Overview

TinyOS 2.x supplies a well-designed single hop messaging layer for applications, but there is no standardized multihop framework. To address this issue, we surveyed a large number of applications [1] to determine the addressing techniques and messaging stack features used in sensor networks. From the results of this survey, we designed a multihop networking API [2] to address the needs of application designers at the messaging layer in a unified way.

This framework intends to implement that API. The key goals of this include:

• Multihop routing with several addressing modes based on:
  • Node address (single node, multiple nodes, or a list of nodes)
  • Geographical region
  • Device hierarchy
• Intercept messages to be forwarded
• Control transmission effort
• Congestion management
• Support self-organized device hierarchies

Our design allows application designers to focus on the application layer without being bogged down by the details of routing protocol implementation. Similarly, routing protocol designers can make their improvements more accessible to the rest of the community since only a few wiring changes are needed to alter the routing protocol used by a given addressing mode, leaving application code untouched.

In its current form, the framework implementation supports addressing and multihop routing by a single node address. Our version of Dynamic Source Routing (DSR) [3] modified for TinyOS is used as the routing layer.

Code and Documentation

• Fundamentals - describes framework goals and overall structure
• Installation - guide to getting started with the framework
• Application Examples - demo applications that use the framework
• Framework Extension Examples - skeleton protocols that can be used as building blocks to expand the framework
• Source Code
• Source Code Documentation - generated from the framework code with nesdoc

References