NT-SIM: A co-simulator for networked signal processing applications.

In networked signal processing systems, network nodes that perform embedded processing on sensory inputs and other data interact across wired or wireless communication networks. In such applications, the processing on individual network nodes can be described in terms of dataflow graphs. However, to analyze the correctness and performance of these applications, designers must understand the interactions across these individual "node-level" dataflow graphs - as they communicate across the network - in addition to the characteristics of the individual graphs. In this paper, we develop a new simulation environment, called the NS-2 - TDIF SIMulation environment (NT-SIM) - that provides integrated co-simulation of networked signal processing systems. NT-SIM systematically combines the network analysis capabilities provided by the Network Simulator (ns) with the scheduling capabilities of a dataflow-based framework, thereby providing novel features for more comprehensive simulation of networked signal processing systems. Through a novel integration of tools for network and dataflow graph simulation, our NT-SIM environment allows comprehensive simulation and analysis of networked signal processing systems. We present a case study that concretely demonstrates the utility of NT-SIM in the context of a heterogeneous signal processing system design.