摘要:
In a semiconductor light-emitting device including a substrate, a first compound semiconductor layer including an active layer formed on the substrate, a second compound semiconductor layer of a ridge type formed on the first compound semiconductor layer, and a protective film formed above the first compound semiconductor layer on both sides of the second compound semiconductor layer, the disclosed semiconductor light-emitting device has a current blocking layer formed above the first compound semiconductor layer outside the protective film. This semiconductor light-emitting device is with a high production yield since readily cleaved and assembled, with adequately squeezed currents, and with, when assembled in the junction-down type, a high output and a longer life span.
摘要:
A method for measuring a radio wave propagation environment includes installing radio signal transmission and reception apparatuses where a radio network system is to be constructed and obtaining an electromagnetic wave measured value of a signal between transmission and reception apparatuses; estimating an electromagnetic wave propagation state of the signal using an electrical property and information on a three-dimensional structure at the site to obtain an electromagnetic wave estimated value; making a comparison between measured and estimated values for each time of day to determine when errors between measured and estimated values exceed a reference value; obtaining an electromagnetic path between transmission and reception apparatuses; and modifying structure information in the wave path to re-obtain the estimated value; and comparing the measured re-obtained estimated value to modify the three-dimensional structure information so that the error value becomes smaller.
摘要:
A method for measuring a radio wave propagation environment includes installing radio signal transmission and reception apparatuses where a radio network system is to be constructed and obtaining an electromagnetic wave measured value of a signal between transmission and reception apparatuses; estimating an electromagnetic wave propagation state of the signal using an electrical property and information on a three-dimensional structure at the site to obtain an electromagnetic wave estimated value; making a comparison between measured and estimated values for each time of day to determine when errors between measured and estimated values exceed a reference value; obtaining an electromagnetic path between transmission and reception apparatuses; and modifying structure information in the wave path to re-obtain the estimated value; and comparing the measured re-obtained estimated value to modify the three-dimensional structure information so that the error value becomes smaller.
摘要:
A communication device reduces a processing time required at the time of mutually converting different wireless or wired communication protocol and improves a real-time property. The communication device includes two or more communication units which communicate with two or more external devices and a communication controller which processes communication data. The communication controller has table information that associates a communication path, a type of the communication unit, and conversion-info, and an input and output unit that inputs and outputs the table information. According to the added conversion-info, a conversion unit sequentially performs various conversion processes (protocol conversion, routing, communication quality evaluation, fragmentation/integration of communication interface, fragment/defragment process, frame multiplication/integration, and frequency setting).
摘要:
A multistage relay communication system 100 includes a trunk network 1 and branch networks 2 (2a, 2b), each of which includes one or more communication apparatuses 4. The communication apparatus 4 can switch between a trunk mode to operate in the trunk network 1 and a branch mode to operate in the branch network 2. In the trunk network 1, the communication apparatus 4 carries out fixing of a communication path and redundancy of data based on a path table in order to achieve real-timeness and a data arrival rate. Meanwhile, in the branch network 2, when a communication failure occurs, the communication apparatus 4 autonomously searches for a communication path and constructs a path table, in order to at least secure a data arrival rate even if real-timeness is impaired within an allowable range.
摘要:
A communication device reduces a processing time required at the time of mutually converting different wireless or wired communication protocol and improves a real-time property. The communication device includes two or more communication units which communicate with two or more external devices and a communication controller which processes communication data. The communication controller has table information that associates a communication path, a type of the communication unit, and conversion-info, and an input and output unit that inputs and outputs the table information. According to the added conversion-info, a conversion unit sequentially performs various conversion processes (protocol conversion, routing, communication quality evaluation, fragmentation/integration of communication interface, fragment/defragment process, frame multiplication/integration, and frequency setting).
摘要:
In a semiconductor light-emitting device including a substrate, a first compound semiconductor layer including an active layer formed on the substrate, a second compound semiconductor layer of a ridge type formed on the first compound semiconductor layer, and a protective film formed above the first compound semiconductor layer on both sides of the second compound semiconductor layer, the disclosed semiconductor light-emitting device has a current blocking layer formed above the first compound semiconductor layer outside the protective film. This semiconductor light-emitting device is with a high production yield since readily cleaved and assembled, with adequately squeezed currents, and with, when assembled in the junction-down type, a high output and a longer life span.
摘要:
An information exchange system is capable of realizing useful information exchange both for the service provider located along the road and providing services and the vehicular driver, by effectively using limited communication capacity of the road-vehicle radio communication. The information exchange system has a vehicle-mounted unit and a road-side unit providing information to the vehicle-mounted unit using a road-vehicle radio communication. The vehicle-mounted unit includes receiving unit receiving information transmitted from the road-side unit through a radio communication and transferring unit transferring at least a part of a content of the received information to a vehicular occupant. The road-side unit including storage unit storing information to be transmitted to the vehicle-mounted unit and transmitting unit transmitting information to the vehicle-mounted unit through the radio communication. The storage means stores at least information relating to a service provider where a service is provided at the location thereof. The road-side unit also includes editing unit editing information stored in the storage means on the basis of a relative position between the service provider and a communication region of the transmitting means and generating an edited information to be transmitted from the transmitting means.
摘要:
An information exchange system is capable of realizing useful information exchange both for the service provider located along the road and providing services and the vehicular driver, by effectively using limited communication capacity of the road-vehicle radio communication. The information exchange system has a vehicle-mounted unit and a road-side unit providing information to the vehicle-mounted unit using a road-vehicle radio communication. The vehicle-mounted unit includes receiving unit receiving information transmitted from the road-side unit through a radio communication and transferring unit transferring at least a part of a content of the received information to a vehicular occupant. The road-side unit including storage unit storing information to be transmitted to the vehicle-mounted unit and transmitting unit transmitting information to the vehicle-mounted unit through the radio communication. The storage means stores at least information relating to a service provider where a service is provided at the location thereof. The road-side unit also includes editing unit editing information stored in the storage means on the basis of a relative position between the service provider and a communication region of the transmitting means and generating an edited information to be transmitted from the transmitting means.
摘要:
In the construction of a wireless network in a building, structure conditions such as the floor plan of the building and the shape of the floor, material conditions such as materials for structures, and the like have a great effect on radio wave propagation characteristics. This causes a problem that unless these pieces of information are taken into consideration, an accurate layout design of wireless base stations cannot be made. In the construction of a new wireless network in a building, a wireless network similar to structure conditions of a newly constructed building is extracted from structure conditions of past buildings in which a wireless network is constructed. The layout positions of wireless base stations used in the extracted wireless network are regarded as the layout positions of wireless base stations in the new wireless network.