School of Information Science Japan Advanced Institute of Science and Technology Email: firstname.lastname@example.org
Hokuriku Research Center National Institute of Information and Communications Technology Email: email@example.com
School of Information Science Japan Advanced Institute of Science and Technology Email: firstname.lastname@example.org
Abstract—In this paper, we present AEROMAN (Architecture to Evaluate Routing PrOtocols for Multi-hop Ad-hoc Networks) which is designed and implemented for evaluation of routing protocols for multi-hop wireless networks. AEROMAN uses QOMET, a wireless link emulation tool, to compute parameters of wireless links, such as bandwidth, delay, packet loss rate, in contention-free conditions. In order to take into account the properties of contention-based media access for wireless channel, AEROMAN uses an Adaptive Trafﬁc (AT) model to emulate the sharing feature of CSMA/CA mechanism in IEEE 802.11. The evaluations show that the AEROMAN with AT model effectively captures the characteristics of wireless communications. Several experiments using OLSR as routing protocol with different routing metrics are performed in order to illustrate the main features and usability of AEROMAN. Index Terms—emulation, modeling, real-time, testbed, routing, wireless networks.
to support real-time evaluation of topology-related protocols. AEROMAN, which follows the distributed concept, is being developed at Hokuriku Research Center, National Institute of Information and Communications Technology, in Ishikawa, Japan. This architecture allows us to perform various realistic large-scale experiments with different wireless network technologies, such as WLAN and ZigBee, on a wired-network testbed. The contributions of this paper are as follows: •
I. I NTRODUCTION Recently, multi-hop wireless network has been introduced as a promising approach for next generation wireless networks to enable communication, even in the absence of infrastructure. However, before widely deploying multi-hop wireless networks, it is necessary to test the systems to verify their functionalities. Network emulation is an experimental technique bridging the gap between simulation and real-world experiments, and thus, it has signiﬁcant impact on the wireless research community. As in real-world testbeds, application testing can be run in real-time in a more realistic environment, for example, adhering to hardware speciﬁc limitations, using real protocol implementations, etc. Similar to simulation, the wireless medium effects can be controlled to re-enact network constellations. The only thing affecting the accuracy of the model is the ﬁdelity of the emulation layer control. Emulation experiments are more difﬁcult to set up than simulations because of the usage of real devices, but changing conditions is considerably easier than in real-world experiments. The switching process from emulation to real-world deployment is accelerated, since most part of the codes can be reused. Basically, emulation environments for multi-hop ad-hoc networks can be classiﬁed into two types: centralized emulator, and distributed emulator. Further discussions about each type are presented in Section V. Only distributed emulators are able •
We present a novel architecture (Section II) to perform experiments for evaluating wireless multi-hop routing protocols. A model, named Adaptive Trafﬁc (AT) model in Section III, is proposed to effectively capture the properties of contention-based media access for wireless channel. This model is used by a module of AEROMAN. Using the proposed architecture, we perform several experiments with different routing metrics, such as ETX (Expected Transmission Count)  and ETT (Expected Transmission Time) , running on OLSR (Optimized Link State Routing Protocol) . II. AEROMAN
AEROMAN is a...