From vertical to horizontal architecture: a cross-layer implementation in a sensor network node

Some of the main challenges related to wireless sensor networks implementation are low-quality communication, energy conservation, resource-constrained computation, distributed network management, data processing and the scalability of the protocols. This combination makes the implementation of software a demanding task and encourages to new approaches when thinking of software architecture.In this paper an architecture combining a low protocol stack with a cross-layer management entity is presented. One of the main ideas behind the architecture presented is to make application programming easier and to simplify the protocol stack in such a way that it would suit better for the limited resources available. The role of the cross-layer management entity is to offer a shared data structure and to take care of some sensor network specific functions, like topology management and power saving. It also provides certain services that applications and the layers in the protocol stack can use.This architecture has been created specially for needs of wireless sensor networks implementation and the special attention has been paid to modularity and testability of implementation. An implementation based on this cross-layer architecture, CiNet, is also presented in this paper. The functionality of the architecture and the CiNet network was verified by using two different protocol stacks. Wireless communication of the network is based on the 802.15.4 technology.