1. oneM2M-ARC-2013-0591-Enhancement_on_resources Some thoughts on oneM2M resources Group Name: WG2 Source: Norio Uchida, NEC, n-uchida@cq.jp.nec.com, Barbara Pareglio, NEC, barbara.pareglio@neclab.eun-uchida@cq.jp.nec.combarbara.pareglio@neclab.eu Meeting Date: 2013-12-02 Agenda Item: Contributions

2. Introduction This contribution aims to clarify what should be defined in Stage 2 and what is part of stage3. This contribution also provides some recommendations NOTE: The following analysis assumes ROA, though there are still discussions on SOA v.s. ROA. © 2013 oneM2M Partners oneM2M-ARC-2013-0591-Enhancement_on_resources 2

3. Illustrative Presentation -- resources, contents and attributes © 2013 oneM2M Partners oneM2M-ARC-2013-0591-Enhancement_on_resources 3 Structure of resources XML JSON MPEG Object, Array, … Encoded binary Scope of Stage 2 Stage 3 or left to implementation Attributes Each resource is represented in a certain form (=content-type). Each content type has its own inner structure.

4. Recommendations a.Stage 2 should only describe the interface, meaning the resource with the description of the elements of the resource. Stage 2 should not specify how the information is carried on the protocol level. b.Stage 2 should define what is accessible (resource and elements of a resource) and managed by CRUD operations (Create/Read/Update/Delete). c.Note that attributes are meta-data to annotate the content of the resource. – Attributes should be distinguished from the content of the resource. – The list of attributes can be basically identical for every content-type. – They may be equivalent to the response of HTTP HEAD method if the protocol is bound to HTTP. © 2013 oneM2M Partners oneM2M-ARC-2013-0591-Enhancement_on_resources 4

5. Recommendations (Cont.) d.Resources should be linked via URL. The linkage structure should be independent from hierarchical notation of URI. – The following are valid. d.Parent resource URL: http://example.com/onem2m/aa/foohttp://example.com/onem2m/aa/foo e.Child resource URL: http://example.com/onem2m/bb/cc/xx/barhttp://example.com/onem2m/bb/cc/xx/bar e.A new attribute is required to indicate the content-type (or media- type) of a resource. – Most resources are supposed to be represented with existing content- types. MIME-type can be reused, e.g. text/html, text/xml, appllication/json, video/mpeg. – The specifics of how it is defined it will be part of stage 3 – Don’t reinvent the wheel! © 2013 oneM2M Partners oneM2M-ARC-2013-0591-Enhancement_on_resources 5

6. Conclusions If the concepts are agreed, the Functional Architecture should: – Clearly defines the elements (resource, attributes) for which atomic actions applies (CRUD operations) – Make the structure independent from the hierarchical notation of the URIs, but defines the relationship between resources. © 2013 oneM2M Partners oneM2M-ARC-2013-0591-Enhancement_on_resources 6