Re: [802.21] [Mipshop] Re: Architectural Considerations for Handover InformationServices (was: Re: CARD Discussion Query Discussion)
I think we are not arguing what is the right way to do HO. This is out of
scope of 802.21.
It is fair that certain HO may not need time-efficient access to
information. I think it is also fair that some other HO may need or want to
take advantage of time-efficient information access.
I don't know how many different HO scenarios, situations, in different
systems architectures, can be identified. It is unreasonable to believe that
we can exhaustively address them and conclude that non-time-efficient
information access is enough for the need of HO and mobility management.
Please allow be to restate what I said. It is OK that 802.21 decides to
develop IS for non-time-efficient information access; and in this case it
should be clearly stated so and it is up to whatever the HO and mobility
management mechanisms to decide whether such IS is needed.
> From: Srinivas Sreemanthula <Srinivas.Sreemanthula@NOKIA.COM>
> Reply-To: <Srinivas.Sreemanthula@NOKIA.COM>
> Date: Fri, 21 Oct 2005 09:42:51 -0500
> To: <STDS-802-21@listserv.ieee.org>
> Conversation: [802.21] [Mipshop] Re: Architectural Considerations for Handover
> InformationServices (was: Re: CARD Discussion Query Discussion)
> Subject: 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
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>
>>>>>
>>>>>
>>