1. HTTP Enabled Location Delivery (HELD)
draft-winterbottom-http-location-delivery-01
J. Winterbottom, M. Thomson, M. Dawson
IETF-63
19/09/2018

2. Rationale
Location information (LI) belongs to a specific IP device (Target)
LI is an access network service
A LS servicing an access network is able to determine LI for an IP device
Serve location information:
directly to the Target
to location recipients using a location URI
The point to note here is the clear delineation of responsibility – an access provider is responsible for providing location information. A device may assist in that, but the access provider is ultimately answerable. The access provider is in a unique position to be able to determine location information.
Location URI
IETF-63
19/09/2018

3. Application layer protocol
Preserve PIDF-LO format
Extensions do not affect the HELD payload
Traverses routers and NAT
Reliant only on the presence of IP
Common location request protocol
Type of access network has no effect
Application layer security
TLS with encryption and authentication
TLS satisfies Req. 4 (transmission security), 5 (key establishment), 13 (authentication – in combination with OCSP) and 14 (auth, integrity, confidentiality, replay protection – although this statement applies to the LO directly).
Location URI
IETF-63
19/09/2018

4. Privacy LI is associated with a device, not a user
Unlinked pseudonyms for the device
LI can be granted without identity information
Target provides a ruleset for LR requests to the LS
Based on common policy – flexible
The target may also specify what rules are included in served PIDF-LO documents
We can’t determine where a person is based on the location of an antenna or device that they own. Also, think about the model used for location within current phone networks – the phone number is used as the identifier, not the name of the owner of the phone.
The rules are associated with a device session and are not revealed to the LR. The identity of the rule creator isn’t necessarily revealed, even to the LS.
Point 1.1 – unlinked pseudonyms satisfy Req. 12
Point 2 – Req. 7
Point 2.2 – the target specifies two sets of rules: the viewer rules (part of the PIDF-LO template – the subset of rules specified in Req. 9 of RFC 3693) and the LG/LS rules (the full ruleset).
Location URI
IETF-63
19/09/2018

5. Basic request HTTP GET to retrieve LI HTTP POST with parameters
PIDF-LO – provide own location
Ruleset – by-value or by-reference
Specify the type of location or request location by-reference
Set a limit on response time
Location URI
IETF-63
19/09/2018

6. Location update Target publishes location update URI
A target may use GNSS in a similar fashion.
Target publishes location update URI
LS serves a request from LR
LS contacts target through update URI, which initiates positioning in cellular network to determine LI
Location URI
IETF-63
19/09/2018

7. “On Behalf Of” An entity that requests as if it were the target device
Acknowledgement that not all devices are able to determine or request LI
Enables delivery of services based on location for all devices
Emergency calls
Trust arrangement is either mandated by regulations, or as part of a contract
OBO will be for special cases only.
Location URI
IETF-63
19/09/2018

8. Discussion