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:
Mar. 22, 2011
Filed:
Aug. 12, 2004
Zhigang Rong, Irving, TX (US);
Lin MA, Irving, TX (US);
Steven Craig Greer, Rowlett, TX (US);
Zhigang Liu, Irving, TX (US);
Zhouyue Pi, Irving, TX (US);
Zhigang Rong, Irving, TX (US);
Lin Ma, Irving, TX (US);
Steven Craig Greer, Rowlett, TX (US);
Zhigang Liu, Irving, TX (US);
Zhouyue Pi, Irving, TX (US);
Nokia Corporation, Espoo, FI;
Abstract
The present invention concerns methods for efficiently supporting Voice over Internet Protocol (VoIP) on the Forward Packet Data Channel (F-PDCH) in CDMA 2000 1xEV-DV systems. Active speech in VoIP is encoded using, for example enhanced variable rate codec (EVRC), which produces 171, 80 and 16 bits per 20 ms of speech for Rate 1, Rate ½ and Rate ⅛, respectively. However, about 60% of the time a user is inactive during a speech session, so an inordinate amount of system bandwidth is comprised of rate ⅛ VoIP packets. In one embodiment of the present invention the apparatus of the present invention identifies the Rate ⅛ voice frame packets and discards them. In another embodiment of the present invention, the apparatus of the present invention identifies the Rate ⅛ voice frame packets and selects some of them for further transmission. In both embodiments the efficiency of channel utilization is increased since the amount of channel band width used to communicate relatively little information, e.g., gaps of silence, is decreased.