Software Issues in Wireless Sensor Networks - Application and Multidisciplinary Aspects of Wireless Sensor Networks - page 41

3.2.2.4 Sun SPOTs/Squawk: A Conclusion

Sun SPOTs certainly provide an easier programming model and as a result they
are very popular within certain educational circles. However, their bulky size
(compared to TinyOS-based platforms), higher price (for noneducational use), and
higher battery consumption still make them somewhat impractical for some indus-
trial applications.

3.3 Spatial Programming - A Brief Overview

Recently, there has been a lot of research effort into programming paradigms for
spatial computing. These paradigms are applicable for sensor networks, as they too
consist of small computing devices distributed over a spatial area.
Typical challenges which a sensor network programmer faces in the traditional
programming model include:

• Inherent unreliability of both wireless sensor links (due to communication

interference and noise) and sensor nodes (due to depleting battery power)
Unsuitability of IP data-based addressing: geographical approaches allow for

•

easier replacing of spent nodes, as it is enough to move into physical space of the
malfunctioned node to continue receiving messages
Too much overhead in setting up and maintaining connections between communi •

cating sensor nodes
Resulting unscalability of solutions developed using the traditional program-

•

ming model

Spatial Programming paradigms attempt to address these issues using concepts
such as:

• Shared spatial variables , allowing programmers to read and write such
variables directly from their code, without the need to implement synchroniza-
tion and communication as they will be performed by the spatial programming
framework
• Location-based naming for individual computing devices in a spatial scenario,
instead of generic IP addresses
• Smart messages , through which both data, application state and code snippets
can be exchanged between computing devices
• Centralized programming , writing code which describes the behavior of spatial
application all in one place. Actual code snippets for execution on remote com-
puting devices will be sent through smart messages

Spatial computing is an emerging, highly active, interesting research area. For
more information and one example implementation, an interested reader can fol-
low [ 4, 5 ].