Sensor Networks’ Integration - Application and Multidisciplinary Aspects of Wireless Sensor Networks - page 83

a WSN gateway. With SNIF, the access to the WSNs via a standard interface will
be much easier and will require a minimal effort from the service providers.
Some of the major advantages of the SNIFs are the mechanisms which enable
security of shared resources against misuse, provide estimates of reliability or veri-
fiability of sensed data against malicious intervention or inadvertent errors, and
protect the privacy of users who are being sensed or sharing parts of their data.
These security issues are always a concern in shared systems and in most currently
deployed WSNs they are not considered because the access to the sensor measure-
ments is granted to a known and limited number of users. The security mechanisms
are especially beneficial for the end users and WSNs providers who will be keener
to share their measurements if the data are handled securely. As a result, more
services using WSNs would be developed and offered, which would be advanta-
geous for service providers and network operators.
The security enhancements provided by SNIF would enable the support of
accountability, access control, and billing methods. These features would facilitate
development of business models based on the WSNs and therefore more investors
would be interested in investing in WSN applications.
Another functionality of SNIF which will also contribute to the expansion of the
WSN market is a high-level query processing. Current WSN systems handle very
basic queries and because they are designed as vertical solutions, they are not able
to respond to complex queries which would require interaction with various hetero-
geneous WSNs. This feature would enable deployment of sophisticated, complex
applications and composed services.
A different feature of SNIF which would enable new applications is caching and
data history. Many end users will be interested not only in applications using current
and future measurements but also in applications which require sensor measure-
ments from the past. Most current WSN systems can respond to requests for mea-
surement of future events. The previously obtained sensor samples can only be
reused if the user explicitly requests to store them for a potential future application.
With SNIF, the WSN measurements can be shared among various applications.
Therefore, it is possible that the sensor measurements used for one service can be
requested in the future by another application. As a result SNIFs would allow service
providers to offer applications which require sensor data from the past.

5.2 Existing Integration Frameworks

5.2.1 Overview

5.2.1.1 Historic Perspective on Integration Frameworks Deployment

The research and development in WSNs was initially driven by defense applications.
Around 1980 the Defense Advanced Research Projects Agency (DARPA) started the
Distributed Sensor Networks (DSN) program in order to study whether the agency's