8 results about "Round-trip delay time" patented technology

A work load of a web server that is caused by sequence of requests sent by one or more client devices is reduced by blocking (such as discarding, delaying, or dropping) part of, or whole of, the requests in the sequence, so that the one or more client devices are not identified as causing a Denial- of-Service (DoS) attack or Distributed Denial-of-Service attack (DDoS attack). The blocking may be in response to metering, continuously or periodically, of a Round-Trip delay Time (RTT) to the web server, or metering a feature or amount of the sent sequence of requests, the received responses therefrom, or any combination thereof. The blocking may be in response to comparing the metered value to a threshold, or in response to a correlation between the metered values, where the blocking is performed in response to the metered value being above the threshold. The process may be repeated.

A communication device or the like capable of converging a transmission rate to an available bandwidth even in an environment where feedback delay is large. [Solution] A communications device comprising: a convergence determination means for determining whether the transmission rate has converged to a certain bandwidth using time series data indicating the time series progression of the data transmission rate to the opposing communications device and the round-trip delay time between the device itself and the opposing communications device over a certain period of time; a convergence determination means for estimating an available bandwidth, which is the communication bandwidth available to the opposing communications device, using the time series data when it is determined that the transmission rate has converged to a certain bandwidth; and a transmission rate calculation means for calculating a new transmission rate using a calculation formula having an increase term and a decrease term, wherein the decrease term has a larger value as the value obtained by subtracting the transmission rate from the available bandwidth increases, and a smaller value as the value obtained by subtracting the available bandwidth from the transmission rate decreases.

Provided is a wireless communication device capable of reducing a guard time when performing TDD communication. The wireless communication device performs time division duplex (TDD) wireless communication. The wireless communication device comprises: a means for setting the duration of a transmission / reception period, in which a transmission period for transmitting a signal to a target device and a reception period for receiving a signal from the target device in TDD wireless communication come in succession, to the same duration as a round-trip delay time of a wireless signal between the wireless communication device and the target device; and a means for periodically performing transmission to the target device and reception from the target device by repeating the transmission / reception period.

A communication device for transmitting data to a counter device via a network, said communication device comprising a processing unit that calculates an expected transmission rate expected during non-congestion on the basis of the amount of transmission data that has not been acknowledged and a value relating to a round-trip delay time, calculates an estimated reception rate on the basis of the amount of transmission data that has been acknowledged, and determines that congestion has occurred in the network if the expected transmission rate exceeds the estimated reception rate.

To provide a radio communication device capable of reducing a guard time when performing communication of a TDD system.SOLUTION: A radio communication device performs radio communication of a TDD (time division duplex) system. The wireless communication device includes means for setting a time length of a transmission and reception period in which a transmission period for transmitting a signal to a target device and a reception period for receiving a signal from the target device in wireless communication of a TDD scheme are continuous to the same time length as a round-trip delay time of a wireless signal between the wireless communication device and the target device, and means for periodically performing transmission to the target device and reception from the target device by repeating the transmission and reception period.SELECTED DRAWING: Figure 10

A method is proposed for determining a round-trip delay time (RTT) between first and second points of a communication network based on data units propagating according to a first protocol belonging to a first protocol layer, and to a second protocol belonging to a second protocol layer higher than the first protocol layer, wherein said data units comprise first and second data units that, during propagation, are at the first and second points, respectively.

A device senses an environment by transmitting radar pulses encoded with a known sequence, the radar pulses having a pulse length as long as a maximum round-trip delay time corresponding to a maximum radar distance. Thereafter, a reflection of the pulse is received, where the reflection length is shorter than the pulse length. Generating a set of correlation results representing a correlation of the received radar reflection with differently delayed replicas of the radar pulse, where each of the differently delayed replicas has a corresponding delay hypothesis selected from a set of delay hypotheses, a range of the set of delay hypotheses is between a minimum delay hypothesis associated with a minimum radar distance and a maximum delay hypothesis associated with a maximum radar distance. A copy of the delay of the radar pulse that produces a target correlation result of the set of correlation results is found, and the delay assumption is used to estimate the distance of the sensed object in the environment.

In a communication system (50), a FlexBr(Master) (1) and a FlexBr(Slave) (2) each having a bridge function between a low-speed interface and a high-speed interface are connected by an optical path, the FlexBr(Slave) (2) notifies the FlexBr(Master) (1) of information related to the FlexBr(Slave) (2) and including information relating to a data amount currently stored in an input buffer unit to which data is input from a user terminal (20), and the FlexBr(Master) (1) performs bandwidth control of the input buffer unit of the FlexBr(Slave) (2) on the basis of a round-trip delay time calculated from the transmission time of the information related to the FlexBr(Slave) (2) and the reception time of the information related to the FlexBr(Slave) (2), and the information relating to the data amount currently stored in the input buffer unit such that time division multiplex control output in the low-speed interface thereof becomes possible.