EMPOWER: a network emulator for wireline and wireless networks

The increasing need of protocol development environments and network performance evaluation tools gives rise to the research of flexible, scalable, and accurate network emulators. The desired network emulator should be able to facilitate the emulation of either wireline or wireless networks. In the case when network topology is critical to the underlying network protocol, the emulator should provide specific mechanisms to emulate network topology. In this paper, we present a distributed network emulation system EMPOWER, which not only can fulfill those requirements, but also can generate user-defined network conditions and traffic dynamics at packet level. EMPOWER is highly scalable in that each emulator node could be configured to emulate multiple network nodes. Some significant research issues such as topology mapping scheme and scalability of the emulator are discussed and addressed. Preliminary emulation results show that EMPOWER is capable of assisting the study of both wireless and wireline network protocols and applications.

I. Introduction

Network emulation and simulation are widely used to develop, test, and debug new protocols, to explore and study a specific network-related research issue, or to evaluate the performance of an existing protocol or a scheme. Network simulators such as ns [1] generally provide a rich set of protocol modules and configuration tools that can be easily used to conduct customized simulation experiments. However, the functionalities provided by those supported modules in network simulators are merely logical operations rather than real implementations. Thus a protocol implementation in a network simulator must be modified before being deployed to a target network. Moreover, network simulation will consume a large amount of time when the simulated network is sufficiently large.