The 3rd Generation Partnership Project (3GPP)
Release 15 introduced 5G technology, offering significant operational advantages for military communications. However, its
radio access technology, 5G New Radio (NR), remains vulnerable
to a range of threats. The Multi-Access (MA) connectivity feature
enables 5G services over both 5G NR and non-3GPP access
networks. In Release 16, MA connectivity is enhanced through
Access Traffic Steering, Switching, and Splitting (ATSSS), ensuring seamless service continuity across heterogeneous networks.
Recognizing MA connectivity as a mitigation measure, this paper
presents a standards-compliant, open-source implementation of
ATSSS using Multipath TCP (MPTCP) in an MA 5G system
integrating tactical radios as non-3GPP access alongside 5G NR.
Validation using over-the-air 5G NR and L3Harris AN/PRC152A tactical radios demonstrates seamless failover and load
balancing, confirming the operational relevance of MPTCP-based
ATSSS for military applications.
This paper was originally presented at the International Conference on Military Communication and Information Systems
(ICMCIS), organized by the Information Systems Technology
(IST) Scientific and Technical Committee, IST-224-RSY – the
ICMCIS, held in Bath, United Kingdom, 12-13 May 2026.