Ajay Rajkumar
wrote:
Hong-Yon,
I agree that SAP is defined to provide an abstraction between a service provider
entity and a user entity.
Also, MIH protocol would be used to provide communication between the two
MIHF entities.
The problem arises from the current text in the draft in Section 5.6
"Upper layers may directly send commands to MIHF. Similarly MIHF entity may
also
send commands to another remote (peer) MIHF entity. Primitives corresponding
to all these services
described above are within the scope of MIH_SAP."
[Vivek
G Gupta]
This
text can be updated. Below is a suggestion for the second part of this paragraph
in section 5.6 (pg 29 of draft D01.09)
“The
MIH_SAP and associated primitives provide the interface from MIHF to the
upper layers of the mobility-management stack. Upper layers need to register
with MIHF as users to receive MIHF generated events and also for link layer
events that originate at layers below the MIHF but may be passed on to upper
layers through MIHF. Upper layers may directly send commands to MIHF.
Similarly MIHF entity may also send transport these
commands and events to another remote (peer) MIHF entity. Primitives
corresponding to all these services described above are within the scope
of MIH_SAP. The
L2 transport functions are provided by media specific SAPs. The L3 transport
functions may be provided by other higher layer services.”
I
don’t see the need to introduce another SAP for these transport functions.
This implies that MIH_SAP is being used both by the MIH User as well as
MIHF to communicate with the remote entity, which is my view is incorrect.
[Vivek
G Gupta]
MIHF
does not use MIH_SAP. That notion is indeed incorrect.
The
first sentence in paragraph above (copied below) illustrates that clearly
as well.
“The
MIH_SAP and associated primitives provide the interface from MIHF to the
upper layers of the mobility-management stack”
Regards,
-ajay
Hong-Yon Lach wrote:
Salut all,
A SAP is defined to provide an abstraction of service between a service provider
entity and its user entities in the local system. A protocol provides a specification
of interactions and operations between “peer” entities in different (sometimes
virtual) systems with well-defined PDUs exchanges over a communications transport.
If a local MIH-user needs a remote services by a remote MIHF, it makes its
request to the local MIHF through the MIH SAP. The local MIHF determines
that it needs the support of a remote MIHF, it thus performs the necessary
operations with the remote MIHF using the MIH protocol. Upon the end of the
MIH protocol operation, the local MIHF provides a response to the MIH-user
via the MIH SAP.
An entity can initiate the execution of its function and/or protocol by
many different triggers: timeout of a timer, request by its users, detection
of certain system conditions, reception of a PDU from its peer, etc. The
entity can initiate its function and/or protocol without going through its
SAP. A SAP is not the only means to have its serving entity to initiate a
function and/or protocol.
I hopes this addresses your concerns.
Cheers,
Hong-Yon