Efficient usage of emergency services keys

Abstract

An emergency services key (e.g., ESQK or ESRK) is guaranteed to be available from a limited size ESQK pool, such that an available ESQK is always selected and associated with an ongoing emergency call with no measurable impact to existing calls, even if all ESQK pool members are marked as unavailable. A plurality of ESQKs are grouped into a pool of emergency service keys “ESQK Pool ID”, each including anywhere from 1 to N number of ESQKs. Each ESQK preferably has a “Timestamp”, and information relating to the specific emergency E911 call (“Call Data ID”). The ESQK having a Call Data ID=“NULL”, and having the oldest Timestamp, is chosen for selection. If no such ESQK has both Call Data ID=NULL and the oldest Timestamp is found, then the ESQK with merely the oldest Timestamp is selected.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

Features and advantages of the present invention will become apparent to those skilled in the art from the following description with reference to the drawings:

FIG. 1 shows an exemplary ESQK data store, in accordance with the principles of the present invention.

FIG. 2 shows an exemplary ESQK data store contents, in accordance with the principles of the present invention.

FIG. 3 illustrates exemplary selection of an emergency services key (e.g., an emergency services query key (ESQK)) from a pool of ESQK keys, in accordance with the principles of the present invention.

FIG. 4 shows a conventional landline public safety access point (PSAP) to automatic location identifier (ALI) connection.

FIG. 5 shows a context diagram for a conventional non-landline positioning center (e.g., an Internet based voice over Internet Protocol (VOIP) positioning center).

DETAILED DESCRIPTION OF ILLUSTRATIVE EMBODIMENTS

The present invention provides for the management of a limited size emergency services key pool (e.g., an ESQK pool) in such a way as to ensure that an ESQK can always be handed out to an incoming emergency call, even if all ESQK pool members are marked as unavailable. The invention applies equally to efficient use of emergency services routing keys (ESRKS) used in the wireless industry where the gateway mobile location centre (GMLC) takes the functional role of the voice over Internet Protocol (VOIP) positioning center (VPC). Ultimately the invention applies to any limited size pool of unique numbers that need to be dynamically allocated to a resource for a limited time in such a way to always guarantee the availability of a pool element.

Selecting an ESQK from a Pool:

FIG. 1 shows an exemplary ESQK data store 200, in accordance with the principles of the present invention.

In particular, as shown in FIG. 1, a plurality of ESQKs are grouped into a pool of emergency service keys, identified herein with an “ESQK Pool ID” 201.

The ESQK pool ID includes ESQK(s) 202. The ESQKs 202 element of the ESQK data store 200 is capable of containing anywhere from 1 to N number of ESQKs, N being any number greater than 1, as depicted row 202 of FIG. 1.

The size of N is limited by network factors, such as the size of a database, but mostly based on the number of ESQKs assigned for use by the given network element.

Each ESQK 202 preferably has a “Timestamp” associated therewith, as shown in row 203. The timestamp preferably relates to a representation of the current time of day of assignment to a specific emergency E911 call.

Each ESQK 202 also includes information relating to the specific emergency E911 call, referred to herein as “Call Data ID”, as depicted in row 204 of FIG. 1. The Call Data ID information identifies the specific emergency E911 call.

FIG. 2 shows exemplary contents of an ESQK data store 200 in more detail, in accordance with the principles of the present invention.

In particular, as shown in FIG. 2, an exemplary ESQK Data Store includes two (2) ESQK pools: ESQK pool #1 (rows 301 and 302) and ESQK pool #2 (rows 303 and 304). Each of the exemplary ESQK pools #1 and #2 contain two ESQKs, as shown in column 202.

FIG. 3 illustrates an exemplary selection of an emergency services key (e.g., an emergency services query key (ESQK)) from a pool of ESQK keys, in accordance with the principles of the present invention.

In particular, as shown in FIG. 3, an ESQK is picked as follows for a given ESQK pool.

In step 100 of FIG. 3, the ESQK in the ESQK pool having a Call Data ID equal to “NULL” (NULL is used as a synonym for “not set” in this context), and having the oldest Timestamp, is chosen for selection.

In decision step 102, it no such ESQK having both Call Data ID=NULL and the oldest Timestamp is found in the given ESQK pool 200, then the method moves to step 104 where the ESQK with merely the oldest Timestamp is selected.

The inherent logic is that in the latter scenario ESQKs that are no longer associated with active emergency calls are still incorrectly marked to be in use for whatever system related issues. This logic is no longer true under extreme conditions, such as an ESQK pool sized too small, or extremely high call volume, typically generated in a lab stress test environment. For most practical purposes the likelihood of this happening is extremely low. In this way, the inventive method always guarantees the selection of an ESQK as long as the number of ESQKs in a given pool is >=1.

In step 106, the Timestamp and Call Data ID are preferably updated.

Returning an ESQK to a Pool:

When an emergency call is terminated the ESQK that has been associated with this call up to that point is released. To achieve this, the ESQK record is retrieved from the ESQK data store 200, and the Call Data ID 204 parameter for that particular ESQK record is set to NULL.

However, in the call termination process, the Timestamp 203 parameter for that ESQK record is left unchanged. In this way, the ESQK record that was used retains the Timestamp of the last time it was selected.

As an example use of the inventive method, a request for an ESQK from ESQK pool #1 shown earlier in FIG. 2 would follow the method described and shown with respect to FIG. 3. In the given example, ESQK “11111111111” (row 301) would be chosen since it has a Call Data ID=NULL, and the oldest Timestamp.

A request for an ESQK from ESQK pool #2 would also follow the method described and shown with respect to FIG. 3. All ESQKs in ESQK pool #2 as depicted still have a value assigned as a Call Data ID. For instance, the ESQK in row 303 has a Call Data ID=1234, and the ESQK in row 304 has a Call Data ID=5678. Because the values for these Call Data ID is NOT NULL, they are both considered to be marked as “in-use” as referred to herein.

In this particular example, ESQK “33333333333” (row 303) would be chosen since no ESQK in the ESQK pool (i.e., ESQK pool #2) has a Call Data ID=NULL, and that ESQK (i.e., ESQK “3333333333” (row 303) is the ESQK in that ESQK pool having the oldest Timestamp. In this example, the oldest Timestamp is “Two days ago @8:00 AM”.

While the Timestamp is represented as “Two days ago @8:00 AM”, it is entirely within the principles of the present invention that other representations for a Timestamp are possible. For instance, the Timestamp may be represented in YYYY/MM/DD/HH/MM/SS format, or equivalent, as an example.

Accordingly, the invention guarantees that for a limited size ESQK pool, an ESQK can always be selected and associated with an ongoing emergency call with no measurable impact to existing calls.

While the disclosed examples relate to the selection of an emergency services query key (ESQK), the present invention is equally applicable to the selection of an emergency services routing key (ESRK).

While the invention has been described with reference to the exemplary embodiments thereof, those skilled in the art will be able to make various modifications to the described embodiments of the invention without departing from the true spirit and scope of the invention.

Claims

1. A method of selecting an emergency services key from a limited size pool, comprising: first attempt selecting an emergency services key from a limited size pool containing a plurality of emergency services keys, having an indication of not being currently associated with an emergency call, and having an oldest timestamp associated therewith from among those in said pool; andsecond attempt selecting said emergency services key from said limited size pool having merely an oldest timestamp associated therewith from among those in said pool, in the event that no emergency services key in said pool meets said first attempt selecting criteria;whereby selection of said emergency services key is ensured from said limited size pool is assured to be available when selected.

2. The method of selecting an emergency services key from a limited size pool according to claim 1, wherein: said emergency services key is an emergency services query key (ESQK).

3. The method of selecting an emergency services key from a limited size pool according to claim 1, wherein: said emergency services key is an emergency services routing key (ESRK).

4. The method of selecting an emergency services key from a limited size pool according to claim 1, whereby: said second attempt selecting produces no measurable impact to existing emergency calls, even if all of said plurality of emergency services keys are marked as being currently associated with an emergency call.

5. The method of selecting an emergency services key from a limited size pool according to claim 1, wherein: said indication contains a NULL if not currently associated with an emergency call.

6. Apparatus for selecting an emergency services key from a limited size pool, comprising: means for first attempting selection of an emergency services key from a limited size pool containing a plurality of emergency services keys, having an indication of not being currently associated with an emergency call, and having an oldest timestamp associated therewith from among those in said pool; andmeans for second attempting selection of said emergency services key from said limited size pool having merely an oldest timestamp associated therewith from among those in said pool, in the event that no emergency services key is selected by said means for first attempting selection criteria;whereby selection of said emergency services key is ensured from said limited size pool is assured to be available when selected.

7. The apparatus for selecting an emergency services key from a limited size pool according to claim 6, wherein: said emergency services key is an emergency services query key (ESQK).

8. The apparatus for selecting an emergency services key from a limited size pool according to claim 6, wherein: said emergency services key is an emergency services routing key (ESRK).

9. The apparatus for selecting an emergency services key from a limited size pool according to claim 6, whereby: said means for second attempting selection produces no measurable impact to existing emergency calls, even if all of said plurality of emergency services keys are marked as being currently associated with an emergency call.

10. The apparatus for selecting an emergency services key from a limited size pool according to claim 6, wherein: said indication contains a NULL if not currently associated with an emergency call.