摘要:
Since a transmission route is set in accordance with the number of relaying broad band switching nodes present between two terminating nodes of a plurality of broad band switching nodes, a through-put characteristic, an affecting degree due to occurrence of a defect, the traffic of the entire network is distributed. In addition, when the system is started up, transmission routes with a minimum band width necessary for routing control have been set in all the broad band switching nodes. Whenever a call takes place, a transmission route is set and the band width is variably set by using an intelligent inference mechanism. Moreover, an intelligent distributed control for distributing such an intelligent inference mechanism in the broad band switching nodes is used. Thus, the load of processing a call can be decreased, while the reliability of the network and the improvement of the operating efficiency can be achieved. Furthermore, since the private branch system interface uses a frame which consists of a control window area for controlling its transmission and a cell multiplexing area for multiplexingly transmitting cells, bidirectional transmission between the broad band switching node and a plurality of terminal equipments can be achieved with a single extension transmission line. In addition, since a frame construction which satisfies the ATM method is used, different information transmission speeds can be flexibly selected.
摘要:
In the frequency-division multiplex broadband multimedia network of this invention, a plurality of transmission paths are laid out in a matrix, with transmission path switches being arranged at respective lattice points. Each transmission path switch monitors a transmission path current. When a transmission path switch detects that a current has been cut off, a portion where a communication trouble is caused is disconnected from the network, and the switch connects a portion at the downstream side of this tansmission path switch to another adjacent transmission path.
摘要:
In a radio information communication system of this invention, at least part of a transmission data string is first divided into a plurality of bit strings when data is transmitted by radio in a radio station on the transmission side and a plurality of carrier waves of different frequencies are subjected to primary modulation by the divided bit strings. Then, the primary-modulated carrier waves are subjected to secondary modulation by the spread spectrum system such as the frequency hopping system or chirp system and modulated waves obtained by the secondary modulation are transmitted.
摘要:
A time-division multiplexing communication network comprising a central station and a plurality of local stations, in which information signals are transmitted from the local stations to the central station on a time-division multiplexing basis, and the central station transmits information signals to the local stations on a time-division multiplexing basis. The central station sequentially requests that local stations transmit a test signal in order to prevent collision of transmission signals from the local stations. Each local station, of which a test signal transmission is requested, transmits the test signal to the central station. The central station sends back the test signal to the local station which transmitted this test signal. The local station measures transmission delay time from transmission to reception of the test signal, and adjusts transmission timing of the information signal to be transmitted to the central station based on the measured delay time.
摘要:
A plurality of information processors are coupled by respective modems to a communication medium at points thereof. Transmission and reception of information signals among the modems are effected through a headed located at a predetermined point on the communication medium. A pilot signal generator is provided which sends out a pilot signal having a predetermined reference level through the headend to the communication medium. Each modem is arranged to properly adjust the gain of its transmitting amplifier according to a reception level of the pilot signal for an improvement of signal transmission quality and a reliable detection of a signal collision.
摘要:
A panel for free access to a signal cable and a power cable is installed on the floor of an office room and forms a network of signal cables in an office. The posts of this panel are mounted on the floor. A floor plate is secured to the upper ends of the posts. A rack plate is arranged between the floor plate and the floor, and the rack plate is secured to the posts. The height of the floor plate and the rack plate is adjusted by adjusting the engaging position by rotating a leg to be engaged with the threaded holes of the posts. The floor plates are composed of a plate made of glass, reinforced cement mixed with foamable styrol or an aluminum honeycomb structure. The rack plate is composed of a transparent polypropylene plate. Further, the surface of the floor plate is covered with a surface material such as a carpet. The signal cables are arranged in the space between the floor plates and the rack plates. The power cables are arranged in the space between the rack plates and the floor. Electronic components are mounted on the rack plates. Therefore, the power cables, the signal cables and the other electronic components are completely isolated from each other, and the modification of the layout of office automation equipment can be readily carried out by an authorized person.
摘要:
In a communication network in which a plurality of information processors are coupled to a communication medium through medium attachment units (MAUs), a pilot signal generator sends a pilot signal of a reference level to a predetermined point of the communication medium. Each MAU has a gain controller to control the gains of transmission and reception amplifiers. This gain controller adjusts the gain of the reception amplifier when the pilot signal is received in accordance with the reception level thereof and then allows a test signal to be transmitted to the communication medium through the transmission amplifier. The gain of the transmission amplifier is adjusted in accordance with the reception level of this test signal such that the reception level of the test signal becomes equal to the reception level of the pilot signal. Each MAU is provided with a random number data generator and sets the transmission time slot of the test signal in dependence on random number data to prevent simultaneous transmission of test signals from MAUs.
摘要:
An information transmission system in which a plurality of data terminal equipments (DTEs) are coupled with a communication medium through corresponding medium attachment units (MAUs). The DTE transmits and receives an information signal in a format having a preamble section including a predetermined bit pattern and a data section. The MAU modulates and demodulates the information signal. The MAU is arranged to replace part of the preamble with random data in order to quickly detect the collision of information signals from a plurality of DTEs on the communication medium.
摘要:
A local network, in which a plurality of data processors are coupled by modems to a communication medium, is disclosed. Each modem is arranged to shift a carrier frequency to a first and second frequency according to a digital signal from the associated data processor. In order to provide for reliable and quick detection of a collision of signals simultaneously transmitted from a plurality of modems to the communication medium, the difference between the first and second frequencies is set such that one cycle of a beat signal generated on the communication medium due to a collision of signals is not longer than one bit time length of the digital signal.
摘要:
A panel for free access to a signal cable and a power cable is installed on the floor of an office room and forms a network of signal cables in an office. The posts of this panel are mounted on the floor. A floor plate is secured to the upper ends of the posts. A rack plate is arranged between the floor plate and the floor, and the rack plate is secured to the posts. The height of the floor plate and the rack plate is adjusted by adjusting the engaging position by rotating a leg to be engaged with the threaded holes of the posts. The floor plates are composed of a plate made of glass, reinforced cement mixed with foamable styrol or an aluminum honeycomb structure. The rack plate is composed of a transparent polypropylene plate. Further, the surface of the floor plate is covered with a surface material such as a carpet. The signal cables are arranged in the space between the floor plates and the rack plates. The power cables are arranged in the space between the rack plates and the floor. Electronic components are mounted on the rack plates. Therefore, the power cables, the signal cables and the other electronic components are completely isolated from each other, and the modification of the layout of office automation equipment can be readily carried out by an authorized person.