Real and Virtual Wireless Radio Network Emulator Matthew Dillon 1 , Er-Hsien (Frank) Fu 2 , Daniel Gdula 2 , Trang Mai 1 , Joseph Molnar 1 , and Lan Tran 1 1 Networks and Communications Systems Branch, Naval Research Laboratory, Washington, DC 20375 2 KEYW Corporation, Hanover MD, USA Abstract—In this paper, we discuss the use of the RF Wireless Network Environment emulator. Its architecture and capabilities are investigated. Four case studies of the RF network emulator are presented in this paper. The first case study simulates the slow-hopping anti-jamming waveform. The second case study is the application of spectrum masking, the third is the use of power difference of arrival localization algorithm to triangulate the location of a local unknown emitter and the fourth utilizes the emulator for testing and verification of a Multiple Link Common Data Link System. The network architecture and setup of the environment emulator for each case is discussed in detail. I. I NTRODUCTION When testing and implementing RF communications and wireless networks, it is often useful to have the ability to observe particular environmental effects on a network in a controlled environment in order to identify particular chan- nel properties that affect the communications network. The RFnest TM , developed by Intelligent Automation Inc. (IAI) consists of an RF environment emulator that is useful for replicating channel effects similar to those that are observed in the implementation of a full-scale field test. There are significant advantages to having the ability to conduct field tests in a testbed that emulates the physical properties of the environment, including: repeatability, realism, and cost. Implementing real field tests is significantly more expensive and it is difficult to replicate and repeat similar channel conditions and scenarios in a physical environment. The RF Wireless Network Environment Emulator (RFWNEE) has the capability to emulate real life wireless channels to evaluate wireless radio networks in a laboratory environment with high fidelity. The RFWNEE can produce and host a wireless network environment with wireless channel properties, such as range attenuation, range delay, multipath, Doppler effect and interferences. The RFWNEE also provides a capability for examining network scaling effects by allowing communications between real and virtual radios. Virtual radio nodes are emulated by the Naval Research Laboratory's (NRL) Extendable Mobile Ad-hoc Network Emulator (EMANE) [1] [2]. Communications between real and virtual radios are accomplished through a Surrogate Virtual Receiver/Surrogate Virtual Transmitter (SVR/SVT) [1]. In this paper, we discuss the architecture of the RFNWEE and four case studies examined are implemented with the de- tails, simulation setup and results for each. Brief descriptions of the case studies are listed as follows: - slow-hopping anti-jam waveform (SHAW): an inter- ference source is added and the SHAW waveform is simulated over a channel for both static and dynamic scenarios - spectrum masking: the doppler shift and delay function of the RFnest is utilized in order to emulate the latency of the signal - emitter localization: a local unknown emitter's position is triangulated by a mesh sensor network using power difference of arrival (PDOA) - Multiple Link CDL System Testing: software and hardware development testing is recursive, and use of the RFNWEE is used to test a Multiple Link Common Data Link System (MLCS) to configure and operate various software and hardware interfaces II. RF WIRELESS NETWORK ENVIRONMENT EMULATOR ARCHITECTURE Currently the RFWNEE has an operating band of [20 MHz - 6 GHz] with linearity optimized for the [20 MHz - 3 GHz] band, a dynamic range of 60 dB per channel, a maximum propagation delay of 2 sec, a maximum multipath tap per channel of 20, a Doppler shift of 200 kHz per path and various fading profiles such as frequency selective, frequency flat fading, Rayleigh, Rician, pure Doppler, frequency shift, phase shift and log-normal. The emulator supports a variety of network configurations such as SISO, MIMO, MISO, SIMO, and fully meshed. The main component of the RFWNEE is IAI's RFnest TM D512 RF channel emulator. With the D512 emulator, the current set up can support a meshed network of twelve nodes and the network size is expandable. As it is depicted in Fig. (1), the radio under test (RUT) is interfaced with the D512 through the RF daughter board (RFDB), which is responsible for conversion between RF and IF bands for transmitted and received signals. The digital daughter board (DDB) interfaces with the RFDB and the main FPGA board and it has high speed ADCs and DACs for conversion between analog and digital domain. In addition, each DDB has a mid-size FPGA, which is used for signal multiplexing in order to maximize the transmission capacity between the DDB and the main FPGA. The main FPGA is the RF channel emulation engine and it is capable of supporting up to a 48 node full meshed network in half-duplex mode. The expansion board allows the D512 chassis to be expaded and multiple chassis can be joined Milcom 2016 Track 2 - Networking Protocols and Performance U.S. Government work not protected by U.S. copyright