Subject: RE: [Mipshop] Re: Architectural Considerations for Handover InformationServices (was: Re: CARD Discussion Query Discussion)

From: "Singh Ajoy-ASINGH1" <[email-masked]>
Date: Fri, 14 Oct 2005 11:11:42 -0400

Hi Michael, 

I think the issue of TLV and XML was discussed during 802.21 meeting.
But it appears to me that more folks supported the idea of TLV in last
802.21 meeting. I guess there was straw poll as well. Do you have any
result of straw poll? It may be good data point about 802.21's view
about XML versus TLV. 

Regards,
Ajoy 

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On
Behalf Of [email-masked]
Sent: Thursday, October 13, 2005 6:38 PM
To: [email-masked]; [email-masked]
Cc: [email-masked]; [email-masked];
[email-masked]; Petrescu Alexandru-AAP021
Subject: RE: [Mipshop] Re: Architectural Considerations for Handover
InformationServices (was: Re: CARD Discussion Query Discussion)

 Colleagues,

A couple of points regarding the issue of chartering / standardizing for
FMIP needs, and getting .21 & MIPSHOP to work together...

We are at the draft stage in 802.21 and need proposals to modify the
draft.

.21 is counting on the solution in the IETF to be
compatible/interoperable with the IEEE solution. Sorry to be so high
level on that statement.

.21 requires an IS solution that solves problems for more than just
FMIP.

Perhaps the issues of IE representation and query language can be
separated to some degree? For example, if an alternative query language
exists today that would be useful, could it be used against the XML
representation?

.21 has expressed needs for extensibility and flexibility. The approach
of schemas and dynamic semantic agreements is one way to enable those
traits.

The issues of bandwidth & latency have been raised in both fora, but do
we have the empirical support for both sides of the issue?

Best Regards,
Michael

-----Original Message-----
From: [email-masked] [mailto:[email-masked]] On
Behalf Of ext James Kempf
Sent: Thursday, October 13, 2005 3:58 PM
To: Yoshihiro Ohba
Cc: [email-masked]; [email-masked]; Rajeev Koodli;
Petrescu Alexandru-AAP021
Subject: [Mipshop] Re: Architectural Considerations for Handover
InformationServices (was: Re: CARD Discussion Query Discussion)

> It is obviously more hard and inefficient for the client to process 
> high volume of raw data provided by the networks to extract a piece of

> information in which the mobile is interested and choose an 
> appropriate network, than to construct a semantic query to retrieve 
> only necessary information it is really interested in.  The raw data 
> can be order of hundred kilobytes if there are 10 MAC types each has 
> 20 or more neighboring point of attachments each advertising hundreds 
> of bytes of information and most of the data could be just garbage and

> for the client and it is wastful in terms of both bandwidth and 
> processing resources.  If the mobile is moving at a high-speed, then 
> information on "neighbors of neighbors" needs to be obtained to 
> proactively make handover decisions, then the information volume can 
> be more.
>

But at 100 Mbps (802.11n speed) 100K is just  1 msec. Even at 11 Mbps,
its still only 100 msec. if there's no contention for the link. It's
just not a problem with today's bandwidths, IMHO. We're not talking
about 9.6 kbps links anymore. And I'm not saying that there should be no
query language, just that it should be simple.

>> Since I don't think typical users want to be bothered with specifying

>> the details of querying for handover services information, it seems 
>> that automatic query construction would be required. Most users want 
>> some kind of symbolic or summary information, if they need to be 
>> involved in an intertechnology handover decision.
>
> I believe automatic query construction can be made for any query 
> methods.
>

Well, I know (from having implemented it with SLP) that it is hard. It
is much easier to haul over what you need and process it locally. What
happens is the query typically ends up getting stuff you don't want
anyway, regardless of how careful you are in constructing it, so you
typically need to postprocess anyway. So why bother to have all the code
and complexity of trying to do the automatic query construction?
Application developers then don't bother to use the complex query
language, so you end up having this substantial chunk of code in the
protocol processing that isn't used most of the time.

>>
>> It is much easier to just ask for the available information, then do 
>> the processing on the client. I can't see the amount of information 
>> on handover services being so large that it would be unreasonable to 
>> send over the wireless link, especially given the trend toward 
>> increased bandwidth.
>>
>> >>I actually mean "using complex query semantics" not "full text". 
>> >>Systems
>> >>with complex query semantics in the network haven't been very 
>> >>successful in the network information services area. For example, 
>> >>DNS has very simple query semantics. LDAP has very complex query 
>> >>semantics. People prefer DNS.
>> >>Query semantics is naturally not the only reason why they prefer 
>> >>DNS, of course, but having complex query semantics has not proved 
>> >>such a compelling attraction to motivate people to use LDAP for 
>> >>directory services instead of DNS (though LDAP was for a time 
>> >>considered to be a possible successor to DNS). There are other 
>> >>examples I could cite, and I don't think we need to get into a 
>> >>debate here about this particular example. For this reason, I 
>> >>believe that having a simple query semantics, using keywords or the

>> >>like, is a better solution than complex queries.
>> >
>> >I believe a solution depends on the detailed requirements on the 
>> >service provided by it, not directly on the area the service belongs

>> >to.
>> >
>>
>> I'm not sure I understand your point. What do you mean by "the area 
>> the service belongs"?
>
> I mean the area of network information services.
>
> BTW, I think this kind of discussion should be done in 802.21 where 
> Information Service for heterogenious handovers is being defined.
>

No, it needs to be done here too. You're claiming that you want an XML
protocol with complex query language. I disagree, based on my experience
with SLP and LDAP, that this is really any value in a system-level
application like network information services. Regardless of what 802.21
wants, we need something that provides network information for FMIP, and
if we are going to try to get the two applications to work together, we
need to come up with a protocol that satisfies both.

Anybody else have an opinion?

            jak 

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---

From: Subir Das <[email-masked]>
Date: Fri, 14 Oct 2005 16:59:21 -0400

Why are we discussing .21 straw poll here?  I think we are not 
addressing the point
that Mipshop chairs wanted to know from .21 folks about their charter 
(in particular
.21 related text). Instead, we are discussing many other things that are 
not very
relevant at this stage, IMO.  I think  Michael Williams, vice chair of 
.21 has nicely
stated the 802.21's objectives. I agree with him and to me  also the 
scope of  .21 IS 
is broader than any specific mobility protocol related IS.     

Regards,
-Subir