The rapid increase in the number of network-enabled devices and sensors deployed in physical environments is changing communication networks. It is predicted that within the next decade billions of devices will generate a myriad of real world data for many applications and services by service providers in a variety of areas such as smart grids, smart homes, e-health, automotive, transport, logistics, and environmental monitoring. The related technologies and solutions that enable integration of real world data and services into the current information networking technologies are often described under the umbrella terms of the Internet of things (IoT) or machine-to-machine (M2M) communications. Because of the large amount of data created by devices there is a need for an efficient way to identify and query this data.
M2M semantic support is intended to enable semantics to the original resources for universal understanding/interpretation of them, as well as any advanced processing on them, e.g., semantic query, data analytics, etc. Introduced in the background section are the existing technologies that are developed in Semantics Web and the existing ontologies that are developed in different namespaces. In addition, the oneM2M architecture and service layer are introduced.
Existing Technologies in Semantics Web
The Semantics Web uses a combination of a schema language and an ontology language to provide the capabilities of ontologies. An ontology uses a predefined, reserved vocabulary to define classes and the relationships between them for a specific area of interest, or more. Resource Description Framework Schema (RDFS) as defined by the World Wide Web Consortium (W3C) (e.g., RDF Vocabulary Description Language 1.0: RDF Schema) provides a specific vocabulary for Resource Description Framework (RDF) that may be used to define classes and properties. The Web Ontology Language (OWL) extends the RDFS vocabulary with additional resources that may be used to build more expressive ontologies for the web.
RDF is a framework for representing information in the Web. RDF is essentially a data-model. Its basic building block is a resource-property-value triple, called a statement. RDF has been given syntax in XML, JSON, etc.
The web ontology language (OWL) extends the RDFS vocabulary with additional resources that may be used to build more expressive ontologies for the web. OWL introduces additional restrictions regarding the structure and contents of RDF documents in order to make processing, reasoning more computationally feasible. For example, OWL defines properties that correspond to the standard set operators: intersection, union, and complement to define Boolean combinations of classes.
OWL uses the RDF and RDFS, XML schema datatypes, and OWL namespaces. The OWL vocabulary itself is defined in the namespace http://www.w3.org/2002/07/owl# and is commonly referred to by the prefix owl. Datatypes represent ranges of data values that are identified using URIs. OWL allows you to use a number of predefined datatypes, most of which are defined in the XML Schema Definition (XSD) namespace. OWL allows a user to define her own datatypes by extending XSD.
Existing Ontologies from Different Namespaces
There are many ontologies that have been developed and shared. They can provide a basis for extension and reuse. There are also a number of ontologies that provide an in-depth representation of a narrowly scoped area of interest. With this kind of ontology, it may not necessarily be extended, rather simply be used directly or generalized. The followings are some examples of such kinds of ontologies that are highly relevant to M2M system.
The Friend of a Friend (FOAF) project maintains the FOAF ontology, which expresses information relevant to sharing information about friends on the World Wide Web. The ontology contains classes and properties for capturing personal information, email addresses, online account and instant messaging information, as well as online documents and images. The goal of the FOAF project is to provide a means to capture the user's online life in an application-independent and website-independent manner in order to break down the walls that divide the various communities on the Web. The examples of common properties defined for an individual (foaf:Person) include foaf:name, foaf:title, foaf:homepage, foaf:interest, and foaf:topic_interest, among others.
The Semantic Sensor Network (SSN) Ontology is developed by the W3C Semantic Sensor Networks Incubator Group (SSN-XG). The SSN ontology describes sensors and observations, and related concepts. SSN ontology model contains the classes and properties that may be used to represent particular aspects of a sensor or its observations, such as sensors, observations, features of interest, the process of sensing (e.g., how a sensor operates and observes), how sensors are deployed or attached to platforms, the measuring capabilities of sensors, as well as their environmental, and survival properties of sensors in particular environments. Examples of classes may include ssn:Sensor, ssn:SensorInput, and ssn:SensorOutput, among others. Examples of properties may include ssn:hasMeasurementCapability, ssn:observationSamplingTime, and ssn:qualityOfObservation, among others. See http://www.w3.org/2005/Incubator/ssn/XGR-ssn-20110628/images/OntStructure-Overview.jpg which is incorporated by reference in its entirety
IEEE 11073 (ISO/IEEE 11073, Health informatics—Medical/health device communication standards) Personal Health Data (PHD) standards are a group of standards addressing the interoperability of personal health devices such as weighing scales, blood pressure monitors, blood glucose monitors, and the like.
IEEE 11073-20601 (IEEE 11073-20601, Health informatics—Personal health device communication—Part 20601: Application profile—Optimized exchange protocol) is the framework standard which defines the generic data types, message types and communication model. This supports any number of (relatively small) “device specialization” standards (such as the IEEE 11073-10415 standard for weight scale) which need only define the data model for that particular type of personal health device.
The IEEE 11073-20601 defines the classes such as medical device systems (MDS) and metric class. For MDS each Agent has one MDS object, which identifies it and reports its status. The attributes of the MDS object identify it to the Manager, represent the time and status, and provide other information. The MDS then contains zero or more of some of the objects represented by the classes below. Metric Class is the base class for all objects representing measurements, status and context data, which also has many subclasses, for example a numeric may represent a single measurement.
oneM2M Service Layer
The oneM2M standard (oneM2M-TS-0001 oneM2M Functional Architecture-V-0.6.1) under development defines a Service Layer called “Common Service Entity (CSE)” as illustrated in
oneM2M architecture enables the application service node (ASN), application dedicated node (ADN), the middle node (MN), and the infrastructure node (IN). The ASN is a node that contains one CSE and contains at least one AE. An example of physical mapping is an ASN residing in an M2M Device. The ADN is a node that contains at least one AE and does not contain a CSE. An example of physical mapping is an ADN residing in a constrained M2M Device. An MN is a node that contains one CSE and contains zero or more AEs. An example of physical mapping for an MN is an MN residing in an M2M Gateway. The IN is a node that contains one CSE and contains zero or more AEs. An example of physical mapping for an IN is the IN residing in an M2M Service Infrastructure.
The M2M Service Architecture described in (Service Component Architecture, TS-0007 Service Component Architecture-V-0.2.0) augments the oneM2M Functional Architecture by specifying M2M Services provided to M2M Application and M2M Service Providers. The components, shown in
As discussed above, there are several existing common foundational ontologies that may be reused by the M2M system. It may not be effective if the M2M system re-defines those common foundational ontologies, which also reduces the interoperability between the M2M system to other systems without re-using the existing foundational ontologies. For example, in a use case discussed in more detail herein, in order to describe the semantics of gym member, devices deployed in the gym, the M2M system may need to have the corresponding ontologies, such as the ontology for describing a person, the ontology for describing sensors, or blood pressure monitor. Without using the existing foundational ones, such as FOAF ontology, SSN ontology, IEEE 11073 personal health data model, the M2M system may re-define those ontologies. It is possible that those ontologies may not be interoperable with the existing ones if they are re-defined, which prevents the M2M system and other systems from understanding each other.
The M2M system may also need to incorporate the ontologies from different verticals such that the ontologies defined by one vertical may be shared and used by other verticals through the M2M Service Layer. The existing M2M systems lack the support of ontology management. The issues include the following issues. A first issue, there is no high level ontology that can model the M2M system with other systems. Such ontology is needed to understand how the M2M system interacts with other systems from the perspective of ontology sharing and re-using. A second issue, there is a lack of mechanisms of how the M2M system may incorporate domain-specific ontologies from different namespaces outside of the M2M system, such that they can be stored, discovered, and re-used by the M2M system. A third issue, there is a lack of mechanisms of how the M2M system can incorporate the ontologies from different verticals inside of M2M system. A fourth issue, there is lack of mechanisms of how the ontologies that are published to the M2M system can be efficiently stored to facilitate the ontology discovery.
Disclosed herein is an M2M Ontology Processor (MOP), which is in charge of processing, storing, or providing discovery function to ontologies either published from outside or inside of the M2M domain. The MOP may functionally consist of an ontology processing component (OPC), an ontology classifying component (OCC), an ontology discovery component (ODC), and an ontology repository (OR). The OPC may process published ontologies external and internal of M2M namespace, which may be used to provide semantics information to objects/entities. The OCC may classify the ontologies and store them in the right hierarchy/location in the Ontology Repository for discovery and usage. The ODC may provide the ontology discovery and determine the matching one(s) for a requester to use. The OR may store any ontology models that are published or generated external and internal to the M2M domain. Those ontologies may be used for resources to enable semantics. Thus, the OR may interact with both OCC and ODC.
The MOP functionalities may also be applicable to other namespaces/systems other than M2M. For example, W3C may also adopt the MOP functionalities to process, classify and store the ontologies published from the M2M namespace.
Disclosed is an oneM2M example of the M2M high level ontology model and MOP, as well as the resource tree example of an OR. The disclosure also discusses oneM2M examples of classes and relationships within ontology resources which facilitate semantic annotations use of multiple ontologies and facilitates reasoning.
This Summary is provided to introduce a selection of concepts in a simplified form that are further described below in the Detailed Description. This Summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. Furthermore, the claimed subject matter is not constrained to limitations that solve any or all disadvantages noted in any part of this disclosure.
A more detailed understanding may be had from the following description, given by way of example in conjunction with the accompanying drawings wherein:
A machine-to-machine (M2M) system may include semantics nodes that house semantics related resources. Semantics related resources of the M2M system may be based on a set of proprietary ontologies. But there are many existing common foundational ontologies that may be reused by the M2M system. Relying on proprietary ontologies may affect the interoperability of M2M systems to other systems. It may be more efficient for the M2M system to use already exiting ontologies, such as Friend of a Friend (FOAF) or Semantic Sensor Network (SSN) ontologies. Within the M2M system there also may be different verticals, such as e-Health, fleet management, or smart homes. These verticals within the M2M system may have different ontologies as well. Disclosed herein is an ontology processor and other mechanisms for addressing the management and interoperability of ontologies. The ontology processor may reside on one or more semantics nodes of a M2M system, for example.
A brief summary of semantics node architecture is presented below to give context with regard to the ontology processor, which may reside with a semantics node. More details with regard to semantics node architecture are provided in the descriptions corresponding to
In conventional machine-to-machine (M2M) systems, M2M applications (hosted on end devices as well as backend network servers) need to agree beforehand on a common definition of exchanged data. This is primarily due to a lack of semantic aware M2M service layers that are able to parse, interpret or process M2M data on behalf of applications. In current M2M systems, M2M service layers lack semantic awareness capabilities and hence data flowing through or stored within M2M service layers is treated as opaque information.
This lack of semantic awareness prevents M2M service layers from offering services which allow data produced by M2M applications to be effectively abstracted or virtualized by the M2M service layer such that it can be discovered, accessed, interpreted, and shared by different applications even if they do not have any prior knowledge of the application from which the data originated. As a result, the physical entities that are sensed and acted upon (e.g., appliances, people, cars, rooms of a building, etc.) may not be effectively virtualized/abstracted by M2M service layers and the physical entities are treated as generic entities, intrinsic to the environment, and not tied to a specific M2M application. In order to overcome this limitation, the data transmitted in M2M systems may be associated and integrated with semantic information, such that semantic aware M2M service layers can have the same knowledge of the data as M2M applications. In doing so, M2M service layers can better facilitate the sharing of data across applications and provide value-added semantic aware services to M2M applications (e.g., data aggregation, data sharing amongst different applications, etc.).
For example, in a patient monitoring application illustrated in
Semantics nodes may provide the following functionalities in an M2M system to support M2M service layer semantic awareness and data abstraction: (i) support for storing semantics related resources, and/or support for interfaces to servers storing semantics related resources; (ii) support for mechanisms for creating, retrieving, updating, and deleting semantics related resources; and (iii) capabilities to publish and discover semantics related resources.
As described herein, a semantics node is a logical entity that may be hosted on a stand-alone computing device (e.g., server) in the network or hosted on an existing entity within the network, such as an M2M gateway, M2M device, M2M server, or the like. A semantics node may be seen as a repository that stores semantics-related resources modeling. For example, a sensor device for blood pressure may want to understand how to describe its data, so it queries a nearby semantics node to find out if there is a blood pressure class already defined. If so, the semantics node responds to the sensor device with the blood pressure class it found locally. If not, the semantics node may query other semantics nodes (e.g., siblings or parents). The use of a semantics node may reduce the need to have end devices store models of data.
A semantics node stores and manages semantics related resources. Semantics related resources usually describe other resources, such as, for example, the ETSI M2M resources that are stored under the resource tree, <SCL>, <application>, <container>, <contentInstance>, which need to have semantics related resources associated with them in order to enable an understanding of their semantics. In one example, semantics related resources may have one of three types: class, relationship, and term. This categorization provides compatibility with current techniques of the semantics web and enables an M2M system to leverage existing semantics related resources. There is a mix of ETSI and oneM2M based examples herein. One skilled in the art will be able to understand that ETSI and oneM2M have similar resource tree structures and should be able to relay the concepts herein in either one.
As discussed herein, semantics nodes may be deployed in an M2M system in different levels, such as a M2M area network, a M2M access network, and a M2M core network, such that the different levels form into a hierarchical structure. Semantics nodes in the same level may be distributed and have a sibling relationship. Mechanisms are disclosed with regard to building and maintaining such a hybrid architecture of semantics nodes, which provides the benefits of different levels of abstraction and compatibility to an existing network hierarchy.
It is understood that the entities performing the steps illustrated herein (e.g.,
For additional perspective,
In order to provide the semantics to the devices of
With continued reference to
The ontology publishing message may include one or more fields as summarized in Table 1, such as a namespace, name, compatibility, access_right, topic, relevance, or ontology representation. The fields of Table 1 may be used for messages associated with external namespaces (e.g., non-M2M namespace 738) or associated with M2M verticals (e.g., M2M verticals e-health and smart home on node 728 and node 737) that have their ontologies published to OPC 726. The published ontologies may be an update of previously published ontologies to OPC 726.
With reference to Table 1, the namespace field indicates the namespace of the published ontology. The name field indicates the name of the published ontology. The compatibility field indicates whether the ontology representation contained in the ontology publishing message body is compatible with the ontology representation chosen by an M2M system 735 having an M2M namespace (e.g. M2M namespace 735). To simplify examples discussed herein with regard to ontology management, it will be assumed that the M2M system 721 is equivalently encompassed by the M2M namespace 735, as shown in
With continued reference to Table 1, the access right indicates how the ontology may be accessed by other parties and entities. The access right may be different for different parties (e.g., individuals, businesses, governments, or other parties) with different relationships with the ontology publisher. The accessRight field may look like Table 2. The sub-field operation shows the permitted operation, such as RO (read only), RW (read and write), etc. The sub-field party shows the corresponding party/parties that are allowed to carry out the operation on the published ontology, which could be public (e.g., every party can have the operation on it), the parties with certain relationship with the publisher, individual parties, etc. Table 2 shows a few examples, every public party is able to have the read access to the published ontology, while only the applications with the same owner as the publisher (the publisher could be another application) can have the read and write access to the published ontology.
With further reference to Table 1, topic designates the topic the ontology is relevant to. The topic field may contain one or more key words to describe the ontology. For example, when the FOAF ontology is published, the topic filed could be “person.” The topic may come from a well-known/commonly-used vocabulary that is understood by all namespaces and may be standardized as well. This field may also be left blank, thus OCC 724 may decide the relevant topic for the published ontology, which is discussed in more detail below. Relevance, as shown in Table 1, indicates whether the published ontology has any relevance to other ontologies. For example, the published ontology may be extended or revised from the existing ontologies stored in OR 727. For example, FoAF ontology may be extended to include more attributes of a person other than those that are already defined. Ontology representation, as shown in Table 1, contains the representation of the published ontology. In some instances, the publisher may only publish the URI of the ontology. If ontology representation is in the non-M2M-compliant format, the schema of the ontology may be included.
As briefly discussed above, ontologies may be from outside namespaces (non-M2M namespaces) or an inside namespace (e.g., oneM2M namespace). With reference to
With continued reference to
With continued reference to
With further reference to
Table 3 shows a publishing message that may be from an FOAF_Project namespace with an FOAF ontology. The namespace field is set to “FOAF_Project: http://xmlns.com/foaf/0.1/”. The name field is set to FOAF. FOAF ontology is also written in RDF/OWL, thus the compatibility field is set to Y. The accessRight is set to be Public (FOAF is open to the public). The topic field is set to be “person.” The ontology representation's URL is contained in the message body, from which MOP 721 is able to download and obtain the ontology.
Table 4 shows the publishing message from a SSN_Project namespace with an SSN ontology. The namespace field is set to “SSN_Project: http://purl.oclc.org/NET/ssnx/ssn.” The name field is to SSN. SSN ontology is also written in RDF/OWL, thus the compatibility field is set to Y. The accessRight is set to be Public (SSN is open to the public). The topic field is set to be “sensor”. The ontology representation's URL is contained in the message body, from which MOP 721 is able to download and obtain the ontology.
Table 5 shows the publishing message from the IEEE 11073 namespace of the weight scale's data ontology. The namespace field is set to IEEE 11073. The name is set to “scale: IEEE 11073-10415”. The publisher publishes the ontology in a schema that is different from RDF/OWL. Thus the compatibility field is set to N. OPC 726 needs to take care of converting the ontology to the compatible format. The resulted ontology is discussed in more detail below with regard to Table 9. The accessRight is set to IEEE member (only IEEE members are able to access the specification of IEEE 11073-10415). Later if a requester wants to access this ontology, MOP 721 needs to check with an IEEE endpoint or application to validate the membership of the requester. The topic field is set to be “health”. The ontology representation is contained in the message body, which contains the schema of the ontology followed by value of each field.
Table 6 shows the publishing message from the IEEE 11073 namespace of the blood pressure monitor's data ontology. The namespace field is set to IEEE 11073. The name is set to “BPMonitor: IEEE 11073-10407”. The publisher publishes the ontology in the compatible format that the M2M system 739 adopts. Thus the compatibility field is set to Y. The accessRight is set to IEEE member (only IEEE members are able to access the specification of IEEE 11073-10407). The topic field is set to be “health”. The ontology representation is contained in the message body, which follows the patterns used in XSD to describe the simple and complex data types.
Table 7 shows the publishing message from an M2M vertical (e.g., eHealth) of the blood pressure (BP) ontology. The namespace field is set to M2M. The compatibility field is set to Y, because the vertical follows the M2M compliant format in representing the ontology. The topic field is left blank. The ontology representation is contained in the message body, which follows the patterns used in XSD to describe the simple and complex data types.
With further reference to
As discussed briefly above, for the ontology that is represented in a format not compatible with the M2M domain (e.g., Table 5), OPC 726 may convert the ontology to the compatible format. For example, if all the ontologies inside the M2M namespace are represented by OWL, those ontologies represented in other formats are considered to be not compatible within the M2M namespace.
With reference to
OCC 724 classifies the ontology and locates the right hierarchy to store it. The classification includes deciding whether the ontology belongs to a non-M2M namespace (e.g. non-M2M namespace 738) or M2M namespace (e.g., M2M namespace 735), which namespace it belongs to, which topic it belongs to, etc. OCC 724 interprets the published ontology and extracts the fundamentals of the ontology. The fundamentals include the classes and properties that are contained in the ontology. Each of the classes and properties can be incorporated into the M2M system, which will be stored in the Ontology Repository (OR) 727.
OR 727 stores the ontologies in a structure that may simplify discovery. An exemplary structural architecture is shown in
With continued reference to
The following discussion uses one or more of the examples of the published ontologies described with regard to Tables 3-Table 7, to discuss the processing of OCC 724, storing in OR 727, and the corresponding content in each level of OR 727.
With continued reference to
With continued reference to
With reference to
Exemplary fields and descriptions in a discovery request message may include a request type, a search key, or a response type. Table 10 shows a summary of the fields. The request type indicates what the requester is looking for, which could be an entire ontology, or fundamentals inside of an ontology. Thus the possible value of this field may be the following: ontology, class, relationship. The search key includes the search keys sent by the requester. Note, the ontologies may also have their own semantics (e.g. namespace or topic they belong to), which are maintained by a semantics Repository in
At step 773, ODC 723 of MOP 721 analyzes the request, and searches over OR 727 for M2M namespace 735 at the topic level. ODC 723 finds the possible matching topic is health. ODC 723 further searches over the ontologies under the health topic, and finds two matching ontologies. One is virtual, which contains the URI of the original ontology: Non-M2M-Namespace/IEEE11073/11407/. Another is with URI of M2M-Namespace/health/bloodPressure/. ODC 723 eventually finds the two matching classes under the two ontologies and, at step 774, returns the URI of them to requester 771. At step 775, requester 771 may retrieve the representations of the two ontologies, and see if any of them is suitable for describing its data. The requester 771 may also extend any of the existing ones to suit its own data. For example, Table 6 shows the ontology published by IEEE 11073-10407, it has 4 elements. Table 7 shows the ontology published by M2M vertical, which has 2 elements. The client may have data that only has two elements that needs to be described. So the ontology in Table 7 will be the suitable ontology.
With reference to the gym use case associated with
In order to provide the semantics to those devices and their measured data, each device may need to discover the ontology satisfying its own requirement and use it. On the other hand, the members of the gym also need ontology to describe their profiles and relationships to each other. The followings show how the published ontologies maintained by OR 727 may be discovered and used in the gym use case, such that they do not need to be re-created by the M2M namespace again.
A phone of a gym member 707 (hereinafter gym member) may send a discovery request (containing class, person, URI in the message) to MOP 721 to find the ontology to describe his/her profile and relationship to others, the MOP may match the FOAF ontology under the person topic to this request and return the URI of the ontology to the gym member 707. In order to use it, the gym member 707 retrieves the ontology representation from OR 727 by targeting the URI.
An application of an ambient sensor 706 may send a discovery request (containing class, sensor, URI in the message) to MOP 721 to find the ontology to describe its measured data, the MOP 721 can match the SSN ontology under the sensor topic to this request and return the URI of the ontology to the sensor. In order to use it, the ambient sensor 706 retrieves the ontology representation from OR 727 by targeting the URI. Note, since the ambient sensor 706 is resource constrained device, it may not have the ability to process the whole representation of the SSN ontology. The ambient sensor 706 may further discover the fundamentals of the ontology from the URI, and only retrieve the one(s) it needs, (e.g., ssn:SensorOutput).
An application of a blood pressure monitor 701 may send a discovery request (containing class, health; blood pressure, URI in the message) to MOP 721 to find the ontology to describe its measured data, the MOP 721 may match the two ontologies under the health topic to this request and return the URIs of the ontologies to the application of the blood pressure monitor 701. In order to use one of them, the application of the blood pressure monitor 701 retrieves the ontology representation from OR 727 by targeting the URI.
An application of weighing scale 702 may send a discovery request (containing class, health; scale, URI in the message) to MOP 721 to find the ontology to describe its measured data, the MOP 721 may match the ontology under the health topic to this request and return the URI of the ontology to the application of weighing scale 702. In order to use it, the application of weighing scale 702 retrieves the ontology representation from OR 727 by targeting the URI. It is possible that one of the devices, such as the ambient sensor 706, gym member 707, application of blood pressure monitor 701, and application of weighting scale 702, may not be satisfied with the ontologies discovered and retrieved from OR 727. The devices may extend or modify the ontologies per their requirements.
Below is a discussion of a particular example that may be applicable to oneM2M. oneM2M defines the capabilities supported by the oneM2M Service Layer. The oneM2M Service Layer is instantiated as a Common Services Entity (CSE) which comprises a set of Common Service Functions (CSF). In one example, the MOP 721 may be hosted in a CSE as an oneM2M CSF as shown in
Any oneM2M verticals, i.e. AEs, may talk to the Ontology Management CSF via the Mca reference point to publish their ontologies or discover the existing ontologies, or other CSEs may talk to the Ontology Management CSF via the Mcc/Mcc′ reference point to publish their ontologies or discover the existing ontologies. The publishers from outside of oneM2M namespace may talk to the Ontology Management CSF via the Mcc′ reference point to publish their ontologies. As a result, the corresponding messages and procedures proposed discussed herein with regard to the MOP will apply to Mca, Mcc and Mcc′ reference points.
An exemplary oneM2M based resource tree structure of Ontology Repository (OR) is shown in
In addition,
Discussed below with reference to
A second consideration of the resource structure for the <class> and <relationship> resources are shown in
The second embodiment of the <class> and <relationship> resources (
M2M system (e.g., oneM2M) may also publish an M2M ontology to other namespaces/systems (e.g., W3C) that may also adopt the MOP functionalities to process, classify and store ontologies. The message flow shown in
M2M High Level Ontology Model
Functional Architecture of M2M Semantic Support
Below is further discussion with regard to ontologies to give further perspective. All things in the physical world may be considered as physical objects. Each of the physical objects may be modeled as an abstract object in different namespaces.
With regard to the gym use case as discussed regarding
As further shown, a network domain, such as network domain 122, may further comprise one or more devices, such as device 145 (which for example may be one of the M2M devices used in the patient monitoring application of
Still referring to
Typically, the device 145, gateway 140, and M2M server platform 125 comprise computing devices, such as the devices illustrated in
As further shown in
I. M2M Architecture with Semantics Nodes
One example of a M2M system that includes semantics nodes is illustrated in in
As shown in system 150, application 158 may be communicatively connected with M2M semantics node 160 located in area network 157 via reference point sIc 159. The sIc reference point is generally used by applications, other non-semantics node entities in the area network, access network, and core network entities to talk to a semantics node. M2M semantics node 160 is communicatively connected with external semantics node 163 via reference point sIe 162. The semantics nodes in M2M systems may interface with external semantics nodes via the sIe reference point. The external semantics nodes may manage other existing semantics related resources such as those defined by RDFS for the semantics web. M2M semantics node 160 is also communicatively connected with M2M semantics node 164 located in access network 153 via sIs reference point 161. M2M semantics node 164 is communicatively connected with M2M gateway 165 via sIc reference point 166 and communicatively connected with M2M semantics node 168 located in core network 151 via reference point sIs. In this example, the M2M Gateway 165 itself is not a semantics node, but in other examples, the M2M Gateway 165 could incorporate the functionality of semantics node.
Semantics node(s) may be deployed at the area level for the purpose of offloading, load balancing, easy access, etc. At the area level, it is possible that there is no semantics node deployed if all the devices in the local area network communicate with a semantics node in the attached access or core networks. A semantics node at the area level may have a corresponding parent semantics node at the access level (e.g., M2M semantics node 160 connected with M2M semantics node 164) or at the core level (e.g., M2M semantics node 169 connected with M2M server 170 that includes a semantics node). Semantics nodes talk to each other through the sIs reference point. The details of the reference points are defined further hereinafter. A semantics node at the access level may also have a parent at the core level, which it communicates with over the sIs reference point. Likewise, a semantics node at the access level may have children semantics nodes at the area level, which it communicates with via the sIs reference point. Semantics nodes at the core level may also have children semantics nodes at the access or area level.
In addition to the parent-child relationships illustrated in
For a constrained device, due to the limit of capacity, the semantics can be a code referring to a specific semantic or a link pointing to the semantics stored in a remote semantics node. Such semantic information may be provided by the application that created the data or by the service layer.
At the access level, there might be one or more semantics nodes deployed in one access network. If so, the siblings may communicate with each other for semantics information notification, broadcast and discovery through the sIs reference point. A semantics node at the access level may also have a parent at the core level which it communicates with over the sIs reference point. Likewise, a semantics node at the access level may have children semantic nodes at the area level which it communicates with via the sIs reference point.
At the core level, there might be one or more semantics nodes deployed in the core network. These nodes may be siblings and communicate with each other over sIs reference point for sharing semantics information using notification, broadcast and discovery. Semantics nodes at the core level may also have children semantic nodes at the access or area level. Applications, other non-semantics-node entities in the area network, access network and core network talk to a semantics node via the sIc reference point.
As mentioned above, a semantics node may be a standalone physical node in a network (e.g., standalone M2M semantics node 160) or it can be a logical entity hosted on another physical node in the network, such as an M2M device 171, M2M gateway 172, or M2M server 170, as shown in system 150 of
A feature of the multi-layer semantics node hierarchy illustrated in
II. Semantics Node Architecture
More details regarding the architecture of a semantics node will now be discussed. As mentioned, a semantics node stores and manages semantics related resources. As defined herein, a semantics related resource comprises information that can be used to describe the semantics information of a thing, such as the meaning of data generated by an M2M device or application or the M2M device or application itself In one example, semantics related resources may be expressed in extensible markup language (XML) using existing schemas, such as XML Schema Definition (XSD), RDF Schema/Web Ontology Language (RDFS/OWL), or the like. In an example, three types of semantics related resources may be stored in a semantics node—classes, relationships, and terms—each of which is described more fully below. The categorization of semantics related resources in this manner provides compatibility with the current techniques of the semantics web. This compatibility enables an M2M system to leverage existing semantics related resources, such as for example those core classes and core properties defined by W3C. Applications and entities external to the M2M system are able to use the semantics related resources hosted by the semantics node, without incurring any extra overhead due to format conversion or modification necessary to make the semantics compatible.
Classes. Discussed herein is the concept of classes of objects/things in an M2M domain. In the example health monitoring system of
Here, the class contains the fields “description,” “unit,” and “base,” and the information in those fields is “temperature in Celsius,” “Celsius,” and “integer,” respectfully. As another example, a BloodPressure class may contain two fields, one for systolic pressure and another for diastolic pressure. The class description for this BloodPressure class would include both fields' descriptions and may be expressed using XML/XSD as follows:
Again, however, it is understood that classes (and the other types of semantic related resources—relationships and terms) are not limited to expression using XML/XSD but rather may be expressed in any of a variety of suitable description languages, including, for example, RDFS/OWL and the like. Classes may also be related to each other. For example, “blood pressure” may be a subclass of “vitals”, or equivalently, “vitals” may be a superclass of “blood pressure.” The subclass/superclass relationships define a hierarchy of classes. In general, A is a subclass of B if every instance of A is also an instance of B. A class may have multiple super classes.
Relationships. Relationships are a special kind of semantics related resource. Relationships describe relations between semantics related resources, for example “created by,” “lifetime,” “subscribed by,” and so on. A relationship can also be identified by a URI/URL, which gives a global and unique naming scheme to relationships of the M2M domain. Classes and inheritance are known in other fields of computing, for example in object-oriented programming. But while there are similarities, differences exist too. In object-oriented programming, an object class defines the relationships or properties that apply to it. To add new relationships or properties to a class means to modify the class. However, here, relationships are defined globally, that is, they are not encapsulated as attributes in class definitions. A new relationship may be defined that applies to an existing class without changing the definition of the class itself. Like classes, the relationships can also be related to each other. For example, “energy mode” and “usage mode” are sub-relationships of “mode”. If a device has an “energy mode” of electric and a “usage mode” of manual, then it has a “mode” of electric and manual.
Terms. Terms are concepts that are commonly used in an M2M domain. As defined herein, a term is a value that may be used by many parties to describe the semantics of a resource. The definition of a term may be universally acknowledged in certain domains where it is published. For example, manual, user-directed, and autonomous are each examples of terms that may be used to describe, for example, an appliance's usage mode. In general, the creator of a semantics related resource will determine whether that semantics related resource is a class, relationship, or term. A semantics node will then store the semantics related resources under the categories defined or determined by their creator. For example, in the patient monitoring example of
The semantics of a resource (including data, thing, etc.) can be described by a resource-relationship-value triple, consisting of a resource, a relationship and a value. Values can either be classes, terms, or other resources. The following are some examples,
Through the proposed sIc, sIs and sIe reference points, requests to a semantics node's class, relationship and term resources can be made.
III. M2M Semantics Node Functions and Reference Points
In this section, further details concerning the functions and reference points of a semantics node are provided. In one example, a semantics node may perform the following functions: authenticating other semantics nodes including authenticating lower level children or parallel sibling semantics nodes in a semantic node hierarchy to allow them to register and make requests for a semantic node's resources; authenticating applications, devices, and/or users to allow them to publish, create, delete, update, and retrieve semantics related classes, relationships and terms resources; storing and managing semantics related classes, relationships and terms resources; providing support for discovery of semantics related resources; and providing support for semantics nodes to communicate with one another (between parent-child, siblings) in order to collaborate on discovery queries and share semantics related resource information.
A semantics node may communicate with other entities in the network via one or more reference points or interfaces. In one example, three reference points are defined—a sIs reference point, a sIc reference point, and sIe reference point. The sIs reference point is used for communication between semantics nodes. The sIs reference point may also be used by a semantics node to register to another semantics node to form parent-child or sibling relationships, to discover other semantics nodes, to notify others about its status (e.g., online, offline, overloaded, etc.), to trigger another semantics node to perform a particular operation (e.g., de-registration, registration), to publish, create, delete, update, and retrieve semantics related resources in another semantics node. In addition, a semantics node may use the sIs reference point to subscribe to semantics related resources in another semantics node and to receive corresponding notifications, to discover semantics related resources on the siblings and parent semantic nodes in its hierarchy, to move a group of semantics related resources from one semantics node to another semantics node, and to allow the semantics related resources stored in another semantics node to be linked and associated with a resource to provide the semantics to that resource, as described further below in connection with
In the present example, the sIc reference point may be used by an application or non-semantics node to communicate with a semantics node from various network domains (e.g., area network, access network, or core network). The sIc reference point also allows an application or non-semantics node to publish, create, delete, update, retrieve, subscribe to, or discover semantics related resources in a semantics node and to receive notifications from the semantics node. In addition, the sIc reference point allows the semantics related resources stored in a semantics node to be linked and associated with a resource to provide the semantics to that resource.
The sIe reference point may be used for communication between a semantics node that is part of an existing hierarchy of nodes in an M2M system and an external semantics node. An external semantics node stores semantics-related resources outside of the M2M domain. One example of an external semantics node may be a server that stores the semantics-related resources for Semantic Sensor Network Ontology that is defined by the W2C Semantic Sensor Network Incubator Group, as described at http://www.w3.org/2005/Incubator/ssn. The sIe reference point allows a semantics node to retrieve, discover, and subscribe to semantics related resources in an external semantics node and vice versa. Also via the sIe reference point, external semantics nodes may discover semantics nodes in the M2M system and receive notifications.
One example of the messages associated with the sIs, sIe, and sIc reference points, which effectively define those reference points, are set forth below in Table 16.
Table 16 lists semantics node related messages, there corresponding meanings, and reference points used.
Protocols such as hypertext transfer protocol (HTTP) or constrained application protocol (CoAP) may be used as an underlying transport protocol for carrying the different types of messages. Examples are presented below of the use of these messages to perform the various semantic node functionalities discussed above
IV. M2M Semantics Node Procedures
A. Build Semantics Node Hierarchy
In this section, additional details are provided regarding how a hierarchy of semantics nodes (hereinafter “semantics node hierarchy”) may be built, in accordance with one example. In this example, a semantics node hierarchy is built up by determining the parent-child and sibling relations between the semantics nodes located at the different area, access, and core levels in a network.
The discovery of sibling semantics nodes may be based on sending out semantics node discovery requests (e.g., multicast, broadcast, anycast) where a discovery request can be issued in an attempt to discover sibling semantics nodes. The request can have a defined hop-limit that limits the flooding of discovery request and response messages, which may congest the network. Alternatively, the discovery can leverage existing discovery mechanisms available within the network, such as domain name system (DNS), DNS service discovery (DNS-SD), service location protocol (SLP), etc., if available. A semantics node may store the returned information of the neighboring sibling semantics nodes, such as IP address or type(s) of semantics information managed. As discussed further below, the sibling semantics node discovery response message may also piggyback the address of a higher-level semantics node discovery server, the address of a parent semantics node of the sibling, or both.
Referring still to
In the present example, at each level, there may be one semantics node discovery server, which accepts a higher-level semantics node discovery request by default. The address of the semantics node discovery server may be well known to the lower level semantics nodes. As shown in
If the new semantics node is provisioned with the upper level semantics node discovery server's address, it can perform the semantics node discovery directly (control passes from step 604 to step 614). Otherwise, it decides whether it wants to choose from the siblings' parent list and whether it wants to retrieve the default semantics node discovery server's address from siblings (steps 608 and 610). If the new semantics node chooses an upper-level semantics node from the siblings' parents (step 618), it may choose not to perform the semantics node discovery further. Otherwise, it decides the criteria of choosing the parent (nearest in hop count, supporting the same type(s) of semantics resources, etc.) (step 614). Based on the criteria, it sets up the information it wants to discover in addition to the semantics nodes' addresses in the upper level (distance, supported type(s) of semantics resources, etc.) (step 616).
At step 620, the new semantic node may register to the higher level parent semantics node it discovered or otherwise selected. If the new semantic node is unable neither to learn the address of a higher-level semantic node discovery server nor to identify any higher-level parent semantic nodes of its siblings to which it might register, it may determine that no higher level parent semantic nodes are available and end the process at step 612.
Referring back to
Semantics node discovery server 183 may be considered a centralized point for storing information of the semantics nodes scattered in the same level or a rendezvous point to flood the discovery request in the same level of a network and collect the returned responses of semantics nodes. Semantics node discovery server 183 may be a server that resides in a network at a higher, same, or lower level network level than the network level of new semantics node 181. This example assumes that semantics node discovery server 183 is in an upper level in relation to the network level of new semantics node 181. The address of the semantics node discovery server 183 can be well known to lower level semantics nodes (e.g., sibling semantics node 182). If new semantics node 181 is not provisioned with semantics node discovery server 183, then new semantics node 181 may perform sibling semantics node discovery. If new semantics node 181 is provisioned with the address of the semantics node discovery server 183, it can perform the semantics node discovery directly.
At step 186 of
At step 187, new semantics node 181 extracts the received address of semantics node discovery server 183. At step 188, new semantics node 181 sends a semantics node discovery request to semantics node discovery server 183. The request at step 188 may be a query for one or more parent semantics nodes that new semantics node 181 may connect with. At step 189, semantics node discovery server 183 sends a semantics node discovery response to new semantics node 181. The response at step 189 may contain one or more parent semantics nodes. At step 190, new semantics node 181 chooses one parent semantics node to register with. At step 191, semantics node 181 sends a request for registration with its chosen parent semantics node 184. At step 192, parent semantics node 184 sends a response to the request for registration at step 191.
Generally, if new semantics node 181 is provisioned with the address of semantics node discovery server 183, it can perform the semantics node discovery directly. Otherwise new semantics node 181 decides whether it wants to choose from the list of parent semantics node received from one or more siblings and whether it wants to retrieve the default address of semantics node discovery server 183 from siblings. At each level, there may be one or more semantics node discovery servers, which accepts the higher-level semantics node discovery request by default. If new semantics node 181 chooses an upper-level semantics node from the siblings' parents, new semantics node 181 may choose not to perform the semantics node discovery further. New semantics node 181 may have the option to decide the criteria of choosing the parent (e.g., choosing from options, such as nearest in hop count, supporting the same type(s) of semantics related resources, etc.). Based on the criteria, new semantics node 181 sets up the information it wants to discover in addition to the addresses of semantics nodes in the upper level (e.g., distance, supported type(s) of semantics related resources, etc.).
At step 206, semantics node 201 sends a de-register request to current parent semantics node 203, which includes a request to end the parent-child relationship. At step 207, semantics node 201 may receive a response to the de-register request sent in step 206 from current parent semantics node 203 or another device that is able to communicate a perceived status of current parent semantics node 203. Similar to the steps illustrated with regard to
In an example (not shown, but with reference to elements in
Generally, parent-child relationships of semantics nodes are terminated by de-registering to the current parent semantics node when the child semantics node goes offline or when the child semantics node registers to another higher level parent semantics node.
If a neighboring sibling semantics node joins a network, the corresponding sibling information is updated by adding the new semantics node. If a neighboring sibling semantics node leaves a network, the corresponding sibling information is updated by deleting the semantics node or otherwise updating a table to indicate the status of the sibling semantics node that left the network (e.g., status=offline). A semantics node may broadcast or otherwise communicate its status to sibling semantics nodes using, for example, the SEMANTICS_NODE_STATUS_NOTIFY( ) message shown above in Table 14. The status update may affect how a sibling and parent-child relationships are maintained.
B. Semantics Related Resource Discovery, Retrieval, and Validation
An application, a device, a user, a peer semantics node, an external semantics node, or a non-semantics node may send semantics related resource discovery requests to a semantics node through the sIc, sIs, and sIe reference points. The discovery request message may include the type of the semantics related resource (class, relationship, or term) and search string(s). For example, assume a temperature sensing application (App1) in an M2M system that needs to report its temperature reading data—as an integer in units of Celsius—to its M2M gateway. In order to enable the gateway service capability layer (GSCL) to understand the data, App1 needs to associate the data with proper semantics information. In accordance with the procedures described herein, App1 may discover a semantic node that stores a semantic related resource class—the temperatureReading class—that represents temperature data as an integer in units of Celsius. After discovery, App1 will retrieve the representation of the temperatureReading class, and validate that it is the one it wants to use to provide semantics for its temperature data. It will then link the data with the temperatureReading class as one of its attributes (semantics attribute). In the GSCL, the data may be stored under a <tempData> container for App1, which will have a semantics attribute that links to the temperatureReading class using a hasType relationship—as illustrated for example in
If there is not a matching semantics related resource found locally, the semantics node will try to find a matching semantics related resource from its sibling semantics nodes. As indicated by block 226 and block 227, the semantics node forwards the discovery request to the siblings and sets up a time window it will wait for the response to come back. At block 228, it is determined whether a matching semantics related resource is found from the contacted siblings. If matching semantics related resources are returned from its siblings, the corresponding address (e.g., URI/URL) of the semantics related resource(s) is sent back to the issuer with a successful discovery response (block 225).
If there are no matching semantics related resources returned from siblings of the semantics node, then it is determined whether a parent semantics node can be contacted, as indicated by block 229. If there is no parent semantics node, then a discovery response indicating a negative outcome will be returned to the issuer (block 233). If there is a parent semantics node, the semantics node will try to find a matching semantics related resource from its parent semantics nodes. As indicated by block 230 and block 231, respectively, the semantics node forwards the discovery request to the parent semantics node and sets up a time window it will wait for the response to come back. At block 232, it is determined if a matching semantics related resource is found from the contacted parent. If matching semantics related resources are returned from the contacted parent, the corresponding address (e.g., URI/URL) of the semantics related resources is sent back to the issuer with a successful discovery response (block 225). If there are no matching semantics related resources returned from the parent of the semantics node, then a discovery response indicating a negative outcome will be returned to the issuer (block 233).
After the issuer receives a successful discovery response, which contains the address (e.g. URL/URI) of the matching semantics resource, the issuer can retrieve the representation of the semantics resource.
In one example, the semantics node may support a RESTful architecture style (representational state transfer), which consist of clients and servers. Clients (e.g., Issuers) initiate semantic requests to servers (e.g., semantics nodes). In this example, servers (e.g., semantics nodes) process requests for semantics and return appropriate semantic responses. Requests and responses are built around the transfer of representations of semantics related resources. A client can be an application, a user, a device, a semantics node, etc., which can request RESTful operations on the semantics related resources (e.g., classes, relationships, or terms) to a semantics node.
When handling resources in a RESTful architecture, there are four basic methods that may be applied to the semantic related resources:
CREATE: Create a class, relationship, or term resource.
RETRIEVE: Read the content of a class, relationship, or term resource.
UPDATE: Write the content of a class, relationship, or term resource.
DELETE: Delete a class, relationship, or term resource.
A semantics node acting as a RESTful server may validate a received request. The operation is allowed, if the issuer is authorized with the proper access rights.
At step 244, semantics node 242 acts as a server and validates and otherwise processes the received request. The received request is allowed, if issuer 241 is authorized with the proper access rights. If the create operation is allowed by the semantics node 242, the new semantics related resource is created under the proper resource pool based on whether it is a class, relationship, or term. And the semantics related resource is assigned a unique identity or address by semantics node 242. If the update operation is allowed by semantics node 242, the representation of the semantics related resource is updated. If the retrieve operation is allowed by semantics node 242, the representation of the semantics related resource is prepared in the format issuer 241 requests. If the delete operation is allowed by semantics node 242, the requested semantics related resource is deleted.
At step 245, semantics node 242 returns a response to issuer 241. For a create operation, the identity or address of the newly created semantics related resource is returned to the issuer. For an update operation, a response code is returned to issuer 241 whether the operation is successful or not. For a retrieve operation, the representation of the semantics related resource in a format issuer 241 requests are returned to issuer 241. For a delete operation, a response code is returned to issuer 241 to indicate whether the operation is successful or not.
At step 257, semantics node 252 then sends a semantics related resource discovery response back to the Issuer 251, which includes the address (e.g., URI/URL) of the semantics related resource(s) from the parent semantics node 254 that matched the Issuer's request. At step 259, issuer 251 sends a semantics related resource retrieve request based on the received URL. At step 260, parent semantics node 254 sends a semantics related resource retrieve response that contains the requested semantics information which may include a class, relationship, or term.
At step 261, issuer 251 checks (validates) the representation of the received semantics information from step 260. There is a possibility that the received semantics related resource sent at step 260 is not exactly what issuer 251 wants. For example, if issuer 251 requested a temperature class and the returned matching resource is a class called temperatureReading with an associated unit of Fahrenheit, but issuer 251 desires a temperature class with unit of Celsius, then issuer 251 can request that parent semantics node 254 modify the semantics. This can be supported by sending a semantics related resource modify request at step 262 to parent semantics node 254 to modify the semantics related resource. At step 263, the address (e.g., URL/URI) of the newly added or modified semantics related resource will be returned to issuer 251.
With reference to modification of semantics related resources, generally, the semantics node may collaborate with its siblings or parent to perform the modification, if the semantics node does not support modification itself. If the semantics node supports modification, then the semantics node may modify the class locally by adding a new class or extending the current one.
C. Subscribing to Semantics Related Resources
In one example, a semantics node can support a client (e.g., an application, another semantics node, a device, a user, or the like) subscribing to it. As one example, a client may subscribe to the semantic node to be notified when any update to a subscribed semantic related resource. When an update occurs, the subscribing client will be notified with the new representation of the resource. In the case of a client that is a semantic node itself, the subscribed semantics related resource might be stored in another semantics node that the subscriber semantics node has no relation with (e.g., not a parent-child or sibling). In this example, a client may issue a SEMANTICS_RESOURCE_SUBSCRIBE_REQ message to a semantics node. The message identifies the semantics related resource for which the client wishes to receive notifications when the resource is updated. The semantics node will respond to the request with a SEMANTICS_RESOURCE_SUBSCRIBE_RESP message acknowledging the subscription. When the semantics related resource to which the client has subscribed is updated, the semantics node will send a SEMANTICS_RESOURCE_SUBSCRIBER_NOTIFY message to notify the client of the update.
As another example, a semantics node may be interested in being updated with the semantics related resources stored and managed by one of its sibling, parent, or child semantics nodes.
At step 274, semantics node 271 sends a semantics node resource subscribe request to the target semantics node 272. At step 275, the target semantics node 272 determines whether to accept the semantics subscription request of step 274 to the target semantics node 272 can decide whether to accept a subscription request, based on the existing subscribers, load of handling the subscription (e.g., load with regard to collecting update information or bandwidth used to send a notification), etc. At step 276, the target semantics node 272 sends a semantics node subscription response to semantics node 271. The response at step 276 may include confirmation of the subscription and parameters that will be used in processing the subscription. At step 277, at some point in time after step 276, the target semantics node 272 detects a semantic notification trigger condition that matches the requested trigger received at step 274. At step 278, the target semantics node 272 sends a semantics node resource subscribe notify message to update semantics node 271 with regard to a particular semantics related resource.
Generally, a semantics related resource subscription can facilitate the semantics related resource discovery from a peer semantics node or parent semantics node. For example, based on the notification messages (which would include the URIs of newly created or updated semantics related resources stored on a semantics node), a semantics node may be able to perform discovery on semantics related resources of other nodes without sending discovery requests.
D. Linking and Association to Semantics Related Resources
The semantics related resources of a semantic node can be used in various ways. For example, semantics related resource representations may be retrieved from a semantics node and may be stored in a co-located manner in a network location where the data is stored (e.g., on a network server, on a device, on a gateway, etc.). Alternatively, the semantics of a resource may be stored on a semantic node and a link to the semantics may be co-located and stored along with the data. This semantic link may be stored in-line (i.e., embedded) within the data or may be stored separately (e.g. in a separate resource or attribute) alongside the data. Thus, through this linking to semantics-related resources, semantics can be applied to normal resources in an M2M system (e.g., <SCL>, <application>, <container> etc.). Typically, this linking will be created by the resource creator/generator, when the resources are created.
Continuing with the earlier example of a patient health monitoring application in
The hasType relationship may also be identified by a URL/URI which references a semantic description of the hasType relationship stored on the semantic node.
E. Grouping Optimization
If a group of resources have some similar semantics (e.g., all resources in the same application have the same semantics), the similar semantics may be applied to the application, instead of to each individual resource under that application.
For example, multiple instances of blood pressure monitoring data have the same semantics. Hence each instance may be associated with the same semantics (semanticsNode1/class/bloodpressure) as shown below:
By supporting this grouping optimization, the following association may also be valid:
F. Pushing Semantics Related Resources
As mentioned above, the classes, relationships, and terms that are hosted in a semantics node may be discovered and used by others. Based on the frequency of the requests, some of the semantics related resources may be pushed or mirrored in another semantics node for easier discovery and access. For example, after one semantics node detects the same forwarded discovery request from another semantics node a certain number of times (e.g., exceeding a policy defined threshold); it may decide to push a mirrored copy of the semantics related resource to that semantics node.
The semantics related resource pushing can happen between siblings, or between parent and child semantic nodes, as shown in
The following options may be used in order to keep the semantics related resource up-to-date. With reference to
The semantics related resource pushing can happen between siblings, or between a parent and child in either direction. For example, with reference to
G. Data/Semantics Related Resources Movement
Referring to
At step 317, semantics node discovery requests and responses are exchanged between semantics node 311 and semantics node discovery server 312 in order to build the hierarchy of semantics nodes, as well as sibling relationships. At step 318, semantics node 311 determines the address of semantics node 313. At step 320, a semantics related resource create request message is sent to semantics node 313 in order to copy the semantics related resource (and other data) that is used by device application 314. Semantics node 313 responds with a semantics related resource create response message, which may include an acknowledgement that the semantics related resource and other data has been copied successfully. At step 321, a semantics linkage update request message is sent to device application 314. The message at step 321 may include instructions for device application 314 to retrieve semantics related resources from semantics node 313. At step 322, the semantics linkage update response message may include an acknowledgement that the semantics node linkage is updated. At step 323, device application 314 retrieves semantics related resources in types of class, relationship, and term from semantics node 313.
V. ETSI M2M/oneM2M Examples
A. ETSI M2M Architecture with Semantics Node
As mentioned above, the semantic node concept described herein can be used to enhance the ETSI M2M architecture. Note the examples below (e.g.,
A semantics node may support a complementary resource structure as used in the service capability layer (xSCL) of the current ETSI M2M Architecture, and this resource structure may be applied to the semantics node described herein, in the manner illustrated in
As shown in
With reference again to
B. xSCL with Semantics Capability
In another example illustrated in
To support the example of
The classes, relationships, and terms collections under the <sclBase> resource 361 may each contain respective instances of semantics related resources hosted on the local SCL. Each instance may contain a semantic representation as well as have other attributes associated with it, such as discovery related information such as tags. These collections of semantic related resources may be accessed by clients having the proper access rights to do so.
C. Use Case Example of ETSI M2M Semantics Implementation
The semantics related resources managed by a semantics node may be associated and linked to resources in the ETSI M2M resource structure, such as <sclBase>, <application>, <container>, <contentInstance>, and the like. The following discussion illustrates how semantics related resources may be used to provide semantics information for a <contentInstance>.
In this example, assume that a temperatureReading class is defined and stored on scl1, and has URI of scl1/classes/temperatureReading. The relationship hasLocation is defined and stored on scl1 as well, and has URI of scl1/relationships/hasLocation. Additionally, the term ‘northeast China’ is defined and stored on scl1 too, and has URI of scl1/terms/northeastChina.
VI. 3GPP MTC Architecture Examples
As further mentioned above, the 3GPP MTC architecture may also be enhanced with the semantics support provided by the semantics nodes described herein. As shown in
While the oneM2M, 3GPP, and ETSI M2M architectures are described by way of background herein and may be used to illustrate various examples described hereinafter, it is understood that implementations of the examples described hereinafter may vary while remaining within the scope of the present disclosure. One skilled in the art will also recognize that the disclosed examples are not limited to implementations using the 3GPP or ETSI M2M architectures discussed above, but rather may be implemented in other architectures and systems, such as oneM2M, MQTT, and other M2M systems and architectures.
As shown in
As shown in
Referring to
Similar to the illustrated M2M service layer 22, there is the M2M service layer 22′ in the Infrastructure Domain. M2M service layer 22′ provides services for the M2M application 20′ and the underlying communication network 12′ in the infrastructure domain. M2M service layer 22′ also provides services for the M2M gateway devices 14 and M2M terminal devices 18 in the field domain. It will be understood that the M2M service layer 22′ may communicate with any number of M2M applications, M2M gateway devices and M2M terminal devices. The M2M service layer 22′ may interact with a service layer by a different service provider. The M2M service layer 22′ may be implemented by one or more servers, computers, virtual machines (e.g., cloud/compute/storage farms, etc.) or the like.
Referring also to
In some examples, M2M applications 20 and 20′ may include desired applications that communicate using an ontology publishing message, as discussed herein. The M2M applications 20 and 20′ may include applications in various industries such as, without limitation, transportation, health and wellness, connected home, energy management, asset tracking, and security and surveillance. As mentioned above, the M2M service layer, running across the devices, gateways, and other servers of the system, supports functions such as, for example, data collection, device management, security, billing, location tracking/geofencing, device/service discovery, and legacy systems integration, and provides these functions as services to the M2M applications 20 and 20′.
The M2M ontology management of the present application may be implemented as part of a service layer. The service layer is a software middleware layer that supports value-added service capabilities through a set of application programming interfaces (APIs) and underlying networking interfaces. An M2M entity (e.g., an M2M functional entity such as a device, gateway, or service/platform that may be implemented by a combination of hardware and software) may provide an application or service. Both ETSI M2M and oneM2M use a service layer that may contain the M2M ontology management and semantics interoperability messages of the present invention. ETSI M2M's service layer is referred to as the Service Capability Layer (SCL). The SCL may be implemented within an M2M device (where it is referred to as a device SCL (DSCL)), a gateway (where it is referred to as a gateway SCL (GSCL)) and/or a network node (where it is referred to as a network SCL (NSCL)). The oneM2M service layer supports a set of Common Service Functions (CSFs) (i.e. service capabilities). An instantiation of a set of one or more particular types of CSFs is referred to as a Common Services Entity (CSE), which can be hosted on different types of network nodes (e.g. infrastructure node, middle node, application-specific node). Further, the M2M ontology management and semantics interoperability messages of the present application can be implemented as part of an M2M network that uses a Service Oriented Architecture (SOA) and/or a resource-oriented architecture (ROA) to access services such as the M2M ontology management and semantics interoperability messages of the present application.
The processor 32 may be a general purpose processor, a special purpose processor, a conventional processor, a digital signal processor (DSP), a plurality of microprocessors, one or more microprocessors in association with a DSP core, a controller, a microcontroller, Application Specific Integrated Circuits (ASICs), Field Programmable Gate Array (FPGAs) circuits, any other type of integrated circuit (IC), a state machine, and the like. The processor 32 may perform signal coding, data processing, power control, input/output processing, and/or any other functionality that enables the M2M device 30 to operate in a wireless environment. The processor 32 may be coupled to the transceiver 34, which may be coupled to the transmit/receive element 36. While
The transmit/receive element 36 may be configured to transmit signals to, or receive signals from, an M2M service platform 22. For example, in an example, the transmit/receive element 36 may be an antenna configured to transmit and/or receive RF signals. The transmit/receive element 36 may support various networks and air interfaces, such as WLAN, WPAN, cellular, and the like. In an example, the transmit/receive element 36 may be an emitter/detector configured to transmit and/or receive IR, UV, or visible light signals, for example. In yet another example, the transmit/receive element 36 may be configured to transmit and receive both RF and light signals. It will be appreciated that the transmit/receive element 36 may be configured to transmit and/or receive any combination of wireless or wired signals.
In addition, although the transmit/receive element 36 is depicted in
The transceiver 34 may be configured to modulate the signals that are to be transmitted by the transmit/receive element 36 and to demodulate the signals that are received by the transmit/receive element 36. As noted above, the M2M device 30 may have multi-mode capabilities. Thus, the transceiver 34 may include multiple transceivers for enabling the M2M device 30 to communicate via multiple RATs, such as UTRA and IEEE 802.11, for example.
The processor 32 may access information from, and store data in, any type of suitable memory, such as the non-removable memory 44 and/or the removable memory 46. The non-removable memory 44 may include random-access memory (RAM), read-only memory (ROM), a hard disk, or any other type of memory storage device. The removable memory 46 may include a subscriber identity module (SIM) card, a memory stick, a secure digital (SD) memory card, and the like. In other examples, the processor 32 may access information from, and store data in, memory that is not physically located on the M2M device 30, such as on a server or a home computer. The processor 32 may be configured to control lighting patterns, images, or colors on the display or indicators 42 in response to whether the M2M ontology management messages (e.g., converting an ontology to a compatible message) in some of the examples described herein are successful or unsuccessful (e.g., exception handling (EHR), SLMP, or link profile submissions, etc.), or otherwise indicate the status of OPC 726, OCC 724, OR 727, ODC 723, or other semantics associated processes and components herein. For example, an organization of ontologies on a display as similarly described herein in
The processor 32 may receive power from the power source 48, and may be configured to distribute and/or control the power to the other components in the M2M device 30. The power source 48 may be any suitable device for powering the M2M device 30. For example, the power source 48 may include one or more dry cell batteries (e.g., nickel-cadmium (NiCd), nickel-zinc (NiZn), nickel metal hydride (NiMH), lithium-ion (Li-ion), etc.), solar cells, fuel cells, and the like.
The processor 32 may also be coupled to the GPS chipset 50, which is configured to provide location information (e.g., longitude and latitude) regarding the current location of the M2M device 30. It will be appreciated that the M2M device 30 may acquire location information by way of any suitable location-determination method while remaining consistent with an example.
The processor 32 may further be coupled to other peripherals 52, which may include one or more software and/or hardware modules that provide additional features, functionality and/or wired or wireless connectivity. For example, the peripherals 52 may include an accelerometer, an e-compass, a satellite transceiver, a sensor, a digital camera (for photographs or video), a universal serial bus (USB) port, a vibration device, a television transceiver, a hands free headset, a Bluetooth® module, a frequency modulated (FM) radio unit, a digital music player, a media player, a video game player module, an Internet browser, and the like.
In operation, CPU 91 fetches, decodes, and executes instructions, and transfers information to and from other resources via the computer's main data-transfer path, system bus 80. Such a system bus connects the components in computing system 90 and defines the medium for data exchange. System bus 80 typically includes data lines for sending data, address lines for sending addresses, and control lines for sending interrupts and for operating the system bus. An example of such a system bus 80 is the PCI (Peripheral Component Interconnect) bus.
Memory devices coupled to system bus 80 include random access memory (RAM) 82 and read only memory (ROM) 93. Such memories include circuitry that allows information to be stored and retrieved. ROMs 93 generally contain stored data that cannot easily be modified. Data stored in RAM 82 can be read or changed by CPU 91 or other hardware devices. Access to RAM 82 and/or ROM 93 may be controlled by memory controller 92. Memory controller 92 may provide an address translation function that translates virtual addresses into physical addresses as instructions are executed. Memory controller 92 may also provide a memory protection function that isolates processes within the system and isolates system processes from user processes. Thus, a program running in a first mode can access only memory mapped by its own process virtual address space; it cannot access memory within another process's virtual address space unless memory sharing between the processes has been set up.
In addition, computing system 90 may contain peripherals controller 83 responsible for communicating instructions from CPU 91 to peripherals, such as printer 94, keyboard 84, mouse 95, and disk drive 85.
Display 86, which is controlled by display controller 96, is used to display visual output generated by computing system 90. Such visual output may include text, graphics, animated graphics, and video. Display 86 may be implemented with a CRT-based video display, an LCD-based flat-panel display, gas plasma-based flat-panel display, or a touch-panel. Display controller 96 includes electronic components required to generate a video signal that is sent to display 86.
Further, computing system 90 may contain network adaptor 97 that may be used to connect computing system 90 to an external communications network, such as network 12 of
It is understood that any or all of the systems, methods and processes described herein may be embodied in the form of computer executable instructions (i.e., program code) stored on a computer-readable storage medium which instructions, when executed by a machine, such as a computer, server, M2M terminal device, M2M gateway device, or the like, perform and/or implement the systems, methods and processes described herein. Specifically, any of the steps, operations or functions described above may be implemented in the form of such computer executable instructions. Computer readable storage media include both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information, but such computer readable storage media do not includes signals. Computer readable storage media include, but are not limited to, RAM, ROM, EEPROM, flash memory or other memory technology, CD-ROM, digital versatile disks (DVD) or other optical disk storage, magnetic cassettes, magnetic tape, magnetic disk storage or other magnetic storage devices, or any other physical medium which can be used to store the desired information and which can be accessed by a computer.
In describing preferred examples of the subject matter of the present disclosure, as illustrated in the Figures, specific terminology is employed for the sake of clarity. The claimed subject matter, however, is not intended to be limited to the specific terminology so selected, and it is to be understood that each specific element includes all technical equivalents that operate in a similar manner to accomplish a similar purpose. Semantics related resources can be an ontology (an ontology could be composed of class, relationship and term), or an independent class, relationship, term.
This written description uses examples to disclose the invention, including the best mode, and also to enable any person skilled in the art to practice the invention, including making and using any devices or systems and performing any incorporated methods. The patentable scope of the invention is defined by the claims, and may include other examples that occur to those skilled in the art (e.g., skipping steps, combining steps, or adding steps between exemplary methods disclosed herein). Such other examples are intended to be within the scope of the claims if they have structural elements that do not differ from the literal language of the claims, or if they include equivalent structural elements with insubstantial differences from the literal languages of the claims.
This application claims the benefit of U.S. Provisional Patent Application No. 62/026569, filed on Jul. 18, 2015, entitled “M2M ONTOLOGY MANAGEMENT AND SEMANTICS INTEROPERABILITY,” the contents of which are hereby incorporated by reference herein.
Number | Date | Country | |
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62026569 | Jul 2014 | US |