摘要:
A digital mobile communication system wherein a master clock of a mobile communication system for offering audio or data service using a code division multiple access (CDMA) is set as a global positioning system (GPS) clock provided in a GPS and the interface and timing between various subsystems using the GPS clock and an exchanger are redesigned to achieve an exact timing schedule, and a timing design method between various subsystems. In order to maintain frequency and time synchronization between various subsystems in a CDMA system using an exchanger therefor, the respective subsystems are designed based on the clock supplied from a GPS, a hardware interconnection between the systems is designed based on the GPS clock to attain an exact timing, thereby achieving a fast and exact frame transmission.
摘要:
A base station equipment, mobile station and data transmission method in a digital CDMA cellular radio network, in which base stations communicate with mobile stations located in an area. Each mobile station can have a duplex connection with more than one of the base stations simultaneously. Signals transmitted from more than one of the base stations can be combined in a respective mobile station. A signal received from a mobile station in more than one of the base stations can be combined in a base station controller. In the network, traffic channel transmission is carried out by using a predetermined frame structure. Cellular network frames of different types are transmitted between respective ones of the base stations and the mobile stations over radio paths. To simplify the structure of the base station equipment, the type of frame being transmitted is indicated by a predetermined frame identifier. If the frame identifiers of the frames received simultaneously via several paths are similar, the frames are combined, but if the frame identifiers are different, the frames are not combined.
摘要:
At least one base station is connected to at least one central office via a T1/E1 trunk. Some channels of the trunk are assigned to carry PCM data destined for the public switched telephony network via the central office, while other channels of the truck are assigned to carry packet data destined for the internet via the central office. The base station includes a wireless subscriber interface, a PCM interface, a packet data interface and a selector circuit which selectively couples an input/output of the subscriber interface to either one of an input/output of the PCM interface or an input/output of the packet data interface.
摘要:
A channel management process (68) is performed by a parent base station (36) of a radio telecommunications system (20) that exchanges channel usage data with neighbor base stations (38) within its local group (34). When channel usage data indicates a channel assignment conflict, that conflict is resolved in the base station (22) having the lesser loading of the pair of conflicting base stations (22). Channel usage requests received by a base station (22) are prioritized and sequentially processed, channels (58) being assigned for inter-cell handoff requests, then intra-cell handoff requests after inter-cell handoff requests, even when that assignment creates a conflict, and then channels (58) being assigned to new call requests after handoff requests if that assignment does not create a conflict.
摘要:
A multichannel radiotelephony system provides two way cordless communications with a plurality of multichannel transceivers portable within a coverage area comprised by a plurality of cells, each associated with a base station and antennas, such as to permit channel frequency reuse in cells within the coverage area. For at least part of the coverage area, the locations of the antennas within the cells and the locations of the base stations are independently mapped, the antennas being associated with active antenna systems and the active antenna systems being connected to the base stations utilizing broadband transmission by means of a fixed bi-directional signal distribution network. The network is connected to the base stations and the antenna systems through suitable interfaces incorporating frequency translation so that available frequency bands in the signal distribution network which will normally be shared with other services, may be utilised. Plural base stations may be co-located. The radio link to the transceivers may be frequency or time division multiplexed, but communication over the network will normally be frequency multiplexed, using separate bands for transmission and reception.
摘要:
A cellular telephone concentrated subscriber system is described. The concentrated subscriber system includes a set of subscriber units coupled to a concentrated subscriber system controller. The concentrated subscriber system controller that provides a radio frequency (RF) interface to the standard base station transceiver of a cellular telephone system. Each subscriber unit has a unique electronic serial number. The concentrated subscriber system controller includes a set of modulator-demodulator systems (modems) and a RF transceiver and antenna system that is configured to transmit sufficient information to conduct multiple telephone calls over both long and short distances. The concentrated subscriber system controller also includes control circuitry for coupling the set of subscriber unit to the set of modems via a multiplexed system using stored information. In the preferred embodiment the number of modems is significantly less the number of subscriber units which are implemented in a simplified manner so that the per user cost of cellular telephone service is reduced.
摘要:
A speech message recording and reproducing method and apparatus wherein a speech message associated with a facsimile transmission is stored in a communication apparatus having an automatic answering telephone apparatus associated with a facsimile apparatus. Information of the speech apparatus including at least a storage address thereof is converted to an optical pattern for printing on a recording paper. The printed optical pattern is optically detected, interpreted and transmitted by radio communication to the communication apparatus and the speech message stored at the storage address is reproduced. The optical pattern is read by a reader forming part of a portable telephone unit.
摘要:
An intra-premises communication system enables the use of a preinstalled wired transmission channels, yet allowing a particular communication system to be located at a desired region in the premises. The system comprises an exchange box adapted to be installed in the premises and provided with different interfaces for connection to different networks. A plurality of the wired transmission channels extend from the exchange box and terminate to receptacles which are installed in the premises and have common connectors. A plurality of indoor wireless terminals of different types are provided for use within the premises. A plurality of local transmitter-receivers of different types are provided in correspondence to the types of the wireless terminals. Each of the local transmitter-receivers is detachably and selectively mounted to the common connector of the receptacle for wired communication with one of the networks through the associated transmission channel. The local transmitter-receivers have individual antennas or the like member for wireless communication with at least one of the terminals. The exchange box includes a switch for connecting the transmission channels selectively to particular ones of the interfaces, thereby allocating local transmitter-receivers and the associated terminals to the different networks. The receptacles can be preinstalled in the like fashion as the conventional electrical receptacles so that a desired wireless communication system can be located at a suitable region simply by mounting the local transmitter-receiver of the selected type to the common connector of the receptacle.
摘要:
A system and method are shown for selecting an outbound subsystem and an inbound subsystem to be used to communicate between a subscriber unit (10) and an integrated communication system having a number of subsystems (30, 50) that are capable of operating independently. The subscriber unit (10) stores in a memory (77) for each of the different types of messages that the subscriber unit (10) can handle, a list of the subsystems that can be used to communicate the message type wherein each list is ordered according to the subscriber unit's preference for using a subsystem for outbound messages of the particular type. When the subscriber unit receives control information from the integrated system identifying a particular type of message that the system expects to communicate to the subscriber unit, the subscriber unit identifies at least one outbound subsystem in the list stored for the received message type covering the area in which the subscriber unit is located. The subscriber unit then communicates this information to the integrated subsystem using an inbound channel of the most preferred identified subsystem having one. If none of the identified subsystems includes an inbound channel the subscriber unit identifies the most preferred inbound subsystem that the subscriber unit can access regardless of message type.
摘要:
A split frequency band signal digitizer (10) includes a first mixer (18) for translating a split-band signal (200) about a multiple of the sampling frequency. The split-band signal so translated is then communicated to an analog-to-digital converter (26). The digitized signal is then analyzed to recover an original portion of the split-band signal and a second portion of the signal aliased into a single Nyquist band.