Switched line modem interface system
First Claim
1. In a circuit switched network data transmission link between terminal means at a terminal location and a host computer at a remote location wherein the host computer is accessed through the circuit switched network at a host end, the terminal means is connected to the circuit switched network by a single line which includes at least one service feature and an application program running in the terminal means, the improvement comprising a switched line modem interface system, the system comprising means for determining when a user desires to utilize the service feature on the single line during a data session and means at the terminal location for preventing loss of the data session when the user utilizes the single line for the service feature, the means for preventing loss of the data session being free of interaction with the application program, the means for preventing loss including means at the terminal location for generating a signal and means for transmitting the signal to the host end, and means at the host end for maintaining the data session in response to said signal, the system further including means responsive to the termination of the service feature on the single line for reestablishing the data session.
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Accused Products
Abstract
A system is provided in a circuit switched network data transmission link between a user terminal and a host computer in instances where the terminal is connected to the network by a single telephone line and the terminal user has subscribed to a telephone company service feature such as call waiting. The system includes an interface at the terminal location between the telephone line and the terminal equipment. During a data session the interface detects a call waiting signal and generates a user signal. If the user desires to take the incoming call and suspend a data session, the interface responds to the telephone receiver being lifted off-hook and communicates through the circuit switched network with an interface at the host end of the communication. The host interface is programmed to maintain the data session at the host computer during a suspension of the communication by generating a signal simulating a terminal location signal. The terminal interface locally generates a signal indicating that the host is not ready and toggles the telephone company central office to switch the user'"'"'s line to the incoming call. To resume the data session, the user places the telephone instrument on hook and the terminal interface toggles the central office to access the host interface for the purpose of resuming the data session.
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Citations
19 Claims
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1. In a circuit switched network data transmission link between terminal means at a terminal location and a host computer at a remote location wherein the host computer is accessed through the circuit switched network at a host end, the terminal means is connected to the circuit switched network by a single line which includes at least one service feature and an application program running in the terminal means, the improvement comprising a switched line modem interface system, the system comprising means for determining when a user desires to utilize the service feature on the single line during a data session and means at the terminal location for preventing loss of the data session when the user utilizes the single line for the service feature, the means for preventing loss of the data session being free of interaction with the application program, the means for preventing loss including means at the terminal location for generating a signal and means for transmitting the signal to the host end, and means at the host end for maintaining the data session in response to said signal, the system further including means responsive to the termination of the service feature on the single line for reestablishing the data session.
- 2. In a circuit switched network data transmission link between terminal means at a terminal location and a host computer at a remote location wherein the host computer is accessed through the circuit switched network at a host end and, the terminal means is connected to the circuit switched network by a single line which includes at least one service feature, the improvement comprising a transparent switched line modem interface system, the system comprising means for determining when a user desires to utilize the service feature on the single line during a data session and means for preventing loss of the data session when the user utilizes the single line for the service feature, the means for preventing loss of the data session including means at the terminal location for generating a signal indicating that the host computer is not ready in simulation of a signal generated at the host location and transmitted to the terminal location through the circuit switched network, the system further including means responsive to the termination of the service feature on the single line for reestablishing the data session.
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10. A method of suspending a data transmission through a circuit switched network between a terminal means at a terminal location and host computer means connected to the network at a host end of the network which is transparent to both the terminal means and the host computer means and wherein the terminal means is connected to the circuit switched network by a single line having at least one service feature, the method comprising the steps of:
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(a) determining whether a user at the terminal location desires to utilize a service feature, (b) generating a signal at the terminal location in simulation of a host end transmitted signal, (c) transmitting the simulated host end signal to the terminal means, (d) generating a signal remote from the terminal location in simulation of a terminal location generated signal, (e) transmitting the simulated terminal location generated signal to the host computer means and, (f) suspending the communications link between the terminal location and the host end through the circuit switched network while maintaining the simulated signals. - View Dependent Claims (11, 12, 13, 14)
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- 15. In a circuit switched network data transmission link between terminal means at a terminal location and a host computer at a remote location wherein the host computer is accessed through the circuit switched network at a host end, the terminal means is connected to the circuit switched network by a single line which includes at least one service feature, the improvement comprising a transparent switched line modem interface system, the system comprising means for determining when a user desires to utilize the service feature on the single line during a data session, means for preventing loss of the data session when the user utilizes the single line for the service feature, the means for preventing loss of a data session including means remote from the terminal location for generating a signal indicating that the terminal means requests suspension of a data session not ready in simulation of a signal generated at the terminal location and transmitted to the host computer end through the circuit switched network and means for transmitting such signal to the host computer end modem, the system further including means responsive to the termination of the service feature on the single line for reestablishing the data session.
Specification