Claims
- 1. A method for synchronization of nodes in a VDSL system, the method comprising:connecting VDSL-nodes to a local station with optical fibers; connecting the VDSL-nodes to subscribers via a copper cable network including separate access connections and at least a common access connection; and synchronizing the VDSL-nodes to a common external time reference to reduce near end cross talk between the VDSL-nodes.
- 2. The method according to claim 1, wherein each VDSL-node includes a receiver for a synchronization signal and an internal oscillator to deliver a clock signal.
- 3. The method according to claim 2, wherein the internal oscillator comprises a rubidium oscillator.
- 4. The method according to claim 2, wherein the receiver comprises a satellite receiver.
- 5. The method according to claim 4, wherein synchronizing the VDSL-nodes comprises receiving signals, at the satellite receiver, from a plurality of satellites and averaging the received signals with respect to time and frequency to generate the synchronization signal.
- 6. The method according to claim 2, wherein the clock signal is used as sampling signal by each respective node.
- 7. The method according to claim 2, wherein the receiver is a GPS-receiver.
- 8. A method for synchronization of nodes in a VDSL system, the method comprising:connecting VDSL-nodes to a local station with optical fibers, each VDSL-node including a GPS-receiver for receiving at least one time-reference signal and generating a synchronization signal, and an associated internal oscillator to deliver a clock signal; connecting the VDSL-nodes to subscribers via a copper cable network including separate access connections and at least a common access connection; and synchronizing the VDSL-nodes to the at least one time-reference signals to reduce near end cross talk between the VDSL-nodes.
- 9. The method according to claim 8, wherein the internal oscillator comprises a rubidium oscillator.
- 10. The method according to claim 8, wherein the GPS-receiver receives time-reference signals from a plurality of satellites and averages the time-reference signals with respect to time and frequency to generate the synchronization signal.
- 11. The method according to claim 8, wherein the clock signal is used as sampling signal by each respective node.
- 12. A VDSL system comprising:VDSL-nodes connected to a local station via optical fibers, each VDSL-node including a GPS-receiver for receiving at least one time-reference signal and generating a synchronization signal, and an associated internal oscillator to deliver a clock signal; and a copper cable network including separate access connections and at least a common access connection connecting the VDSL-nodes to subscribers; the VDSL-nodes being synchronized to the at least one time-reference signal to reduce near end cross talk between the VDSL-nodes.
- 13. The system according to claim 12, wherein the internal oscillator comprises a rubidium oscillator.
- 14. The system according to claim 12, wherein the GPS-receiver receives time-reference signals from a plurality of satellites and averages the time-reference signals with respect to time and frequency to generate the synchronization signal.
- 15. The system according to claim 12, wherein the clock signal is used as sampling signal by each respective node.
Priority Claims (1)
Number |
Date |
Country |
Kind |
9702481 |
Jun 1997 |
SE |
|
Parent Case Info
This application is a 371 of PCT/SE98/01115 Jun. 10,1998.
PCT Information
Filing Document |
Filing Date |
Country |
Kind |
PCT/SE98/01115 |
|
WO |
00 |
Publishing Document |
Publishing Date |
Country |
Kind |
WO99/00928 |
1/7/1999 |
WO |
A |
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Zampatti |
Sep 1997 |
A |
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Kasurinen |
Nov 2001 |
B1 |
6373834 |
Lundh et al. |
Apr 2002 |
B1 |