On Apr 17, 2012, at 5:41 PM, "Rosen, Brian"
<[email protected]<mailto:[email protected]>> wrote:
We recognize that there will be many databases, and the discovery problem is to
find the right "one" where one is in quotes because there could be more than
one suitable database.
Agree. When you say the right "one", how does the device know that in the
first place?
Some systems may not need discovery - some clients can be hardwired to a
server. Mobile clients probably can't do that if they can roam internationally.
When you say mobile client, are you considering "Fixed/Mode II WSD" or
"Slave/Mode I WSD" or both?
In case of "Fixed/Mode II WSD", what is the model? Can it roam without a
roaming relationship?
So there are a couple of inputs to discovery:
a) Location. This has to allow location as arbitrary lat/lon; you may not know
what country you are in. This is the device, not the human. The human may
know, the device may not. Some databases may cover the entire country, others
may cover a region. Sometimes location is known by a street address, and you
can know what country you are in.
b) Type of device. In every country, there are different classifications of
devices that may depend on band, power, portability, antenna characteristics…
So far, what we see is enumerated types per country, but I could imagine more
complex things. If the device doesn't know what country it is in, it may need
to do discovery in a couple of steps, the first of which identifies the
country, and then what type of device.
How does the Mobile client know the location? Do we assume GPS? What if it
is inside the building?
Discovery then is type and location in, device URI (not IP address I think) out.
LoST (RFC5222) is ideal for this. You pass location and a "service urn" in,
and you get a URI out. The service urn would contain the type. It has a
"forest guide" scheme that links LoST servers together kind of like DNS without
a root.
Brian
On Apr 17, 2012, at 5:26 PM, Das, Subir wrote:
During PAWS session in Paris IETF, there were a lot of questions/discussions on
'Discovery' of Database. It was not clear to me except if we are talking about
"Database Server Discovery", in particular, the domain name or the IP address
of the 'Server" that is hosting the database. OTH, I felt that some folks may
have different views and they would possibly like to see more features than
just discovering the domain name or IP address of the "Database Server".
In some offline discussions, I was told that it may be similar to what LOST
(RFC 5222) has defined. I read the LOST protocol and associated architecture
and my current understanding is that the LOST use case is different than what
we are trying to achieve via PAWS. Here is my understanding of the operating
model of PAWS interface (when defined):
-"Fixed/Mode II WSD" (per figure 1,<draft-das-paws-protocol-01>) can only query
the database
-The manufacturer of the "Fixed/Mode II WSD" may be different than
owner/operator of this device
-"Fixed/Mode II WSD" is certified by the regulatory body of the region that
they serve
- Either the "Fixed/Mode II WSD" device operator or the device vendor has an
a-priori relationship with one or more covering database administrators. This
relationship
is utilized to either configure or enable the discovery of the proper database
to contact in the current location
I would like to know the group's view of the above model. To me, finding the
emergency services or restaurant information near my location is different than
getting to know a server that can provide me with channel/frequency/power and
other information in the location where "Fixed/Mode II WSD" is situated. In
addition, emergency services do not require a subscription and the service is
mandated by the Government/regulatory bodies. Some may argue that 'White Space'
service may be free as well, but to my understanding it is not quite the
similar model as emergency services.
I hope with this thread we can clarify/understand the discovery issue.
Regards,
_Subir
_______________________________________________
paws mailing list
[email protected]<mailto:[email protected]>
https://www.ietf.org/mailman/listinfo/paws
_______________________________________________
paws mailing list
[email protected]
https://www.ietf.org/mailman/listinfo/paws
