RE: [MIHEP] RE: [802.21] Discussion on transport protocol selection for MIH!
Compare how some intra-technology handovers are done in some of our supported technologies, with the handover request having piggyback on it a list of BS/PoA's.
Perhaps a new inter-technology handover request in the MAC/link layer with a mixed list of target PoA's drawn from those maintained by the admin/operator of the interworked networks would be an possible?
BR,
Michael
-----Original Message-----
From: owner-stds-802-21@ieee.org [mailto:owner-stds-802-21@ieee.org] On Behalf Of ext Stefano M. Faccin
Sent: Tuesday, July 19, 2005 11:38 AM
To: STDS-802-21@listserv.ieee.org
Subject: Re: [MIHEP] RE: [802.21] Discussion on transport protocol selection for MIH!
Vivek,
good points. Please see below.
Stefano
--------------------------------------------------------------------------------
> Given the wide coverage of cellular and wimax networks the
> issue/problem often turns out to be, how to detect the presence of wifi and how to decide to switch over to wifi?
> In the below case seems like the Information Service may not be very
> helpful in detecting the presence of wifi anyway. Seems like you may
> have to detect presence of wifi by traditional (beacon scan/probe)
> means anyway, unless the cellular network can give you some hint about
> presence of a wifi hotspot. And again after detecting the presence of
> wifi you may have to resort to L2 to pull up information pertaining to appropriate network selection.
[Stefano] yes, this is indeed possible.
> In general during discussions in 802.21, some of the requirements that
> emerged are as
> follows:
> 1] Need to enable both L2 and L3 transports
> L3 may be primarily used for 3G networks (where it is more difficult
> to modify L2 in a timely manner). L2 enabling in case of 802 networks
> is relatively less difficult and needed in certain cases.
[Stefano] indeed, though one can also use L3 transport also for the 802 scenario, e.g.
for 802.11 to enable the handoff from outside network and different technologies to the
802.11 APs in the enterprise while using legacy (i.e. non-802.21 enabled) APs.
> 2] 802.21 defines the payload in both cases (both for L2 and L3
> transports) for MIH services. This should work for different MIH users
> including different L3 and above mobility protocols as well.
> 3] Other requirements for L3 transport:
> a] How do you discover the presence of MIH services (IS, CS, ES etc.)
> and capability at L3?
[Stefano] good question. I believe this would have to be addressed by IETF with the help of 802.21
> b]Any security considerations
[Stefano] this is indeed one of the "architectural" issues of using L3 transport for 802.21, and IETF is better positioned to define a solution for this (or re-use existing solutions). 802.21 can help with the definition of precise requirements and scenarios.
> c] If an IP based transport is used we may need to select appropriate
> port numbers if we end up selecting different protocols for carrying
> (IS,CS,ES) payloads. Not sure if we need much else beyond this:
[Stefano] the port numbers are definitely eneded. You also need an actual protocol to carry the 802.21 payload and you need to solve the architectural issues such as discovery and security. Not sure why you say there isn't much more to do.
> BR,
> -Vivek
> -----Original Message-----
> From: Koora Kalyan Com Bocholt [mailto:kalyan.koora@siemens.com]
> Sent: Tuesday, July 19, 2005 12:11 AM
> To: Singh Ajoy-ASINGH1; Gupta, Vivek G; 'STDS-802-21@listserv.ieee.org'
> Cc: mihep@eng.monash.edu.au
> Subject: AW: [802.21] Discussion on transport protocol selection for MIH!
>
> Hi Ajoy,
>
> let me put up an other scenario where it is also not possible to get
> information over higher layer.
> Let us assume you have an IP connection over a cellular interface like
> 3GPP and your in a foreign country. You come up to a hotspot where you
> don't have any knowledge of the ISPs over there. Further, it is
> possible that some come up and some go down time to time. In this case
> how does the cellular provider knows about the hotspot? Or do you
> assume that all the ISPs at hotspots do have some agreements with the
> cellular ISP? Some of them could be just 'local' ISPs using
> firewall/NAT/masquerading techniques and are not interested in cellular providers.
> In this case too, you may have the possiblity to handover to the
> hotspot ISP if you find any suitable provider.
>
> Regards,
> Kalyan
>
> -----Ursprüngliche Nachricht-----
> Von: Singh Ajoy-ASINGH1 [mailto:ASINGH1@motorola.com]
> Gesendet: Montag, 18. Juli 2005 17:07
> An: 'Gupta, Vivek G'; Koora Kalyan Com Bocholt;
> 'STDS-802-21@listserv.ieee.org'
> Betreff: RE: [802.21] Discussion on transport protocol selection for MIH!
>
>
> [Gupta, Vivek G]
> Actually the difficulty is for the first time, when you are powering
> up or in an un-initialized state or don't have any of the links
> connected. At that time which initial link to select may be an issue.
> But then you could always have a default radio/link to use in such
> cases.
>
> Ajoy-> Yes, but that is initial call setup scenario. Do we really need
> Ajoy-> any seamlessness during initial call setup?
>
> -----Original Message-----
> From: Gupta, Vivek G [mailto:vivek.g.gupta@intel.com]
> Sent: Sunday, July 17, 2005 9:45 AM
> To: Singh Ajoy-ASINGH1; Koora Kalyan Com Bocholt;
> STDS-802-21@listserv.ieee.org
> Subject: RE: [802.21] Discussion on transport protocol selection for MIH!
>
>
>
> > -----Original Message-----
> > From: owner-stds-802-21@ieee.org [mailto:owner-stds-802-21@ieee.org]
> On
> > Behalf Of Singh Ajoy-ASINGH1
> > Sent: Sunday, July 17, 2005 6:36 AM
> > To: 'Koora Kalyan Com Bocholt'; 'STDS-802-21@listserv.ieee.org'
> > Subject: RE: [802.21] Discussion on transport protocol selection for
> MIH!
> >
> > Hi Kalyan,
> >
> > I would like to comment on one of your statement here.
> >
> > Regards,
> > Ajoy
> >
> >
> > If we select higher layer protocols (eg. layer 3), it is
> > difficult for the IS to be delivered before a generic layer
> > related connection is established (if we consider IP, then
> >
> > Ajoy-> If you have multi-link mobile, you can use IP transport of
> > connected link to obtain information about neighboring link.
> [Gupta, Vivek G]
> Actually the difficulty is for the first time, when you are powering
> up or in an un-initialized state or don't have any of the links
> connected. At that time which initial link to select may be an issue.
> But then you could always have a default radio/link to use in such
> cases.
>
>
>
>
> >