Re: [T2TRG] Fwd: New Version Notification for draft-robles-t2trg-functionalitydescription-00.txt

[Alessandro Bassi <[e-mail]>]

Hi,

I've read this draft and I have one comment/question.

Indeed, I believe that a terminology section is very important.

<quote>

An IoT device can be considered to be semantically composed as a set of
objects, with each object being a set of resources. The resource is an
atomic piece of device information that can be managed. This document
presents three level of functionalities as shown in Figure 1: Device
Functionality, Object Functionality, Resource Functionality, that
together delineate the complete functionality of the device. (TODO
provides specific definition for each one)

</quote>


I assume that "IoT device" and "device" in this context means the same.

In this context, my definition of device is an artifact that mediates
between the physical and the digital world; typically, a device is a
sensor or an actuator.

My definition of Resource is a software component that provides data
from or is used in the actuation of a physical entity.

Resources can be on-device or not (in the second case, let's call them
Network Resources).

Technically, a Device hosts an on-device resource, which is associated
to a virtual entity that is the "digital twin" (or representation) of a
physical entity related to the device.

For a practical example, a Physical Entity is a cow. A Device is a cow's
collar with a GPS sensor. A Resource is a positioning software for the
collar. (A Service, in this case, would be a system that sends a signal
to a cow if she is standing too long in front of the food or water, so
she would move away and the other cows can eat or drink as well). BTW,
from a Service point of view, it is quite irrelevant if the Resource is
on-device or in the Network: what it needs to know is the position of
the cow.  

Given the above, I have no clue what an object is in the quoted text.

Furthermore, Functionalities of a system can be grouped and depend on a
specific view: we can have communication functionalities, or security,
or management, or ... In the example in the text (the fire one), it
seems to me that the functionality is related to the Virtual Entity: the
physical entity is the fire and a thermometer OR a video share the same
capability (let's simplify here) to understand that a fire is going on,
and therefore are semantically comparable. 

Now, neither of them can dim a light - that would be a service that is
using different resources on different devices. To fulfil your goal
(alert in case of fire) you would actually need two set of resources
that have nothing in common (a fire detector and a light).

I see the point in making the thermometer and the video semantically
close in case of detecting a fire, as they can both be fire detectors,
but <brainstorming mode> somehow this sounds "almost" like applying
fuzzy logic to UML notations (a video IS A "kind-of" fire detector, a
thermometer IS A fire detector ... ) </brainstorming>

Anyway, could you please give your definitions of "device", "object" and
"resource", and what is a "functionality"?

thanks!

--alex

On 27. 03. 19 9:51, Ines Robles wrote:
>
> Dear all,
>
> We present in the following draft a way to describe the different
> functionalities (from manufacturer and the ones defined by the user)
> that an IoT device can present. Additionally, we present a metric to
> determinate similar functionalities between devices.
>
> We are trying to figure out a way to define the different
> functionalities inside the data-model.
>
> Comments welcome,
>
> Ines and Bill
>
> ------------------------------------------------------------------------
> *From:* [e-mail] <mailto:[e-mail]>
> <[e-mail] <mailto:[e-mail]>>
> *Sent:* Tuesday, March 26, 2019 4:18:12 PM
> *To:* Bilhanan Silverajan; Robles Maria; Robles Maria; Bill Silverajan
> *Subject:* New Version Notification for
> draft-robles-t2trg-functionalitydescription-00.txt
>  
>
> A new version of I-D, draft-robles-t2trg-functionalitydescription-00.txt
> has been successfully submitted by Maria Ines Robles and posted to the
> IETF repository.
>
> Name:           draft-robles-t2trg-functionalitydescription
> Revision:       00
> Title:          IoT Semantic Functionality Description
> Document date:  2019-03-26
> Group:          Individual Submission
> Pages:          8
> URL:           
> https://www.ietf.org/internet-drafts/draft-robles-t2trg-functionalitydescription-00.txt
> Status:        
> https://datatracker.ietf.org/doc/draft-robles-t2trg-functionalitydescription/
> Htmlized:      
> https://tools.ietf.org/html/draft-robles-t2trg-functionalitydescription-00
> <https://tools.ietf..org/html/draft-robles-t2trg-functionalitydescription-00>
> Htmlized:      
> https://datatracker.ietf.org/doc/html/draft-robles-t2trg-functionalitydescription
>
>
> Abstract:
>    This document defines firstly functionality levels for IoT devices
>    that describe the device capabilities at the granularity of devices,
>    objects and resources.  It additionally presents a metric to measure
>    the functional similarity between the manageable properties of any
>    two IoT devices, called Functionality Distance (FD), which is defined
>    as the indication of the extent to which one device can be
>    substituted for the other.
>
>                                                                                  
>
>
>
> Please note that it may take a couple of minutes from the time of
> submission
> until the htmlized version and diff are available at tools.ietf.org
> <http://tools.ietf.org>.
>
> The IETF Secretariat
>
>
> _______________________________________________
> T2TRG mailing list
> [e-mail]
> https://www.irtf.org/mailman/listinfo/t2trg