----- Original Message -----
Sent: Tuesday, July 06, 2004 8:45
PM
Subject: RE: [STDS-802-16]
[STDS-802-16-MOBILE] [Handoff] HO Ad-Hoc Consensus document, reply
comments
Phil, Prakash,
For the two issues I raised in my reply comments, I think we
should be able to resolve them over emails. My understanding was
since there weren't enough time to go through the consensus
contributions during the last HO adhoc call as was originally planned in the
agenda, any remaining issues should be raised in the reply
comments.
Regarding my comments on contribution 146, I would like to see the
service level support and available resource information added to the
MOB-NBR-ADV, as proposed in contribution 224. We have discussed this during
the last HO adhoc call and identified several options as Prakash has
summarized in the HO adhoc call minutes. I am in favour of putting the
information into a new TLV type so that it can be optional. Also, to
allow the option of only broadcasting service level support, we can set the
4-bit resource available field to '1111' as was suggested during the
call.
'Service level supported' is a confusing name (could be confused with
SLP use in 16e); should change it to 'Scheduling Service Supported' to be
consistent with language in 802.16-2004. Are we really getting enough
benefit out of providing this information to justify the bits, even if it is
just four bits? I am not sure. Can the HO policy manager benefit that
much from knowing what type of Scheduling Service the Target BS supports,
obtained by an untimely NBR-ADV, versus the available mechanisms of
getting real SLP responses back from MSS-to-Target BS ranging or
MSS-to-Serving BS-to-Target BS HO-REQ/RSP and backbone
inquiries?
Regarding radio resource availability advertising, we have had
discussions regarding the type and value of providing similar information in
the past, with no consensus. The problem usually has to do with the
accuracy and timeliness of the information. For instance, your
contribution's use of 'Available radio resource'; this
can easily be a very misleading number since most networks will likely
allocate excess capacity to Best Effort traffic, using up most
or all available subchannels/symbols in a given frame, giving
the illusion of saturated capacity when, in fact, substantial high-demand
service capacity may remain. Also, capacity constraints can fluctuate
dramatically in short-time intervals, making snap-shots reported in one
second intervals unreliable.
[Fong, Mo-Han] I agree that we should change the name to 'Scheduling Service
Supported'. Our intention of providing resource and scheduling
service supported information in MOB-NBR-ADV is to allow the MSS
to avoid unnecessary scanning and possible associations to neighbor BSs
that cannot support the service level required by the MSS. Although it is
true that the MSS will eventually obtain the SLP information after
association or HO messaging exchange, there will be unnecessary interruption
to MSS data transmission/reception with the Serving BS due to association or
unnecessary HO messaging exchange.
Regarding the available radio resource information, the BS should set
the value according to the call admission policy (the same policy that would
be used when the BS decides whether to admit a MSS during HO or network
entry), which is typically based on average network loading rather than
based on instantaneous loading. In the call admission policy, the BS should
take into consideration of the average loading occupied by the existing
non-best-effort MSSs as well as the loading the BS intend to offer to the
existing best effort MSSs and then evaluate what is the extra radio resource
available.
Regarding my comments on contribution 144, I would like to get
some clarification on whether HO Indication is required for
non-contention based ranging since the target BS must have known that
the MSS is performing handover, from the fact that the target BS sends a
Fast_UL_ranging_IE to allocate the UL resource.
Right now, the only mechanism for a Target BS to
become aware that it needs to place a Fast_IE slot for non-contention based
ranging is through MSS-to-Serving BS HO-Ind with a Serving BS-to-Target BS
backbone message requesting the allocation. However, there is a
contribution seeking to make Fast_IE allocations available for
ranging/Association through the SCN-REQ/RSP mechanism. And there is
another contribution (actually, two contributions, I think) seeking to add
PHY specific HO ranging codes to OFDMA. With an OFDMA HO ranging code,
an MSS could signal directly to the Target BS its need for a Fast_IE,
non-contention based ranging opportunity, without having to request through
the Serving BS at all.
[Fong, Mo-Han] My understanding is if the MSS sends OFDMA ranging code, the
BS will send the CDMA_Alloc_IE, rather than the Fast_ranging_IE. The
Fast_ranging_IE is only applicable for the case when there is backhaul
communication between serving and target BS during HO or even during
association as proposed in another contribution. In that case, the MSS does
not need to send OFDMA ranging code. Please correct if that is not the case.
But if that is the case, then when the MSS receives a Fast_ranging_IE, the
MSS does not need to include the HO indication TLV with the
RNG_REQ.
Thanks.
Mo-Han
I am 100% certain that I can resolve these
issues/questions to Vladimir and Mo-Han's satisfaction, but these are
consensus contributions and I need approval of the group to do so.
There is not going to be any time for me to negotiate acceptable changes,
make them, post them for review, revise, and re-submit.
This is better handled via email, rather than
by teleconference, to give me an opportunity to expound upon the rationale
of the group for various decisions.
Thanks,
Phil
----- Original Message -----
Sent: Tuesday, July 06, 2004 7:09
PM
Subject: Re: [STDS-802-16]
[STDS-802-16-MOBILE] [Handoff] HO Ad-Hoc Consensus document, reply
comments
Given that these contributions have been out
there for a while, a reject reply comment could have been avoided. An
option is to have a short telecon tomorrow morning to see if these
issues can be addressed.
Vladimir,
Phil, Mo-Han, others? - can we resolve over email or should we try to
have a call tomorrow?
-Prakash
I received the following reply comments
requesting/requiring changes to the listed HO Ad-Hoc Consensus documents
and am seeking input on applying changes, if any, to the
contributions. These are Consensus contributions and I am
reluctant to unilaterally make changes to the documents without
circulating and receiving comments.
Document: C80216-04_146
Reply Comment: from Vladimir Yanover,
Accepted-Modified, Technical Binding
Accept the contribution with the following
changes:
1. Instead of "Length - Length of message information
within the iteration of N_NEIGHBOR in bytes" [which is not a regular
format element in 802.16] create a TLV that contains all needed fields
[which are PHY dependent]
2. In "HO Process Optimization" section
list network entry steps rather than related messages
3. State [in
Remedy part] that "Configuration Change Count" [of MOB-NBR-ADV] covers
also DCD/UCD parameters
4. Not clear why "DL Physical Frequency" [of
BS] is excluded. Is it a part of TLV Encoded Neighbor information?
5. Delete "TLV specific" [length of TLV Encoded Neighbor
information] which expalins nothing. "Variable" is enough. BTW it
appears in many places in the standard.
Document: C80216-04_146
Reply
Comment: from Mo-Han Fong, Accepted-Modifed, Technical
Binding
Add the information on service level
supported and available resource of the neighbor BS (refer to
contribution C80216e-04_224).
Document: C80216-04_144
Reply Comment: from Vladimir Yanover,
Rejected, Technical Binding
1. The contribution suggests non-contention
based MSS Initial Ranging. For that there must be a mechanism to
allocate UNICAST UL transmission opportunity for an MSS not having yet
Basic CID [e.g. using 48-bits MAC address]. Currently 802.16 lacks such
mechanism, so Remedy #1 cannot be implemented.
2. [Remedies #2-4] HMAC is a function of
AK, so success in processing of HMAC means that both sides probably use
the same AK. But it does not mean automatically that TEK state machines
at both sides are synchronized. This issue must be investigated more
thoroughly and probably more information must be exchanged to ensure
complete PKM synchronization between MSS and target BS
3. [Remedy #5] There is no relation between
establishment of IP connectivity [it is for management purpopses only!]
and transfer of network data from old BS to new BS and further to the
MSS
4. [Remedy #6,7] Language related to
network entry steps [rather than to specific messages] should be used.
5. For capabilities exchange: I didn't find
any analysis of situation when capabilities received over backbone do
not fit those of the MSS [e.g. because of transmission error or software
problem].
Document: C80216-04_144
Reply Comment: from Mo-Han Fong, Accepted-Modifed, Technical
Binding
HO Indication may not be required for non-contention based ranging
because the target BS must have known that the MSS is performing
handover, from the fact that the target BS sends a Fast_UL_ranging_IE to
allocate the UL resource.
I am sincerely dissappointed to be receiving Technical Binding
comments on a Consensus contribution that was widely distributed and
available for comment previously, with solicitation and no additional
comments for at least two weeks.
Thanks,
Phil