Techniques are disclosed for determining propagation delay of a first path and or of a second path which connect a first transceiver unit associated with a first clock to a second transceiver unit associated with a second clock in a communications network, based on a first time reference representing a time of transmission of a first signal from the first transceiver unit, a second time reference representing the time of receipt of the first signal at the second transceiver unit, a third time reference representing a time of transmission of a reply to the second signal from the second transceiver unit, and a fourth time reference representing the time of receipt of the reply to the second signal at the first transceiver unit.

Structures of a transmission apparatus and a reception apparatus using a mobile fronthaul that transmit and receive a frequency synchronization signal and a management control signal using at least one of in-band signaling and wavelength division multiplexing (WDM) in a single band or multiple bands of a mobile fronthaul using an intermediate frequency-over-fiber (IFoF) based analog transmission scheme.

In one embodiment, a distributed antenna system comprises: a master unit configured to receive a base station downlink radio frequency signal and to transmit a base station uplink radio frequency signal; and at least one remote antenna unit that is communicatively coupled to the master unit using at least one cable, the remote antenna unit configured to radiate a remote downlink radio frequency signal and to receive a remote uplink radio frequency signal; wherein the master unit comprises: a controller; and a respective interface to couple the controller to a first operator control panel; wherein the at least one remote antenna unit comprises: a controller; and a respective interface to couple the controller to a second operator control panel; wherein the master unit controller and the remote unit controller synchronize at least some information between the first and second operator control panels over the at least one cable.

An electromagnetic signal transport and distribution system simultaneously transports over one single mode fiber various programming specifically requested by multiple users in multiple locations while simultaneously offering bidirectional communications with a public network.

In one embodiment, a distributed antenna system comprises: at least one master unit; at least one remote antenna unit communicatively coupled via a switch to the master unit by a primary cable and a secondary cable both coupled to the switch, the remote antenna unit comprising a compensating link check module that outputs a control signal to the switch, wherein the switch selects between the primary and secondary cable in response to the control signal; wherein the compensating link check module controls the switch to momentarily select the secondary cable to perform a link check during which the remote unit measures a quality metric of a downlink signal received via the secondary cable; and upon initiation of the link check, the compensating link check module adjusts an attenuation of the downlink signal received on the secondary cable by loading calibration settings for the secondary cable into a compensation attenuator.

An optical transmitter includes: an amplitude control circuit, an E/O (Electrical-to-Optical) circuit, a detector and an optical power control circuit. The amplitude control circuit controls an amplitude of an input electric signal to generate a constant amplitude electric signal. The E/O circuit generates a modulated optical signal from the constant amplitude electric signal by a direct modulation. The detector detects an amplitude modulation component of the input electric signal. The optical power control circuit controls a power of the modulated optical signal based on the amplitude modulation component detected by the detector.

There is presented mechanisms for obtaining information for determining beamforming weights for terminal devices. A method is performed by an RE of an access node. The RE has an interface to an REC of the access node. The method comprises obtaining beamforming information per direction from the REC over the interface. The method comprises transforming the beamforming information per direction to beamforming information per antenna, the beamforming information per antenna representing the beamforming weights. The method comprises applying the beamforming weights.

A conversion unit configured for downconverting a RF radio signal from a first RF band to a first LF band, and up-converting an electric signal from a second LF band to a second RF band; the LF and RF bands have same bandwidth, while RF bands are centered on central frequencies being higher than the LF central frequencies of the LF bands. The conversion unit selects the copper cable link and the first LF band on which transmitting the downconverted RF signal according to a predetermined criteria between a plurality of RF frequency bands and the copper cable links. Moreover, the conversion unit selects the RF connection and the second RF band on which transmitting the upconverted LF signal according to a predetermined criteria between said plurality of RF connections and a plurality of RF bands.

A method is proposed of arranging, in a mobile communication network, transmission of data between user equipment and at least one base station including a central unit and at least one remote unit associated therewith. The method includes at a transmitting side including the remote unit or the central unit, quantizing the data according to a quantization bit number, and transmitting, over a fronthaul link between the transmitting side and a receiving side including the central unit or the remote unit, respectively, the quantized data to the receiving side. The method further includes, at the central unit: determining the quantization bit number, wherein the determining including varying in time the quantization bit number according to network information available at the central unit, and communicating to the at least one remote unit the determined quantization bit number.

A host device uses an intermediate frequency determined based on frequencies of a second-order nonlinear intermodulation distortion component and a harmonic component which are generated in an analog optical link connected to the host device, for example, an analog optical link of a distributed antenna system (DAS), and precompensates for the second-order nonlinear intermodulation distortion component and the harmonic component generated in the analog optical link.