Chandrasekhar Narayanaswami

Reincarnating PCs with portable SoulPads

The ability to walk up to any computer, personalize it, and use it as ones own has long been a goal of mobile computing research. We present SoulPad, a new approach based on carrying an auto-configuring operating system along with a suspended virtual machine on a small portable device. With this approach, the computer boots from the device and resumes the virtual machine, thus giving the user access to his personal environment, including previously running computations. SoulPad has minimal infrastructure requirements and is therefore applicable to a wide range of conditions, particularly in developing countries. We report our experience implementing SoulPad and using it on a variety of hardware configurations. We address challenges common to systems similar to SoulPad, and show that the SoulPad model has significant potential as a mobility solution.

Application design for a smart watch with a high resolution display

Advances in technology have made it possible to package a reasonably powerful processor and memory subsystem coupled with an ultra high-resolution display and wireless communication into a wrist watch. This introduces a set of challenges in the nature of input devices, navigation, applications, power management, and other areas. This paper describes a platform we have developed and the decisions we have made about how to address these challenges.

User Interfaces for Applications on a Wrist Watch

Abstract: Advances in technology have made it possible to package a reasonably powerful processor and memory subsystem coupled with an ultra high-resolution display and wireless communication into a wrist watch. This introduces a set of challenges in the nature of input devices, navigation, applications, and other areas. This paper describes a wearable computing platform in a wrist watch form-factor we have developed. We built two versions: one with a low resolution liquid crystal display; and another with a ultra high resolution organic light emitting diode display. In this paper we discuss the selection of the input devices and the design of applications and user interfaces for these two prototypes, and the compare the two versions.

IBM's Linux watch, the challenge of miniaturization

Nearly four years in development, the IBM Linux watch contains a complete computer system that runs Linux, displays X11 graphics, and has wireless connectivity. The system fits in a case that could pass as a slightly unusual analog timepiece with a somewhat odd shape and an extraordinarily brilliant face. The developers have created two versions of the watch, one with an organic light-emitting diode display and the other with a liquid crystal display. Still considered a research prototype, the watch already runs some personal information management applications, and it can communicate with PCs, PDAs, and other wireless-enabled devices, viewing condensed e-mail and directly receiving pager-like messages. Eventually, users will be able to access various Internet-based services, such as up-to-the-minute information about weather, traffic conditions, the stock market, and sports.

Energy trade-offs in the IBM wristwatch computer

We recently demonstrated a high function wrist watch computer prototype that runs the Linux operating system and also XII graphics libraries. In this paper we describe the unique energy related challenges and tradeoffs we encountered while building this watch. We show that the usage duty factor for the device heavily dictates which of the powers, active power or sleep power, needs to be minimized more aggressively in order to achieve the longest perceived battery life. We also describe the energy issues that percolate through several layers of software all the way from device usage scenarios, applications, user interfaces, system level software to device drivers. All of these need to be systematically addressed to achieve the battery life dictated by the hardware components and the capacity of the battery in the device.

Fostering a symbiotic handheld environment

Although researchers have already begun building the infrastructure to make a symbiotic environment of handheld systems and related devices possible, business needs will drive this technologys real growth.

Personal mobile hub

As advances are made in wearable computing, there is a need for a personal mobile hub that can manage interactions between the wearable devices and act as a proxy for these devices. In this paper we describe why this is a good model, why the interfaces need to be open, and why different parties in the value chain, such as wireless service providers and device manufacturers, may prefer such architecture. Our personal mobile hub supports multiple wireless protocols, some short range and some wide area so that the power of the Internet is available even to body worn sensors. We describe custom hardware that we built for this purpose and also the software necessary to make this concept work. We have tested out this architecture with an end-to-end application. The working system was demonstrated at the annual IBM Stockholders meeting in 2004 and is also available for customers to see at the IBM Industry Solutions Lab in Zurich.

PAWP: a power aware Web proxy for wireless LAN clients

The relative power consumed in the WLAN interface of a mobile device is rising due to significant improvements in the energy efficiency of the other device components. The unpredictability of the incoming WLAN traffic limit the effectiveness of existing power saving techniques. This paper introduces a power aware Web proxy (PAWP) architecture designed to schedule incoming Web traffic into intervals of high and no communication. This traffic pattern allows WLAN interfaces to switch to a low power state after very short idle intervals. PAWP uses a collection of HTTP-level techniques to compensate any negative impact that traffic scheduling may have. PAWP does not require any client or Web server modifications. In this paper, we describe our initial experiences with a PAWP implementation for 802.11b WLANs. Our experiments show savings of more than 50% in the energy consumed by the WLAN interface. Finally, our experiences give us insights into possible browser improvements when power consumption is taken into account.

Unleashing the power of wearable devices in a SIP infrastructure

The session initiation protocol (SIP) has been widely adopted for instant messaging (IM) and VoIP telephony both by the enterprise and in service provider systems. Till now, SIP functionality has been accessible to end-users primarily via computing platforms such as an IM client on a laptop or on communication platforms such as an IP phone or a cell phone. We show that wearable devices such as the IBM Linux Watch (WatchPad/spl trade/) can play a powerful role as a control device in a SIP infrastructure, given their easily accessible, always available, and visible user-interfaces. We have designed and prototyped several key control applications, using a SIP User Agent on the WatchPad, such as the ability to initiate and route incoming and outgoing phone calls, receive simple queries as instant messages, and call initiation based on address books residing on wearable devices. We discuss other examples such as video conferencing and the authentication layer for workflow. Our investigation and implementation shows that wearable devices can plug an important gap and significantly enhance user experience.

Expanding the digital camera's reach

Digital cameras and large-capacity portable storage devices could soon be integrated into compact cell phones that establish symbiotic relationships with stationary devices in the environment, providing users with the ability to view and share images in many new settings and enabling the creation of several novel applications.