*1 “Xi” (Crossy): “Xi” (read “Crossy”) and its logo are trademarks of NTT DOCOMO. *2 OFDMA: A radio access scheme that uses Orthogonal Frequency Division Multiplexing (OFDM). OFDM uses multiple low data rate multi-carrier signals for the parallel transmission of wideband data with a high data rate, thereby implementing high-quality transmission that is highly robust to multipath (see *3) interf...

Many wireless sensor networks must sustain long lifetimes on limited energy resources. Two major approaches, transmission power control and sleep scheduling, have been proposed to reduce the radio power consumption in the transmission state and the idle state, respectively. In this paper, we first review existing transmission power control and sleep scheduling approaches and then describe a Uni...

Mobile users are facing the fact that many heterogenous radio access technologies coexist, ranging from wireless LANs to cellular systems. No technology has emerged as a common and universal solution which makes the current trends today toward the design of AllIP wireless networks, where radio cells are under the control of IP Access Routers for signalling and data transmission. In such network...

Mobile users are facing the fact that many heterogenous radio access technologies coexist, ranging from wireless LANs to cellular systems. No technology has emerged as common and universal solution which makes the current trends today toward design of All-IP wireless networks, where radio cells are under the control of IP Access Routers for signalling and data transmission. In such as networks,...