Resource Announcement Procedures Group Name: WG2 Source: Rajesh Bhalla, Hao Wu - ZTE Meeting Date: Agenda Item: TBD

Background © 2013 oneM2M Partners 2

Resource Announcement A resource can be announced to one or more remote CESs to inform them of the existence of the original resource The original resource can, thereby, be discovered more easily since the remote CSEs with interest in specific resources do not have to contact huge number of other CSEs The announced resource has a limited set of attributes though, and a limited set of child resources from the original resource The announced-resource has a link to the original resource at the resource hosting-CSE, thereby allowing access to the attributes that are not available at the announced-resources © 2013 oneM2M Partners 3

Resource Announcement (cont.) The attributes of an announce-able resource are categorized as: – MP (Mandatory Present): Such attributes in the original resource are mandatory to be present in the announced resources. – OP (Optional Present): Such attributes in the original resource may or may not be present in the announced resources depending on the contents of the "announcedAttribute" attribute of the original resource – NP (Not Present): Such attribute shall not be present in the announced resource. © 2013 oneM2M Partners 4

Resource Announcement (cont.) Three attributes are have been specified to support resource announcement: © 2013 oneM2M Partners 5

Resource Announcement (cont.) Resource announcement is accomplished by using CREATE operation, whereby an announced-resource is created at the remote CSE indicated by the address (e.g., URI) in announceTo attribute – attributes of type "MP" are created at the announced-resource – attributes of type "NP" are not created at the announced-resource – attribute of type "OP" included in the announcedAttribute attribute at the original resource are created at the announced-resource Resource de-announcement is accomplished by using the DELETE operation – The announced-resource at the remote CSE is deleted when the address (e.g., URI) of the remote CSE is removed from the announceTo attribute at the original CSE – All announced-resource are also deleted when the original announced resource is deleted © 2013 oneM2M Partners 6

Resource Announcement (cont.) The original resource maintains synchronization between the values of attributes at the original resource and at all announced resources For any updates to the values of announced attributes, the original resource can use UPDATE procedure to synchronize such attributes at all announced resources © 2013 oneM2M Partners 7

Issues © 2013 oneM2M Partners 8

Attribute Announcement and De-Announcement Need to maintain synchronization for "OP" type attributes that are included in the announcedAttribute attribute at the original resource and similar attributes at the announced-resources An update to the announcedAttribute attribute at the original resource results in such "attribute" announcement or de-announcement at all announced-resources How to accomplish, such attribute announcement de-announcement is an open issue – current specification proposes to use CREATE and DELETE operations for "attribute" announcement and de-announcement respectively The issue is: – CREATE and DELETE operations are applicable to "resource" as whole; and NOT to individual "attributes" © 2013 oneM2M Partners 9

Solution Option -1 When a resource is announced (by using CREATE operation) – All attributes of type "MP" are created at the announced-resource – Attributes of type "NP" are NOT created at the announced-resource – Attributes of type "OP" included in the announcedAttribute attribute at the original resource are created in the announced-resource – In addition, the optional attributes at the original resource that are not included in the announcedAttribute attribute are also created at the announced-resource, but their value is set to NULL Resource UPDATE operation is then used to announce/de-announce the “attributes” – When an additional attribute needs to be announced, UPDATE operation updates the value of such attribute at the announced-resource – When an attribute need to be de-announced, UPDATE operation sets the value of such attribute to NULL at the announced-resource(s) How a NULL value is implemented is Stage-3 issue. It could be via means such as the use of certain flags etc. © 2013 oneM2M Partners 10

Solution Option - 2 UPDATE operation is used for resource announcement/de- announcement An optional meta information element is proposed for inclusion in such UPDATE Request messages – annc: optional; for attribute announcement and de-announcement Value set to Announce: Announce attribute(s) identified in cn parameter Value set to De-Announce: De-announce attribute(s) identified in cn parameter. – cn parameter includes the attributes to be announced or de- announced Identifies the additional "OP" type attribute(s) that are to be announced, with their associated values Identifies the existing "OP" type attribute(s) that are to be de-announced © 2013 oneM2M Partners 11

Solution Option - 3 Enhance CREATE and DELETE operations for being applicable at “attribute” level also One method of doing that could be to use optional annc meta information – when used with CREATE operation, the presence of such annc meta information makes the operation applicable to the attribute(s) included in the cn parameter – when used with DELETE operation, the presence of such annc meta information makes the operation applicable to the attribute(s) included in the cn parameter © 2013 oneM2M Partners 12

Solution Choices © 2013 oneM2M Partners 13

Solution Choices Option 3 necessitates to change the scope of CREATE and DELETE operations The scope of CREATE and DELETE operations needs to be changed from "resource" level to "attribute" level The need to support (more) parameters for DELETE operation (cn, annc); major change Needs significant enhancements at several places in TS-0001 © 2013 oneM2M Partners 14

Solution Choices Option 1 and Option 2 recommend the use of UPDATE operation The scope of Update operation is at "attribute" level, hence no change in the scope to the operation Relatively lesser enhancements needed to TS © 2013 oneM2M Partners 15

Solution Preference is for Option 1 or Option 2 Guidance solicited for the preferred approach – Option 1 ?? – Option 2?? © 2013 oneM2M Partners 16

Thanks © 2013 oneM2M Partners 17