Comments on SFH IE to Support Network Entry for Multi-Carrier MS
Document Number: IEEE C802.16m-09/0563
Date Submitted: 2009/03/02
Source:
I-Kang Fu, Yih-Shen Chen, Kelvin Chou, Pei-Kai Liao, Paul Cheng
MediaTek Inc.
Email: IK.Fu@mediatek.com
Venue: IEEE 802.16 Session#58 at Vancouver, Canada.
Base Contributions: This is base contribution
Re: IEEE 802.16m-09/0012, “Call for Contributions on Project 802.16m Amendment Working Document (AWD) Content,”
- Comments on P802.16m AWD
Purpose: For TGm member discussion and adoption
Notice:
This document does not represent the agreed views of the IEEE 802.16 Working Group or any of its subgroups. It represents only the views of the participants listed in
the “Source(s)” field above. It is offered as a basis for discussion. It is not binding on the contributor(s), who reserve(s) the right to add, amend or withdraw material
contained herein.
Release:
The contributor grants a free, irrevocable license to the IEEE to incorporate material contained in this contribution, and any modifications thereof, in the creation of an
IEEE Standards publication; to copyright in the IEEE’s name any IEEE Standards publication even though it may include portions of this contribution; and at the IEEE’s
sole discretion to permit others to reproduce in whole or in part the resulting IEEE Standards publication. The contributor also acknowledges and accepts that this
contribution may be made public by IEEE 802.16.
Patent Policy:
The contributor is familiar with the IEEE-SA Patent Policy and Procedures:
<http://standards.ieee.org/guides/bylaws/sect6-7.html#6> and <http://standards.ieee.org/guides/opman/sect6.html#6.3>.
Further information is located at <http://standards.ieee.org/board/pat/pat-material.html> and <http://standards.ieee.org/board/pat >.
General Network Entry Procedure for Multi-Carrier MS
• General network entry / initialization procedure for multi-carrier MS
based on SDD 19.4.3
General ideas:
1.
2.
3.
4.
5.
Common Procedure for
Single-/Multi-Carrier MSs
Scan for DL
available carriers
Multi-Carrier MS follow a
common network entry procedure
as the single-carrier MS
Multi-Carrier BS broadcast the cell
bar bit in each carrier the same as
single carrier mode
Multi-Carrier MS select the
candidate primary carrier based on
cell bar bit
MS and BS exchange their multicarrier capabilities during network
entry
Perform DL Sync. & Ranging
again right after completing the
common network entry procedure
Extended Procedure for
Multi-Carrier MSs
DL Sync. with a
candidate carrier
established
No
Allow Network Entry in
candidate carrier?
Establish
provisioned
connections
BS assigned
carrier > 1?
No
Yes
Yes
Obtain the UL
parameters of the
primary carrier
Ranging in the
primary carrier
BS inform PHY
parameters of
assigned carriers
DL Sync. &
Ranging
Negotiate basic and
multi-carrier
capabilities
Operational
An example to explain general idea (for information)
Discussion Issue#1
• When initialization, multi-carrier MS may randomly select one of the fully
configured carriers as its candidate primary carrier. It can save much
overhead if BS can broadcast which carrier is allowed for network entry.
–
–
–
–
The basic motivation is for load balancing and prevent unnecessary carrier change
This can largely speed up MS scanning and network access
Current IEEE 802.16 Rev2 standard already broadcasts 8 bits load information
Suggest 802.16m AWD include single bit indication in SFH for the same purpose
BS does not broadcast carrier load information
Carrier #4
Network entry...
Carrier #3
Carrier #2
Carrier #1
BS broadcasts the carrier load information
Carrier #4
Multi-Carrier BS
MS3
Carrier #3
Carrier #2
Carrier #1
MS4 MS5
MS2
Multi-Carrier BS
Multi-Carrier MS
MS1
MS1 MS2 MS3 MS4 MS5
Multi-Carrier MS
Discussion Issue#2
After common network entry procedure completed through primary carrier,
multi-carrier MS has to performance DL sync & Ranging again before enabling
multi-carrier transmission.
1. Consider the example as shown in following, where the multi-carrier MS can
support 2 carriers and multi-carrier BS can support 4 carriers.
–
When initial scanning, MS need to scan for the DL A-Preamble transmitted from BS
by adjusting the center frequency of its receiver.
Multi-Carrier BS
Hardware
Controller
Multi-Carrier MS
PHY1
Multiplexer
RF1
RF1
PHY3
PHY2
PHY3
Multi-Carrier BS
Multi-Carrier BS support 4
carriers across 40MHz radio BW
Common MAC
PHY2
Hardware
Controller
Multiplexer
Common MAC
•
40MHz (4096FFT)
PHY4
Frequency
Carrier#1
20MHz (2048FFT)
Multi-Carrier MS
Carrier#2
Carrier#3
Carrier#4
Multi-Carrier MS support up to 2
carriers across 20MHz radio BW. But
it only use 10MHz (or less) for initial
scanning on A-Preamble.
Frequency
Discussion Issue#2
2.
After the symbol detection and fully configured carrier confirmation, the multicarrier MS may then perform network entry through that carrier.
–
The center frequency of multi-carrier MS receiver will be the same as the
primary carrier because of the time domain symbol detection operation
Multi-Carrier BS
40MHz (4096FFT)
Frequency
Primary Carrier
Carrier#1
20MHz (2048FFT)
Multi-Carrier MS
Carrier#2
Carrier#3
Carrier#4
Multi-Carrier MS will adjust its center frequency
be the same as the one of primary carrier when
the A-Preamble is detected. Then multi-carrier
Frequency
MS will complete the common network entry
procedure by signaling and messaging through
this carrier.
Discussion Issue#2
3.
After completing the common network entry procedure, the multi-carrier MS have to
perform DL sync. & Ranging again before activating secondary carrier.
–
Because the center frequency of multi-carrier MS transceiver need to be adjusted again so that
its BW can cover the radio signals transmitted through both carrier#1 and #2.
– After completing the common entry procedure, the MS transceiver BS only cover part of the
carrier#2.
–
It is recommended to do this DL sync. & Ranging right after the common network entry
procedure (e.g. after determining the assigned carrier).
– Otherwise the MS will need to do this adjustment before activating the assigned carrier and will
then disturb the ongoing data transmission in primary carrier. This is really unnecessary.
Multi-Carrier BS
Frequency
40MHz (4096FFT)
Frequency
Primary Carrier
Carrier#1
Carrier#2
Before activating
secondary carrier
transmission
Carrier#3
Carrier#4
Secondary Carrier
Multi-Carrier MS
Right after
completing common
network entry
procedure
Center Frequency
Frequency
Summary
1.
P802.16m AWD needs to define a common network entry procedure
for all MS and an extended procedure only for multi-carrier MS
–
2.
P802.16m AWD needs to keep single bit indication in SFH of each
carrier to help network entry
–
–
–
3.
Based on current idea agreed in SDD (19.4.3)
Align with the idea in current Rev2 standard design
Single bit will be enough
Multi-Carrier should select its primary carrier based on this indication
Network entry procedure in P802.16m AWD needs to allow DL sync.
& Ranging after assigning secondary carriers to MS
–
–
–
Align with SDD (r7) description in line#18, page#150.
Negotiate some time for multi-carrier MS configure its hardware according
to the secondary carriers assigned by BS
This action shall be performed before the end of network entry stage rather
than right before activating secondary carrier
•
Time reservation for hardware reconfiguration will still be necessary. If not, it
will disturb data transmission in primary carrier.
Text Proposal
•
[Add the following text into P802.16m AWD]
15.3.6.5.1.2.2 S-SFH SP1 IE
Table xxx. S-SFH SP1 IE format
Syntax
Size
(bit)
Notes
S-SFH SP1 IE format () {
MSBs of superframe number
TBD
Part of superframe number
S-SFH SP scheduling information
TBD
SP scheduling bitmap
S-SFH SP change bitmap
TBD
1 or multiple bits per SP
Additional broadcast information indicator
TBD
HO information (Open BS/Close BS, UL
load indicator, cell type)
TBD
Cell bar access bit
Reserved
}
1
For uncontrolled HO scenario
0: Allow network entry/reentry
1: MS shall not perform network entry/reentry
through this carrier