US5200990A — Method of recovering speech path of pre-engaged c…

Claim 1

Independent Claim 197 words

A method of recovering a speech path of a pre-engaged call upon restarting a keyphone exchange system after the occurrence of a system failure, comprising the steps of: initializing all hardware and all software except for a subscriber's table buffer of said keyphone exchange system when a predetermined restarting signal of said system is generated; initializing a variable number of a port in the communication control software as a given initial value; generating an address of a port number corresponding to said variable number of said port in said subscriber's table buffer; checking whether a talk bit of a line status word in a port identified by said port number is set or not, said line status word indicating status of said port; obtaining a subscriber's port number from a line number buffer and obtaining an opposite subscriber's port number from an opposite party if said talk bit is set, said line number buffer storing said subscriber's port number and said opposite party storing said opposite subscriber's port number; and forming said speech path of said call by connecting said subscriber's port number in said line number with said opposite subscriber's port number in said opposite party.

Claim 2

Independent Claim 197 words

A method of recovering a speech path of a pre-engaged call upon restarting a keyphone exchange system after the occurrence of a system failure, comprising the steps of: initializing all hardware and all software except for a subscriber's table buffer of said keyphone exchange system when a predetermined restarting signal of said system is generated; initializing a variable number of a port in the communication control software as a given initial value; generating an address of a port number corresponding to said variable number of said port in said subscriber's table buffer; checking whether a talk bit of a line status word in a port identified by said port number is set or not, said line status word indicating status of said port; obtaining a subscriber's port number from a line number buffer and obtaining an opposite subscriber's port number from an opposite party if said talk bit is set, said line number buffer storing said subscriber's port number and said opposite party storing said opposite subscriber's port number; and forming said speech path of said call by connecting said subscriber's port number in said line number with said opposite subscriber's port number in said opposite party.

Claim 3

Dependent Claim 85 words

The method of recovering a speech path of a pre-engaged call on restarting a keyphone exchange system after the occurrence of a system failure as claimed in claim 1, further comprising the step of altering said variable number of said port to a given value and checking whether said variable number of said port is a last number or not, and, if not, performing repeatedly said connecting steps of said speech path of said call for a next port, when said talk bit is set.

Claim 4

Dependent Claim 86 words

The method of recovering a speech path of a pre-engaged call after restarting a keyphone exchange system after the occurrence of a system failure as claimed in claim 1, further comprising the step of altering said variable number of said port to a given value and checking whether said variable number of said port is a last number or not, and, if not, performing repeatedly connecting steps of said speech path of said call for a next port, after connecting said speech path of said call.

Claim 5

Dependent Claim 61 words

The method as claimed in claim 1, wherein said subscriber's table buffer is comprised of a plurality of ports and each of said plurality of ports is comprised of said line status word indicating a state of each of said plurality of ports, said line number storing said subscriber's port number, and said opposite party storing said opposite subscriber's port number.

Claim 6

Dependent Claim 28 words

The method as claimed in claim 4, wherein said line status word is comprised of an idle bit, a busy bit, a talking bit, and a hold bit.

Claim 7

Dependent Claim 80 words

The method as claimed in claim 4, wherein said line status word is comprised of: an idle bit for indicating whether said port is in use; a busy bit for indicating whether said port is engaged in a call not with said opposite subscriber's port; a talk bit for indicating the state of communication between said port and an office line or an extension line; and a hold bit for indicating whether said port is in a state of holding.

Claim 8

Dependent Claim 55 words

The method as claimed in claim 1, further comprising the step of determining a restarting grade of the keystone exchange system, a major grade occurring when restarting the system from power-on or power off-on and a minor grade occurring when restarting a system from system failure or in response to use of a reset button.

Claim 9

Dependent Claim 54 words

The method as claimed in claim 2, further comprising the step of determining a restarting grade of the keyphone exchange system, a major grade occurring when restarting the system from power-on or power off-on and a minor grade occurring when restarting a system from system failure on software or use of a reset button.

Claim 10

Independent Claim 106 words

A method of recovering a speech path of a pre-engaged call upon restarting a keyphone exchange after occurrence of a system failure, comprising the steps of: recording information on the progress of each call on the system in a call buffer, including the status of the call, a line number allocated to each port and the port number of the opposite party engaged in the call; checking whether a given port is engaged in a call to an opposite party; and connecting a speech path between said given port and said opposite party if said given port is engaged in a call to said opposite party.

Claim 11

Independent Claim 106 words

A method of recovering a speech path of a pre-engaged call upon restarting a keyphone exchange after occurrence of a system failure, comprising the steps of: recording information on the progress of each call on the system in a call buffer, including the status of the call, a line number allocated to each port and the port number of the opposite party engaged in the call; checking whether a given port is engaged in a call to an opposite party; and connecting a speech path between said given port and said opposite party if said given port is engaged in a call to said opposite party.

Claim 12

Dependent Claim 92 words

A method as claimed in claim 9, the step of recording information on the progress of each call on the system in a table buffer, further comprising the steps of: recording the state of each call in a line status word comprising four bits, each bit representing an idle condition, a busy condition, a talk condition and a hold condition, respectively; recording a specific number allocated in hardware to each port of the system; and recording the port number of the opposing party when said given port is engaged in a call.

Claim 13

Dependent Claim 39 words

A method as claimed in claim 10, wherein the step of checking whether said given port is engaged in a call to an opposite party further comprises the step of checking the talk bit of said line status word.

Claim 14

Dependent Claim 46 words

A method as claimed in claim 9, wherein the step of connecting a speech path between said given port and said opposite party further comprises the steps of: detecting the port number corresponding to said line number; detecting the opposite port number of said opposite party.

Claim 15

Dependent Claim 47 words

A method as claimed in claim 11, wherein the step of connecting a speech path between said given port and said opposite party further comprises the steps of: detecting the port number corresponding to said line number; and detecting the opposite port number of said opposite party.

Claim 16

Dependent Claim 24 words

A method as claimed in claim 9, further comprising the steps of: initializing all hardware; and initializing all software except for said call buffer.

Claim 17

Dependent Claim 24 words

A method as claimed in claim 13, further comprising the steps of: initializing all hardware; and initializing all software except for said call buffer.

Claim 18

Dependent Claim 47 words

A method as claimed in claim 9, further comprising the steps of: incrementing the port number to produce an incremented port number; and determining whether to continue connecting speech paths between ports and opposite parties in dependence upon whether said incremented port number is a last number.

Claim 19

Dependent Claim 47 words

A method as claimed in claim 15, further comprising the steps of: incrementing the port number to produce an incremented port number; and determining whether to continue connecting speech paths between ports and opposite parties in dependence upon whether said incremented port number is a last number.

Claim 20

Dependent Claim 188 words

A keyphone exchange system for recovering a speech path of a per-engaged call upon restarting of said keyphone exchange system after occurrence of a system failure comprising: an extension subscriber matching means for detecting hook on/off status of an extension subscriber's telephone, and for supplying a current to said extension subscriber's telephone; memory means for accessing and recording data carried by a control signal; control processing means for generating command signals and said control signal, said control signal allocating a time slot according to signalling information from said extension subscriber matching means and accessing said memory means; complex frequency receiver means for converting a dialed signal, from the extension subscriber telephone connected to said subscriber matching circuit, into an altered signal for transmission to said control processing means; complex frequency transmitter means for generating a dual tone multifrequency in response to digit data output of said control processing means; switching circuit means for connecting a speech path of an office line with said extension subscriber matching means in response to said command signals; and office line matching means for interfacing an office line with said switching circuit means.

Claim 21

Dependent Claim 188 words

A keyphone exchange system for recovering a speech path of a per-engaged call upon restarting of said keyphone exchange system after occurrence of a system failure comprising: an extension subscriber matching means for detecting hook on/off status of an extension subscriber's telephone, and for supplying a current to said extension subscriber's telephone; memory means for accessing and recording data carried by a control signal; control processing means for generating command signals and said control signal, said control signal allocating a time slot according to signalling information from said extension subscriber matching means and accessing said memory means; complex frequency receiver means for converting a dialed signal, from the extension subscriber telephone connected to said subscriber matching circuit, into an altered signal for transmission to said control processing means; complex frequency transmitter means for generating a dual tone multifrequency in response to digit data output of said control processing means; switching circuit means for connecting a speech path of an office line with said extension subscriber matching means in response to said command signals; and office line matching means for interfacing an office line with said switching circuit means.

Claim 22

Dependent Claim 34 words

A keyphone exchange system as claimed in claim 18, further comprising a tone generator for supplying a plurality of tones to extension line subscriber telephones and office line subscribers through said switching circuit means.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1996-04-05	1996-10-05	1997-04-06	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	2000-04-05	2000-10-05	2001-04-06	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	2004-04-05	2004-10-05	2005-04-06	$7700.00	Window Closed / Lapsed

Method of recovering speech path of pre-engaged call on restarting keyphone exchange system

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