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Re: [802.21] question on MIH event subscription



Hi, Yoshi,

I would think so. On the surface it may seems to be an inconvenience
(one more step for the IS client). However, if you think about the
actual implementation, it is a big help:

- You (as the local MIHF) generate a MIH_Get_Information.indication when
you receive a MIH_Get_Information response from a peer MIHF.

- If you only have one MIH User above you, it is quite simple - you
invoke the MIH_Get_Information.indication to that MIH User.

- But it becomes interesting if you have more than one MIH Users above
you. You have the following options:
  1) invoke a separate MIH_Get_Information.indication to each one of
them. But this could be very unnecessary since some of your MIH Users
may have nothing to do with Info Service.
  2) invoke the MIH_Get_Information.indication to the MIH User who
originally initiated the IS query - this is a much better design. The
only limitation is that you will not be able to have one MIH User as the
querier and different MIH User as the IS response handler.
  3) use event subscription and only invoke
MIH_Get_Information.indication to whichever MIH User(s) who has
subscribed the event.

To me 1) is unacceptable, 2) is ok, 3) is both efficient and flexible
and consistent with event subscription/notify model.

And we really want, we can even combine 2) and 3) - if no one subscribes
the event, then we dispatch a MIH_Get_Information.indication to the
original querier.

regards,
-Qiaobing

Yoshihiro Ohba wrote:
> Hi Qiaobing,
> 
> I am a slow starter to follow this thread :)
> 
> What about MIH_Get_Information indication for Information Service?  Is
> it also considered as an MIH event and event subscription is needed
> for it?  
> 
> Yoshihiro Ohba
> 
> 
> On Thu, Mar 01, 2007 at 11:40:22AM -0600, Qiaobing Xie wrote:
>> All,
>>
>> I think the following statements should be true:
>>
>> - any MIH .indication primitive shall be considered an MIH event
>> - an MIH User shall be notified about an MIH event only that User has 
>> explicit subscription for the event
>>
>> Therefore, we will need to accept the following scenario as perfectly 
>> normal:
>>
>> 1. An MIH User invokes MIH_Configure_Link and sets some threshold in 
>> order to get a link report when that threshold is crossed;
>>
>> 2. But he forgets to (or intentionally does not) explicitly subscribe 
>> MIH_Link_Parameters_Report.indication event;
>>
>> 3. When the event happens, the User will not get the indication.
>>
>> My reasoning is that one may want to build a User whose responsibility 
>> is just to set link thresholds but the responsibility for receiving and 
>> processing the events are delegated to a different User (or Users). The 
>> latter will subscribe for the event but not the former.
>>
>> regards,
>> -Qiaobing
>>
>