Kazutaka Murakami

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In self-healing networks, end-to-end restoration schemes have been considered more advantageous than line restoration schemes because of a possible cost reduction of the total capacity to construct a fully restorable network. This paper clarifies the benefit of end-to-end restoration schemes quantitatively through a comparative analysis of the minimum link(More)
—Internet telephony is viewed as an emerging technology not only for wireline networks, but also for third generation wireless networks. Although IP end-to-end is considered the ultimate approach for future wireless voice services, there is still a long way to go before IP voice packets can be effectively transported over the air. Therefore, Internet(More)
Internet telephony and mobile telephony are both growing very rapidly. Directly interworking the two presents significant advantages over connecting them through an intermediate PSTN link. We propose three novel schemes for the most complex aspect of the interworking: call delivery from an Internet telephony (SIP) terminal to a mobile telephony (UMTS)(More)
Seamless roaming in heterogeneous circuit-switched and IP networks is key for successful migration towards all-IP. The Unified Mobility Manager (UMM) keeps track of users' locations whatever network they are roaming, and that routes calls from any originating to any terminating network. In a UMM enabled network, calls are addressed to users and dynamically(More)
Next generation wireless networks will rely heavily on packet transport for both data and voice services. In this paper, we describe the Router for Integrated Mobile Access (RIMA) system, which is the core network element of an integrated wireless packet network. RIMA acts as a Mobile Switching Center for standard cellular telephony users, and a mobile(More)