Re: [Mops] AD review of draft-ietf-mops-ar-use-case-14

[Renan Krishna <[e-mail]>]

Hi Everyone and Happy New Year!
Many Thanks Eric for your review. We will get back to you with our response shortly!
Regards,
Renan

-----Original Message-----
From: Eric Vyncke (evyncke) <evyncke=[e-mail]> 
Sent: Friday, January 5, 2024 4:41 PM
To: [e-mail]; Renan Krishna <[e-mail]>; [e-mail]
Cc: [e-mail]
Subject: AD review of draft-ietf-mops-ar-use-case-14

Hello and Happy New Year,

As usual, I have done my AD review of draft-ietf-mops-ar-use-case-14 before processing with the publication process (i.e., IETF Last Call).

All the comments (except when noted otherwise) must be either replied to (and feel free to disagree with me of course) or acted upon (e.g., with new text).

# Shepherd's write-up

For Stephan (the shepherd), the shepherd’s write-up would benefit if the answers were clearly delineated from the questions. Else, I find the shepherd well written, thank you.

# Generic

The I-D has many typos in it and uses wrong punctuation marks (e.g., no space char after a comma or a dot, or missing a comma after lead complement, or missing a '-' between two words), please use a spell checker (for your convenience, I have attached a MS-Word copy of the I-D so you can use Word spell checkers).

The text often uses ‘we’, and this is quite unusual for an IETF documents. Consider rephrasing all sentences having “we”.

# Abstract

`different form factors`, unsure whether it is the right term here (my non-English reading assumes physical format).

# Section

`Reality` or `Realty` ?

# Section 1

Some middle parts are 'hand waving', e.g., unsure what SDN has to do here as in `with open interfaces using SDN`.

# Section 2

Consider removing section 2 as there is no normative language in the I-D (usual for an informative I-D) and the template is the old one.

`Such techniques enable XR applications requiring low-latency and high bandwidth to be delivered by mini-clouds running on proximate edge devices` really looks like a marketing statement. Consider adding justification (with references) or removing it.

Unsure what `GPS` is doing here... Also, do not use "GPS" as it is a commercial offering by a US company, let's be global and GNSS (global navigation satellite systems).

Please explain ` heavy-tailed` in this context.

Please expand "QoE" at first use.

# Section 3

This section is about AR while the I-D is about XR. Suggest to rename the document.

# Section 3.1

Please explain ` annotated point cloud based model` to the reader.

You may also expand 2D, 3D, 5D, ... in a generic way (and for myself, I have no clue what 5D represents).

# Section 4

The section title "requirements" only vaguely relates to the first paragraph (i.e., "Technical challenges and solutions" would be better) *and* do not really fit the 2nd paragraph, which is more about solution/workaround.

Has " 360 degree streaming" been defined before ?

`the 3GPP requires and supports an Ultra Reliable Low Latency` while the 3GPP reference is only a study and not a specification.

Is there any justification for the assertion ` This is because with such distributions, law of large numbers works too slowly, the mean of sample does not equal the mean of distribution,`?

# Section 5.1

`parameters that capture the characteristics of XR application behavior are heavy-tailed` but the section title is about "AR" ?

The term ` UE device` is more suitable for a 3GPP document, for IETF suggest to use "user device".

Is there a previous definition of ` 6DoF`?

The 2nd paragraph has many assertations without any reference or justification.

# Section 5.2

Is `when operationalizing a network` correct English ?

s/ The following issues were identified.:/ The following characteristics were identified:/ ?

I would refrain using a 2002 reference for ` The packet loss rates in wireless links between XR devices and the Edge server can be as high as 2% or more [WIRELESS_1].` and the actual current number is probably better. I.e., this paragraph can probably be removed.

I do not see a matching row in table 2 for the assertion `the required bandwidth for our use case as discussed in section 5.2 is 200Mbps-1000Mbps`.

# Section 8

Oxford comma is probably required in the list of names.