Re: [STDS-802-16] scanning..
Hi, Vasanth
I also recommend Vasanth to meditate the chapters in the specification.
The specification is integrated so that a thorough reading from the first
page to the last page can enhance your understanding.
I wonder the following is help:
1. UCD: Uplink channel descriptor to define the characteristics of a
downlink physical channel.
DCD: Downlink channel descriptor to define the characteristics of a
downlink physical channel.
For example, IEs such as "RNG Back off start" in the part of "All channel
encodings" define the uplink access constant when in contention. These IEs
are constant and it is unnecessary to change their value in a long time.
IEs like "Modulation Type" in the area of "Downlink_Burst_Profile" are PHY
specific. These channel description IEs tells SS the processing capablity of
BS of uplink and downlink. To ease the implementation of UE, the
channel access methods are classified into several profiles(These profiles
correspond to the value of DIUC or UIUC).
If you study the IEs of DCD & UCD more times, you will be more clear.
2. DL-MAP: The DL-MAP message allocates access to the downlink channel.
UL-MAP: The UL-MAP message allocates access to the uplink channel.
In order to meet the Qos of a connection, a MAP message should be sent
to adapt to a change of channel. For example, if the RSSI that MS can receive
becomes lower to -100 dBm, the MS may ask a DIUC and UIUC change. In
the case, the MAP message will change and there is no change of DCD and UCD.
In fact, DIUC and UIUC in MAP messages are indices to PHY burst profiles.
Using index instead of burst profile can avoid unnecessary data transfer
between MS and BS.
3. As to the parameters of "RNG Back off start", you had better to check
the algorithm of "truncated binary exponential backoff". I think you may
have a mistake.
----- Original Message -----
From: Itzik Kitroser
To: STDS-802-16@LISTSERV.IEEE.ORG
Sent: Friday, August 18, 2006 7:26 PM
Subject: Re: [STDS-802-16] scanning..
Hi,
I recommend you to re-read the relevant text from the standard.
UCD/DCD and MAP messages are not related.