Standards Development

Scope

This document specifies functional requirements and architecture about the following items for resource interoperability among heterogeneous IoT platforms (e.g., oneM2M, GS1 Oliot, IBM Watson IoT, OCF IoTivity, and FIWARE, etc.) through the conversion of resource identifiers (IDs) and paths (e.g., uniform resource identifier (URI)):

- Requirements for interoperability of resource IDs in the heterogeneous IoT platforms;

- Functional architecture for converting IDs and paths of resources on heterogeneous platforms; and,

- Functional architecture for mapping and managing resource IDs among heterogeneous platforms.

Purpose

IoT platforms are an essential factor to provide interoperability because it connects various devices (e.g., sensors, access points, and data networks) and provides service to users. Accordingly, various platforms (e.g., AllSeen Alliance AllJoyn, Apple HomeKit, FIWARE, Google Cloud IoT, GS1 Oliot, IBM Watson IoT, KETI Mobius, Microsoft Azure, OCF IoTivity, and PTC Thingworx, etc.) and related standards are being developed to provide various services.

However, current diverse platforms and related standards make it difficult to achieve interoperability and collaboration among heterogeneous IoT platforms. Different IoT platforms tend to have been developed using specific and unique identifier as shown in Table 1, and it is difficult to identify each resource among heterogeneous IoT platforms due to the resource-request format varying. Therefore, platform interoperability is challenging to resolve due to various issues such as support for diverse protocols, device discovery, well-defined semantic management, and processing of data formats in heterogeneous platforms.

Table 1 – Comparison of five IoT platforms’ resource identifier Platform Type Device ID Format Resource-Request Format oneM2M OID based [OID(Higher Arc)].[ManufacturerID].[DeviceTypeID].[DeviceSerialNo] (HTTP) [Server_IP_address]/[CSEBase_name]/[cse_name]{n}/[ae_name]/[cnt_name] GS1 Oliot OID based [GS1 OID({2.51})].[Identification Keys(1)].[ID Key Type], [GS1prefix].[CompanyNo].[ReferenceNo].[Serial/ExtensionNo] (HTTP) urn:epc:id:[ID Key Type]:[GS1 ID Key] IBM Watson IoT Client ID d:[orgID]:[deviceType]:[deviceID] (HTTP) GET /device/types/[typeId]/devices/[deviceId]/state/[logicalInterfaceId] OCF IoTivity Resource Type, Device ID [di], rt:oic.wk.d, oic.d.[*] (coap)://[IP_address]/[URL path] FIWARE Entity Type, Entity ID No specific restriction except some characters (e.g., <, >, etc.) (HTTP) [ip address]: [port]/v2/entities/[id] or [type]

To solve the resource interoperability issues, existing research mainly focuses on integrating and managing each platform’s ontology and a method of duplicating resources for different platforms in its platform. However, construct an integrated platform requires an accurate ontology and a relationship with the central platform. Furthermore, resource duplication has high memory issues and format conversion issues.

Therefore, to overcome the limitation of the existing approaches, this document focuses on mapping and converting the format of a resource identifier among diverse IoT platforms. In other words, this document analyses and converts identifier into desired request formats, including reconfiguring requests among heterogeneous IoT platforms as appropriate for the requested resources.