Duplicate device detection system

• US 6,069,877 A
• Filed: 10/18/1996
• Issued: 05/30/2000
• Est. Priority Date: 10/18/1996
• Status: Expired due to Term

• Current Assignee: Symbol Technologies, LLC (Zebra Technologies Corporation)
• Original Assignee: Telxon Corporation (Zebra Technologies Corporation)
• Inventors: Yang, Ming-Chung
• Primary Examiner(s): VU, HUY DUY
• Application Number:
  US08/731,399
• Time in Patent Office: 1,320 Days
• Field of Search: 370/252, 370/241, 370/242, 370/310, 370/328, 370/329, 370/338, 370/522, 455/67.1, 455/517, 455/433, 455/435, 455/434
• US Class Current: 370/252
• CPC Class Codes: H04W 60/005 Multiple registrations, e.g. multihoming
• CPC Class Codes: H04W 76/10 Connection setup
• CPC Class Codes: H04W 8/26 Network addressing or numbering for mobility support

Abstract

A network communication system with duplicate device detection in which a mobile communication unit, attempting to register to a communication network with a duplicate identification code as that of another mobile communication unit already registered, is detected and refused registration to the network. As a result, the mobile communication unit already registered to the network is not deregistered. Furthermore, the network communication system is not locked-up due to the existence within the system of two mobile communication units with the same identification code, thereby preserving data integrity within system and reducing potential downtime of the system due to lock-up.

Claims

1. A method of controlling registration of a mobile communication unit of a plurality of mobile communication units to a communication network including the steps of:

building a session packet for a first mobile communication unit with a flag set to "ON" if the session request is an initial request or setting the flag to "OFF" otherwise;

receiving a session request from the first mobile communication unit;

determining if the session request of the first mobile communication unit is an initial session request;

determining a mobile communication unit identification code of the first mobile communication unit;

registering the first mobile communication unit to the network;

receiving a session request from a second mobile communication unit;

determining a mobile communication unit identification code of the second mobile communication unit;

determining if the mobile communication unit identification code of the second mobile communication unit is an apparent duplicate of the mobile communication unit identification code of the first mobile communication unit; and

refusing registration to the second mobile communication unit if the mobile communication unit identification code of the second mobile communication unit is an apparent duplicate of the mobile communication unit identification code of the first mobile communication unit.

2. The method of claim 1, further including the step of determining if the session request of the first mobile communication unit is not an initial request via its flag setting, and permitting re-registration of the first mobile communication unit to the communication network if the session request is not an initial session request.

3. The method of claim 1, wherein the first mobile communication unit is the same as the second mobile communication unit.