A method, an apparatus and a system for transmitting upstream burst data in a passive optical network system. Delimitation of end of upstream burst data is realized in the method. The method includes: transmitting a sync pattern sequence and a burst delimiter after turning on a laser; transmitting data to be sent; and transmitting an end-of-burst delimiter after the transmitting of data to be sent is finished. A method for receiving upstream burst data and a related apparatus and system are also provided in the embodiments of the invention.

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.

System, methods and apparatus are described that support multimode operation of a data communication interface. A method includes initializing a scrambler with a first pseudo-random binary sequence (PRBS) seed word after receiving a first sync word, the first sync word preceding a first packet, using the scrambler and the first PRBS seed word to scramble a first copy of a packet header that succeeds the first sync word in the first packet, initializing the scrambler with a second PRBS seed word after scrambling the first copy of the packet header, the second sync word succeeding the first copy of the packet header in the first packet, using the scrambler and the second PRBS seed word to scramble a second copy of the packet header that succeeds the second sync word in the first packet.

Method for wire-free transmission of data packets between network nodes in a control network, wherein the data packets each have a preamble for synchronization, which preamble consists of a predetermined number of preamble symbols; wherein, in a first operating mode (FIG. 5a), each preamble-subsymbol (Cj, Cj+1) of a preamble symbol in the preamble is coded by the phase angle of a transmitted single signal pulse; wherein, in a second operating mode (FIG. 5b), in order to increase the signal recognition performance, for the preamble which is transmitted in the data packet, a signal pulse sequence (SIF) for coding the preamble-subsymbol (Cj, Cj+1) is transmitted instead of a single signal pulse, in which signal pulse sequence (SIF) the single signal pulse is transmitted repeatedly.

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.

This application discloses a transmission method for optical communication. The method is applicable to a plurality of scenarios of over 400 Gbps (including 600 Gbps, 800 Gbps, and the like), such as a metropolitan area network, a backbone network, and data center interconnection. The method includes: generating a frame including a plurality of symbols, where in a polarization direction, the frame includes N.sub.FAW frame alignment word symbols, N.sub.PS pilot symbols, and N.sub.RES reserved symbols, one symbol in every M symbols in the frame is a pilot symbol, and N.sub.FAW+N.sub.RES=M or N.sub.FAW+N.sub.RES+1=M; and each of the frame alignment word symbols and the pilot symbols is one of AAj, A+Aj, AAj, and A+Aj, and A is a real number; and transmitting the frame.

A method including receiving at a synchronizing node a first reference frame from a first reference node at a first time and storing a first time value representing the first time, and calculating a timing estimator by subtracting a minimum time value, representing the distance from the synchronizing node to the first reference node, from the first time value. The method includes receiving at the synchronizing node a second reference frame at a second time and transmitting from the synchronizing node to the first reference node a short timing contention time frame. The method includes receiving at the synchronizing node from the first reference node an arrival time value representing the time at which the first reference node received the short timing contention frame and calculating a time drift from the first arrival time value and the second time value and adjusting the timing estimator based on the time drift.

A transmission apparatus includes: a plurality of logical lanes; a receiver configured to receive a signal including synchronization information of a frame; a distributor configured to divide data included in the received signal into frame elements and cause the plurality of logical lanes to store the data; and a transmitter configured to transmit the data stored in the logical lanes to lines corresponding to the logical lanes. When the data is stored in the plurality of logical lanes, the distributor groups the logical lanes into a plurality of groups and associates the frame elements with the synchronization information.

A method for transmitting a signal for cell searching in a mobile communication system having a multi-cell environment includes transmitting the signal to one or more receiving party devices within a cell, wherein the signal is used for a synchronization of the one or more receiving party devices within the cell, the signal is defined by a combination of a first code sequence derived from a first index and a second code sequence derived from a second index, and an identity of the cell is used for defining the combination of the first code sequence and the second code sequence.

A method for transmitting useful information between a transmitting terminal and a receiving terminal connected via a transmission channel. The transmitting terminal defines control information for the useful information, and searches in an association table, which is accessible from the transmitting terminal, for a frame-synchronization word associated with the control information. The transmitting terminal generates a frame of data from the useful information, and transmits, over the transmission channel, a data stream that includes the frame-synchronization word and the frame of data.