Reply comments on MC DG Handover Section
Document Number: IEEE S802.16m-09/1629
Date Submitted: 2009-07-13
Source:
Youngsoo Yuk, Inuk Jung, Eunjong Lee
Kiseon Ryu and Ronny Kim
E-mail : sixs@lge.com
LG Electronics
Re:
IEEE 802.16m-09/0028 -Call for Contributions on Project 802.16m Amendment Content (draft)
Purpose:
For discussion and adoption in DG reply comment
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Issues
• Multicarrier Configuration
– To be Broadcast or to be Unicast
– MC-ADV or Re-use AAI-NBR-ADV
To be broadcast or to be unicast
•
In DG Draft
– AMS may receive MC configuration via broadcast MSG
– The alternative option which was “ABS may provide MC configuration via unicast MSG
if requested by AMS” was removed.
•
Two cases
– Fortunately, if AMS receives MC-ADV before MC capability negotiation , OK
– Unfortunately, if AMS doesn’t receive MC-ADV during network entry, AMS should wait
until it is received.
•
How frequently does broadcast MC configuration ?
– Short period : Short delay but large overhead
– Long Period : Low overhead but long delay
Super-frame contains MC-ADV (be broadcast)
Region good for unicast
…
…
AMS1 tries to access
AMS2 tries to access
To be wait
Region good for broadcast
To be broadcast or to be unicast
Broadcast
Unicast
Pros
- Provide MSG to multiple AMSs
simultaneously
- Easy to schedule
- Can be re-used for AMSs to be intercarrier HO
-Need not to be wait
- Efficient transmission via AMC and
HARQ transmission
Cons
-Higher overhead due to lowest MCS and
non-HARQ transmission ( more 10 times
overhead than unicast)
- AMS should wait performing carrier
assignment procedure until it is received
- Duplicated transmission for multiple
AMSs
Good
Condition
With large number of AMSs performing
network entry in a transmission period
With small number of AMSs
performing network entry in a
transmission period
•Our Recommendation
• Increase period of broadcast & allow AMSs to request to be unicast
• According to AMSs policy, AMS can choose one of the options
• Broadcast MSG should be re-used by AMSs for inter-frequency handover
MC-ADV or Re-use AAI-NBR-ADV
• Where to be broadcast
– AAI_NBR-ADV or New MSG, MC-ADV
– New MSG was recommended by DG folks.
• Why New MSG? (Reality or Misunderstanding)
– To avoid size extension of AAI-NBR-ADV ?
• Almost same contents for AAI-NBR-ADV and MC-ADV (Slide #6)
• Info for partially configured will be replaced by AAI_EMBS-ADV (TBD)
• MC information may help to optimize the size of AAI-NBR-ADV (Slide #7)
– No effect to SC AMS ?
• SC AMS shall receive MC-ADV to acquire the information related to the
inter-frequency HO
– Long Period of AAI-NBR-ADV ?
• To increase efficiency, the period of MC-ADV should be long enough (Slide
#4)
• Which message is more frequently used?
– MC-ADV : used by AMSs performing network entry and inter-frequency
handover
– AAI-NBR-ADV : used by AMSs performing all kinds of handover and even
network entry
MC-ADV or Re-use AAI-NBR-ADV
• Parameters for MC Configuration and Neighbor Advertisement
– Most of the parameters are common to both MSG (almost same)
– Carrier Type need not to be transmit until it activated or it can be sent as MBS
MSG (and it is just one bit per carrier)
Syntax
Size (bits)
MC
configuration
Neighbor
Advertisement
Information for
SC AMS
Preamble Index
[16]
Yes
Yes
Yes
Physical Carrier Index
Implicit
Yes
Yes (BS ID)
Yes (BS ID)
Center Frequency
[26]
Yes
Yes
Yes
Bandwidth (5, 10, 20 MHz or others) [2]
Yes
Yes
Yes
Carrier Type
1
Yes
No
No
Duplexing Mode
2
Yes
Yes
Yes
Legacy Support
[TBD]
Yes
Yes
Yes
Common MAC Info
[1]
Yes
Yes for MC
Handover
No
Frequency Offset Information
TBD
Yes
Yes
Yes
…
…
Optimized Design of AAI-NBR-ADV by
using multicarrier information
• Multicarrier Configuration Index (MCI)
– Center frequency, Bandwidth, Common MAC Information, Frequency offset Info.
• MCI can help reducing the bits to be included in AAI-NBR-ADV
• Amount of parameters related to MAC/ISP/NSPs can be omitted for multiple
carriers without indication
– Example : 4 x 10MHz carriers with frequency shift
General Method
MCI (Proposed by LG : see Appendix )
Parameters
Size
Parameters
size
Band class Index
10
Band class Index
10
Channel Index (center
frequency: Optimized)
4 * 10 = 40
Channel Index of reference
carrier (center frequency)
10
Number of component carriers
4
Bandwidth
4 * 2 ~3 = 8 or 12
Reference Carrier Index
2
Frequency Offset Info
4*[3~4] = 12~16
Component Carrier Index
2
Configuration Type
1
Total
29
Total
74 ~ 82
Optimized Design of AAI-NBR-ADV by
using multicarrier information
• Example of AAI-NBR-ADV
– All information same as the serving FA or serving BS with a MCI can
be omitted.
Information on Co-located FAs
Information of FAs with same Bandclass as
serving FA
- MCI
- Shared Info for all Fas (Can be omitted)
- Dedicated Info for each FA
Information of FAs with different Bandclass
from serving FA
- Band Class Index
- Center Frequency of Reference Carrier
- Delta of all information among
- MCI
- Shared Info for all FAs
- Dedicated Info for each FA
Information on NBR FAs
Information of FAs with same Bandclass as
serving FA
Delta of all information among
- MCI
- Shared Info for all FAs
- Dedicated Info for each FA
Information of FAs with different Bandclass
from serving FA
- Band Class
- Delta of information
Conclusion
• Same information should be included in both
MC-ADV and AAI-NBR-ADV
• Long period of broadcast with support of
unicast method is helpful to increase the
system efficiency
• MCI-based design of AAI-NBR-ADV reduces
the information overhead
• Recommend to re-use AAI-NBR-ADV to
broadcast MC configuration
Proposed Text
• Adopt proposed text in C80216m-09/1629r1
– Page 6, on MSG fo AAI_NBR-ADV
Appendix
• Multicarrier Configuration Index IE for carrier aggregation
Syntax
Size (bit)
Notes
Multicarrier Configuration Index IE() {
Number of component carriers
[4]
Number of component carriers in a configuration :
Value + 1 carrier(s)
Reference Carrier Index
Variable
(ceiling(log2(Number of
component carrier))
Index of reference carrier aligned to frequency raster
Component Carrier Index
Variable
(ceiling(log2(Number of
component carrier))
Carrier Index for carrier which contains the
information of this information.
Configuration Type
1
0b0 : Homogeneous Aggregation
0b1: BW types are mixed for Aggregation
Variable
(2*Number of component
carriers)
Bitmap except component carrier
0b00 : 5MHz
0b01 : 10MHz
0b10 : 20MHz
0b11 : others (3MHz, 7MHz or 8.75MHz)
If(Configuration Type ==1){
Configuration Bitmap
}
Reserved and Padding
}
[TBD]
Appendix
• Example of bit reduction with MCI (see slide #7)
Configuration
General Method (bits)
MCI-based Method (bits)
Relative Size (%)
{10, 10}
46
27
59
{10,20, 20, 10}
74
37
50
10 x 8
138
31
22
{10, 20, 10, 20, 10, 20}
106
43
41
10 x 8 (If serving FA is
included in the MCI)
105
9
8.6