hi-STAR objectives
On the basis of the recent market analysis, global total mobile data traffic reached around 33 EB per month by the end of 2019, and is projected to grow by a factor close to 5 to reach 164 EB per month in 2025. Populous markets that launch the fifth generation (5G) mobile network early are likely to lead traffic growth over the forecast period. By 2025, 45% of total mobile data traffic will be carried by 5G networks. Smartphones generate about 95 percent of the mobile data traffic. In Central and Eastern Europe, over the forecast period, the monthly traffic per smartphone is expected to increase from 5.8 GB to 24 GB per month. Although 5G is still expected to be the fastest-deployed mobile communication technology in history, short-term growth may be slowed in some countries due to delays caused by COVID-19.
A major technical challenge is designing future wireless communication networks that will support a range of applications and services. Contemporary wireless networks, such as 5G, beyond-5G (B5G) and the sixth generation (6G) mobile networks should enable high data rate demands, high reliability, strong security, low latency and energy consumption, as well as high density of user terminals. They should be able to offer emerging applications and services such as smart cities and smart farms, intelligent transportation systems, augmented reality, massive machine-to-machine (M2M) communications and Internet-of-Thing (IoT) applications. Given the large number of existing and emerging wireless technologies there are ongoing efforts in developing so-called heterogeneous networks (HetNet), that focus on combining the available multiple wireless technologies at the same location following always the best connected (ABC) principle.
Space technologies have become indispensable in the daily lives of European citizens. The value generated from the space related activities is estimated between EUR 46 to 54 billion representing a share of 21 % of the worldwide business. The capacity to use space is a strategic asset for Europe, which impacts many other sectors because it influences development of many early-stage and high-tech companies. On the basis of indicators of European Innovation Scoreboard 2020, Serbia is a moderate innovator having innovation index 67.4. Over time, performance has increased relative to that of the EU in 2012. „Innovators“ and „Innovation-friendly environment“ are the strongest innovation dimensions, while the „Attractive research systems“ represent one of the weakest innovation dimensions, which should be addressed in the forthcoming period. The realization of this Project will be the chance to improve this weakness and to push Serbia to a region of strong innovator group.
One of the open research and innovation challenges is the integration of non-terrestrial networks (satellites, unmanned aerial systems or high altitude platforms) with 5G terrestrial network. It would be useful for relevant stakeholders to valorize unique characteristics of non-terrestrial networks, such as wide coverage, multicast capabilities and complementariness with terrestrial network. Inclusion of satellites with terrestrial 5G is essential to offload the terrestrial network by broadcasting popular content to the edge of network or directly to users. Satellites can be extremely useful in enhancing mobile broadband (moving platforms such as aircrafts, vessels, and trains), and in supporting massive machine-type communications (offloading terrestrial IoT network through backhauling, or providing service continuity in cases where terrestrial network cannot reach). While major industry players (like OneWeb, Facebook or SpaceX) do a great deal to design physical layer of Low-Earth-Orbit (LEO) satellite networks and merge them with terrestrial networks, academia extensively searches for architectural design of such integrated networks that achieve efficient 5G data offloading by LEO-backhauled cells. We refer to the recent work by Di et al. and reference therein.
The hi-STAR project addresses one of the most critical challenges for the next generation wireless networks, which is integration of non-terrestrial networks with terrestrial 5G network. The general objective of the project is to develop flexible framework for integrated terrestrial 5G and Low-Earth-Orbit (LEO) satellite networks, where traffic management is performed with assistance of newly developed artificial intelligence methods
The underlying framework will support high user mobility, and will be modularly developed in order to support existing wireless technologies. The project results will enable us to offer a flexible solution to the wireless network operators. This solution will facilitate the introduction of new services to the users and also it will considerably improve the performance of the existing services. In addition, the operators will be able to offer proprietary solutions to specific user demands that are not covered by the mainstream standards and technologies. In this way, the network operators will gain flexible and cost-effective wireless communication infrastructure that is bound to help them achieve a stable and profitable business. The European and worldwide users will receive a wide spectrum of services that will make their business operations easier, increase their business success, and improve the overall quality of their everyday life. Basic ideas of this Project have been presented to the management and engineers of the incumbent telecom operator in Serbia - TELEKOM, and two perspective high-tech companies in the field of wireless communications and electronics. They gave us strong support to continue with realization of the ideas and they signed official Letter of support for hi-STAR Project.
Objective 1: To design and analyze innovative integrated satellite-terrestrial network
This objective will be achieved through cutting-edge research in the field of channel modeling, modulation techniques and coding theory. The first level of research will address defining of precise statistical channel models for satellite and terrestrial channels. Channel models, specified during work on this objective, will be implemented on Field-Programmable Gate Array (FPGA) in the scope of other objectives. These activities are intended to analyze communication networks with terminals connected via satellite and terrestrial links in terms of communication capacities, reliabilities of physical and data-link layer communications under more realistic propagation conditions then considered in the state-of-the-art literature. Theoretical results under this objective dictate a choice of modem and coder/decoder architecture that will be realized through further objectives. This objective will be closely connected with development of Hybrid User Terminal (HUT) and design of Intelligent Traffic Control Unit (ITCU). The HUT comprises ITCU and two modem units (satellite and 5G modems). The ITCU controls the upstream traffic forwarding via 5G and satellite radio access networks based on current radio link quality and/or on the policy rules received from the network side. We aim to propose end-to-end architecture of communication system with traffic control capabilities, i.e., switching, steering and splitting traffic between 5G and satellite networks.
Objective 2: To implement high-performance modems for satellite and terrestrial channels on advanced FPGA boards
Tool for achieving the objective is cutting edge RF System-on-a-Chip (RF-SoC) research platform, with powerful FPGA chip and ARM processor, which enables efficient software/hardware decompositions of modems functionalities. The DVB-S2X modem (for satellite channel) and 5G modem (for terrestrial channel) will be implemented with help of publically available all-software frameworks, like GNU radio and Open Air Interface. To provide high-throughput solutions, a portion of time critical modems functionalities will be accelerated by using FPGA chip. The objective will be accomplished by optimizing resources available on the RF-SoC platform, integrating IP core solutions and customly designed software/hardware blocks.
Objective 3: To develop novel Hybrid User Terminal (HUT)
In order to achieve this specific objective, the activities are aimed at progressing the project to a new stage, where theoretical results, previously achieved under Objective 1, are used to define attributes and design the ITCU module that represent a heart of traffic control unit at user side. The ITCU will track propagation changes and control traffic flow according to ABC paradigm. It will integrate artificial intelligence algorithms in order to learn the optimal traffic control under desired channel conditions, service class and communication protocols. The results under this objective will be used further in the process of integration of functional high-throughput modems (satellite and 5G) into RF-SoC platform, following the recommendations and definitions from the relevant standards.
Objective 4. To design intelligent network core traffic distribution controller
These activities are dedicated to provide sufficient set of network core functionalities for testing and verification of the HUT module and to investigate and develop HUT business models from the network operator point of view. The main goal is to develop basic set of network core functions and gateway unit that is necessary as the merging point for the upstream traffic from the HUT that can travel via satellite and terrestrial radio access networks. Also, the gateway unit and downstream networks core functions provide the possibility to send traffic in downstream direction towards HUT in order to test the receive part of the HUT. These set of functions, protocols and signalization will be developed jointly with team members working in realization of Objective 3 since the HUT and network side needs to be compliant with each other. Additional research is dedicated to network core edge controlled traffic distribution across 5G/SAT cells cluster in order to optimize the radio access network usage and Quality-of Service (QoS) for users.
Objective 5: To experimentally demonstrate the key concept and advanced techniques
We intend to integrate physical and potentially data link layers (DLL) of communication stacks for both 5G and satellite transmitter/receiver in RF-SoC research platform, as well as HUT functionalities. We aim to prove that RF-SoC platform can be used for high-throughput HUTs and that benefits of using HUT itself overcome the implementation costs. We will verify and validate not just HUT’s functionalities but also possibility to achieve integrated solution.