摘要:
A method, apparatus, computer-based product and system employs a digital receiver (or transceiver) to receive, digitize and process a direct sequence spread spectrum signal using efficient, low-cost digital signal processing components. A radio front end portion of the receiver receives and digitizes the signal, and a digital signal processing portion downconverts and despreads the signal by applying a pseudorandom noise (PN) code, used at a transmitter to spread a data signal contained in the direct sequence spread spectrum signal, to the received signal. In order to initially align, and maintain alignment of, the PN code with the direct sequence spread spectrum signal, a timing and state control mechanism is included that provides time reference correction information to the signal processing components of the receiver. This time reference correction information allows the receiver to be compatible with transmitters using inaccurate frequency references which impart a significant frequency ambiguity in the received signal. Additional features include computer-based synchronization methods and mechanisms suitable for use for low performance digital signal processors and employ power management mechanisms that enable long-term operation using battery power. The power management mechanisms enable the receiver to operate in a network setting, over the course of multiple years off battery power, with similar receivers, transmitters and transceiver that communicate with one another using direct sequence spread spectrum signals.
摘要:
A cellular wireless packet data communication system containing transmit-only endpoint devices which transmit to receive-only base stations. The system is configured to allow for large area coverage (e.g., a metropolitan area) with far fewer number base stations than are required with conventional two-way cellular systems. The base station coverage areas are configured to overlap, allowing for reception of packets at multiple base stations. A data concentrator resolves redundantly received messages. The network is configurable as a WAN, a LAN, or a combination of the two. Novel modulation techniques (e.g., a 16QAM submodulation together with a 7FSK modulation) are used such that low cost components can be used in the transmitters and receivers while achieving outstanding probability of success performance. The endpoint devices are battery operated and accordingly, are designed for low power consumption and multi-year battery life. The system is used in a variety of applications including remote monitoring and mobile communications.
摘要:
A cellular wireless packet data communication system containing transmit-only endpoint devices which transmit to receive-only base stations. The system is configured to allow for large area coverage (e.g., a metropolitan area) with far fewer number base stations than are required with conventional two-way cellular systems. The base station coverage areas are configured to overlap, allowing for reception of packets at multiple base stations. A data concentrator resolves redundantly received messages. The network is configurable as a WAN, a LAN, or a combination of the two. Novel modulation techniques (e.g., a 16QAM submodulation together with a 7FSK modulation) are used such that low cost components can be used in the transmitters and receivers while achieving outstanding probability of success performance. The endpoint devices are battery operated and accordingly, are designed for low power consumption and multi-year battery life. The system is used in a variety of applications including remote monitoring and mobile communications.
摘要:
A remote endpoint monitor device includes a remote endpoint device including a meter, a position locator, a frequency selector, and a communication unit. The meter is configured to measure a service parameter to provide a measured service parameter value. The position locator is configured to determine a position of the remote endpoint device. The frequency selector is configured to select a transmission frequency device based on the determined position. The transmitter is configured to transmit service information data including the service parameter value at the transmission frequency selected by the frequency selector. A method of a remote endpoint monitor device includes measuring a service parameter, determining a position of the remote endpoint device, selecting a transmission frequency of the remote end point device, and transmitting service information data at the transmission frequency. Thus, the remote endpoint monitor device is capable of handling an automatic frequency switchover without direction provided externally.
摘要:
A method, system, apparatus, and computer program product for relaying packet information from an Out of Range Device (ORD) to a communications tower. The method includes transmitting a message from the ORD. The message is recognizable by a transceiver device as a message to be repeated. The message is stored in the transceiver device which also measures a received signal quality of the message, and relays the message after delaying for a time interval inversely proportional to received signal quality.
摘要:
A system for detecting, at a remote location, a deterioration in an electrical connection, such as an electrical meter socket connection, includes at least one deterioration sensing device that includes an apparatus for detecting, at a remote location, a deterioration in an electrical connection; at least one fixed or portable receiving communication device, each configured to receive temperature information from the at least one deterioration sensing device and to transmit the temperature information via a communication network; and a back end connected to the communication network and configured to receive temperature information from the at least one fixed or portable sensing communication device. Upon exceeding a predetermined condition, the back-end may forward an alarm warning to a utility.
摘要:
A system for detecting, at a remote location, a deterioration in an electrical connection, such as an electrical meter socket connection, includes at least one deterioration sensing device that includes an apparatus for detecting, at a remote location, a deterioration in an electrical connection; at least one fixed or portable receiving communication device, each configured to receive temperature information from the at least one deterioration sensing device and to transmit the temperature information via a communication network; and a back end connected to the communication network and configured to receive temperature information from the at least one fixed or portable sensing communication device. Upon exceeding a predetermined condition, the back-end may forward an alarm warning to a utility.