Interference suppressing for optical wireless networks
AssigneeSignify Holding B.V.
InventorAndries Van Wageningen
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Abstract
For time-division based wireless optical networks, it is important to keep neighboring coordinators synchronized to a common time base, in order to avoid interference to a network device located in the overlapping area of such neighboring coordinators. However, given that the common time base is located remotely, there is still timing synchronization uncertainty remaining at a coordinator side. A novel auxiliary scheduler subsystem, and the related methods and systems, are disclosed in this invention. By reserving time margins in the allocated time slots by the auxiliary scheduler subsystem, interference due to timing synchronization uncertainty is reduced.
Claims14
An auxiliary scheduler for reducing interference in an optical wireless communication (OWC) network having a line-of-sight character, the OWC network comprising at least two coordinators and a plurality of network devices selectively associated to and synchronized with a respective one of the coordinators, and wherein the at least two coordinators and the plurality of network devices share a same optical wireless medium of the OWC network via a time-division multiple access (TDMA) approach by dividing the wireless medium into consecutive time slots, at least part of the auxiliary scheduler co-located with a coordinator;
- wherein the auxiliary scheduler is configured:
- to determine a first margin representing a time-interval needed to tolerate a deviation of a local time of the coordinator from a remote timing reference due to timing synchronization uncertainty of the coordinator against the remote timing reference;
- to reserve the first margin within an allocated time slot of the coordinator, which is adjacent to a neighboring time slot allocated to another coordinator than the allocated time slot;
- to determine a second margin representing another time-interval needed to tolerate timing synchronization uncertainty between the coordinator and any other coordinator in the OWC network;
- and
- to reserve the second margin within the allocated time slot of the coordinator, which is adjacent to another neighboring time slot, when information on allocation of the other neighboring time slot is unavailable at the auxiliary scheduler subsystem.
A method for reducing interference in an optical wireless communication (OWC) network having a line-of-sight character using a time-division multiple access (TDMA) approach, the OWC network comprising at least two coordinators and a plurality of network devices selectively associated to and synchronized with a respective one of the coordinators, and wherein the at least two coordinators and the plurality of network devices share a same wireless medium of the OWC network via a TDMA approach by dividing the wireless medium into consecutive time slots,
- the method comprising:
- determining a first margin representing a time-interval needed to tolerate a deviation of a local time of a coordinator from a remote timing reference due to timing synchronization uncertainty of the coordinator against the remote timing reference;
- reserving the first margin within an allocated time slot of the coordinator, which is adjacent to a neighboring time slot allocated to another coordinator than the allocated time slot;
- determining a second margin representing another time-interval needed to tolerate timing synchronization uncertainty between the coordinator and any other coordinator in the OWC network;
- and
- reserving the second margin within the allocated time slot of the coordinator, which is adjacent to another neighboring time slot, when information on allocation of the other neighboring time slot is unavailable at the auxiliary scheduler subsystem.
Dependencies are inferred from the claim text.