Hybrid Positioning Technology with Broadcast TV Signal and GPS

I listened Todd Young talk at last summer’s Where 2.0 conference. Todd is the Director of Product and Business Development at Rosum Corporation, a company that has developed a way to use unmodified broadcast TV signals for positioning in these places where GPS often fails (my previous post on this). These signals penetrate buildings and are already available worldwide. In fact, they have an hybrid solution that uses TV signals and GPS. Their RTMM device uses multilateration of TV signals and a centralized server when GPS fails to get a fix.

The main advantages of positioning with TV signals is that if works indoors and the infrastructure is already in place. The (major) drawbacks it that it relies on a centralized location server. It means:

• the need of coverage by another wireless technology
• there is the cost (price) of data transfer to calculate a position
• privacy issue in having a centralized server calculating a position
• manage a database of a gazillion antennas (well probably a bit less in the US). In the US, the FCC probably has an open database, it might not be the case in Europe/Asia.
• it relies on broadcast television, while the US and european markets are moving to wired television.

no 3D positioning, the elevation can very hardly be calculated

Currently, their first generation device is “unusable”. It is too big to be integrated into mobile devices like mobile phones. Todd mentioned that we have to wait for their engineers to get into the 4th generation in order that have that happening.

Todd mentioned that Rosum’s customers ask for security and live saving applications (clearing thinking E911 and police/firefighter location here) and even tracking high risk parolees. It does not come into a surprised that Rosum is partially founded by the CIA Not really surprising the CIA-backed venture firm In-Q-Tel

Rosum’s system would come really interesting for a broader market if it did not have to rely on a centralized location server. They have a mention on the technological feasibility on their web site
Note that location could be determined autonomously without a centralized location server at the RTMM under the following situations:

• TV signals were all synchronized to a common clock
• Timing information for the TV clocks could be provided over-the-air as a part of the TV signal.

Capitalizing On The Location-Based Services Opportunity

I wanted to get some update on the JSR-179 implementation and stubbled on Capitalizing On The Location-Based Services Opportunity, a March 2005 document by Nokia for their developers community. It is strange to notice Nokia pushing for A-GPS solutions while my understanding was that Nokia (unlike Motorola) did not want to embed GPS into their products. I could also spot some irony in “Applications that use LBS are limited only by developers’ imagination“. This has to be ironic, right!?. Anyway, it is still not clear to me on how much the JSR-179 Location API allows us to develop terminal-resident (better for privacy and less dependent to operators) rather than network-resident applications. I’ll need to get myself a JSR-179 enabled device in order to really find out I guess.

The document mentions the usual application opportunities (all related to billing models and positioning technologies, of course):

• Mapping, navigation and directions application, and the ability to combine them with other services
• Workforce tracking
• Entertainment and gaming
• “Finder” that helps to locate friends and things.
• Location-enhanced imaging
• Weather applications
• Location-based reminder

On the semantic of privacy, it is interesting to notice that people allowing other to locate them are considered as “friends” and never as “employees”.

Ubicomp, Limitations, Failures and Malfunctions

Starting to set a framewok:

Ubicomp, limitations, failures and malfunctions
The increasing ubiquity of computer and their diffusion into our environment requires reconsidering the complex interplay between technology and the human. While technology providers suggest that there are not limits to connectivity and mobility, service coverage and stability is anything but seamless in the real world. Moreover, since the infrastructure structure is meant to be invisible it will be necessary to develop an understanding of what failure means and how malfunctioning is communicated to the user.

For the moment there has been papers on the impact of uncertainties on individual experience, not on individual and group performance at a task. The closest works are on rather ethno-oriented-interaction design Defining Uncertainties in Can You See Me Now? (on the user experience of uncertainty) might be the psycho oriented Evaluating the Effects of Displaying Uncertainty in Context-Aware Applications (that shows that memory task is increased by explicitly displaying uncertainty information, and we have to be careful with the workload generated by showing uncertainty information.

Phenomenon of uncertainty
Sources of uncertainty in ubicomp environments are due to technical limitations (communication latency, deviations in positioning, data synchronization, fluctuating signal strength, power consumption, autonomy, processing and overall system complexity) and sometimes economical limitations (patchy network coverage and cost). I have to understand more the socio-psycho impacts or uncertainty.
High-level questions
[Group coordination in unstable ubicomp environments]
How do groups establish a shared context and coordinates their actions in real-world ubiquitous systems prone to failures and malfunctions?

[Detecting uncertainty]
How do users detect uncertainty and what are the clues?

[Impact on the users]
Understand how people use and react to discrepancies and sources of uncertainties in ubicomp infrastructures. More precisely, How do users know and learn how to avoid and rectify the system’s mistakes (e.g. learning to detect the seams and cold spot.

[Impact on the group]
How do groups address the difficulty of ubiquitous systems (e.g. when lost of connectivity, positioning accuracy)?

Specific questions in CatchBob!
Variables at disposal for each player:

• Elapsed time (in seconds)
• Times (in seconds) with no, bad and good positioning accuracy
• Connected and disconnected times (in seconds)
• Ubiquitous index with positioning accuracy and connectivity
• Attempted synchronization
• Failed synchronization
• Words sent
• Nasa Load Index
• Mental load
• Physical load
• Areas covered (the campus is divided in 20m2 areas)
• Back path (player returning on his footsteps)
• Covered path (number of areas covered by another player)
• Players representation of each other’s path
• Meanings of annotations (direction, strategy, acknoledgement, question, order)

Conditions where with awareness tool (aka automatic positioning) and without awareness tool (manual positioning). 10 groups for each condition.

Strategy and uncertainty

• How did users react to bad connectivity and positioning accuracy and how did it affect their strategy? Did they return on their footsteps? Did they exchange more messages? What are the meanings of the messages?

Uncertainty and task performance

• What are the impacts of bad connectivity and positioning accuracy to the accumulated paths and the numbers of areas covered

Perception of uncertainty

• Are users sensible to loss of connectivity (because our connectivity numbers are rather good, but many players where verbose about the experience of positioning and connectivity)
• Did bad connectivity and bad positioning increase the work load (Nasa Index)?
• What is the representation of the other players path in a situation of bad connectivity and connectivity?

Approach
Mix of qualitative and quantitative data. Investigating the processes rather than the outcomes. By processes meant the interaction with the artefacts/application/service but also the group processes when they collaborate using it. The outcome or the performance is often less intersting than the processes that occured.

Seamful Design for Location-Based Mobile Games

In Seamful Design for Location-Based Mobile Game, Gregor Broll (Embedded Interaction Research Goup in Münich) and Steve Benford (Mixed Reality Lab) present Tycoon, a location-based multiplayer trading game that uses the different GSM cells within a designated gaming area. This paper do not talk about any results in using the game, but rather how they designed Tycoon to show seams of the ubiquitous environment when needed.

The sources of seams due to technical limitations are plentyfull in many ubicomp systems.

Patchy network coverage, fluctuating signal strength, deviations in positioning and the generally limited resources provided by mobile devices are an everyday reality for their users. Usually they experience these limitations indirectly as sketchy and slow mobile internet access, variations in the quality of speech transmission, loss of connections or ambiguities in positioning. Contrary to seamless design, seamful design tries to reveal inevitable seams in ubicomp systems and use them to increase the awareness for system infrastructure, their heterogeneous components and otherwise neglected yet useful information within the system.

Mark Weiser is that the source of seamful design

As part of his vision on ubiquitous computing, Mark Weiser called for invisibility as a general design goal of ubiquitous computing and especially for invisible tools that don’t intrude on the user’s consciousness but let him focus on the task and not the tool itself. [...] Despite its benefits of comfort and simplicity, the paradigm of seamlessness is questioned. Mark Weiser actually opposed it as a misleading concept. Instead of making everything the same, reducing different component in a seamless system to tht level of a “lowest common denominator” and sacrificing their uniqueness for the goal of overall compatibility, he calls for “seamful systems” which paraphras as: “making everything the same is easy; letting everything be itself, with other things, is hard”.

Inaccurate positioning is a very common seam. People using positioning system experience those seams as uncertainties about their current position. In seamful design it is important to indentify 3 key problems:

• understanding which seams are important
• presenting seams to users
• designing interactions with seams

Giving the ability to play with the seams may ultimately lead to the more general concept of designing for appropriation.

Design for appropriation allows users to interact with seams individually, take advantage of the gaps and limitations in ubicomp infrastructures and develop new patterns of behaviors that have not been considered during the initial design of the system.

Key references:

• Weiser, M.: The world is not a desktop. ACM Interactions 1(1) (1994) 7-8.
• Chalmers, M., MacColl, I.: Seamful and Seamless Design in Ubiquitous Computing. Technical Report Equator-03-005, Equator [Technical Reports] (2003)
• Weiser, M.: Creating the invisible interface (invited talk). ACM Conf on User Interface Software and Technology (UIST94) (1994), 1

Via Pasta and Vinegar

Symbian Educating its Developers to Location Based Services

In February 2004, John Pagonis and Jonathan Dixon of Symbian (OS for smartphones) published a very refreshing article to educate their developers’ community to Location Based Services. They briefly explain context awareness, location awareness and location based services. The perspective is clear:

What is of interest is what we can do with location awareness rather than how much awareness is implemented or delivered to the device. [...] Unfortunately when talking about LBS, most developers and users think in terms of static user-initiated scenarios like finding the nearest taxi rank or getting a map proximate to the user’s position.

and they even go into mentioning manual positioning

Many times it suffices for a location awareness application to be useful for the user to manually inputs its approximate location to the device

They clearly explain the difference between accuracy and precision

All quantitative properties provided by location acquisition technologies have a realted accuracy (or error or tolerence) and precisions (of confidence). Coarsely, the accuracy is a mesure of how far off the data may be and the precision is what statistical percentage of the time the actual (or measured) error will be within the accuracy estimate. These are a function of the acquisition technology, and current (and maybe past) operating conditions. Qualitative information can only have a confidence.

and mention a “graph of confidence over accuracy”

In actual fact, this will be a graph of confidence over accuracy, forming some sort of curve, such as a Gaussian distribution, that will itself be a function of the acquisition technique is use.

They also come up with interesting insights and conceptsincluding:

• “Local positioning” which make use of short range networks
• We should not expect the support of E911 and EU E112 to be exposed to developers
• Human-Device-Network interactions
• Constraints include power consumption, cost, autonomy, speed, networking, autonomy, processing and overall system complexity.

Unfortunately, part II that is supposed to talk about application scenarios is nowhere to be found and maybe was not ever written…

Where Are the Other Mobile Buddies Around Town?

The WOMBAT (Where Are the Other Mobile Buddies Around Town?) written by people from BT, T-Systems, Portugal Telecom and Elisa Communication, talks on the feasibility to introduce location based services to fulfill the demands of the youth market considering today’s technology constraints. It particularly focuses on how positioning technologies can aid young people micro-coordinate (making arrangements while on the move). By making a lot of over-simplifications and using basic usage scenarios their result show that:

Virtually no positioning technology is able to meet the requirements, and only by limiting the service offering in terms of accuracy and usage environment, can some of the current technologies begin to meet the needs of the youth market.

They explain the lack of acceptance of LBS by young people is due to technical limitations. We know it is more complicated than that. They make references to very general findings on how young people use mobile technologies (an intrinsic part of their lifestyles, communication is key, peer groups, mainly used indoors) without really trying to understand the habits of coordinating and their social impacts.

Nicolas has interesting words about it.

The Right Time to Cease LBS Services

Cingular announced it will cease its mMode LBS offering “Find Friends” and “Find Things Nearby” in January 2006. Their spokesman mentioned:

Our active number of subscribers that use this service on a weekly basis has dwindled significantly, we have determined that this is the right time to cease our LBS services on mMode.

LBS and Child King

AeroScout seems to have some valuable solutions in outdoor real-time asset location (RTLS), asset tracking, and patient and staff location in large hospitals. This week they announced a Wi-Fi-based location tracking solution “to reduce accidents and crime involving Japanese schoolchildren”. Scenarios include:

• Automobile drivers are alerted to the presence of nearby children through a voice service, to reduce accidents in residential city areas.
• When a child reaches pre-set points along their route, the system will notify their guardian
• a child can call for help by pressing a button to immediately alert their guardian.

It is fair to ask how such solution can damage the relations that kids build with their environment (testing the limits) by making it so “safe”, how it affects the parents-child relationship (trust relationship) and eventually shape an “enfant roi” (child king).

Mobile Search, Wayfinding and Matchmaking

Many LBS scenarios deal with mobile search, wayfinding, and converting strangers into friends. They have that in common that they are pretty useless in areas known by the users (home, office and many third places). We do not necessarily need assistance to find out everyday stuff (the closest post office from my home?), how to navigate in these areas, and in artificially making acquaintances. This leaves these mobile LBS being sparsely relevant to unknown areas.

2 posts talked about it lately:
Wayfinding, GPS and social navigation by Nicolas quoting Jan in future perfect.

“Mobile with GPS and map application. So you want to make a map reference in a hurry? “It’s easier to just ask someone” In many instances so it is“.

Is Mobile Search About Local? by Russell in Mobhappy:

Most people actually know the area they live and work in pretty well and don’t need our assistance to find out everyday stuff like this.

Russel also talks about the Need to Know Now Factor (N2KN) being often not really relevant to location and mobility:

The N2KN factor may indeed have a local element to it from time to time, but Local won’t be the factor that actually stimulates the Search. In the short to medium term, when mobiles are so much slower and clumsier to use than computers (or even Yellow Pages), being motivated to use mobile search is going to depend on how urgently you need the information and how important it is.

Scale-Free Networks

In his course on Web Characteristics and his project on the Characteristics of the Web of Spain, Vicente Lopez talked about the properties of scale-free/power law networks that are common in social networks. These networks also exhibit the Small world phenomenon, in which two average nodes are separated by a very small number of connections (The Six Degrees of Duncan Watts, Properties of the Kevin Bacon Absorbing Set, Small World Project at Columbia University).