JMA Wireless, Amazon Web Services (AWS) and Crown Castle have completed a private LTE network deployment for Carnegie Mellon University using Citizens Broadband Radio Service (CBRS) spectrum.
Plans for the project started in mid-2020, as CMU looked to upgrade cellular connectivity to support research at its Living Edge Lab on campus. Before embarking on the recent LTE upgrade, the university was already using a 4G private wireless network with a Band 42 3.5 GHz experimental license.
Prior to that it relied on controlled wired and Wi-Fi environments in the edge compute-focused research lab for applications that needed latency as low as 10 ms.
The CBRS network took less than three months to construct and commission, and first went live this summer in June. JMA and AWS teamed up to design and help build the network, which uses JMA’s XRAN virtualized RAN software with a Druid Software core running on AWS Snowball Edge. JMA outdoor CBRS radios were installed on campus alongside the vendor’s directional CBRS antennas deployed by Crown Castle.
The purpose is to power research in the Living Edge Lab, led by edge compute expert Professor Mahadev Satyanarayanan’s research team, and the network covers multiple areas – including most of the CMU campus, a public park location called Schenley Plaza and a downtown shopping district.
It's currently an outdoor only network and uses general authorized access (GAA) CBRS spectrum, according to Bill Plummer, SVP of Communications at JMA Wireless.
“We are delighted to see the performance and power of the virtualized wireless system put in place here at CMU,” said Professor Satya in a statement. “We now have the most state-of-the-art wireless technology in the industry right here where we do cutting-edge research.”
The ability to utilize CBRS spectrum via unlicensed general authorized access (GAA) helped initiate the upgrade plans. A July blog by Jim Blakley, Living Edge Lab Associate Director, explained how the earlier LTE network, which consisted of three outdoor sites and was built in 2017 with Crown Castle and DT, delivered better latency than carriers could provide but was limited by coverage and a lack of commercially available devices at the time.
Since then, the Federal Communications Commission (FCC) opened up access to 3.5 GHz frequencies in the shared CBRS band through priority access licenses (PALs) and GAA use. Federated Wireless is providing the spectrum access system (SAS) for CMU’s network. The SAS manages spectrum sharing in the CBRS band and providers are authorized by the FCC.
In addition to spectrum, “commercial 4G LTE network and user equipment for this frequency band was increasingly available,” wrote Blakely. “We began a plan with our partners to upgrade the existing network to a modern, supportable network in the CBRS band, covering a broader geographic area with lower latency and greater throughput.”
There are four outdoor sites using JMA CBRS Cell Hubs. The JMA vRAN operates on a commercial off-the-shelf server and wireless evolved packet core (deployed on AWS Snowball) are in the Living Edge Lab data center and connected by a Crown Castle fiber network.
As of late July, the network was providing latencies between 30-35 ms, with download throughput between 60-80 Mbps and upload of 15-25 Mbps.
Plans to further reduce latency include upgrading the RAN and core to 5G, although the CMU lab said it’s exploring other options as well.
"This is another industry-forging deployment in our growing relationship with JMA, and a testament to the strength of our ongoing collaboration,” said Robin Harwani, head of Global Telecom Industry Solutions at AWS, in a statement “Customers at universities globally have asked for private 4G and 5G reference architecture for technology research in 5G and for better connectivity on their campuses, and we are excited that this solution is designed to help achieve this objective.”
JMA and AWS have partnered on private networks using CBRS before, including trials in California school districts this summer as part of an effort to tackle the digital divide. That collaboration also involves Intel, CommScope and Megh Computing.
Universities and carriers are teaming up on private wireless as well. The University of Tennessee and AT&T have plans for private 5G network testbed using millimeter spectrum on campus this fall to explore 5G use cases and digital learning.