The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Oct. 13, 1998
Filed:
May. 24, 1996
Charles J Malek, Crystal Lake, IL (US);
David L Weigand, Sunnyvale, CA (US);
Dennis M Rose, Sunnyvale, CA (US);
Gerard G Socci, Palo Alto, CA (US);
National Semiconductor Corporation, Santa Clara, CA (US);
Abstract
A technique is disclosed for allowing a seamless handover between base stations in a TDMA controller as a telephone handset is transported from one base station's area to another. The disclosed circuitry enables the TDMA controller to assess the quality of the handover before switching to the new base station. When it is determined that a handover operation is to commence, transmissions are made in the original slot time and a handover slot time within the same frame. Also during the same frame, data is received at two separate slot times. Only when it is determined that the data received in the handover slot time contains no transmission errors is the handover completed by then only transmitting on the handover slot transmit time and receiving on the handover slot receive time. In the preferred embodiment, it is determined whether the received data contains no transmission errors by detecting the CRC codes, the signal strength, and the existence of any invalid words.