摘要:
Provided are a system and method for position awareness that can be used indoors in a large-scale environment and can minimize generation of radio frequency (RF) and ultrasonic waves in a wireless sensor network including low-priced sensor nodes capable of precise position measurement, thus improving energy efficiency by reducing unnecessary power consumption. The method includes the steps of: (a) calculating initial position coordinates using beacon information received from adjacent beacons through a broadcast beacon solicitation signal, sending a synchronization signal to the beacons, and synchronizing the beacons; (b) receiving ultrasonic waves generated from the adjacent beacons activated by a broadcast start message, and calculating position coordinates; and (c) when the calculated position coordinates correspond to a predetermined hand-off threshold position, transmitting a hand-off process message to a newly activated beacon, and executing a hand-off process routine.
摘要:
The present invention relates to a circuit for searching a fault location in a device having a number of ASIC's, including a first BIP(Bit Interleaved Parity) generating unit, which is coupled to the input stage of the ASIC where a fault will be detected, for calculating and outputting BIP for the specific byte, which is one of overhead bytes that were already utilized, i.e., not in use in transmission line, during a certain period; a BIP extraction unit, which is in parallel connected with the first BIP generating unit, for extracting the same byte as said specific byte from overhead bytes, which are generated and inserted in the previous-stage ASIC, in order to compare with BIP inputted into the first BIP generating unit during a certain period; a BIP comparison unit for simply comparing the result outputted from the first BIP generating unit with the result outputted from the BIP extraction unit; a BIP accumulation unit for accumulating the results outputted by the BIP comparison unit; a BIP threshold interrupt processing unit for comparing the results accumulated by the BIP accumulation unit with the threshold value which is used as the reference for generating an interrrupt, and then externally outputting the compared result; a second BIP generating unit, which is coupled to the output stage of the ASIC, for calculating and then outputting BIP for all the bytes within the transmission line(HBUS) during a certain period in order to inspect the signal of HBUS to the next-stage ASIC; and a BIP inserting unit for inserting the result generated from the second BIP generating unit into the specific byte location whithin said transmission line.
摘要:
A cross-connection apparatus for tributary unit-12 signal included in a synchronous transfer module-N signal used as a connection signal between synchronous digital hierarchy network nodes, is provided, including, an input/output and tributary unit time switching means for receiving a signal structured in the form of a frame (HEBUS) made up with an administration unit 3 signal, identifier byte and bit interleaved parity byte, performing an administration unit 3 pointer processing, virtual container 3 path overhead processing and tributary unit-12 pointer processing in order to be connected to the switching network, and thus performing a tributary unit-12 unit switching function; and a space switching means for receiving a frame (LBUS) made up with the tributary unit-12 signal, identifier byte and bit interleaved parity byte, namely, an LBUS signal, from the input/output and tributary unit time switching means, the means performing and outputting a space switching operation with the signal.
摘要:
A communication method of a coordinator in a bidirectional event transmission sensor network comprising a sensor node and the coordinator is provided. The method includes sensing, in an uplink section, whether a signal having energy greater than or equal to a predetermined magnitude is received, the signal indicating occurrence of an uplink event detected by the sensor node, and transmitting, to the sensor node in a downlink section, a synchronization packet that is used for receiving the uplink event or for transmitting a downlink event in response to the coordinator detecting the downlink event or sensing the signal having energy greater than or equal to the predetermined magnitude in the uplink section. The bidirectional event transmission sensor network has a structure of a super frame that includes at least one standby slot (SS) including the uplink section and the
摘要:
A communication method of a coordinator in a bidirectional event transmission sensor network comprising a sensor node and the coordinator is provided. The method includes sensing, in an uplink section, whether a signal having energy greater than or equal to a predetermined magnitude is received, the signal indicating occurrence of an uplink event detected by the sensor node, and transmitting, to the sensor node in a downlink section, a synchronization packet that is used for receiving the uplink event or for transmitting a downlink event in response to the coordinator detecting the downlink event or sensing the signal having energy greater than or equal to the predetermined magnitude in the uplink section. The bidirectional event transmission sensor network has a structure of a super frame that includes at least one standby slot (SS) including the uplink section and the downlink section.