Transcript Power Reduction in JTRS Radios with ImpacctPro

Power Reduction in JTRS Radios
with ImpacctPro
Jiwon Hahn, Dexin Li, Qiang Xie,
Pai H. Chou, Nader Bagherzadeh,
David W. Jensen*, Alan C. Tribble*
UC Irvine, EECS
*Rockwell Collins, Inc
MILCOM
November 2, 2004
Joint Tactical Radio System
Embedded in various military platforms
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JTRS
• Software Defined Radio (SDR) Technology
earmarked for all DoD platforms by 2010
• Multi-band, multi-mode digital radio
• Layered open-architecture system
• Provides transmission interoperability
between different networks such as army,
legacy and commercial networks
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Outline
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Motivation and Goal
Methodology
Tool: ImpacctPro
Simulation Results
Conclusion
4
Example JTRS Radio
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JTRS Step 2B designed by Rockwell Collins
Consumes 9.7 MJ for realistic 10 hour mission!
No power management
Airborne radio form factor
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Challenges for Power
Reduction
• Complex Architecture
• 28 Subsystems
• 4 Parallel Channels
• 3 Shared resources
Power
Amplifier
Transceiver
Modem
Black
Processor
Channel 4
(MilStar)
Red
Processor
Red
Power
Power
Amplifier
Transceiver
Modem
Black
Processor
Channel 3
(ATC)
Red
Processor
Red
I/O
Channel 2
(SATCOM)
Red
Processor
• Power consumption levels
Channel 1
Power
Black
Transceiver
Modem
• Amplifier
Number
of power
modes
Processor
(Link 16)
• Mode transition characteristics
Red
Processor
• Diverse Components
• Different power manageability
Power
Amplifier
Transceiver
• Dependencies
Black
I/O
Black
Power
System
Power
Modem
Time Base
/ GPS
Black
Processor
Domain
Controller
Encryption
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Enhancing Power
Management Features
• Development Cost
• Hardware and software modifications
• Extensive testing
• Evaluation
• Not all power modes usable due to system
complexity
• Analogy of Amdahl’s Law
• Need a methodology and tool
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Overview
Tool
(CORBA client)
JTRS Radio
Model
(CORBA Server)
Status &
Measurement
CORBA
Simulation
Engine
Control
Commands
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Steps in Methodology
• Design Time
• System Modeling
• Power Optimization
(1)
• Runtime
(2) ImpacctPro
• Simulation or Measurement
• Profiling
• Visualization
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System Modeling
• Architecture
• Considers dependency in the system
level context
• Captures mode transition overhead
Proc
on
• eg., 3D location, waveform, SNR, etc
• eg., messages (task)
on
Modem
• Application
• Parses mission profile to extract
scenario parameters and workload
Modem
on
Time
0.11
0.20
0.21
0.41
0.51
0.64
0.71
1.11
2.11
La..
0.31
0.31
0.31
0.32
0.32
0.33
0.33
0.41
0.41
2W/0.1ms
4W/1us
Lo.
-0.34
-0.34
-0.34
-0.34
-0.34
-0.34
-0.34
-0.34
-0.34
Al.
1000ft
1000ft
1000ft
1000ft
1001ft
1001ft
1001ft
1001ft
1001ft
stb
Wf
Link16
Link16
Link16
Link16
Link16
Link16
Link16
Link16
Link16
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Power Optimization
• Workload-driven
• Exploit idle periods
• Savings rely on input pattern
• Utilize non-operational
power modes
• Mission-aware
• Exploit scenario knowledge
• Adapt to scenario parameters
• Save active power
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Power Optimization
• Workload-driven
task
• Exploit idle periods
• Savings rely on input pattern
• Utilize non-operational
power modes
power
• Mission-aware
• Exploit scenario knowledge
• Adapt to scenario parameters
on
• Save active power
Resource
power saving
sleep
off
Full-ON
on
sleep
on
time
off
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Power Optimization
• Workload-driven
scenario parameters
task
Resource
• Exploit idle periods
• Savings rely on input pattern
• Utilize non-operational
power modes
power
power
saving
power
requirement
Full-ON
• Mission-aware
• Exploit scenario knowledge
• Adapt to scenario
parameters
• Save active power
full-on
low-on
time
mid-on
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Example: PA algorithm
Distance
Power
(ft)
(dBW)
1. Get distance from mission
profile
2. Translate distance to the
min. TX power using
communication equation
3. Get timestamped msg.
groups from mission profile
A
A
4. Assign Active PA modes
A
high
power
low
Time
(sec)
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Example: PA algorithm
Power
(dBW)
1. Get distance from mission
profile
2. Get timestamped msg.
groups from mission profile
A
I
I
I
I
high
power
A
A
3. Translate distance to the
min. TX power using
communication equation
4. Assign Active PA modes
I
I
low
5. Assign optimal Idle PA modes
Time
(sec)
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Example: Mission-aware
PA algorithm
1. Get distance from mission
profile
2. Get timestamped msg.
groups from mission profile
3. Translate distance to the
min. TX power using
communication equation
4. Assign Active PA modes
5. Assign optimal Idle PA modes
high
power
low
Time
(sec)
6. Output power command
sequence for PA
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Design Tool: ImpacctPro
• Modeling
• System description with power models
• Optimization
• Optimized power control commands
• Simulation and Analysis
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Hotspot identification
Power profiles of component, channel, system
Multi-granular, interactive GUI
Report generation
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ImpacctPro:
System Description
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ImpacctPro:
Real-time Simulation
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ImpacctPro:
Power Profile
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ImpacctPro:
Hotspot Analysis
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ImpacctPro:
Report Generation
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Simulation
• Simulated mission profiles including existing
UCAV mission scenarios with communication
activities
• Variation of mission length: 30 sec ~ 10 hrs
• Variation of message density: 0.1 ~ 24.4 msg/sec
• Our technique applied on
Rockwell Collins Step-2B
prototype
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Result 1. Energy Savings
Mission
Length
(sec)
Workload
(msg/sec)
Baseline
(J)
Optimized
(J)
Energy
Savings
m1
30
14.4
8136.9
1412.2
82.64 %
m2
80
24.4
21777.4
4572.9
79.00 %
m3
332
10.2
90330.5
17113.1
81.04 %
m4
480
12.3
130643.1
24960.0
80.89 %
m5
626
9.88
170184.2
30421.6
82.12 %
m6
3592
0.10
850921.0
91303/8
89.27 %
m7
35920
8.56
9750431.7
1617187.8
83.41 %
Baseline is the system’s power consumption without power management. In the baseline, PA
is assumed to be on RX mode (5W) instead of TX mode (372W).
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Result 2. Hotspot
Identification
Before
After
PA was the largest power consumer before
the optimization, which reduces its energy
from 45% to below 10%
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Result 3. Simulation Speed
90 times faster
than real time!
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Conclusion
• Power Saving
• Integrated mission-aware and workload-driven power
management to achieve substantial power savings
• Experimental results on realistic mission profiles
achieved 79%~89% energy reduction
• Tool
• Captured the new methodology in ImpacctPro for
systematic power management policy generation
• Provided a powerful design exploration capability
that guides the future system specifications
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Thank you !
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Related Work
• Dynamic Voltage Scaling (DVS)
• Processor centric
• May increase power consumption of other hw resources
due to extended execution time
• Overhead is often ignored
• Dynamic Power Management (DPM)
• I/O centric
• Devices are treated independently
• This work
• Captures all devices and their inter-dependencies
• Overhead is modeled
System Level
• Mission aware
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PA Transmission Power
• Minimum required PA transmission power can be
calculated by the following equation:
• Equation derived by our assumptions:
• Transmission Power depends only on the communication Distance
and the operating Frequency
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Simulation Time
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