Method and system for compensating signal propagation delay
First Claim
1. A method of compensating for signal propagation delay in a data communications network comprising a central control node and one or more remote subscriber nodes, the method comprising the steps of:
- a) designating a registration time slot per frame in which the remote subscriber nodes may each first transmit a first transmission;
b) transmitting said first transmission from the remote subscriber nodes at the start of the registration time slot;
c) measuring one or more respective time periods from the start of the registration time slot to the receipt at the central control node of each first transmission from each remote subscriber node, each time period corresponding to a respective propagation delay for transmission of signal from one of the remote subscriber nodes to the central control node, by setting a value in a countdown timer, said value corresponding to a minimum signal propagation delay, starting said countdown timer to count down from said value at the star of the registration time slot, and reading the value from said timer at the moment when each respective first transmission from the respective remote subscriber node is received at the central control node, wherein said read values are then directly indicated to the respective remote subscriber nodes as said time periods;
d) indicating to each respective remote subscriber node the respective measured time period for that node, wherein each remote subscriber node then uses its respective measured time period to compensate for signal propagation delay when transmitting subsequent data traffic to the central control node; and
e) using the respective signal propagation delays in each remote subscriber terminal to artificially simulate that each remote subscriber terminal is at the same distance from the central control node as every other remote subscriber terminal.
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Accused Products
Abstract
Propagation delay compensation in a wireless network comprising a central access point and multiple subscriber terminals is achieved by defining a registration time slot in which new subscriber terminals must first transmit network registration signals to the access point. The subscriber terminals by default transmit at the start of the time slot, and the access point times the delay from the start of the slot to the receipt of the subscriber terminal registration request, and then transmits this information back to the subscriber terminal. In all subsequent transmissions the subscriber terminal uses this information to delay its transmissions to compensate for differences in signal propagation delay between each subscriber terminal.
71 Citations
16 Claims
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1. A method of compensating for signal propagation delay in a data communications network comprising a central control node and one or more remote subscriber nodes, the method comprising the steps of:
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a) designating a registration time slot per frame in which the remote subscriber nodes may each first transmit a first transmission;
b) transmitting said first transmission from the remote subscriber nodes at the start of the registration time slot;
c) measuring one or more respective time periods from the start of the registration time slot to the receipt at the central control node of each first transmission from each remote subscriber node, each time period corresponding to a respective propagation delay for transmission of signal from one of the remote subscriber nodes to the central control node, by setting a value in a countdown timer, said value corresponding to a minimum signal propagation delay, starting said countdown timer to count down from said value at the star of the registration time slot, and reading the value from said timer at the moment when each respective first transmission from the respective remote subscriber node is received at the central control node, wherein said read values are then directly indicated to the respective remote subscriber nodes as said time periods;
d) indicating to each respective remote subscriber node the respective measured time period for that node, wherein each remote subscriber node then uses its respective measured time period to compensate for signal propagation delay when transmitting subsequent data traffic to the central control node; and
e) using the respective signal propagation delays in each remote subscriber terminal to artificially simulate that each remote subscriber terminal is at the same distance from the central control node as every other remote subscriber terminal. - View Dependent Claims (2, 3, 4, 5, 6)
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7. A system for compensating for signal propagation delay in a data communications network comprising a central control node and one or more remote subscriber nodes, said system comprising:
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a) means for designating a registration time slot per frame in which the remote subscriber nodes may each first transmit a first transmission;
b) means for transmitting said first transmission from the remote subscriber nodes at the start of the registration time slot;
c) means for measuring one or more respective time periods from the start of the registration time slot to the receipt at the central control node of each first transmission from each remote subscriber node, each time period corresponding to a respective propagation delay for transmission of signal from one of the remote subscriber nodes to the central control node, comprising means for setting a value in a countdown timer corresponding to a minimum signal propagation delay, means for starting said countdown timer to count down from said value at the start of registration time slot, and means for reading the value from said timer at the moment when each respective first transmission from each respective remote subscriber node is received at the central control node, wherein said read values are then directly indicated to each respective remote subscriber nodes as said time periods; and
d) means for indicating to each respective remote subscriber node the respective measured time period for that node, wherein each remote subscriber node then uses its respective measured time period to compensate for signal propagation delay when transmitting subsequent data traffic to the central control node; and
e) means for using the respective signal propagation delays in each remote subscriber terminal to artificially simulate that each remote subscriber terminal is at the same distance from the central control node as every other subscriber terminal. - View Dependent Claims (8, 9, 10, 11, 12)
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13. A method of compensating for signal propagation delay in a data communications network comprising a central control node and one or more remote subscriber nodes, comprising the steps of:
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a) measuring the respective signal propagation delays for each subscriber node by;
setting a value in a countdown timer, said value corresponding to a minimum signal propagation delay, starting said countdown timer to count down from said value at the start of the registration time slot, and reading the value from said timer at the moment when each respective first transmission from the respective remote subscriber node is received at the central control node, wherein said read values are then directly indicated to the respective remote subscriber nodes as said time periods; and
b) using respective signal propagation delays in each remote subscriber terminal to artificially simulate that each remote subscriber terminal is at the same distance from the central control node as every other remote subscriber terminal. - View Dependent Claims (14)
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15. A system for compensating for signal propagation delay in a data communications network comprising a central control node and one or more remote subscriber nodes, said system comprising:
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a) measuring means for measuring the respective signal propagation delays for each subscriber node comprising means for setting a value in a countdown timer, said value corresponding to a minimum signal propagation delay, means for starting said countdown timer to count down from said value at the start of the registration time slot, and means for reading the value from said timer at the moment when each respective first transmission from the respective remote subscriber node is received at the central control node, wherein said read values are then directly indicated to the respective remote subscriber nodes as said time periods; and
b) means for using the respective signal propagation delays in each remote subscriber terminal to artificially simulate that each remote subscriber terminal is at the same distance from the central control node as every other subscriber terminal. - View Dependent Claims (16)
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Specification