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5G-MAG Reference Tools, Putting 5G in Action for Media

Authors:
  • Fraunhofer FOKUS

Abstract and Figures

Content providers are increasingly using the Internet to deliver media content to users. The same applies to users who are able to enjoy media on a wide variety of devices anywhere and at any time. The increasing consumption of high-quality mobile video over 5G networks demands highly-scalable, sophisticated and robust delivery architectures, systems and protocols ready to cope with different traffic loads and meet requirements and expectations from content owners. 5G is an opportunity to provide the media industry with a set of different tools to operate an advanced media delivery platform. With this in mind, 5G-MAG kickstarted the 5G-MAG Reference Tools project to develop common open-source reference tools to support implementation and interoperability of 5G-based media technologies. In this paper, we present the current architecture of the 5G-MAG Reference Tools implementing client components in the context of 3GPP Release 16 5G Media Streaming and 5G Broadcast. Moreover, we provide detailed insights on the first two target use-cases, (i) "LTE-based 5G Broadcast" and (ii) "broadband-broadcast seamless switching". An outlook on future work on targeting use cases such as "targeted ad-insertion" and "regional content insertion" is given. We also show how the tools serve as a reference or integration platform for traditional broadcast networks and services including a DVB-I service layer or the alignment with the service layer of ATSC3.0.
Content may be subject to copyright.
This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.
5G-MAG Reference Tools, putting 5G in action for media
Daniel Silhavy
Fraunhof er FOKUS
Berlin, Germany
daniel.silhavy@fokus.fraunhofer.de
Klaus Kühnhammer
Bitstem GmbH
Hausleiten, Austria
klaus@bitstem.com
Johann Mika
Austrian Broadcasting
Services
Vienna, Austria
johann.mika@ors.at
Thomas Stockhammer
Qualcomm
Munich, Germany
tsto@qti.qualcomm.com
Jordi J. Gimenez
5G-MAG
Geneve, Switzerland
gimenez@5g-mag.com
Abstract Content providers are increasingly using the Internet to deliver media content to users. The
same applies to users who are able to enjoy media on a wide variety of devices anywhere and at any
time. The increasing consumption of high-quality mobile video over 5G networks demands highly-
scalable, sophisticated and robust delivery architectures, systems and protocols ready to cope with
different traffic loads and meet requirements and expectations from content owners. 5G is an
opportunity to provide the media industry with a set of different tools to operate an advanced media
delivery platform. With this in mind, 5G-MAG kickstarted the 5G-MAG Reference Tools project to
develop common open-source reference tools to support implementation and interoperability of 5G-
based media technologies.
In this paper, we present the current architecture of the 5G-MAG Reference Tools implementing client
components in the context of 3GPP Release 16 5G Media Streaming and 5G Broadcast. Moreover, we
provide detailed insights on the first two target use-cases, (i) “LTE-based 5G Broadcast” and (ii)
“broadband-broadcast seamless switching”. An outlook on future work on targeting use cases such as
“targeted ad-insertion” and “regional content insertion” is given. We also show how the tools serve as a
reference or integration platform for traditional broadcast networks and services including a DVB-I
service layer or the alignment with the service layer of ATSC3.0.
Introduction
The Internet is now fully accessible to the media industry, and this creates tremendous opportunities for
new user service propositions, more personalized experiences, and a fast lane for innovation for
service providers and content creators. Within this developing ecosystem the combination of fixed and
wireless networks, as well as the global 5G introduction enables media content providers to have
access to a universal, ubiquitous, and future-proof distribution platform allowing them to reach users
everywhere, anytime and on any device - in particular the Gen-Z for which the smartphone is the
primary device for communication and entertainment [1]. The Ericsson Mobility Reports forecasts that
by 2027 5G networks will carry 62 percent of the world's smartphone traffic. Specifically, the delivery of
video content is expected to account for 79 percent of the mobile data traff ic in 2027 [2].
To support media and content providers in getting access to the powerful, but complex 5G distribution
platform, simplifications, support, and abstraction to the workflows of media providers are needed. In
the dynamic world of apps, software-centric solutions and agile developments, access to open-source
tools to support prototyping, trials and possibly even deployments are of utmost relevance. 5G-MAG
has taken on the duty and mandate to fill the role in bringing together the media and the 5G world to
support deployment of media services on 5G systems.
“This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.”
As a particular ef f ort to respond to the need of fast access to technology, the 5G-MAG Reference Tools
project
1
has been established. The overall goal of the project is to provide an end-to-end platform
enabling the implementation of media players as part of a 5G client; service layers and the testing of
applications developed by other media-related organizations; hybrid scenarios and integration of third-
party functions in the network.
In this paper, we present the current architecture of the 5G-MAG Reference Tools focusing on two main
initial uses cases. We illustrate the general working principles of the 5G-MAG Reference Tools focusing
on the main components “MBMS Modem”, “MBMS Middleware” and the “Webinterface”. We
demonstrate how to use the 5G-MAG Reference Tools to receive a 5G broadcast (5G BC) signal in
dedicated mode, i.e. using 100 % downlink capacity (also known as EnTV/FeMBMS in 3GPP Rel.14
and LTE-based 5G Terrestrial Broadcast in 3GPP Rel.16). The 5G broadcast signal contains File
Delivery over Unidirectional Transport (FLUTE) encoded DASH and HLS resources (the common
format is CMAF). These CMAF resources are processed and cached for DASH and/or HLS clients.
Using web-based players such as dash.js and hls.js the files received via 5G broadcast can be played
the same way as normal unicast broadband streams delivered via a CDN. This abstraction permits re-
use of existing apps and services independent of the delivery mode. Making use of the direct
integration of unicast and broadcast, we further enhance the implementation by dynamically and
seamlessly switching between broadcast and broadband content, referred to as “broadband-broadcast
seamless switching”.
5G Media Delivery
General
3GPP is defining core elements of the 5G system, including those that constitute the 5G media
distribution platform. Such standardization effort is leading to the support of different deployment and
collaboration among service providers, media companies and network operators to enable the creation
of new services and user experiences.
The first releases of 5G specifications, with Rel-16 completed in mid-2020, include the definition of the
5G Media Streaming architecture and LTE-based 5G Broadcast. 3GPP Rel-16 has been taken as the
starting point for the implementation of the 5G-MAG Reference Tools. Standardization continues in Rel-
17 and Rel-18 with several extensions to 5G media streaming, including edge capabilities, the
introduction of 5G Multicast Broadcast Services (5MBS) and the evolution of LTE-based 5G Broadcast,
among others.
5G Media Streaming
5G Media Streaming responds to the growing consumption of multimedia services, with video as its
maximum exponent, and the need to open the 5G System capabilities to content providers. A range of
collaboration models are enabled focused on improving QoE for end users, optimizing delivery across
the network, monetizing traffic or monitoring QoS and consumption.
The 5G Media Streaming architecture and basic procedures are specified in 3GPP TS 26.501 and
stage-3 specifications in TS 26.511 and TS 26.512 define a series of protocols, codecs and
functionalities well aligned with current over-the-top distribution models and applications [3].
The main components of 5G Media Streaming are the following:
- 5GMS Application Function (AF): provides management functions for the 5GMS system (control
plane), including provisioning and configuration (offered to the service provider) and reporting
(from the user equipment). Depending on the collaboration model, the 5GMS AF can be
deployed within the mobile network or in an external data Network (e.g. in the domain of the
service provider).
1
http s://www.5g -mag.com/reference-to ols
“This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.”
- 5GMS Application Server (AS): provides data and content functionalities (data plane) including
ingest functionalities (towards service providers) and the delivery to the 5GMS clients.
- 5GMS Client, containing the Media Session Handler (MSH), which receives the configuration
information from the AF and handles the relevant 5GMS features, and the Media Player which
obtains media content from the AS.
LTE-based 5G Broadcast
3GPP specified the first global broadcast standard to address 5G-enabled devices. LTE-based 5G
broadcast, widely known as 5G Broadcast, allows linear TV and radio to be broadcast to compatible
3GPP-based devices like smartphones, tablets, home gateways and connected cars. Rel-16 extended
the capabilities of MBMS to support dedicated broadcast networks for the transmission of linear
television and radio services. Among others, the standard supports the following key features:
- Support of Free-to-Air (FTA) services
- Broadcast-only service for UEs with no MNO broadcast subscription
- Decoupling of content, MBMS service and MBMS transport functions
- Exposure of eMBMS service and transport capabilities to third parties.
- Single Frequency Network (SFN) deployments with Inter-Site Distance (ISD) significantly larger
than a typical ISD associated with typical cellular deployments
- Support for Receive-Only Mode (ROM) services and devices
Rel-17 is currently addressing additional functionalities such as the support of UHF band frequencies
(with 6/7/8 MHz carrier bandwidths) or the connection of LTE-based 5G Broadcast to 5G Media
Streaming, so the latter serves as the entry point for service providers to the complete 5G media
distribution platform.
The 5G-MAG Reference Tools
The 5G-MAG Reference Tools project was started in late 2021. Since then, a steadily growing
developer community is committed to create common open-source reference tools to support
implementation and interoperability of 5G Media technologies.
The initial focus of the project was the development of Rel-16 5G Media Streaming and LTE-based 5G
Broadcast client components, server/headend and corresponding 5G unicast and broadcast radio
emulators. For that reason, multiple software components have been implemented and made publicly
available on Github
2
. The overall architecture of the 5G-MAG Reference Tools is depicted in Figure 1.
The main components of the 5G-MAG Reference Tools are the rt-mbms-modem (MBMS Modem), the
rt-mbms-mw (MBMS Middleware) and the rt-wui (Webinterface).
2
http s://g ithub.com/5G-MAG
“This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.”
Figure 1: The architecture of the 5G-MAG Reference Tools
MBMS Modem
The MBMS Modem builds the lower part of the 5G-MAG Reference Tools. Its main task is to convert a
5G broadcast input signal to Multicast IP packets on the output. The MBMS Modem is implemented as
a standalone C++ application which uses parts of the srsRAN
3
library.
The main components of the MBMS Modem are implemented as modules for a better structure and to
easier improve specific parts:
The Soapy Reader module processes the input signal that can either be received as I/Q raw data f rom
a Software Defined Radio (SDR) or as a prerecorded sample file . The usage of sample files provides a
convenient way to implement and test new features and to showcase specific functionality of the MBMS
Modem.
The Physical Layer module (PHY) is responsible for synchronization, OFDM demodulation, channel
estimation, decoding of the physical control and user data channels. The Medium Access Control
(MAC) module evaluates the Downlink Control Information (DCI) and the Control Format Indicator
(CFI), as well as the System Information Block (SIB) and the Master Information Block (MIB). Moreover,
a decoding of the Multicast Control Channel (MCCH) and Multicast Traffic Channel (MTCH) is
perf ormed. Additionally, the MBMS Modem uses the Radio Link Control (RLC) and Gateway (GW)
module to output MTCH data on a tun network interface. The output of the MBMS Modem is a UDP
multicast that can be further processed by the MBMS Middleware or directly be accessed by an
external application or media player.
The MBMS Modem can be configured via a configuration file and writes important status messages to a
log file. In addition, it exposes a RESTful API for dynamic configuration and querying status information.
MBMS Middleware
The MBMS Middleware presents the heart of the 5G-MAG Reference Tools. Its main task is to provide
the best available content to the (internal or external) application at any time. If available, it combines
content from (mobile) broadband, WiFi with the 5G BC content from the MBMS Modem using an
3
http s://g ithub.com/srsran/srsRAN
“This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.”
advanced decision logic. The content is presented to the applications in form of an intelligent edge
cache ready for pick up via http(s).
The MBMS Middleware uses the UDP multicast IP packets from the MBMS Modem. If the payload
contains FLUTE encoded content (files, i.e. Service Announcement, DASH, HLS) the MBMS
Middleware decodes the packets with its FLUTE/ALC decoder
4
into files. The MBMS
Middleware includes a web-cache server and each service is available like an CDN publishing point
including manifest and segment files.
Like the MBMS Modem, the MBMS Middleware can be configured via a configuration file and writes
important status messages to a log file. In addition, it exposes a RESTful API for dynamic configuration
and querying status information. The RESTful API is used by the Web-User Interface to query the
location of the FLUTE decoded manifest and segment files.
Webinterface
The Webinterface provides a graphical interf ace with a control display. Its main purpose is to collect
and display useful information from for the MBMS Modem and MBMS Middleware. For that reason, it
uses the RESTful APIs provided by both processes. It also enables use cases where the 5G-MAG
Reference Tools can be used for simple measurements (e.g., mobile measurements) or as a
standalone device (e.g., set-top box, mobile phone/tablet showcase). The web-user interface consists
of three tabs, one for each process. In addition, the Webinterface works as a media player using
dash.js
5
and hls.js
6
as external dependencies for the playback of the FLUTE decoded DASH and HLS
streams provided via the MBMS Middleware.
Use case 1: LTE-based 5G Broadcast
The first use case addressed by the 5G-MAG Reference tools focuses on the reception of an LTE-
based 5G Broadcast. LTE-based 5G Broadcast can be used to:
Distribute public and commercial linear TV and radio services, free-to-air or encrypted, to 3GPP-
compatible devices such as smartphones, smart TVs, or car infotainment systems;
Enable personalized media offers by delivering linear broadcast content alongside catch-up and
on-demand using the same family of standards;
Enable broadcast distribution of linear TV and radio services integrated into existing media
applications with 3GPP-def ined APIs.
A simplified illustration of the basic workflow for the processing of an LTE-based 5G broadcast in the
5G-MAG Reference Tools is depicted in Figure 2. The 5G broadcast or a sample file are processed by
the MBMS Modem resulting in a UDP multicast output. In case the 5G broadcast contains an RTP
stream the output of the MBMS modem can directly be played in a third-party media player such as
VLC or ff play. For FLUTE encoded DASH and HLS files the output of the MBMS Modem is further
processed in the MBMS Middleware. The MBMS Middleware uses the Service Announcement (SA
Parser) to set up a FLUTE decoder and saves the FLUTE decoded media files on a file server.
Moreover, the MBMS Middleware modifies specific timing values in the DASH and HLS manifests to
account for delays in the broadcast delivery. As a result, the client will not attempt to request files that
have not yet been received. Once the media files have been cached in the MBMS Middleware they can
be accessed by the Webinterface or any other DASH and HLS mediaplayer. The 5G-MAG Reference
Tools use a Reverse nginx Proxy to perform an internal mapping of specific ports and routes to the
4
http s://g ithub.com/5G-MAG/rt-libflute
5
http s://g ithub.com/Dash-Industry-Forum/dash.js
6
http s://g ithub.com/video-dev/hls.js/
“This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.”
standard ports used for http(80) and https (443). The Webinterface itself integrates dash.js and hls.js
for playback of the DASH and HLS streams directly in the browser.
Figure 2: The basic work flow of LTE-based 5G broadcasting in the 5G-MAG Reference Tools
Use case 2: Broadband-broadcast seamless switching
With seamless switching, universal service coverage can be provided by the complementarity of
different networks and delivery mechanisms. In cases in which certain users are out of 5G broadcast
coverage, the media playback is not disrupted, and the service continues to operate with unicast
fallback from the 5G broadband network. In this way, quality of service conditions can be maintained at
an exceptionally high level, and the user experience can be improved according to the needs of users
and/or operators.
Technically, these requirements present two main challenges: push vs. pull availability of the data, and
a time offset introduced by the added latency of 5G-Broadcast (5G-BC) incurred by the broadcast data
acquisition mechanisms of the BC Core components and the lower broadcast layers in the RAN.
Playlists, video, and audio segments are collected from the content provider origin by the BC Core, and
pushed through 5G-Broadcast to the clients, where they arrive with some delay. The clients can also
pull all these files from a CDN individually but will receive different content for the playlists/manifests, as
the delay means that the version received through 5G-BC will be older than the one loaded from the
CDN.
To enable seamless switching of the video playback, the middleware must ensure that every audio and
video segment has either been received through 5G-BC or can be fetched from the CDN in time for the
player's request of this segment. This effectively precludes using the manifests from CDN directly, as
the 5G-BC latency means they present segment availability too close to the live edge.
“This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.”
This becomes especially pertinent in cases where a client can receive a particular stream only from the
CDN, and then either enters an area where this stream can also be received through 5G-BC; or when
this stream becomes available through 5G-BC by scheduling or by a dynamic provisioning mechanism.
In the reference implementation of this use case, we demonstrate a simplified first approach for these
challenges constrained to HLS streaming. For that reason, the architectur e of the 5G-MAG Reference
Tools is extended by additional components as illustrated in Figure 3. The handling of audio/video
segments and playlists/manifests is split up into different components:
The Cache Management component handles the segment data, which is stored when received
through 5G-BC. A request from the player for a segment that has not yet been received triggers a
cache miss, causing this segment to be immediately fetched from the CDN. In the current
implementation, a 404 status is returned to the player's request, mimicking a request too close to the
live edge and causing the player to retry with progressive intervals.
The playlists/manifests are handled by Playlist Management, which creates them dynamically when
requested by the player. This component also receives playlists incoming on 5G-BC, and periodically
requests playlists from CDN. From these two sources, the content of the playlists that are created and
presented to the media player is determined: for 5G-BC playlists, it is assumed that the latest contained
file should be available on 5G-BC, and hence can be presented as such to the player; whereas for CDN
playlists, a configurable number of segments is stripped out of the playlist to offset the expected 5G-BC
delay. For the mediaplayer itself it is not visible whether the manifests and segments originated from
5G-BC or from a CDN.
Figure 3: Enhanced architecture of the 5G-MAG Reference Tools to support Broadband-broadcast seamless switching
Conclusion
The global introduction of 5G and the trend to consume high-quality videos over mobile networks lead
to a high demand for robust streaming service architectures on top of the complex 5G distribution
platform. The 5G-MAG Reference Tools project has been established to provide an open-source end-
to-end platform to support implementation and interoperability of 5G Media technologies.
“This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.”
In this paper we gave a detailed overview of the 5G-MAG Reference Tools focusing on two specific use
cases “LTE-based 5G Broadcast” and “broadband-broadcast seamless switching”. The implementation
of the 5G-MAG Reference Tools is based on the Rel-16 3GPP 5G specifications for 5G Media
Streaming and LTE-based 5G Broadcast. LTE-based 5G Broadcast can be used to distribute public
and commercial linear TV and radio services, free-to-air or encrypted, to 3GPP-compatible devices
such as smartphones, smart TVs, or car infotainment systems. With broadband-broadcast seamless
switching, universal service coverage can be provided by the complementarity of different networks and
delivery mechanisms. In cases in which certain users are out of 5G broadcast coverage, the media
playback is not disrupted, and the service continues to operate with unicast fallback from the 5G
broadband network.
The main components of the 5G-MAG Reference Tools are the rt-mbms-modem (MBMS Modem), the
rt-mbms-mw (MBMS Middleware) and the rt-wui (Webinterface). For both use cases, LTE-based 5G
Broadcast and “broadband-broadcast seamless switching” the broadcast signal is processed by the
MBMS Modem and exposed as a UDP multicast to the MBMS Middleware. The MBMS Middleware
decodes the FLUTE encoded DASH and HLS files and perf orms necessary manifest timing
manipulations. Via an internal web server and a reverse proxy, the manifest files and the media
segments are accessible by the Webinterf ace. The Webinterface uses open-source players such as
dash.js and hls.js for playback of the media streams directly in browser-based environments. For
“broadband-broadcast seamless switching” the 5G-MAG Reference Tools were extended by additional
components to enable intelligent caching of files coming either from the 5G broadcast or via unicast
directly from a CDN.
Future work will focus on further combining broadcast coverage and unicast connectivity. That way the
seamless-switching use-case can also be used for other scenarios, like regional and local content
insertions, content replacement, and on-demand or targeted advertising. While the developed tools
focus on 5G-based distribution, they also may serve as a reference or integration platform for traditional
broadcast networks and services. As an example, the integration of a DVB-I service layer is an ongoing
effort. In addition, the developed tools closely align with the service layer of ATSC3.0.
In further development steps, the addition of Rel-16 5G Media Streaming functionalities will enable
interaction between 5G broadcast and unicast together with overlaying services. As a result, the 5G -
MAG Reference Tools further enhance the 5G media ecosystem and serve as foundation for validation,
verification, demonstration, trials, and even commercial services. Moreover, the current Linux-based
implementation of the 5G-MAG Reference Tools will be extended to support a multitude of devices
such as smartphones, set-top boxes, car entertainment systems, wearables, and other Android -based
platforms
How to participate
The participation in the development of the 5G-MAG Reference Tools is open, i.e. not just limited to
5G-MAG members, quite the contrary we hope to attract researchers and independent developers into
the community. More information can be found on: https://www.5g-mag.com/reference-tools
References
[1] 99Content, “Generation Z Statistics“, https://99firms.com/blog/generation-z-statistics, Last accessed
on March 16th 2022
[2] Ericsson, “Ericsson Mobility Report”, November 2021,
https://www.ericsson.com/4ad7e9/assets/local/reports-papers/mobility-
“This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information
Technology Conference and is republished here by permission.”
report/documents/2021/ericsson-mobility-report-november-2021.pdf, Last accessed on March 16th
2022
[3] 3rd Generation Partnership Project, Technical Specification Group Services and System Aspects;
5G Media Streaming (5GMS); General description and architecture (Release 16) - TS 26.501, April
2021
ResearchGate has not been able to resolve any citations for this publication.
This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information Technology Conference and is republished here by permission
  • Ericsson
Ericsson, "Ericsson Mobility Report", November 2021, https://www.ericsson.com/4ad7e9/assets/local/reports-papers/mobility-"This paper first appeared in the Proceedings of the 2022 NAB Broadcast Engineering and Information Technology Conference and is republished here by permission." report/documents/2021/ericsson-mobility-report-november-2021.pdf, Last accessed on March 16 th 2022