Notification of SFH Updating (16.2.3.14)

advertisement
Notification of SFH Updating (16.2.3.14)
Document Number: IEEE C80216m-09/2907
Date Submitted: 2009-12-31
Source:
Yih-Shen Chen, Kelvin Chou and Paul Cheng
MediaTek Inc.
E-mail: yihshen.chen@mediatek.com, kelvin.chou@mediatek.com
Re: IEEE 802.16-09/0073, “IEEE 802.16 Working Group Letter Ballot#30b”
Base Contribution: This is base contribution
Purpose: Propose to be discussed and adopted by TGm for the 802.16m Amendment
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 >.
Introduction
• To sustain normal network operations, serving ABS broadcasts and
adjusts its configuration via system information updating
– The critical information is broadcasted via P-SFH/S-SFH IEs in 802.16m
• To perform handover, serving ABS allocates a time interval for cell
scanning
– AMS scans the neighboring cells during unavailable time intervals
– AMS resumes the normal data transmission during available time
intervals
• For sleep mode control, the timing of sleep mode control is
– Frame-based operation as baseline
– Subframe-based operation is also supported if configured (16.2.16.2.1)
• E.g., VoIP
– Note that, the timing of SFH broadcasting is superframe-based
operation
2
Problem Description (1/2)
• (Problem #1): What if the system information is
required to be updated while AMS is in the
unavailable interval?
– AMS may not get the up-to-date system information
• ex: BR information, FFR information
• To solve the problem, section 15.2.3.13 of D2
states that:
– …. If Scan Duration field contains a non-zero value, the
system parameters which are carried through SFH shall
not be changed during whole scanning duration specified
in the AAI_SCN-RSP message. ….
3
Problem Description (2/2)
• However, the problem is
– less flexibility of system information updating
• It’s hard to know when AMS requests for scanning in
advance
• It’s not a reasonable design to postpone the SFH updating
just because an AMS is performing scanning operation!
– System information updating is related to cell-wide/networkwide configuration
• (Problem #2): What if AMS wakes up in the
middle of SFH transmission interval?
– The time units of SFH and SLP operation are different
• AMS can wake up earlier to decode SFH and go back to
micro-sleep for power saving
– But, it wastes power anyway
4
Proposed Solution
• BS broadcasts an indication message (e.g.,
AAI_SFH_IND) to announce that system information
updating will happen soon
– The behavior is similar to dynamically broadcast P-SFH to
announce the updating information
• Once an AMS decodes the message, it figures out that
system information is going to be updated
– For AMS under scanning operation:
• It can get the indication message during available time interval
• It finds time to read the SFH updating
– It can use some unavailable interval or available interval to decode SFH
information
» SFH appears periodically!
– For AMS under sleep mode operation:
• It can keep waking up to decode SFH
5
Unavailable
interval
AAI_SFH_IND
Data
communication
SCN-RSP
SCN-REQ
Example of the Proposed Method
Available
interval
Time window for
SFH reading
6
Conclusion
• SFH content update contains two steps:
– Notification of SFH update
– Update mechanism of SFH content
• In this contribution, we propose a method for
notifying SFH update
– It can further enhance the performance of power
saving, especially for subframe-based VoIP
applictions
7
Proposed Text (1/2)
• Modify the text in 16.2.3.14
16.2.3.14 AAI_SCN-RSP
An AAI_SCN-RSP message shall be transmitted by the ABS either
unsolicited or in response to an AAI_SCN-REQ message sent by an AMS.
An ABS may transmit AAI_SCN-RSP to start AMS scan reporting with or
without scanning allocation. If Scan Duration field contains a non-zero
value, the system parameters which are carried through SFH shall not be
changed during whole scanning duration specified in the AAI_SCN-RSP
message. If Scan Duration field contains a non-zero value, scanning interval
pattern which includes the AAI_SCN-RSP message replaces previous
existing scanning interval pattern.
8
Proposed Text (2/2)
• Add a new section 16.2.2.2.10
16.2.2.2.10 SFH Update Extended Header (SUEH)
ABS transmit SUEH to indicate that SFH is going to be updated. When detecting
the message, AMS shall try to obtain the up-to-date SFH information, according to
SFH update operation defined in section X.X.X.X.
Size (bits)
Notes
Type
4
SUEH
SFH version
4
SFH version number
SFH update bitmap
3
Syntax
SUEH(){
Each bit represent the update of
S-SFH IEi, i=1~3, from LSB to
MSB.
Reserved
Variable
For Byte alignment
}
9
Download