With the SoulPad model of personal computing, an insurance adjuster may use a small tablet computer while in the field during the morning and then move her computing session to a desktop computer at the office in the afternoon and continue her activity. The idea is that the small tablet computer may be more suitable for certain tasks such as data entry but a desktop could be more suitable for other tasks such as finalizing claims processing and that the user can use the most ergonomic and convenient device for the task. Likewise an aircraft maintenance engineer may switch between a wearable computer with a head-mounted display and a more powerful desktop computer during the course of his work day without losing his session state.
In another example, users can simply carry a SoulPad between home and work instead of carrying a heavy laptop computer. Students could carry SoulPads to classrooms and utilize computers present there without breaking their backs carrying heavy computers or books between home and school.
Users in some parts of the world may prefer to just own a SoulPad, perhaps integrated into a cell phone, to avoid the cost of purchase and maintenance of a complete PC. Such users may attach their SoulPads to PCs available in ubiquitous internet cafes.
The conceptual elegance of the three layer SoulPad software stack is central to its appeal. The three-layer SoulPad software stack enables a paradigm of mobile computing where a user can suspend his computing environment on one PC and resume it on another PC that he may have never seen before. The PC boots an auto-configuring operating system from the SoulPad, starts a virtual machine monitor, and resumes a suspended virtual machine that has the user's entire personal computing environment, which includes the user's files, user's operating system, installed applications, desktop configuration as well as all running applications and open windows. Essentially, SoulPad enables a user to hibernate a PC session to a pocket form-factor device and carry the device to some another PC and resume his session on that PC. SoulPad has minimal dependencies on PCs that can be used to resume a user session. In specific, PCs are neither required to be network connected, nor have any pre-installed software. The only requirement is the support of a high speed local connection to a SoulPad device for an acceptable suspend/resume times and acceptable runtime performance.
Figure 1 : SoulPad software stack and image sequence showing usage model. |
The insight of combining portable storage, auto-configuring operating systems and virtualization technology was a key research contribution. Since this realization, one of the first challenges was to get the time to suspend and resume a session to be within acceptable limits. Lower suspend and resume time make the technique attractive in a wider range of situations. The time to resume includes the time to boot Knoppix (an auto-configuring OS) and the time to resume the suspended virtual machine. We eliminated non-essential elements in the Knoppix startup sequence and used fast disk drives to reduce the overall resume time. The resume time is around two minutes and the suspend time is around 30 seconds. On our disk drives we allocated 4GB of storage for the Knoppix partition and 2GB for a swap partition. The remaining space on the drive is available for the user's guest operating system, applications and files.
Since the SoulPad is a small portable device, the chance of losing it increases. We had to deal with the security implications of this scenario and presently address them by encrypting the contents of the user's virtual machine. Some of the remaining challenges include evolving the technique to exploit the native hardware on the PC to the fullest extent such as exploiting newer instructions on PCs with newer processors, reconfiguring the virtual machine to utilize the available memory on the host PC instead of using a fixed configuration for the virtual machine, etc. Another goal is to further improve the overall security of the technique.
The SoulPad model of personal computing has the potential to significantly change the PC ecosystem. A user may have several personal computers that he uses at different times with the same SoulPad and thus manage and administer a single SoulPad instead of several PCs. As a result, providing a personal computer in a hotel room or in the back seat of an airplane becomes a lot simpler since the hotel or airline does not have to manage it. PC manufacturers could provide elegant methods to attach and detach SoulPads.
The SoulPad software stack could be integrated into several popular devices that people already carry - such as cell phones, music players and digital cameras and thus fundamentally change the way they are used and built.
IBM has protoyped several innovative concepts in the mobile computing area. Past work on Portable Personality, the Linux Watch, the MetaPad and the Personal Mobile Hub played an important role in germinating the SoulPad. We analyzed the limitations and strengths of each of the earlier efforts and factored in recent improvements in technology and believe have created something with significant user appeal.
Related Publications
Ramon Caceres, Casey Carter, Chandra Narayanaswami and Mandayam Raghunath. Reincarnating PCs with Portable SoulPads. ACM MobiSys. June 2005 (Best Paper Award).
News and information
PC Magazine: The Soul of Your Machine
Associated Press: ABC News Capturing the Ghost in the Machine -
Associated Press: USA Today Flash drives make any computer 'personal' -
Technology Pundits - Analyst Tim Bajarin - Innovation is Alive and Well at IBM
NewScientist.com - Pocket-sized computer 'soul' developed
LinuxDevices: IBM decouples PC "souls" from "bodies"
CNET: IBM brains capture a PC's soul
Financial Times: An out of body software experience
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Innovator's corner
Chandra Narayanaswami Researcher
What is the most exciting potential future use for the work you're doing?
People will be able to have new user experiences while carrying powerful yet small portable devices and by leveraging rich services and other devices in the environment.
What is the most interesting part of your research?
The mobile and wearable computing area is developing rapidly and practically changing the way we communicate, entertain and take care of ourselves, and work. Having the ability to influence how this field evolves is invigorating.
What inspired you to go into this field?
As a young boy I felt that scientists were really changing the world.
What is your favorite invention of all time?
Electricity
Research team
Related Research
Disciplines: Computer Science
Research Areas: Mobile Computing
Research Labs: Watson Research Center