AW: [802.21] Comments on Ref. Model
Hi Ulises,
at first thank your for the comments and for keeping up the discusssion.
Indeed there are many similarities between different representations. The
main background why we put up the figure is to have a simple but effective
and abstract figure.
>1) Ref (1) shows the transport of MIH services between Lower Layer at the
>network side and 802.21 MIH function as a local interface. However there
>are other cases to consider. For example, in ref (3) we show this scenario
>as the collocated case. However we also show that these services can
>transported over higher layer transport or layer 2 as well. Furthermore
>in ref (3) we stress that at the network side there is no direct
communication
>between 3GPP/3GPP2 lower layers and the MIH function.
In Ref(3) you have elaborated the network side too whereas in Ref(1) it is
abstract. I feel Ref(3) is subset of Ref(1). Further, there is a new entity
called "MIH Network Entity" apart from MIHF. The function of this entity is
not clear to me.
>2) In ref (3) 3GPP and 3GPP2 communicates toward a MIH Network Entity using
>higher layer transport. This is not described in ref (1)
Infact it is there, MIHF communicating with Upper Layers. And upper layer
is communicating with MIHF peer over higher layer protocols.
>3) However the scenario where just a L3 interface is used to communicate
>between two MIH peers is not described. This is depicted in ref (3)
>as double-headed arrow that goes from MIH to MIH simply using a Higher
>Layer Transport
Yes, that is the reason we proposed to add it in our reference model.
>4)...Here I have a comment and a question: If it is already included
>in the box, why would we need to specify a L2 transport? ...
The reason behind this is to keep the mechanism of L2 transport independent
of media (as in Ref(2)). An example to this is typical Ethernet frame.
Though it is 802.3, it can be carried over different medias like 802.xx.
We can also think here of PPP, ATM or what else.
The representation is some what similar to stating "higher layer", here
too we are not mentioning whether it is TCP or UDP or some other protocol.
Presently, it is clear to all it will be IP.
>...Also from ref (1) the common layer 2 transport (or lower layer) depicted
>in the figure indicates that both 3GPP/3GPP2 and 802 components used the
>same L2 transport, this is not accurate...
As I mentioned, the intention was to put an abstract figure which tries to
cover all the concepts. Again, the model you mentioned can be seen as
sub-set
of the it.
>...1) Over the management plane (e.g.,through the introduction of a new an
>action frame format), and 2) Over the Data Plane using LSAP (through the
>introduction of a new ethertype).....
From my understanding both are layer 2.
I have noted that you have changed the 802-Interface at client side in the
doc attached to the email. I like it better than the previous diagramm :-)
The point which needs a clarification from my side is, how MIHF communicates
with MGMT (over SAPs or over Transport protocol). This question is also
valid
for all local interactions.
With best regards,
Kalyan
-----Ursprüngliche Nachricht-----
Von: Olvera-Hernandez, Ulises
[mailto:Ulises.Olvera-Hernandez@InterDigital.com]
Gesendet: Montag, 14. November 2005 21:39
An: Koora Kalyan Com Bocholt; STDS-802-21@listserv.ieee.org
Betreff: RE: [802.21] Comments on Ref. Model
Hi Kalyan,
I noticed that in the introduction you referred to two contributions
21-05-0413....(let us call it ref (1)) and 21-05-0423..-(let us call it ref
(2)) where as I understand you based the document for discussion. I would
like us to consider also contribution
"21-05-0425-00-0000-InterDigital3GPPAmendments" as it is addressing the same
issue (let us call it reference (3) for the purpose of this discussion). If
we look at section 5.1.1 from ref(3), the proposed reference model is
fundamentally the same reference model that we agree to use for our
presentations to both 3GPP and 3GPP2. I find that this model looks quite
similar to the one you are proposing except for the
following:
1) Ref (1) shows the transport of MIH services between Lower Layer at the
network side and 802.21 MIH function as a local interface. However there are
other cases to consider. For example, in ref (3) we show this scenario as
the collocated case. However we also show that these services can
transported over higher layer transport or layer 2 as well. Furthermore in
ref (3) we stress that at the network side there is no direct communication
between 3GPP/3GPP2 lower layers and the MIH function.
2) In ref (3) 3GPP and 3GPP2 communicates toward a MIH Network Entity using
higher layer transport. This is not described in ref (1)
3) Ref (1) shows communication from MIH function in the client station to
its peer at the Network through a higher layer transport. This is consistent
with ref (3). Then the interface goes through what it is referred to as
'Higher Layer' before it communicates with the MIH peer. This is very
similar to ref (3) for case where the interface goes through the MIH Network
Entity (e.g., the Upper Layer being part of the MIH Network Entity). However
the scenario where just a L3 interface is used to communicate between two
MIH peers is not described. This is depicted in ref (3) as double-headed
arrow that goes from MIH to MIH simply using a Higher Layer Transport.
4) You also indicate that the management plane has been replaced by what it
is referred to as L2 transport and that the Management Plane is technology
specific and therefore it is already covered in the corresponding box. Here
I have a comment and a question: If it is already included in the box, why
would we need to specify a L2 transport? Also from ref (1) the common layer
2 transport (or lower
layer) depicted in the figure indicates that both 3GPP/3GPP2 and 802
components used the same L2 transport, this is not accurate. Furthermore, we
have discussed two different mechanisms to send MIH information both peer to
peer and locally: 1) Over the management plane (e.g.,through the
introduction of a new an action frame format), and 2) Over the Data Plane
using LSAP (through the introduction of a new ethertype). It is not obvious
how the "Lower layer Transport" transport handles these two mechanism, in
particular considering that they interface between the LLT and the MIH
function is depicted as a local interface. This might be accurate for
locally generated events but not for peer to peer remote events.
I have taken some of the concepts that you introduce and they are now
reflected in a newer version of fig.3 from ref (3). I added both snippets
from this e-mail and fig.3 from ref (3) to your document and I'm sending it
back attached to this e-mail. I enabled change tracking within the document,
although changes are quite obvious. Comments are appreciated.
Regards,
Ulises
-----Original Message-----
From: Koora Kalyan Com Bocholt [mailto:kalyan.koora@SIEMENS.COM]
Sent: Thursday, November 10, 2005 8:32 AM
To: STDS-802-21@listserv.ieee.org
Subject: [802.21] Comments on Ref. Model
Hello all,
after going through couple of presentations/comments, we had some internal
discussions on the reference model. Please find our point-of-view in the
attached document. This can be discussed in detail later in the IEEE
meetings or on the reflector.
Awaiting your comments,
with regards,
Kalyan