In an era dominated by wireless connectivity, the NEXTT Testbed emerges as a groundbreaking platform that pushes the boundaries of research and innovation in next-generation wireless networks. Developed through collaboration between academia, industry, and local government, this city-wide testbed offers unparalleled capabilities for exploring dynamic spectrum access, vehicular communications, underground wireless systems, and radio frequency machine learning (RFML)
What is the NEXTT Testbed?
The NEXTT Testbed, also known as Cognitive Secure Cloud-Radio Access Network (CoSeC-RAN), is a state-of-the-art wireless experimentation platform deployed across 1.1 square miles of the University of Nebraska-Lincoln and public streets in Lincoln, Nebraska
Key Features:
- Wide Coverage: Five strategically located sites equipped with 4×4 MIMO SDR transceivers and connected via 20 Gbps fiber fronthaul network
- Underground Capabilities: Dedicated underground antennas enable wireless experiments below the surface
- High-Performance Computing: Cloud infrastructure with CPUs, GPUs, and FPGAs for real-time data processing
- Advanced Software Ecosystem: A user-friendly web portal supports scheduling, monitoring, and data retrieval
Why the NEXTT Testbed Matters?
Dynamic Spectrum Access (DSA)
With the rise of unlicensed spectrum use, DSA has become crucial to ensure fair and interference-free wireless communication. The NEXTT Testbed enables real-world DSA experiments to address spectrum pricing, quality of service, and policy challenges
Internet of Advanced Things
NEXTT bridges urban, rural, and underground connectivity gaps, supporting smart agriculture, infrastructure monitoring, and public safety
Machine Learning for Wireless Networks
By enabling RFML experiments, the testbed facilitates AI-driven optimizations, such as smarter spectrum usage and enhanced communication protocols
A Glimpse into the Architecture
1. Hardware Design
- SD-DU (Software-Defined Distribution Units): Equipped with USRP N310 transceivers and 4×4 MIMO antennas for sub-6 GHz frequencies
- Underground Antennas: Specialized 2×2 MIMO patch antennas for underground-to-aboveground communication
- Fiber-Optic Network: A high-speed fronthaul network offering 10 Gbps connectivity per SD-DU
2. Cloud Infrastructure
- Hosted by the Holland Computing Center (HCC), it offers massive computational power and data storage capabilities for both real-time and offline experiments
3. Software & User Workflow
- A web portal allows researchers to stage, monitor, and analyze experiments seamlessly
Real-World Applications and Experiments
1. Distributed Spectrum Sensing
The testbed allows simultaneous spectrum monitoring across all five sites, analyzing real-time radio activity for efficient spectrum usage
2. Underground-to-Aboveground Communication
Experiments demonstrate the feasibility and challenges of wireless communication between buried sensors and above-ground infrastructure
3. Vehicular-to-Infrastructure (V2I) Communication
Using vehicular antennas and roadside units, the testbed supports V2I experiments to enhance smart transportation systems
Scalability and Future Plans
The NEXTT Testbed is built for scalability. Plans include:
- Frequency Expansion: Integration of mmWave and Terahertz devices
- Spatial Expansion: Adding more SD-DUs across the city.
- Enhanced Licensing: Collaboration with the FCC to expand experimental frequency licenses.
Empowering Education and Research
Beyond cutting-edge research, the testbed serves as an educational tool, offering hands-on experience to students in wireless network principles, spectrum sensing, and RFML