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Re: [STDS-802-16] UL parameter acquisition

Title:
And this does not specify that it is transmitted when it alters, rather when it is needed.  The DLFP can contain the descriptions of up to 4 bursts, so there is no need to use a DL-MAP if the frame contains fewer bursts.  Therefore the downlink transmissions will frequently NOT contain a DL-MAP (at least in lightly loaded systems, or ones with only a few burst profiles defined), though will, with probability close to 1, contain a UL-MAP.

From: Peretz Feder [mailto:pfeder@LUCENT.COM]
Sent: 13 September 2006 18:54
To: STDS-802-16@listserv.ieee.org
Subject: Re: [STDS-802-16] UL parameter acquisition

David:

802.16-2004:

"A DL-MAP message, if transmitted in the current frame, shall be the first MAC PDU in the burst following the FCH. An UL-MAP message shall immediately follow either the DL-MAP (if one is transmitted) or the DLFP."

On 9/13/2006 4:53 AM, David Castelow wrote:
Peretz, Vasanth,
 
I think you may both be confused: Peretz, it would be useful if you could quote the section from where you derive the idea that the maps are only sent when they alter.  This is not the case (IMHO).
The DL-MAP may or may not be sent in every frame per the standard above.  I do agree with you that practically speaking (IMHO as well) DL-MAP and of course UL-MAP should be sent in each and every frame.  
 
In the OFDM PHY (section 8.3) the UL-MAP is sent in every frame, even if it were empty: note the wording in 8.3.5.1: it "shall immediately follow".  (not that I expect it would be empty very often, as in a quiet network you will still require IR opportunities).  The DL-MAP is not necessarily sent every frame, because the DLFP can contain the descriptions of up to the first 4 bursts in the frame, but the DL-MAP also provides additional information that is needed for synchronisation, so must be sent occasionally (more often than the Lost DL-MAP interval, otherwise the SS will sign off: again see 8.3.5.1).  This is the reason that the DL-MAP is not always sent.
 
There are no sign-in problems for 802.16 equipment: interoperable systems are already working.
 
Regards
 
David

Dr David Castelow               Airspan Communications Ltd
Principal Systems Engineer      Cambridge House, Oxford Road
DSP & Systems Design            Uxbridge UB8 1UN, UK
http://www.airspan.com          +44 1895 467281


From: Vasanth.Rajan [mailto:vasantha.rajan@CRANESSOFTWARE.COM]
Sent: 13 September 2006 06:12
To: STDS-802-16@listserv.ieee.org
Subject: Re: [STDS-802-16] UL parameter acquisition

Hi Feder,
 
Thanks for your reply......
 
According to my understanding
 
for e.g. if I select a MAC frame  duration of 10ms, the BS station will send DL-MAP & UL MAP in every  DL subframe (provided the if the MAP messages changes)if I went wrong plz note me...
 
UL_MAP:
But,when the BS is initialized and if there are no SS to receive the MAP messages, in DL subframe period(i.e for every 10 ms completes) the BS has to transmit UL map b'coz the BS has to provide initial ranging period in UL MAP message so that If any SS receives the MAP messages will contend & send the RNG-REQ frame & also the BS will not know when new SS will enter the NW.
DL-MAP:
And let's assume the DL MAP messages are never changed so the BS will never send the DL-MAP and if any new SS station wants to enter the NW then it cant be synchronized with the DL channel unless it receives DLMAP msg???
 
Sorry for a long mail....If I went wrong plz correct me
 
Vasanth
----- Original Message -----
From: Peretz Feder
To: Peretz Feder
Cc: Vasanth.Rajan ; STDS-802-16@listserv.ieee.org
Sent: Wednesday, September 13, 2006 1:10 AM
Subject: Re: [STDS-802-16] UL parameter acquisition

Actually DL-MAP, UL-MAP shall be sent whenever the maps are changed.(See 8.3.5.1)

On 9/12/2006 1:43 PM, Peretz Feder wrote:


On 9/12/2006 2:50 AM, Vasanth.Rajan wrote:

Hi all,

I have some doubt in Scanning & UL parameter acquisition

When the BS is initialized it will send first DL-MAP frame; my question is following the DL-MAP should the BS send UL-MAP frame before transmitting DCD & UCD frames????

DL/UL-MAP goes in every frame to inform and schedule SS(s).
DCD & UCD are sent every (configurable) amount of frames.

In STD 802.16-2004,6.3.9.4 Table 114,Message flow during scanning & UL parameter acquisition process,

Its given that once the SS achives DL syncronization & obtains the UL channel information and then the BS transmits UL-MAP message...How come the BS know that a particular SS has Syncronized with DL & obtained UL channel parameters????so that it could transmit UL-MAP frame.

REG-REQ MAC message

Thanks & reg

Vasanth