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"Wearable" devices -- what are they?
Research thrusts
Challenges loom
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Wearable wireless devices

Scott Stemberger (
Manager, Etensity
01 Jan 2002

Wearable computing represents the next big frontier in the push for the "always on, always active, always connected" environment of the future. Envisioned by some as a small hidden device with transmission and storage capabilities that is wirelessly connected to an ear-mounted speaker/microphone, most people think of wearable computers as more suited for Star Trek than for a shopping mall. This article discusses the status of wearable computers; the challenges faced by software and hardware manufacturers in developing effective and widely accepted wearable devices; and the commencement of a new paradigm for how wearable technology can create value for consumers and enterprises.

The terms "pervasive" or "ubiquitous" computing are thrown around fairly often by businesses and research organizations attempting to describe what is in store for the society of the future. These terms refer to a highly integrated and complex network of people and computers in which there exists a continuous stream of content and services provided to all members of society. Active and passive transactions are simultaneously executed based on user preferences, user location, and other designated data points that define what information should be presented to the user at precise times and locations.

Some organizations, such as Gartner, see the wearable trend as being an integral part of society. Gartner predicts that by 2010, 40% of adults and 75% of teenagers will be utilizing wearable devices, and 70% of the population will spend 10 times longer per day interacting with people in the e-world than in the physical world. Other organizations have echoed similar sentiments, citing the benefits of wearable devices as too big a value to ignore.

For instance, in the future, a "digital-persona" (your electronic profile that manages and defines your interactions with other computers and systems) may choose to allow you to snooze an extra 30 minutes because you received an update to your calendar stating that an 8:00 a.m. sales meeting has been postponed. Of course, this was done after checking the traffic report along your daily route to ensure you can arrive at work at your regular time of 8:30 a.m., and no other new tasks had fallen on your plate in the interim, which would require you to arrive early.

On your way to work, you are informed of gas and coffee specials with vendors along your route. You choose to get coffee now; you have enough gas and can fill up your gas tank after work. Once at work, you begin refining your sales presentation that has now been rescheduled for 11:00 a.m. at another building. Reviewing your presentation while walking to the other building, you notice a spelling error and fix it immediately. Upon arriving at the meeting and preparing to deliver your presentation, the presentation is immediately uploaded into the computer attached to the projector. As you begin, you are informed via instant message that some members in the room are not being acknowledged by the face recognition system. Your digital persona suggests removing a later slide with sensitive pricing information; you agree, and the slide is instantly removed, all done behind-the-scenes while you continue speaking.

Upon completing the presentation, you are packing up when an urgent e-mail arrives from your boss regarding a client emergency. You quickly finish and rush to his office, reading the e-mail while simultaneously calling his secretary to let the boss know you will be at his office in 10 minutes.

"Wearable" devices -- what are they?
The scenario described above is more of a reality today than many people realize. As an example, the concept of "smart spaces," or physical locations that react differently as different people move in and out of them, already exists to some degree. A smart space combines building and technology infrastructure, allowing things such as temperature to be adjusted in a room based on an individual's physical presence and associated digital persona. In the future, personalized physical attributes will be augmented by an individual's information needs. Increasingly, localized interactions with the space around you will create value and efficiency for corporate citizens, while improving the quality of life for society at large.

Although other technologies surely must continue to evolve in order to enable true pervasive computing, wearable devices clearly bring with them the greatest amount of value and are likely the final piece of the puzzle. Today's handheld computers and other assortments of mobile devices (pagers, phones, PDAs, PDA watches, etc.) offer a glimpse of where the industry is moving as the devices continue to decrease in size, while seemingly improving in functionality. Ultimately, these devices will become integrated in such a manner as to provide minimal distraction to the user by not preventing them from performing other tasks (cooking, for instance), even as they utilize the device (read e-mail).

Wearable computers are miniature devices that enable a user to conduct computerized tasks with 100% portability and freedom, all nearly transparently. Wearable computers are integrated within our wardrobe and lifestyle, so as to appear invisible, offering a multitude of input and output mechanisms that allow a user to continue with other tasks even as they interact with the computer and environment around them. Additionally, while the advanced functionality of today's handheld devices has severe form factor implications, wearable devices of the future will likely function more as thin clients, providing device manufacturers more latitude in absence of the excessive battery and processing power requirements tied to today's devices.

Research thrusts
In order for wearable devices to gain critical mass, the concept of pervasive computing must continue to evolve, allowing wearable and non-wearable fixed devices to interact in a seamless fashion. For this to happen, industry players must continue to perform advanced R&D and to strike partnerships for combining efforts and making advances. Following are descriptions of three areas where considerable progress is being made:

Smart spaces
Smart spaces, such as an enclosed meeting room, store, corporate building, or shopping mall, will bring with them increased usability and functionality for all wirelessly connected mobile devices, including wearable computers. As business- and consumer-focused organizations integrate smart spaces, mobile device owners will feel more inclined to utilize mobile and wearable devices, which allow them to seamlessly interact while at work and at the grocery store. The value proposition inherent to smart spaces -- thin clients, interactive digital persona, location, and time sensitive data -- are not novel concepts, yet are much more realizable with the use of smart spaces and their ability to easily deliver highly prioritized localized interactions that will motivate the mobile user of the future.

As an example, the 802.11b WLAN offers this capability today to corporations deploying WLAN stations in strategic locations. WLAN stations can be configured to restrict access to sensitive content in certain physical locations, and restrict user access altogether. Streetbeam is an outdoor solution; their Remote Access Mobile Point (RAMP) continuously beams out a message prompting users to accept advertising information. This information, typically location-specific, is transmitted via infrared to the device once the supporting display application has been downloaded.

Input/output (I/O) mechanisms
I/O mechanisms are a key component to the success of wearable devices. The ability to easily and non-obtrusively interact with a device and the surrounding environment is paramount for wearable devices to differentiate themselves from non-wearables.

For example, Sony Computer Science Laboratories has been performing cutting-edge research on input technologies, and two of their ideas, called GestureWrist and GesturePad, could be something we are all using by the end of this decade. With the goal being to make inputs to your wearable device as conceptually unnoticeable as possible, GestureWrist is a wristwatch-type input device that recognizes human gestures by measuring changes in wrist shape and forearm movements. Networked to a visual display, GestureWrist could serve as the user's virtual mouse.

Companies such as Xybernaut have produced wearable devices capitalizing on more traditional I/O vehicles. Xybernaut, who's core customer is Bell Canada, offers a hands-free wearable computer that includes a body-worn, voice-activated, high-power processor and a VGA color flat panel or head-mounted color display with microphone and eyepiece, through which the user sees a video display. The battery-powered central computer weighs less than 2 pounds, and clips onto a vest or belt. The 1.1-inch head-mount display has an optional miniature video camera or palm-size color touchscreen that straps onto the arm. (Bell Canada trial users claimed to have saved nearly an hour a day.)

A key advantage of wearable visual displays rests in their ability to project an image that appears similar to that of a PC from the user's vantage point. This output mechanism will likely become very popular as it continues to evolve and better integrate with current eyewear. Voice remains a prospective option in both input and output technology, as well.

Invisibility and social acceptance
To be adopted by mass markets, wearable devices must become completely integrated with the user, so as not to appear unusual or prevent standard physical interactions such as shaking hands. By integrating with glasses, watches, and shirts, wearable devices become nearly invisible, allowing the user to conveniently multitask while not impeding physical activity or interrupting other personal interactions.

The other Sony prototype mentioned -- GesturePad -- is an exploration into "interactive clothing," which is certainly a step in the right direction. GesturePad is a small pad that can be inserted into traditional clothing, thus transforming the clothes into interactive devices. GesturePad is actually a thin layer of sensor electrodes that can detect finger motions applied to the outside of clothing fabric. A GesturePad inserted into the lapel of sport coat could control a PowerPoint presentation, the volume of an MP3 player, or the scroll bar of a Web page being projected from a person's eyewear. Furthermore, multiple sensors could be inserted into any individual clothing item, each having a specific function.

Watches provide a clear avenue into which wearable computers have already began to infiltrate. Fossil, one of America's leading watch companies, recently announced a new Wrist PDA, featuring both Palm and PocketPC versions. The watch provides read-only content, with current support for infrared beaming as the transfer technology between handheld PDAs and the Wrist PDA. The watch can store up to 190k of primarily PIM-type (Personal Information Management) data such as contacts, schedule, to-dos, and memos.

IBM and Citizen Watch Co. recently joined forces to deliver IBM's WatchPad, a prototype wearable computer. The WatchPad features a 320 x 240 monochrome VGA display, Bluetooth and infrared wireless connectivity, and speaker, microphone, and fingerprint-sensor functions. The goal of WatchPad is to begin delivering new human-computer interactions, such as using a watch to control a presentation or other nearby devices, and to receive, deliver, or store pertinent information.

Hypercom Corporation and WearLogic announced their alliance, which will allow consumers to use WearLogic's leather pocket wallets for wireless payments at checkout counters using Hypercom terminals. WearLogic claims to have proprietary technology that can transform a traditional leather wallet into a mobile financial device containing a flexible screen, ATM-like soft keys, and an intuitive keyboard. Users can track financial account information, purchase products in physical and electronic environments, and download and store Web-based information such as addresses or driving directions.

Challenges loom
While research and commentary often focus on the physical attributes of wearable devices, many challenges come from both the hardware and software perspectives.

Thick or thin
The debate for how thick or thin a wearable client should be continues, as we have no idea what our functional requirements or hardware limitations will be in the future. Today, a thick client represents more CPU power, memory, and disk capacity, which translates to a larger, heavier device that requires a bigger battery and dissipates more heat -- all negatives when conceptualizing a wearable device that ideally is invisible to the casual eye. Over time, it is rationalized, packaging and other technological advancements can and will reduce the physical size and weight of a thick client. However, thin client enthusiasts argue that these same advancements can be extrapolated to a thin client device, making the device even lighter and smaller.

Ultimately, there is no such thing as a device being too small or too light for a mobile user interested in a wearable device. However, the user must take into account the worst-case scenario of no network connectivity, and determine what functionality is absolutely essential 100% of the time, even in non-connected states.

Battery power
The proactive and self-tuning nature of wearable devices will increase the energy demand of software on that device. In contrast, the pressure to make wearable devices as small, light, and unnoticeable as possible places severe constraints on battery capacity. There is a growing sentiment that advances in battery technology and circuit design cannot overcome these two opposing issues, and that higher levels of system management must become involved. One idea proposed by researchers at Carnegie Mellon is energy-aware adaptation, in which individual applications switch to modes of operation with lower fidelity and energy demand under OS control. Another possibility is an OS that can dynamically control the amount of physical memory that has to be refreshed. Finding high-level energy management techniques will be an ongoing and interesting challenge to watch.

Another key challenge for wearable computer enthusiasts will be usability. The user experience in the wearable industry will be defined by multiple facets: consistency, contextual awareness, and adaptation. Consistency refers to an identical experience across different environments and locations. If a user is accustomed to receiving certain alerts and information pushed to them when in certain locations, what happens when they visit another similar location that lacks the smart spaces or other infrastructure to deliver the same experience? Adaptation refers to the environment's ability to detect a lapse in service or service unavailability, and adapting to the situation by recommending an alternative solution where resources or services exist and are more plentiful.

Finally, contextual awareness refers to one's digital persona, and the ability to obtain and store rich user information beyond preferences and location. This includes traits such as physiological (heart rate, body temperature) and emotional states, and how those attributes can be used in conjunction with other location- and time-specific data to determine a course of action or to guide an interaction. Should the device be proactive or transparent right now? Does the user want to receive this phone call? Is this message important? What is the user's intent during this task right now?

A wearable device's ability to handle these type of inquiries while delivering a consistent user experience is what will truly drive wearable devices to reach critical mass.

Naturally, privacy and protection of personal information remains at the top of the list for challenges of the intelligent, ubiquitously connected society. As stated previously, pervasive computing requires proactive interactions by mobile and wearable devices, based upon location tracking, smart spaces, movements, behavior patterns, and general habits. This information must be monitored on a continual basis, causing severe security concerns and implications for the user. Many users may fear that this information could get into the wrong hands and be put to foul use, resulting in them choosing not to rely on a pervasive computing system for fear of a violation in trust and privacy.

Similar to the energy problem, a contradiction of requirements exists here as well. A larger reliance on the pervasive environment around a user requires more trust by the user in the devices and infrastructure composing that environment, even as some users today feel uncomfortable using their credit cards online. Conversely, the pervasive environment needs much more information about users in order to ascertain a user's identity and authorization, and this level of information is much greater than what users will provide today. Gaining confidence and mutual trust between the user and system will be challenging to say the least, and ultimately may prove to be the biggest barrier to wide-scale adoption of intelligent wearable devices.

Pervasive computing remains our technology pinnacle, a utopia of sorts where users are always on, always active, and always aware. Wearable devices will be a key component in enabling pervasive computing to transform our society into a networked one -- where a digital persona will constantly analyze data and make decisions to provide access to content, services, and entertainment for anyone, at any time, in any place. Indeed, wearable devices will pave the way for gains in mobile computing that entirely transcends our current set of mobile devices and advantages they offer today.

Of course, this change will not occur overnight, as we can only move as fast as the technology evolves. Companies like Levi Strauss are already looking to capitalize on the wearable concept, offering a line of jackets that incorporates a hidden MP3 player and mobile phone connected to a remote control and microphone in the collar. Peer-to-peer technology companies also continue to proliferate, with peer-to-peer technology perhaps playing an important role in the energy conservation challenge associated with wearable devices.

Of course, even as we hear about wireless wallets and interactive clothing, we are occasionally informed of real mind-numbing advancements like those by the Israeli scientists who developed a DNA computer so tiny that a trillion of them could be combined to perform a billion operations per second, expanding our horizons and challenging issues we might have viewed previously as insurmountable. DNA computers currently have no business implications, implying that some people aren't too interested.

However, if I told you that these DNA computers are being considered for potentially operating within human cells and acting as a monitoring device to detect disease-causing changes and synthesizing drugs to fix them, does the term "wearable computer" and proactive interactions take on a new meaning?

About the author
Scott Stemberger has over five years of experience in leading large software, Internet, and wireless implementation projects. He is currently a manager at Etensity, an Internet consulting firm based in Vienna, VA, where he cofounded the company's wireless solutions practice. Prior to joining Etensity, Scott worked for Boeing. He received his B.A. from the University of Virginia, and an M.S. in information systems from George Washington University. You can e-mail Scott at

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