NTT DoCoMo

About: NTT DoCoMo is a based out in . It is known for research contribution in the topics: Base station & Mobile station. The organization has 4032 authors who have published 8655 publications receiving 160533 citations.

Communication terminal and retransmission control method

Abstract: A retransmission control method of the present invention includes the steps in which a receiving terminal measures a round trip time between the receiving terminal (3a) and a sending terminal (1); calculates a retransmission time out RTO by using the measured RTT; and starts a time counting operation of the RTO upon reception from a point in time when a segment is received from the sending terminal (1); transmits a segment prompt signal which prompts the sending terminal (1) to transmit a segment, when the segment is not received from the sending terminal until the RTO is completed, and in which the sending terminal (1) retransmits a segment to the receiving terminal when there is a segment to be retransmitted; and transmits a data-less signal to the receiving terminal (3a) when there is a segment that should be retransmitted, the data-less signal indicating that there is no segment that should be retransmitted.

On Minimizing Base Station Power Consumption

Abstract: We consider resource allocation over a wireless downlink where Base Station (BS) power consumption is minimized while upholding a set of required link rates. A Power and Resource Allocation Including Sleep (PRAIS) method is proposed that combines resource sharing, Power Control (PC), and Discontinuous Transmission (DTX), such that downlink power consumption is minimized, which can be formed into a convex optimization problem. Unlike conventional approaches that aim at minimizing transmit power, in this work the BS mains supply power is chosen as the relevant metric. Based on a linear power model, which maps a certain transmit power to the necessary mains supply power, we quantify the fundamental limits of PRAIS in terms of achievable BS power savings. The fundamental limits are numerically evaluated on link level for four sets of BS power model parameters representative of envisaged future hardware developments. We establish an expected lower limit for PRAIS of 27W to 68W depending on load per link for BSs installed in 2014, which provides a 61% to 34% gain over conventional resource allocation schemes.

Transmission power control apparatus and method in a mobile communication system, mobile station, and communication apparatus

Abstract: A transmission power control apparatus includes propagation loss calculation means for calculating propagation loss in a radio wave propagation path between a mobile station and each of base stations. Transmission power control information to be used for transmission power control of a mobile station is decided according to transmission power control information from a base station obtained at a mobile station and the propagation loss of the radio wave propagation path between each base station and a mobile station. When a reception signal quality is decided to have been lowered than a predetermined quality, an autonomous control procedure functions so that the transmission power is increased according to a predetermined characteristic independently of transmission power control information from another communication apparatus. After synchronization is established in a mobile station for a signal from a base station, the transmission power is controlled from the initial value according to a predetermined characteristic independently of the transmission power control information from the base station.

Mobile communication system, line concentrator, radio base station, mobile station, and communication method

Abstract: A mobile-communications system is disclosed. The system includes a mobile station, a wireless-base station enabled to communicate with the mobile station, and a location-information management apparatus for managing a state of the mobile station in a network layer upper to a link layer for managing wireless-communications resources. The mobile station is provided with wireless-communications means for transmitting and receiving a signal with the wireless-base station in an active state in the link layer for managing the wireless-communications resources, discontinuous-receiving means for discontinuously receiving a control signal from the wireless-base station in the link layer in a state different from the active state, and state-management means for creating a state-transition signal in response to a paging signal included in the control signal.

Running state migration of platform specific graphical user interface widgets between heterogeneous device platforms

Abstract: A scaleable graphical user interface system for migrating the running state of graphical user interface widgets between heterogeneous device platforms includes a platform independent presentation model. The current running state of a first platform specific presentation operating on a first heterogeneous device platform may update the running state of the platform independent presentation model. The platform independent presentation model may be customized to generate a second platform specific presentation for a second heterogeneous device platform. The running state of the platform independent presentation module may be applied to the second platform specific presentation module to implement the current running state from the first heterogeneous device platform on the second heterogeneous device platform.