Exploring coincidence-based network formation.


Jonah Brucker-Cohen and Katherine Moriwaki, Ken Greene, Linda Doyle, Stephen Hughes, Ronan Coyle


UBICOMP Nottingham, UK Sept 7-10, 2004 Paper: “Umbrella.net: Exploring Coincidence Ad-Hoc Networks” Poster Presentation

Ars Electronica Linz, Austria Sept 2-7, 2004 The Language of Networks Exhibition

Spectropolis City Hall Park, NYC, USA October 1-3, 2004 Exhibition Time: 12 – 4pm


9.20.04 News Frankfurt
9.02.04 The Register
8.13.04 Smartmobs.org
8.12.04 Unstrung.org
8.12.04 Daily Wireless
8.12.04 Gizmodo.com
8.06.04 DWeb
3.17.04 Neural.it
3.01.04 Rhizome.org
2.24.04 Corante: Many to Many


UMBRELLA.net is a project exploring transitory or ad-hoc networks and their potential for causing sudden, striking, and unexpected connections between people in public and urban space. The project focuses on the theme of “networks of coincidence”, or how shared, yet disconnected activities can be harnessed into collective experiences. UMBRELLA.net examines how the haphazard and unpredictable patterns of weather and crowd formation can act as an impetus to examine coincidence of need networks. In particular, when umbrellas are opened and closed in public space. The project will attempt to highlight these informal relationships by creating a system of ad-hoc network nodes that can spontaneously form and dissipate based on weather conditions.


UMBRELLA.net uses ad-hoc networking as a means to connect people who share the same physical space and who might engage in similar, yet individual activities. Since ad-hoc systems exist as networks that can spontaneously form and dissipate based on the amount of clients present, they are a perfect testing bed for examining how new relationships can form based on proximity and chance conditions. “Coincidence of need” can be defined as seemingly individual activities that are also common experiences based on factors beyond the individual’s immediate control. In the case of UMBRELLA.net, this is the act of opening one’s umbrella when rain begins to fall: an individual action spurned by an environmental effect that is part of a collective social network. Therefore UMBRELLA.net attempts to discover how coincidence of need provides the context for looking at co-location of individuals and how this need could lead to new types of connections amongst strangers or friends in public space.

Hardware design for the Umbrella.net project. This fit nicely around the main shaft of the umbrella.



3D Printed enclosure for the Umbrella.net electronics board and battery pack. The enclosure clipped around the umbrella shaft.


In Dublin, Ireland, rainfall is frequent and unpredictable. Often individuals carry umbrellas with them in case they are caught in a downpour. It is common to witness during a sudden and unexpected flash of rain, a sea of umbrellas in the crowded streets sweeping open as raindrops first hit the ground. This collective, yet isolated act of opening an umbrella creates a network of individuals who are connected through similarity of action, and intent. The manifestation of open umbrellas on the street could be tied to a temporary network which is activated through routers and nodes attached to the umbrella, which operate only while it rains. While the coincidence of need exists, the network operates. When the necessity of action and intent ceases, it disappears. We believe these transitory networks can add surprise and beauty to our currently fixed communication channels.



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Doyle, L., O’Mahony, D., Ad hoc Networks “A Welcome Disruption”, IST 2002 Event, Copenhagen, Novemeber 4th – 6th, 2002 [Invited Paper].

UMBRELLA.NET featured in:
Tribe, Mark, Jana, Reena., Art in the Age of Digital Communication, New Media Art,
Taschen, USA, 2006.