Mapless GPS

[Carl Snellman]

Hey Stroller,

> I _really_ want to see an Openmoko application where you can just choose a
> contact and have your position sent to them by text message. When their
> Freerunner receives the message it automagically opens a GPS application
> that points to your position - this would be SO useful for meeting up with
> friends, finding a party or a bar or whatever, joining them at a deserted
> picnic spot in the woods. I wrote about this before
> <http://lists.openmoko.org/pipermail/community/2008-April/016318.html> and I
> see no need for something more complicated than a "GPS compass" display like
> this.


Just FYI, I'm actually in process of registering well-known SMS ports
for this purpose with IANA, so that interoperability between devices
would be facilitated. If we get the registration through, there would
be two known ports: port X for receiving someones location, and port Y
for receiving a location request from someone.

Below is the email I originally sent to IANA. All comments are welcome!

I also though about getting TCP/UDP ports registered for the same
purposes, but there the biggest problem is identification and
authentication of the sender. With SMS, MSISDN can be quite reliably
used for identifying the sender, but no such identifier exists in
TCP/UDP world. Let me know if you have any ideas/comments on this!

Carl Snellman
Nokia, Inc.

---------------
> Dear recipient,
>
> I'm writing on behalf of JSR293 Expert Group, which is currently
> defining a new Java specification "JSR293 Location API 2.0" [1] under
> Java Community Process (www.jcp.org). This specification defines an
> API for java apps to access various location based services, such as
> mapping services, navigation services and geocoding/reversegeocoding.
> As part of the specification we have defined a standardized format for
> exchanging Landmarks (also known as Points-of-Interest, POIs.
> Landmarks are whatever information tagged with geospatial
> coordinates). This message format may be used by any app/system on any
> platform; it is not tied to Java alone.
>
> Now, in order to enable good interoperability between (mobile)
> devices, we would like to register some known ports so that whenever a
> message arrives in this known port, a handler can process the message
> as appropiate (for example, by showing the landmark on top of a map).
> I have investigated using SMS as one of the message bearers, and I was
> trying to find information how to officially register an SMS port for
> this use. I found on some sources (eg. [2]) that IANA is the one who
> registers the SMS ports on the reserved number space (0-15999 for
> 16-bit addressing scheme). We would want to register two ports on that
> range for two purposes:
> 1) the first port X would be dedicated to incoming location messages.
> The messages must be in the Landmark Exchange format as specified in
> JSR293 specification.
> 2) second port Y would be dedicated for incoming location requests.
> The TP-User-Data field may be empty, or contain user-generated
> message; the fact that this message was received in the dedicated port
> identifies it as a location request. Location request SMS is sent by
> someone who wants to get to know your location (formatted in landmark
exchange format).
> The sender is identified by the sender MSISDN. When a user receives a
> location request, the handler will prompt the user (or based on trust
> policy, will respond to request automatically) whether the user wants
> to response her/his current location. If so, the device performs
> positioning and then response is sent back to sender's MSISDN/port X.
>
>
> Thank you,
>
> Carl Snellman
> Member of JSR293 Expert Group
> Nokia Corporation
>
>
> -----------------------------
> [1] JSR293 Location API v.2.0 specification, available at
> http://www.jcp.org/en/jsr/detail?id=293, latest version (currently
> 0.18) available upon request.
>
> [2] ETSI TS 100 901 V7.5.0 (2001-12) Technical Specification Digital
> cellular telecommunications system (Phase 2+); Technical realization
> of the Short Message Service (SMS) Point-to-Point (PP) (3GPP TS 03.40
> version 7.5.0 Release 1998)