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[STDS-802-16] clarification needed on definition of min and max values for Allocation Start Time field.



Hi,

Please go through the following lines and
correct me if my understanding is wrong.

The following sub-section of the std defines the
allocation start time field min and max values:

6.3.7.5.2 WirelessMAN-SCa PHY
TDD, the Allocation Start Time value shall be to the
following limitations:
— Minimum value: Allocation Start Time > Tf
— Maximum value: Allocation Start Time < 2 X Tf

where, Tf  is the beginning of the next frame.

----------------
My understanding:

The Allocation Start Time is related to the UL
sub-frame in TDD operation. The definition of its
value should be w.r.to the start of UL sub-frame in
the current (minimum time relevance) or next frame
(maximum time relevance). 

Hence the min and max values are to be: 

Minimum time relevance:
— Minimum value: Allocation Start Time >= FCH offset 
(UL-MAP may commence immediately after the FCH when
there is downlink data i.e. data DL-MAP IEs)
— Maximum value: Allocation Start Time <  
frame_duration

Maximum time relevance:
— Minimum value: Allocation Start Time >=
frame_duration (UL-MAP starts in the next frame)
— Maximum value: Allocation Start Time < (2 X
frame_duration)

The point is the UL-MAP has to end in the frame in
which its allocation starts, i.e. 
- in miminum time relevance case, the start and end
happens in the current frame and 
- in maximum time relevance case, the start and end
happens in the next frame.

The pictorial representation in earlier version of
standard was to this extent.

Thanks for your time,
-Giridhar.


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