Extended MAC Header for System Information Update Notification (16.2.2.2)
Document Number: IEEE C80216m-10/0212r3
Date Submitted: 2010-03-16
Source:
Yih-Shen Chen, Kelvin Chou and Paul Cheng
MediaTek Inc.
E-mail: yihshen.chen@mediatek.com, kelvin.chou@mediatek.com
Re: Letter Ballot #31a on the Draft Amendment (IEEE P802.16m/D4)
Base Contribution: This is base contribution
Purpose: Propose to be discussed and adopted by TGm for the 802.16m Amendment
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Introduction (1/3)
• 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
• SFH update mechanism is defined in 16.2.23
– When P-SFH change count is updated, AMS shall decode the up-todate system information according to S-SFH bitmap information
– The minimal validity duration of each S-SFH IE SP is determined by
“Rate of change of S-SFH info” in SP3
• The timing of SFH broadcasting is superframe-based operation
• For sleep mode control, there are two time units:
– Frame-based operation is the default time unit
– Subframe-based operation is also supported if configured (16.2.16.2.1)
• E.g., VoIP
• Obviously, the timings of SFH transmission and and sleep mode
control are different
2
Introduction (2/3)
• In current specification, AMS may wake up a little bit
earlier to get the system information
– Micro-sleep-like mechanism can be applied
• With the knowledge of S-SFH update periodicity, AMS
can wake up some specific SFH time to decode SFH
information
• It is assumed that SFH update rate is very low
– Most of the time, AMS checks P-SFH change count and nothing
happens
• Moreover, S-SCH tracking is good enough to maintain
physical layer synchronization
• Therefore, it is motivated to reduce SFH decoding rate
for sleep-mode operation
3
Introduction (3/3)
• Another question is related to the information
update of broadcast messages:
– AAI_SCD
– AAI_NBR-ADV
• It’s better to have an indication to notify the
system information update for sleep mode AMS
4
Proposed Solution
• ABS transmits a unicasting message to sleep-mode AMS for
notifying the coming of system information update
– It can be a piggyback extended MAC header
• Once the AMS decodes the message, it figures out that system
information is going to be updated
– It can keep awake to decode SFH or broadcasting MAC management
messages
• Performance analysis:
– Pros:
• AMS does not require to decode SFH frequently
• AMS can figure out when broadcast MAC messages will be transmitted
– Cons:
• DL signaling overhead
• Since SFH update does not happen frequently, the overhead is
acceptable
5
Proposed Text (1/1)
• Add the following fields in Table 813 S-SFH SP3
IE format
Syntax
Size (bits)
Notes
AAI_SCD change count
4
The change count of AAI_SCD
AAI_NBR-ADV change
3
The change count of AAI_NBR-ADV
count
}
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