Grant Frame Duration Field Redefinition for Dynamic TxOP Rescheduling
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Solution Overview
Problem
Current definitions of fields and subfields in the grant frame according to IEEE 802.11ad-2012 are not sufficient for efficient dynamic allocation in certain scenarios, particularly in rescheduling the remainder of a Transmit Opportunity (TxOP) or Service Period (SP), as they do not allow for clear indication of when the allocated time starts.
Innovation Solution
The proposed solution involves using a grant frame with a predefined value in the Allocation Duration field to indicate that the remainder of a TxOP or SP should be rescheduled, and dynamically allocating time within existing TxOP or SP without adding to it, by setting the duration field to point to the end of the allocated time, and using a reserved value to indicate rescheduling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Adaptability or versatility
If the current IEEE 802.11ad-2012 grant frame field definitions are used, then the system maintains compatibility with existing standards, but the system cannot efficiently indicate the start time of allocated time for rescheduling remainder of TxOP or SP
Solution Approach 1:
The patent redefines the interpretation of the Duration field in the grant frame. Instead of indicating the end of the current TxOP/SP as per IEEE 802.11ad-2012, the Duration field is made to indicate the start time of the allocated transmission opportunity. This parameter redefinition enables clear indication of allocation start time while maintaining the same field structure, thus resolving the information loss problem without adding new fields.
Solution Approach 2:
The grant frame structure is designed to serve multiple functions: it can indicate both the start time and duration of allocated time periods, and it can be used for both new allocations and rescheduling of remainder TxOP/SP. The Duration field serves dual purposes depending on the context, providing versatility while maintaining compatibility with existing frame structures.
2Loss of information
If new fields are added to the grant frame to indicate allocation start time, then the information completeness is improved, but the frame structure complexity increases
Solution Approach 1:
Rather than adding new fields to the grant frame, the patent changes the interpretation/meaning of the existing Duration field. This parameter redefinition approach provides the needed allocation start time indication without increasing the frame structure complexity, as no additional bits or fields are required.
Solution Approach 2:
The existing Duration field in the grant frame structure serves the additional function of indicating allocation start time. The field essentially redefines itself to provide the needed information, eliminating the need for separate indication mechanisms and thus avoiding increased complexity.
3Reliability
If the Duration field indicates the end of current TxOP/SP as per IEEE 802.11ad-2012, then backward compatibility is maintained, but the ability to clearly define allocation start time is lost
Solution Approach 1:
The patent changes the parameter meaning of the Duration field from indicating 'end of current TxOP/SP' to indicating 'start time of allocated time'. This parameter transformation maintains the field's position and format (preserving compatibility) while fundamentally changing its semantic meaning to provide the needed allocation start time information.
Solution Approach 2:
Instead of having the Duration field indicate the end time as per the original standard, the patent inverts the indication to show the start time. This inversion provides the critical missing information about when the allocated time begins, while the field itself remains in the same position within the frame structure.
Data Source
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AI summary
Some demonstrative embodiments include apparatuses, devices, systems and methods of dynamically scheduling a transmit opportunity. For example, a first wireless station may be configured to generate a grant frame including a duration field and a dynamic allocation information field, the dynamic allocation information field including an allocation duration subfield, the allocation duration subfield being set to a value within a predefined range of values, when the grant frame is to grant to a second wireless station a period after a Transmit Opportunity (TxOP), the allocation duration subfield being set to a predefined value which is not within the predefined range of values, when the grant frame is to grant to the second wireless station a period within the TxOP; and transmit the grant frame during the TxOP.