Masato Okuda

Centralized mobility load balancing scheme in LTE systems

MLB (Mobility Load Balancing) is one of the use cases of SON (Self-Organizing Network) discussed in NGMN and 3GPP. The objective of MLB is to reduce the number of low throughput users and the call blocking rate, when cell loads such as radio resources are unbalanced among cells, by adjusting handover parameters. In this paper, we focus on adjusting the HO margin which is one of the handover parameters and propose a centralized solution for MLB where a central server decides optimal HO margins considering load distribution among cells. In addition, we also present simulations results to demonstrate that our proposed solution reduces the number of low throughput users compared with a distributed solution.

Asynchronous Transfer Mode (ATM)-based access network with multicast function for multimedia services

We categorize broadband multimedia services according to their required bit rates and their transport symmetries. We also describe typical access networks, their service coverages and migrations. According to our analysis, we propose ATM-based Multimedia Information and Communication System (AMICS) as an ATM based multimedia multi-service platform. AMICS consists of ATM backbone networks, ATM ring regional transport networks, and ATM access networks. The access network has an active double star configuration and provides multicast/statistical multiplexing functions. The multicast function in AMICS is evaluated using near-video-on-demand and CATV service simulations.

Modeling and evaluation of broadband access networks for multimedia services

We categorize broadband multimedia services and typical access networks, and describe the service coverage of each access network. According to our analysis, we claim that ATM-based access networks are suitable for use in the future information infrastructures. The ATM-based access network is evaluated by its multicast function using near-video-on-demand and CATV service simulations.<<ETX>>

Analysis of ABR behavior over ATM-based broadband access networks

There has been an enormous growth in the popularity of the Internet. The provisions of access to the Internet will be one of the principal services of the next generation of access networks. In order to provide cost effective Internet access over ATM-based broadband access networks, the introduction of an available bit rate (ABR) service class is a promising solution. This paper describes our analysis of the ABR behavior over ATM based access networks focusing on explicit-rate-based rate controls and their round-trip time effects. We also describe the hardware implementation of the ABR-based rate controls.