[Tinyos] Viptos 5.1-alpha release available

[Elaine Cheong]

We are announcing the first alpha release of Viptos (Visual Ptolemy and 
TinyOS), an integrated graphical development and simulation environment 
for TinyOS-based wireless sensor networks.

Please visit the website at:
http://ptolemy.eecs.berkeley.edu/viptos

Full abstract:

Viptos (Visual Ptolemy and TinyOS) is an integrated graphical development 
and simulation environment for TinyOS-based wireless sensor networks. 
Viptos allows developers to create block and arrow diagrams to construct 
TinyOS programs from any standard library of nesC/TinyOS components. The 
tool automatically transforms the diagram into a nesC program that can be 
compiled and downloaded from within the graphical environment onto any 
TinyOS-supported target hardware. In particular, Viptos includes the full 
capabilities of VisualSense, which can model communication channels, 
networks, and non-TinyOS nodes. This release of Viptos is compatible with 
nesC 1.2 and includes tools to harvest existing TinyOS components and 
applications and convert them into a format that can be displayed as block 
(and arrow) diagrams and simulated.

Viptos is based on TOSSIM and Ptolemy II. TOSSIM is an interrupt-level 
simulator for TinyOS programs. It runs actual TinyOS code but provides 
software replacements for the simulated hardware and models network 
interaction at the bit or packet level. Ptolemy II is a graphical software 
system for modeling, simulation, and design of concurrent, real-time, 
embedded systems. Ptolemy II focuses on assembly of concurrent components 
with well-defined models of computation that govern the interaction 
between components. VisualSense is a Ptolemy II environment for modeling 
and simulation of wireless sensor networks at the network level.

Viptos provides a bridge between VisualSense and TOSSIM by providing 
interrupt-level simulation of actual TinyOS programs, with packet-level 
simulation of the network, while allowing the developer to use other 
models of computation available in Ptolemy II for modeling various parts 
of the system. While TOSSIM only allows simulation of homogeneous networks 
where each node runs the same program, Viptos supports simulation of 
heterogeneous networks where each node may run a different program. Viptos 
simulations may also include non-TinyOS-based wireless nodes. The 
developer can easily switch to different channel models and change other 
parts of the simulated environment, such as creating models to generate 
simulated traffic on the wireless network.

Viptos inherits the actor-oriented modeling environment of Ptolemy II, 
which allows the developer to use different models of computation at each 
level of simulation. At the lowest level, Viptos uses the discrete-event 
scheduler of TOSSIM to model the interaction between the CPU and TinyOS 
code that runs on it. At the next highest level, Viptos uses the 
discrete-event scheduler of Ptolemy II to model interaction with mote 
hardware, such as the radio and sensors. This level is then embedded 
within VisualSense to allow modeling of the wireless channels to simulate 
packet loss, corruption, delay, etc. The user can also model and simulate 
other aspects of the physical environment including those detected by the 
sensors (e.g., light, temperature, etc.), terrain, etc.

Elaine Cheong