Abstract: A non-transitory computer-readable recording medium storing a transmission program causing a computer of a first transmission apparatus to execute a procedure, the procedure includes detecting a collision between a transmission timing of an intra-coded video frame in first video data transmitted from the first transmission apparatus and a transmission timing of an intra-coded video frame in second video data transmitted from a second transmission apparatus, changing, when the collision is detected at a first time, a frame type of the first video data to one of a forward predictive coded video frame and a bi-directional predictive coded video frame, and transmitting the first video data of which the frame type is changed, at a second time at which the intra-coded video frame in the first video data is scheduled to be transmitted.

Abstract: An information processing apparatus includes a memory, circuitry coupled to the memory, the circuitry configured to determine whether or not a binary search method is used by using a predetermined reference to determine the number of wireless access points, and search for a minimum number of access points satisfying communication requirements in a binary search loop in a case where it is determined that the binary search method is used and search for the minimum number of access points satisfying the communication requirements by decreasing the number of access points by a predetermined number of units at a time in a case where it is not determined that the binary search method is used to search for an arrangement of the wireless access points with respect to the searched minimum number of access points.

Abstract: An information processing apparatus includes a memory, circuitry coupled to the memory, the circuitry configured to determine whether or not a binary search method is used by using a predetermined reference to determine the number of wireless access points, and search for a minimum number of access points satisfying communication requirements in a binary search loop in a case where it is determined that the binary search method is used and search for the minimum number of access points satisfying the communication requirements by decreasing the number of access points by a predetermined number of units at a time in a case where it is not determined that the binary search method is used to search for an arrangement of the wireless access points with respect to the searched minimum number of access points.

Abstract: There is provided a radio wave interference analysis apparatus configured to analyze a state of interference due to a plurality of interference signals of a plurality of interference sources on a target signal of a wireless device as an evaluation target at a reception point, the radio wave interference analysis apparatus including a memory, and a processor coupled to the memory and the processor configured to calculate a first probability of failure of reception of the target signal at the reception point due to collision of the target signal with an interference signal of the plurality of interference signals, calculate a second probability of failure of reception of the target signal at the reception point due to the interference signal of the plurality of interference sources, and output the first probability and the second probability.

Abstract: A base station apparatus includes a processor, a memory and a communication circuit. The processor is configured to set a waiting period in which a packet from a terminal device to which a connection has not been established is awaited. The memory is configured to store data that is processed by a terminal device to which a connection is established. The communication circuit is configured to, upon receiving a first packet from a communication terminal device in the waiting period, transmit to the communication terminal device a second packet containing the data and information used by the communication terminal device for establishing a connection.

Abstract: A non-transitory computer-readable recording medium storing a program that causes a computer to execute a procedure to determine a feature of each standard of a wireless environment in which radio signals including a CSS signal chirp-modulated co-exist, the procedure includes obtaining a spectrum by subjecting each radio signal to fast Fourier transform with predetermined frequency resolution and time resolution capable of visualizing a feature of the CSS signal, coarsening the frequency resolution of the spectrum by adopting an effective value in a specific frequency domain, calculating a duration of the radio signal, based on the coarsened frequency resolution of the spectrum, coarsening the time resolution of the spectrum by adopting an effective value in the duration, calculating a bandwidth of the radio signal, based on the coarsened time resolution of the spectrum, and determining the feature of the radio signal of each standard, based on the duration and the bandwidth.

Abstract: A non-transitory computer-readable recording medium storing a program that causes a computer to execute a procedure to determine a feature of each standard of a wireless environment in which radio signals including a CSS signal chirp-modulated co-exist, the procedure includes obtaining a spectrum by subjecting each radio signal to fast Fourier transform with predetermined frequency resolution and time resolution capable of visualizing a feature of the CSS signal, coarsening the frequency resolution of the spectrum by adopting an effective value in a specific frequency domain, calculating a duration of the radio signal, based on the coarsened frequency resolution of the spectrum, coarsening the time resolution of the spectrum by adopting an effective value in the duration, calculating a bandwidth of the radio signal, based on the coarsened time resolution of the spectrum, and determining the feature of the radio signal of each standard, based on the duration and the bandwidth.

Abstract: A radio analyzer includes a memory configured to store a first reference signal, and a processor coupled to the memory and configured to calculate a first correlation value between a received wave and a non-modulated wave, calculate a second correlation value between the received wave and the first reference signal in a target section of the received wave, the first correlation value being smaller than a first threshold value in the target section, and detect a modulated wave from the received wave based on the second correlation value.

Abstract: There is provided a radio wave interference analysis apparatus configured to analyze a state of interference due to a plurality of interference signals of a plurality of interference sources on a target signal of a wireless device as an evaluation target at a reception point, the radio wave interference analysis apparatus including a memory, and a processor coupled to the memory and the processor configured to calculate a first probability of failure of reception of the target signal at the reception point due to collision of the target signal with an interference signal of the plurality of interference signals, calculate a second probability of failure of reception of the target signal at the reception point due to the interference signal of the plurality of interference sources, and output the first probability and the second probability.

Abstract: There is provided a wireless analysis apparatus including: a memory unit configured to store information of electric power distribution indicating a temporal change of a frequency spectrum; and a computing unit configured to perform a procedure including: generating a plurality of divided regions having predetermined band widths by dividing the electric power distribution, calculating a temporal change amount of electric power with regard to each of the divided regions, detecting a rising portion and a falling portion of the electric power on the basis of the calculated temporal change amount, and identifying an individual signal component in the electric power distribution on the basis of the positions of the rising portion and the falling portion in the divided regions.

Abstract: A base station apparatus that communicates with a radio communication terminal in a radio communication system, includes: processor configured to detect interference between the radio communication system and another radio communication system, and determine whether or not to switch a radio channel used to communicate with the radio communication terminal when the interference is detected; and a channel switching unit that switches the radio channel when the processor determines to switch the radio channel, and does not switch the radio channel when the processor determines not to switch the radio channel.

Abstract: An apparatus for assigning time slots refers to a hierarchical structure when a predetermined number of time slots in one of a plurality of communication cycles is assigned to a communication apparatus, identifies an associated frame whose use status is to be changed to used by the assignment of the predetermined number of time slots for a group managed in a layer corresponding to the requested communication cycle, and makes determination to assign a frame belonging to a group in which a number of time slots, in the associated frame, whose use status is changed to used is smaller, to the communication apparatus.

Abstract: A radio analyzer includes a memory configured to store a first reference signal, and a processor coupled to the memory and configured to calculate a first correlation value between a received wave and a non-modulated wave, calculate a second correlation value between the received wave and the first reference signal in a target section of the received wave, the first correlation value being smaller than a first threshold value in the target section, and detect a modulated wave from the received wave based on the second correlation value.

Abstract: A radio analysis apparatus includes: a processor that calculates a modulation index of a radio signal generated by performing frequency shift keying on a baseband signal, based on phase shift amounts of the radio signal; and a memory that holds information in which bit patterns of the baseband signal are associated with correction values for correcting the phase shift amounts that have dropped by band limitation on the baseband signal. The processor restores the bit patterns of the baseband signal based on the phase shift amounts of the radio signal, corrects the phase shift amounts of the radio signal by using the correction values corresponding to the restored bit patterns, and calculates the modulation index based on the corrected phase shift amounts.

Abstract: There is provided a wireless analysis apparatus including: a memory unit configured to store information of electric power distribution indicating a temporal change of a frequency spectrum; and a computing unit configured to perform a procedure including: generating a plurality of divided regions having predetermined band widths by dividing the electric power distribution, calculating a temporal change amount of electric power with regard to each of the divided regions, detecting a rising portion and a falling portion of the electric power on the basis of the calculated temporal change amount, and identifying an individual signal component in the electric power distribution on the basis of the positions of the rising portion and the falling portion in the divided regions.

Abstract: A radio analysis apparatus includes: a processor that calculates a modulation index of a radio signal generated by performing frequency shift keying on a baseband signal, based on phase shift amounts of the radio signal; and a memory that holds information in which bit patterns of the baseband signal are associated with correction values for correcting the phase shift amounts that have dropped by band limitation on the baseband signal. The processor restores the bit patterns of the baseband signal based on the phase shift amounts of the radio signal, corrects the phase shift amounts of the radio signal by using the correction values corresponding to the restored bit patterns, and calculates the modulation index based on the corrected phase shift amounts.

Abstract: A wireless communication system includes a transmission device, a relay device, and a reception device and is configured to execute direct communication of directly transmitting a wireless signal from the transmission device to the reception device without routing through the relay device and indirect communication of indirectly transmitting a wireless signal from the transmission device to the reception device through the relay device. The wireless communication system includes a controller configured to estimate a disconnection continuation time that is a time during which the direct communication is not executable in a case where the direct communication is not executable while the direct communication is repeatedly executed, continue to execute the direct communication when the disconnection continuation time is shorter than a threshold time, and execute the indirect communication when the disconnection continuation time is longer than the threshold time.

Abstract: An apparatus for assigning time slots refers to a hierarchical structure when a predetermined number of time slots in one of a plurality of communication cycles is assigned to a communication apparatus, identifies an associated frame whose use status is to be changed to used by the assignment of the predetermined number of time slots for a group managed in a layer corresponding to the requested communication cycle, and makes determination to assign a frame belonging to a group in which a number of time slots, in the associated frame, whose use status is changed to used is smaller, to the communication apparatus.

Abstract: A communication method for use in a communication system having a plurality of communication devices includes: a first communication device transmitting within a predefined period a connection request signal requesting a connection with another communication device; a second communication device transmitting a connection permit signal which contains the number of connection request signals received during the predefined period as the number of requesting candidates; the first communication device obtaining a transmission probability defining the probability of signal transmission such that the transmission probability decreases as the number of requesting candidates contained in the connection permit signal received from the second communication device increases; and the first communication device making a decision as to whether or not to transmit a signal out in accordance with the transmission probability at the timing that the signal can be transmitted to the second communication device.

Abstract: A base station apparatus includes a processor, a memory and a communication circuit. The processor is configured to set a waiting period in which a packet from a terminal device to which a connection has not been established is awaited. The memory is configured to store data that is processed by a terminal device to which a connection is established. The communication circuit is configured to, upon receiving a first packet from a communication terminal device in the waiting period, transmit to the communication terminal device a second packet containing the data and information used by the communication terminal device for establishing a connection.