Proposed Text of Device Collaboration Mode for M2M Application
IEEE 802.16 Presentation Submission Template (Rev. 9)
Document Number:
IEEE C802.16p-11/0048
Date Submitted:
2011-03-14
Source:
Jinsoo Choi, Kyujin Park, HanGyu Cho, Kiseon Ryu, Jin Sam Kwak
Email: js.choi@lge.com
LG Electronics
Re:
Comment on IEEE 802.16p PWR RG document C802.16p-rg-11/0002
Abstract:
This contribution provides the proposed text of device collaboration mode for M2M application to be included in IEEE
802.16p amendment document.
Purpose:
To be discussed and adopted in the IEEE 802.16p amendment document.
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:
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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.
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1
Introduction
 IEEE 802.16p PAR scope
•
This amendment specifies IEEE Std 802.16 medium access control (MAC) enhancements
and minimal orthogonal frequency division multiple access (OFDMA) Physical Layer (PHY)
modifications in licensed bands to support lower power consumption at the device,
support by the base station of significantly, efficient support for small burst transmissions,
and improved device authentication.
 For the requirements above, device cooperation is promising for M2M from the
perspective of
•
M2M requirements
 Low power consumption at the device
 Cost-effective M2M device
•
M2M features
 Low or no mobility
 Time tolerant data transmission
 Infrequent small data transmission
•
M2M applications
 Smart Grid
 Sensors (e.g. disaster, climate, flood, trash can, etc.)
 In this proposal, focusing on the first requirement about lower power consumption,
•
•
Device collaboration scheme is suggested for only fixed M2M devices (i.e. M2M devices with
no mobility).
The application scenario of device cooperation is mainly focused on UL case to reduce M2M
device transmit power consumption. The necessity of device cooperation for DL case is FFS.
2
Motivation on M2M device cooperation
 To increase network lifetime by resolving unbalanced power consumption among
fixed M2M devices
•
•
For fixed M2M devices, the energy consumption and relevant battery lifetime of each
M2M device will be different depending on the geometry of the devices even if the
M2M devices are same type of devices (with same battery equipped) which are
deployed by a same user(or service provider). In the case of the battery of cell-edge
M2M devices, it is needed to replace the battery much frequently comparing with the
near-cell M2M devices which is undesirable for M2M users (services providers).
Device cooperation can be a candidate solution for this power unbalancing among
fixed M2M devices deployed by a same user(service provider) through pathloss
reduction gain.
Cooperative device
L1, L3 << L2
L1
L1 : pathloss between near-cell M2M device and BS
L3
L2: pathloss between cell-edge M2M device and BS
Near-cell M2M device
L2
L3: pathloss between near-cell and cell-edge M2M devices
IEEE 802.16p BS
Cell-edge M2M device
Figure1: Cooperative transmission with reduced pathloss
Target source device who requires low power consumption
3
Motivation on M2M device cooperation (cont’d)
 Battery lifetime extension for battery-limited M2M devices
•
•
Device cooperation can be also useful for battery lifetime extension for battery limited
M2M devices. A nearby M2M device with power source can relay the UL transmission
of battery-limited M2M devices which result in path-loss gain and reduced power
consumption for UL transmission of the battery-limited M2M devices.
A group anchor device which may have a power source can also gather the data
traffics of nearby battery limited M2M devices and forward them to the BS. In aspect
of power management by the operator in fixed scenario as well as enabling efficient
group control of multiple M2M devices, this concept could be more feasible to utilize
device cooperation mode in M2M application.
M2M device with power source
X
Anchor device
IEEE 802.16p BS
Figure2: Cooperative transmission through anchor type of device
4
Scenarios for anchor type of cooperative transmission
IEEE 802.16p BS
IEEE 802.16p BS
Dual mode anchor
source
Single mode anchor
source
802.16 link
source
source
802.11 link
Case-1: Cooperative transmission using dual-mode
anchor device
Case-2: Cooperative transmission using single-mode
anchor device
Case-1
Case-2
Technology
Dual-mode equipment
- Source-anchor link is out of scope
in 802.16p
Single-mode equipment
- Low cost
- Power-efficient protocol used in sourceanchor link
- Coverage of anchor
Scenario
Where short range network such as
802.11 link is well equipped (e.g.
urban area)
Where new network link is required to be
settled in wide-range (e.g. rural area or
rarely short range network existed)
5
Design on the device cooperation in 802.16p
 Main design criteria
•
•
The design should be considered based on 802.16p PAR scope and SRD.
The proposed scheme should not change and modify the existing operation/rule.


•
Based on existing frame structure, resource allocation, control signaling, etc
Maintaining the existing HARQ timing rule/equation
There will be no critical performance impact on the other AMSs’ operation.


No critical performance degradation on other AMSs who are not operated by device cooperation
Require transparent operation with other AMSs’ operation
 Proposed device cooperation method
•
First define related terminologies


•
Consider required capability, especially for cooperative M2M device


•
Source M2M device
Cooperative M2M device
Listen to data/control from source M2M device
Send data & control of the source M2M device to the 16p BS
Design operations for cooperation mode



The cooperative M2M device shall stop UL transmission during the interval when listening to the UL
signal from the source M2M device.
The halt interval in the cooperative M2M device may be configured based on the subframe level or
radio frame level. The possible PHY impact on subframe level configuration (e.g. unnecessary
symbol puncturing, long TTI usage restriction, etc), the frame level configuration is recommended.
Focusing the usage of device cooperation mode on M2M devices who really require low power
consumption rather than delay sensitive transmission, possible delay problem would not be critical
issue.
6
Proposed mode switching for cooperative transmission
Frame #N
Frame #(N+1)
802.16p BS
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
Cooperative
device
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
Device state
Off state
On state
D2D listening interval
Source
device
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
Device state
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
DL
SF0(6)
DL/UL data & control
for source device
•
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
Off state
On state
 On state mode
DL
SF1(6)
DL/UL data & control
for cooperative device
Figure3: Example of frame based on/off-state switching
In aspect of source device
Receive the DL data and control from the BS directly in DL subframes, and transmit UL data and control to
the cooperative device in UL subframes.
In aspect of cooperative device
 Receive DL data and control for itself from the BS in DL subframes, and transmit its own UL data and
control to the BS in UL subframes. Additionally, it shall relay the UL data and control of the source device,
received in the D2D listening interval of the previous ‘off-state’ interval, to the BS.

•
 Off state mode
•
•
In aspect of source device
 Conduct as power saving mode.
In aspect of cooperative device
 Shall receive UL data and control from the source device through the UL subframe(s) (i.e. D2D listening
interval). It can be also operated as power saving mode if needed.
7
Consideration on system impact with the proposed scheme
 Frame structure and resource allocation
•
•
•
Existing frame structure can be used for both TDD and FDD cases.
Based on frame-level mode switching, no new subframe type or symbol puncturing is
required.
No separated region to operate device collaboration mode with existing AMSs is
needed.
 HARQ timing rule
•
•
Existing HARQ timing rule based on aligned position of assignment, data burst
transmission and HARQ feedback can be applied.
For M2M devices who are operated in device collaboration mode, frame level latency
can occur according to defined HARQ process and error handling (b/w source and
cooperative or b/w cooperative and BS) method. But, because device collaboration
mode will be applied in the scenario which requires low power consumption rather
than delay sensitive transmission, this impact would not be critical.
 Scheduling
•
Basically it is assumed that both source device and cooperative device receive the
assignment information in their on-duration based on existing assignment method. In
off duration, the cooperative device can receive the assignment information of the
source device or maintain the off-state for power saving.
 Grouping b/w source and cooperative device
•
Considering fixed M2M devices within a same user (service provider), grouping b/w
source and cooperative device can be set as the predefined way to avoid unnecessary
signaling and scheduling overhead.
8
Conclusion
 To support the requirement of low power consumption of M2M devices,
•
•
•
Device cooperation scheme can be a good candidate solution in M2M power-limited
environment.
Considering efficient power management by the operator in fixed scenario as well as
enabling efficient group control of multiple M2M devices, the anchor type of
cooperative transmission could be more feasible way to utilize device cooperation
mode in M2M application.
While maintaining existing frame structure/HARQ timing/resource
allocation/scheduling, we can design the operation of device cooperation mode.
 To mature the design based on the proposed high-level concept, following
consideration can be further studied.
•
•
•
•
The detail DL/UL signal path and device operation during HARQ retransmission procedure
Proper duration and its periodicity of switching mode for cooperative Tx.
Control signaling
Etc.
9
Proposed text
--------------------------------------------------------Start of the text------------------------------------------------------
Adopt the proposed text in “3. Definitions” and “16.2.29 Device collaboration” sections in
802.16p PWR RG document C802.16p-rg-11/0002 as following.
3. Definition
3.x Source M2M device: The end device whom the data traffic to the BS is generated from or the data traffic
generated from the BS is targeting for
3.x Cooperative M2M device: The device who helps the source M2M device(s) in UL by relaying or cotransmitting data and control information
16.2.29 Device collaboration for M2M application
Device collaboration is a technique where a certain device helps the other device’s transmission.
Especially, the device collaboration is supported for lower power consumption of a specific M2M source
device by reducing the UL pathloss and relevant Tx power of the source M2M device. For supporting
device collaboration, the cooperative M2M device shall stop UL transmission during the interval when
listening to the UL signal from the source M2M device.
16.2.29.1 Device collaboration mode
The Device Collaboration mode is configured to support the cooperative M2M device receiving the UL
data & control of the source M2M device and relaying them to the BS.
Once the device
collaboration is triggered, the Device Collaboration mode is configured to both of the source and
cooperative M2M devices.
10
Proposed text (cont’d)
16.2.29.1.2 Frame based on-off switching
During the device collaboration mode, both of the source and cooperative devices operate with
switched manner of two different device states; On-state and off-state. The interval of the ‘on-state’
and ‘off-state’ is identically equal to a frame interval (i.e. 5ms) respectively. The device state of the
source device shall be cross-paired with the device state of the cooperative device, i.e. the ‘on-state’ of
the source device shall be overlapped with the ‘off-state’ of the cooperative device and vice versa. Fig. x
shows the example of the frame based on-off switched operation of the source and cooperative devices
in device collaboration mode.
16.2.29.1.2.1 On-state
During the ‘on-state’ interval, the source device shall receive the DL data and control from the BS
directly in DL subframes, and transmit UL data and control to the cooperative device in UL subframes.
The cooperative device shall also receive DL data and control for itself from the BS in DL subframes,
and transmit its own UL data and control to the BS in UL subframes. And additionally, it shall relay the
UL data and control of the source device, received in the D2D listening interval of the previous ‘offstate’ interval, to the BS.
16.2.29.1.2.2 Off-state
During the ‘off-state’ interval, the source device may conduct as power saving mode. It may not receive
any DL signal from the BS and transmit any UL signal. The cooperative device shall receive UL data and
control from the source device through the UL subframe(s) (i.e. D2D listening interval) in ‘off-state’
interval.
11
Proposed text (cont’d)
Frame #N
Frame #(N+1)
802.16p BS
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
Cooperative
device
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
Device state
Off state
On state
D2D listening interval
Source
device
Device state
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
UL
SF5(6)
UL
SF6(6)
UL
SF7(5)
DL
SF0(6)
DL
SF1(6)
DL
SF2(6)
DL
SF3(6)
DL
SF4(5)
Off state
On state
DL/UL data & control
for source device
DL/UL data & control
for cooperative device
Figure x – Example of source and cooperative device operation during device collaboration mode.
--------------------------------------------------------End of the text-----------------------------------------------------12