Multi-Radio Coexistence: Co-Located Coexistence Class
Document Number: IEEE C80216m-09/559
Voice: +1-503-2647073
Date Submitted: 2009-02-24
Email: jing.z.zhu@intel.com
Source:
Jing Zhu, Aran Bergman, jing.z.zhu@intel.com
Intel Corporation
Re: 8.x IEEE 802.16m Air-Interface Protocol Structure: Multi-Radio Coexistence
Base Contribution: N/A
Purpose: to be discussed and adopted by TGm AWD
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 >.
1
Outline
• Co-Located Coexistence Class
– overview
– BS scheduling behavior
– improvements over Rev2
• Proposed AWD Outline
• Back Up
– co-ex usage scenarios
2
Co-Located Coexistence (CLC) Class: Overview
• Fundamental
– separate 802.16m and non-802.16m activities in time domain
(enhancing the Rev2 co-ex feature: PSC-based CLC)
• Definition
– AMS conducts pre-negotiated periodic absences from the serving
ABS, and the time pattern of such periodic absence is referred by
ABS and AMS as Co-Located Coexistence (CLC) class.
• Requirement
– mandatory for ABS, optional for AMS
• Parameter
– active interval / ratio / period, starting time, number of active classes
• Signaling
– capability notification: CLC Limits TLV (REG-RSP)
– activation / deactivation: MOB_CLC-REQ / MOB_CLC-RSP
3
Comparison of CLC Classes
Type I
Type II
Type III
Targeted non-16m radio
activities
Bluetooth eSCO, Bluetooth ACL,
Wi-Fi beacon, … Wi-Fi data, …
Bluetooth
page/inquiry, WiFi passive scan,
…
Unit of Active Interval
subframe
subframe
second*
Unit of Active Ratio
%
%
%
Unit of Active Period
microsecond
frame
second
Unit of Starting Time
subframe
subframe
frame
Owner of Starting Time
AMS
ABS
ABS
*: 1 second = 200 frames
4
BS scheduling behavior
•
•
•
•
•
CLC Limits
Latency Limit
MAP and HARQ timing
Synchronous Allocation
SFH, Scan, Sleep, Idle, and HO
5
CLC Limits
k-th active
interval
k+1-th active
interval
CLC active interval
CLC active interval
CLC active ratio =
CLC active period
CLC active period
CLC Limits
Maximum Number of
Active Classes of the Type
Maximum Active
Ratio
Maximum Active Interval
Type I
> or = 1
> or = 5%
> or = 5ms
Type II
> or = 1
> or = 30%
> or = 40ms
Type III
1
1%
3 second
–
–
BS shall accept a new CLC class request, and honor it (i.e. not unsolicited deactivate it after
activation) if the CLC class meets the CLC Limits, and may reject it otherwise
CLC limits shall be configured according to the above table to ensure the basic support for
multi-radio co-ex
6
Latency Limit
• The Maximum Latency parameter of an active service flow shall be
guaranteed even if a CLC class is active
– Maximum Latency: the maximum interval between the entry of a packet at the
CS and the forwarding of the SDU to its Air Interface.
• Latency Limit (s): the minimum value of the Maximum Latency
parameters of all active service flows of the AMS
– Latency Margin (d) provides additional time for meeting Maximum latency
requirement (d= 10ms)
CLC Active
MAP Data ACK
Interval (t)
DL
UL
d+t  s
7
MAP and HARQ timing
• ABS shall not schedule an allocation, if Assignment IE (MAP), Data,
or/and ACK of the allocation overlaps with an CLC active interval,
DDL-MAP
FDD
DL
UL
DACK
DACK
CLC active interval
DACK
DDL-MAP
TDD
DACK
CLC inactive interval w/o 16m data
•DACK = 4 and DDL-MAP = 1 (or 0)
•UL MAP relevance not considered
8
Synchronous Allocation
Data
Nack
Data
Nack
Data
Overlap with CLC
active interval
Nack
Data
Ack
Dynamic
Rescheduling
Static
Rescheduling
(with the same
subframe index)
•
•
ABS and AMS shall cancel a synchronous allocation locally if its data or/and ACK
overlaps with an CLC active interval that is no longer than a frame, and reschedule it
after the end of the CLC active interval.
How to indicate the rescheduled allocation?
–
Option 1: dynamic rescheduling (new Assignment IE)
•
–
Pro: lower latency ; Con: control overhead
Option 2: static rescheduling (next available subframe)
•
Pro: no control overhead; Con: higher latency (with the same subframe index)
9
SFH, Scan, Sleep, HO, and Idle
• Super Frame Header
– super frame header may overlap with CLC active interval
• AMS / ABS should set the starting time of a CLC class to avoid SFH
as much as possible.
• Scan Mode
– scan interval may overlap with CLC active interval
• AMS locally decides whether to perform co-ex or .16m scan
• Sleep Mode
– unavailable interval may overlap with CLC active interval
• AMS may use it as additional duty cycle for co-ex
• Handover
– locally suspend all active CLC classes before HO starts, and
resume them after HO completes
• Idle Mode
– locally deactivate all active CLC classes after entering idle mode
10
Improvements over Rev2
•
Efficiency
–
granularity is fixed to frame, e.g. 5ms, and has a direct impact on the efficiency of TDMbased CLC operation, particularly when radio transmissions take less than 5ms
solution: reduce granularity to subframe (617us)
•
Flexibility
–
MS determines CLC pattern, giving little flexibility for BS to adjust according to network
condition
solution: allow BS to determine the starting time
– CLC period has to be the integer number of frames, and may not suitable to some
application.
solution: use microsecond as the unit for period
•
Manageability
– BS has no way to manage the impact of TDM operation on WiMAX performance
solution: CLC limits
•
Scalability
–
only one PSC is allowed active at any given time per MS, and difficult to support multiple
radios / applications.
solution: allow multiple classes and multiple types
•
Compatibility
–
power save needs to be disabled when CLC is active
•
•
sleeping pattern is determined by 802.16m traffic
CLC pattern is determined by co-located non 802.16m traffic
solution: CLC class operation independent of sleep mode
11
Proposed AWD Outline for Multi-Radio Coexistence
15.2.x Multi-Radio Coexistence
15.2.x.1 Co-Located Coexistence Class
12
Back Up
13
Co-Ex Usage Examples
• Bluetooth headset
– eSCO
– page/inquiry
• Wi-Fi
–
–
–
–
–
Beacon Listening
Active Scan
Wireless Peripheral
Wireless P2P
Wi-Fi/WiMAX HO
14
Bluetooth: eSCO + 16m TDD
Max BT Retries = 0, CLC Active Ratio = 17%
Bluetooth Slot
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
.16m subframe
1
2
3
Max BT Retries = 1, CLC Active Ratio = 9%
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
Max BT Retries = 2, CLC Active Ratio = 5%
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
6
1
2
3
4
5
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
1
2
3
4
5
6
7
8
15
Bluetooth: Page / Inquiry
• Bluetooth Page/Inquiry
– Transmit in one Bluetooth slot every 2 slots for at least 2.56
seconds
• each slot is 625 us
 supported by Type III CLC class
(CLC active interval > 2.56s)
• Bluetooth Page/Inquiry Scan
– Listen for 11.25ms (scan window) for every 1.28 seconds
 supported by Type II CLC class
(CLC active ratio = 1 superframe / 64 =1.6%)
16
Wi-Fi: Beacon Listening
.16m subframe
Frame n
n+1
n+20
n+21
……
Wi-Fi
Wi-Fi Beacon
Wi-Fi Beacon
7 subframes (~5ms)
102.4ms
•CLC Active Interval: 5ms
•Beacon transmission time < 5ms
•CLC Active Period: 102.4ms
•Beacon Interval = 102.4ms
•CLC Active Ratio: < 5%
17
Wi-Fi: Active Scan
100ms*
70ms (.16m)
30ms (Wi-Fi)
STA Prob-Req
70ms (.16m)
30ms
ACK
Prob-RSP
AP
Wi-Fi active scan
•CLC Active Interval: 30ms
•Wi-Fi STA usually needs ~30ms to complete one active scan operation
*: other configurations are possible
18
Wi-Fi: (Low-Latency) Wireless Peripheral
•CLC Active Interval: 2 subframes
•CLC Active Period: 5ms
•CLC Active Ratio: 25%
DL: UL
CLC Active Pattern*
6: 2
 .16m data allocation time
 50%
Available Time Ratio for .16m Data Allocations
DL
UL
67%
100%
Unavailable due
to HARQ timing
5: 3
60%
67%
4: 4
50%
50%
3: 5
67%
60%
2: 6
100%
67%
*: only example, and other configurations possible
19
Wireless Peripheral (cont’d)
General
Mouse
Wireless
Keyboard
Voice
Quality
Headset
CD Quality
headphones
Throughput Req.
8kbps
8kbps
256 kbps
384kbps
Latency Req.
< 10ms
< 50ms
< 30ms
< 100ms
Period
10ms
20ms
20ms
20ms
Bytes per period
< 10
<20
640
960
Tx Time*
(11g-only, 6Mbps)
189us
201us
1029us
1453us
x 2 (+ 1 re-transmission)
378us
402us
2058
2906us
CLC Active Interval
(subframes)
1
(0.6ms)
1
(0.6ms)
4
(2.4ms)
5
(3.0ms)
CLC Active period
(frames)
2
4
4
4
CLC Active Ratio
7%
4%
13%
16%
*: no contention from other Wi-Fi STAs;
< 30%
20
Traffic Load of Wireless P2P (Peer-to-Peer)
Usages
Usages
Voice
Projection
File
Sharing
Wireless Display SyncGo
480p
0.1
6
16
17
67
65 (1x2, 20Mhz)
<1%
17%
44%
47%
N/A
135 (1x2, 40Mhz)
<1%
8%
22%
23%
89%
195 (3x3, 20Mhz)
<1%
6%
15%
16%
62%
405 (3x3, 40Mhz)
<1%
3%
8%
8%
30%
Throughput Req. (Mbps)
Maximum
802.11n PHY
Rate (Mbps)
Latency Req. for the above applications: > 10ms
< 30%
Maximum Throughput = PHY Rate x (1 – PER* ) x MAC Efficiency*
Traffic Load = Throughput Req. / Maximum Throughput
*: MAC Efficiency = 80% and PER = 30%, only example, other values possible
21
How will 16m co-ex benefit Wi-Fi / WiMAX HO?
• WiMAX to Wi-Fi
– protecting Beacon
after Wi-Fi STA is
associated with WiFi AP while WiMAX
MS is still
transmitting data
16m Co-Ex starts
here
Rev2 Co-Ex starts
here
• WiFi to WiMAX
– start co-ex operation
right after Basic
Capability
Negotiation to avoid
long authentication
delay
Authentication may take long, and data
transmission over Wi-Fi needs to be protected
22