Transcript Mobile Middleware for energy

Mobile Middleware for
Energy-Awareness
Wei Li
[email protected]
Contents:
Definition and usage
Needs for Energy-Awareness Mobile
Middleware
A Solution
Summary
Definition
• The framework with which the mobile
devices make power adaptations
• Considerations: current battery status, local
CPU demand, and network environment.
• Hide the heterogeneity of low level platforms,
and thus enable the higher layers of the
system to build scalable solutions.
Target: prolong battery use time in the meantime
provide acceptable QoS
A typical usage scenario
1. Whenbattery
the train is going
throughmedium
a tunnelto low
3.
2. When
When the
the battery status
status drops
drops from
from high to medium
Lower the video
transcoding rate
Suggest user to stop
watching video when
the battery is even
lower
Put the network
Reduce backlight luminance
interface into sleep
Reduce the message sending
mode
rate.
Filter the messages according
to the priority
Contents:
Definition and usage
Needs for Energy-Awareness Mobile
Middleware
A Solution
Summary
Why we need such a middleware?
1. More and more multimedia usage.
Why do we need such a middleware?
2. Battery technology evolves really slowly
Comparison between two smart phones in ten years:
Nokia 9210 Communicator (2000) VS. HTC Desire (2010)
Hardware:
Processor :
Memory:
Camera:
52 MHz
16 MB
NA
1G Hz
576 MB
5 megapixel
Network:
EGSM HSCSD 43.2 Kbit/s
WCDMA/HSPA 14 Mbit/s
Software:
Don’t even want to start it
…..
Battery:
Li-Ion 1300 mAh
Li-Ion 1500 mAh
Why we need such a middleware?
3. Battery is the most restricting factor for Mobile phones
If we have more powerful battery?
Bigger screen, watch a couple of movies on the plane, charge once and use one
month
Why we need such a middleware?
Maybe someday…
charge our nuclear phone once and use it for the entire life
Why we need such a middleware?
Let’s get back down to earth
Before new technology in energy area, the energy-awareness
middleware is indeed needed
Contents:
Definition and usage
Needs for Energy-Awareness Mobile
Middleware
A Solution
Summary
The adaptations:
Local:
•
Processor voltage
•
CPU frequency
•
Backlight luminance
•
Network interface settings
Global:
•
Transfer some computation from the devices to remote
entities
•
Negotiated transmission
Architecture
Resource Manager
Target:
separate the low level resources
Functions:
1.
2.
Process the information requests
Control the hardware device
Application Classifer
Target:
Classify applications into different
classes
Resource consumption patterns:



CPU processing load {LOW, HIGH}
Memory access mode {STABLE,
BURSTY}
Network transmission load {LOW, HIGH}
Currently three classes:
audio/video decoder/encoder,
intensive network transmission,
extensive network transmission
Power Estimator
Target:
Estimate the power
consumption for the application
Component-level power modeling:
Unconcerned about application details.
Application-level modeling:
Power estimation for each application
Policy Manager
Target:
Make different power policies
Input: application classification,
network conditions, platform
settings…
Output: adaptive operations
Processing Engine
Target:
Responsible for scheduling
power adaptations automatically
The procedure:
1.
2.
3.
Subscribe to the resource
manager for events
Request for application
classification, power estimation
or policy
Execute policy
Messaging
Target:
1.
2.


Communicate with other
middleware and OS components
Communicate with remote
entities
Inter-process communication
(IPC) such as D-Bus is used for
the first target
HTTP is used for the second
target
Work flow
Step 1
Step 2
Step 3
Step 4
Step 5
Another policy
request and
execution
Evaluation environment and result:
• Device: Nokia N810 Internet tablet
• Download and playback content: a YouTube video
clip with duration of 257 seconds. File size 9472KB.
• Network environment: 802.11g WLan
• Result: the energy consumption is reduced by 8%
Contents:
Definition and usage
Needs for Energy-Awareness Mobile
Middleware
A Solution
Summary
1. Save the energy consumption while provide
an acceptable quality of service for mobile
devices.
2. Independent on operation system and
hardware
3. Possible to extend to a distributed
middleware with a proxy
Thank you for your attention!