Reliable Mobile Multicast Research Articles

Hierarchical agent-based secure and reliable multicast in wireless mesh networks

We propose and analyze a hierarchical agent-based secure and reliable multicast (HASRM) algorithm for efficiently supporting secure and reliable mobile multicast in wireless mesh networks, with design considerations given to minimize the overall network cost incurred by reliable multicast packet delivery, mobility management, security key management, and group membership maintenance. HASRM dynamically maintains a group of multicast agents running on mesh routers for integrated mobility and multicast service management and leverages a hierarchical multicast structure for secure and reliable multicast data delivery. The regional service size of each multicast agent is a key design parameter. We show via model-based performance analysis and simulation validation that there exists an optimal regional service size that minimizes the overall communication cost and the optimal regional service size can be dynamically determined. We demonstrate that HASRM under optimal settings significantly outperforms traditional algorithms based on shortest-path multicast trees extended with user mobility, security, and reliability support. We also show that a variant of HASRM is superior to a recently proposed multicast algorithm for secure group communication in wireless mesh networks.

An Analysis Comparison of Reliability Mechanisms for Improving Reliable Mobile Multicast Protocols

Existing reliable multicast protocols are designed to perform well in wired networking environments. However, in mobile networking environments, these reliable mobile multicast protocols are not optimal as they do not take into account the limitations of power (energy), storage capacity, processing power, impairments of wireless communication channels, and the frequent changes of location and the resulting loss of network connectivity. This paper analyses four hybrid reliable multicast schemes, namely NAK-based schemes, ACK-based schemes, ACK-based schemes with FEC (Forward Error Correction), and NAK-based schemes with FEC that are suitable for mobile networking environments and quantifies their performance. These four schemes differ from the generic sender-initiated and receiver-initiated reliable multicast protocols in that they rely on a mixture of multicasting and unicasting for providing reliability. This analysis is used to show that NAK-based schemes with FEC is best suited for reliable multicasting in mobile environments as they provide excellent performance in terms of average wireless channel utilization and average processing time, independently of the number of MHs.

Dynamic retransmission control for reliable mobile multicast

Most existing multicast protocols adopt a static retransmission scheme (unicast or multicast) to retransmit lost packets. In the mobile multicast environment, static multicast retransmission mode may lead to congestion in the receivers' wireless interfaces, while static unicast mode may result in great network load. Both static unicast and multicast retransmission modes will cause a performance loss. This paper logically divides the mobile multicast network into fixed and mobile parts, and focuses on the mobile part. Then this paper analyzes the retransmission costs when multicast or unicast mode is chosen. Two main parameters are used to compare their efficiencies: the average air-interface utilization of each receiver and the average network load. Based on the results of analysis, two new algorithms, called NLPA (Network Load Priority Algorithm) and AUPA (Air-interface Utilization Priority Algorithm) are presented. Finally, simulation results conclude that, with proper parameters, both NLPA and AUPA can dynamically alternate between unicast and multicast retransmission modes according to the conditions of network and receiver, and avoid congestion in receivers' wireless interfaces as well as great network load, with a better use of network and terminal resources.

Performance Analysis of a Multicast Protocol for Wireless Environments

This paper presents a performance study, using both analytical modeling and simulation techniques, of a new end-to-end reliable multicast protocol for use in environments with wireless access. The proposed pro tocol, called the reliable mobile multicast protocol (RM2), divides a multicast tree into sub-trees where subcasting is applied within the relatively smaller regions using a hierarchical tree of retransmission servers (RSs). RM2 is receiver-oriented in that the transmitter does not need to know its receivers, hence offering better scalability. The Internet Group Management Protocol is used to manage group membership whereas the IETF's Mobile IP offers support to user mobility through a temporary IP address. Each RS has a retransmission subcast ad dress shared by its members which may be dynamically configured using allocation schemes such as the IETF's MADCAP. More important, RM2 uses a dynamic re transmission strategy to switch between multicast and unicast retransmission modes according to the amount of extra load generated in the network and in the wire less interfaces by packet retransmissions. It is shown through analytical modeling and simulation that RM2's dynamic adaptation is not only important but also necessary when considering mobile wireless access.