Signalling techniques and device for high speed data transmission over voiceband channels
First Claim
1. A method for establishing a connection by a call modem to an answer modem in a communication network, the call modem having a standard first modulation mode, a modified first modulation mode, and a standard second modulation mode, the call modem having a configured modulation mode equal to one of the standard first modulation mode and the standard second modulation mode, the method comprising the steps of:
- initiating a call;
determining whether a progression tone generated by the communication network is present;
formatting a first message for transmission to the answer modem, wherein the step of formatting comprises;
setting a requested modulation mode indicator in the first message to indicate one of the standard first modulation mode and the standard second modulation mode;
determining whether a progression tone detected indicator should be included in the first message; and
including the progression tone detected indicator in the first message if the determination is made to include the progression tone detected indicator; and
transmitting the first message to the answer modem.
4 Assignments
0 Petitions
Accused Products
Abstract
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 of aguard tone and a signal S1, wherein an energy of a predetermined guard tone is greater than an energy of a predetermined range of frequencies of the Signal S1; and continuing transmitting and receiving in accordance with the modified V.34 operation.
78 Citations
28 Claims
-
1. A method for establishing a connection by a call modem to an answer modem in a communication network, the call modem having a standard first modulation mode, a modified first modulation mode, and a standard second modulation mode, the call modem having a configured modulation mode equal to one of the standard first modulation mode and the standard second modulation mode, the method comprising the steps of:
-
initiating a call; determining whether a progression tone generated by the communication network is present; formatting a first message for transmission to the answer modem, wherein the step of formatting comprises; setting a requested modulation mode indicator in the first message to indicate one of the standard first modulation mode and the standard second modulation mode; determining whether a progression tone detected indicator should be included in the first message; and including the progression tone detected indicator in the first message if the determination is made to include the progression tone detected indicator; and transmitting the first message to the answer modem. - View Dependent Claims (2, 3, 4, 5, 6, 7)
-
-
8. A method for establishing a connection by an answer modem to a call modem in a communication network, the answer modem having a standard first modulation mode, a modified first modulation mode, and a standard second modulation mode, the answer modem having a configured modulation mode equal to one of the standard first modulation mode and the standard second modulation mode, the method comprising the steps of:
-
answering a call; determining whether a progression tone generated by the communication network is present; receiving from the call modem a first message containing a requested modulation mode indicator for indicating one of the standard first modulation mode and the standard second modulation mode; determining whether a progression tone detected indicator is present in the first message; and selecting a modulation mode according to at least one of; the configured modulation mode; the requested modulation mode indicator; the determination whether the progression tone is present; and the determination whether the progression tone detected indicator is present. - View Dependent Claims (9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20)
-
-
21. A device for establishing a high speed data connection over voiceband channels in a communication network, the device supporting a standard first modulation mode and a standard second modulation mode, each modulation mode having a plurality of phases, each phase having at least one message transmitted by the device, each phase further having at least one message received by the device, the device comprising:
a first phase modifier for modifying a first phase of the standard first modulation mode, the first phase modifier comprising; an information exchange modifier for modifying at least one message transmitted by the device during said first phase; and first modem circuitry, operably coupled to the information exchange modifier, for transmitting and receiving messages. - View Dependent Claims (22, 23, 24, 25, 26)
-
27. In a device which establishes a connection over a communication network using a modulation mode, the modulation mode including logic for transmitting a ranging tone having a first frequency and a first transmit power level and a guard tone having a second frequency and a second transmit power level, the first frequency being equal to a predetermined signaling frequency, the first transmit power level being greater than the second transmit power level, the communication network responsive to the ranging tone and the guard tone for disconnecting the connection, a method for preventing disconnection by the communication network comprising the steps of:
-
modifying the modulation mode to transmit the ranging tone at a third transmit power level; and modifying the modulation mode to transmit the guard tone at a fourth transmit power level;
wherein;the third transmit power level is less than the fourth transmit power level. - View Dependent Claims (28)
-
Specification