SCHEDULING DEVICE

• US 20110200328A1
• Filed: 09/12/2008
• Published: 08/18/2011
• Est. Priority Date: 09/12/2008
• Status: Active Grant

• Current Assignee: Telefonaktiebolaget LM Ericsson
• Original Assignee: Telefonaktiebolaget LM Ericsson
• Inventors: In De Betou, Einar, Ohlen, Peter
• Granted Patent: US 8,849,121 B2
• Time in Patent Office: Days
• US Class Current: 398/38
• CPC Class Codes: H04J 3/0682 by delay compensation, e.g. by compensation of propagation delay or variations thereof, by ranging
• CPC Class Codes: H04J 3/14 Monitoring arrangements for SDH/SONET rings H04J3/085
• CPC Class Codes: H04J 3/1694 Allocation of channels in TDM/TDMA networks, e.g. distributed multiplexers Passive Optical Networks H04Q11/0062
• CPC Class Codes: H04L 5/0003 Two-dimensional division time-code division H04J11/00, H04J13/00; for time-space division H04B7/0413, H04B7/0697
• CPC Class Codes: H04Q 11/0067 Provisions for optical access or distribution networks, e.g. Gigabit Ethernet Passive Optical Network (GE-PON), ATM-based Passive Optical Network (A-PON), PON-Ring
• CPC Class Codes: H04Q 2011/0064 Arbitration, scheduling or medium access control aspects

Abstract

A control device (13) for scheduling the transmission of signals from a plurality of transmitters (14, 15, 16, 17, 18, 19, 20, 21). The control device (13) comprises an evaluation element (22) arranged to determine the power level of the signals received from each of the transmitters and a scheduling element (23) adapted to determine a transmit schedule comprising the order that the plurality of transmitters should transmit based on the power levels of the signals received from the transmitters (14, 15, 16, 17, 18, 19, 20, 21). A method of operation and a node incorporating the control device is also disclosed.

Claims

1. A control device for scheduling the transmission of signals from a plurality of transmitters, the control device comprising:

an evaluation element arranged to determine the power level of the signals received from each of the transmitters; and

a scheduling element adapted to determine a transmit schedule comprising an order that the plurality of transmitters should transmit based on the power levels of the signals received from the transmitters.

2. A control device according to claim 1, wherein the scheduling element is further adapted to determine the transmit schedule to define an order in which the transmitters transmit such that the power levels of the signals received from consecutive transmitters is within a predetermined range.

3. A control device according to claim 1, wherein scheduling element is further adapted to determine the transmit schedule to define an order in which the transmitters transmit such that the change in power levels of the signals received from consecutive transmitters is minimised.

4. A control device according to claim 1, wherein the scheduling element is adapted to assign each of the transmitters to one of a predetermined number of groups based on the signal power of the signal received from each transmitter, each group covering a unique range of signal powers, and wherein the scheduling element determines the transmit schedule such that a subsequent transmitter is selected from the same group as the previous transmitter or an adjacent group.

5. A control device according to claim 1, wherein the evaluation element is arranged to measure the input power received from each transmitter.

6. A control device according to claim 1, wherein the evaluation element is adapted to determine the power levels from information gathered during a ranging process.

7. A control device according to claim 1, further comprising:

an instructing element adapted to instruct the transmitters to transmit in accordance with the transmit schedule.

8. A control device according to claim 1, wherein the instructing element utilises existing protocols to instruct the transmitters.

9. A control device according to claim 1, wherein the scheduling element specifies in the transmit schedule, the length of a preamble portion that each of the transmitters should transmit prior to transmitting a data portion.

10. A control device according to claim 1, wherein the plurality of transmitters comprise optical network terminal nodes of a passive optical network and the control device is associated with an optical receiver of an optical line termination node.

11. A method for scheduling the transmission of signals from a plurality of transmitters, the method including the steps of:

a) determining the power level of the signals received from each of the transmitters; and

b) determining a transmit schedule comprising an order that the plurality of transmitters should transmit based on the power levels of the signals received from the transmitters.

12. A method according to claim 11, further comprising after step b):

c) instructing the transmitters to transmit in accordance with the transmit schedule.

13. A method according to claim 11 wherein step b) comprises defining an order in which the transmitters transmit such that the power levels of the signals received from consecutive transmitters is within a predetermined range.

15. A communications network comprising a node that is configured to operate as defined in claim 13.

14. A node for use in a communications network, the node comprising:

a receiver configured to receive signals from a plurality of transmitters; and

a control device configured to schedule the transmission of signals from the plurality of transmitters, wherein the control device comprises;

an evaluation element arranged to determine the power level of the signals received from each of the transmitters; and

a scheduling element adapted to determine a transmit schedule comprising an order that the plurality of transmitters should transmit based on the power levels of the signals received from the transmitters.

16. A communications network comprising a node that is configured to operate as defined in claim 14, wherein the evaluation element is adapted to determine the power levels from information gathered during a ranging process of the network.