Re: [STDS-802-16] [802.16n][DC] Discussion on definition of HR-MS DC and Forwarding to Network
Eldad and all,
Thanks very much for the summary provided by Eldad. I agree with the text
summarized by Eldad.
I also add some response to Eldad's question inline.
Regards.
Haiguang
-----Original Message-----
From: Ming-Tuo ZHOU [mailto:mingtuo@nict.com.sg]
Sent: Thu 4/21/2011 6:20 PM
To: STDS-802-16@LISTSERV.IEEE.ORG
Subject: [STDS-802-16] [802.16n][DC] Discussion on definition of HR-MS
DC and Forwarding to Network
Dear 16n participants,
I'd like to trigger discussion of definition of HR-MS direct
communication and HR-MS forwarding to network, since from many
discussions it seems there are some confusion regarding them. In my
opinion, it is necessary to have a clear common understanding of these
two functions for development of technical details in a more smooth way.
Anyone is welcome to bring his/her understanding of these two functions
by replying this email. I hope after several rounds of email discussion,
we can achieve some consensus regarding these two functions.
The discussion may be started by answering follow questions:
1. what is HR-MS direct communication (DC)?
Haiguang: HR-MS direct communication means, the two HR-MSs involved in
the communication
are the producer and consumer of the data packets. That is,
the source HR-MS
pass the data packet down from upper layer to MAC and the
destination HR-MS
pass the packet to upper layer from MAC after receiving from
the air.
Clarification: the producer and consumer here are from the
view of MAC. It does
not mean the packet is originated from the source HR-MS and
terminated at the
destination HR-MS.
Eldad: suggest the following text (editorial cleanup, I think it means
the same)
The two HR-MS that are in direct communications with each other are the
source and the sink of data. Packets are passed from upper layers to MAC
at the source and back to upper layers at the sink HR-MS.
2. what is HR-MS forwarding to network (FTN)?
Haiguang: HR-MS forwarding means the forwarding HR-MS either forwards
the data packet to
HR-BS or to the HR-MSs that access the network via the
forwarding HR-MS.
The forwarded packet will not be passed to upper layer.
Instead, it is forwarded to
next hop at MAC layer.
Eldad: again I agree with the principle and suggest the following
wording:
An HR-MS that forwards data to infrastructure node or to another
forwarding HR-MS that is attached to an infrastructure node (if
multi-hop is supported) does so without passing any data to or from
higher layers.
3. what's difference between HR-MS DC, HR-MS FTN, and HR relay/local
forwarding?
Haiguang: The differences are:
* For HR-MS DC, at the source HR-MS, the data packets are from
upper layer and are passed
to upper layer protocol at the destination HR-MS.
* For HR-MS FTN, the data packet is forwarded to next hop at
MAC layer. The data packets are
not handled by upper layer protocol. HR-MS who forwards data
packet is still an HR-MS. It
only has a very simple relay function and can only support
very few nodes, one or two.
From other HR-MSs' view, HR-MS performing the relay function
is still an HR-MS.
HR relay is a kind of infrastructure station designed for the purpose of
relay. It is complex and like a BS. It is designed to support many MS in
network access.
* Local forwarding means the infrastructure station between MS and BS
forwards data packets from downstream HR-station to destination HR-MS
without passing it to upstream infrastructure stations.
A general case is a HR-RS forwards the data packets from one of its
HR-MS (source) to another HR-MS which is the destination.
Eldad:
- Not sure what is the meaning of "From other HR-MSs' view, HR-MS
performing the relay function is still an HR-MS." - could you please
clarify?
- From the SRD, an HR-RS is " A relay that complies with the
requirements for relays in this amendment". This is an amendment to
802.16n or 2009, which means that an HR-RS is an RS or ARS as amended by
802.16n. I don't think we need to define it any further, although we'll
need to specify how to implement the requirements we have agreed to in
the SRD.
Haiguang: My meaning is that the HR-MS should aware that the MS forwards
data control for it is an HR-MS. It is not a relay station.
If you have more questions that may help to understand these two
functions, please also bring them here.
Finally, the following is expected to be made:
[Consensus: ]
Thank you very much.
Best regards,
Ming-Tuo Zhou
16n DC RG co-chair