[54] SYSTEM AND METHOD FOR CONNECT MESSAGE SYNCHRONIZATION OF MODEMS IN A CELLULAR DATA GATEWAY
[75] Inventors: Robert Earl Scott, Indian Rocks
Beach; E. Robert Lastinger, Jr.. Lithia. both of Fla.
[73] Assignee: Paradyne Corporation
[21] Appl. No.: 780,238
[22] Filed: Jan. 8, 1997
Related U.S. Application Data
[60] Provisional application No. 60/026,970 Sep. 20, 1996 and 60/022,474 Jun. 21, 1996.
[51] Int CL6 H01Q 7/24
[52] U.S. CI 455/557; 458/560; 379/93.32;
375/222
[58] Field of Search 455/557, 559,
455/560, 414. 422, 426. 445, 507, 517, 403, 401; 379/93.32. 93.31, 93.33, 93.34, 93.28; 375/222,231. 377
[56] References Cited
U.S. PATENT DOCUMENTS
4,837,800 6/1989 Freeburg et al 455/557
5,249,218 9/1993 Sainton 379/93
5,570,389 10/1996 Rossi 455/557
Primary Examiner—Nguyen Vo
Assistant Examiner—-Lester G. Kincaid
Attorney, Agent, or Firm—-Thomas. Kayden, Horstemeyer & Risley L.L.P.
[57] ABSTRACT
A cellular data gateway situated at a mobile telecommunications switching office (MSC) is provided for interconnecting an originating mobile modem of an analog cellular system to an answer modem of a public switched telephone network (PSTN) when one of the either the cellular side or the PSTN side of the connection is capable of a fast connection sequence. The cellular data gateway comprises a quick connect cellular modem connected to the MSC and configured for interfacing with the originating mobile modem. The cellular data gateway further includes a PSTN modem connected to the MSC and configured for interfacing with the answer modem of the PSTN. The cellular modem and the PSTN modem are interconnecting in the cellular data gateway as a back-to-back modem pair. As an important part of the invention, the cellular modem includes a mechanism for delaying the initiation of a fast connect sequence with the originating mobile modem until the PSTN modem has established a connection with the answer PSTN modem. The connection of the PSTN modems is preferably signaled to the cellular modem by a carrier detect (CD) signal, that is, at the establishment of the physical layer connection. This essentially ensures that the cellular side of the connection (between the originating mobile modem) and the cellular modem and the PSTN side of the connection (between the PSTN modem and the answer PSTN modem) have substantially synchronized connect messages. Alternatively, the connection of the PSTN modems can be signaled to the cellular modem by a connect signal from the PSTN modem.
12 Claims, 5 Drawing Sheets
