Methods and systems capable of launching signal-carrying transverse electromagnetic waves onto a transmission line in the higher voltage region of the transmission distribution network. Such methods and systems may include a surface wave launcher located in the higher voltage region, a network unit located in a lower voltage region, and an arrester separating the surface wave launcher and the network unit, the arrester preventing voltage from arcing over from the higher voltage region to the lower voltage region where the arrester provides the signal to the surface wave launcher.

It is detected of an interference of a reverse link communication in a feeder link of a communication relay apparatus, which tends to occur when the number of movable aerial-floating type communication relay apparatuses increases in the same area. A communication system comprises a plurality of movable aerial-floating type communication relay apparatuses that respectively include a relay communication station of performing a service-link radio communication with a terminal apparatus, plural gateway stations that respectively perform a feeder-link radio communication with the plurality of the communication relay apparatuses, and a common baseband processing apparatus connected to the plural gateway stations. The baseband processing apparatus detects an interference of the reverse link communication due to an interference wave from a relay communication station of another communication relay apparatus, the interference wave interfering with a signal wave from the relay communication station of the communication relay apparatus connected to the gateway station, based on plural reception signals received by the plural gateway stations.

A wireless radio frequency conversion system is disclosed. The wireless radio frequency conversion system includes a primary distributing device, a one-to-many conversion device, a plurality of first optical fiber networks, a plurality of remote antenna devices, and a plurality of antennas. The primary distributing device is configured to receive a first photoelectric signal. The one-to-many conversion device is configured to perform an optical-electrical conversion and a one-to-many conversion to the first photoelectric signal so as to generate a plurality of second photoelectric signals. The plurality of first optical fiber networks are configured to transmit the plurality of second photoelectric signals. The plurality of remote antenna devices are configured to receive and perform an optical-electrical conversion to the plurality of second photoelectric signals so as to generate a plurality of third photoelectric signals. The plurality of antennas are configured to transmit the plurality of third photoelectric signals.

Distributed antenna systems provide location information for client devices communicating with remote antenna units. The location information can be used to determine the location of the client devices relative to the remote antenna unit(s) with which the client devices are communicating. A location processing unit (LPU) includes a control system configured to receive uplink radio frequency (RF) signals communicated by client devices and determines the signal strengths of the uplink RF signals. The control system also determines which antenna unit is receiving uplink RF signals from the device having the greatest signal strength.

The present disclosure aims to make it possible to simultaneously establish communication between many freely-selected radio terminals without using a complex relay network or a plurality of radio relays. The present disclosure is a communication network system including: a plurality of optical-radio converters 521-1 to 521-n that convert a radio signal and an optical fiber radio signal into each other; and a path controller that is connected to the plurality of optical-radio converters 521-1 to 521-n through optical fiber transmission lines 531-1 to 531-n, receives input of an optical fiber radio signal transmitted from any optical-radio converter of the plurality of optical-radio converters 521-1 to 521-n from the optical fiber transmission line connected to the optical-radio converter, and outputs the optical fiber radio signal to the optical fiber transmission line connected to a set optical-radio converter of the plurality of optical-radio converters 521-1 to 521-n.

A vehicle communication system includes an optical cable, a centralized hub device, and an antenna hub device. The centralized hub device is connected to a first end of the optical cable and is configured to receive radio frequency (RF) signals from multiple end devices. The centralized hub device is configured to convert the RF signals to respective optical carrier signals and transmit the optical carrier signals along the optical cable at different, non-overlapping wavelength bands of a combined optical signal. The antenna hub device is connected to a second end of the optical cable. The antenna hub device is configured to receive the combined optical signal and to convert the optical carrier signals thereof to RF signals, amplify the RF signals, and transmit the RF signals to one or more antennas.

A high speed split receiver interface system for sensing a series of external signals, the system including: a series of remote radio head units for receiving a sensed signal in an analog electric form, each of the remote radio head units converting their sensed signal to a corresponding digital electrical form and then to a corresponding optical data form for dispatch over an optical data interconnection; at least one optical interconnect interconnecting each remote radio head unit with a baseband unit; a first baseband unit interconnecting the series of remote head units corresponding optical interconnects, and including a converter for conversion of the received optical signals to corresponding electrical digital form and down sampling the optical signals to corresponding down sampled signals, a memory store for storing the down sampled signals, and an external network interface for transmission of the saved signals to an external device.

Disclosed are a method and apparatus for acquiring an uplink bit error rate of a radio remote unit. The method comprises: recovering, by a vector signal generator, baseband data from an uplink baseband optical signal received from a radio remote unit; performing channel decoding on the baseband data, to obtain a decoded pseudo-noise (PN) sequence; and comparing the decoded PN sequence with a PN sequence locally transmitted by the vector signal generator, to obtain an uplink bit error rate of the radio remote unit.

A terminal (1050) includes a light receiver (151) that receives a light signal emitted by an apparatus (1000), the light signal including an identifier (SSID) of at least one base station (470); a receiver (153) that performs a reception process on the received light signal to output reception data; a data analyzer (155) that selects one base station based on the identifier of the at least one base station that is included in the reception data; and a radio device (453) that establishes a wireless connection with the selected base station (470) by using the identifier of the base station (470) and wirelessly communicates with the base station (470).

To n antenna elements of the base station, n wavelengths set at predetermined intervals in a range in which chromatic dispersion in an optical fiber between accommodation and base stations can be regarded as constant are assigned. The accommodation station adjusts the phases of optical signals of the wavelengths or modulated signals that modulate the optical signals such that the amounts of phase shift of their RF signals are at predetermined intervals. The accommodation station transmits beacon signals multiple times while varying a transmission phase shift interval α.sub.1 and the terminal transmits beacon number information of a beacon signal selected based on received power multiple times. The accommodation station varies a reception phase shift interval α.sub.2 for each piece of beacon number information to determine a reception phase shift interval α.sub.2 which maximizes the received power and determines the transmission phase shift interval α.sub.1 based on the beacon number information received from the terminal.