On Communication Reliability of General Authorized Access Device on
Citizens Broadband Radio Service
Abstract
In 2015, the Federal Communications Commission approved the usage of
the 3.55 GHz - 3.70 GHz (i.e., band~48) spectrum
opportunistically for commercial purposes. Since then, the 150 MHz
bandwidth, also known as the Citizens Broadband Radio Service (CBRS),
has attracted the attention of the leading telecommunication industries
and the research communities. The CBRS spectrum has a hierarchical
access architecture where the original owners of the CBRS spectrum,
i.e., the incumbents, have the highest and uninterrupted transmission
authority. As the incumbent transmission is sparse, the unused spectrum
is opportunistically shared between the Primary Access License (PAL)
users and the General Authorized Access (GAA) users. Both the user
groups get approval to communicate on the CBRS spectrum from the
Spectrum Access System (SAS), which acts as a cloud-based centralized
administrator of the CBRS and is responsible for ensuring
non-compromised incumbent operation on the CBRS. Note that the GAA users
do not purchase the spectrum access through auction as PAL does and has
the slightest preference to communicate on the CBRS. In this paper, we
study the communication reliability of a GAA CBRS Device (GAA CBSD) when
the approval from the SAS administrator to communicate on the CBRS
spectrum is considered. Our experimental observations show that the
deployed GAA CBSD remains uncommunicative for a sizable amount of the
observed time duration as the SAS administrator does not allow the GAA
CBSD to communicate on the CBRS to protect the incumbent/PAL
transmissions.