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.

Location privacy for internet protocol networks using cryptographically protected prefixes

Abstract: Cryptographically Protected Prefixes (“CPPs”) are used to create IP addresses, preventing any correlation between a CPP IP address and a host's geographic location. An IP address is subdivided into address prefixes of multiple segments. Each segment is encrypted with a cryptographic key known only to a subset of routers in the access network domain (or Privacy Domain). Therefore, each router obtains the information it needs to forward a packet of information, but not any additional information.

Roadmap of IMT-advanced development

Abstract: The WRC-07 decisions have paved the way toward the development of IMT-advanced by identifying a 200-MHz contiguous spectrum above 3 GHz for a number of countries. It is also noted that for early implementation of IMT-advanced there are technical subjects to be studied and solved, in particular for compatible operation with other systems sharing the same frequency bands. For the standardization activities, global cooperation between ITU-R and other organizations are required.

Method and apparatus of dynamic spectrum allocation in coexisting heterogeneous wireless networks

Abstract: Embodiments of this disclosure include a method and apparatus of dynamic spectrum allocation in coexisting heterogeneous wireless networks. A Mobile Station (MS) detects its own serving Access Point (AP) and a coexisting AP (cAP) of the serving AP, sends to the serving AP a service request message carrying a bandwidth demand and a cAP ID. The serving AP sends to a Dynamic Spectrum Allocation Module (DSAM) a spectrum request message carrying its own AP ID, the cAP ID and the spectrum demand. The DSAM allocates the spectrum dynamically using a dynamic spectrum allocation algorithm according to the spectrum demand, AP ID and cAP ID, and sends a spectrum allocation result to the serving AP, which allocates an appropriate bandwidth to the MS according to the spectrum allocation result. Thus, sharing spectrum dynamically between multiple coexisting wireless networks can be achieved, and spectrum utilization can be improved.

Transmission apparatus, transmission method, reception apparatus and reception method

Abstract: A disclosed transmission apparatus includes a multiplexing portion that multiplexes a common pilot channel, a shared control channel, and a shared data channel; a symbol generation portion that performs an inverse Fourier transformation on the multiplexed signal so as to generate a symbol; and a transmission portion that transmits the generated symbol. The multiplexing portion multiplexes the shared control channel including control information necessary for demodulation of the shared data channel including a payload and the common pilot channel to be used by plural users in a frequency direction, and the shared data channel in a time direction with respect to the common pilot channel and the shared control channel. Even when the number of symbols composing a transmission time interval (TTI) is reduced, transmission efficiency of channels excluding the common pilot channel can be maintained by reducing insertion intervals of the common pilot channel accordingly.

Image predictive encoding device, image predictive encoding method, image predictive encoding program, image predictive decoding device, image predictive decoding method, and image predictive decoding program

Abstract: An image predictive encoding device can efficiently encode an image, while suppressing an increase in prediction information and reducing the prediction error of a target block. In an image predictive encoding device according to one embodiment, to produce a prediction signal of a partition in a target region, it is decided whether prediction information of a neighbouring region can be used. When prediction information of the neighbouring region can be used, a region width of the partition where the prediction information of the neighbouring region is used to produce the prediction signal is determined. The prediction signal of the target region is produced from a reconstructed signal based on the prediction information of the target region, the prediction information of the neighbouring region, and the region width. The prediction information, information identifying the region width, and a residual signal between the prediction signal and an original signal of the target region are encoded.