Dynamic subcarrier utilization and intelligent transmission scheduling

• US 8,942,301 B2
• Filed: 07/31/2012
• Issued: 01/27/2015
• Est. Priority Date: 03/23/2012
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Hui, Jonathan W., Vasseur, Jean-Philippe, Hong, Wei
• Primary Examiner(s): Kim, Kevin
• Application Number:
  US13/563,524
• Publication Number:
  US 20130251054A1
• Time in Patent Office: 910 Days
• Field of Search: 375/260
• US Class Current: 375/260
• CPC Class Codes: H04B 2203/5416 by adding signals to the wave form of the power source
• CPC Class Codes: H04B 3/54 Systems for transmission via power distribution lines
• CPC Class Codes: H04J 11/00 Orthogonal multiplex systems, e.g. using WALSH codesH04J13/00 takes precedence
• CPC Class Codes: H04L 27/0006 Assessment of spectral gaps suitable for allocating digitally modulated signals, e.g. for carrier allocation in cognitive radio for spectrum sharing between different networks H04W16/14
• CPC Class Codes: H04L 27/2601 Multicarrier modulation systems
• CPC Class Codes: H04L 5/0007 the frequencies being orthogonal, e.g. OFDM(A), DMT
• CPC Class Codes: H04L 5/003 Arrangements for allocating sub-channels of the transmission path
• CPC Class Codes: H04L 5/0032 Distributed allocation, i.e. involving a plurality of allocating devices, each making partial allocation
• CPC Class Codes: H04L 5/0033 each allocating device acting autonomously, i.e. without negotiation with other allocating devices
• CPC Class Codes: H04L 5/0037 Inter-user or inter-terminal allocation
• CPC Class Codes: H04L 5/0044 allocation of payload
• CPC Class Codes: H04L 5/0064 Rate requirement of the data, e.g. scalable bandwidth, data priority
• CPC Class Codes: H04L 5/0094 Indication of how sub-channels of the path are allocated
• CPC Class Codes: H04W 72/0453 Resources in frequency domain, e.g. a carrier in FDMA
• CPC Class Codes: Y02D 30/70 in wireless communication networks

Abstract

In one embodiment, a transmitting device monitors transmission activity of each of a plurality of subcarriers in a communication network, and determines a set of unutilized subcarriers of the plurality of subcarriers. As such, the transmitting device may then transmit a data frame on one or more of the unutilized subcarriers to a receiving device while transmission activity is present on one or more utilized subcarriers within the network. In another embodiment, the transmitting device may also determine timing information associated with the transmission activity, and may correspondingly schedule the transmitting to optimize network performance based on the timing information.

Claims

1. A method, comprising:

monitoring transmission activity of each of a plurality of subcarriers in a communication network;

determining a set of unutilized subcarriers of the plurality of subcarriers and timing information associated with the transmission activity;

transmitting a data frame on one or more of the unutilized subcarriers to a receiving device while transmission activity is present on one or more utilized subcarriers within the network based on the timing information; and

scheduling the transmitting to optimize network performance based on the timing information.

2. The method as in claim 1, wherein scheduling comprises:

transmitting the data frame substantially immediately in response to availability of the one or more of the unutilized subcarriers.

3. The method as in claim 1, wherein scheduling comprises:

transmitting the data frame in response to availability of a sufficient number of unutilized subcarriers to meet a determined transmission timing.

4. The method as in claim 1, wherein scheduling comprises:

determining a first finish time associated with transmitting the data frame substantially immediately in response to availability of the one or more of the unutilized subcarriers;

determining a second finish time associated with transmitting the data frame in response to availability of a sufficient number of unutilized subcarriers to meet a determined transmission timing; and

selecting whether to transmit the data frame substantially immediately or in response to availability of a sufficient number of unutilized subcarriers based on the quickest finish time of the first and second finish times.

5. The method as in claim 1, wherein scheduling comprises:

initiating the transmitting only when the transmitting will finish before a current active transmission.

6. The method as in claim 5, wherein scheduling comprises:

detecting multiple active transmissions; and

, in response,

initiating the transmitting only when the transmitting will finish before the current active transmission of the multiple active transmissions that is expected to finish first.

7. The method as in claim 1, wherein scheduling comprises:

limiting frame transmissions on any subcarrier to within a single timeslot shared across all subcarriers.

8. The method as in claim 1, wherein transmitting comprises:

transmitting a preamble and physical (PHY) header of the data frame on each individual subcarrier with information as to which one or more subcarriers will be used for the transmitting, such that decoding any individual subcarrier allows the receiving device to determine which one or more subcarriers will be used for the transmitting.

9. The method as in claim 1, further comprising:

grouping subcarriers into sub-channels;

wherein monitoring transmission activity of each of the plurality of subcarriers comprises monitoring transmission activity of each of a plurality of sub-channels;

wherein determining the set of unutilized subcarriers of the plurality of subcarriers comprises determining a set of unutilized sub-channels of the plurality of sub-channels; and

wherein transmitting the data frame on one or more of the unutilized subcarriers comprises transmitting the data frame on one or more of the unutilized sub-channels to the receiving device while transmission activity is present on one or more utilized sub-channels.

10. The method as in claim 9, wherein transmitting comprises:

transmitting a preamble and physical (PHY) header of the data frame on each individual sub-channel with information as to which one or more sub-channels will be used for the transmitting, such that decoding any individual sub-channel allows the receiving device to determine which one or more sub-channels will be used for the transmitting.

11. The method as in claim 1, further comprising:

selecting, based on an optimal tone map, an optimal subcarrier from the set of unutilized subcarriers; and

transmitting the data frame on the optimal subcarrier to the receiving device.

12. An apparatus, comprising:

a network interface adapted to communicate data frames over a network using one or more of a plurality of subcarriers in a communication network;

a processor coupled to the network interfaces and adapted to execute one or more processes; and

a memory configured to store a process executable by the processor, the process when executed operable to;

monitor transmission activity of each of a plurality of subcarriers in the communication network;

determine a set of unutilized subcarriers of the plurality of subcarriers and timing information associated with the transmission activity;

transmit a data frame on one or more of the unutilized subcarriers to a receiving device while transmission activity is present on one or more utilized subcarriers within the network based on the timing information; and

schedule the transmission to optimize network performance based on the timing information.

13. The apparatus as in claim 12, wherein the process when executed to schedule is further operable to:

transmit the data frame substantially immediately in response to availability of the one or more of the unutilized subcarriers.

14. The apparatus as in claim 12, wherein the process when executed to schedule is further operable to:

transmit the data frame in response to availability of a sufficient number of unutilized subcarriers to meet a determined transmission timing.

15. The apparatus as in claim 12, wherein the process when executed to schedule is further operable to:

determine a first finish time associated with transmitting the data frame substantially immediately in response to availability of the one or more of the unutilized subcarriers;

determine a second finish time associated with transmitting the data frame in response to availability of a sufficient number of unutilized subcarriers to meet a determined transmission timing; and

select whether to transmit the data frame substantially immediately or in response to availability of a sufficient number of unutilized subcarriers based on the quickest finish time of the first and second finish times.

16. The apparatus as in claim 12, wherein the process when executed to schedule is further operable to:

initiate the transmitting only when the transmitting will finish before a current active transmission.

17. The apparatus as in claim 12, wherein the process when executed to schedule is further operable to:

limit frame transmissions on any subcarrier to within a single timeslot shared across all subcarriers.

18. The apparatus as in claim 12, wherein the process when executed to transmit is further operable to:

transmit a preamble and physical (PHY) header of the data frame on each individual subcarrier with information as to which one or more subcarriers will be used for the transmitting, such that decoding any individual subcarrier allows the receiving device to determine which one or more subcarriers will be used for the transmitting.

19. The apparatus as in claim 12, wherein the process when executed is further operable to:

group subcarriers into sub-channels;

wherein monitoring transmission activity of each of the plurality of subcarriers comprises monitoring transmission activity of each of a plurality of sub-channels;

wherein determining the set of unutilized subcarriers of the plurality of subcarriers comprises determining a set of unutilized sub-channels of the plurality of sub-channels; and

wherein transmitting the data frame on one or more of the unutilized subcarriers comprises transmitting the data frame on one or more of the unutilized sub-channels to the receiving device while transmission activity is present on one or more utilized sub-channels.

20. The apparatus as in claim 19, wherein the process when executed to transmit is further operable to:

transmit a preamble and physical (PHY) header of the data frame on each individual sub-channel with information as to which one or more sub-channels will be used for the transmitting, such that decoding any individual sub-channel allows the receiving device to determine which one or more sub-channels will be used for the transmitting.

21. The apparatus as in claim 12, wherein the process when executed is further operable to:

select, based on an optimal tone map, an optimal subcarrier from the set of unutilized subcarriers; and

transmit the data frame on the optimal subcarrier to the receiving device.

22. A tangible, non-transitory, computer-readable media having software encoded thereon, the software when executed by a processor operable to:

monitor transmission activity of each of a plurality of subcarriers in a communication network;

determine a set of unutilized subcarriers of the plurality of subcarriers and timing information associated with the transmission activity; and

transmit a data frame on one or more of the unutilized subcarriers to a receiving device while transmission activity is present on one or more utilized subcarriers within the network based on the timing information; and

schedule the transmission to optimize network performance based on the timing information.