Method and system utilizing a pointer strategy to locate nomadic users in a communication services system

• US 5,606,596 A
• Filed: 05/05/1995
• Issued: 02/25/1997
• Est. Priority Date: 07/26/1993
• Status: Expired due to Term

• Current Assignee: Intellectual Ventures II LLC (Intellectual Ventures LLC)
• Original Assignee: Bell Communications Research, Inc. (Telefonaktiebolaget LM Ericsson)
• Inventors: Lo, Charles N., Mohan, Seshadri, Jain, Ravi K.
• Primary Examiner(s): Kim, Kenneth S.
• Application Number:
  US08/435,571
• Time in Patent Office: 662 Days
• Field of Search: 379/57, 379/58, 379/59, 379/60, 455/33.1, 455/54.1, 455/56.1
• US Class Current: 455/433
• CPC Class Codes: H04W 60/00 Affiliation to network, e.g. registration; Terminating affiliation with the network, e.g. de-registration
• CPC Class Codes: H04W 76/20 Manipulation of established connections
• CPC Class Codes: H04W 8/06 Registration at serving network Location Register, VLR or user mobility server

Abstract

Method and system for locating nomadic users in a personal communication services (PCS) system by utilizing two strategies for locating such users and a per-user criterion for determining which, if any, of the two strategies should be used. The method and system augment basic two-level strategies for locating users specified in IS-41 and GSM standards of PCS systems. One strategy utilizes forwarding pointers and the other strategy utilizes per-user location caching. One per-user criterion is a call-to-mobility ratio (CMR) which is the ratio of the average rate at which a user receives calls to the average rate at which the user moves. A variation of this criterion is the local CMR (LCMR) which is the ratio of the average rate at which a user receives calls from a given registration area, to the average rate at which the user moves. The method and system reduce the average time and overhead required to locate and deliver information to such nomadic users.

Claims

1. A method for locating nomadic users in a personal Commmunication Services (PCS) system having a plurality of registration area wherein each user is identified with a home database and each registration area is identified with a visiting database, the method comprising the steps of:

(a) collecting data based on the user'"'"'s location in a first registration area obtained during a first PCS call to the user from a second registration area;

(b) storing the data in the home database;

(c) detecting movement of the user from the first registration area to a third registration area;

(d) generating and storing a pointer in a visiting database identified with the first registration area, the pointer identifying the location of the user in the third registration area;

(e) detecting a second PCS call;

(f) retrieving the data from the home database based on the second PCS call to identify the first registration area;

(g) utilizing the data to access the pointer in the visiting database of the first registration area;

(h) utilizing the pointer to determine the user'"'"'s correct current location in the third registration area; and

(i) generating routing data to route the second PCS call to the third registration area.

2. A system for locating nomadic users in a Personal Communication Services (PCS) system having a plurality of registration areas wherein each user is identified with a home database and each registration area is identified with a visiting database, the system comprising:

means for collecting data based on the user'"'"'s location in a first registration area obtained during a first PCS call to the user from a second registration area;

means for storing the data in the home database;

means for detecting movement of the user from the first registration area to a third registration area;

means for generating and storing a pointer in a visiting database identified with the first registration area, the pointer identifying the location of the user in the third registration area;

means for detecting a second PCS call;

means for retrieving the data from the home database based on the second PCS call to identify the first registration area;

means for utilizing the data to access the pointer in the visiting database of the first registration area;

means for utilizing the pointer to determine the user'"'"'s correct current location in the third registration area; and

means for generating routing data to route the second PCS call to the third registration area.

3. The system as claimed in claim 2 further comprising

means for calculating a per-user criterion which is a ratio of an average rate at which a user receives PCS calls to an average rate at which the user moves between registration areas and

means for storing the per-user criterion in at least one of the visiting databases identified with the first and third registration areas, said means for utilizing the data to access the pointer in the visiting database of the first registration area being responsive to the per-user criterion in said storing means.

4. A method for locating in a communication service system nomadic users who move frequently but receive relatively few calls by utilizing a forwarding pointer strategy, said system having a plurality of registration areas wherein each user is identified with a home database and each registration area is identified with a visiting database, the method comprising the steps of

collecting data based on the user'"'"'s location in a first registration area obtained during a first call to the user from a second registration area,

storing the data in the home database,

detecting movement of the user from the first registration area to a third registration area,

generating and storing a pointer in a visiting database identified with the first registration area, the pointer identifying the location of the user in the third registration area,

detecting a second call,

retrieving the data from the home database based on the second call to identify the first registration area,

utilizing the pointer stored in the visiting database identified with the first registration area to determine the user'"'"'s correct current location in the third registration area, and

generating routing data to route the second call to the third registration area.

5. A method for locating in a communication service system nomadic users who move frequently but receive relatively few calls by utilizing a forwarding pointer strategy, said system having a plurality of registration areas wherein each user is identified with a home database and each registration area is identified with a visiting database, the method comprising the steps of

collecting data based upon the user'"'"'s location in a first registration area obtained during a first call to the user from a second registration area;

storing the data in the home database;

detecting movement of the user to a third registration area;

generating and storing a pointer on a visiting database identified in the first registration area, the pointer identifying the location of the user in the third registration area;

calculating a call-to-mobility ratio for the user, said ratio being the ratio of an average rate at which the user receives calls to an average rate at which the user moves between registration areas,

detecting a second call and retrieving the data from the home database based on the second call to identify the first registration area; and

dependent on the value of said call-to-mobility ratio for the user, utilizing the pointer to determine the user'"'"'s correct current location in the third registration area and routing the second call to the third registration area.

6. A method for locating in a communications service system nomadic users who move frequently but receive relatively few calls by utilizing a forwarding pointer strategy, said system having a plurality of registration areas wherein each user is identified with a home database and each registration area is identified with a visiting database, the method comprising the steps of

collecting data based on the user'"'"'s location in a first registration area obtained during a first call to the user from a second registration area,

storing the data in a home database,

detecting movements of the user from the first registration area to subsequent registration areas,

generating and storing a pointer in the visiting database identified with the first registration area and with each subsequent registration area through which the user has passed, the pointers identifying each subsequent registration area in sequence,

detecting a second call,

retrieving the data from the home database based on the second call to identify the first registration area,

utilizing the pointer stored in sequence in the first and subsequent registration areas to determine the user'"'"'s current location in a registration area, and

generating routing data to route the second call to that registration area in which the user is currently located.