Maintaining triggered session state in secure user plane location (SUPL) enabled system

A non-transitory computer readable medium storing code executable by a computer processor for maintaining session state in a Secure User Plane Location (SUPL) enabled system, the computer readable medium comprising:

• a modifying code segment for modifying at least one parameter of a session message to include state data necessary to maintain session state of a triggered session;
• a transmitting code segment for enabling transmission of a request to a SUPL Enabled Terminal (SET) to initiate the triggered session over a given communication channel, the request comprising the session message having the at least one modified parameter, enabling the state data to be stored at the SET;
• a closing code segment for closing the given communication channel after the session message is received by the SET;
• a clearing code segment for clearing the state data from memory of the SUPL enabled system in response to the closing, wherein the SET maintains the only copy of the state data;
• a receiving code segment for receiving a triggered message from the SET over another communication channel in response to occurrence of a trigger event detected by the SET during the triggered session, the triggered message comprising the stored state data;
• and
• an identifying code segment for re-establishing the triggered session using the state data received in the triggered message;
• wherein the receiving code segment is for receiving a SUPL POS message from the SET, the SUPL POS message including position data indicating a location of the SET and setting an estimated position of the SET using the position data in the SUPL POS message.

A method of maintaining session state in a Secure User Plane Location (SUPL) enabled system during a triggered session, without a SUPL Location Platform (SLP) maintaining state necessary to re-establish the triggered session, the method comprising:

• setting free bits of a SlpSessionID parameter in a session message at the SLP to include state data necessary to maintain the session state of the triggered session;
• transmitting the session message a SUPL Enabled Terminal (SET) from the SLP to the SET to initiate the triggered session over a given communication channel, the SET storing the free bits of the SlpSessionID;
• closing the given communication channel after the SET receives the session message;
• clearing the state data from memory of the SLP in response to the closing, wherein the SET maintains the only copy of the state data;
• receiving a SUPL POS INIT message from the SET over another communication channel upon occurrence of a trigger event to initiate position determination as part of the triggered session, the SUPL POS INIT message comprising the stored state data;
• re-establishing the triggered session using the stored data in the SUPL POS INIT message;
• receiving a SUPL POS message from the SET, the SUPL POS message including position data indicating a location of the SET;
• and
• calculating an estimated position of the SET using the position data in the SUPL POS message.