Systems and methods that implement dynamically-switchable optical cables are described. One method includes a first terminal receiving one or more transmit high-speed electrical signals and one or more first low-speed electrical signals by a first terminal from a communication signal source. The first terminal may perform a first analysis on the first low-speed electrical signals, and determine a transmission direction based on the first analysis. A second terminal may receive or more second low-speed electrical signals by a second terminal from a communication signal sink. The second terminal may perform a second analysis the second low-speed electrical signals, and determine a reception direction based on the second analysis. The first terminal may convert the transmit high-speed electrical signals into high-speed optical signals, and transmit the high-speed optical signals to the second terminal via an optical communication channel.

Dynamically-switchable optical cables are described. One aspect includes a first terminal and a second terminal, each including an HDMI high-speed electrical interface. Each terminal may include a hot-plug signal analysis unit configured to receive one or more HDMI hot-plug detect signals, analyze the HDMI hot-plug detect signals, and determine if the associated terminal is connected to one of an HDMI signal source or an HDMI signal sink. Each terminal may include a signal transmitting unit electrically connected to the respective HDMI high-speed electrical interface, and a signal receiving unit electrically connected to the respective HDMI high-speed electrical interface. The optical cable may include a first optical communication channel connecting an output of the first signal transmitting unit to an input of the second signal receiving unit, and a second optical communication channel connecting an output of the second signal transmitting unit to an input of the first signal receiving unit.

A wireless radio frequency conversion system is disclosed. The wireless radio frequency conversion system includes a wireless radio frequency transmit-receive device, a first conversion device, at least one optical fiber, a second conversion device, and a wireless radio frequency transmission device. The wireless radio frequency transmit-receive device performs a conversion and a transmit-receive manner to at least one radio frequency signal and at least one data signal. The first conversion device performs a conversion to the at least one data signal and at least one optical signal. The optical fiber transmits the at least one optical signal. The second conversion device performs a conversion to the at least one optical signal and the at least one data signal. The wireless radio frequency transmission device performs a conversion and a transmit-receive manner to the at least one data signal and the at least one terminal signal.

A moving body-mounted communication system includes an internal connector, a third transmission line and a first information transmitting and receiving device. The internal connector is mounted in a moving body and connected to an external connector which is connected to a second transmission line. The third transmission line is arranged in the moving body and connected to the internal connector. The first information transmitting and receiving device is connected to the third transmission line. Information is transferred between a first transmission line used in an information and communication network outside the moving body and the second transmission line, and is transferred between the second transmission line and the third transmission line, without performing conversion of the information form of the information between light and electricity.

Embodiments of this application provide a central unit, a remote unit, a small cell system, and a communication method. A digital-to-analog conversion (DAC) module and an analog-to-digital conversion (ADC) module are disposed in the central unit, so that the central unit transmits an analog optical signal to the remote unit. When the central unit transmits the analog optical signal to a plurality of remote units, because a processing delay of an analog component in analog transmission is usually at a nanosecond level, and a total delay formed by a path transmission delay and the processing delay fluctuates slightly or even is fixed, synchronization of the plurality of remote units can be easily implemented in the central unit through calibration. Therefore, it is possible to easily implement a distributed MIMO function.

A fixed wireless access network provides for high-frequency data links between aggregation nodes and endpoint nodes. The system further provides for lower frequency wireless data links, which have carrier frequencies less than high-frequency wireless data links. These lower frequency links provide for auxiliary communications between the aggregation nodes and one or more endpoint nodes. During normal operation, the nodes exchange packet data via the high-frequency data links. However, when impairment of the high-frequency data links is detected, the nodes direct the packet data over the low-frequency data links instead until the high-frequency data links are no longer impaired.

An analog distributed antenna system having a set of small cells as a signal source is provided. A proposed cellular communication system includes an upper small cell unit including upper protocol processors configured to process an upper first part of a protocol stack of a small cell, a lower small cell unit including lower protocol processors configured to process a remaining second part of the protocol stack of the small cell, and a first matching switch configured to respectively match the lower protocol processors to a plurality of remote units. According to one aspect, the cellular communication system includes a common controller configured to control activation of the plurality of upper protocol processors of the upper small cell unit and the plurality of lower protocol processors of the lower small cell unit according to a required service capacity and appropriately control an operation of the first matching switch.

A method for controlling data transmission and reception and an application system thereof are provided. In the method, the peer-to-peer communication system is initialized to set each communication unit in the peer-to-peer communication system to be in a data receiving state. A communication host controls, according to a communication status of the peer-to-peer communication system, a controlled electrical connection path between the communication host and a communication interface to the communication transmission path, to work in a mode allowing data transmission from the communication slave to a communication host side of the controlled electrical connection path, or a mode allowing data transmission from the communication host side of the controlled electrical connection path to the communication slave.

An optical transmission system transmits a Radio Frequency (RF) signal by a frequency division multiplexing method. The optical transmission system includes a Transmitter Optical SubAssembly (TOSA), an optical fiber, and a Receiver Optical SubAssembly (ROSA). The TOSA includes a surface emitting laser diode configured to be capable of emitting light at output of 0.8 mW or more. In the optical transmission system including the surface emitting laser diode, a noise index obtained by a measurement method including a predetermined step is 10.0 dBμV or less.

Grid of beams (GoB) adaptation in a wireless communications circuit, particularly for a wireless communications system (WCS), is disclosed. The wireless communications circuit may be provided in the WCS to provide radio frequency (RF) coverage in a wireless communications cell. In this regard, an antenna array is provided in the wireless communications circuit to radiate the GoB, which includes a number of RF beams corresponding to an RF communications signal(s), in the wireless communications cell. In examples discussed herein, the wireless communications circuit can be configured to detect a coverage condition change in the wireless communications cell and modify the GoB accordingly. By adapting the GoB to the coverage condition change, it may be possible to reduce processing overhead and improve resource usage, data throughput, and system adaptability of the wireless communications circuit, thus helping to optimize RF coverage in the wireless communications cell.