## 7 Conclusions  
In this paper, we present a consistent registration and discovery scheme using RAML to enable the information of an IoT device and WSP through the embedded RD server in the OCF-based IoT network. The registration enables the IoT device and publishing client to register the information of the device and WSP using the RAML-based profile. Through the registration, the IoT device registers the IoT device information to the RD, and the publishing client registers the WSPs to the RD. The registered information is included in the RAML definition that is the profile for describing the resource information. The RAML-based profile in the payload of a registration request that involves the basic information of a service provider, such as IoT device and WSP. The resource is also described for accessing the service by the IoT client. Therefore, the RD server provides the information to the IoT clients using the registered information that is published by IoT device and the publishing client based on the RAML definition. The discovery service enables the users to retrieve the service information using the IoT client. Through the discovered information, the IoT client accesses the services of IoT device and WSP. Therefore, using the embedded RD server in the OCF-based IoT network, the registration and discovery of services from heterogeneous providers are supported by the consistent scheme. Moreover, through the message forwarding service of RD server, the users use the same IoT client to consume the services from the IoT network as well as the Internet.  
In the future, we will extend the functionalities to support more communication solutions for enabling transparent access to heterogeneous IoT devices. Currently, the proposed scheme only enables the registration of OCF devices and WSPs from the networks of the OCF over the CoAP and the Internet based on the HTTP. The discovery interface is provided to OCF clients for discovering the registered IoT devices and WSPs. Based on the proposed scheme, we will implement a registration interface for the IoT devices which are deployed in the constrained environment using low-energy based communication solutions such as zigbee, BLE, and OCF IoTivity over BLE. The registered IoT resources shall be represented as HTTP-based virtual resources to appear in the Internet. Therefore, this is a consistent discovery interface to provide clients for discovering IoT resources.  
[PERSON] and [PERSON] designed the overall system. [PERSON] implemented the overall system and performed experiments. [PERSON] and [PERSON] wrote this paper.  
This work was supported by Institute for Information and communications Technology Promotion (IITP) grant funded by the Korea government (MSIT) (No.2018-0-01456, AutoMaTa: Autonomous Management framework based on artificial intelligent Technology for adaptive and disposable IoT), and this research was supported by the MSIT (Ministry of Science and ICT), Korea, under the ITRC (Information Technology Research Center) support program (IITP-2017-2016-0-00313) supervised by the IITP (Institute for Information & communications Technology Promotion). Any correspondence related to this paper should be addressed to [PERSON].  
The authors declare no conflict of interest.