Abstract: The present disclosure relates to random access preamble transmission methods, apparatuses, and storage mediums. In one example method, a terminal device determines, based on a target sub-coverage area to which the terminal device belongs in a preset coverage area of a network device, target random access preamble format information corresponding to the target sub-coverage area. Then, the terminal device sends, to the network device on a target time-frequency resource indicated by target random access preamble time-frequency resource information corresponding to the target random access preamble format information, a random access preamble corresponding to the target random access preamble format information.

Abstract: Example communication methods and apparatus are described. In one example method, a terminal receives a first information by using a serving beam, where the first information indicates a delay compensation parameter corresponding to a target beam. The target beam and the serving beam are different beams. The terminal determines, based on a full timing advance and the delay compensation parameter corresponding to the target beam, a differential timing advance corresponding to the target beam.

Abstract: The present disclosure relates to access methods and apparatuses. In one example method, a terminal device determines, based on whether a first frequency offset parameter is in a frequency offset parameter range, whether to access a first cell. If the first frequency offset parameter is in the frequency offset parameter range, a current location of the terminal device is not at an edge of the cell. Otherwise, the current location of the terminal device may be at the edge of the cell.

Abstract: The disclosure provides satellite communication methods and related devices. One example method includes that a device receives a first common timing advance (TA) parameter and a first common TA change amount calculation parameter, where the first common TA parameter is used to obtain a first common TA, and the first common TA change amount calculation parameter is used to update the first common TA to obtain an updated common TA. The device sends a random access preamble by using the updated common TA.

Abstract: The present disclosure relates to network switching methods and apparatuses. in one example method, a beam that currently provides a service for a terminal device is a first beam. The first beam is generated by a first network device. The first network device obtains user information of the terminal device, and obtains switching information based on the user information. After the first network device sends the switching information to the terminal device, the terminal device can perform beam switching based on the switching information.

Abstract: The present disclosure relates to communication methods and apparatuses. In one example method, a terminal device receives first information from an access device, and determines a first bandwidth part (BWP) of an access beam of the terminal device based on the received first information and a second BWP configured for the access beam of the terminal device. Then, the terminal device communicates with the access device in the determined first BWP by using the access beam. The first information indicates a relationship between the first BWP and the second BWP. The second BWP is a dedicated BWP configured for the access beam of the terminal device.

Abstract: This application discloses a random access preamble configuration method applicable to a satellite network and a communication apparatus. In the method, a random access preamble location offset and duration of a PRACH occasion can be flexibly configured based on features of a satellite system. The method includes: A receiving apparatus receives first indication information, where the first indication information includes indication information used to identify the random access preamble location offset at the physical random access channel PRACH occasion. The receiving apparatus transmits a random preamble based on the first indication information, where the random preamble includes a sequence part and a guard time. Because a communication distance is relatively long and a transmission delay difference between users is relatively large in a satellite communication system, time domain resources occupied by the PRACH occasion can be minimized by using this method.

Abstract: This application discloses a beam establishment method. A terminal apparatus obtains synchronization signal and PBCH blocks SSBs in a plurality of beams; then determines a target beam in the plurality of beams based on an association relationship between an SSB index and a first random access preamble, where the first random access preamble is determined based on a cyclic shift and/or an order of symbols; and finally sends the random access preamble by using the target beam, to initiate a random access request. A communication device receives the first random access preamble in the random access request sent by the terminal apparatus, and then determines, based on the association relationship, the target beam accessed by the terminal apparatus. According to embodiments of this application, the first random access preamble is determined based on the cyclic shift and/or the order of symbols.

Abstract: This application provides a random access method and apparatus, and a device. The network device obtains a first random access preamble length of a first terminal device and a second random access preamble length of a second terminal device, where a value of delay compensation performed by the network device when receiving a first random access preamble is different from a value of delay compensation performed by the network device when receiving a second random access preamble. The network device determines a first random access parameter of the first terminal device and a second random access parameter of the second terminal device based on the first random access preamble length and the second random access preamble length, where there is an overlapping part, in time domain, between a random access preamble indicated by the first random access parameter and a random access preamble indicated by the second random access parameter.

Abstract: This disclosure provides satellite communication methods and apparatuses. One example method includes that a terminal device determines a first time offset of a first random access response window based on a distance information between a satellite base station and the ground. Based on the first time offset and the first random access response window, the terminal device receives a random access response sent by the satellite base station.

Abstract: Provided are a method and device for video search, a terminal and a storage medium. The method includes: receiving a first event generated by triggering a first control in a video playback page; acquiring, in response to the first event, a current video image frame played in the video playback page when the first event is triggered; acquiring a first to-be-searched target positioned by a second control in the current video image frame and a first display position of the first to-be-searched target in the current video image frame, and displaying the second control on the first display position; and acquiring a first recommendation result corresponding to the first to-be-searched target, and displaying the first recommendation result in a search result page.

Abstract: Example satellite communication methods and example related devices are provided. One example satellite communication method includes generating a random access preamble sequence, where the random access preamble sequence includes a cyclic prefix, a sequence part, and a guard interval, the sequence part is obtained by performing frequency domain resource mapping and time-frequency transformation on a frequency domain sequence, and the frequency domain sequence is obtained based on a Zadoff-Chu (ZC) sequence and a mask sequence. The random access preamble sequence can then be output.

Abstract: This application discloses example signal sending methods and apparatuses, and example signal processing methods and apparatuses. One example method includes generating, by a terminal device, a channel sounding reference signal (SRS). The terminal device can then send the SRS to a target base station, where the target base station detects, by using the SRS, that a change range of an uplink timing location of the terminal device is not less than a length of one SRS symbol.

Abstract: One example method includes that a terminal device determines first random access information associated with a first synchronization broadcast block and associated with a beam parameter of a satellite beam, where the beam parameter is used to distinguish the satellite beam. The terminal sends a preamble to a satellite based on the first random access information. The satellite receives the preamble from the terminal, and determines the first random access information. The satellite determines the first SSB and the beam parameter of the satellite beam that are associated with the first random access information.

Abstract: The present disclosure relates to timing advance indication methods, communication apparatuses, and storage medium. In one example method, a first device determines a quantity of extended bits and a location of the extended bit of a timing advance (TA) instruction based on a subcarrier spacing of a second device. The first device sends the TA instruction to the second device, where the TA instruction includes the extended bit, and a quantity of bits of the TA instruction is greater than 12.

Abstract: This disclosure provides data processing methods. One example including a network device obtains target information that includes a transmission delay difference corresponding to a target beam or a target cell; determines a first preamble format based on the transmission delay difference, and then determines first configuration information used to indicate the first preamble format and a first set of random access occasions included in a random access period, where an interval between random access times included in the first set of random access occasions is greater than or equal to a preamble length corresponding to the first preamble format; and generates a corresponding first configuration index based on the first configuration information. The preamble formats required for different beams or cells can be determined based on transmission delay differences corresponding to the different beams or cells, and then configuration information of a random access occasion is further determined.

Abstract: The disclosure provides satellite communication methods and related devices. One example method includes generating a random access preamble sequence which includes a cyclic prefix, a sequence part, and a guard interval. The sequence part includes a subsequence A and a subsequence B, or the sequence part includes a subsequence C, and the subsequence C is a time domain superimposed sequence of a subsequence A and a subsequence B. The subsequence A includes at least one preamble symbol, the subsequence B includes at least one preamble symbol, and the subsequence A and the subsequence B are respectively generated by using ZC sequences of different root indexes, a quantity of subsequences A is m, a quantity of subsequences B is m or m?1, and m is a positive integer. The method further includes outputting the random access preamble sequence.

Abstract: The disclosure provides transmission methods and apparatuses. One example includes sending control signaling to a terminal device, to indicate the terminal device to send a physical uplink shared channel (PUSCH) on a first frequency band; and receiving the PUSCH sent by the terminal device on the first frequency band. The first frequency band includes at least one guard subcarrier. A quantity of the at least one guard subcarrier is determined based on a Doppler frequency shift of a beam covering the terminal device. The first frequency band is located on a frequency band corresponding to the beam.

Abstract: Example communication methods and apparatus are described. One example method includes generating a first signal and sending a first signal, where the first signal includes an orthogonal frequency division multiplexing (OFDM) symbol, a first-type cyclic prefix (CP), and a second-type CP. CP resources of the first-type CP include two types of CP resources: a first CP resource and a second CP resource. CP resources of the second-type CP include one type of CP resource, that is, the second CP resource. The first CP resource may be used to carry data that is different from data carried on the OFDM symbol. The second CP resource may be used to carry data that is the same as the data carried on the OFDM symbol.

Abstract: This application provides a satellite communication method and an apparatus. The method includes: receiving, by a terminal device, first information sent by a satellite, where the first information is used to indicate a first timing change rate range; measuring and obtaining, by the terminal device, a first downlink timing change rate; determining a first uplink timing change rate based on the first downlink timing change rate and the first timing change rate range; and performing uplink communication with the satellite based on the first uplink timing change rate. The method can effectively resolve a problem of uplink timing drift and improve uplink performance.