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Re: stds-802-16-mobile: Handoff Ad Hoc group



Dear All..
Basically I agree with Itzik's view..
I think that current document does not have any critical problem and unclear operation about handover...And I don't see any benefit and enhancement from NBR-ADV message...
 
As you proposed, the NBR-BEA-ADV message may be useful to assist the handover, However, I think there is one thing for that message....
Because the NBR-BEA-ADV message containing neighbor list BS's information (QoS, BW and so on) should be updated very quickly(nearyl real time and in line with the neighbor BS) according to the nieghbor list BS environment to notify the recent information to the MSS, it could be increased that the BS exchanges its message through the backhaul network. As result it could make overload on the backhaul network and air interface...And also, If the information sent by NBR-BEA-ADV is not recent information, the scanning by the MSS could  not be useful and give an unpredictable operation..
 
Thanks
Changhoi Koo
----- Original Message -----
Sent: Wednesday, October 15, 2003 12:41 AM
Subject: Re: stds-802-16-mobile: Handoff Ad Hoc group

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.
-----Original Message-----
From: owner-stds-802-16-mobile@majordomo.ieee.org [mailto:owner-stds-802-16-mobile@majordomo.ieee.org]On Behalf Of Phillip Barber
Sent: Tuesday, October 14, 2003 09:26
To: Ofer Kelman; stds-802-16-mobile@ieee.org
Subject: Re: stds-802-16-mobile: Handoff Ad Hoc group

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
-----Original Message-----
From: Phillip Barber [mailto:pbarber@broadbandmobiletech.com]
Sent: 14 October, 2003 7:52 AM
To: Changhoi Koo; stds-802-16-mobile@ieee.org
Subject: Re: stds-802-16-mobile: Handoff Ad Hoc group

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