The Design, Implementation &

Evaluation of Cells : A Virtual Smartphone

Architecture By :

Versha Thakur

Shravani Aishwarya

Introduction Smartphones- most necessary tools to carry nowadays.

Cells are used to enable virtual smartphone features.

Features like 3D graphics, power management, caller ID support etc.

Malicious software's can easily access data.

Solution – Virtual Machine (VM) Mechanism

Cells uses OS virtualization (run multiple VP’s on a single instance)

Tested on Google Nexus 1 and Nexus S phones.

Requirements

Support exclusive & shared access across VPs.

Sensitive information must never be leaked.

Prevent malicious applications.

USAGE MODEL

Cells runs on multiple VPs on a single hardware phone.

VP runs a standard Android environment.

Different level of access & permissions based on the function to be performed.

Switching of VPs depend on the level of access given.

VPs configured on a PC & downloaded to a phone via USB.

SYSTEM ARCHITECTURE

• Introduces New kernel- level mechanisms

• Device namespaces

Kernel –Level Device

Virtualization

• Introduces user- level device namespace proxy mechanism.

• Starting new VP, cell mounts the VP file system.

User- Level Device Virtualization

• Cells enable Linux Kernel Samepage Merging (KSM) for short time.

• Uses Android low memory killer – to increase total no. of VPs.

Scalability Techniques

GRAPHICS

Framebuff

er• Leverages Kernel-

level device namespace

• Driver (mux_fb)

• Multiplexes access to a single physical device.

GPU

• Replace Poor quality graphics

• Scenes in a video game, custom animations.

Power Managemen

t• Background VPs

should not be able to put the device into a low power mode.

• Should not prevent the foreground VP from putting the device into a low power mode.

Experimental Results

REPEATABILITY

Resources are not expensive or difficult to perform research

Requires a group of people with knowledge of many different topics.

REPEATABLE, if proper knowledge in all fields of software & hardware.

EXTENDABILITY

Done in 2012.

Android latest version (4.3) supports the user profiles.

Samsung released few devices – one click switch between Android & Windows.

Samsung is running two completely different OS on one device.

So research is already extended.

CRITICISM

Missing concepts such as Hardware virtualizations.

Latest cell phones are providing various multi-tasking features.

Only performed to run same OS on different VP’s.

If two different OS’s is implemented – increase the acceptance of the product.

Research on only one phone model Google Nexus.

CONCLUSION

Driven by virtualization mechanisms, device namespaces.

Virtualized critical hardware devices such as framebuffer and GPU.

Android’s complicated power management framework- no extra power consumption.

Cells provides each VP with complete use of standard cellular phone network by using VoIP cloud service.

Implemented on Google Nexus 1 and Nexus S.

REFERENCES

http://dl.acm.org/citation.cfm?id=2324876.2324877&coll=DL&dl=ACM

http://www.cs.columbia.edu/~cdall/pubs/Cells-SOSP-final.pdf

http://systems.cs.columbia.edu/projects/cells/

http://thecsbox.com/2013/05/cells-virtual-smartphone-architecture/

http://citeseerx.ist.psu.edu/viewdoc/summary?doi=10.1.1.231.5887