Multicast Broadcast Single Frequency Network Research Articles

Dynamic MBSFN Beam Area Formation in 6G Multibeam Non-Terrestrial Networks

Providing innovative services and ensuring ubiquitous, ultrahigh-density, extreme-data-rate, and very low latency communications are essential for future sixth-generation systems, where the importance of non-terrestrial networks (NTNs) will incredibly rise. However, the management of both the capacity and the radio spectrum remains one of the main challenges, when a huge number of devices require access to dissimilar broadcast services at the same time. To cope with these issues, traditional single-beam satellite systems can be replaced with very high throughput satellite, where multibeam transmissions increase the capacity and improve the spectrum utilization while limiting interbeam interference. In this article, we propose a dynamic multicast/broadcast single-frequency network (MBSFN) beam area formation (D-MBAF) algorithm that dynamically groups beams into dedicated MBSFN beam areas (MBAs) to increase the aggregate data rate (ADR) of the multibeam NTN system and deliver a given video content to all the interested NTN terminals. D-MBAF leverages multicast subgrouping by clustering the NTN terminals into different MBAs that are simultaneously served with different data rates. Furthermore, the D-MBAF algorithm delivers the video content in different flows: the base layer with lower resolution and a set of enhancement layers with higher resolutions. Radio resources are efficiently allocated to avoid interference among the beams belonging to different MBAs. A simulation campaign is carried out under different scenarios to assess the effectiveness of the proposed D-MBAF algorithm in terms of mean throughput, ADR, resource block utilization, and number of sent layers. Obtained results confirm that the D-MBAF algorithm outperforms the single-frequency multibeam transmission and the multilayer video delivery schemes used as benchmarks.

The MBSFN-based eMBMS using the method of Incremental Allocation of Radio Resource between Unicast and Multicast (IARR-UM)

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.

MBSFN or SC-PTM: How to Efficiently Multicast/Broadcast

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.

Mode Selection Algorithm for Multicast Service Delivery

The ever-growing demands for data-hungry services make the multicast play an increasingly important role in service delivery. 3GPP has enabled multicast for cellular network, including the adoption of two distinct multicast modes, Multicast/Broadcast Single Frequency Network (MBSFN) and Single Cell Point to Multipoint (SC-PTM). However, the lack of flexible selection between different multicast modes limits the transmission capacity. In order to further increase system throughput, this article focuses on exploiting the complementarity between MBSFN mode and SC-PTM mode, namely selecting the appropriate multicast mode for each cell in the network. This approach benefits from the trade-off between the utilization of user diversity via SC-PTM and the extra SFN gain from MBSFN, which increases the system throughput from a perspective of enhancing configuration flexibility. By constructing the analytical model of the network comprising cells with different multicast modes, we formulate a multicast mode selection problem aiming to maximize system throughput. Then, the formulated mixed-integer nonlinear programming problem is converted to a Difference of Convex (DC) programming, which is solved by the proposed algorithm based on the concave-convex procedure. Considering potential massive scale networks and high selection frequency, alternative mode selection algorithms with lower complexity are also designed.

UE-TV: User-Centric Energy-Efficient HDTV Broadcast over LTE and Wi-Fi

This paper presents an innovative multi-faceted architecture, called UE-TV, for user-centric, revenue aware, and energy-efficient TV broadcast. Scalable high-efficiency video coded high definition television (HDTV) content is broadcast over LTE multicast/broadcast single frequency network (MBSFN) along with the available Wi-Fi access points (APs). The proposed framework adaptively encodes the TV content and allocates radio resource based on current network. Stackelberg two-stage game theoretic approach discerns an optimal transmit power at the LTE base stations (eNodeBs) and the proportion of subscribers that are respectively served by eNodeBs and available Wi-Fi APs. Varied user equipment (UE) resolutions, users' energy/price sensitivities, and channel conditions govern the service options and user satisfaction. Our analysis and simulations show that, in comparison with the broadcast schemes over MBSFN without or with adaptive video coding, UE-TV framework significantly enhances the user satisfaction via optimized price/quality trade-off as well as energy saving at the eNodeBs and UEs.

Efficient 5G Small Cell Planning With eMBMS for Optimal Demand Response in Smart Grids

Smart Grids (SGs) are emerging cyber-physical systems, equipped with sophisticated communication and information technologies, for efficient and large-scale power supply and management. SGs demand advanced communication technologies between energy providers and consumers, for enabling a control-feedback loop, by using time-dependent pricing. In this paper, we propose an efficient planning of 5G small cells, with evolved multimedia broadcast and multicast communication, between aggregators (small cells) and SG consumers, for efficient demand-response (DR) programs. After pointing out that optimal multicast scheduling and radio resource management problem is NP-complete, we propose two different solutions, based on dynamic programming (DP) and greedy heuristics, for minimizing the energy cost for DR customers. We also analyze the performance of SG user capacity for 5G single cell multicast and multicast broadcast single frequency network. Extensive OPNET simulation results, over actual energy data and real wireless trace, demonstrate that our proposed 5G small cell planning and multicast solutions are capable of reducing energy production cost by $30\%$ , with up to $35\%$ shift in peak energy load, low latency and packet drop.

Joint Beamforming for Multicell Multigroup Multicast with Per-cell Power Constraints

This paper considers a joint beamforming design problem in the multicast broadcast single frequency network (MBSFN) scenario with multiple multicast groups that provide different multicast services. To solve the joint beamforming design among the cooperating base stations, which is also known as the joint processing scheme in the coordinated multipoint transmission (CoMP) defined in the long-term evolution-advanced (LTE-A) system, we devise different optimization techniques, such as semidefinite relaxation, fractional programming, and difference of convex (DC) programming. In this paper, per-cell power constraints are considered. In addition, we consider the design of higher rank transmission to increase the spectrum efficiency and the design of robust beamforming to alleviate performance degradation caused by imperfect channel state information. In the simulation results, we demonstrate the potential of the proposed algorithms in terms of the maximized minimum signal-to-interference plus noise ratio (SINR), and compare the proposed methods with the traditional MBSFN transmission scheme and the existing noncooperating multicast beamforming methods. The results show that the proposed methods, indeed, provide better performance. To complete the discussion, we also provide numerical results for the robust and nonrobust beamforming schemes in terms of the power consumption, feasibility ratio, and the histogram of the normalized SINR.

Adaptive handover scheme for evolved multimedia broadcast multicast services in long‐term evolution networks

The evolved multimedia broadcast multicast services (E-MBMS) can bring television (TV) services to a small mobile phone. The E-MBMS has been proposed in the third generation partnership project long-term evolution standardisation to support both normal mobile phone and mobile TV capabilities on a single device. As the E-MBMS delivers the same content simultaneously to multiple E-MBMS users sharing the same subframe in the multicast broadcast single frequency network (MBSFN) area and has the benefit of short handover latency when handover occurs within the MBSFN area; it is important to increase the number of E-MBMS users to be supported within the MBSFN area in order to achieve better performance in terms of spectral efficiency and handover latency. To obtain the advantages mentioned above, the proposed adaptive handover scheme increases the handover hysteresis margin (HM) when an E-MBMS user moves from the serving MBSFN area to the target non-MBSFN area and decreases the handover HM when an E-MBMS user travels from the serving non-MBSFN area to the target MBSFN area. Simulation results show that the spectral efficiency can be improved by increasing the number of E-MBMS users in the MBSFN area. Also, it is shown that the lower handover latency can be achieved by reducing the additional handover signalling message exchanges.

Resources Allocation Scheme Based on Mode Switch for Multicast Services in MBSFN

The multimedia broadcast and multicast services (MBMS) in 3GPP LTE is characterized by multicast broadcast single frequency network (MBSFN) operation. The multicast services are transmitted by single frequency network (SFN) mode, and the unicast services are delivered with point-to-point (PTP) mode. To avoid the network congestion of the multicast services in MBSFN, a novel resources allocation scheme (RAS) based on mode switch for the multicast services is proposed. The RAS takes advantages of the mode switch between SFN and PTP for the multicast services and minimizes the demanded radio resources of the maximum load cell. The simulation results show that the proposed RAS needs less demanded radio resources of the maximum load cell than SFN mode for all the multicast services.

Cross Layer Design for Efficient Video Streaming over LTE Using Scalable Video Coding

Third Generation Partnership Project (3GPP) Long Term Evolution (LTE) offers high data rate capabilities to mobile users, and network operators are trying to deliver a true mobile broadband experience over LTE networks. Mobile TV and Video on Demand (VoD) are expected to be the main revenue generators in the near future, and efficient video streaming over wireless is the key to achieve this goal. Video services use both unicast and multicast video transmission based on its applications. Enhanced Multimedia Broadcast/Multicast Service (EMBMS) is defined in 3GPP specification to support download delivery and streaming delivery to group users in LTE mobile networks. In 3GPP Release 8 specification, the EMBMS transmission is classified into single-cell transmission and MBSFN (Multicast Broadcast Single Frequency Network) transmission. In this paper, we propose a Scalable Video Coding (SVC) based video streaming scheme with dynamic adaptations and a scheduling scheme based on channel quality for unicast and multicast video transmissions. In our proposed unicast scheme, Channel Quality Indicator (CQI) feedbacks from User Equipment’s (UE) are used for dynamic adaptations and scheduling. Cross layer signaling between Medium Access Control (MAC) and Real Time Transport (RTP) protocols is used to achieve the channel dependent adaptation for unicast in video server. Simulation results for unicast indicate improved video quality for more number of users with reduced bit rate video traffic. Approximately 13% video quality gain is observed for users at the cell edge using this adaptation scheme. We have also proposed a scheduling scheme for multicast over MBSFN networks. This scheme optimizes the radio spectrum allocation by adaptive modulation and coding (AMC) and frequency scheduling based on distribution of users in different channel quality regions. Through simulations we demonstrate that spectrum savings in the order of 72 to 82% is achievable in different user distribution scenarios with our proposed scheme.