Sensor Networks’ Integration - Application and Multidisciplinary Aspects of Wireless Sensor Networks - page 101

The authors therefore seek to incorporate embedded basic data protections into the
fundamental mechanisms of the network. The proposed architecture incorporates
the four entities below, and also existing network services such as trusted Certificate
Authority (CA).
• Sensors : These are data sources at the edge of the network; these are not simply
a pure source of data, but can also provide a control point to the external world.
These control points could be for the purpose of configuring the sensor or for
providing global contextual information.
• Subscribers : These are the users of the data provided by the sensors; individual
users of data or applications providing some value-added service.
• Registries : These are network services that help subscribers to find and bind
with sensor data streams. Sensors register here and subscribers query these in
order to find the sensors they want. The type of handle provided by the registry
is extremely important.
• Mediators : Nodes in the network that provide selected in-network functions on
sensor data streams. These services could be to perform verification of data
streams or to provide anonymization of sensors to subscribers.
In a typical deployment scenario, a sensor owner registers a sensor in Registry 1 via
the mediator Mediator 1. Registration contains sensor type, location, and context +
disclosure and verification rules. If sensor is mobile, it may change mediator over
time. The sensor then initiates data transmission to Mediator 1 - either on demand
or proactively depending on configuration. The role of Mediator 1 would be to act
as a privacy proxy and to provide a network testimony of the validity of the context
of the sensor.
A subscriber then sends a query to Registry 1 via a mediator Mediator 2. The
query has to go through a mediator since the sensor may have privacy rules depending
on the context of the subscriber, and Mediator 2 attests this context. The registry then
returns a pointer to the data streams. Mediator 2 can then bind to these data streams,
which means that in this case it binds to Mediator 1. Mediator 1 can now run its own
privacy rules and allow/disallow sensor data access.
The urban sensing architecture takes a very protective stance on participants, and
argues that network support is required for verification and dissemination of data.
By embedding support for these functions into the network, it is easier to efficiently
and securely execute them. Many issues around management of sensors/sensor net-
works are, however, not touched upon, and the underlying efficiency of processing/
context sessions are hinted at. The basic security architecture is only sketched.
CoBIs
The CoBIs project [ 20 ] developed a radically new approach to business processes
involving physical entities such as goods and tools in enterprise environments.
Advances in networked embedded systems were applied to embed business logic in
physical entities to create so-called Collaborative Business Items (CoBIs). Such items
enable to relate more closely the state of an enterprise as represented in a business