In this paper, we study multi-layer transmission for wireless multimedia multicast in a cell. Under the assumptions that the users in a cell are uniformly well distributed and that the BS has no channel side information, we find the optimal number of transmission layers and power allocation. This result can be used in highly dynamic dense networks and jamming networks where channel side information at the transmitter is somewhat useless.

In this work, we propose a delayed data forwarding scheme using delay function. According to the link status and network topology, each node gives arrived packets some delay before forwarding them so that the packet flows through the most stable route. We first propose conservative delay function from strict end-to-end delay bound and then relax it more and more and finally introduce a SNR based delay function using cross-layer concept between link layer and network layer. We show its performance by some analysis and simulation in mesh networks. This scheme is useful for stable data routing in highly dynamic networks.

This paper proposes a new on-demand routing protocol. It aims to establish a redundant route path containing intermediate nodes having relatively more synchronized neighbor nodes in a possible route. This approach can localize the effects of route failures and reduce route reconfiguration time by enhancing the reachability to the destination node without source-initiated route re-discoveries at route failures. Simulation results show that it has better performance than AODV and TORA.

In this paper, we propose the high-level service architecture supporting multimedia multicast. The proposed architecture specifies network-oriented and lightweight communication management, which includes group management, multiparty call control and multicast connection/multiple connections control. Many of the existing approaches handling multimedia multicast applications are dependent on specific transport technologies, such as the Internet and ATM, and lack effective communication management. On the other hand, our approach defines flexible and extensible communication management that can be applied to a variety of multimedia multicast applications, independently of transport technologies. Our architecture supports the separation of control from a terminal, which enables remote control and control mobility, so that a user can use a multicast service in a more various way. The architecture is overlaid above legacy transport networks so that the existing network protocols are used for connection control. This minimizes the modification to a legacy transport network and enhances the practicality of the architecture. In addition, terminal manager and virtual device concepts are introduced that hide the details of physical devices from an application designer. The architecture consists of several service components that effectively interact with each other on a distributed platform. To verify and evaluate our architecture, we have prototyped the high-level service architecture on a CORBA platform and analyzed the architecture using a simulation.

In heterogeneous cellular networks (HCN), which consists of macrocells and picocells, efficient interference management schemes between macrocells and picocells are crucial to the overall system performance. We propose a dynamic cooperative silencing (DCS) scheme for intercell interference control (ICIC). It is a low-complexity, low-feedback and distributed algorithm using only strongly interfered neighboring user information. A system simulation shows that the system performance and in particular the cell-edge throughput is significantly increased with the proposed silencing scheme.

In heterogeneous cellular networks (HCN), which consists of macrocells and numerous femtocells, efficient interference management schemes between macrocells and femtocells are so crucial to the overall system performance. To mitigate intercell interference in HCN, we propose a new rate-split transmission scheme which has the following characteristics. First, it supports user quality of service (QoS) with the least intercell interference. Second, it is a low complexity and distributed scheme using only Interference to Signal and Noise Ratio (ISNR). An evaluation confirms that the proposed scheme offers better performance than legacy schemes which are not considering user QoS.