When a Location Information Server receives a request for location
information (using the locationRequest message), described in the
base HTTP Enabled Location Delivery (HELD) specification, it uses the
source IP address of arriving message as a pointer to the location
determination process. This is sufficient in environments where the
location of a Device can be determined based on its IP address.
Two additional use cases are addresses by this document. In the
first, location configuration requires additional or alternative
identifiers from the source IP address provided in the request. In
the second, an entity other than the Device requests the location of
This document extends the HELD protocol to allow the location request
message to carry Device identifiers. Privacy and security
considerations describe the conditions where requests containing
identifiers are permitted.