US 2011/0211834 A1 · SCHEDULING WDM PON WITH TUNABLE LASERS WITH DIFFERENT TUNING TIMES

Abstract

Technologies are generally described for network traffic scheduling in a wavelength division multiplexing (WDM) passive optical network (PON). Dynamic wavelength assignment and time allocation in hybrid WDM/TDM PONs with tunable lasers as optical light generators is accomplished by mapping the scheduling into a multi-processor scheduling problem with wavelength channels as machines and ONU requests as jobs. Wavelengths may be considered as parallel identical machines. Taking laser tuning time into consideration preemptive and non-preemptive scheduling with the objective of minimizing the latest job completion time is computed employing a number of heuristic algorithms. The algorithms compute two extreme cases of zero and infinity laser tuning time, respectively. Using the results from these two extreme cases, the heuristic scheduling schemes for the case of arbitrary laser tuning time yield close average latest job completion times for both schedule types.

Claims23

Dependent claims

A method for allocating network traffic requests on multiple wavelength optical network units (ONUs) of a wavelength division multiplexing (WDM) passive optical network (PON), the method comprising:

determining whether an allocation is for a preemptive schedule or a non-preemptive schedule;
for the preemptive schedule, assigning wavelengths to requests;
sorting the requests and the wavelengths;
postponing the requests by a laser tuning time associated with each ONU;
and
optimizing the preemptive schedule by filling in idle times.

3 more elements

An apparatus for allocating network traffic requests on multiple wavelength optical network units (ONUs) of a wavelength division multiplexing (WDM) passive optical network (PON), comprising:

a memory configured to store instructions and also store network information data associated with the WDM PON;
a processor coupled to the memory, wherein the processor is adapted to execute the instructions, which when executed configure the processor to:
determine whether an allocation is for a preemptive schedule or a non-preemptive schedule;
for the preemptive schedule:
assign wavelengths to requests;
sort the requests in descending order of a size of each request and the wavelengths in ascending order of an available time for each wavelength;
for the non-preemptive schedule:
sort the requests in descending order of a size of each request and the wavelengths in ascending order of an available time for each wavelength;
assign each request to the wavelengths to which the request temporally fits;
postpone the requests by a laser tuning time associated with each ONU;
and
optimize the schedules by filling in idle times.

9 more elements

A computer-readable storage medium having instructions stored thereon for allocating network traffic requests on multiple wavelength optical network units (ONUs) of a wavelength division multiplexing (WDM) passive optical network (PON), the instructions comprising:

determining whether an allocation is for a preemptive schedule or a non-preemptive schedule;
for the preemptive schedule:
assigning wavelengths to requests;
sorting the requests in descending order of a size of each request and the wavelengths in ascending order of an available time for each wavelength;
for the non-preemptive schedule:
sorting the requests in descending order of a size of each request and the wavelengths in ascending order of an available time for each wavelength;
assigning each request to the wavelengths to which the request temporally fits;
postponing all requests and a last request on each wavelength by the laser tuning time associated with an ONU currently being allocated;
and
reducing an overall latest job completion time.

7 more elements

Dependencies are inferred from the claim text.

Scheduling wdm pon with tunable lasers with different tuning times

Life of this patent

Scheduling wdm pon with tunable lasers with different tuning times

Life of this patent

Abstract

Claims23