Tatsuhiro Chiba

Learn More
Localized mobility protocols are designed to address many of the drawbacks such as additional signaling and over-the-air tunnel overhead associated with global mobility protocols like Mobile IPv4 and Mobile IPv6. Proxy Mobile IPv6 is one such network controlled localized protocol defined in the IETF Although Proxy Mobile IPv6 can resolve longer binding(More)
Seamless mobility support in a heterogeneous roaming environment poses several challenging issues in the choice of network architecture design and mobility protocol. Several standards organizations are designing next generation wireless network architectures with a suite of new network elements and protocols that provide service continuity for intra-and(More)
Data-intensive parallel applications on clouds need to deploy large data sets from the cloud's storage facility to all compute nodes as fast as possible. Many multicast algorithms have been proposed for clusters and grid environments. The most common approach is to construct one or more spanning trees based on the network topology and network monitoring(More)
In an effort to provide seamless mobility support in IMS/MMD networks, operators need to choose a specific IP- based mobility protocol. However, there are several micro- and macro-mobility protocols available that the operators can choose from. Operators often face the challenges of selecting the appropriate mobility protocol that can provide the most cost(More)
The performance of MPI collective operations, such as broadcast and reduction, is heavily affected by network topologies, especially in grid environments. Many techniques to construct efficient broadcast trees have been proposed for grids. On the other hand, recent high performance computing nodes are often equipped with multi-lane network interface cards(More)
Advances to IMS (A-IMS) architecture extends the existing IMS/MMD architecture currently being defined in 3GPP/3GPP2 respectively so that it can support both SIP and non-SIP-based services. We describe the key strength of A-IMS architecture, compare the benefits over MMD architecture, and then describe an enhanced MMD experimental testbed to demonstrate(More)
IPv6 Networks A. Dutta, S. Das, Telcordia Technologies, NJ T. Chiba, H. Yokota, A. Idoue, KDDI Labs, Japan K. D Wong, Malaysia University of Science and Technology H. Schulzrinne, Columbia University, NY Abstract: In order to provide seamless connectivity to the roaming users several mobility protocols have been developed at different layers. All of these(More)
Besides being an in-memory-oriented computing framework, Spark runs on top of Java Virtual Machines (JVMs), so JVM parameters must be tuned to improve Spark application performance. Misconfigured parameters and settings degrade performance. For example, using Java heaps that are too large often causes a long garbage collection pause time, which accounts for(More)
In recent years, IMS/MMD architectures have been gaining importance as the key technologies for the Next Generation Network, which is standardized by ITU-T. These architectures utilize SIP for session management and, in particular, MMD utilizes Mobile IP for mobility support of mobile nodes. When both protocols are used at the same time, the problem of(More)
There are demands for alerts that use the results of intensive data analysis, such as relationships among events generated by many vehicles over a large area. These alerts require data analysis on servers. However, when a server receives massive amounts of data from vehicles, the processing latency increases because of the communication delays between the(More)
  • 1