The B5G Athens Experimentation Platform
H. Koumaras, D. Fragkos, V. Pitsilis,
G. Makropoulos
NCSR DEMOKRITOS
Agia Paraskevi, Greece
{koumaras, dfragkos, vpitsilis,
gmakropoulos}@iit.demokritos.gr
G. Lyberopoulos,
E. Theodoropoulou, F. Setaki,
I. Mesogiti, D. Diakakis
OTE, Athens, Greece
{glimperop, etheodorop, fsetaki,
imesogiti, d.diakakis}@ote.gr
Abstract- The Beyond 5G (B5G) Athens platform, a state-ofthe-art large scale facility for Standalone (SA) network
experimentation, spanning in aera the NCSR Demokritos and
COSMOTE/OTE Academy campuses in Athens. The two sites
are interconnected at control and data plane level by utilizing a
dedicated 10G dark fiber link. Two radio access networks are
offered, each linked to separate 5G core implementations,
allowing the study of inter-PLMN handovers and roaming
scenarios, but also Multi-Operator Core Network (MOCN)
configurations.
Keywords—6G;
Experimentation.
5G;
Platform;
Testbed;
Athens;
NTN;
I. INTRODUCTION
The B5G Athens Experimentation Platform is an advanced
large-scale 5G SA experimental facility, which is spread
across two different locations at the metropolitan region of
Athens in Greece, namely the COSMOTE/OTE Academy
campus in Marousi and the NCSR Demokritos campus in
Aghia Paraskevi. Both sites are interconnected at control and
data plane level with a dedicated 10G dark fiber, operating two
fully operational 5G SA networks with MOCN capabilities.
N. Gkatzios, C. Fragkos,
V. Koumaras
INFOLYSIS P.C.
Athens, Greece
{ngkatzios, cfragkos,
vkoumaras}@infolysis.gr
NCSR Demokritos campus. Each of these two BBUs controls
three Ericsson Remote Radio Units (RRU) at each domain,
therefore realizing a large scale private 5G SA network with
six indoor/outdoor cells/Radio Access Network (RAN) units in
total for both sites. The latter 5G SA network is deployed
exclusively at NCSR Demokritos campus and is based on
Amarisoft 5G RAN and a variety of 5G SA Core
implementations, such as Amarisoft, Open5GS and free5GC,
which are supporting different levels of openness (e.g.,
NEF/CAPIF) [1]. Thus, the NCSRD campus site includes two
radio access networks that are connected to different 5G cores,
with this setup enabling further research in inter-PLMN
handover and roaming scenarios. One potential scenario for
the realization of the inter-PLMN capabilities of the platform
according to the aforementioned topology, could be a User
Equipment (UE) moving from the coverage area of one Public
Land Mobile Network (PLMN) to another PLMN, while
maintaining its ongoing session, from Operator A (e.g.,
COSMOTE) to Operator B (e.g., NCSRD). Additionally, due
to this variety of RAN and core technologies, recently the
platform features also MOCN capabilities, expanding further
the supported types of experiments.
Additionally, the platform features a satellite/NTN emulator
allowing the low-cost, agile multi-operator and multi-access
experimentation. The emulated satellite network is based on
the OpenSAND tool and consists of three key components: the
satellite gateway, the satellite, and the satellite terminal. In a
multi-connectivity scenario, Access Traffic SteeringSwitching-Splitting
(ATSSS)
enables
the
efficient
employment of multiple Radio Access Technologies (RATs),
while Multi Path TCP (MPTCP) combines numerous network
pathways into a single TCP connection, enhancing QoS for
users with hybrid access.
II. SUPPORTED CORE NETWORK TECHNOLOGIES
Fig. 1. The B5G Athens Experimentation Platform
The first 5G SA network is based on Athonet 5G SA Core
and Ericsson Baseband Units (BBU)/Remote Radio Unit
(RRU)/RAN, being deployed both at the COSMOTE and
NCSR Demokritos campuses. More specifically, the
ATHONET 5G Core, located in COSMOTE/OTE Academy
premises, controls two Ericsson Baseband Unit (BBU) units,
one deployed at COSMOTE campus and one deployed at
As far as the Core Networks are concerned, the supported
options are as follows:
• Amarisoft 5G SA Core: The Amarisoft 5G Core
network solution provides essential network functions for the
operation of a 5G network, Access and Mobility Management
Function (AMF), Authentication Server Function (AUSF),
Session Management Function (SMF), User plane Function
(UPF), UDM (Unified Data Management), and 5G Equipment
Identity Register (5G-EIR) all integrated within the same
software component.
• Athonet 5G SA Core: ATHONET 5G Stand Alone
(SA) core network includes two UPFs (User Plane Function)
to emulate the edge and core 5G network data plane. This
setup is hosted at COSMOTE Cloud facilities, providing a
secure and reliable infrastructure.
• Open5GS/Free5GC: The Athens platform has adopted
the cloud-native paradigm by utilizing containerized
implementations for its 5G core network components.
Therefore, it employs Open5GS, which breaks down the 5GC
into microservices-based containers (e.g., AMF, UPF, NRF),
each with its own dependencies and signaling. Additionally, it
incorporates Free5GC, which supports Network Data
Analytics Functions (NWDAF) such as AnLF and MTLF and
exposes a subset of 3GPP-compliant NWDAF APIs (e.g.,
WLan_Performance, NF_Load, NSI_Load_Level)
III.
SUPPORTED RAN TECHNOLOGIES
The RAN is based on the Ericsson BBU 6630 which is a
baseband unit that provides high-performance connectivity for
mobile networks. The unit is compatible with various radio
units, including the 4408, which is designed to provide highcapacity and low-latency connectivity for outdoor
deployments. In addition to the radio unit, the system also
includes the Indoor Radio Unit (IRU) 8848 and Dot 4479
B78L, which are essential components for the indoor
deployment of a 5G network. Together, these components
form a powerful and reliable radio access network that delivers
high-speed connectivity and low latency. In addition, Nokia
Airscale and 5G Small Cell deployments are also supported.
At the NCSRD site, the Amarisoft 5G NR which is also
supported, can operate in Frequency Division Duplex
(FDD)/Time Division Duplex (TDD) frequency bands below 6
GHz with up to 50 MHz of bandwidth. It supports various
subcarrier spacing options for both data and synchronization
signals and can operate in Multiple Input Multiple Output
(MIMO) configurations up to 4x4 in Downlink (DL).
Additionally, the softwarised RAN solutions that can be
connected to the containerized Open5GS include:
UERANSIM (both monolithic and containerized) srsRAN
(srsRAN gNB with srsUE over ZeroMQ-based setup).
IV.
set of KPIs or KVIs. Scenarios are a guideline for the
configuration of the network conditions to be present during
the execution of an experiment. For example, a Test Case may
be executed multiple times under different conditions, such as
low or high coverage, different network congestion, with UEs
in a static position or under different mobility patterns, etc.
The scenario includes information which is related to
network, service and environment configurations and it is
specific to the selected technologies and the target system. It is
also expected that results and measurements provided to
experimenters include a description of the effective scenario
(e.g., network configuration over time, allocated resources)
and records of all events (such as modifications to the Trial
Network’s description or status, whether initiated by
experimenters or automatically by the testbed or AI modules)
that could impact the KPIs.
Slices (or Trial Network) define the end-to-end resources
allocated for executing an experiment, including the
computational capability reserved to each component, as well
as the resources reserved in the emulated or real network made
available to the experimenter. Resources reserved in
virtualized environments to instantiate components of the Trial
Network will be reserved and dedicated to this trial network
exclusively, until the trial network is suspended or deleted.
Therefore, having dedicated resources allocated to trial
networks will ensure that KPIs and KVIs calculated during the
experiment are not affected by other trial networks activity.
Experiments are executed inside a Trial Network, where a
set of tools has been automatically deployed and configured
during the provisioning phase. Each experiment description
must include combinations of at least the following mandatory
fields: test cases, scenarios, and slices.
ACKNOWLEDGMENT
The work presented in this paper is supported by i) the
SUNRISE-6G project that has received funding from the Smart
Networks and Services Joint Undertaking (SNS JU) under the
European Union’s Horizon Europe research and innovation
programme under Grant Agreement No 101139257, and ii) the
6G-SANDBOX project that has received funding from the
SNS JU under the EU’s Horizon Europe research and
innovation programme under Grant Agreement No 101096328.
EXPERIMENTATION METHODOLOGY
The default experimentation methodology in Athens Platform
is based on the methodology defined as a result of the
5GENESIS Project [2]. This methodology [3] is based on the
definition of specific fields linked in a modular approach.
(Test Case description, Scenario identification, Slice templates
and Experiment description,). These components can be
combined in various ways to define a particular Experiment.
Test Cases are documents, usually following a pre-defined
template, that describe the general goals and the configurations
of the experimentation infrastructure the acquiring of a certain
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