Call box
First Claim
1. Apparatus for use in an operator-controlled communication system in which one message channel is connected to and directed by each operator for use in conversing with selected field units one at a time, said apparatus noteworthy for enabling an operator to place a first field unit on HOLD in order to answer a call from a second field unit, and enabling the operator to resume her conversation with the first field unit after having conversed with the second field unit for an arbitrary length of time, said apparatus comprising in combination:
- a base station staffed by N operators and including a central processing unit;
a number M of field units distributed within a service area, where M is greater than N;
first means located in part at the field units and in part at the base station and constituting N message channels, each channel connected to one of the N operators, for selective use in carrying conversations between said base station and said field units;
second means located in part at the field units and in part at the base station and constituting a command channel for use by said base station in transmitting commands to said field units;
said central processing unit responsive to an operator-initiated HOLD command following a conversation on message channel I between operator I and field unit J to produce and to send via the command channel a command requiring field unit J to cease transmitting on message channel I and to await a further command on the command channel, thereby permitting the operator I to employ message channel I to hold a conversation with field unit K without interruption by field unit J;
said central processing unit responsive to an operator-initiated ANSWER CALL WAITING command following the conversation with field unit K to produce and to send via the command channel a command requiring field unit J to resume receiving and transmitting on message channel I.
2 Assignments
0 Petitions
Accused Products
Abstract
A communication system having a base station and a number of field units employs a virtual hold technique and a self-testing technique. In the virtual hold technique, when a field unit is put on hold, the communication channel previously used by the field unit is released for use elsewhere in the system, thereby increasing the efficiency of the system. In the self-test technique, a test signal is transmitted to the field unit where it is applied to the earpiece of a handset so as to generate sound waves which are picked up by the microphone in the mouthpiece of the handset and transmitted back to the base station for comparison with the original test signal. In this manner, the entire communication loop is tested without the need for human intervention, and in particular without the need for a person to be present at the field unit. The self-test technique improves the reliability of the system.
24 Citations
7 Claims
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1. Apparatus for use in an operator-controlled communication system in which one message channel is connected to and directed by each operator for use in conversing with selected field units one at a time, said apparatus noteworthy for enabling an operator to place a first field unit on HOLD in order to answer a call from a second field unit, and enabling the operator to resume her conversation with the first field unit after having conversed with the second field unit for an arbitrary length of time, said apparatus comprising in combination:
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a base station staffed by N operators and including a central processing unit; a number M of field units distributed within a service area, where M is greater than N; first means located in part at the field units and in part at the base station and constituting N message channels, each channel connected to one of the N operators, for selective use in carrying conversations between said base station and said field units; second means located in part at the field units and in part at the base station and constituting a command channel for use by said base station in transmitting commands to said field units; said central processing unit responsive to an operator-initiated HOLD command following a conversation on message channel I between operator I and field unit J to produce and to send via the command channel a command requiring field unit J to cease transmitting on message channel I and to await a further command on the command channel, thereby permitting the operator I to employ message channel I to hold a conversation with field unit K without interruption by field unit J; said central processing unit responsive to an operator-initiated ANSWER CALL WAITING command following the conversation with field unit K to produce and to send via the command channel a command requiring field unit J to resume receiving and transmitting on message channel I. - View Dependent Claims (2, 3, 4, 5)
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6. A method for use in a communication system in which one message channel is assigned to and directed by each operator for use in conversing with selected field units one at a time, said method noteworthy for enabling an operator to place a first field unit on HOLD in order to answer a call from a second field unit, and enabling the operator to resume her conversation with the first field unit after having conversed with the second field unit for an arbitrary length of time, said method comprising the steps of:
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providing a common command channel by which operator-initiated commands are transmitted for reception by all of the field units; sending a HOLD command to the first field unit via the common command channel requiring the first field unit to cease transmitting on and receiving the message channel and to receive instead the common command channel, whereby the message channel is freed from the first field unit; answering the call from the second field unit and conversing with the second field unit via the message channel; sending an ANSWER CALL WAITING command, after the conclusion of the conversation with the second field unit, to the first field unit via the common command channel, ordering the first field unit to resume receiving and transmitting on the message channel, whereby the operator can resume her conversation with the first field unit. - View Dependent Claims (7)
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Specification