Re: [STDS-802-16] DLFP and HFDD
Barra,
Here is a quote from the new draft (D5), page 513, line 32 (OFDM DL_MAP
IE format section)
"Connection Identifier (CID)
Represents the assignment of the IE to a broadcast, multicast or unicast
address.
If the broadcast or multicast CID is used then it is possible to
concatenate unicast MAC PDUs (with different CIDs) into a single DL
burst. During a broadcast or multicast DL burst it is the responsibility
of the BS to ensure that any MAC PDUs sent to an HFDD SS do not overlap
(in time; taking TTG and RTG into account) any UL allocations for that
SS. An HFDD SS for which a DL MAP IE and UL MAP IE overlap in time shall
use the UL allocation and discard DL traffic during the overlapping
period. "
The description is general about time period and not just about PDUs --
correction to my previous note.
Following the SS UL transmission period, if the SS has the ability to
synchronize to the next burst (may be possible in the OFDM/OFDMA PHYs,
with the fact the DL MAP is known to the SS), then he can continue to
receive DL data (randomizer is initialized for every burst). Therefore I
don't believe that the situation is bad as described in Raja's mail.
As a general approach, I believe we should keep any details about
scheduler implementation out of the scope of our standard; therefore the
above language about scheduler behavior is enough.
Regards,
Itzik.
-----Original Message-----
From: owner-stds-802-16@LISTSERV.IEEE.ORG
[mailto:owner-stds-802-16@LISTSERV.IEEE.ORG] On Behalf Of Al Dabagh,
Baraa
Sent: Saturday, May 15, 2004 12:20 AM
To: STDS-802-16@LISTSERV.IEEE.ORG
Subject: Re: [STDS-802-16] DLFP and HFDD
Itzik,
I understand that there need not be any PDU overlap, but how about
bursts overlap? The SS can have a PDU in a DL broadcast burst that is
not overlapping (the PDU that is) with an UL burst but the UL and DL
burst are.
|<------------------ Broadcast DL BURST ------------------>|
|<--- DL PDU for SS0 --->|<----- No DL data for SS0 ------>|
|<- UL Burst for SS0 ->|
Of course the gap between the DL PDU and the uplink burst have to meet
the SS's capabilities.
There is no clear text (that I have seen) that prohibts the above
condition (in HFDD) yet it imposes an interoperability concern, unless
this was the intention.
Baraa Al-Dabagh
BWD
Intel Corporation
baraa.al.dabagh@intel.com
Phone: 408-545-6078
> -----Original Message-----
> From: owner-stds-802-16@LISTSERV.IEEE.ORG [mailto:owner-stds-802-
> 16@LISTSERV.IEEE.ORG] On Behalf Of Itzik Kitroser
> Sent: Friday, May 14, 2004 8:53 AM
> To: STDS-802-16@LISTSERV.IEEE.ORG
> Subject: Re: [STDS-802-16] DLFP and HFDD
>
> Baraa,
>
> If I remember correctly (and now all the details of standard are a big
> mess in my head), then we had a comment that clarified this issue.
> Anyway, the BS should avoid giving UL allocations to a specific SS,
> which overlaps with DL PDUs to same SS.
> Therefore, an SS receiving an UL allocation may assume that there is
no
> awaiting DL PDU during the same time period.
>
> Regards,
> Itzik.
> -----Original Message-----
> From: owner-stds-802-16@listserv.ieee.org
> [mailto:owner-stds-802-16@listserv.ieee.org] On Behalf Of Al Dabagh,
> Baraa
> Sent: Friday, May 14, 2004 4:39 PM
> To: STDS-802-16@listserv.ieee.org
> Subject: [STDS-802-16] DLFP and HFDD
>
> Folks,
>
> I have a question regarding the DLFP and DL/UL allocations (OFDM
256)
> in an HFDD based system:
>
> It seems to be possible that an UL allocation can be in conflict with
> one of the DL allocation specified in the FCH (or the DLFP0 for a
> particular SS. In the case were there is a conflict, should the SS
> assume that there is no allocation for it in the DL burst specified by
> the FCH (or the DLFP) and attempt not to decode it, or should the MAC
on
> the BS be smart enough to allocate on a per PDU level (rather than a
> burst level)?
>
> If the answer is the second option, then this assumes the SS will
decode
> a DL burst, extract the PDUs that belong to it from the burst, and if
> there is an allocation on the UL overlapping then it should terminate
> the DL burst decoding, and start transmitting data!! The same thing
> applies for a broadcast or multicast CID specified in the DL MAP that
> overlaps with an UL allocation.
>
> Thanks
>
> Baraa Al-Dabagh
> BWD
> Intel Corporation
> baraa.al.dabagh@intel.com
> Phone: 408-545-6078