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In this paper, we propose modulation and coding scheme level drop scheme for LTE evolved multimedia broadcast/multicast service (eMBMS) by transmitting additional parity information opportunistically with limited feedback overhead to improve the performance of the eMBMS. Our proposed scheme overcomes the limited performance of the conventional eMBMS due to the lack of dynamic link adaptation capability. We prove that the transmission performance of eMBMS can be improved significantly with the proposed scheme, which is verified with intensive system-level simulations.

In this paper we introduced interference cancellation (IC) in the cell search and the detection of physical downlink shared channel (PDSCH) in long term evolution (LTE) of 3rd generation partnership project (3GPP). After user equipment (UE) is turned on, it has to first search the target cell using synchronization channel (SCH). After UE gets timing and cell identification (Cell ID) by cell search process, it can start to transmit and receive data through the traffic channel. In most cases, UE experiences the interference from surrounding neighbor cells, which may result in the degradation of the receiver performance. Not only in time division duplex (TDD) but also frequency division duplex network (FDD), the cells must be deployed with the time aligned to support better successful handover and also provide multemedia broadcast and multicast service (MBMS) efficiently in the network. In synchronous network system, since every cell sends his SCH using shared resource allocation, it is inevitable that two or more neighboring cells can interfere each other in some situation. The cell specific reference signal (CRS) is used for channel estimation in downlink reception. The CRS from neighbor cells may overlap with the resource of PDSCH of the target cell. Hence, the collision of SCH and CRS from the neighbor cells can degrade both the performance of cell search and PDSCH reception at the same time. In this paper, we analyzed the improved performance of the cell search and PDSCH reception by using successive interference cancellation. Simulation results show that the proposed scheme can effectively reduce the mutual interference and improve the performance of the signal detection in view of the cell search and PDSCH reception, respectively.

Single frequency network (SFN) can provide Multimedia Broadcast Multicast Service (MBMS) over a large coverage area, so it receives more and more attention from both academia and industry. However, the application of SFN is still restricted by a large number of feedbacks. Therefore, we propose a novel multicast resource allocation algorithm based on limited feedback scheme. In the algorithm, we first design a user limited feedback scheme based on channel gain threshold to effectively reduce feedback load. The scheme determines to which base stations users should report channel state information. Next, to overcome the MBMS capacity limitation drawback, we encode the MBMS data into a base layer and multiple enhancement layers and develop a joint subcarrier and power allocation strategy to maximize the throughput of enhancement layers while guaranteeing the rate requirement of base layer. Simulation results show that the proposed algorithm significantly reduces 83 % of the feedback overhead while achieving a comparable multicast throughput performance to the case of full feedback.

Confidential authenticated broadcast/multi cast over lossy channels is an important and challenging problem. Applications include the continuous confidential authentication of radio and TV internet broadcast/multicast data distribution by satellite and critical data broadcast in critical tasks (e.g. sensor network for military tasks). Main challenges are authenticity, confidentiality, loss-tolerance, efficiency. Asymmetric cryptography approaches have high security but are expensive in computation and communication. In this paper we propose and prototype a novel loss-tolerance mechanism for lossy channels ensuring authenticity, confidentiality, DoS resistance, efficiency and simplicity. Most applications in practice do not need ideal and perfect real-time task and a minor delay around some seconds is completely acceptable, except a few applications such as safety beacons in VANET. In many applications, such as updating code memory of MANET, delay around some minutes is acceptable, too. Hence, our aim is to provide a robust and dependable loss-tolerant secure broadcast stream at cost of delayed-verification. As an experimental implementation we prototype our proposal in a wireless sensor networks to show its efficiency.

As the utilization efficiency of network resource arouse the interests of researchers, Multimedia Broadcast Multicast Service (MBMS) with its inherent nature brings mobile wireless communications enter a new era. On the other hand, Next Generation Wireless Network (NGWN) trends to integrate multiple Radio Access Technologies (RATs) to optimize the overall network performance. In case, handover performance becomes a vital indicator of mobility experience of User Equipment (UE). Contrast to conventional vertical handover, the problem we facing is how to seamlessly handover for MBMS to provide heterogeneous MBMS (Het-MBMS). In order to address this problem, this paper proposes a new functional entity called Media Independent Broadcast Multicast Service Center (MIBM-SC), by the extensions and enhancements of Broadcast/Multicast-Service Center (BM-SC) and Media Independent Information Service (MIIS). Additionally, a network selection and a cell transmission mode selection schemes are proposed. Both schemes are based on a load-aware network capacity estimation algorithm to select the best target network and the best cell transmission mode. NS-2 based simulation validates that the proposed scheme enables to provide Het-MBMS and it improves the handover performance in terms of packet loss rate, throughput, handover delay, cell load, and bandwidth usage and Peak Signal-to-Noise Ratio (PSNR). Meanwhile, the total consumption of downlink power is reduced.

Device-to-Device (D2D) multicast will become an important technology with the increasing requirements of local communication services in future networks. To increase the overall capacity and improve resource utilization, a novel interference coordination scheme is proposed. The proposed scheme includes three steps. First, in order to mitigate the interference from D2D multicast transmission to cellular networks (CNs), a dynamic power control scheme is proposed that can determine the upper bound of D2D transmitter power based on the location of Base Station and areas of adjacent cells from the coverage area of D2D multicast group. Next, an interference limited area control scheme that reduces the interference from CNs to each D2D multicast receiver is proposed. The proposed scheme does not allow the coexistence of cellular equipments (CUEs) located in the interference limited area to reuse the same resources as the D2D multicast group. Then two resource block (RB) allocation rules are proposed to select the appropriate RBs from a candidate RB set for D2D multicast group. From the simulation results, it is confirmed that the proposed schemes improve the performance of the hybrid system compared to the conventional ways.

Multicast is an efficient way to reduce the required bandwidth of transmitting data simultaneously to a group of users in wireless IPv6 networks. Nevertheless, multicast suffers from two main drawbacks which can be looked from two perspectives, namely security and QoS. With regard to security, the main challenge is to provide security protection to multicast data, which can be achieved by using a secure key management process. Considering a highly dense environment where connection of users to the network is changing frequently due to join or leave operations, key updating approach may burden a network devices with a huge amount of complex encryption/decryption processes. From the QoS perspective, multicast transmission over WLAN offers a tradeoff between the transmission rate and the coverage. The transmission rate of multicast is confined by the user with the lowest data rate in the group which is called fixed base rate problem. To address the above mentioned problems, we propose and implement a lightweight key management and data delivery scheme for multicast over wireless IPv6 networks. The proposed solution is envisaged to reduce the complexity of key updating, while at the same time is able to address the fixed base rate problem. The performance evaluation (by means of analytical and test-bed implementation) of the proposed key management method indicates its efficiency in reducing communication, computation, and storage costs, while maintaining both forward and backward securities. Moreover, the proposed data delivery method is able to improve the throughput and QoS, with low packet loss and transmission delay.

Vehicular Ad Hoc Network (VANET) is an emerging new technology and a promising platform for the intelligent transportation system. The most important application of VANET is disseminating emergency messages to drivers in case of dangerous events. The effectiveness depends on the design of a broadcast scheme. A simple broadcast scheme encounters many problems such as broadcast storm, connection hole, building shadow, and intersection problems. In this paper, we propose an efficient broadcast scheme that simulates water wave propagation to spread emergency messages. This scheme provides warning services with both space and time constraints. Most existing broadcast schemes provide inadequate strategies for limiting the time period of a warning. We verified the performance of our proposed scheme in a simulated street environment with vehicle movements to show the superiority of this scheme in high broadcast coverage areas.

Recently, broadcast/multicast over cellular networks has been actively discussed over commercial wireless mobile terminals. Compared to conventional terrestrial or satellite broadcasting systems, the quality-of-service (QoS) for edge users is an important issue due to inter-cell interference over multi-cell environments. In this paper, we introduce a dynamic bandwidth and carrier allocation (DBCA) technique by fully utilizing different visual importance of each layer in multi-layer video for broadcast/multicast services when the number of users is limited over macro/micro/femto cell environments. To ensure an acceptable video quality for edge users, the bandwidth and the loading ratio are dynamically controlled to enhance the utility through the radio resource control in accordance with the visual importance. The simulation results show that DBCA exhibits much better QoS by sending visually more important data with high priority in the cell border region.

Mobile multicast is based on the traditional multicast protocols and the mobility support protocols to provide the multicast services for the mobile subscribers. Several mobile multicast methods were proposed in the past few years, but most of them are based on Mobile IPv6 and its variants which require the mobile node to support the mobility function. Recently, Proxy Mobile IPv6 (PMIPv6) was proposed to provide the mobility support for the mobile node with or without mobility function, and the previous studies have shown that PMIPv6 can improve the performance in term of the handover performance and protocol cost. However, PMIPv6 mainly concerns on the mobility support for unicast routing and little considers the multicast routing. In this paper, we propose two multicast methods called the MAG (Mobile Access Gateway)-based method and LMA (Local Mobility Anchor)-based method based on the different multicast delivery transmission path to extend PMIPv6, and analyze their performance under the different scenarios. The analytical results show that the LMA-based method is suitable for the higher speed, bigger domain size, and larger network topology scenarios, whereas the MAG-based method is suitable for the lower speed, smaller domain size and smaller network topology scenarios.

This paper considers the problem of opportunistic multicast scheduling in wireless time-division multiplexing systems with adaptive modulation and channel coding. The problem is first formulated and an effective scheduling scheme is proposed to maximize the multicast throughput while a desired packet error rate is guaranteed. The proposed scheme dynamically selects multicast rates by considering the configuration of the multicast group and instantaneous network states, and thus it can adapt well to network conditions. Extensive simulation results conclusively demonstrate that, compared to the worst-user multicast scheduling, the proposed approach can increase the wireless channel efficiency by large margins, especially when the channel is operating in a lower signal-to-noise ratio region and/or when the multicast group size increases. Besides, the simulations show that the proposed approach can work well in systems with imperfect channel estimation.

In mobile networks, the provision of rich multimedia services, such as Mobile TV, is considered of key importance. To this end, Multimedia Broadcast/Multicast Service (MBMS)--that was introduced in the Release 6 of Universal Mobile Telecommunication System (UMTS)--is envisaged to play an instrumental role in the proliferation of mobile market. The reason behind the design of MBMS was the need to provide multiple users with the same data at the same time in 3GPP (3rd Generation Partnership Project) cellular networks. Still, MBMS performance is limited by the base stations' transmission power. As an aftermath, efficient power allocation techniques should be implemented so as to ensure the mass provision of multimedia applications to mobile users. This paper proposes a novel mechanism for efficient radio bearer selection during MBMS transmissions. The proposed mechanism is based on the concept of transport channels combination in any cell of the network. Furthermore, the mechanism exploits the performance enhancements emerged from Multiple Input Multiple Output (MIMO) antennas and manages to efficiently deliver multiple MBMS sessions. The proposed mechanism is thoroughly evaluated and compared with the radio bearer selection mechanisms proposed by 3GPP.

The problem of providing an efficient and low-cost video streaming service over wireless access networks is considered in this work. In order to tackle the "last mile" bottleneck for video delivery to the home, we propose a content-aware architecture, that incorporates popularity-dependent video patching with application-enabled multicast content delivery. The key idea is to exploit the Broadcast/Multicast Service Center (BM-SC) in Universal Mobile Telecommunications System (UMTS) networks, by forwarding individual requests for popular data to the BM-SC, and then to serve these requests efficiently by multicast content distribution. The proposed method offers a tremendous bandwidth saving, in comparison with the MAC-enabled multicasting currently exists in wireless networks. We analyze the conditions under which multicast content delivery offers a better QoS, in terms of service delay, over the individual service currently used for video streaming.

We propose and analyze a regional registration based mobile multicast service management scheme which we call URRMoM for efficiently supporting mobile multicast in Mobile IP networks. URRMoM extends the design concept of Remote Subscription (RS) by using mobile multicast agents (MMAs), each covering a number of MHs in its service area through tunneling multicast packets received from the multicast source to them. URRMoM adopts a user-central design allowing each mobile host to determine its optimal MMA service area dynamically depending on its service and mobility characteristics. We develop an analytical model to describe the behavior of a MH operating under URRMoM and derive the optimal service area of the MMA based on the MH's service and mobility characteristics to minimize the total network traffic generated due to multicast packet delivery and multicast tree maintenance. We present analytical results validated by simulation to demonstrate the benefit of our proposed regional registration based mobile multicast service management scheme over existing schemes including RS and RBMoM.

Focusing on enriched multimedia broadcast/multicast opportunities of a wireless communication network, we build multicast cell configurations in a CDMA based network. In a CDMA based wireless network, a terminal can get significant signal quality enhancement by the combining of data streams from multiple base stations. To combine the data streams, the base stations have to be operated with a common time schedule. The cells whose base stations are operated as such are called soft-combine cells. A terminal can take advantage of signal quality enhancement, if the terminal is in a soft-combine cell and at least one neighbor cell supports soft-combine. Our problem is to find a limited number of soft-combine cells under the computing burden of the network controller, while the benefit of soft-combine is maximized. We build a combinatorial optimization model and solution methods for the dynamic reconfigurations of soft-combine supporting cells.

Multimedia Broadcast Multicast Service (MBMS) in Wideband Code Division Multiple Access (WCDMA) networks is used to transmit information from one source to vast amount of recipients. The MBMS technique eases the load of the network and therefore allows network to serve more subscribers. The very aim of this study is to evaluate the performance of Release 6 MBMS and its performance enhancements in WCDMA networks. Special attention will be focused on macro and receive diversity which are considered in addition to time diversity provided by long interleaving as enhancements on MBMS performance. 3GPP Release 6 specifications for MBMS introduce two macro diversity schemes: soft and selective combining. The effect of those combining scheme concepts together with and without receive diversity provided by multiple receive antennas are examined. Also, a concept closely related to the receive diversity called Rx-switching i.e., turning the another receive antenna off in good channel situations for power saving purposes is studied. The system level performance of MBMS point-to-multipoint (p-t-m) mode is evaluated with dynamic system level tool in which e.g., mobility of users and interactions of the radio resource management functionalities are explicitly taken into account. Our studies indicate that macro diversity brings significant gains to the MBMS performance. Receive diversity together with macro diversity schemes improves the performance even more and therefore enhances the cell throughput that MBMS can offer. Furthermore, based on the findings of this study it seems that 2Rx Rake receiver can operate with a single antenna significant amount of time without sacrificing desired coverage and thus provide clear power saving opportunities.

In this paper we consider the use of hierarchical Quadrature Amplitude Modulation (QAM) constellations for Multimedia Broadcast/Multicast Service (MBMS) within Wideband Code Division Multiple Access (WCDMA) based systems. These constellations are employed so as to increase the transmission efficiency, since they are able to provide unequal error protection to different information bit streams. With this strategy, the most important information can be received by all users while the less relevant information will only be extracted by users with good propagation conditions. However, these constellations are very sensitive to inter-symbolic interference introduced by multipath propagation, especially for large constellations. Moreover, large hierarchical constellations have also high channel estimation requirements. For these reasons, we propose an iterative receiver for joint detection and channel estimation. The proposed receiver takes advantage of the turbo-code present in the transmission system and uses feedback information from the turbo-decoder to estimate and suppress the interference, as well as to provide enhanced channel estimates.

In this paper, we present an efficient scheme for the multicast transmission of the data in the Universal Mobile Telecommunications System (UMTS). We take advantage of the tree topology of the examined network and we introduce the use of Routing Lists (RLs) in the nodes of the UMTS. The adoption of these lists leads to the decrement of the transmitted packets and to the efficient use of network resources in the multicast transmission of the data. We describe in detail the appropriate steps for the successful multicast transfer of data. Furthermore, we analyze the handling of special cases such as user mobility scenarios. Especially, the various handover types are examined along with the Serving Radio Network Subsystem relocation procedure. Finally, we implement our approach in the NS-2 simulator and we present the performance of the multicast mechanism.

Broadcast and multicast offer a significant improvement of spectrum utilization, and becomes particularly important where information channels are shared among several users. Mobile cellular environments are expected to evolve with the technological approaches necessary to facilitate the deployment of multimedia services, such as streaming, file download and carousel services. The perspective that video streaming in wireless networks services is an attractive service to end-users has spurred the research in this area. To provide for a video delivery platform in UMTS, the Third Generation Partnership Project (3GPP) addressed this problem with the introduction of the Multimedia Broadcast and Multicast Services (MBMS) in 3GPP Release 6. In this document we analyse several effective radio resource management techniques to provide MBMS, namely, use of non-uniform QAM constellations, multi-code and macro-diversity to guarantee the optimal distribution of QoS depending on the location of mobiles.

This paper proposes a fast handover mechanism to provide a seamless multicast service for Mobile IPv6 hosts. With the proposed Fast handover based on a Mobile IP-Multi casting (FMIP-M) protocol, the selection of a new multicast service method, service preparation, and initialization procedures are all performed during the fast handover period, thereby enabling a reliable and efficient multicast service. When mobile hosts move to other networks, they can encounter data loss, out-of-synch problems for multicast data, and multicast service exchange latency. Therefore, the proposed FMIP-M allows the new access router to select a suitable multicast service method according to the multicast service-related network conditions and supports a reliable multicast transmission by compensating for data losses from the previous access router. An analysis is conducted of the overheads associated with a fast multicast handover, including the signaling cost and multicast packet-forwarding cost, where the costs are formulated based on timing diagrams, and compared with a fast handover using Mobile IPv6. The performance analysis and numerical results confirm that the proposed FMIP-M provides a fast multicast handover and reliable service with a relatively small signaling cost and packet-delivery cost.

MIMO systems promise high performance gains over conventional single antenna systems. To accomplish high data rates over wireless links the use of multiple transmit and receive antennas is an alternative that does not require any extra bandwidth. It has the potential to address the unprecedented demand for wireless services, particularly for the Multimedia Broadcast Multicast Service (MBMS). This service supports downlink streaming and download-and-play type services to large groups of users. From the radio perspective, MBMS includes point-to-point (PtP) and point-to-multipoint (PtM) modes. New proposed MBMS related enhancements in the physical layer specifications and their effects on resource requirements are presented in this paper, such as the use of High Speed Downlink Packet Access (HSDPA) to broadcast/multicast video streaming using the Deficit Round Robin (DRR) scheduler algorithm as a way to maintain an acceptable QoS for all the users. Other improvements, based on the use of MIMO including macro-diversity, are independent of the mode used and are dependent on deployment scenarios, but can yield substantial reduction in resource demand.

New-generation telecommunications systems are expected to meet the rising user exigencies of mobility and ubiquitous access to multimedia services. As a consequence, 3GPP consortium has introduced the Multimedia Broadcast and Multicast Service (MBMS) concept into 3G/beyond-3G networks. Supporting MBMS in next generation hybrid wireless platforms becomes a challenging issue due to high traffic load deriving from both signaling message exchange and data transmission between multicast sources (BM-SC) and end users. Therefore, in this context, key research issues are surely: effective exploitation of the limited radio spectrums available, coordination of users accessing radio resources, as well as provisioning of desired QoS guarantees. Given the high mobility profiles typical of UMTS users, it clearly appears that the cited target performance can only be achieved through networking solutions based on an overlapped terrestrial-HAP-satellite coverage. An inter-working scenario where HAPs operate in synergy with the UMTS terrestrial and satellite segments seems to be the most promising solution to provide mobile users with MBMS services. Our work, dealing with architectural design options, takes into account many metrics relevant to aspects, such as: frequency allocation, costs in terms of resource utilization, signaling traffic load, number and location of customers, reliability, possible retransmission paths, user mobility, and QoS.

The demand of the new telecom industry for cost efficient provision of mobile multimedia services is faced with the reality of scarce radio resources. The requirement of spectrum efficiency has driven the development of various digital radio technologies that have been optimized for specific services, namely for broadcast or for mobile communication. However, existing and emerging multimedia services exhibit challenging requirements in terms of asymmetry, interactivity, real-time, and multicast communication. This paper describes an IP based multi-radio infrastructure that enables the co-operation of existing radio networks to combine their capabilities to ensure a spectrum efficient provision of high-quality mobile multimedia services. Further the need for a dynamic allocation of spectrum to radio services is motivated. The basic functionality and the architecture of a multi-radio system is outlined, with a special emphasis on the cooperation between different radio systems. Further an evolution path for the convergence of broadcast and new telecom is desribed, starting from today's systems and leading to a fully coordinated system.