发明名称 |
SIGNALLING TECHNIQUES AND DEVICE FOR HIGH SPEED DATA TRANSMISSION OVER VOICEBAND CHANNELS |
摘要 |
The present method (200, 300, 400) and device (500, 600, 700) modify phase two of the format set forth in the V.34 Recommendation of the International Telecommunication Union-Telecommunication Standardization Sector to prevent premature disconnection of calls between a call modem and an answer modem. The method and device efficiently ensure connection of the call for high speed data transmission over voiceband channels, by modification of one of: a phase preliminary to phase one and phase two. One implementation, in the answer modem, includes transmitting a signal having first information, followed by a Signal S comprising a guard tone and a signal SI, wherein an energy of a predetermined guard tone is greater than an energy of a predetermined range of frequencies of the Signal SI; and continuing transmitting and receiving in accordance with the modified V.34 operation.
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申请公布号 |
WO9619047(A1) |
申请公布日期 |
1996.06.20 |
申请号 |
WO1995US13679 |
申请日期 |
1995.10.25 |
申请人 |
MOTOROLA INC. |
发明人 |
BROWN, WILLIAM, LESLIE;MORAN, JOHN, L., III;SRIDHAR, MANICKAM, R. |
分类号 |
H04M11/06;(IPC1-7):H04B1/38;H04J3/12;H04M11/00 |
主分类号 |
H04M11/06 |
代理机构 |
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代理人 |
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主权项 |
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地址 |
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