In recent years the dominant metaphor for pervasive location-based services has been a commercial one which posits people merely as consumers of pre-authored content chosen and served to them by network providers. Such services are typified by the prevalence of mobile tourist guides, listings services and restaurant guides – all of which have their uses, but essentially do little more than make pre-existing services of print and broadcast media available via wireless devices.

Real city life is richer and more complex than this, relying as much on social networks, personal experiences and chance interactions and connections. We believe that pervasive wireless/mobile platforms should attempt to reflect this richness and complexity, rather than re-purposing solutions designed for a different age. The peer to peer and multiple points of connections offered by internet-based networks present wholly new ways of inhabiting the city and communicating with the people around us in everday situations.

Urban Tapestries aims to privilege the experience of the individual over typical location-based services which control and author the user experience. Our model makes authorship and access to content the central relationship, enabling people to act as co-creators of the information embedded within the wireless and mobile environment, not merely as consumers of pre-authored content.

The Urban Tapestries model relies fundamentally on communities, not on service or network providers. It is intended to be a pervasive rather than ubiquitous service, rooted in locale and community. A local Urban Tapestry could be as small as a street, or as big as a district. It proposes that the kinds of information about the city that we need on an everyday basis are far more likely to come from our neighbours and colleagues than from large corporations or the media.

What Might Authoring Entail?
As part of the research into Urban Tapestries, we are working with potential users to try to imagine as many different uses for the model of public authoring as possible. Since the city is often described as canvas for its inhabitants to express themselves on and through, we are trying to devise a model that does not limit the creativity of its users. Some of the ideas we have generated so far for what authoring might be are:

• for local people (or former residents) to embed local history and memories of places in the places associated with them
• for local history archives to site their material in the places associated with it
• for schools to build up layers of local information gleaned from oral history projects, environmental studies etc
• for local people to create instant, geograpically-specific campaigns around local issues such as urban regeneration, housing or redevelopment
• for artists to create electronic artworks that are spatial and/or temporal
• for writers to create distributed narratives structured around place
• for games to be played through the city, such as electronic treasure hunts
• for friends to create pathways and gathering points for each other
• for people to create their own family histories, tracing places they've lived, where parents or ancestors met and married etc
• for people to share or swap resources within the community
• for lovers to map the spaces and routes of their relationship
  

Experiencing the City in New Ways
Western culture privileges the visual over other sensory perceptions, especially when it comes to information. But there are many ways to experience the world, and digital technologies offer a palette of possibilities for challenging the dominance of visual communication. One of the ways we are interested in exploring the recording and communication of experience is sound. Sound is indelibly linked to memory – often acting as a powerful trigger for recall.

One of the ideas we are exploring for Urban Tapestries is a facility to create 'sound maps' – audio clips of the sound environment recorded and edited together, a unique recording of a personal journey or experience. The sound maps would contain embedded links to geographic content on the Urban Tapestries system – something the users can share later with friends. Urban Tapestries thus affords its users a novel way of authoring their own experience of inhabiting the cityspace and communicating it to others via an album of memories structured around sound.

Profiles, Filters & Preferences
As the number of threads and associated pockets of content grows, it will become necessary to filter in and out the kinds of information people will wish to access through the system, as well as their authoring status. Proboscis is researching methods of creating personal profiles and the kinds of filtering technologies that would be necessary to navigate through a system well populated with content. We are imagining a series of techniques: from creating profiles that can be saved and exchanged between people, to inclusion and exclusion filters enabling people to only access specific content (by genre, date, author etc) or to block other types of content. We are also imagining ratings systems that can enable reputation systems to form between people who use and author to a local Urban Tapestry. We believe that such reputation systems could have significant value for different people within a community – for those who act as hubs of information and activity, as well as for those who need access to such information and places to interact.

Filters and preferences will need to be simple to change – reflecting the moods of the person as they move through the city. Since Urban Tapestries is primarily about everyday life, these 'mood filters' will need to be configurable on the fly – enabling a simple switch between moments when one is feeling expansive and inquisitive, to moments when one does not want to be bothered by external stimuli.

The Dark Side of Public Authoring
In addition to the benefits to be gained from open systems and public authoring, we are exploring the potential social hazards and costs that might arise from the emergence of new forms of communication. Just as with printing and telephones, any public form of social engagement is subject to abuse – from hate speech and entrapment to confidence tricks. Existing social and legal frameworks are well-equipped to deal with such problems without resorting to prior censorship – something that a democractic society needs to avoid at all costs. Our vision for public authoring acknowledges the potential dangers inherent in any self-regulated system, but we believe that the most appropriate form of regulation must come from an engagement with wider social and cultural forces than through a police action. Encouraging responsible use of public authoring systems by its users will not deny the possibility of abuse, but may deter malicious uses. Other means include requiring users to register on a central database (though keeping them anonymous from each other) and therefore warning that posting of illegal or unlawful material will be easily traced directly back to them by law enforcement agencies (such as all providers of telecommunications systems in the UK are currently required to do by law).

Social Knowledge
Traditionally knowledge is viewed as the preserve of experts – locked up in books and universities, created by and defined as the property of individuals or entities. Changes in value systems and perception of what constitutes knowledge have broadened and extended our understandings of what knowledge can be, where it resides and how it is created. Increasingly we are coming to value the kinds of knowledge bound up in the practice of everyday life, what we are typifying as 'social knowledge'.

Urban Tapestries is designed to allow its users to embed social knowledge into the fabric of the city via wireless and mobile networks, using a variety of geographic information systems to link memories, stories, histories, images, sounds and movies to specific places.

Social knowledge can be interpreted as encompassing both ideas and memories as well as behaviours. It is a term that attempts to indicate the broad variety of human activities, concepts and ways of being social: from how we interact with shopkeepers and follow routines of travelling through the city, to how we take part (or not) in communal activities. It could be described as the hidden or obscured resources and assets of a locale or of a community – created between and around people as they go about their daily life.

The Urban Tapestries model is intended to be accretive and organic rather than static, mimicking the ways in which knowledge is built up in communities and in society in general, a real-time micro-cosm of how our cities grow, thrive and die. It is intended to grow with time, at a pace set by its users, and to function as both a layering and excavation of the richness of experience and knowledge accumulated by its users.

Social Knowledge & Social Capital
As we come to define more and more clearly what constitutes social knowledge, so we are able to articulate its value; to make concrete what can often appear ephemeral, or intangible. Social knowledge can be understood as a form of social capital – something that has intrinsic value within a context of locality and community, if not a clear relation to monetary value. The more deeply embedded within a context such knowledge is, the harder it is to gauge its value – what systems like Urban Tapestries offer is a means to expose this knowledge and the social networks that support it, widening access and understanding of crucial resources.