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Along with the commercialization of evolved multimedia broadcast multicast services (eMBMS), the number of mobile broadcasting users is growing notably. Previous works reveal that the accuracy of mobile channel estimation will significantly impact the quality of broadcasting services. Motivated by this fact, we apply machine learning (ML) to the fifth-generation Radio Access Network (5G RAN) slicing in this paper for the estimation and the prediction of the channel status in mobile scenarios. More specifically, a cascaded convolutional neural network (CNN)-long short term memory network (LSTM) architecture is developed to achieve channel estimation for mobile broadcasting users. The energy efficiency of the base station (BS) is modeled mathematically, and the sub-optimal solution is achieved by deep Q-Network (DQN) based on the available channel status. Finally, we present the simulation results to justify the performance of our proposed schemes.

Multimedia Broadcast Multicast Service (MBMS)-dedicated cell is a Long Term Evolution (LTE) based broadcast transmission mode with both high transmission efficiency and good compatibility with LTE unicast systems. However, since the physical design of Cell Acquisition Subframe (CAS), which is the control part of an MBMS-dedicated cell transmission period, does not take into account the long delay spread channels in Medium Tower Medium Power (MTMP) and High Tower High Power (HTHP) cells, receivers would probably suffer from multipath aliasing errors in practical transmission. This paper analyzes the impact of aliasing errors on channel estimation (CHE) accuracy and proposes an Aliasing-Elimination CHE algorithm for CAS reception. In the proposed algorithm, the pre-decoded Physical Broadcast Channel (PBCH) is reconstructed and utilized to generate a complete multipath distribution within the entire OFDM symbol length. By using this full-symbol length multipath distribution, the proposed algorithm eliminates aliasing errors effectively. Simulation results and complexity analysis show that the proposed CHE algorithm achieves a significant performance improvement compared to conventional CHE algorithms in long delay spread channels, with acceptable increment in complexity.

In Multimedia Broadcast/Multicast Service(MBMS), Multicast/Broadcast Single Frequency Network (MBSFN) and Single-cell Point-to-multipoint Network (SC-PTM) are two essential ways to organize networks to provide multicast services. MBSFN shows its unique advantage of enhancing signals at the boundary of two cells, however, highly requiring synchronization of symbols. SC-PTM shows the advantage of the flexibility on the network deployment. The comparison and complementarity of these two modes are explored. In this paper, we analyze the reception performance of MBSFN and SC-PTM from multiple perspectives. We first compare the successful transmission probability (STP) of MBSFN with that of SC-PTM. Then, we consider optimal power control problems in MBSFN and SC-PTM. The corresponding power control optimization problems are with fraction and max-min forms and solved by the Dinkelbach algorithm. Furthermore, we propose a joint mode-selection and power-control method in the hybrid mode of MBSFN and SC-PTM, where each cell could select the multicast mode from MBSFN and SC-PTM. This is a mixed-integer nonlinear programming (MINLP) problem and solved by the concave-convex procedure (CCCP) and the Dinkelbach algorithm. To further improve the throughput, the appropriate successful reception proportion is selected under the opportunistic multicast. Finally, the numerical simulations show the performance of our algorithms and compare the throughput of two modes, which verify our analysis.

The evolved Multimedia Broadcast Multicast Service (eMBMS) using the Multicast Broadcast Single Frequency Network (MBSFN) technique was designed for having multimedia streaming services using the multicast/broadcast way over the cellular network. Since (1) the unit of resource allocation in eMBMS-MBSFN is a subframe, (2) the code rate of an eMBMS-MBSFN session is based on the lowest Modulation and Coding Scheme (MCS) among involved User Equipments (UEs) of the eMBMS-MBSFN session and (3) the resource allocation for eMBMS-MBSFN cannot be so instantly and dynamically adjusted based on the status of involved UEs, triggering eMBMS-MBSFN in the inappropriate time and allocating inappropriate resource to eMBMS, for which a framework of how to set the configuration of the allocated resource for eMBMS-MBSFN has been defined in the standard, may cause (1) the radio resources to be wasted and (2) the low streaming quality and code rate. Based on the MBMS operation on Demand (MooD) concept, this work proposed the Incremental Allocation of Radio Resource between Unicast and Multicast (IARR-UM) method to dynamically allocate radio resources to eMBMS based on the current Radio Access Network’s (RAN’s) congestion situation such that some suitable multimedia streaming services are switched to eMBMS and others still use unicast communication. To effectively use eMBMS to mitigate RAN’s congestion, the proposed IARR-UM method (1) dynamically increases/decreases the amount of radio resources allocated to eMBMS, i.e., modifying the configuration of the allocated resource for eMBMS-MBSFN using the standard’s framework, based on the situation of RAN’s congestion, (2) uses the Knapsack algorithm to select a subset of suitable multimedia streaming services to be eMBMS sessions according to the given amount of radio resources allocated to eMBMS, and then (3) design a Common Subframe Allocation (CSA) pattern that can have the lower amount of redundant radio resources allocated to eMBMS. The results of the performance evaluation shown that the proposed method can (1) provide UEs with appropriate radio resources and (2), although the throughput may be reduced in some cases, effectively reduce (increase) the UEs’ invalid packet rates (data rates), especially in the higher density of UEs’ situation.

The 5G system can deliver simultaneouslyunicast services, multicast services and broadcast services using the conventional high-power high- tower (HPHT) infrastructure and with the same spectrum.The Third Generation Partnership Project (3GPP) LTEevolved -multimedia broadcast- multicast service (eMBMS) have new features designed for Terrestrial Broadcast services in Release 14. A broadcast service means only receive mode, only downlink no uplink or inserting a SIM card not needed. In free to air reception without a SIM card or without user device registration with the network the content can be received. This specification is standardized in release 15. In this study a two layer Layered-Division Multiplexing (LDM) is used in 5G new radio (NR).A significant performance could be analyzed in a 5G- NRMBMS by using two layer LDM system for delivering terrestrial broadcast services. The performance analysis demonstrated by computer simulations. Using two-layer LDM in 5G-NRMBMS system a high-qualityservice can be provided to both handheld and fixed devices

As a key infrastructure of Industry 4.0, Industrial Internet-of-Things (IIoT) promises the opportunity to build powerful industrial environments by leveraging the growing ubiquity of wired and wireless communication technologies. Designing a data delivery scheme in the future IIoT networks is undoubtedly a challenging task, as it should satisfy several conflicting requirements: massive-scale, data-intensive, and mission-critical, the requirements of which have motivated the desired need for feasible IIoT network architecture. In particular, the traffic characteristics of certain IIoT applications feature small-data patterns especially in typical automation control scenarios such as robot control on the downlink. In order to reduce the huge overhead associated with each individual unicast transmission of the small-data message, we propose a novel “multipoint-to-multipoint” and/or “point-to-multipoint with different contents” communication paradigm—Uni-Multi-Unicast (UMUcast), which is based-on traditional 4G technologies such as evolved Multimedia Broadcast Multicast Service (eMBMS) and Group Communication System Enablers (GCSE), and novel 5G technologies such as Multi-Access Edge Computing (MEC). For the downlink, the UMUcast transmitter can jointly encode multiple-sources’ small-data messages into a single chunk at MEC equipment in conjoint with a gNB, where chunk can be one-off transmission to multiple receivers simultaneously through an eMBMS frame, whereas the chunk is decoded into multiple small-data by each individual IIoT devices separately and respectively. The simulation results show that UMUcast has remarkable improvements over conventional point-to-point unicasting in handling multi-source, multi-destination, and massive small-data delivery with characteristics of low-overhead, high-throughput, and ultra-low-latency for future 5G-based IIoT networks.

The European Commission requires all European Union (EU) Member States to use telecommunications networks to alert the population of an ongoing crisis or an upcoming threat by June 2022. Public Warning System in Long Term Evolution (LTE) and 5G System currently supports a text-based warning using Cell Broadcast technology. Cell Broadcast does not support multimedia warning message delivery. This paper analyses requirements that need to be fulfilled to support multimedia warning message delivery in the 5G System and describes trials of a broadcast multimedia public warning alert system. The trials demonstrate delivery of multimedia public warning messages using Evolved Multimedia Broadcast Multicast Service (eMBMS), dynamic spectrum management and bonded connections. By using eMBMS the public warning messages can be sent with additional robustness and in multicast mode, resulting also in less congestion to the network as the messages do not need to be sent separately to each user. Dynamic spectrum management system allows to dynamically obtain spectrum resources for the public warning system messages and the bonded connections improves the throughput and reliability of the delivery by combining the capacity of several different networks.

The development of 5G system provides a unique opportunity to implement a unified wireless transmission platform that can simultaneous deliver unicast, multicast and broadcast services using the same spectrum and the same infrastructure. This can be achieved by developing a more capable point-to-multipoint transmission (PTM) system component, also called 5G Multimedia Broadcast Multicast Services (5G-MBMS). A properly designed 5G-MBMS could achieve the convergence of terrestrial mobile broadband and TV broadcasting systems.By inherently allowing dynamic spectrum allocation among different types of services, this converged system could offer significant higher spectrum utilization. In this paper, the power-based non-orthogonal multiplexing (P-NOM) technology is proposed in addition to the existing orthogonal time-division-multiplexing (TDM) scheme. Significant capacity gains could be achieved by using P-NOM in a 5G-MBMS system for delivering different types of broadcast services, and for delivering mixed unicast and broadcast services. The capacity benefits of a 5G-MBMS with P-NOM is demonstrated by both theoretical analysis and computer simulations. A key finding is that using a two-layer P-NOM can essentially deliver a broadcast service on top of a unicast network, each achieving nearly full capacity. Next, a complexity analysis will reveal that implementing P-NOM in a 5G-MBMS system does not require significant additional complexity at consumer devices. Finally, it will be shown that, different from the non-orthogonal-multiple-access (NOMA) technologies, using P-NOM in 5G-MBMS system requires little or no change to the existing radio resource allocation mechanisms in LTE and 5G, when one power layer is used for broadcast services delivery.

We present the latest developments in the physical layer evolution for the transmission of Multimedia Broadcast Multicast Service (MBMS) over fifth generation (5G) cellular networks. We first provide an overview of how the MBMS physical layer has evolved during the initial releases of the Third Generation Partnership Project (3GPP) specifications and provide motivations and insights for key developments that have helped mature MBMS into a competitive broadcasting solution. We provide an overview of dedicated MBMS carriers for Multimedia Broadcast multicast service Single Frequency Network (MBSFN) transmission as well as Orthogonal Frequency Division Multiplexing (OFDM) numerologies with longer cyclic prefixes to support MBSFN transmission over large geographical areas with large distances between cooperating cell sites. Next, we describe the most recent enhancements to the MBMS physical layer, addressing advanced use cases in the recently completed release of the 3GPP specifications (Release 16). First, we describe the physical layer design for enabling MBSFN-based MBMS services for rooftop receivers with inter-site distances between cooperating cell sites as large as 125 km. In this realm, we demonstrate the need for an OFDM numerology with a 300-microsecond cyclic prefix to communicate effectively over channels with very large delay spreads. Next, we explain how support for high mobility up to 250 kmph was added to the standards by using an OFDM numerology that gracefully trades off inter-symbol interference due to large delay spreads and inter-carrier interference due to large doppler spreads to achieve better performance than existing numerologies at high speeds. Finally, we describe the enhancements that were made to the Cell Acquisition Subframe (CAS)—specifically, the introduction of larger aggregation levels for the Physical Downlink Control Channel (PDCCH) and the support of Physical Broadcast Channel (PBCH) repetitions—that significantly increase the coverage for the control and system information associated with MBMS that are carried by these subframes.

As an emerging broadband service pattern in the 5G era, VR broadcasting needs a considerable amount of bandwidth and strict quality of service (QoS) control. The traditional eMBMS or enTV transmission mode in HetNets consisting of macro cells and small cells cannot bring about a good trade-off between broadband performance and resource utilization for VR broadcasting service. D2D multicasting applied to VR broadcasting can improve the performance of edge users and resource utilization. Motivated by the rapid development of AI techniques, this paper proposes a novel hybrid transmission mode selection based on online reinforcement learning to address this problem. Each VR broadband user can be associated by one of the three modes: macrocell broadcasting, mmWave small cell unicasting and D2D multicasting. This paper first models this intelligent mode decision process as a problem to pursue the optimal system throughput. Then, an online machine learning-based method is proposed to solve this problem, which consists of a fast D2D clustering module based on unsupervised learning and a smart mode selection module based on reinforcement learning. The simulation results verify that the WoLF-PHC and Nash Q-learning perform better than other algorithms in large-scale scenarios and small-scale scenarios, respectively. The proposed intelligent transmission mode selection can also achieve larger VR throughput than traditional broadcasting strategies with a good balance between broadband performance and resource utilization.

The demand for multimedia services is increasing at an astonishing speed. To deal with the overwhelming data traffic, approaches such as extending available bandwidth are proposed in wireless communication technology. Apart from the enlargement of bandwidth, the enhancement of the efficiency of resource usage is also grabbing the eye. 3GPP has introduced MBMS as a solution to improve the efficiency of resource usage since LTE release 8. Although going through many further enhancements in the recent releases, MBMS still needs modification to meet the requirements for applications in the future. Hence, for the emerging NR MBMS, more flexible network structure, deployment, and resource usage are the main topics for enhancements. In this paper, we identify that the system performance can be improved by adjusting the SFN area with the existence of inter-bearer interference. By allocating the same resources to different SFN areas, the system performance enhances in some cases. As such, we propose a graph-based solution called GGPA to address the problem of utility optimization. After an exclusion stage and a merging stage, GGPA outputs a result which partitions a given topology into multiple non-overlapping SFNs. The simulation results show that GGPA attains the sub-optimality in each identified scenario; in addition, it consumes less calculation time compared with exhaustive search. With the dynamic configuration of MBSFN areas resulting from GGPA, the NR MBMS could achieve better resource efficiency.

3GPP is now carrying forward the development of the point to multipoint transmission mode of 5G on the basis of the cellular infrastructure and standard. Since the dedicated proposal for multimedia broadcast multicast system (MBMS) was approved, the MBMS technologies are evolving with the update of the requirements from 3G to 5G. This paper reviews the latest progress during the evolved MBMS standardization, which focuses on the LTE-based 5G terrestrial broadcast mode. Some agreements in terms of two widely discussed topics during 3GPP meetings, cell acquisition subframe (CAS) enhancement and numerology refinement, are presented. The enhancement of CAS and the update of numerology aim to deal with the service outage issue in the case of covering large area and serving high-mobility users. To verify the improvement brought by the CAS enhancement and the new numerology, simulations from system level and link level are carried out by several organizations and the representative results are presented and analyzed in this paper.

In this letter, we propose an efficient encoding scheme for 3GPP Raptor codes. When encoding numerous information blocks with the same size, conventional encoder is similar to matrix multiplication in the first stage of the encoding. The main idea of the proposed method is to utilize the potential redundancy in the multiplication. A series of ordered operation instructions, stored in a variable called ${\it\text { Index}}$ , are established to achieve the goal. To construct ${\it\text { Index}}$ , two schemes are introduced in this letter. Analysis demonstrates that the proposed schemes have less complexity than the conventional one. Furthermore, the simulation results show that both of them take less than 1/3 the encoding time of the original method.

The LTE (Long-Term Evolution) eMBMS (evolved Multimedia Broadcast Multicast Service) technology employed in MBSFNs (Multicast Broadcast Single Frequency Networks) has been shown to be capable of considerably increasing the capacity of serving public safety users under group communication scenarios. However, due to its own limitations, a more fine-tuned scheduling approach is needed in order to fully utilize the strengths of eMBMS multicast. In this work, we first identify and analyze several overlooked challenges for scheduling multicast traffic in MBSFNs. Then we develop an effective and efficient dynamic scheduling algorithm for eMBMS multicast in time and frequency varying channel. The proposed algorithm leverages the advantages of both multicast and unicast schemes via user grouping; and through extensive simulations, is shown to be capable of significantly enhancing the mission critical performances under both best effort and guaranteed bit rate delivery models. We also show the resiliency of our proposed algorithm by applying it onto various network and user deployment scenarios. Our consistent results further prove that LTE eMBMS in MBSFN is a key solution in overcoming limitations in near future public safety networks.

Existing technologies in disaster and safety communication networks (DSCNs) face problems such as narrow bandwidth, low transmission rate, and difficulty in securing channels. Conversely, public safety long-term evolution (PS-LTE) technology provides high-speed, low-latency, quick-setup, and high-security data access for multimedia-based mission-critical services. To perform tests on each unit of core equipment with PS-LTE technology, a new call model such as push-to-talk, which is a service representing PS-LTE, is required. Moreover, objective and consistent metrics and methods are required for administering tests on the unique functions of DSCNs newly constructed with PS-LTE technology. This paper proposes a call model for the core facilities of DSCNs established in Korea, and it also suggests test and verification methods for all the areas of PS-LTE, including mission-critical push-to-talk, evolved multimedia broadcast and multicast service, and coverage and quality assessment for wireless services.

Ο ταχύτατα εξελισσόμενος τομέας των δικτύων κινητών επικοινωνιών έχει επιφέρει μία ιδιαίτερα αυξανόμενη απαίτηση για ασύρματη, πολυμεσική επικοινωνία. Στη ραγδαία εξέλιξη του τομέα αυτού συμβάλουν τα μέγιστα και οι απαιτήσεις της σύγχρονης αγοράς για ένα ενοποιημένο και λειτουργικό σύστημα κινητής τηλεφωνίας παρέχοντας παράλληλα πληθώρα ευρυζωνικών υπηρεσιών ψηφιακού περιεχομένου στους πελάτες - χρήστες του. Είναι γεγονός ότι τα τελευταία χρόνια τα δίκτυα επικοινωνιών τρίτης γενιάς (3G) - Universal Mobile Telecommunication System (UMTS) γνωρίζουν μεγάλη άνθηση και η χρήση τους έχει επεκταθεί στις περισσότερες ευρωπαϊκές χώρες, όπως και στην Ελλάδα. Τα νέα αυτά κινητά δίκτυα αντικαθιστούν τα υπάρχοντα κινητά δίκτυα δεύτερης γενιάς και επιπλέον προσφέρουν προηγμένες υπηρεσίες στους κινητούς χρήστες. Ωστόσο, η αδήριτη ανάγκη για μεγαλύτερες (ευρυζωνικές) ταχύτητες πρόσβασης οδήγησε στην περαιτέρω ανάπτυξη των 3G δικτύων και στην υιοθέτηση νέων τεχνολογιών, με κυριότερο εκπρόσωπο τους την τεχνολογία High Speed Packet Access (HSPA). Η τεχνολογία HSPA αποτελεί τη φυσιολογική μετεξέλιξη του UMTS, η οποία πολλές φορές συναντάται και ως 3.5G ή 3G+, προκειμένου να δηλώσει την αναβάθμιση του 3G (UMTS) προτύπου. Ωστόσο, παρά το γεγονός ότι η τεχνολογία HSPA αναμένεται να προσφέρει τη δυνατότητα παροχής πληθώρας ευρυζωνικών υπηρεσιών, το 3rd Generation Partnership Project (3GPP), που αποτελεί τον οργανισμό που προτυποποιεί τις νέες τεχνολογίες και ορίζει τις προδιαγραφές τους, ήδη μελετά και επεξεργάζεται νέες τεχνολογίες που θα επικρατήσουν την αμέσως επόμενη δεκαετία στην αγορά των κινητών επικοινωνιών. Το νέο αυτό project αποκαλείται Long Term Evolution (LTE) και στοχεύει στην επίτευξη ακόμη υψηλότερων ρυθμών μετάδοσης σε συνδυασμό με την αξιοποίηση μεγαλύτερου εύρος ζώνης. Κύρια προοπτική του LTE αποτελεί η διασφάλιση της ανταγωνιστικότητας και η επικράτηση του προτύπου στο χρονικό ορίζοντα της επόμενης δεκαετίας. Κατά συνέπεια, η αγορά κινητών επικοινωνιών σταδιακά μεταλλάσσεται προς τη δημιουργία δικτύων κινητών επικοινωνιών επόμενης γενιάς, με απώτερο σκοπό την επίτευξη της αποκαλούμενης "Κινητής Ευρυζωνικότητας" (Mobile Broadband). Ταυτόχρονα με την εκτεταμένη εξάπλωση των δικτύων κινητών επικοινωνιών επόμενης γενιάς καθώς και τις αυξημένες δυνατότητες των κινητών συσκευών, οι πάροχοι πολυμεσικού περιεχομένου και υπηρεσιών ενδιαφέρονται όλο και περισσότερο για την υποστήριξη της πολυεκπομπής (multicasting) δεδομένων στα δίκτυα αυτά με σκοπό την αποτελεσματική διαχείριση και επαναχρησιμοποίηση των διαθέσιμων πόρων του δικτύου. Επιπρόσθετα, οι χρήστες των κινητών δικτύων έχουν πλέον την απαίτηση να προσπελαύνουν εφαρμογές και υπηρεσίες οι οποίες μέχρι σήμερα μπορούσαν να διατεθούν αποκλειστικά από τα συμβατικά ενσύρματα δίκτυα. Έτσι λοιπόν στις μέρες μας γίνεται λόγος για υπηρεσίες πραγματικού χρόνου όπως mobile TV, mobile gaming, mobile streaming κ.α. Ένα από τα σημαντικότερα βήματα των δικτύων κινητών επικοινωνιών προς την κατεύθυνση της παροχής νέων, προηγμένων πολυμεσικών υπηρεσιών είναι η εισαγωγή της υπηρεσίας Multimedia Broadcast / Multicast Service (MBMS). Η υπηρεσία MBMS έχει σαν κύριο σκοπό την υποστήριξη IP εφαρμογών πανεκπομπής (broadcact) και πολυεκπομπής (multicast), επιτρέποντας με αυτό τον τρόπο την παροχή υπηρεσιών υψηλού ρυθμού μετάδοσης σε πολλαπλούς χρήστες με οικονομικό τρόπο. Η multicast μετάδοση δεδομένων σε κινητά δίκτυα επικοινωνιών είναι μια σχετικά νέα λειτουργικότητα η οποία βρίσκεται ακόμη στο στάδιο των δοκιμών και της προτυποποίησης της. Ένας multicast μηχανισμός μεταδίδει τα δεδομένα μόνο μία φορά πάνω από κάθε ασύρματο σύνδεσμο που αποτελεί τμήμα των μονοπατιών προς τους προορισμούς-κινητούς χρήστες. Το κρισιμότερο σημείο που εντοπίζεται κατά τη multicast μετάδοση δεδομένων στα κινητά δίκτυα επικοινωνιών είναι ο αποτελεσματικός έλεγχος ισχύος. Οι σταθμοί βάσης των κυψελωτών αυτών δικτύων διαθέτουν περιορισμένους πόρους ισχύος, γεγονός που περιορίζει τη χωρητικότητα της κυψέλης (cell) και επιβάλλει τη χρήση μίας βέλτιστης στρατηγικής για την όσο το δυνατόν καλύτερη αξιοποίηση των διαθέσιμων πόρων ισχύος. Ο έλεγχος ισχύος στοχεύει στη μείωση της εκπεμπόμενης ισχύος, στην ελαχιστοποίηση του θορύβου στο κυψελωτό δίκτυο και κατά συνέπεια στη διασφάλιση μεγαλύτερης χωρητικότητας επιπλέον χρηστών. Ένα από τα βασικότερα στοιχεία του ελέγχου ισχύος στα δίκτυα κινητών επικοινωνιών επόμενης γενιάς κατά τη multicast μετάδοση πολυμεσικών δεδομένων αποτελεί η επιλογή του κατάλληλου καναλιού μεταφοράς για τη μετάδοση των δεδομένων στον κινητό χρήστη. Συγκεκριμένα, πρόκειται για ένα κρίσιμο ζήτημα το οποίο είναι ακόμα υπό εξέταση στο 3GPP. Προς την κατεύθυνση αυτή, στο MBMS πρότυπο έχουν αναπτυχθεί διάφοροι μηχανισμοί, με χαρακτηριστικό τον MBMS Counting Mechanism. Στόχος του μηχανισμού αυτού είναι η βελτιστοποίηση της ροής δεδομένων για την υπηρεσία MBMS, όταν αυτά διέρχονται από τις διεπαφές του UMTS/HSPA δικτύου. Ωστόσο, η υπάρχουσα μορφή του μηχανισμού αυτού, καθώς και των αρκετών άλλων μηχανισμών που έχουν προταθεί από το 3GPP, διακρίνεται από πολλές αδυναμίες που δεν επιτρέπουν την αποτελεσματική και μαζική μετάδοση πολυμεσικών δεδομένων. Τα σημαντικότερα προβλήματα των μηχανισμών αυτών είναι η απουσία ευρυζωνικών χαρακτηριστικών καθώς και η σπατάλη σημαντικού τμήματος των ούτως ή άλλως περιορισμένων πόρων ισχύος. Εν γένει, η επιλογή του κατάλληλου καναλιού μεταφοράς των πολυμεσικών δεδομένων στο ασύρματο μέσο είναι μια δύσκολη διαδικασία καθώς μια λανθασμένη επιλογή καναλιού μπορεί να οδηγήσει στην αστοχία μίας ολόκληρης κυψέλης. Γίνεται σαφές λοιπόν, ότι απαιτείται μία βελτιωμένη έκδοση των υπαρχόντων μηχανισμών για την αποτελεσματικότερη και οικονομικότερη μετάδοση πολυμεσικού περιεχομένου σε μεγάλο πλήθος χρηστών. Λαμβάνοντας υπόψη τα παραπάνω, στόχος της παρούσας διδακτορικής διατριβής είναι η μελέτη του ελέγχου ισχύος στα δίκτυα κινητών επικοινωνιών επόμενης γενιάς καθώς και η ανάπτυξη νέων μεθόδων/μηχανισμών για τη βελτιστοποίηση του. Ιδιαίτερο χαρακτηριστικό της διατριβής αυτής είναι η ενσωμάτωση και η "εκμετάλλευση" όλων των ιδιαίτερων χαρακτηριστικών της HSPA τεχνολογίας στην MBMS υπηρεσία. Προς αυτή την κατεύθυνση, στην παρούσα διδακτορική διατριβή αναλύονται και αξιολογούνται όλα τα υπάρχοντα κανάλια μεταφοράς του UMTS και της τεχνολογίας HSPA τα οποία μπορούν να χρησιμοποιηθούν για τη multicast μετάδοση MBMS υπηρεσιών. Η αξιολόγηση γίνεται με βάση την απαιτούμενη ισχύ που πρέπει να ανατεθεί από το σταθμό βάσης για καθένα από αυτά, και κατά συνέπεια με βάση το ρυθμό μετάδοσης τους, τον αριθμό των χρηστών που μπορούν να εξυπηρετήσουν, την ποιότητα υπηρεσιών για κάθε χρήστη, τη μέγιστη δυνατή κάλυψη της κυψέλης κ.α. Οι ιδιαίτερα αυξημένες απαιτήσεις των MBMS υπηρεσιών μας οδήγησαν στη συνέχεια στη διερεύνηση και αξιολόγηση ορισμένων τεχνικών μείωσης της εκπεμπόμενης ισχύος, με απώτερο σκοπό την αποδοτικότερη χρήση των πόρων του συστήματος κατά τη μετάδοση MBMS υπηρεσιών. Ενδεικτικά αναφέρουμε πως μία MBMS υπηρεσία με ρυθμό μετάδοσης 128 Kbps μπορεί να καταναλώσει έως και το 80% των πόρων ισχύος ενός σταθμού βάσης. Επομένως, γίνεται κατανοητό ότι η μετάδοση MBMS υπηρεσιών με τόσο υψηλούς ρυθμούς μετάδοσης καθίσταται δύσκολη έως και αδύνατη. Για την αντιμετώπιση αυτού του προβλήματος έχουν αναπτυχθεί τεχνικές, όπως η FACH Dynamic Power Setting, η Macro Diversity Combining και το Rate Splitting, ικανές να μειώσουν τα επίπεδα ισχύος κατά τη μετάδοση multicast δεδομένων στους MBMS χρήστες. Η διδακτορική αυτή διατριβή εξετάζει την αποδοτικότητα της χρήσης αυτών των τεχνικών εξοικονόμησης ισχύος και παρουσιάζει πειραματικά αποτελέσματα που αποκαλύπτουν το ποσό ισχύος που εξοικονομείται από κάθε μία τεχνική. Η αξιολόγηση τόσο των καναλιών μεταφοράς όσο και των τεχνικών μείωσης ισχύος θα οδηγήσει στην εύρεση ενός κατάλληλου σχήματος/μηχανισμού, ο οποίος θα εξασφαλίζει την αποδοτική εναλλαγή μεταξύ των διάφορων τύπων καναλιών κατά τη μετάδοση MBMS υπηρεσιών. Ο μηχανισμός αυτός, τον οποίο καλούμε MBMS Channel Assignment Mechanism (ή χάριν συντομίας "MCAM"), αναμένεται να εξασφαλίσει βελτιωμένη απόδοση σε σχέση με τους αντίστοιχους μηχανισμούς που έχουν προταθεί από το 3GPP, μείωση της καταναλισκόμενης ισχύος και κατά συνέπεια αύξηση της χωρητικότητας των κινητών δικτύων επόμενης γενιάς. Ωστόσο, το πιο αξιοπρόσεκτο πλεονέκτημα του προτεινόμενου μηχανισμού, που ουσιαστικά τον διαφοροποιεί από τις άλλες προσεγγίσεις, είναι ότι προσαρμόζεται στις αυξημένες απαιτήσεις των κινητών δικτύων επόμενης γενιάς για ταυτόχρονη παροχή πολλαπλών πολυμεσικών συνόδων. Το γεγονός αυτό μπορεί να επιτρέψει τη μαζική μετάδοση πολυμεσικών δεδομένων σε πληθώρα κινητών χρηστών, θέτοντας κατά τον τρόπο αυτό τον MCAM σαν έναν ισχυρό υποψήφιο για τα δίκτυα επόμενης γενιάς.

This paper introduces the performance evaluation results of 5G multimedia broadcast multicast services (5G-MBMS), which can support terrestrial broadcasting based on a 3GPP network. To meet 5G broadcasting requirements from terrestrial broadcasters, 3GPP improved the capability of release (Rel-) 14 LTE-based further evolved MBMS (FeMBMS) so that it standardized 5G-MBMS in Rel-16. We compare the differences between FeMBMS and 5G-MBMS in terms of numerology and performance of physical channels based on computer simulations. The properties and decoding performance of the physical-layer of the 5G- MBMS show that it can guarantee terrestrial broadcasting reliability in various environments. Our laboratory test shows the delivery of media contents through an FPGA-based 5G-MBMS transceiver.

Broadcast/multicast technologies are a key enabler for multiple applications and services in the future 5G New Radio (NR). The 3rd Generation Partnership Project (3GPP) works for the new phases of the 5G standard in a novel multimedia broadcast multicast service (5G-MBMS). It will take advantage of the previous multicast approaches and emerging techniques like non-orthogonal multiple access (NOMA), helping to reach the goals of 5G cellular systems and beyond. This paper aims to define outperformance thresholds among broadcast/multicast access techniques for multimedia services in 5G networks. We define such thresholds among three multicast techniques: conventional multicast scheme (CMS), subgrouping based on orthogonal multiple access (OMA), and subgrouping based on power domain non-orthogonal multiple access (P-NOMA). We compare the multicast techniques' performance under a wide range of users' distributions, reception conditions, and specific throughput requirements of the broadcast/multicast multimedia service. We take advantage of the particle swarm optimization (PSO) algorithm to identify the multicast techniques' outperformance thresholds. The proposal and the complete analysis are based on evaluating the aggregated data rate (ADR) and a proposed group-oriented metric. The validation and results analysis shows the boundary conditions of performance among the considered multicast techniques and possible use cases.

In Multimedia Broadcast Multicast Service (MBMS)-dedicated cell, multipath aliasing is an inevitable challenge for CAS reception in long delay spread channels. Meanwhile, traditional Channel Estimation (CHE) algorithms may not work well in such scenarios. For overcoming this problem, an Aliasing-Elimination CHE (AE-CHE) algorithm was proposed. This novel algorithm utilizes the pre-decoded Physical Broadcast Channel (PBCH) to generate a full-symbol length multipath distribution. By using the multipath distribution, aliasing errors could be eliminated effectively. However, previous researches are mainly based on ideal factors such as perfect PBCH decoding, static channel without Doppler spread, which does not match the actual situation in practical receivers. This paper studies the effects of actual PBCH decoding ability and Doppler spread of time-variant channels on the performance of the AE-CHE algorithm. Analysis and simulation results show that the AE-CHE algorithm could also outperform the traditional algorithms even in the presence of non-ideal factors.

The evolved Multimedia Broadcast Multicast Services, eMBMS (evolved Multimedia Broadcast Multicast Service), promises to be a powerful method for distributing common multimedia content. However, rapid deployment of 5G broadcating services in China cannot be supported by eMBMS due to the obstacles of regional simple deployment and one-way interface between core network and RAN (Radio Access Network) side. This article fills the gap by describing solutions for new core network architecture. Two innovative solutions realize the control plane function. The proposed architecture alternative satisfies the objective needs of radio and television service deployment in China and reduces the complexity of signaling processing, which is favorable for collaborative coverage of broadcast and unicast.

The dramatic increase in data traffic poses a great challenge to the cellular network. To alleviate the pressure of the network and improve the spectrum efficiency, Multimedia Broadcast and Multicast Service (MBMS) is introduced to enable the point-to-multipoint transmission in the cellular network. To enhance the received signal strength (RSS) of cell edge users, the Multicast/Broadcast Single Frequency Network (MBSFN), which allows combining signals from different cells, is adopted. However, neighbor cells may incur the interference and include more users in bad conditions, which leads to lower transmission efficiency. As a result, an appropriate selection of the multicast mode for each cell is needed. In this paper, a deep reinforcement network (DRN) was proposed to obtain near-optimum solutions for the SFN area formation. We first design the input of the neural network to characterize the geographic locations of users. The output of the neural net is set to be a probability matrix, which parametrizes the mode selection status. A reinforcement learning framework based on the policy gradient scheme was adopted to bypass the acquisition of optimal labels. By training with different network layouts, DRN can produce near-optimum solutions for throughput maximization. The average increase of DRN above the traditional approach is also revealed by numerical simulation.

Further evolved Multimedia Broadcast Multicast Service (FeMBMS) was introduced in 3GPP Release 14 to provide standalone ultra-high-definition multicast/broadcast services over larger distances. Release 16 made significant improvements to FeMBMS with support for large inter site distance up to 125 km, support for high mobility up to 250 km/h, and enhancements to the cell acquisition subframe. However, the capabilities, efficiency, and service delivery flexibility of this system still lags behind dedicated broadcasting systems such as ATSC 3.0. Our previous works had shown that in an LTE infrastructure, incorporating layered division multiplexing (LDM) can deliver broadcast and broadband services in one RF channel to achieve higher spectral efficiency. The newest 5G standards bring many changes to the 3GPP specifications. Therefore, this study investigates the performance and capabilities of LDM for delivering mixed broadcast and broadband services for 5G and beyond. Simulations show that in an LDM enabled 5G broadcast priority network, a broadcast service and a near full capacity broadband service can be delivered using the same time frequency resource.

The scenario that quantities of users subscribing to a same live video content cluster together in a spatially local area poses challenges to cellular operators even in 5G unicast networks. In this regard, we propose a network paradigm exploiting eMBMS and edge computing, which relieves resource starvation in both backbone and wired access networks by grouping users and distributing the desired content to each multicast group only once. However, problems are raised by operators to perform an optimal server-side decision: how to partition users with the heterogeneity and dynamic of channel conditions, how to fairly and optimally allot resources considering both unicast and multicast users, and how to maximize the overall QoE of this live video service. To cope with these coupled problems, we formulate an optimization model based on coalition game with QoE assured, which defines a fair allocation strategy according to respective contributions and a dynamic grouping method. Subsequently, we propose a heuristic algorithm with a low-time complexity that guarantees QoE for most users and shows conspicuous reduction of annoying stalling events. Noticeably, numerical simulations reveal the fairness and near-optimality of our algorithm compared with state-of-the-art approaches in multiple scenarios.

Consumer demand for high definition video is growing, but current Long Term Evolution (LTE) networks lack sufficient capacity to broadcast the typical 10 to 20 TV channels concurrently broadcast in a geographic region. In response to growing demand, the Third Generation Partnership Program initiated a study into TV enhancements for multimedia broadcast/multicast service (MBMS) for LTE. 3GPP's further enhanced MBMS (FeMBMS) enables higher per cell bandwidth for MBMS services, simultaneous reception of both unicast and multicast services from different mobile network operators (MNOs), MBMS-dedicated cells, standalone MBMS, non-subscriber reception of TV services, and larger cell sizes. In addition, shared enhanced MBMS (eMBMS) networks and MBMS transport services enable MNOs to minimize costs from the content providers, while at the same time incentivizing the content providers to exploit LTE for linear TV services. Finally, by utilizing MBMS on demand (MooD) and dynamic MBMS, the resource allocations to the MBMS flows can be dynamically adapted; for example, the users' quality of experience can be further improved beyond that of legacy static MBMS resource allocation. This article describes the enhancements made to LTE eMBMS related to TV services, MooD, and use cases for each of the enhancements. Additionally, MBMS in 5G next-generation radio is also discussed. The scope of this article comprises the terminal, radio access, core architecture, and related services.

[EN] This paper provides a detailed performance analysis of the physical layer of two state-of-the-art point-to-multipoint (PTM) technologies: evolved Multimedia Broadcast Multicast Service (eMBMS) and Advanced Television Systems Committee - Third Generation (ATSC 3.0). The performance of these technologies is evaluated and compared using link-level simulations, considering relevant identified scenarios. A selection of Key Performance Indicators for the International Mobile Telecommunications 2020 (IMT-2020) evaluation process has been considered. Representative use cases are also aligned to the test environments as defined in the IMT-2020 evaluation guidelines. It is observed that ATSC 3.0 outperforms both eMBMS solutions, i.e., MBMS over Single Frequency Networks (MBSFN) and Single-Cell PTM (SC-PTM) in terms of spectral efficiency, peak data rate and mobility, among others. This performance evaluation serves as a benchmark for comparison with a potential 5G PTM solution., This work was supported in part by the European Commission through the 5GPPP project 5G-Xcast (H2020-ICT-2016-2) under Grant 761498. The views expressed in this contribution are those of the authors and do not necessarily represent the project.

The long-term evolution multimedia broadcast multicast service (MBMS) infrastructure has been shown to efficiently fulfill the requirements of classical vehicle-to-vehicle services, such as cooperative awareness message and decentralized environmental notification message delivery, which involve the transmission of the same message to a set of destination receivers in close proximity. When targeting autonomous driving applications, related 5G V2X services, such as cooperative collision avoidance (CCA), impose challenging latency and reliability requirements that cannot be generally guaranteed using the current MBMS architecture. In this paper, we propose a low-latency multicast scheme aimed at decreasing the end-to-end (E2E) communication latency. The proposed approach concentrates the multicast network functionalities into the layer-2 of the base stations (BSs) protocol stack, including a message passing between neighboring BSs, to achieve a fast management of multicast groups and a reduction of the communication path through the network infrastructure. The results show that the proposed technique can substantially decrease the E2E latency of conventional MBMS and ensure the correct operation of demanding services, such as CCA moving toward 5G communication systems.

The 3GPP Release-14 specification has enhanced long-term evolution (LTE) enhanced Multimedia Broadcast Multicast Service (eMBMS) to enable the provision of television services according to some of the requirements of the broadcasting industry. These improvements include radio interface enhancements, such as support for larger intersite distances in single-frequency network deployments and the introduction of more flexibility including a dedicated eMBMS carrier with 100% broadcast resource allocation. Although the performance of LTE eMBMS has been extensively evaluated by numerical computations, it is crucial to perform laboratory measurements that provide insights into the operation of the system in a practical setup. This paper describes the construction of eMBMS chains within the laboratory to carry out physical-layer measurements within a controlled environment and presents a methodology to measure the signal-to-noise ratio (SNR) of eMBMS signals (that can time multiplex both unicast and broadcast parts). The SNR thresholds at different modulation and coding schemes are measured independently in the laboratories of the British Broadcasting Corporation Research and Development and Institut fur Rundfunktechnik, and the results are compared with the results obtained with numerical evaluations.

LTE evolved Multimedia Broadcast/Multicast Service (eMBMS) is an attractive solution for video delivery to very large groups in crowded venues. However, the deployment and management of eMBMS systems are challenging, due to the lack of real-time feedback from the user equipments (UEs). Therefore, we present the Dynamic Monitoring ( DyMo ) system for low-overhead feedback collection. DyMo leverages eMBMS for broadcasting stochastic group instructions to all UEs . These instructions indicate the reporting rates as a function of the observed quality of service (QoS). This simple feedback mechanism collects very limited QoS reports from the UEs. The reports are used for network optimization, thereby ensuring high QoS to the UEs. We present the design aspects of DyMo and evaluate its performance analytically and via extensive simulations. Specifically, we show that DyMo infers the optimal eMBMS settings with extremely low overhead while meeting strict QoS requirements under different UE mobility patterns and presence of network component failures. For instance, DyMo can detect the eMBMS signal-to-noise ratio experienced by the $0.1th$ percentile of the UEs with a root mean square error of 0.05% with only 5 to 10 reports per second regardless of the number of UEs.

Mobile multimedia services have been increasingly popular. However, radio resources are limited. The quality of experience of all users in wireless networks can be enriched by resource allocation, which is affected by many factors in current wireless networks. In this paper, we focus on a hybrid unicast-multicast (HUM) video streaming scheme, and develop an adaptive resource allocation framework for HUM by combining adaptive cooperative transmission and base station handoff. The optimization problem is formulated as a multi-dimensional, complexity-constrained nonlinear NP-hard problem. To solve the problem, a greedy algorithm and a genetic algorithm are proposed. Simulation results demonstrate that our scheme has superior performance than other transmission methods in the literature. The genetic algorithm has better performance, but the greedy algorithm can maintain better balance between performance and resource consumption.

360-degree video content provides a rich and immersive multimedia experience to viewers by allowing viewers to the video from any angle. However, 360-degree videos require much higher bandwidth to be delivered over mobile networks compared to conventional videos. Multicasting of the videos is one of the solutions to efficiently utilize the limited bandwidth since many viewers share the wireless spectrum resource for popular videos, such as sports events or musical concerts. LTE eMBMS assigns the videos to the video sessions, and multiple viewers can subscribe to the same video allocated to the video sessions. Moreover, the tiling of the 360-degree video makes it possible to control the regional quality of the video. The tiles that are likely to be seen by many viewers should have higher quality than other tiles to satisfy more viewers. In this paper, we proposed the Multi-Session Multicast (MSM) system to optimally allocate the wireless resources to tiles with different qualities to maximize the expected user experience. The experimental results show that the proposed MSM system provides higher quality videos to viewers using limited wireless resources.

To improve signal quality of wireless enhanced Multimedia Broadcast and Multicast Services (eMBMS), a subspace signal enhancement scheme is proposed in this paper, where MBMS signal is enhanced by subspace filtering at the receiver. On this basis, a signal-to-interference-to-noise ratio (SINR) estimation method is considered to determine sustainable service level of MBMS users. Simulation experiments validate the effectiveness of the proposed schemes.

Multicast was introduced in Long-Term Evolution (LTE) in release 8 as the technology for the Evolved Multimedia Broadcast Multicast Services (eMBMS) and has been steadily updated in the later releases. Unlike unicast where available resources are split amongst each User Equipment (UE), in Multicast Broadcast Single Frequency Network (MBSFN), all the resources can be allocated to reach all UEs. This prominent advantage together with the prevalent signal improvement make MBSFN a popular LTE and 5G evolution technique. In this paper, we focus on the LTE Multicast Broadcast Single Frequency Network (MB-SFN) technology from the perspective of the MBSFN area and its application in public safety networks (PSNs). Since the MBSFN area plays a pivotal role in performance improvement and public safety incidents differ in their scales, using our state-of-the-art system-level simulations, we explore performance distributions within MBSFN areas of different shapes and sizes, as well as the impacts of MBSFN area locations relative to the network. We show that the results can give an informative insight into the MBSFN area for in-coverage performance prediction/evaluation or out-of-coverage mobile base station deployments.

In a traditional vehicle to anything (V2X) use case, we already have a sophisticated service provisioning infrastructure based on the Long-term evolution design for addressing a group of same content receiving entities through the evolved multimedia broadcast multicast services employment proven to be practically realizable apt architecture, more specifically viable for the connected autonomous vehicles (CAVs). With resource exploitation advantage in connected cars making up an Intelligent Transport System (ITS) comes the performance stringent challenges for the existing 5G eMBMS based V2X. This paper offers optimal performance requirements of ultra-reliable low latency communication (URLLC) through an extension of the obtainable local eMBMS based V2X and containerized user equipment (UE) model. Novel approach for maximized throughput due to locally containerized UEs is proposed and proved. Also high reliability is guaranteed via path diverse network with repeated microservice deployment over multiple CAVs involved in a certain process exhibiting redundant resource availability and their efficient exploitation. Solution constitutes a hybrid architecture of containerized services with reactive between and orchestrated within depiction.

5G-New Radio (5G-NR) technology is considered for a new mobile communication system. One of the most important services that provide an extra-advantage is terrestrial broadcasting for mobile systems. Previously, this service was handled by further evolved multimedia broadcast multicast service (FeMBMS) on the basic guidline of the Long Term Evaluation (LTE). Digital terrestrial television systems (DVB-T2) via single frequency networks (SFN) signals with orthogonal division multiplexing (OFDM) modulation are used to provide unicast/multicast/broadcast services for mobile systems. Terrestrial High Power High Tower (HPHT) broadcast transmitters and 5G mobile low power and low tower (LPLT) stations in mobile-cells can be rescheduled to reduce power consumption. The 5G-NR pre-license frequency band (in the UHF band) can be reused to broadcast data with TDM with the existing procedures like synchronization and standards for mobile communication technologies. In this article, a novel method is suggested to improve performance of the spectral efficiency (SE) and energy efficiency (EE) based on the optimization of the signal cyclic prefix (CP), symbol duration, and antenna gains for any SFN transmitters. All system parameters are chosen based on the real system and propagation standard ITU-R P.1546-5 at different with high-speed users. The simulation results demonstrate the proposed method for 5G-NR broadcasting achieves higher SE and EE around 12.5% and 40%, respectively. It means the proposed technique can maximize SE and EE by a sufficient CP, antenna gain and appropriate symbol duration.

Third Generation Partnership Project (3GPP) is now carrying forward the development of LTE-based 5G terrestrial broadcasting technology. Applying interleaving technology to LTE-based 5G terrestrial broadcasting was brought up in the discussion of Release 16, but consensus among researchers was not reached because of the inadequate consideration and verification. This paper first briefly introduces the main innovations in Release 16 and then focuses on the design of interleaver to meet the new requirements in LTE-based 5G terrestrial broadcasting. In specific, a novel transposed splitted block interleaver is proposed to increase the diversity gain in both time and frequency domain. Extensive analysis and simulation have demonstrated that the proposed interleaver can improve the mobile reception of LTEbased 5G terrestrial broadcast services up to 3. 59dB at the user speed of 250km/h. Therefore, the design of time and frequency interleaver can provide a feasible solution for the continuous burst errors in current system and propose potential alternatives for the enhanced future broadcast in 3GPP standard.

The 3rd Generation Partnership Project (3GPP) introduced the Further evolved Multimedia Broadcast Multicast Service (FeMBMS) transmission mode as an extension of the Long-Term Evolution (LTE) standard in 3GPP Release 14. FeMBMS enables the broadcast of services on a dedicated carrier and is currently being tested in numerous field trials worldwide. The New Radio (NR) air interface, standardized in 3GPP Release 15, introduced Low-Density Parity Check (LDPC) codes as a new forward error correction scheme, but does not yet support broadcast transmissions. The 5G NR standard is designed for unicast transmissions and only supports short codeword lengths.In contrast, the digital terrestrial television broadcast standards DVB-T2 and ATSC 3.0 both utilize LDPC codes with long codeword lengths as these have proven to increase the error correction performance of transmission systems.Similarly to FeMBMS, broadcast services based on 5G NR may be introduced in a future 3GPP release and would benefit from longer LDPC codeword lengths.The introduction of new codeword lengths into the 5G NR standard requires careful consideration of the existing coding procedures. After detailing the 5G NR LDPC coding chain, this paper presents a set of minimal extensions to the 5G NR standard required in order to realize longer LDPC codes. These extensions are evaluated and the achievable performance is compared to that of the LDPC codes standardized in the ATSC 3.0 specification.