Abstract: A method is disclosed for providing backup network services in a communications network used by mobile terminals such as cellular telephones. The method includes receiving information regarding a terrestrial base station of the communications network and, using a non-terrestrial base station (NTBS) such as an orbiting satellite, detecting an incapacity of the terrestrial base station. The NTBS identifies a second NTBS (e.g., a second satellite) within communications range to provide backup service to the communications network. The second NTBS is then introduced as a new base station of the communications network. The second NTBS can then substitute for the incapacitated terrestrial base station to carry traffic between at least one mobile terminal and the communications network.

Abstract: User equipment of a communication system in one aspect obtains data indicative of the position of a satellite, and obtains data indicative of the position of the user equipment. The user equipment computes a delay measure based on the data indicative of the position of the satellite and the data indicative of the position of the user equipment, and adjusts the timing of a communication transmitted from the user equipment to the satellite based on the delay measure. In an illustrative embodiment, the user equipment receives data indicative of position and velocity of the satellite, and adjusts both timing and frequency of the communication based on the position and velocity data. The timing and frequency adjusted communication may then be transmitted to the satellite over a unicast uplink channel.

Abstract: User equipment of a communication system in one aspect obtains data indicative of the position of a satellite, and obtains data indicative of the position of the user equipment. The user equipment computes a delay measure based on the data indicative of the position of the satellite and the data indicative of the position of the user equipment, and adjusts the timing of a communication transmitted from the user equipment to the satellite based on the delay measure. In an illustrative embodiment, the user equipment receives data indicative of position and velocity of the satellite, and adjusts both timing and frequency of the communication based on the position and velocity data. The timing and frequency adjusted communication may then be transmitted to the satellite over a unicast uplink channel.

Abstract: A method for modulating first and second bit streams in a communications network that supports at least one of a binary phase-shift keying (BPSK), a quadrature phase-shift keying (QPSK) or a quadrature amplitude modulation (QAM) constellation uses hierarchical modulation. A hierarchical modulation parameter that varies within the network is set. The first bit stream is modulated based on a first constellation of the hierarchical modulation and the hierarchical modulation parameter. The second bit stream is modulated based on a second constellation in the first constellation.

Abstract: A method and an apparatus for enabling a digital wireless service across a first and a second wireless communications environment is provided. The method comprises translating a receive signal carried on a forward link and having a first carrier frequency in the first wireless communications environment from a first frequency band to a second frequency band different from the first frequency band. The method further comprises translating a transmit signal carried on a reverse link and having a second carrier frequency in the first wireless communications environment from the second frequency band to the first frequency band. In this way, a digital wireless service may be provided between a mobile station and at least one base station on the ground across two different wireless communications environments. The method further comprises compensating Doppler shift separately for individual beams directed at a plurality of terrestrial base stations.

Abstract: In one embodiment of the method, a base station is configured to divide a coverage area of the base station into sub-coverage areas. Each sub-coverage area has a smaller range of round trip propagation delays than a range of round trip propagation delays for the coverage area of the base station. Each sub-coverage area may have a different range of round trip propagation delays.

Abstract: In one embodiment of the method, a base station is configured to divide a coverage area of the base station into sub-coverage areas. Each sub-coverage area has a smaller range of round trip propagation delays than a range of round trip propagation delays for the coverage area of the base station. Each sub-coverage area may have a different range of round trip propagation delays.

Abstract: An apparatus for providing wireless transmission of information in electronic display systems and methods of using the same. In particular, the present invention is directed to an air interface and protocol to facilitate wireless transmission of information from a communication base station or other controlling device to individual electronic display modules.

Abstract: A modulated backscatter communication system (e.g., an Electronic Shelf Label (ESL) system) includes a central node (e.g., a ceiling node) and one or more remote nodes (e.g., ESL tags). The central node transmits a downlink radio signal which is reflectively modulated at a remote node to produce a modulated reflected radio signal. At the remote node, a precise-frequency subcarrier signal is modulated with an uplink information signal to produce a modulated signal which is used to produce the modulated reflected radio signal. At the central node, the modulated reflected radio signal is received, detected and narrowband filtered to obtain the modulated subcarrier signal which is then demodulated to obtain the uplink information signal, with great immunity to close to carrier downlink radio noise and fluorescent light backscatter interference.

Abstract: A modulated backscatter communication system (e.g., an Electronic Shelf Label (ESL) system) includes a central node (e.g., a ceiling node) and one or more remote nodes (e.g., ESL tags). The central node transmits a downlink radio signal which is reflectively modulated at a remote node to produce a modulated reflected radio signal. At the remote node, a precise-frequency subcarrier signal is modulated with an uplink information signal to produce a modulated signal which is used to produce the modulated reflected radio signal. At the central node, the modulated reflected radio signal is received, detected and narrowband filtered to obtain the modulated subcarrier signal which is then demodulated to obtain the uplink information signal, with great immunity to close to carrier downlink radio noise and fluorescent light backscatter interference.

Abstract: A modulated backscatter communication system (e.g., an Electronic Shelf Label (ESL) system) includes a central node (e.g., a ceiling node) and one or more remote nodes (e.g., ESL tags). The central node transmits a downlink radio signal which is reflectively modulated at a remote node to produce a modulated reflected radio signal. At the remote node, a precise-frequency subcarrier signal is modulated with an uplink information signal to produce a modulated signal which is used to produce the modulated reflected radio signal. At the central node, the modulated reflected radio signal is received, detected and narrowband filtered to obtain the modulated subcarrier signal which is then demodulated to obtain the uplink information signal, with great immunity to close to carrier downlink radio noise and fluorescent light backscatter interference.

Abstract: An electronic shelf label has a housing which is formed oversized and later shaped to fit securely into a C channel of a targeted shelf, without requiring any additional hardware fixtures for mounting.

Abstract: A modulated backscatter communication system (e.g., an Electronic Shelf Label (ESL) system) includes a central node (e.g., a ceiling node) and one or more remote nodes (e.g., ESL tags). The central node transmits a downlink radio signal which is reflectively modulated at a remote node to produce a modulated reflected radio signal. At the remote node, a precise-frequency subcarrier signal is modulated with an uplink information signal to produce a modulated signal which is used to produce the modulated reflected radio signal. At the central node, the modulated reflected radio signal is received, detected and narrowband filtered to obtain the modulated subcarrier signal which is then demodulated to obtain the uplink information signal, with great immunity to close to carrier downlink radio noise and fluorescent light backscatter interference.

Abstract: Electronic display system capable of displaying communication signal strength on individual electronic display modules and method of using the same. In one preferred embodiment of the present invention, a pseudo-price change command is transmitted by a base communication station to an individual electronic display module and the strength of the acknowledgment signal returned by the individual electronic display module is observed and temporarily recorded. The base communication station then transmits a command to change the electronic display on that particular electronic display module to display the value of the received communication signal strength.

Abstract: An electronic label device includes a display device and a microcomputer connected to control the display device. The microcomputer includes a memory having a plurality of registers. Data received via an antenna is stored in the registers. The microcomputer is indirectly controlled to selectively display data stored in the registers on said display device. The indirect control is effected by coupling signals to the said microcomputer without physical contact with elements of the label device, such as by a magnetic reed switch, capacitor coupling or inductive coupling.