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Itzik,
Beacon can decrease the incidence of MSS needing to
Range Neighbor BS by providing Neighbor BS information like course measurement
air interface loading and QoS availability that can give MSS insight into
whether it should even be interested in hand-over to Neighbor BS. This is
in addition to providing physical channel information that can allow MSS to more
quickly find and scan Neighbor BS. Beacon's intent is to provide
additional information on a periodic basis to allow slow moving or immobile MSS
in a given geography (the majority of mobile devices in use usually fall into
these categories) insight into the Neighbor BS opportunities around
them without the MSS having to Scan, and especially without having to Range
Neighbor BS. Efficient mobile networks MUST avoid as much unproductive
Ranging as possible. If a Ranging event is not going to become a
hand-over, it is essentially unproductive and unnecessary overhead. To a
lesser degree, Beacon can also help reduce the time MSS spend unavailable to
Serving BS while MSS are Scanning Neighbor BS. MSS unavailable to Serving
BS impacts QoS so is less desirable structurally.
As far as replacing full sections in the current
document, in general I don't think I am espousing wholesale replacement.
My contribution 54 did have a lot of language changes, but it is clear that the
document needs a lot more clarity in its prose and most of the language changes
were clarification and extension, not the wholesale replacement of
concepts. Also, as we all agreed, the hand-over process definitely needed
work, and all of my other contributions only pertain to cleaning-up the
hand-over process.
Once again the primary function of my contribution
54 is to clean-up what is currently a messy hand-over process. When I say
messy I am referring to excessive, non-productive backhaul loading, Scanning and
Ranging; a poor mechanism for recovery from failed or discontinued hand-over
events; inadequate advantage taken of the many opportunities during hand-over to
correct for missed or failed steps and still have a successful soft hand-over;
inability to conduct a soft hand-over after MSS dropping from Serving BS (i.e.
hand-over without prior notification); etc....
Thanks,
Phillip Barber
----- Original Message -----
Sent: Tuesday, October 14, 2003 3:44
AM
Subject: RE: stds-802-16-mobile: Handoff
Ad Hoc group
Hello All,
First, let me say that I'm happy to see a discussion
going on.
Second, Phil, I may be missing something, but I don't
see how beacon message at the serving BS replaces Ranging at potential target
BSs.
Also
a general note, from my perspective, there are many ways to do a cretin
functionality, different ways does not mean that one is better than
other.
I
would have liked to see a process ,in which problems (or points of
improvements) in the current document are identified and handled.
I
prefer to avoid of replacement of full sections if this not fully
necessary.
Thanks,
Itzik.
Thanks for the input. I will look at
breaking the MOB_BEA_ADV message up and adjusting broadcast
timing to reduce impact on the air interface efficiency. Probably
make allocations over several non-consecutive frames optional. Can't
leave the Beacon hanging too long or it interferes with sleep-mode
activity. Probably no more than 16 total frames for Beacon
transmittal.
It is problematic to only transmit change
information in the TLV. On the one hand, it reduces overhead to only
transmit change information, and full TLV information is redundant to MSS
attached to the Serving BS. On the other hand, providing change
information TLV only impacts MSS attempting to gain information for
initial network connection, not hand-over. On reflection, since MSS
initial network connection is less timing sensitive, I would agree that
transmitting only change information in the TLV is appropriate and
efficient. I would say that we would likely need to transmit
entire/clean Beacons every 10th or 20th Beacon transmittal or so to provide
accurate and complete information to MSS that have connected to the Serving
BS in the interim between full Beacon messages and therefore do not have
basis information from which to evaluate change only TLV
information.
I remain convinced that the broadcast Beacon is
the way to go instead of using intrusive and unnecessary/constant Ranging of
adjacent Neighbor BS. Better to have a larger broadcast Beacon
eating-up downlink airtime every five seconds or so than a lot of
unnecessary and intrusive Neighbor BS Ranging. Might even look at
stretching the max interval threshold. 5 seconds might be an
unsupported tight window for static cases. Most mobile systems spend
the vast majority of their time in relatively static performance making
excessive mobility management overhead (too frequent Beacon broadcast in our
case) an unproductive burden. To be sure, for high mobility
environments with frequent hand-overs, 5 seconds or less between Beacon
broadcast may be optimal. But I think we should caution on the side of
more relaxed specificity on max interval and leave it to
the manufacturer to create appropriate Beacon broadcast timing
mechanisms.
Thanks,
Phillip Barber
----- Original Message -----
Sent: Tuesday, October 14, 2003 1:43
AM
Subject: RE: stds-802-16-mobile:
Handoff Ad Hoc group
Phillip,
As you stated in your document, the MOB_BEA_ADV msg is much too
large. I would suggest to make another effort here and maybe fragment the
message and transmit it is pieces. One possible cut is to have the
"header" portion (BS ID, Operator ID, Network Type etc.) along with some
of the slow changing info of the BEA_ADV TLV transmitted once in a while.
You may also consider transmitting the neighbor info in pairs and have the
entire message come up at the receptor side in a slower rate, but
consuming lower bandwidth off the link.
We all are looking forward to review your
contribution.
Ofer
I hope to have my contribution ready for
submittal to the reflector for peer review by the end of this
week. I look forward to your comments.
Thanks,
Phillip Barber
----- Original Message -----
Sent: Tuesday, October 14, 2003
12:38 AM
Subject: Re: stds-802-16-mobile:
Handoff Ad Hoc group
Dear Phillip Barber.
I would appreciate your effort on AdHoc
activities
I think we need a clean-up version including
your comments as followings and it would be good reference to peer
review your contribution..
Even I have a couple of comments on your
contribution, it would not be better at this point according to your
mail.
And I'd like to know your schedule when are
you going to distribute a clean-up version so that I can
have a chance to revise my comments
Thanks
Changhoi Koo
----- Original Message -----
Sent: Tuesday, October 14, 2003
6:29 AM
Subject: stds-802-16-mobile:
Handoff Ad Hoc group
Itzik,
Just wanted to drop a note and let the
Handoff Ad Hoc group know that I am--taking into consideration
Vladimir and your comments from Session 27 in Denver--re-working my
contribution number 54 into r4 of the current 16e document. I
hope to have my submittal ready for the reflector by the end of this
week for peer review.
Based on comments at Session 27, I plan
two changes to my contribution 54 proposal. First, For those
who wish to use Association as a mechanism to set initial power
settings for 6.2.9.5 Ranging instead of using the refined method
based on received signal characteristics interpreted during
dowlink/uplink synchronization as presented in the current iteration
of the 16d document, I plan to continue to include Association, but
as an optional, passive activity with application to
6.2.9.5. I will provide appropriate language. I had
previously espoused removal of Association in its
entirety. Second, I will clean-up my sleep-mode changes
to work with contributed changes as of Session 27. Itzik,
could you make a stab at providing my corrected formula and
send it to me for inclusion? I will also clean-up my hand-over
flow diagrams to reflect these changes, including your comments
regarding other-Target BS notifications.
Thanks,
Phillip
Barber
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