Transcript IEEE C802.16m-09/0620

Differentiated Random Access Schemes
Document Number: IEEE C802.16m-09/0620
Date Submitted: 2009-03-02
Source:
Heejeong Cho
Kiseon Ryu
Doohyun Sung
Ronny(Yong-Ho) Kim
Jin Sam Kwak
E-mail : [email protected]
LG Electronics
Re:
IEEE 802.16m-09/0012 -Call for Contributions on Project 802.16m Amendment Working Document (AWD) Content, on the topic of
802.16m AWD – Bandwidth Request Procedure (based on the section 10.10 QoS and 11.9 UL Control Structure in SDD)
Purpose: To provide the details of the C802.16m-09/0619 - Proposed Text Related to Bandwidth Request Procedure for the IEEE 802.16m
Amendment
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Outline
• Differentiated Random Access Schemes for
Bandwidth Request
– Differentiated Timer based Random Access Scheme
was proposed in Session #59 (IEEE C80216m09/0293, IEEE C80216m-09/0180r4) and adopted in
the SDD text (IEEE C80216m-09/003r7).
– Acknowledgement based Random Access Scheme
was adopted in the SDD text (IEEE C80216m09/003r7).
• In this contribution, we provide more details for
two schemes.
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Differentiated Random Access
Scheme
•
AMS’s operation phases
–
Phase 1 - To transmit a bandwidth request indicator
•
–
Phase 2 - To wait for UL grant
•
•
•
•
Transmit an access sequence (and quick access message only for 3-step procedure) and go to phase
2
Transmit a BW-REQ message and go to phase 2
Transmit data and finish
Go to phase 1
ABS’s operation phases
–
Phase 1 - To wait for a bandwidth request indicator
•
Transmit UL grant
–
–
•
–
Go to phase 2
Phase 2 - To wait for available resource
•
Transmit UL grant
–
–
•
–
5-step procedure : go to phase 3
3-step procedure : finish
5-step procedure : go to phase 3
3-step procedure : finish
Transmit acknowledgement and go to phase 2 (if ABS supports acknowledgement)
Phase 3 - To wait for BW-REQ message
•
•
•
Transmit UL grant and finish
Go to phase 2
Finish
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AMS’s phase 1 - transmit bandwidth
request indicator (1/2)
• Step 1
– Transmit an access sequence.
– Transmit a quick access message
along with the access sequence for the
optional 3-step quick access procedure.
• Step 2
– Start differentiated timer
according to service type/priority.
• Step 3
Wait for BR opportunity
BR opportunity Information
Send access sequence
(and quick access message)
Start differentiated timer
Wait for UL grant
– Go to phase 2 - wait for UL grant
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AMS’s phase 1 - transmit bandwidth
request indicator (2/2)
• An example of timeout values at step 2
Value
Service type
Priority
Timeout value
00
Delay-sensitive
High
50ms
01
Delay-sensitive
Low
100ms
10
Delay-tolerant
High
150ms
11
Delay-tolerant
Low
200ms
50ms
50 ms
No
grant
t
Grant
100 ms
Time duration
Transmission of BR indicator
No
grant
Time
Grant
Retransmission of BR indicator
t
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AMS’s phase 2 - wait for UL grant (1/3)
• Event 1 - receive UL grant before timeout
– Step 1
• Stop differentiated timer
– Step 2
• Perform step 2-1 or 2-2
– Step 2-1 : Transmit BW-REQ message and go to phase 2
– Step 2-2 : Transmit data and finish this procedure
• Event 2 – timeout of differentiated timer
– Step 1
• Increment retry counter
– Step 2
• Go to phase 1 unless the maximum number of retries has
been reached.
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AMS’s phase 2 - wait for UL grant (2/3)
• Event 3 - receive acknowledgement
– Step 1
• Restart differentiated timer
– Step 2
• Go to phase 2
• Event 4 – not receive acknowledgement
– Step 1
• Stop differentiated timer
– Step 2
• Increment retry counter
– Step 3
• Go to phase 1 unless the maximum number of retries has been
reached.
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AMS’s phase 2 - wait for UL grant (3/3)
Wait for
UL grant
ACK not
received at
the specific
sub-frame
ACK at the
specific
sub-frame
Stop
differentiated
timer
Restart
differentiated
timer
UL grant
Increment
retry counter
Stop
differentiated
timer
No
Yes
Wait for
UL grant
Increment
retry counter
Timeout
differentiated
timer
Yes
Retry
counter
== MAX
For BWREQ
No
Yes
Send
BW-REQ
Retry
counter
== MAX
Yes
Wait for
BR opportunity
No
End
Wait for
BR opportunity
Unsuitable
size
No
Restart
differentiated
timer
Wait for
UL grant
Send data with
additional BR
information
Send
data
End
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ABS’s phase 1 – wait for bandwidth
request indicator (1/2)
• Step 1
– Detect an access sequence
• Step 2
– Perform step 2-1 or 2-2 when the ABS has available resource
• Step 2-1 : allocate UL resource for transmitting BW-REQ message
and go to phase 3
• Step 2-2 : decode a quick access message and
– If decoding success, allocate UL resource for transmitting data and
finish this procedure.
– If decoding failure, allocate UL resource for transmitting BW-REQ
message and go to phase 3.
– Perform step 2-3 when the ABS doesn’t have available resource
• Step 2-3 : go to phase 2
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ABS’s phase 1 – wait for bandwidth
request indicator (2/2)
Wait for
BR indicator
Access sequence
(and quick access
message)
Good enough
for access
sequence
Yes
3-step
procedure
No
No
End
Yes
Yes
Yes
Have
available
resource
Good enough for
quick access
message
No
No
Send UL grant
for data
End
No
Have
available
resource
Yes
Send UL grant
for BW-REQ
Wait for
available resource
Wait for
BW-REQ
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ABS’s phase 2 – wait for available
resource (1/3)
• Event 1 – have available resource
– Step 1
• Perform step 1-1 or 1-2
• Step 1-1 : allocate UL resource for transmitting BW-REQ message
and go to phase 3
• Step 1-2 : allocate UL resource for transmitting data and finish this
procedure.
• Event 2 – have no available resource until frame offset
– Step 1
• Transmit acknowledgement at the specific sub-frame decided by
frame offset
– Step 2
• Go to phase 2
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ABS’s phase 2 – wait for available
resource (2/3)
• If the frame offset where the acknowledgement
will be transmitted is not defined,
– AMS should check whether it was received or not
every frame until the predefined period.
– ABS should send acknowledgement message
including some information such as frame number in
which the access sequence to which this message
responds was transmitted.
• It is necessary to define frame offset between the
bandwidth request indicator or BW-REQ
message and the acknowledgement.
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ABS’s phase 2 – wait for available
resource (3/3)
Wait for
available resource
Resource not exist
until the specific
sub-frame
Available
resource
Yes
No
Send ACK at
the specific sub-frame
For data
Send UL grant
for data
Send UL grant
for BW-REQ
End
Wait for
BW-REQ
Wait for
available resource
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ABS’s phase 3 – waiting for BW-REQ
message (1/2)
• Event 1 – receive BW-REQ
– Step 1
• Decode BW-REQ message
– Step 2
• Perform step 2-1 or 2-2 when the ABS has available resource
– Step 2-1 : If decoding success, allocate UL resource for transmitting
data and finish this procedure.
– Step 2-2 : If decoding failure, finish this procedure
• Perform step 2-3 or 2-4 when the ABS doesn’t have available
resource
– Step 2-3 : If decoding success, go to phase 2
– Step 2-4 : If decoding failure, finish this procedure
• Event 2 – not receive BW-REQ
– Step 1
• Finish this procedure
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ABS’s phase 3 – waiting for BW-REQ
message (2/2)
Wait for
BW-REQ
BW-REQ not
receive at the
allocated resource
BW-REQ
Yes
No
Good enough
Yes
Have available
resource
No
Send UL grant
for data
End
Wait for
available resource
End
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Amendment Text Proposal
Adopt text proposal for the 802.16m amendment in the
contribution IEEE C802.16m-09/0619 or its latest version.
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