US-12627332-B2 - Time-division multiplexing to reduce alien crosstalk in cables

Abstract

A transceiver transmits data via a first cable among a plurality of cables in a wired communication network, and selectively operates in one of (i) an active mode for transmitting data to a link partner via the first cable and (ii) a low power mode during which the transceiver quiets transmissions to conserve power. A crosstalk detector determines that transmission of data in the first cable is causing crosstalk in one or more second cables. A controller, in response to the crosstalk detector determining that transmission of the data in the first cable is causing crosstalk in one or more second cables, controls the transceiver to operate in the low power mode during a plurality of first time periods to reduce crosstalk in the one or more second cables during the plurality of first time periods.

Inventors

• Seid Alireza Razavi majomard
• David Shen

Assignees

• MARVELL ASIA PTE LTD

Dates

Publication Date

20260512

Application Date

20220524

Claims (20)

1. 1 . A first communication device in a wired communication network, the first communication device comprising: a first transceiver configured to transmit data via a first cable among a plurality of cables in the wired communication network, and to selectively operate according to a power saving mechanism that defines (i) an active mode for transmitting data and (ii) a low power mode defined by the power saving mechanism during which transmissions are quieted to conserve power; a second transceiver configured to transmit data via a second cable among the plurality of cables in the wired communication network, and to selectively operate according to the power saving mechanism that defines (i) the active mode and (ii) the low power mode; a crosstalk detector that is configured to determine that transmission of data in the first cable is causing crosstalk in the second cable; and a controller that is configured to, in response to the crosstalk detector determining that transmission of the data in the first cable is causing crosstalk in the second cable: control the first transceiver to operate in the low power mode defined by the power saving mechanism during a plurality of first time periods to reduce crosstalk in the second cable during the plurality of first time periods, and control the second transceiver to operate according to the power saving mechanism to restrict, to the plurality of first time periods, transmission of data via the second cable.
2. 2 . The first communication device of claim 1 , wherein the crosstalk detector is configured to: receive one or more signal quality measurements that correspond to (i) the second cable, and (ii) when transmission by the first transceiver via the first cable is occurring; and determine that transmission of data in the first cable is causing crosstalk in the second cable based on the one or more signal quality measurements.
3. 3 . The first communication device of claim 2 , wherein the crosstalk detector is configured to: receive one or more error rates of data transmitted in the second cable when transmission by the first transceiver via the first cable is occurring; and determine that transmission of data in the first cable is causing crosstalk in the second cable based on the one or more error rates of data transmitted in the second cable when transmission by the first transceiver via the first cable is occurring.
4. 4 . The first communication device of claim 2 , wherein the crosstalk detector is configured to: receive one or more signal level measurements that correspond to (i) when transmission by the second transceiver via the second cable is not occurring, and (ii) when transmission by the first transceiver via the first cable is occurring; and determine that transmission of data in the first cable is causing crosstalk in the second cable based on the one or more signal level measurements.
5. 5 . The first communication device of claim 1 , wherein the crosstalk detector is configured to: determine that transmission of data in the second cable is causing crosstalk in the first cable; and determine that transmission of data in the first cable is causing crosstalk in the second cable based on determining that transmission of data in the second cable is causing crosstalk in the first cable.
6. 6 . The first communication device of claim 1 , wherein the controller is configured to: control the first transceiver to operate in the active mode defined by the power saving mechanism outside of the plurality of first time periods.
7. 7 . The first communication device of claim 1 , wherein the controller is configured to: retrieve time-division multiplexing (TDM) scheduling information from a memory; and determine when the plurality of first time periods occur using the TDM scheduling information.
8. 8 . The communication device of claim 1 , wherein the controller is further configured to, in response to the crosstalk detector determining that transmission of the data in the first cable is causing crosstalk in the second cable: control the second transceiver to operate in the low power mode defined by the power saving mechanism during a plurality of second time periods that are different than the plurality of first time periods, and control the first transceiver to operate in the active mode defined by the power saving mechanism during the plurality of second time periods.
9. 9 . A method for mitigating effects of crosstalk in a wire communication network, the method comprising: transmitting, by a first transceiver of a first network device, data via a first cable among a plurality of cables; transmitting, by a second transceiver of the first network device, data via a second cable among the plurality of cables; determining, at circuitry associated with the first transceiver, that transmission of data in the first cable is causing crosstalk in the second cable; and in response to determining that transmission of the data in the first cable is causing crosstalk in the second cable, entering, with respect to the first transceiver, a low power mode defined by a power saving mechanism to quiet transmission by the first transceiver via the first cable during a plurality of first time periods to reduce crosstalk in the second cable during the plurality of first time periods; and in response to determining that transmission of the data in the first cable is causing crosstalk in the second cable, using the power saving mechanism, with respect to the second transceiver, to restrict, to the plurality of first time periods, transmission of data by the second transceiver via the second cable.
10. 10 . The method for mitigating effects of crosstalk of claim 9 , further comprising: measuring signal quality in the second cable when transmission by the first transceiver via the first cable is occurring; wherein determining that transmission of data in the first cable is causing crosstalk in the second cable is based on measurements of signal quality in the second cable when transmission by the first transceiver via the first cable is occurring.
11. 11 . The method for mitigating effects of crosstalk of claim 10 , wherein: measuring signal quality in the second cable when transmission by the first transceiver via the first cable is occurring comprises measuring one or more error rates of data transmitted in the second cable when transmission by the first transceiver via the first cable is occurring; and determining that transmission of data in the first cable is causing crosstalk in the second cable is based on the one or more error rates of data transmitted in the second cable when transmission by the first transceiver via the first cable is occurring.
12. 12 . The method for mitigating effects of crosstalk of claim 10 , wherein: measuring signal quality in the second cable when transmission by the first transceiver via the first cable is occurring comprises measuring one or more signal level measurements that correspond to (i) when transmission by the second transceiver via the second cable is not occurring, and (ii) when transmission by the first transceiver via the first cable is occurring; and determining that transmission of data in the first cable is causing crosstalk in the second cable is based on the one or more signal level measurements.
13. 13 . The method for mitigating effects of crosstalk of claim 9 , wherein determining that transmission of data in the first cable is causing crosstalk in the second cable comprises determining that transmission of data in the second cable is causing crosstalk in the first cable.
14. 14 . The method for mitigating effects of crosstalk of claim 9 , wherein: entering, with respect to the first transceiver, the low power mode defined by the power saving mechanism to quiet transmission by the first transceiver via the first cable during the plurality of first time periods to reduce crosstalk in the one or more second cables during the plurality of first time periods comprises causing, by control circuitry, the first transceiver to operate in the low power mode defined by the power saving mechanism during the plurality of first time periods; and the method further comprises operating the first transceiver in an active mode defined by the power saving mechanism outside of the plurality of first time periods.
15. 15 . The method for mitigating effects of crosstalk method of claim 9 , wherein quieting transmission by the first transceiver via the first cable during the plurality of first time periods to reduce crosstalk in the second cable during the plurality of first time periods comprises: retrieving time-division multiplexing (TDM) scheduling information from a memory; and determining when the plurality of first time periods occur using the TDM scheduling information.
16. 16 . The method for mitigating effects of crosstalk of claim 9 , further comprising: in response to determining that transmission of the data in the first cable is causing crosstalk in the second cable, entering, with respect to the second transceiver, the low power mode defined by the power saving mechanism to quiet transmission by the second transceiver via the second cable during a plurality of second time periods that are different than the plurality of first time periods; and in response to determining that transmission of the data in the first cable is causing crosstalk in the second cable, entering, with respect to the first transceiver, the active mode defined by the power saving mechanism during the plurality of second time periods.
17. 17 . A communication device in a wired communication network, the communication device comprising: a plurality of transceivers, each transceiver being configured to transmit data via a respective cable among a plurality of cables in the wired communication network, and to selectively operate according to a power saving mechanism that defines (i) an active mode for transmitting data to a respective link partner via the respective cable and (ii) a low power mode during which the respective transceiver quiets transmissions to conserve power, the plurality of transceivers including i) a first transceiver configured to communicate via a first cable among the plurality of cables, and il) a second transceiver configured to communicate via a second cable among the plurality of cables; and a controller that is configured to: receive crosstalk level information from the plurality of transceivers, the crosstalk level information indicating respective levels of alien crosstalk in respective cables among the plurality of cables, and in response to the crosstalk level information, control multiple transceivers among the plurality of transceivers to operate according to the power saving mechanism to reduce crosstalk, including: controlling the first transceiver to operate in the low power mode defined by the power saving mechanism during a plurality of first time periods to reduce crosstalk in the second cable during the plurality of first time periods, and control the second transceiver to control the second transceiver to operate according to the power saving mechanism to restrict, to the plurality of first time periods, transmission of data via the second cable.
18. 18 . The communication device of claim 17 , wherein the controller comprises a crosstalk detector that is configured to: receive a signal quality measurement regarding data transmitted in the second cable when transmission in the first cable is occurring; and determine that transmission of data in the first cable is causing crosstalk in the second cable based on the signal quality measurement.
19. 19 . The communication device of claim 18 , wherein the crosstalk detector is configured to: receive an error rate measurement regarding data transmitted in the second cable when transmission in the first cable is occurring; and determine that transmission of data in the first cable is causing crosstalk in the second cable based on the error rate measurement.
20. 20 . The communication device of claim 18 , wherein the crosstalk detector is configured to: receive a signal level measurement that corresponds to (i) when transmission in the second cable is not occurring, and (ii) when transmission in the first cable is occurring; and determine that transmission of data in the first cable is causing crosstalk in the second cable based on the signal level measurement.

Description

CROSS REFERENCES TO RELATED APPLICATIONS This application claims the benefit of U.S. Provisional Patent Application No. 63/192,438, entitled “Data Rate Optimization Using Energy Efficient Ethernet in High Alien Crosstalk Environments,” filed on May 24, 2021, the disclosure of which is hereby expressly incorporated herein by reference in its entirety. FIELD OF TECHNOLOGY The present disclosure relates generally to communication networks, and more particularly to Ethernet communications via cables. BACKGROUND One gigabit per second (1G) and slower Ethernet networks have proliferated in office buildings, schools, residential housing, etc., over the past two decades. 1G and slower Ethernet networks often employ Category 5 (Cat5) or Category 5e (Cat5e) twisted pair copper cables, comprising multiple twisted wire pairs. As a result, there is currently a large installed base 1G and slower Ethernet networks using Cat5 and Cat5e cables. The Institute for Electrical and Electronics Engineers (IEEE) published several standards for Ethernet networks that utilize 10 gigabit per second (10G) communications over optical and copper cabling in the early to mid-2000s. For example, the IEEE 802.3ae Standard (2002) defines a communication protocol for 10G Ethernet over optical fiber, and the IEEE 802.3ak Standard (2004) defines a communication protocol for 10G Ethernet over twin-axial cable. The IEEE 802.3an Standard (2006) defines a communication protocol for 10G Ethernet over copper twisted pair cable. The higher baud rate of 10G Ethernet as compared to 1G and slower Ethernet tends to cause more crosstalk between twisted pair copper cables. Cat5 and Cat5e cables generally are not rated for use with 10G Ethernet, mainly due to reduced performance caused by increased crosstalk between cables at the higher baud rate of 10G Ethernet. For example, Cat5 and Cat5e cables are rated up to 100 MHz, whereas 10G Ethernet over copper twisted pair cable (the IEEE 802.3an Standard) utilizes a baud rate of 800 Mega symbols per second (MSps). The minimum bandwidth required for a given baud rate is at least twice the baud rate. Thus, for 10G Ethernet, the minimum bandwidth required is 400 MHz. As discussed above, however, Cat5 and Cat5e are rated up to only 100 MHz. On the other hand, Category 6 (Cat6) and Category 6A (Cat6A) cables are designed for higher baud rates (and they mitigate crosstalk at the higher baud rates) and are rated for up to 250 MHz and 500 MHz, respectively. Thus, it is common for 10G Ethernet network deployments to use Cat6 or Cat6A (or even Category 7 (Cat7)) cables. Partly as a result of the high cost of replacing the large existing installed base of Cat5 and Cat5e cables with Cat6 or Cat6A (or even Cat7) cables, there is currently a relatively small number of 10G Ethernet networks in office buildings, schools, residential housing, etc. SUMMARY In an embodiment, a first communication device in a wired communication network comprises: a first transceiver configured to transmit data via a first cable among a plurality of cables in the wired communication network, and to selectively operate in one of (i) an active mode for transmitting data to a second communication device via the first cable and (ii) a low power mode during which the first transceiver quiets transmissions to conserve power; a crosstalk detector that is configured to determine that transmission of data in the first cable is causing crosstalk in one or more second cables among the plurality of cables; and a controller that is configured to, in response to the crosstalk detector determining that transmission of the data in the first cable is causing crosstalk in one or more second cables, control the first transceiver to operate in the low power mode during a plurality of first time periods to reduce crosstalk in the one or more second cables during the plurality of first time periods. In another embodiment, a method for mitigating effects of crosstalk in a wire communication network includes: transmitting, by a first transceiver of a first network device, data via a first cable among a plurality of cables; determining, at circuitry associated with the first transceiver, that transmission of data in the first cable is causing crosstalk in one or more second cables among the plurality of cables; and in response to determining that transmission of the data in the first cable is causing crosstalk in one or more second cables, quieting transmission by the first transceiver via the first cable during a plurality of first time periods to reduce crosstalk in the one or more second cables during the plurality of first time periods. In yet another embodiment, a communication device in a wired communication network comprises: a plurality of transceivers, each transceiver being configured to transmit data via a respective cable among a plurality of cables in the wired communication network, and to selectively operate in one of (i) an active mode for transmitting data