Nippon Telegraph and Telephone Corporation

Kei Takeshita

Taichi Kawano

Hiroshi Yamamoto

Kazumichi Sato

Masahiro Yokota

Takuto Kimura

Ken Nishimatsu

A quality-of-experience optimization system configured to optimize quality (QoE: Quality of Experience) that a user experiences in a content distribution service, including: a recommend request apparatus configured to output a distribution parameter candidate of content distribution for optimizing QoE of content distribution, and to receive a distribution parameter for optimizing the QoE as a recommend value; and a quality-of-experience optimization apparatus configured to estimate QoE from the distribution parameter candidate received from the recommend request apparatus, and to calculate a distribution parameter for optimizing the QoE as a recommend value to output the recommend value.

Quality-of-experience optimization system, quality-of-experience optimization apparatus, recommend request apparatus, quality-of-experience optimization method, recommend request method, and program

A communication-speed-limited user extraction apparatus for extracting a user whose communication speed is limited based on communication histories includes a communication history storage unit configured to store the communication histories including throughput information on a user-by-user basis; and a communication-speed-limited user determination unit configured to extract a communication history with a same communication environment at a communication date and time within a predetermined period of time from the communication history storage unit and determine that a user with a different throughput distribution is the user whose communication speed is limited.

Communication-speed-limited user extraction apparatus, throughput estimation apparatus, communication-speed-limited user extraction method, throughput estimation method, communication-speed-limited user extraction program, and throughput estimation program

A delivery rate selection device, for selecting a delivery rate when delivering a video image from a video delivery server to a client in a video delivery service. When a delivery rate calculating unit receives from an inquiry source an inquiry of delivery rate for delivering a video image to a given user, a delivery rate calculating unit acquires presence or absence of a playback stall tolerance and presence or absence of an image quality deterioration tolerance of the given user from the user characteristic storage unit, selects an encoding rate from a plurality of encoding rates of the video image according to a combination of the presence or absence of a playback stall tolerance and the presence or absence of an image quality deterioration tolerance of the given user, and returns the selected encoding rate as the delivery rate to the inquiry source.

Delivery rate selection device, delivery rate selection method, and program

A communication speed estimation apparatus configured: to generate communication log information representing history of communication executed by a user, and store the communication log information in a communication history information storage unit; to calculate, based on the stored communication log information, throughput result information for each of a server, a network, and a user terminal that were used for the communication for each time slot, and store the calculated throughput result information in a quality information storage unit; and, when the user performs new communication, in advance, to read out corresponding throughput result information from the quality information storage unit based on at least one of a terminal, a server, and a network that the user intends to use, and a time slot including a time when the user intends to perform communication, and to estimate a communication speed in the new communication based on the read-out throughput result information.

Communication speed estimation apparatus, communication speed estimation method, and program

A moving-image parameter selection device includes a storage unit configured, for each distribution of a video in a past, to associate a combination of values of moving-image parameters used for the distribution, with a KPI related to the distribution, to store the associated combination; and a selector configured, for each of the combinations, to calculate an average of the KPI, to execute a significance test for each of the averages of the KPIs with respect to one of the averages of the KPIs of the combinations, and based on results of the significance tests, to select a part of combinations among the combinations, and thereby, enables selection of moving-image parameters that contribute to increasing the profit of a video distribution service.

Moving-image parameter selection device, moving-image parameter selection method, and program

A video quality estimation apparatus used for an encoded video, to estimate a video quality value being a value quantifying a video quality being quality of the video felt by a user when viewing and listening to the video. The apparatus includes a maximum value calculator to calculate a maximum value of the video quality value from a resolution of the video and a frame rate of the video, and a video quality calculator to calculate an estimated video quality value corresponding to an encoding bit rate having been input, based on a predetermined relationship between the encoding bit rate of the video and the video quality value. The predetermined relationship is a relationship in which the video quality value increases while the encoding bit rate increases, and the video quality value converges on the maximum value calculated by the maximum value calculator.

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Musashino, Japan

Kei Takeshita