Patents Examined by Philip J. Sabutka
  • Patent number: 6243588
    Abstract: Standard mobile cellular telephones use shortened burst signal transmissions to synchronize the transmission of a call over a cellular telephone network. These shortened bursts as well as other traffic channel bursts can be used to locate the position of the cell phone. In operation, a primary base station sends a traffic channel designation message to a selected mobile phone which then initiates selected traffic channel burst transmissions, such as shortened bursts, over an interval of five seconds or less. The primary station and at least two other neighboring base stations receive these burst transmissions and determine their respective distances from the cell phone based upon the time of arrival of the bursts or some other suitable distance related measurement. A command center determines the location of the cell phone by triangulating the distance measurements of the base stations.
    Type: Grant
    Filed: March 10, 1998
    Date of Patent: June 5, 2001
    Assignee: Ericsson Inc.
    Inventors: Havish Koorapaty, Patrick Nils Lundqvist, Alex Krister Raith