RE: [802.21] [Mipshop] Re: Architectural Considerations for Handover InformationServices (was: Re: CARD Discussion Query Discussion)
Since you made a note about small devices, I wanted to express our
opinion coming from another small devices manufacturer.
If you did not do predictive fetching (say from WLAN) how can you ensure
that the current radio link conditions are good enough for a successful
IS query exchange? So it seems that the STA, anyway, must proactively
obtain the information while the current link is reasonably good. On the
other hand, handovers from cellular or other wide area networks with
terrestrial coverage, there may never be an impending handover scenario
to WLAN. But, these handovers are merely opportunistic, in the sense,
they take advantage of a higher bandwidth or a cheaper wirless system.
So you may fetch IS info and perform handover but it is not dictated by
strict latency bounds, IMO.
Also, for network controlled scenarios, it may be possible for STA to
sit on a few sets of IS info and wait for the command from the network
to say which one to use.
Regards,
Srini
>-----Original Message-----
>From: ext Qiaobing Xie [mailto:Qiaobing.Xie@MOTOROLA.COM]
>Sent: Thursday, October 20, 2005 4:56 PM
>To: STDS-802-21@LISTSERV.IEEE.ORG
>Subject: Re: [802.21] [Mipshop] Re: Architectural
>Considerations for Handover InformationServices (was: Re: CARD
>Discussion Query Discussion)
>
>I just want to emphasize a point Hong-Yon has made
>(repeatedly) - that the information in the DB is not dynamic
>of nature does NOT mean that the access to the information by
>the UE is not going to be time sensitive. The most common and
>sensible engineering approach for a small device that needs to
>access a DB is to fetch the needed info on-demand.
>Predictive-fetching is not an easy thing to do (one would need
>to have a good prediction algorithm) and duplicating the
>entire info on the device is simply impractical.
>
>regards,
>-Qiaobing
>
>Subir Das wrote:
>> Peretz,
>> I agree with your view. We do not expect that such information will
>> change with real time and during handover. Also as you have
>> mentioned, we are enabling handover decision process with
>the IS. The
>> major part of this handover process such as policy, network
>selection
>> , etc, are out of scope.
>>
>> -Subir
>>
>>
>>
>> Peretz Feder wrote:
>>
>>>On 10/20/2005 8:40 AM, Hong-Yon Lach wrote:
>>>
>>>
>>>>I have heard examples in which I would consider the information as
>>>>dynamic, such as the "neighbouring network/access points
>available that match ..."
>>>>
>>>>
>>>
>>>neighboring info could change every few hours indeed, but
>wouldn't you
>>>agree it is considered static for an HO process that should
>be in the few msec range?
>>>
>>>
>>>
>>>>and examples in which the information is very static (does
>not change
>>>>much with time).
>>>>
>>>>The dynamic nature of information, depending on the
>specific piece of
>>>>information, could be different according to deployment, and could
>>>>change over time.
>>>>
>>>>
>>>
>>>Yes and even every few hours is good enough to be labeled static.
>>>
>>>
>>>
>>>>When IS is used in the preparation of handover, it would be nice to
>>>>minimise such preparation time, because the longer it is the more
>>>>likely the risk of losing current network coverage and making
>>>>handover less seamless. Maybe IS is not meant to be used in
>such context?
>>>>
>>>>
>>>
>>>That is my understanding, which I expressed in many f2f
>meetings w/o much objection.
>>>
>>>
>>>Anyway, it will be a good step
>>>
>>>
>>>>forward to know what we are assuming/doing/enabling and
>what we are not.
>>>>
>>>>
>>>
>>>We are enabling the decision process, wherever it is located to be
>>>equipped with all the pertinent info for a HO proper decision. this
>>>includes policy, neighbors, provisioning, loading, etc.
>>>
>>>
>>>
>>>>Yoshihiro has given example about
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>>From: Peretz Feder <pfeder@lucent.com>
>>>>>Organization: Lucent Technologies
>>>>>Date: Thu, 20 Oct 2005 08:10:54 -0400
>>>>>To: Hong-Yon Lach <hong-yon.lach@motorola.com>
>>>>>Cc: <STDS-802-21@listserv.ieee.org>
>>>>>Subject: Re: [802.21] [Mipshop] Re: Architectural
>Considerations for
>>>>>Handover InformationServices (was: Re: CARD Discussion Query
>>>>>Discussion)
>>>>>
>>>>>
>>>>>
>>>>>On 10/20/2005 5:00 AM, Hong-Yon Lach wrote:
>>>>>
>>>>>
>>>>>
>>>>>>Apparently, we still have very different ideas in mind
>when we talk
>>>>>>about IS concerning what it is. A lot of discussions so far
>>>>>>concerns how it should be supported. Peretz, I think you pointed
>>>>>>out the consequence that we can only disagree about the
>assumption of IS.
>>>>>>
>>>>>>
>>>>>We are not agreeing on its dynamic nature. The rest we do.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>How IS is to be used and should be supported depends on what
>>>>>>information IS is dealing with. If we do not have
>consensus on the
>>>>>>nature/type/purpose of information to be coped with in
>IS, I don't
>>>>>>see how 802.21 can produce a requirement on IS and how
>MIPSHOP knows what it is doing for IS.
>>>>>>
>>>>>>
>>>>>IS is dealing with all the relevant info that can assist the HO
>>>>>decision. To assume that in a middle of a few msec hanodoff the IS
>>>>>DB can be queried for pertinent HO info. and exchange all of that
>>>>>over L3 is a very loaded assumption, as it assumes that the IS DB
>>>>>will be updated at such resolutions and its info be
>relevant to a a
>>>>>few msec process.
>>>>>
>>>>>
>>>>>Your bleak statement is not so black and white. IS info is
>relevant
>>>>>and can be very well defined but it is not dynamic in nature.
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>>Cheers,
>>>>>>Hong-Yon
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>>From: Peretz Feder <pfeder@LUCENT.COM>
>>>>>>>Organization: Lucent Technologies
>>>>>>>Reply-To: Peretz Feder <pfeder@LUCENT.COM>
>>>>>>>Date: Thu, 20 Oct 2005 01:03:18 -0400
>>>>>>>To: <STDS-802-21@LISTSERV.IEEE.ORG>
>>>>>>>Subject: Re: [802.21] [Mipshop] Re: Architectural Considerations
>>>>>>>for Handover InformationServices (was: Re: CARD Discussion Query
>>>>>>>Discussion)
>>>>>>>
>>>>>>>On 10/18/2005 6:11 PM, Qiaobing Xie wrote:
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>Yoshihiro Ohba wrote:
>>>>>>>>...
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>- In reality, 3GPP2 has XML-based method (e.g., XCAP) in its
>>>>>>>>>dependency list.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>If I remember it right XCAP/XML is used there for
>maintaining the
>>>>>>>>address book/buddy list that sort of things. I can imagine that
>>>>>>>>sort of events only happen at most no more than a few
>times a day
>>>>>>>>for any given user and probably only happen when the
>user is NOT
>>>>>>>>in a call. In contrast, IS query/response likely will
>be part of the h/o call flow...
>>>>>>>>
>>>>>>>>
>>>>>>>You are assuming IS is a dynamic information that can influence
>>>>>>>Handover per the IS query response. Many .21 members do
>not agree
>>>>>>>with this position. IS should be treated as static information
>>>>>>>that is provided to the HO decision entity in advance.
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>
>>>>>>>>regards,
>>>>>>>>-Qiaobing
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>>>Yoshihiro Ohba
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>>>>>>
>>>>
>>>>
>