Temperature compensation for transmission between nodes coupled by a unidirectional fiber ring
First Claim
1. A method for monitoring transmissions over a unidirectional optical fiber loop coupling multiple nodes wherein a first node is a main base station unit, including processing circuitry and a central clock source, and the one or more other nodes are remote base station units including radio transceiving circuitry for communicating over a radio interface with a mobile radio terminal, comprising the steps of:
- measuring a round trip delay time for a signal sent from said first node to travel around the unidirectional optical fiber loop and be received at the first node;
using the measured round trip delay time to account for temperature induced affects on signal transmissions over the unidirectional optical fiber loop; and
wherein the mobile terminal determines one or more round trip times (RTTs), said step further comprises;
the mobile terminal sending an RTT message to one of the remote base station units over the radio interface;
the one remote base station unit sending the RTT message to the main base station via the unidirectional optical fiber loop;
the main base station unit modifying the RTT message with a recently determined round trip delay time that accounts for temperature induced delay variations in the loop;
the main base station unit sending the modified RTT message to the remote base station via the unidirectional optical fiber loop;
the remote base station unit transmitting the modified RTT message to the mobile terminal over the radio interface; and
the mobile terminal determining the RTT based on the modified RTT message.
6 Assignments
0 Petitions
Accused Products
Abstract
Transmissions over a unidirectional optical fiber coupling multiple nodes are compensated for temperature-induced effects. A round-trip delay time is determined for a signal sent from a first node to travel around the unidirectional optical fiber loop and be received back at the first node. That measured round-trip delay time is then used to account for temperature-induced effects on signal transmissions over the unidirectional optical fiber loop. This temperature compensation is particularly beneficial in applications that require a high level of timing accuracy.
30 Citations
22 Claims
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1. A method for monitoring transmissions over a unidirectional optical fiber loop coupling multiple nodes wherein a first node is a main base station unit, including processing circuitry and a central clock source, and the one or more other nodes are remote base station units including radio transceiving circuitry for communicating over a radio interface with a mobile radio terminal, comprising the steps of:
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measuring a round trip delay time for a signal sent from said first node to travel around the unidirectional optical fiber loop and be received at the first node; using the measured round trip delay time to account for temperature induced affects on signal transmissions over the unidirectional optical fiber loop; and wherein the mobile terminal determines one or more round trip times (RTTs), said step further comprises; the mobile terminal sending an RTT message to one of the remote base station units over the radio interface; the one remote base station unit sending the RTT message to the main base station via the unidirectional optical fiber loop; the main base station unit modifying the RTT message with a recently determined round trip delay time that accounts for temperature induced delay variations in the loop; the main base station unit sending the modified RTT message to the remote base station via the unidirectional optical fiber loop; the remote base station unit transmitting the modified RTT message to the mobile terminal over the radio interface; and the mobile terminal determining the RTT based on the modified RTT message. - View Dependent Claims (2, 3, 4, 5, 6, 7, 8, 9, 10, 11)
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12. Apparatus for use in monitoring transmissions over a unidirectional optical fiber loop coupling multiple nodes wherein a first node is a main base station unit and the one or more other nodes are remote base station units including radio transceiving circuitry for communicating over a radio interface with a mobile radio terminal, comprising electronic circuitry operative to:
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measure a round trip delay time for a signal sent from a first node to travel around the unidirectional optical fiber loop and be received at the first node; and
,account for temperature induced affects on signal transmissions over the unidirectional optical fiber loop using the measured round trip delay time; and determining one or more round trip times (RTTs) wherein the mobile terminal is configured to send an RTT message to one of the remote base station units over the radio interface; the one remote base station unit is configured to send the RTT message to the main base station unit via the unidirectional optical fiber loop; the main base station unit is configured to modify the RTT message with a recently determined round trip delay time that accounts for temperature induced delay variations in the loop; the main base station unit is configured to send the modified RTT message to the remote base station unit via the unidirectional optical fiber loop; the remote base station unit is configured to transmit the modified RTT message to the mobile terminal over the radio interface; and
,the mobile terminal is configured to determine the RTT based on the modified RTT message. - View Dependent Claims (13, 14, 15, 16, 17, 18, 19, 20, 21, 22)
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Specification