Re: [802.21] Discussion on Information Service
Hi, Ulises,
Please see my comments in-line.
regards,
-Qiaobing
Olvera-Hernandez, Ulises wrote:
> ... So far my assumption is that 802.21
> will strive to provide, at least, any handover information that is not
> already covered amongst existing wireless technologies.
I'd say this is a very ambitious goal.
Firstly, mobility (handover) management is a hot topic in many stds
bodies (e.g., IETF, 3GPP, WiMax, etc.) and new ideas and ways for MM
emerge constantly. Some information that may seem irrelevant to handover
today may become relevant tomorrow. It would be very hard to clearly
identify such a set of handover information as you suggest above.
Secondly, even if we can identify such an information set, it may
consist of information from different layers and parts of the network.
Since 802.21 MIH has a particular architectural position of its own in
the stack (as shown in our various reference models), are we sure that
architecturally 802.21 MIHF is the right entity/mechanism to play the
role of the overall fetcher, aggregator, and deliverer of all handover
information?
Would it be more practical if we assume that central role of 802.21
MIHF, due to its architectural position, is the fetcher, aggregator, and
deliverer of *lower layer* (PHY, MAC) handover information across
different interfaces? In addition, **IF** some other network information
that is useful for handover AND is *convenient* to be handled by 802.21
MIHF, then we would consider to include it.
> If this is everyone's understanding, then this would mean that although
> 802.21 might not be the sole provider of handover information, 802.21 is
> indeed the "piece of the puzzle that was missing".
> If we agree with this assumption, then we need to provide a
> comprehensive set of IE that can cover the existing needs.>
Do we all know what the "existing needs" are?
>
> Therefore, even after we agree that an IE is useful for
> handover, we have to ask ourselves why 802.21 is the right mechanism to
> carry/provide this IE to the h/o decision logic.
>
> <(Ulises Olvera) We discussed this issue a while ago and I believe we
> agree that although some handover information might be available by
> other means (e.g., System Operator Codes, Network usage cost,
> Neighboring Maps, Signal Quality Indications,etc), providing a uniform
> interface towards 802.21/MIH users does add value. However I do agree
> that the selection of applicable IE needs to be justified, e.g., as
> suggested below, through explicit use cases. This will prove
> particularly important when is time to go to other standards bodies and
> we try to justify why and how 802.21 can add value on top of the
> existing mechanism.
>
ditto.