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Stroubles Creek CBRS Testbed Site

The transition from in lab to in the field experimentation and testing is driving demand for a more realistic and uncontrollable environment to assess more deeply the behavior, performance and resilience of  wireless systems and  their components.

The CCI xG Testbed Team has been deploying an outdoor environment to conduct experimentation and testing. It involves the construction of a Citizens Broadband Radio Service (CBRS)  private network using Virginia Tech Priority Access License (PAL).

Researchers in the CCI network can get access to our outdoor testbed to conduct their studies.

CBRS (the 3.5 GHz band, referred to as the 3550-3700 MHz band),  designed to promote shared band usage through a spectrum access system (SAS), features three tiers of access and authorization:

  • Incumbent access.
  • Priority access license (PAL).
  • General authorized access (GAA). 

The Stroubles Creek outdoor testbed that's under construction in Blackburgs, Va., an outdoor component of CCI’s xG testbed at the Arlington, Va., site,  is composed of two networks.

A production network (or CBRS private network) that contains a commercial core, three Citizens Broadband Radio Service Device (CBSD)s orchestrated by the FederatedWireless Spectrum Access System (SAS) to immediately support university use cases and to generate real datasets.

An experimental network consisting of an open-source core, three software-defined radio (SDR)-based 5G CBSD prototypes built in the lab and an open-source SAS “OpenSAS”. It will allow researchers to customize, reconfigure, and control software and hardware parameters, develop algorithms, and improve performance and efficiency. For the first time experimenters can perform end-to-end CBRS experimentation.

Stroubles Creek overview
Stroubles Creek, approximately 12 miles long, runs through Blacksburg, the Virginia Tech campus, and Montgomery County, Virginia.

The outdoor testbed site cover a 1.5 miles corridor with three roof-top locations. The CBSD node locations are as shown in the map snippet:

  • CBSD1: Human and Agricultural Biosciences Building rooftop.
  • CBSD 2: Hahn Hall North rooftop.
  • CBSD 3: The Animal husbandry Barn.
Map showing CBSD locations at Stroubles Creek facility on Virginia Tech Campus in Blacksburg

CBSD (5G NR standalone network in CBRS band)

The Experimental CBSD are deployed using USRP x310, we are using srsRAN 5G NR stack and Open5GS core network for the 5G NR standalone CBRS network deployment.

We used Intel NUC to host Core and RAN software. We have integrated a Commscope commercial CBRS Antenna. These equipment will be put in weatherproof enclosures equipped with PiKVM and Ethernet PDU to remotely monitor and control the devices.

experimental CBSD prototype at Stroubles Creek facility on Virginia Tech Campus in Blacksburg

Virginia Tech Priority Access License (PAL)

The planned deployment will also include commercial CBRS base stations that are part of the non-experimental or production deployment. 

The Virginia Tech Foundation has acquired Priority Access Licenses (PALs) for the newly available Citizens Broadband Radio Service (CBRS). Virginia Tech’s priority access licenses include four 10-MHz blocks in Montgomery County and another four 10-MHz blocks in Craig County. The licenses are held by Virginia Tech Technology Assets (VTTA), a subsidiary of the Virginia Tech Foundation, and will be administered by the Division of Information Technology.

Map showing Virginia Tech Priority Licenses
CCI grad assistants at Stroubles Creek
CCI graduate research assistants Asheesh Tripathi, left, and Oren Collaco, collect data to deploy a private mobile network near Stroubles Creek on Virginia Tech’s Blacksburg campus. The system, based on Citizens Broadband Radio Service (CBRS), allows researchers to use the CCI xG Testbed to test wireless solutions for mobile networks and leverage spectrum sharing research. Here, a commercial-grade CBRS antenna, enclosed in a white weatherproof plastic tube, is connected to a spectrum analyzer.