A method and apparatus may be used in wireless communications. The apparatus may be an access point (AP), and may transmit a power save frame. The power save frame may include one or more Uplink (UL) Transmission Times (ULT)s. The apparatus may determine that a station (STA) did not transmit during its respective ULT. The AP may transmit another power save frame. The other power save frame may include a modified ULT. The modified ULT may be for a STA that did not transmit during its respective ULT. The other power save frame may include an unmodified ULT. The unmodified ULT may be for a STA that did not transmit.

A method and apparatus may be used in wireless communications. The apparatus may be an access point (AP), and may transmit a power save frame. The power save frame may include one or more Uplink (UL) Transmission Times (ULT)s. The apparatus may determine that a station (STA) did not transmit during its respective ULT. The AP may transmit another power save frame. The other power save frame may include a modified ULT. The modified ULT may be for a STA that did not transmit during its respective ULT. The other power save frame may include an unmodified ULT. The unmodified ULT may be for a STA that did not transmit.

The present invention discloses a method for processing a preamble sequence and header for a data packet, comprising the following steps of: using a bit sequence of a fixed pattern to replace a scrambled pseudo-random bit sequence in a SYNC field in the preamble sequence, and spreading the SYNC field by a Barker code; extending a length of a spreading code and spreading an SFD field in the preamble sequence by the extended spreading code; and extending a length of a spreading code and spreading a header field by the extended spreading code. The present invention may significantly improve the performance of reception and detection for the preamble sequence (the SYNC field and the SFD field) and the PLCP header field, better overcome long-distance channel conditions, enhance the signal stability of transmission; and meanwhile the present invention is easy to implement and only requires little modifications to the circuit of a conventional Wi-Fi device.

Various examples relate to a concept for generating and using a preamble for transmissions in a point-to-multipoint network, such as a Passive Optical Network (PON). A preamble generation apparatus for generating a preamble for a communication over an optical network comprises circuitry that is configured to generate a first subsection of the preamble, the first subsection of the preamble comprising a repetitive signal pattern. The preamble generation apparatus is configured to generate a second subsection of the preamble subsequent to the first subsection, the second subsection comprising a pseudorandom signal sequence.

Disclosed are a time synchronization method, a time synchronization device, a time synchronization apparatus and a storage medium. The method includes: periodically generating, by a local device, a synchronization request signal, and determining a first reference ID of the local device; sending the synchronization request signal and the first reference ID to peer devices; receiving a second reference ID and time information sent from each peer device through a communication link; and updating time of the local device according to the time information transmitted from a calibration link, the calibration link being a corresponding communication link of a target reference ID in second reference IDs sent from the peer devices.

A baseline difference is determined between a slave line card time stamp corresponding to a slave line card frame sync signal and a master line card time stamp corresponding to a master line card frame sync signal. The slave line card generates subsequent slave line card time stamps for subsequent slave line card frame sync signals and the master line card generates subsequent master line card time stamps for subsequent master line card frame sync signals. Current differences are determined between subsequent slave line card time stamps and the subsequent master line card time stamps and the current differences are compared to the baseline difference. When a mismatch difference occurs (current difference differs from the baseline difference), the mismatch difference causes a phase-locked loop in the master line card to be adjusted or an offset to be provided to the master line card time of day counter.

A baseline difference is determined between a slave line card time stamp corresponding to a slave line card frame sync signal and a master line card time stamp corresponding to a master line card frame sync signal. The slave line card generates subsequent slave line card time stamps for subsequent slave line card frame sync signals and the master line card generates subsequent master line card time stamps for subsequent master line card frame sync signals. Current differences are determined between subsequent slave line card time stamps and the subsequent master line card time stamps and the current differences are compared to the baseline difference. When a mismatch difference occurs (current difference differs from the baseline difference), the mismatch difference causes a phase-locked loop in the master line card to be adjusted or an offset to be provided to the master line card time of day counter.

The invention relates to a technique for performing a random access procedure over a radio interface, for example between a mobile terminal and a radio base station of a mobile network. A method aspect of the invention comprises the steps of transmitting a synchronization request for synchronization information; receiving synchronization information in response to the synchronization request; and transmitting, based on at least one transmission parameter adjusted in accordance with the synchronization information, a resource request for data transmission resources.

Methods, systems, and devices for wireless communication are described. A wireless communications system may support techniques for using non-staggered reference signals to increase the efficiency of the system and reduce the complexity of channel estimation. A base station may schedule a transmission to a user equipment (UE) including pilot tones mapped to a first symbol and a second symbol. In some cases, the pilot tones on the first and second symbols may be non-contiguous, and the base station may scramble the pilot tones on the first and second symbols according to the same scrambling sequence. In other cases, the pilot tones on the first and second symbols may be contiguous, and the pilot tones may be scrambled according to the same or different scrambling sequences. These techniques may result in reduced complexity for interference estimation and channel estimation at a UE.

A baseline difference is determined between a slave line card time stamp corresponding to a slave line card frame sync signal and a master line card time stamp corresponding to a master line card frame sync signal. The slave line card generates subsequent slave line card time stamps for subsequent slave line card frame sync signals and the master line card generates subsequent master line card time stamps for subsequent master line card frame sync signals. Current differences are determined between subsequent slave line card time stamps and the subsequent master line card time stamps and the current differences are compared to the baseline difference. When a mismatch difference occurs (current difference differs from the baseline difference), the mismatch difference causes a phase-locked loop in the master line card to be adjusted or an offset to be provided to the master line card time of day counter.