, or the like is performed by an intermediate entity. This improves security performance of the network system.

0088<figref idref="f0011">FIG. 14</figref> is a schematic diagram of an interaction procedure of a service discovery method according to an embodiment of this application. Various same terms in this embodiment have same meanings as those in the foregoing embodiments.

0089The method may be applied to the SA2 system shown in <figref idref="f0003">FIG. 5</figref>. A registration center may be corresponding to a network function repository function, a first device may be corresponding to a first network function instance used to request a service, and a second device may be corresponding to a second network function instance used to provide a service. In other words, the first network function instance is a "service consumer", and the second network function instance is a "service provider".

0090An application developer may implement two applications according to an agreement (for example, a development manual or the 3GPP standard): implement an interface in the agreement, and invoke a related interface function according to the agreement. Before implementing this embodiment of this application, the SA2 system deploys the two applications on devices in the SA2 system by using MANO.

00911401. The MANO deploys a network function installation package (Network Function Package, NF package).

00921402. After receiving an application initiation request, the MANO controls the application installation package to generate a provider application instance, that is, a service that can be provided, in the second network function instance.

00931403. The second network function instance sends a registration request to the network function repository function, where the registration request includes service supporting parameter information.

0094Specifically, the parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is performing transmission directly or by using an intermediate node.

00951404. The network function repository function stores the service and the parameter information of the service into a service parameter database. Specifically, the parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode.

0096Because registration requests may be sent to the network function repository function for different services, the service parameter database stores a plurality of different services and parameter information corresponding to the services.

00971405. After receiving a consumer application instantiation request, the MANO may control the application installation package to generate a consumer application instance, that is, a needed service, in the first network function instance.

0098It should be understood that if the network function repository function has stored the parameter information of the different services, step 1405 may be directly performed, and steps 1401 to 1404 do not need to be performed.

00991406. The first network function instance sends a service discovery request to the network function repository function, where the service discovery request includes parameter information of the needed service, and the parameter information may be represented as target parameter information. Specifically, the target parameter information also includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode.

01001407. The network function repository function determines, based on the parameter information of the service stored in the service parameter database, a target service satisfying the target parameter information.

01011408. The network function repository function sends a service response message to the first network function instance, where the service response message includes description information of the target service.

01021409. The first network function instance triggers an invocation procedure based on the service response message.

01031410. The first network function instance performs the invocation procedure based on the description information of the target service in the service response message.

0104Specifically, the invocation information may be sent to the second network function instance, to invoke the target service in the second network function instance. The invocation procedure includes, for example, preparing a to-be-requested resource, storing a context, querying for the context, and returning content or a result of invocation.

0105To sum up, according to the service discovery method in this embodiment of this application, the network function repository function receives the service discovery request sent by the first network function instance, where the service discovery request carries the target parameter information of the service needed by the first network function instance, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; determines, based on the service parameter database, the target service corresponding to the target parameter information; and sends the service response message including the description information of the target service to the first network function instance. In this way, among diversified services, a proper service can be found for the first network function instance based on service supporting parameter information. Especially, selecting a proper transmission protocol can normalize interface invocation, that is, appropriately allocate an interface to improve the service, thereby enhancing processing efficiency of the network system.

0106The foregoing details the service discovery methods according to the embodiments of this application, and the following describes service discovery devices according to embodiments of this application.

0107<figref idref="f0012">FIG. 15</figref> is a schematic block diagram of a registration center 1500 according to an embodiment of this application. As shown in <figref idref="f0012">FIG. 15</figref>, the registration center 1500 includes: <ul id="ul0003" list-style="none" compact="compact"><li>a receiving module 1510, configured to receive a service discovery request sent by a first device, where the service discovery request carries target parameter information of a service needed by the first device, the target parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission between the first device and a second device, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted between the first device and the second device, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is transmitting information between the first device and the second device directly or by using an intermediate node;</li><li>a processing module 1520, configured to determine, based on a service parameter database, a target service corresponding to the target parameter information, where the service parameter database is used to store parameter information of different services of the second device; and</li><li>a sending module 1530, configured to send a service response message to the first device, where the service response message includes description information of the target service.</li></ul>

0108The registration center in this embodiment of this application receives the service discovery request sent by the first device, where the service discovery request carries the target parameter information of the service needed by the first device, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; determines, based on the service parameter database, the target service corresponding to the target parameter information; and sends the service response message including the description information of the target service to the first device. In this way, among diversified services, a proper service can be found for the first device based on service supporting parameter information. Therefore, service quality can be improved, and system processing efficiency can be enhanced.

0109Optionally, the receiving module 1510 is further configured to receive a registration request sent by the second device, where the registration request includes parameter information of a first service of the second device; and the processing module 1520 is further configured to store the parameter information of the first service into the service parameter database.

0110Optionally, the target parameter information includes the information about the first transmission mode; and the processing module 1520 is specifically configured to: if the information about the first transmission mode is the in-band identifier, determine a service corresponding to parameter information that is in the service parameter database and that includes the in-band identifier, as the target service.

0111The target parameter information includes the information about the invocation mode; and the processing module 1520 is specifically configured to: if the invocation mode is the one-request-one-response, determine a service corresponding to parameter information that is in the service parameter database and that includes information about the one-request-one-response, as the target service.

0112Optionally, the target parameter information includes the information about the transmission protocol; and the processing module 1520 is specifically configured to: when the transmission protocol is the Advanced Message Queue Interface Protocol, determine a service corresponding to parameter information that is in the service parameter database and that includes information about the Advanced Message Queue Interface Protocol, as the target service.

0113Optionally, the target parameter information includes the second transmission mode; and the processing module 1520 is specifically configured to: determine, for the registration center when the second transmission mode is transmitting the information between the first device and the second device by using the intermediate node, a service corresponding to parameter information that is in the service parameter database and that includes information indicating that transmission is performed by using the intermediate node, as the target service.

0114Optionally, the target parameter information further includes location information of the intermediate node, and the intermediate node is located on a third-party device, the registration center, or the second device; and the processing module 1520 is specifically configured to: determine, when the second transmission mode is performing transmission by using the intermediate node and the intermediate node is located at the third-party device, a service corresponding to parameter information that is in the service parameter database and that includes information indicating that transmission is performed by using the intermediate node and that the intermediate node is located at the third-party device, as the target service. Optionally, the network service system is a mobile edge computing system; the mobile edge computing system includes a mobile edge orchestrator and a mobile edge host; the mobile edge host includes a mobile edge platform, a first mobile edge application, and a second mobile edge application; the mobile edge platform is corresponding to the registration center, the first mobile edge application is corresponding to the first device, and the second mobile edge application is corresponding to the second device; and the mobile edge orchestrator is configured to manage the first mobile edge application and the second mobile edge application.

0115Optionally, the network service system is a services and systems aspects work group 6 system; the services and systems aspects work group 6 system includes a service registration server, a mission-critical service, and an external application; and the service registration server is corresponding to the registration center, the external application is corresponding to the first device, and the mission-critical service is corresponding to the second device.

0116Optionally, the network service system is a services and systems aspects work group 2 system; the services and systems aspects work group 2 system includes a network function repository function, a first network function instance, and a second network function instance; and the network function repository function is corresponding to the registration center, the first network function instance is corresponding to the first device, and the second network function instance is corresponding to the second device.

0117To sum up, the registration center in this embodiment of this application receives the service discovery request sent by the first device, where the service discovery request carries the target parameter information of the service needed by the first device, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; determines, based on the service parameter database, the target service corresponding to the target parameter information; and sends the service response message including the description information of the target service to the first device. In this way, among diversified services, a proper service can be found for the first device based on service supporting parameter information. Therefore, service quality can be improved, and system processing efficiency can be enhanced.

0118<figref idref="f0012">FIG. 16</figref> is a schematic block diagram of a device 1600 according to an embodiment of this application. As shown in <figref idref="f0012">FIG. 16</figref>, the device is applied to a network service system. The network service system includes a registration center, the device, and a second device. The device 1600 is corresponding to the first device in the foregoing embodiments, and the device 1600 includes: <ul id="ul0004" list-style="none" compact="compact"><li>a sending module 1610, configured to send a service discovery request, where the service discovery request carries target parameter information of a service needed by the first device and the service discovery request is used to determine, based on a service parameter database, a target service corresponding to the target parameter information, the target parameter information includes the information about the invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission between the first device and the second device, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted between the first device and the second device, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is transmitting information between the first device and the second device directly or by using an intermediate node; and</li><li>a receiving module 1620, configured to receive a service response message, where the service response message includes description information of the target service; and</li><li>the sending module 1610 is further configured to send the invocation information to the second device, where the invocation information is used to invoke the target service.</li></ul>

0119To sum up, the first device in this embodiment of this application sends the service discovery request to the registration center, where the service discovery request carries the target parameter information of the service needed by the first device and the service discovery request is used to determine, based on the service parameter database, the target service corresponding to the target parameter information, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; and receives the service response message, sent by the registration center, including the description information of the target service. In this way, among diversified services, a proper service can be found for the first device based on service supporting parameter information. Therefore, service quality can be improved, and system processing efficiency can be enhanced.

0120Optionally, when the second transmission mode is transmitting the information between the first device and the second device by using the intermediate node, the target parameter information further includes a location of the intermediate node, and the intermediate node is located on a third-party device, the registration center, or the second device.

0121Optionally, the network service system is a mobile edge computing system; the mobile edge computing system includes a mobile edge orchestrator and a mobile edge host; the mobile edge host includes a mobile edge platform, a first mobile edge application, and a second mobile edge application; the mobile edge platform is corresponding to the registration center, the first mobile edge application is corresponding to the device, and the second mobile edge application is corresponding to the second device; and the mobile edge orchestrator is configured to manage the first mobile edge application and the second mobile edge application.

0122Optionally, the network service system is a services and systems aspects work group 6 system; the services and systems aspects work group 6 system includes a service registration server, a mission-critical service, and an external application; and the service registration server is corresponding to the registration center, the external application is corresponding to the device, and the mission-critical service is corresponding to the second device.

0123Optionally, the network service system is a services and systems aspects work group 2 system; the services and systems aspects work group 2 system includes a network function repository function, a first network function instance, and a second network function instance; and the network function repository function is corresponding to the registration center, the first network function instance is corresponding to the device, and the second network function instance is corresponding to the second device.

0124To sum up, the first device in this embodiment of this application sends the service discovery request to the registration center, where the service discovery request carries the target parameter information of the service needed by the first device and the service discovery request is used to determine, based on the service parameter database, the target service corresponding to the target parameter information, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; and receives the service response message, sent by the registration center, including the description information of the target service. In this way, among diversified services, a proper service can be found for the first device based on service supporting parameter information. Therefore, service quality can be improved, and system processing efficiency can be enhanced.

0125<figref idref="f0012">FIG. 17</figref> is a schematic block diagram of a device 1700 according to an embodiment of this application. As shown in <figref idref="f0012">FIG. 17</figref>, the device is applied to a network service system. The network service system includes a registration center, a first device, and the device. The device 1700 is corresponding to the second device in the foregoing embodiments, and the device 1700 includes: <ul id="ul0005" list-style="none" compact="compact"><li>a sending module 1710, configured to send a registration request to the registration center, where the registration request includes parameter information of a first service, so that the registration center stores the parameter information of the first service into a service parameter database, where the service parameter database is used to determine a target service corresponding to target parameter information, the target parameter information is parameter information of a service needed by the first device, the target parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission between the first device and the second device, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted between the first device and the second device, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is transmitting information between the first device and the second device directly or by using an intermediate node; and</li><li>a receiving module 1720, configured to receive the invocation information sent by the first device, where the invocation information is used to invoke the target service.</li></ul>

0126To sum up, the second device in this embodiment of this application sends the registration request to the registration center, so that the parameter database of the registration center stores parameter information of a plurality of different services. After receiving a service discovery request, the registration center queries the parameter database for parameter information satisfying a requirement, determines a service corresponding to the parameter information satisfying the requirement, and sends the description information of the service to the first device. In this way, the first device can invoke the service of the second device, and therefore the first device can obtain the service of high quality.

0127Optionally, when the second transmission mode is transmitting the information between the first device and the second device by using the intermediate node, the target parameter information further includes a location of the intermediate node, and the intermediate node is located on a third-party device, the registration center, or the device.

0128Optionally, the network service system is a mobile edge computing system; the mobile edge computing system includes a mobile edge orchestrator and a mobile edge host; the mobile edge host includes a mobile edge platform, a first mobile edge application, and a second mobile edge application; the mobile edge platform is corresponding to the registration center, the first mobile edge application is corresponding to the first device, and the second mobile edge application is corresponding to the device; and the mobile edge orchestrator is configured to manage the first mobile edge application and the second mobile edge application.

0129Optionally, the network service system is a services and systems aspects work group 6 system; the services and systems aspects work group 6 system includes a service registration server, a mission-critical service, and an external application; and the service registration server is corresponding to the registration center, the external application is corresponding to the first device, and the mission-critical service is corresponding to the device.

0130Optionally, the network service system is a services and systems aspects work group 2 system; the services and systems aspects work group 2 system includes a network function repository function, a first network function instance, and a second network function instance; and the network function repository function is corresponding to the registration center, the first network function instance is corresponding to the first device, and the second network function instance is corresponding to the device.

0131To sum up, the second device in this embodiment of this application sends the registration request to the registration center, so that the parameter database of the registration center stores the parameter information of the plurality of different services. After receiving the service discovery request, the registration center queries the parameter database for the parameter information satisfying the requirement, determines the service corresponding to the parameter information satisfying the requirement, and sends the description information of the service to the first device. In this way, the first device can invoke the service of the second device, and therefore the first device can obtain the service of high quality.

0132<figref idref="f0013">FIG. 18</figref> shows a service discovery system 1800 according to an embodiment of this application. The system 1800 includes: the registration center 1500 in the embodiment shown in <figref idref="f0012">FIG. 15</figref>, the device 1600 in the embodiment shown in <figref idref="f0012">FIG. 16</figref>, and the device 1700 in the embodiment shown in <figref idref="f0012">FIG. 17</figref>. <figref idref="f0013">FIG. 19</figref> is a schematic structural diagram of a registration center according to an embodiment of this application. As shown in <figref idref="f0013">FIG. 19</figref>, the registration center includes at least one processor 1902 (for example, a general purpose processor CPU with computing and processing capabilities, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA)). The processor 1902 is configured to manage and schedule modules and components in the registration center. The processing module 1520 in the embodiment shown in <figref idref="f0012">FIG. 15</figref> may be implemented by the processor 1902. The registration center further includes at least one transceiver 1905 (receiver/transmitter) and a memory 1906. The receiving module 1510 and the sending module 1530 in the embodiment shown in <figref idref="f0012">FIG. 15</figref> may be implemented by the transceiver 1905. The components of the registration center use an internal connection path to communicate with each other and transmit a control signal and/or a data signal.

0133The method disclosed in the embodiments of this application may be applied to the processor 1902, or may be used to execute an executable module, such as a computer program, stored in the memory 1906. The memory 1906 may include a high-speed random access memory (Random Access Memory, RAM), or may further include a non-volatile memory (non-volatile memory). The memory 1906 may include a read-only memory and a random access memory, and provide signaling, data, a program, or the like that is necessary, for the processor. A part of the memory may further include a non-volatile random access memory (NVRAM). A communication connection to at least one other network element is implemented (in a wired or wireless manner) by using at least one transceiver 1905.

0134In some implementations, the memory 1906 stores a program 19061, and the processor 1902 executes the program 19061, to perform the following operations: <ul id="ul0006" list-style="none" compact="compact"><li>receiving a service discovery request sent by a first device, where the service discovery request carries target parameter information of a service needed by the first device, the target parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission between the first device and a second device, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted between the first device and the second device, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is transmitting information between the first device and the second device directly or by using an intermediate node;</li><li>determining, based on a service parameter database, a target service corresponding to the target parameter information, where the service parameter database is used to store parameter information of different services of the second device; and</li><li>sending a service response message to the first device, where the service response message includes description information of the target service.</li></ul>

0135It should be noted that the registration center may be specifically the registration center in the embodiment shown in <figref idref="f0012">FIG. 15</figref>, and may be configured to perform each step and/or procedure corresponding to the registration center in the method embodiment.

0136It can be learned from the foregoing technical solution provided in this embodiment of this application that, the service discovery request sent by the first device is received, where the service discovery request carries the target parameter information of the service needed by the first device, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; the target service corresponding to the target parameter information is determined based on the service parameter database; and the service response message including the description information of the target service is sent to the first device. In this way, among diversified services, a proper service can be found for the first device based on service supporting parameter information. Therefore, service quality can be improved, and system processing efficiency can be enhanced.

0137<figref idref="f0014">FIG. 20</figref> is a schematic structural diagram of a device according to an embodiment of this application. As shown in <figref idref="f0014">FIG. 20</figref>, the device includes at least one processor 2002 (for example, a general purpose processor CPU with computing and processing capabilities, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA)). The processor 2002 is configured to manage and schedule modules and components in the device. The device further includes at least one transceiver 2005 (receiver/transmitter) and a memory 2006. The sending module 1610 and the receiving module 1620 in the embodiment shown in <figref idref="f0012">FIG. 16</figref> may be implemented by the transceiver 2005. The components of the device use an internal connection path to communicate with each other and transmit a control signal and/or a data signal.

0138The method disclosed in the embodiments of this application may be applied to the processor 2002, or may be used to execute an executable module, such as a computer program, stored in the memory 2006. The memory 2006 may include a high-speed random access memory (Random Access Memory, RAM), or may further include a non-volatile memory (non-volatile memory). The memory 2006 may include a read-only memory and a random access memory, and provide signaling, data, a program, or the like that is necessary, for the processor. A part of the memory may further include a non-volatile random access memory (NVRAM). A communication connection to at least one other network element is implemented (in a wired or wireless manner) by using at least one transceiver 2005.

0139In some implementations, the memory 2006 stores a program 20061, and the processor 2002 executes the program 20061, to perform the following operations: <ul id="ul0007" list-style="none" compact="compact"><li>sending a service discovery request, where the service discovery request carries target parameter information of a service needed by the device and the service discovery request is used to determine, based on a service parameter database, a target service corresponding to the target parameter information, the target parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission between the first device and a second device, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted between the first device and the second device, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is transmitting information between the first device and the second device directly or by using an intermediate node;</li><li>receiving a service response message, where the service response message includes description information of the target service; and</li><li>sending the invocation information to the second device, where the invocation information is used to invoke the target service.</li></ul>

0140It can be learned from the foregoing technical solution provided in this embodiment of this application that, the service discovery request is sent to the registration center, where the service discovery request carries the target parameter information of the service needed by the first device and the service discovery request is used to determine, based on the service parameter database, the target service corresponding to the target parameter information, and the target parameter information includes the information about the invocation mode and may include the at least one of the information about the first transmission mode, the information about the transmission protocol, and the information about the second transmission mode; and the service response message, sent by the registration center, including the description information of the target service is received. In this way, among diversified services, a proper service can be found for the first device based on service supporting parameter information. Therefore, service quality can be improved, and system processing efficiency can be enhanced.

0141<figref idref="f0014">FIG. 21</figref> is a schematic structural diagram of a device according to an embodiment of this application. As shown in <figref idref="f0014">FIG. 21</figref>, the device includes at least one processor 2102 (for example, a general purpose processor CPU with computing and processing capabilities, a digital signal processor (DSP), an application-specific integrated circuit (ASIC), or a field-programmable gate array (FPGA)). The processor 2102 is configured to manage and schedule modules and components in the device. The device further includes at least one transceiver 2105 (receiver/transmitter) and a memory 2106. The sending module 1710 and the receiving module 1720 in the embodiment shown in <figref idref="f0012">FIG. 17</figref> may be implemented by the transceiver 2105. The components of the device use an internal connection path to communicate with each other and transmit a control signal and/or a data signal.

0142The method disclosed in the embodiments of this application may be applied to the processor 2102, or may be used to execute an executable module, such as a computer program, stored in the memory 2106. The memory 2106 may include a high-speed random access memory (Random Access Memory, RAM), or may further include a non-volatile memory (non-volatile memory). The memory 2106 may include a read-only memory and a random access memory, and provide signaling, data, a program, or the like that is necessary, for the processor. A part of the memory may further include a non-volatile random access memory (NVRAM). A communication connection to at least one other network element is implemented (in a wired or wireless manner) by using at least one transceiver 2105.

0143In some implementations, the memory 2106 stores a program 21061, and the processor 2102 executes the program 21061, to perform the following operations: <ul id="ul0008" list-style="none" compact="compact"><li>sending a registration request to a registration center, where the registration request includes parameter information of a first service, so that the registration center stores the parameter information of the first service into a service parameter database, where the service parameter database is used to determine a target service corresponding to target parameter information, the target parameter information is parameter information of a service needed by a first device, the target parameter information includes information about an invocation mode and may include at least one of information about a first transmission mode, information about a transmission protocol, and information about a second transmission mode, the information about the first transmission mode is an in-band identifier or an out-of-band identifier, the in-band identifier is used to indicate a transmission mode in which invocation information is added to data for transmission between the first device and the second device, the out-of-band identifier is used to indicate a transmission mode in which the data and the invocation information are separately transmitted between the first device and the second device, the invocation mode is one-request-one-response or one-request-multiple-response, the transmission protocol is any one of a Representational State Transfer Application Programming Interface Protocol, an Advanced Message Queue Interface Protocol, a Message Queuing Telemetry Transport Protocol, and a Remote Procedure Call Protocol, and the second transmission mode is transmitting information between the first device and the second device directly or by using an intermediate node; and</li><li>receiving the invocation information sent by the first device, where the invocation information is used to invoke the target service.</li></ul>

0144It can be learned from the foregoing technical solution provided in this embodiment of this application that, the registration request is sent to the registration center, so that the parameter database of the registration center stores parameter information of a plurality of different services. After receiving a service discovery request, the registration center queries the parameter database for parameter information satisfying a requirement, determines a service corresponding to the parameter information satisfying the requirement, and sends the description information of the service to the first device. In this way, the first device can invoke the service of the second device, and therefore the first device can obtain the service of high quality.

0145An embodiment of this application further provides a computer storage medium, and the computer storage medium may store a program instruction for executing any one of the foregoing methods.

0146Optionally, the storage medium may be specifically the memory 1906, 2006, or 2106.

0147A person of ordinary skill in the art may be aware that, units and algorithm steps in the examples described with reference to the embodiments disclosed in this specification can be implemented by electronic hardware or a combination of computer software and electronic hardware. Whether the functions are performed by hardware or software depends on particular applications and design constraints of the technical solutions. A person skilled in the art may use a different method to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this application.

0148It may be clearly understood by a person skilled in the art that, for the purpose of ease and brevity of description, for detailed working processes of the foregoing system, apparatus, and unit, reference may be made to corresponding processes in the foregoing method embodiments. Details are not described herein again.

0149In the several embodiments provided in this application, it should be understood that the disclosed system, apparatus, and method may be implemented in other manners. For example, the described apparatus embodiments are merely examples. For example, the unit division is merely logical function division and may be other division in actual implementation. For example, a plurality of units or components may be combined or may be integrated into another system, or some features may be ignored or not be performed. In addition, the displayed or discussed mutual couplings or direct couplings or communication connections may be implemented through some interfaces. The indirect couplings or communication connections between the apparatuses or units may be implemented in electrical, mechanical, or other forms. The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, may be located in one position, or may be distributed on a plurality of network units. Some or all of the units may be selected depending on actual requirements, to achieve the objectives of the solutions of the embodiments.

0150In addition, functional units in the embodiments of this application may be integrated into one processing unit, or each of the units may exist alone physically, or at least two units may be integrated into one unit.

0151When the function is implemented in a form of a software functional unit and sold or used as an independent product, the function may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of this application essentially, or the part contributing to the prior art, or some of the technical solutions may be implemented in a form of a software product. The computer software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the steps of the methods in the embodiments of this application. The foregoing storage medium includes any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk, or an optical disc.