# WISCANet: A Rapid Development Platform for Beyond 5G and 6G Radio System Prototyping
## 1 Introduction  
The fifth generation (5G) of wireless communications systems has quickly become a global industry standard. To address the growing list of requirements not satisfied by the existing 5G New Radio (NR) standards, academia and industry have shifted their focus to beyond-5G (B5G) and 6G systems. Several reputable agencies have established organizations to address this problem, including: _Technologies for Network 2030_ initiated by the International Telecommunication Union (ITU) in July 2018 [1]; _6G Vision and Drivers_ launched by Generation Mobile Networks (NGMN) in 2020 [2]; and a group of projects referred to as ICT-20 _5G Long Term Evolution_ and ICT-52 _Smart Connectivity beyond 5G_ initiated by the European Commission in 2020. The United States, China, Germany, Japan, and South Korea have all published plans to pursue 6G research [3].  
To augment the capabilities of 5G systems, multi-function systems simultaneously integrate multiple wireless functionalities, including sensing, communications, computations, and controls [4; 5; 6; 7]. These hybrid technologies enable mutual performance enhancements and novel capabilities, but also demand higher computational complexity and more capable RF front-ends (RFFEs) [8; 9]. Several emerging solutions significantly mitigate these hardware and software limitations, including domain-specific heterogeneous processors [10; 11; 12]; multi-access techniques and hybrid processing architectures [13; 14; 15; 16]; machine learning (ML)and artificial intelligence (AI) techniques [17, 18, 19, 20, 21]; and reconfigurable intelligent surfaces (RISs) [22, 23, 24].  
Despite the incredible capabilities of these emerging technologies, implementing and validating functional prototypes is still a tedious and time-consuming challenge. SDRs [25, 26, 27] and RF system-on-chips (RFSoCs) [28, 29] have greatly simplified this process, but still require some expertise to use efficiently.  
To accelerate the implementation and validation of numerous B5G/6G applications, we developed the WISCA Software-Defined Radio Network (WISCANet) [27, 30]. WISCANet is a hardware-agnostic control software that automatically configures and controls a software-defined radio (SDR) network. By abstracting the hardware controls away from the user, WISCANet allows a non-expert user to deploy an over-the-air (OTA) application by simply defining a baseband processing chain in a high level language. WISCANet emulates real-time operations, allowing users to perform real-time experiments without the typical restrictions on processing speed and hardware capabilities. By abstracting the hardware controls and emulating real-time operations, WISCANet allows end-users to quickly deploy radio applications without becoming hardware experts or rigorously optimizing their software. To further improve portability, accessibility, and ease-of-use, we continue to expand the supported hardware and programming languages (MATLAB, Python, C/C++, Rust, Julia, etc.). This architecture is depicted in Figure 1.  
To support higher frequency ranges, WISCANet deployments may be augmented by either mixing directly from baseband or superheterodyning inside the equipped RFFEs. In our specific deployment (pictured in Figure 2), we have executed over-the-air applications as high as 71 GHz. To support 6G research, we plan to extend support into the THz band; unfortunately, commercial THz SDRs are not widely available, so we are actively pursuing a superheterodyning approach similar to the technique discussed later in this paper. Other researchers have successfully built small-scale THz test systems using the same strategy [31].  
Figure 1: The WISCANet control software runs on a control computer, which receives a user-defined application and automatically configures the connected edge nodes and radio to execute it. This allows users to deploy over-the-air radio applications without programming the radios themselves, which reduces development time and makes experimentation more accessible to beginners.