Abstract: A processing unit generates timing information on timing, with which each of radio apparatuses is to synchronize in communication between the radio apparatuses when each of the radio apparatus broadcasts a signal, to control the communication between the radio apparatuses. A modem unit and the like broadcast the thus generated timing information. An RF unit and the like receive a signal which is synchronous with the timing information broadcast by them. When a signal which is asynchronous with the timing information and when the duration of this signal continues for a period longer than a first threshold value and the quality of this signal is more deteriorated than a second threshold value, a decision unit detects that the received signal is a disturbing signal. The modem unit and the like also broadcast to the effect that the disturbing signal has been detected.

Abstract: An RF unit receives periodically signals broadcast by other terminal apparatuses. When the quality of the signal received periodically is more deteriorated than a second threshold value even though the intensity of the signal received periodically is larger than a first threshold value, an identifying unit detects a malfunction in another terminal apparatus from which the signal received periodically by the receiver has been broadcast. A processing unit, a modem unit, the RF unit and an antenna each broadcasts a signal containing the detection result that the malfunction has been detected and information on a detected location.

Abstract: A control information extraction unit receives information on a frame that contains at least a plurality slots from an access control apparatus for controlling communications between radio apparatuses. The control information extraction unit generates a frame that contains at least a plurality of slots in such a manner as to synchronize with the frame corresponding to the received information. An estimation unit (82) estimates empty slots in the plurality of slots generated. A selection unit selects, at random, at least one of the estimated. A modem unit and the like broadcast data using the selected slot.

Abstract: A frame specifying unit frames in such a manner that a frame containing at least a plurality of slots is repeated and in such a manner that a part of the plurality of slots contained in each frame are reserved for use on an access control apparatus. An empty slot identifying unit detects a slot, which is usable for the communications between radio apparatuses, from among the remaining part of the plurality of slots. A selection unit selects a slot from among the part of the plurality of slots in order to broadcast information on the detected slot. A modulation unit and an RF unit broadcast information on the slot detected by the empty slot identifying unit, using the selected slot.

Abstract: A data processing unit selects either one of a base station mode and a terminal mode so as to perform communications using packet signals. The base station mode is a mode in which a packet signal, containing data indicating that an initial source and a final destination are not its own radio apparatus, is to be communicated; the terminal mode is a mode in which a packet signal, containing data indicating that the initial source or the final destination is its own radio apparatus, is to be communicated. A control unit starts the radio apparatus by setting the data processing unit in the terminal mode. When a packet signal, which has been transmitted from another radio apparatus and which contains broadcast information, has not been received before a certain period of time elapses after the start, the control unit switches the mode of the data processing unit to the base station mode.

Abstract: It is specified in a manner such that a frame containing a first period formed by a plurality of slots and a second period having a predetermined length is repeated. A detecting unit detects a slot, which is usable for the communications between a plurality of other terminal apparatuses, from among a plurality of slots in the first period of a frame containing the first period and the second period. A modem unit and an RF unit broadcast information on the detected slot.

Abstract: It is specified that a frame containing at least the plurality of slots is repeated. A detecting unit detects a slot usable in the communications between terminal apparatuses, from among a plurality of slots. A modem unit and an RF unit broadcast the information on the detected slot. A power measuring unit in the detecting unit measures the respective received powers of the plurality of slots, and an empty slot identifying unit identifies a slot whose received power is less than a threshold value.

Abstract: A packet communication unit and a signal processing unit communicate with a plurality of terminals, respectively, in an infrastructure mode. A control unit controls the communications performed by the packet communication unit and the signal processing unit. The control unit permits two of the plurality of terminal apparatuses to communicate with each other in an ad-hoc mode, over a predetermined period time, and specifies the ad-hoc period to at least the two terminal apparatuses via the packet communication unit and the signal processing unit.

Abstract: A wireless unit performs a frequency conversion process, a quadrature modulation process, and a quadrature detection process. A modem performs a modulation/demodulation process. A processing unit performs digital signal processing on a signal from the modem and on a signal to the modem. An image capturing unit acquires an external image and outputs the acquired image to a coding unit. The coding unit generates image data by performing a compression encoding process on the image received from the image capturing unit and outputs the image data to a control unit. The control unit controls the overall movement of a vehicle camera apparatus.

Abstract: A packet receiver receives an instruction, sent from other radio apparatuses, as to the transfer mode used when data signals received from the other radio apparatuses are to be forwarded. A setting unit sets the transfer mode based on the instruction received. The setting unit sets a primary transfer mode or a secondary transfer mode as the transfer mode. The probability of carrying out a transfer by a packet generator and a packet transmitter under the primary transfer mode is defined to be higher than that under the secondary transfer mode. The packet generator and the packet transmitter transfer the data signals received from the other radio apparatuses, according to the transfer modes respectively set.

Abstract: A packet communication unit (20) executes radio communications in such a manner as to be accessible to other terminal apparatuses that have already been communicating wirelessly with a base station apparatus. The signal processing unit (22) generates a connection request signal to be transmitted from the packet communication unit (20) to the base station apparatus by way of the other terminal apparatuses. The signal processing unit (22) processes a connection response signal received, from the base station apparatus, by the packet communication unit 20. Such a sequence of operations allows the signal processing unit (22) to perform connection processing between a terminal apparatus and the base station apparatus.

Abstract: When a control unit receives an authentication request from a terminal apparatus, the control unit transmits an authentication response to the terminal apparatus. When it receives a connection request from the terminal apparatus to which the authentication response has been transmitted, the control unit transmits a connection response to the terminal apparatus. The control unit carries out data communication with the terminal apparatus to which the connection response has been transmitted. When it receives a notification indicating that a connection has already been granted by another base station apparatus, in substitution for the authentication request, the control unit carries out data communication with the terminal apparatus.

Abstract: A running time estimation system according to the present invention is provided with a receiver for receiving running data including a plurality of time and position data having a predetermined time and a vehicle position of different vehicles at the predetermined time by use of a wireless communication system, a running data processor for generating running time estimation data in which the received running data is associated with road information from which a position and a length of a road can be determined, and a running time estimation unit for calculating a running time between designated positions by using the generated running time estimation data.

Abstract: A data rate is to be determined depending on circumstances. A control unit (30) transmits, at a predetermined frequency, a request signal by which to supply information on a data rate to a targeted radio apparatus compatible with a variable data rate. The control unit (30) receives rate information from the targeted radio apparatus. The control unit (30) sets a data rate used in the case of transmitting data, based on the information on a data rate contained in the rate information. The control unit (30) identifies the reliability level of the data rate contained in the rate information. And when the reliability level is low, the control unit (30) lowers the frequency at which the rate request signal is transmitted.

Abstract: A running time estimation system according to the present invention is provided with a receiver for receiving running data including a plurality of time and position data having a predetermined time and a vehicle position of different vehicles at the predetermined time by use of a wireless communication system, a running data processor for generating running time estimation data in which the received running data is associated with road information from which a position and a length of a road can be determined, and a running time estimation unit for calculating a running time between designated positions by using the generated running time estimation data.

Abstract: A terminal for uploading a program to a network node is provided. A request message generation unit generates a node information request message and the message is sent to a plurality of nodes on a communication path. Node information response messages are received from the plurality of the nodes and stored in a node information storage. An active node decision unit decides active nodes according to the node information response messages from the nodes and stores a list of the active nodes in an active node list storage. A program upload unit refers to the active node list and performs a process for uploading a predefined program stored in a program storage to each active node.