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US 9,426,762 B2Granted
Timing synchronization for networks with radio links
AssigneeMicrosemi Communications, Inc.
InventorsKristian Ehlers, Brian Branscomb, Thomas Kirkegaard Joergensen
Life of this patent
Estimating the term…
Abstract
Precision Timing Protocol (PTP) related functions for use in packet communications carried in part by a microwave communications link include setting of time of day values across the microwave link and providing transparent clock functions. The PTP functions may be used for synchronizing radio base stations in a cellular network. The transparent clock can bridge Ethernet switches associated with microwave stations providing the microwave communications link.
Claims10
A method of performing timing related processing in a packet-based network communications over a communications link, the method comprising:
- synchronizing a clock of a first Ethernet switch with a clock of a second Ethernet switch separated by a microwave communications link, the first Ethernet switch being part of a first microwave station and the second Ethernet switch being part of a second microwave station;
- determining a time of arrival of a packet at the first Ethernet switch using a first time of day (TOD) domain, said first TOD domain associated with the first Ethernet switch;
- determining a time of departure of the packet from the first Ethernet switch utilizing the first TOD domain;
- determining a time of departure of the packet from the first microwave station utilizing a second TOD domain, said second TOD domain associated with circuitry performing communication link functions of the microwave communications link;
- transmitting the packet, including information regarding the determined time of departure of the packet from the first microwave station utilizing the second TOD domain, from the first microwave station to the second microwave station;
- determining a time of arrival of the packet at the second microwave station utilizing the second TOD domain;
- determining a time of arrival of the packet at the second Ethernet switch utilizing the first TOD domain;
- determining a time of departure of the packet from the second Ethernet switch utilizing the first TOD domain;
- and
- setting a correction field of the packet to a value based on at least the determined time of departure of the packet from the first microwave station utilizing the second TOD domain, the determined time of arrival of the packet at the first Ethernet switch utilizing the first TOD domain and one at least one of:
- the determined time of departure of the packet from the first Ethernet switch utilizing the first TOD domain;
- the determined time of arrival of the packet at the second microwave station utilizing the second TOD domain;
- the determined time of arrival of the packet at the second Ethernet switch utilizing the first TOD domain;
- and
- the determined time of departure of the packet from the second Ethernet switch utilizing the first TOD domain.
12 more elements
A communication system comprising:
- a first microwave station comprising a first packet handling circuitry;
- and
- a second microwave station comprising a second packet handling circuitry, the second packet handling circuitry separated from the first packet handling circuitry by a microwave communications link between the first and second microwave stations, a clock of the first packet handling circuitry synchronized with a clock of the second packet handling circuitry,
- the first packet handling circuitry configured to determine a time of arrival of a packet at the first packet handling circuitry utilizing a first time of day (TOD) domain, and further configured to determine a time of departure of the packet from the first packet handling circuitry utilizing the first TOD domain, said first TOD domain associated with the first packet handling circuitry,
- a circuitry performing communication link functions of the microwave communications link of said first microwave station configured to determine a time of departure of the packet from the first microwave station utilizing a second TOD, said second TOD domain associated with the circuitry performing communication link functions of the microwave communications link,
- the circuitry performing communication link functions of the microwave communications link further configured to transmit the packet, including information regarding the determined time of departure of the packet from the first microwave station utilizing the second TOD domain, from the first microwave station to the second microwave station, the circuitry performing communication link functions of the microwave communications link of the second microwave station configured to determine a time of arrival of the packet at the second microwave station utilizing the second TOD domain,
- the second packet handling circuitry configured to determine a time of arrival of the packet at the second packet handling circuitry utilizing the first TOD domain and further configured to determine a time of departure of the packet from the second packet handling circuitry utilizing the first TOD domain,
- the second packet handling circuitry further configured to set a correction field of the packet to a value based on at least the determined time of departure of the packet from the first microwave station using the second TOD domain and the determined time of arrival of the packet at the first packet handling circuitry utilizing the first TOD domain and further based on at least one of:
- the determined time of departure of the packet from the first packet handling circuitry utilizing the first TOD domain;
- the determined time of arrival of the packet at the second microwave station utilizing the second TOD domain;
- the determined time of arrival of the packet at the second packet handling circuitry utilizing the first TOD domain;
- and
- the determined time of departure of the packet from the second packet handling circuitry utilizing the first TOD domain.
10 more elements
Dependencies are inferred from the claim text.