Patent Description:
In a communications system, time division duplex (time division duplexing, TDD) means that a signal is transmitted and received in different timeslots of a same frequency channel, and a receive channel is separated from a transmit channel in terms of time in TDD. Because a TDD scenario does not require paired frequencies, TDD may be conveniently configured on scattered frequency bands that are not easily used in a frequency division duplex (frequency division duplexing, FDD) scenario, so that spectrum flexibility can be achieved to some extent, and spectrum utilization can be effectively improved.

However, in the TDD scenario, because a quantity of downlink subframes on an anchor carrier is limited, to resolve a resource configuration problem, a SIB1 may indicate another SIB to be sent on a non-anchor carrier. When the another SIB is sent on the non-anchor carrier, a terminal device does not know a valid (valid) subframe configuration on the non-anchor carrier, and therefore the terminal device may receive the another SIB in an invalid (invalid) subframe. Consequently, the terminal device cannot receive the another SIB, and cannot work normally in the TDD scenario.

The document <NPL>, is an early standardization document with regard to TDD downlink aspects in LTE.

The document <NPL>, is also an early standardization document with regard to transmitting setup messages on anchor carriers and non-anchor carriers in LTE.

The document <NPL> is a further standardization document dealing with the scheduling of system information in LTE TDD mode. <CIT> relates to directing a UE via a first carrier to receive system information on a second carrier.

This application provides a communications method and apparatus, and a computer-readable storage medium, to determine a valid subframe on a non-anchor carrier. This problem is solved by the subject matter of the independent claims. Further implementation forms are provided in the dependent claims.

According to a first aspect, not covered by the invention, a communications method is provided, including: determining a valid subframe and an invalid subframe on an anchor carrier; determining at least one valid subframe on a non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier; and receiving another system information block SIB in the at least one valid subframe on the non-anchor carrier, where the another SIB is a system information block other than a SIB1.

According to the technical solution provided in this application, a terminal device receives the another SIB in the valid subframe on the non-anchor carrier. Therefore, it can be ensured that the terminal device correctly receives the another SIB, so that it is ensured that the terminal device can work normally in a TDD scenario. In addition, the terminal device can determine the at least one valid subframe on the non-anchor carrier without introducing new signaling, so that signaling overheads can be reduced.

Specifically, the anchor carrier may be a carrier for transmitting a PSS, an SSS, and a PBCH, and the non-anchor carrier may be a carrier for transmitting other information instead of a PSS, an SSS, and a PBCH.

The SIB1 is a system information block type, mainly carries at least one of information related to cell access and cell selection, scheduling information of another SIB block, or the like, and is a most important system information block.

In a possible implementation, the communications method includes: determining a valid downlink subframe and an invalid downlink subframe on the anchor carrier; determining at least one valid downlink subframe on the non-anchor carrier based on the valid downlink subframe and the invalid downlink subframe on the anchor carrier; and receiving another SIB in the at least one valid downlink subframe on the non-anchor carrier.

In a possible implementation, the communications method includes: determining a valid downlink subframe and a valid special subframe on the anchor carrier; determining at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier based on the valid downlink subframe and the valid special subframe on the anchor carrier; and receiving another SIB in the at least one valid downlink subframe and the at least one valid special subframe on the non-anchor carrier.

In a possible implementation, the communications method includes: determining the valid subframe and the invalid subframe on the anchor carrier; determining the at least one valid subframe on the non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier; determining at least one valid downlink subframe, or at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier based on an uplink-downlink subframe configuration on the non-anchor carrier and the at least one valid subframe on the non-anchor carrier; and receiving another SIB in the at least one valid downlink subframe, or in the at least one valid downlink subframe and the at least one valid special subframe on the non-anchor carrier. and receiving another SIB in the at least one valid downlink subframe, or in the at least one valid downlink subframe and the at least one valid special subframe on the non-anchor carrier.

In a possible implementation, the determining at least one valid subframe on a non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier includes: determining that a subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier.

Specifically, the correspondence may mean that super frames on the anchor carrier are in a one-to-one correspondence with super frames on the non-anchor carrier, radio frames on the anchor carrier are in a one-to-one correspondence with radio frames on the non-anchor carrier, and subframes on the anchor carrier are in a one-to-one correspondence with subframes on the non-anchor carrier. For example, a radio frame <NUM> on the anchor carrier corresponds to a radio frame <NUM> on the non-anchor carrier, and a radio frame <NUM> on the anchor carrier corresponds to a radio frame <NUM> on the non-anchor carrier. A subframe <NUM> in the radio frame <NUM> on the anchor carrier corresponds to a subframe <NUM> in the radio frame <NUM> on the non-anchor carrier, a subframe <NUM> in the radio frame <NUM> on the anchor carrier corresponds to a subframe <NUM> in the radio frame <NUM> on the non-anchor carrier, and by analogy, a subframe <NUM> in the radio frame <NUM> on the anchor carrier corresponds to a subframe <NUM> in the radio frame <NUM> on the non-anchor carrier.

In a possible implementation, the determining that a subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier includes: determining that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier and a subframe that is on the non-anchor carrier and that corresponds to a subframe for transmitting a target signal on the anchor carrier are the at least one valid subframe on the non-anchor carrier, where the target signal includes at least one of the following signals: a primary synchronization signal PSS, a secondary synchronization signal SSS, and a physical broadcast channel PBCH.

In a possible implementation, the target signal further includes the SIB1, and the SIB1 is transmitted on the anchor carrier.

In a possible implementation, on the anchor carrier, a subframe for transmitting the PSS in the target signal is a subframe <NUM>, a subframe for transmitting the SSS in the target signal is a subframe <NUM>, a subframe for transmitting the PBCH in the target signal is a subframe <NUM>, and a subframe for transmitting the SIB1 in the target signal is a subframe <NUM> or a subframe <NUM>.

Specifically, the subframe that is on the non-anchor carrier and that corresponds to the subframe for transmitting the target signal on the anchor carrier may mean that the subframe <NUM> for transmitting the PSS on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, the subframe <NUM> for transmitting the SSS on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, the subframe <NUM> for transmitting the PBCH on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, and the subframe <NUM> for transmitting the SIB1 on the anchor carrier corresponds to the subframe <NUM> on the non-anchor carrier or the subframe <NUM> for transmitting the SIB1 on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier.

In a possible implementation, the SIB1 is transmitted on the non-anchor carrier, and the determining that a subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier includes: determining that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier, and determining that a subframe for transmitting the SIB <NUM> on the non-anchor carrier is an invalid subframe on the non-anchor carrier.

In a possible implementation, the determining a valid subframe and an invalid subframe on an anchor carrier includes: receiving the SIB1, where the SIB1 includes first information, and the first information is used to indicate a valid subframe configuration on the anchor carrier; and determining the valid subframe and the invalid subframe on the anchor carrier based on the valid subframe configuration on the anchor carrier and a subframe for transmitting a first signal on the anchor carrier, where the first signal includes at least one of the following signals: a PSS, an SSS, a PBCH, and the SIB1.

According to a second aspect, a communications method is provided, including: receiving a system information block SIB1, where the SIB1 includes first information, and the first information is used to indicate a valid subframe configuration on a non-anchor carrier; determining at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the non-anchor carrier; and receiving another system information block SIB in the at least one valid subframe on the non-anchor carrier, where the another SIB is a system information block other than the SIB1.

According to the technical solution provided in this application, a terminal device receives the another SIB in the valid subframe on the non-anchor carrier. Therefore, it can be ensured that the terminal device correctly receives the another SIB, so that it is ensured that the terminal device can work normally in a TDD scenario.

In a possible implementation, the first information is further used to indicate a valid subframe configuration on an anchor carrier.

In this application, the first information may be reused, and the first information is used to indicate both the valid subframe configuration on the anchor carrier and the valid subframe configuration on the non-anchor carrier. Therefore, signaling overheads can be reduced.

In a possible implementation, the SIB1 further includes second information, and the second information is used to indicate the valid subframe configuration on the anchor carrier.

In this indication manner, a valid subframe and an invalid subframe on the non-anchor carrier can be accurately indicated, so that a resource waste can be avoided.

In a possible implementation, the first information occupies M bits, each bit in the M bits is used to indicate whether a subframe corresponding to the bit is a valid subframe or an invalid subframe on the non-anchor carrier, and M is a positive integer.

In a possible implementation, the M bits are <NUM> bits or <NUM> bits.

Specifically, the correspondence may mean that the M bits are in a one-to-one correspondence with subframes on the non-anchor carrier. For example, if the M bits are <NUM> bits, the correspondence means that the <NUM>st bit corresponds to a subframe <NUM> in a radio frame <NUM>, the <NUM>nd bit corresponds to a subframe <NUM> in the radio frame <NUM>, and by analogy, the <NUM>th bit corresponds to a subframe <NUM> in the radio frame <NUM>.

According to a third aspect, not covered by the invention, a communications method is provided, including: receiving a system information block SIB1, where the SIB1 includes first information and second information, the first information is used to indicate a valid subframe configuration on an anchor carrier, and the second information is used to indicate a valid subframe configuration of a subframe that is on a non-anchor carrier and that corresponds to an invalid subframe on the anchor carrier; determining at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the anchor carrier and the valid subframe configuration of the subframe that is on the non-anchor carrier and that corresponds to the invalid subframe on the anchor carrier; and receiving another SIB in the at least one valid subframe on the non-anchor carrier, where the another SIB is a system information block other than the SIB1.

According to the technical solution provided in this application, only a relatively small amount of information is required to indicate whether the subframe that is on the non-anchor carrier and that corresponds to the invalid subframe on the anchor carrier is a valid subframe or an invalid subframe, so that a valid subframe and an invalid subframe on the non-anchor carrier can be accurately determined by using relatively small signaling overheads.

According to a fourth aspect, not covered by the invention, a communications method is provided, including: determining a valid subframe and an invalid subframe on an anchor carrier; determining at least one valid subframe on a non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier; and sending another system information block SIB in the at least one valid subframe on the non-anchor carrier, where the another SIB is a system information block other than a SIB1.

According to the technical solution provided in this application, a network device determines the at least one valid subframe on the non-anchor carrier in a specific manner, and sends the another SIB in the at least one valid subframe on the non-anchor carrier. Therefore, it can be ensured that a terminal device correctly receives the another SIB, so that it is ensured that the terminal device can work normally in a TDD scenario. In addition, the network device determines the at least one valid subframe on the non-anchor carrier without introducing new signaling, so that signaling overheads can be reduced.

In a possible implementation, the communications method includes: determining a valid downlink subframe and an invalid downlink subframe on the anchor carrier; determining at least one valid downlink subframe on the non-anchor carrier based on the valid downlink subframe and the invalid downlink subframe on the anchor carrier; and sending another SIB in the at least one valid downlink subframe on the non-anchor carrier.

In a possible implementation, the communications method includes: determining a valid downlink subframe and a valid special subframe on the anchor carrier; determining at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier based on the valid downlink subframe and the valid special subframe on the anchor carrier; and sending another SIB in the at least one valid downlink subframe and the at least one valid special subframe on the non-anchor carrier.

In a possible implementation, the communications method includes: determining the valid subframe and the invalid subframe on the anchor carrier; determining the at least one valid subframe on the non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier; determining at least one valid downlink subframe, or at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier based on an uplink-downlink subframe configuration on the non-anchor carrier and the at least one valid subframe on the non-anchor carrier; and sending another SIB in the at least one valid downlink subframe, or in the at least one valid downlink subframe and the at least one valid special subframe on the non-anchor carrier.

In a possible implementation, on the anchor carrier, a subframe for transmitting the PSS in the target signal is a subframe <NUM>, a subframe for transmitting the SSS in the target signal is a subframe <NUM>, a subframe for transmitting the PBCH in the target signal is a subframe <NUM>, and a subframe for transmitting the SIB <NUM> in the target signal is a subframe <NUM> or a subframe <NUM>.

Specifically, the subframe that is on the non-anchor carrier and that corresponds to the subframe for transmitting the target signal on the anchor carrier may mean that the subframe <NUM> for transmitting the PSS on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, the subframe <NUM> for transmitting the SSS on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, the subframe <NUM> for transmitting the PBCH on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, and the subframe <NUM> for transmitting the SIB <NUM> on the anchor carrier corresponds to the subframe <NUM> on the non-anchor carrier or the subframe <NUM> for transmitting the SIB <NUM> on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier.

In a possible implementation, the SIB1 is transmitted on the non-anchor carrier, and the determining that a subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier includes: determining that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier, and determining that a subframe for transmitting the SIB1 on the non-anchor carrier is an invalid subframe on the non-anchor carrier.

In a possible implementation, the determining a valid subframe and an invalid subframe on an anchor carrier includes: sending the SIB1, where the SIB1 includes first information, and the first information is used to indicate a valid subframe configuration on the anchor carrier; and determining the valid subframe and the invalid subframe on the anchor carrier based on the valid subframe configuration on the anchor carrier and a subframe for transmitting a first signal on the anchor carrier, where the first signal includes at least one of the following signals: a PSS, an SSS, a PBCH, and the SIB1.

According to a fifth aspect, a communications method is provided, including: sending a system information block SIB1, where the SIB1 includes first information, and the first information is used to indicate a valid subframe configuration on a non-anchor carrier; determining at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the non-anchor carrier; and sending another system information block SIB in the at least one valid subframe on the non-anchor carrier, where the another SIB is a system information block other than the SIB1.

According to the technical solution provided in this application, a network device determines the at least one valid subframe on the non-anchor carrier in a specific manner, and sends the another SIB in the valid subframe on the non-anchor carrier. Therefore, it can be ensured that a terminal device correctly receives the another SIB, so that it is ensured that the terminal device can work normally in a TDD scenario.

According to a sixth aspect, not covered by the invention, a communications method is provided, including: sending a system information block SIB1, where the SIB1 includes first information and second information, the first information is used to indicate a valid subframe configuration on an anchor carrier, and the second information is used to indicate a valid subframe configuration of a subframe that is on a non-anchor carrier and that corresponds to an invalid subframe on the anchor carrier; determining at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the anchor carrier and the valid subframe configuration of the subframe that is on the non-anchor carrier and that corresponds to the invalid subframe on the anchor carrier; and sending another SIB in the at least one valid subframe on the non-anchor carrier, where the another SIB is a system information block other than the SIB1.

According to a seventh aspect, not covered by the invention, a communications apparatus is provided, including a unit configured to perform the method according to the first aspect and any implementation of the first aspect.

According to an eighth aspect, not covered by the invention, a communications apparatus is provided, including a unit configured to perform the method according to the second aspect and any implementation of the second aspect.

According to a ninth aspect, not covered by the invention, a communications apparatus is provided, including a unit configured to perform the method according to the third aspect and any implementation of the third aspect.

According to a tenth aspect, not covered by the invention, a communications apparatus is provided, including a unit configured to perform the method according to the fourth aspect and any implementation of the fourth aspect.

According to an eleventh aspect, not covered by the invention, a communications apparatus is provided, including a unit configured to perform the method according to the fifth aspect and any implementation of the fifth aspect.

According to a twelfth aspect, not covered by the invention, a communications apparatus is provided, including a unit configured to perform the method according to the sixth aspect and any implementation of the sixth aspect.

According to a thirteenth aspect, not covered by the invention, a communications apparatus is provided. The communications apparatus includes a processor and a transceiver, and is configured to perform the method according to the first aspect and any implementation of the first aspect.

According to a fourteenth aspect, not covered by the invention, a communications apparatus is provided. The communications apparatus includes a processor and a transceiver, and is configured to perform the method according to the second aspect and any implementation of the second aspect.

According to a fifteenth aspect, not covered by the invention, a communications apparatus is provided. The communications apparatus includes a processor and a transceiver, and is configured to perform the method according to the third aspect and any implementation of the third aspect.

According to a sixteenth aspect, not covered by the invention, a communications apparatus is provided. The communications apparatus includes a processor and a transceiver, and is configured to perform the method according to the fourth aspect and any implementation of the fourth aspect.

According to a seventeenth aspect, not covered by the invention, a communications apparatus is provided. The communications apparatus includes a processor and a transceiver, and is configured to perform the method according to the fifth aspect and any implementation of the fifth aspect.

According to an eighteenth aspect, not covered by the invention, a communications apparatus is provided. The communications apparatus includes a processor and a transceiver, and is configured to perform the method according to any of the previous aspects.

According to a nineteenth aspect, not covered by the invention, a computer-readable storage medium is provided. The computer-readable storage medium is used to store program code executed by a device, and the program code includes an instruction used to perform the method according to the first aspect and all the implementations of the first aspect.

According to a twentieth aspect, not covered by the invention, a computer-readable storage medium is provided. The computer-readable storage medium is used to store program code executed by a device, and the program code includes an instruction used to perform the method according to the second aspect and all the implementations of the second aspect.

According to a twenty-first aspect, not covered by the invention, a computer-readable storage medium is provided. The computer-readable storage medium is used to store program code executed by a device, and the program code includes an instruction used to perform the method according to the third aspect and all the implementations of the third aspect.

According to a twenty-second aspect, not covered by the invention, a computer-readable storage medium is provided. The computer-readable storage medium is used to store program code executed by a device, and the program code includes an instruction used to perform the method according to the fourth aspect and all the implementations of the fourth aspect.

According to a twenty-third aspect, not covered by the invention, a computer-readable storage medium is provided. The computer-readable storage medium is used to store program code executed by a device, and the program code includes an instruction used to perform the method according to the fifth aspect and all the implementations of the fifth aspect.

According to a twenty-fourth aspect, not covered by the invention, a computer-readable storage medium is provided. The computer-readable storage medium is used to store program code executed by a device, and the program code includes an instruction used to perform the method according to the sixth aspect and all the implementations of the sixth aspect.

According to a twenty-fifth aspect, not covered by the invention, a computer program product is provided. The computer program product includes computer program code, and when the computer program code is run on a computer, the computer is enabled to perform the method according to the first aspect and any implementation of the first aspect.

According to a twenty-sixth aspect, not covered by the invention, a computer program product is provided. The computer program product includes computer program code, and when the computer program code is run on a computer, the computer is enabled to perform the method according to the second aspect and any implementation of the second aspect.

According to a twenty-seventh aspect, not covered by the invention, a computer program product is provided. The computer program product includes computer program code, and when the computer program code is run on a computer, the computer is enabled to perform the method according to the third aspect and any implementation of the third aspect.

According to a twenty-eighth aspect, not covered by the invention, a computer program product is provided. The computer program product includes computer program code, and when the computer program code is run on a computer, the computer is enabled to perform the method according to the fourth aspect and any implementation of the fourth aspect.

According to a twenty-ninth aspect, not covered by the invention, a computer program product is provided. The computer program product includes computer program code, and when the computer program code is run on a computer, the computer is enabled to perform the method according to the fifth aspect and any implementation of the fifth aspect.

According to a thirtieth aspect, not covered by the invention, a computer program product is provided. The computer program product includes computer program code, and when the computer program code is run on a computer, the computer is enabled to perform the method according to the sixth aspect and any implementation of the sixth aspect.

According to a thirty-first aspect, not covered by the invention, a chip is provided, including a processor and a memory. The memory is configured to store a computer program. The processor is configured to invoke and run the computer program in the memory. The computer program is used to implement the methods in the foregoing aspects.

According to a thirty-second aspect, not covered by the invention, a communications system is provided. The communications system includes the terminal device according to the seventh aspect, the ninth aspect, the tenth aspect, or the eleventh aspect and the network device according to the eighth aspect, the twelfth aspect, the thirteenth aspect, or the fourteenth aspect.

<FIG> shows a wireless communications system <NUM> to which an embodiment of this application is applied. The wireless communications system <NUM> may include a network device <NUM>. The network device <NUM> may be a device communicating with a terminal device <NUM>. The network device <NUM> may provide communication coverage for a specific geographical area, and may communicate with the terminal device <NUM> located in the coverage.

<FIG> shows one network device and two terminal devices as an example. Optionally, the communications system <NUM> may include a plurality of network devices, and another quantity of terminal devices may be included in coverage of each network device. This is not limited in this embodiment of this application.

Optionally, the wireless communications system <NUM> may further include other network entities such as a network controller and a mobility management entity. This is not limited in the embodiments of this application.

It should be understood that the technical solutions in the embodiments of this application may be applied to various communications systems, for example, a global system for mobile communications (global system of mobile communication, GSM), a code division multiple access (code division multiple access, CDMA) system, a wideband code division multiple access (wideband code division multiple access, WCDMA) system, a general packet radio service (general packet radio service, GPRS), a long term evolution (long term evolution, LTE) system, a long term evolution-advanced (advanced long term evolution, LTE-A) system, a universal mobile telecommunications system (universal mobile telecommunication system, UMTS), a new radio (new radio access technology, NR) system, and <NUM>.

With advent of the smart city and big data era, wireless communication implements connectivity of everything. Currently, there are a large quantity of connections between things. Most of these connections between things are carried in short-distance communications technologies such as Bluetooth and Wi-Fi, instead of carrier mobile networks. To meet transmission requirements of different internet of things (internet of things, IoT) services, the 3rd generation partnership project (the 3rd generation partnership project, 3GPP) carries out technical research on enhancing functions of a mobile communications network based on service features of the internet of things and characteristics of the mobile communications network, to adapt to booming service requirements of the internet of things.

Cellular network-based narrowband internet of things (narrow band-IoT, NB-IoT) becomes an important branch of the internet of everything. NB-IoT is deployed on a cellular network and consumes only a bandwidth of about <NUM>. NB-IoT can be directly deployed on a GSM network, a UMTS network, or an LTE network, to reduce NB-IoT deployment costs and achieve smooth upgrade.

It should be further understood that, in the embodiments of this application, the terminal may include but is not limited to a terminal device applied to the internet of things, for example, may be a terminal device (which may be referred to as an "NB-IoT terminal") that accesses NB-IoT: a smart meter reading device, a logistics tracking device, or an environment monitoring device. The terminal may further include but is not limited to a mobile station (mobile station, MS), a mobile terminal (mobile terminal), a mobile telephone (mobile telephone), user equipment (user equipment, UE), a handset (handset), portable equipment (portable equipment), and the like. The terminal device may communicate with one or more core networks through a radio access network (radio access network, RAN). For example, the terminal device may be a mobile phone (or referred to as a "cellular" phone), or a computer having a wireless communication function. The terminal device may alternatively be a portable, pocket-sized, handheld, computer built-in, or vehicle-mounted mobile apparatus.

In the embodiments of this application, the network device may be an access network device, for example, may be a base station, a transmission reception point (transmit and receive point, TRP), or an access point. The base station may be a base transceiver station (base transceiver station, BTS) in GSM or CDMA, or may be a NodeB (nodeB) in WCDMA, or may be an evolved NodeB (evolved node B, eNB or e-NodeB) in LTE, or may be a gNodeB (gNB) in NR or <NUM>. This is not specifically limited in the embodiments of this application.

The mentioned carrier deployment mode is not specifically limited in the embodiments of this application. In an example, the carrier deployment mode may be a standalone (standalone) deployment mode, and the standalone carrier deployment mode may not depend on another communications system. For example, a carrier deployment bandwidth in the standalone deployment mode may be completely decoupled from a long term evolution (long term evolution, LTE) cell. In another example, the carrier deployment mode may be a guard-band (guardband) deployment mode, and a carrier in the guard-band deployment mode may not occupy a resource of another communications system. For example, the carrier in the guard-band deployment mode may not occupy an LTE resource, and may be deployed on an unused resource block in an LTE edge guard band. In another example, the carrier deployment mode may be an in-band (inband) deployment mode, and a carrier in the in-band deployment mode may be deployed in an operating bandwidth of another communications system. For example, the carrier in the in-band deployment mode may be deployed in an LTE operating bandwidth.

In an FDD scenario, an anchor carrier is a carrier on which the terminal device assumes that a primary synchronization signal (primary synchronization signal, PSS), a secondary synchronization signal (secondary synchronization signal, SSS), a physical broadcast channel (physical broadcast channel, PBCH), or a system information block (system information block, SIB) is transmitted. A non-anchor carrier is a carrier on which the terminal device assumes that no PSS, SSS, PBCH, or SIB is transmitted.

For a TDD scenario, refer to FDD. An anchor carrier may be understood as a carrier used to transmit a PSS, an SSS, and a PBCH, and a non-anchor carrier may be understood as a carrier used to transmitting other information instead of a PSS, an SSS, and a PBCH. A definition of an anchor carrier in the TDD scenario may be slightly different from that in the FDD scenario. Regardless of the TDD scenario or the FDD scenario, types of information that can be transmitted on the anchor carrier are more than those on the non-anchor carrier.

Generally, a subframe for transmitting the PSS is a subframe <NUM>, and the PSS is transmitted in each radio frame. A subframe for transmitting the SSS is a subframe <NUM>, and the SSS is transmitted in an even-numbered radio frame. A subframe for transmitting the PBCH is a subframe <NUM>, and the PBCH is transmitted in each radio frame. On the anchor carrier, a subframe for transmitting a SIB1 is a subframe <NUM> or a subframe <NUM>, and the subframe <NUM> for transmitting the SIB1 is a subframe <NUM> in which no SSS is transmitted.

In a communications system, there are a plurality of types of SIBs, and different SIBs carry different parameters and have different functions.

A SIB1 mainly carries information related to cell access and cell selection, scheduling information of another SIB, and the like, and is a most important system information block. The scheduling information of the another SIB that is carried in the SIB1 includes at least one of a period of system information (system information, SI), a window length of the SI, a window offset of the SI, a repetition mode of the SI, a size of a system information block, and mapping information of the another SIB. The another SIB is a system information block other than the SIB1.

It should be noted that, in an NB-IoT scenario, the SIB1 is a narrowband system information block <NUM> (system information block type1-narrow band, SIB <NUM>-NB), and the another SIB is another SIB-NB.

In the TDD scenario, an LTE communications system currently supports the following uplink-downlink subframe configurations <NUM> to <NUM> shown in Table <NUM>. "D" represents a downlink subframe, and is used for downlink transmission. "U" represents an uplink subframe, and is used for uplink transmission. "S" represents a special subframe, and the special subframe includes a guard period (guard period, GP), an uplink pilot timeslot (uplink pilot time slot, UpPTS), and a downlink pilot timeslot (downlink pilot time slot, DwPTS). UpPTS is used for uplink transmission, and DwPTS is used for downlink transmission. Currently, NB-IoT TDD supports the uplink-downlink subframe configurations <NUM> to <NUM>, and the uplink-downlink subframe configuration <NUM> is under discussion. In the future, NB-IoT TDD may also support the uplink-downlink subframe configuration <NUM>.

In the TDD scenario, because a quantity of downlink subframes in a radio frame is limited, another SIB may be sent on the non-anchor carrier. Specifically, a master information block (master information block, MIB) may indicate whether the SIB1 is sent on the anchor carrier or the non-anchor carrier, and the SIB1 indicates whether another SIB is sent on the anchor carrier or the non-anchor carrier.

When the another SIB is sent on the non-anchor carrier, the terminal device does not know a valid subframe that is on the non-anchor carrier and that is used for transmitting the another SIB. In this case, the terminal device may receive the another SIB in an invalid subframe on the non-anchor carrier. Consequently, the terminal device cannot correctly receive the another SIB, and cannot work normally in the TDD scenario.

The valid subframe mentioned in the embodiments of this application may include a valid downlink subframe, a valid uplink subframe, and/or a valid special subframe.

The valid downlink subframe may be a downlink subframe used for transmitting a physical downlink shared channel (physical downlink shared channel, PDSCH) other than the SIB1. In other words, the terminal device determines that a subframe in which the PDSCH carrying the SIB1 is located is an invalid downlink subframe. The invalid downlink subframe may be a downlink subframe that cannot be used for transmitting the PDSCH.

The valid uplink subframe may be an uplink subframe used for transmitting a physical uplink shared channel (physical uplink shared channel, PUSCH) and/or a physical random access channel (physical random access channel, PRACH). An invalid uplink subframe may be an uplink subframe that cannot be used for transmitting the PUSCH and/or the PRACH.

The valid special subframe may be a special subframe that may be used to transmit related information of the terminal device and/or the network device. An invalid special subframe is a special subframe that cannot be used for transmitting the related information.

For definitions of the valid uplink subframe, the invalid uplink subframe, the valid special subframe, and the invalid special subframe, refer to those in the FDD scenario. The definitions in the TDD scenario may be slightly different.

The embodiments of this application provide a communications method, to determine a valid subframe that is on a non-anchor carrier and that is used for transmitting another SIB, thereby ensuring that a terminal device can work normally in a TDD scenario.

<FIG> is a schematic flowchart of a communications method according to an embodiment of this application. The method in <FIG> may be performed by a terminal device, or may be performed by a chip in the terminal device. The method in <FIG> includes steps <NUM> to <NUM>. The following separately describes steps <NUM> to <NUM> in detail.

Step <NUM>: Determine a valid subframe and an invalid subframe on an anchor carrier.

Step <NUM>: Determine at least one valid subframe on a non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier.

In this embodiment of this application, the at least one valid subframe on the non-anchor carrier may also be referred to as a valid subframe set on the non-anchor carrier. The non-anchor carrier is a carrier used to transmit another SIB. The terminal device may determine a valid subframe and an invalid subframe on the non-anchor carrier based on a valid subframe configuration on the anchor carrier.

Step <NUM>: Receive another SIB in the at least one valid subframe on the non-anchor carrier. In other words, the terminal device receives the another SIB in the valid subframe set on the non-anchor carrier.

In this embodiment of this application, that the terminal device receives the another SIB in the at least one valid subframe on the non-anchor carrier means that the terminal device receives the another SIB in at least one valid downlink subframe, or at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier.

Because the terminal device receives the another SIB in the valid subframe on the non-anchor carrier, it can be ensured that the terminal device correctly receives the another SIB, thereby ensuring that the terminal device can normally work in a TDD scenario. In addition, the terminal device can determine the at least one valid subframe on the non-anchor carrier without introducing new signaling, thereby reducing signaling overheads.

Optionally, the terminal device may determine the valid subframe and the invalid subframe on the anchor carrier based on the valid subframe configuration on the anchor carrier and a subframe for transmitting a first signal on the anchor carrier. The first signal may include at least one of the following signals: a PSS, an SSS, a PBCH, and a SIB1.

Specifically, the terminal device receives a SIB1 sent by a network device. The SIB1 carries preset information, and the preset information is used to indicate the valid subframe configuration on the anchor carrier.

The preset information may be a string of fields or characters. The preset information may be represented by using a bit (bit). For example, the preset information may be represented by using <NUM> bits, or may be represented by using <NUM> bits or <NUM> bits. This is not specifically limited in this embodiment of this application. Specifically, in an in-band deployment mode, <NUM> bits or <NUM> bits may be used to represent the preset information. In a standalone deployment mode or a guard-band deployment mode, <NUM> bits may be used to represent the preset information.

The <NUM> bits correspond to <NUM> subframes in one radio frame, the <NUM> bits correspond to <NUM> subframes in four radio frames, and the <NUM> bits correspond to <NUM> subframes in eight radio frames.

The following describes an indication manner of a valid subframe in this embodiment of this application with reference to <FIG>.

In an example of <NUM> bits, the correspondence may mean that the <NUM>st bit corresponds to a subframe <NUM> in a radio frame X (X mod (<NUM>/<NUM>) = <NUM>) (for example, a radio frame <NUM>), the <NUM>nd bit corresponds to a subframe <NUM> in the radio frame <NUM>, and by analogy, the <NUM>th bit corresponds to a subframe <NUM> in the radio frame <NUM>. When a value of a bit is <NUM>, it indicates that a subframe corresponding to the bit is an invalid subframe. When a value of a bit is <NUM>, it indicates that a subframe corresponding to the bit is a valid subframe.

In an example of <FIG>, assuming that the <NUM> bits are <NUM>, that is, first information is represented by using <NUM>, the first information indicates that the subframe <NUM>, the subframe <NUM>, and the subframe <NUM> are invalid subframes, and the remaining subframes are valid subframes.

In an example of <NUM> bits, the <NUM>st bit corresponds to a subframe <NUM> in a radio frame X (X mod (<NUM>/<NUM>) = <NUM>), the <NUM>nd bit corresponds to a subframe <NUM> in the radio frame X, the <NUM>th bit corresponds to a subframe <NUM> in the radio frame X, the <NUM>th bit corresponds to a subframe <NUM> in a radio frame X+<NUM>, and by analogy, the <NUM>th bit corresponds to a subframe <NUM> in a radio frame X+<NUM>.

In an example of <FIG>, assuming that the <NUM> bits are <NUM><NUM>, it indicates that the subframe <NUM>, the subframe <NUM>, and the subframe <NUM> in the radio frame <NUM> are invalid subframes, the subframe <NUM> in the radio frame <NUM> is an invalid subframe, the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, and the subframe <NUM> in the radio frame <NUM> are invalid subframes, the subframe <NUM> and the subframe <NUM> in the radio frame <NUM> are invalid subframes, and the remaining subframes are valid subframes.

In addition, the terminal device further determines the subframe for transmitting the first signal on the anchor carrier, and determines that the subframe for transmitting the first signal on the anchor carrier is an invalid subframe. For example, if the terminal device determines that a subframe for transmitting the SSS on the anchor carrier is a subframe <NUM>, a subframe for transmitting the PSS on the anchor carrier is a subframe <NUM>, a subframe for transmitting the PBCH on the anchor carrier is a subframe <NUM>, and a subframe for transmitting the SIB <NUM> on the anchor carrier is a subframe <NUM>, the terminal device further determines that the subframe <NUM> for transmitting the SSS, the subframe <NUM>, the subframe <NUM>, and the subframe <NUM> for transmitting the SIB1-NB on the anchor carrier are invalid subframes. In other words, the terminal device finally determines that valid subframes on the anchor carrier are a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and a subframe <NUM>, and invalid subframes on the anchor carrier are the subframe <NUM> for transmitting the SSS, the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, and the subframe <NUM>.

It should be understood that not all periods of the first signal are <NUM>. In other words, the first signal is not necessarily transmitted in each radio frame. The terminal device determines only a corresponding subframe in a radio frame for transmitting the first signal as an invalid subframe on the anchor carrier. In an example of the SSS signal, if the SSS signal is sent in a subframe <NUM> in an even-numbered radio frame, the terminal device determines only the subframe <NUM> in the even-numbered radio frame as an invalid subframe, and still determines, based on the preset information, whether a subframe <NUM> in an odd-numbered radio frame is a valid subframe. If a bit corresponding to the preset information indicates that the subframe <NUM> in the odd-numbered radio frame is a valid subframe, the subframe <NUM> in the radio frame is a valid subframe.

In an example of <FIG>, the terminal device determines that in a radio frame <NUM> on the anchor carrier, invalid subframes are a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and a subframe <NUM>, and valid subframes are a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and a subframe <NUM>. In the radio frame <NUM>, valid downlink subframes are the subframe <NUM> and the subframe <NUM>, and a valid special subframe is the subframe <NUM>. The terminal device determines that in a radio frame <NUM>, invalid subframes are a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and a subframe <NUM>, and valid subframes are a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and a subframe <NUM>. In the radio frame <NUM>, a valid downlink subframe is the subframe <NUM>, and a valid special subframe is the subframe <NUM>.

A specific implementation of step <NUM> is not specifically limited in this embodiment of this application. In an example, the terminal device may determine at least one valid downlink subframe on the non-anchor carrier based on a valid downlink subframe and an invalid downlink subframe on the anchor carrier. The terminal device receives another SIB in the at least one valid downlink subframe on the non-anchor carrier. In another example, the terminal device may determine at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier based on a valid downlink subframe and a valid special subframe on the anchor carrier. The terminal device receives another SIB in the at least one valid downlink subframe and the at least one valid special subframe on the non-anchor carrier. In another example, the terminal device may determine the valid subframe on the non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier. The terminal device determines at least one valid downlink subframe, or at least one valid downlink subframe and at least one special subframe on the non-anchor carrier based on an uplink-downlink subframe configuration on the non-anchor carrier and the at least one valid subframe on the non-anchor carrier, and the terminal device receives another SIB in the at least one valid downlink subframe, or the at least one valid downlink subframe and the at least one special subframe on the non-anchor carrier.

The following describes a specific implementation of step <NUM> in detail by using an example.

In an example, the terminal device may directly determine that a subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier. The correspondence may mean that super frames on the anchor carrier are in a one-to-one correspondence with super frames on the non-anchor carrier, radio frames on the anchor carrier are in a one-to-one correspondence with radio frames on the non-anchor carrier, and subframes on the anchor carrier are in a one-to-one correspondence with subframes on the non-anchor carrier. For example, a radio frame <NUM> on the anchor carrier corresponds to a radio frame <NUM> on the non-anchor carrier, and a radio frame <NUM> on the anchor carrier corresponds to a radio frame <NUM> on the non-anchor carrier; a subframe <NUM> in the radio frame <NUM> on the anchor carrier corresponds to a subframe <NUM> in the radio frame <NUM> on the non-anchor carrier, and a subframe <NUM> in the radio frame <NUM> on the anchor carrier corresponds to a subframe <NUM> in the radio frame <NUM> on the non-anchor carrier.

In an example of a valid subframe and an invalid subframe in the radio frame <NUM> on the anchor carrier, the terminal device determines that at least one valid subframe in the radio frame <NUM> on the non-anchor carrier is a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, a subframe <NUM>, and a subframe <NUM>.

In another example, when a SIB <NUM> is transmitted on the anchor carrier, the terminal device may determine that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier and a subframe that is on the non-anchor carrier and that corresponds to a subframe for transmitting a target signal on the anchor carrier are the at least one valid subframe on the non-anchor carrier. The target signal includes at least one of the following signals: a PSS, an SSS, a PBCH, and a SIB1.

The subframe that is on the non-anchor carrier and that corresponds to the subframe for transmitting the target signal on the anchor carrier may mean that a subframe <NUM> for transmitting the PSS on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, a subframe <NUM> for transmitting the SSS on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, a subframe <NUM> for transmitting the PBCH on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, a subframe <NUM> for transmitting the SIB <NUM> on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, or a subframe <NUM> for transmitting the SIB <NUM> on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier.

In an example of <FIG>, if the terminal device determines that a subframe for transmitting the SSS on the anchor carrier is the subframe <NUM>, a subframe for transmitting the PSS on the anchor carrier is the subframe <NUM>, a subframe for transmitting the PBCH on the anchor carrier is the subframe <NUM>, and a subframe for transmitting the SIB <NUM> on the anchor carrier is the subframe <NUM>, the terminal device determines that at least one valid subframe in the radio frame <NUM> on the non-anchor carrier is the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, and the subframe <NUM>. The terminal device determines that in the radio frame <NUM>, valid downlink subframes on the non-anchor carrier are the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, the subframe <NUM>, and the subframe <NUM>, and a valid special subframe is the subframe <NUM>.

Optionally, in an embodiment, if the terminal device determines that the SIB1 is transmitted on a non-anchor carrier, and the non-anchor carrier on which the SIB <NUM> is transmitted and a non-anchor carrier on which another SIB is transmitted are a same non-anchor carrier, the terminal device may determine that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier, and determine that the subframe that is on the non-anchor carrier and that is used for transmitting the SIB1 is an invalid subframe.

Further, the terminal device may determine that subframes that are on the non-anchor carrier and that correspond to the subframes for transmitting the PSS, the SSS, and the PBCH on the anchor carrier are valid subframes on the non-anchor carrier.

It should be noted that, in an NB-IoT scenario, the PSS is a narrowband primary synchronization signal (narrow band primary synchronization signal, NPSS), the SSS is a narrowband secondary synchronization signal (narrow band secondary synchronization signal, NSSS), the PBCH is a narrowband physical broadcast channel (narrow band physical broadcast channel, NPBCH), and the SIB1 is a SIB1-NB.

<FIG> is a schematic flowchart of another communications method according to an embodiment of this application in accordance with the claims. The method in <FIG> includes steps <NUM> to <NUM>. The following describes steps <NUM> to <NUM> in detail.

Step <NUM>: Receive a SIB1, where the SIB1 includes first information, and the first information is used to indicate a valid subframe configuration on a non-anchor carrier.

The first information may be a string of fields or characters. The first information may be represented by using a bit. For example, the first information occupies M bits, and M is a positive integer. The M bits may be <NUM> bits, or may be <NUM> bits or <NUM> bits. This is not specifically limited in this embodiment of this application. Specifically, in an in-band deployment mode, <NUM> bits or <NUM> bits may be used to represent the preset information. In a standalone deployment mode or a guard-band deployment mode, <NUM> bits may be used to represent the first information.

Each bit in the M bits is used to indicate whether a subframe corresponding to the bit is a valid subframe or an invalid subframe on the non-anchor carrier. The correspondence may mean that each bit in the M bits is in a one-to-one correspondence with each subframe on the non-anchor carrier. The <NUM> bits correspond to <NUM> subframes in one radio frame, the <NUM> bits correspond to <NUM> subframes in four radio frames, and the <NUM> bits correspond to <NUM> subframes in eight radio frames.

In an example in which the M bits are <NUM> bits, the correspondence means that the <NUM>st bit corresponds to a subframe <NUM> in a radio frame <NUM>, the <NUM>nd bit corresponds to a subframe <NUM> in the radio frame <NUM>, and by analogy, the <NUM>th bit corresponds to a subframe <NUM> in the radio frame <NUM>. When a value of a bit is <NUM>, it indicates that a subframe corresponding to the bit is an invalid subframe. When a value of a bit is <NUM>, it indicates that a subframe corresponding to the bit is a valid subframe.

Step <NUM>: Determine at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the non-anchor carrier.

In this embodiment of this application, the at least one valid subframe on the non-anchor carrier may also be referred to as a valid subframe set on the non-anchor carrier. The non-anchor carrier is a carrier used to transmit another SIB. A terminal device may determine a valid subframe and an invalid subframe on the non-anchor carrier based on the valid subframe configuration on the non-anchor carrier.

Step <NUM>: Receive another SIB in the at least one valid subframe on the non-anchor carrier.

In this embodiment of this application, because the terminal device receives the another SIB in the valid subframe on the non-anchor carrier, it can be ensured that the terminal device correctly receives the another SIB, thereby ensuring that the terminal device can normally work in a TDD scenario.

Optionally, in an embodiment, the first information may also be used to indicate a valid subframe configuration on an anchor carrier. In other words, in this embodiment of this application, the first information may be reused, and the first information is used to indicate both the valid subframe configuration on the anchor carrier and the valid subframe configuration on the non-anchor carrier. In this way, signaling overheads can be reduced.

In an embodiment in accordance with the claims, the SIB1 further includes second information, and the second information is used to indicate the valid subframe configuration on the anchor carrier. In other words, the first information is information newly added to the SIB1, and the first information is specially used to indicate the valid subframe configuration on the non-anchor carrier. In this indication manner, a valid subframe and an invalid subframe on the non-anchor carrier can be accurately indicated, so as to avoid a resource waste.

In addition, an embodiment of this application further provides a communications method. A terminal device receives a SIB1, where the SIB1 includes third information and fourth information, the third information is used to indicate a valid subframe configuration on an anchor carrier, and the fourth information is used to indicate a valid subframe configuration of a subframe that is on a non-anchor carrier and that corresponds to an invalid subframe on the anchor carrier. The terminal device determines at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the anchor carrier and the valid subframe configuration of the subframe that is on the non-anchor carrier and that corresponds to the invalid subframe on the anchor carrier, and receives another SIB in the at least one valid subframe on the non-anchor carrier.

Specifically, after receiving the valid subframe configuration on the anchor carrier, the terminal device may determine a valid subframe and an invalid subframe on the anchor carrier according to the foregoing method. The terminal device may determine that a subframe that is on the non-anchor carrier and that corresponds to a valid subframe on the anchor carrier is a valid subframe, and determine, based on the fourth information, whether the remaining subframes on the non-anchor carrier are valid subframes or invalid subframes.

The fourth information may be a string of fields or characters. The fourth information may be represented by using a bit. When a value of a bit is <NUM>, it indicates that a subframe corresponding to the bit is a valid subframe. When a value of a bit is <NUM>, it indicates that a subframe corresponding to the bit is an invalid subframe.

According to the technical solution provided in this embodiment of this application, only less information is required to indicate whether the subframe that is on the non-anchor carrier and that corresponds to the invalid subframe on the anchor carrier is a valid subframe or an invalid subframe. Therefore, a valid subframe and an invalid subframe on the non-anchor carrier can be accurately determined with relatively low signaling overheads.

<FIG> is a schematic flowchart of another communications method according to an embodiment of this application. The method in <FIG> may be performed by a network device, or may be performed by a chip in the network device. The method in <FIG> includes steps <NUM> to <NUM>. The following describes steps <NUM> to <NUM> in detail.

In this embodiment of this application, the at least one valid subframe on the non-anchor carrier may also be referred to as a valid subframe set on the non-anchor carrier. The non-anchor carrier is a carrier used to transmit another SIB. The network device may determine a valid subframe and an invalid subframe on the non-anchor carrier based on a valid subframe configuration on the anchor carrier.

Step <NUM>: Send another SIB in the at least one valid subframe on the non-anchor carrier. In other words, the terminal device sends the another SIB in the valid subframe set on the non-anchor carrier.

In this embodiment of this application, that the network device sends the another SIB in at the least one valid subframe on the non-anchor carrier means that the network device sends the another SIB in at least one valid downlink subframe, or at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier.

The network device determines the at least one valid subframe on the non-anchor carrier in a specific manner, and sends the another SIB in the at least one valid subframe on the non-anchor carrier, so as to ensure that the terminal device correctly receives the another SIB, thereby ensuring normal communication with a terminal device. In addition, the network device can determine the at least one valid subframe on the non-anchor carrier without introducing new signaling, thereby reducing signaling overheads.

Optionally, the network device may determine the valid subframe and the invalid subframe on the anchor carrier based on the valid subframe configuration on the anchor carrier and a subframe for transmitting a first signal on the anchor carrier. The first signal includes at least one of the following signals: a PSS, an SSS, a PBCH, and a SIB1.

Specifically, when the network device sends a SIB1, the SIB1 carries preset information, and the preset information is used to indicate the valid subframe configuration on the anchor carrier.

The <NUM> bits correspond to <NUM> subframes in one radio frame, the <NUM> bits correspond to <NUM> subframes in four radio frames, and the <NUM> bits correspond to <NUM> subframes in eight radio frames. In an example of <NUM> bits, the correspondence may mean that the <NUM>st bit corresponds to a subframe <NUM> in a radio frame <NUM>, the <NUM>nd bit corresponds to a subframe <NUM> in the radio frame <NUM>, and by analogy, the <NUM>th bit corresponds to a subframe <NUM> in the radio frame <NUM>. When a value of a bit is <NUM>, it indicates that a subframe corresponding to the bit is an invalid subframe. When a value of a bit is <NUM>, it indicates that a subframe corresponding to the bit is a valid subframe.

After determining the valid subframe and the invalid subframe on the anchor carrier based on the preset information, the network device further determines the subframe for transmitting the first signal on the anchor carrier, and determines that the subframe for transmitting the first signal on the anchor carrier is an invalid subframe. For a specific manner of determining the valid subframe and the invalid subframe on the anchor carrier, refer to the foregoing description. For brevity, details are not described herein again.

A specific implementation of step <NUM> is not specifically limited in this embodiment of this application. In an example, the network device may determine at least one valid downlink subframe on the non-anchor carrier based on a valid downlink subframe and an invalid downlink subframe on the anchor carrier. The network device sends another SIB in the at least one valid downlink subframe on the non-anchor carrier. In another example, the network device may determine at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier based on a valid downlink subframe and a valid special subframe on the anchor carrier. The network device sends another SIB in the at least one valid downlink subframe and the at least one valid special subframe on the non-anchor carrier. In another example, the network device may determine the valid subframe on the non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier. The network device determines at least one valid downlink subframe, or at least one valid downlink subframe and at least one special subframe on the non-anchor carrier based on an uplink-downlink subframe configuration on the non-anchor carrier and at least one valid subframe on the non-anchor carrier, and the network device sends another SIB in the at least one valid downlink subframe, or the at least one valid downlink subframe and the at least one special subframe on the non-anchor carrier.

The following describes a specific implementation manner of step <NUM> in detail by using an example.

In an example, the network device may directly determine that a subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier. The correspondence may mean that super frames on the anchor carrier are in a one-to-one correspondence with super frames on the non-anchor carrier, radio frames on the anchor carrier are in a one-to-one correspondence with radio frames on the non-anchor carrier, and subframes on the anchor carrier are in a one-to-one correspondence with subframes on the non-anchor carrier. For example, a radio frame <NUM> on the anchor carrier corresponds to a radio frame <NUM> on the non-anchor carrier, and a radio frame <NUM> on the anchor carrier corresponds to a radio frame <NUM> on the non-anchor carrier; a subframe <NUM> on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier, and a subframe <NUM> on the anchor carrier corresponds to a subframe <NUM> on the non-anchor carrier.

In another example, when a SIB <NUM> is transmitted on the anchor carrier, the network device may determine that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier and a subframe corresponding to a subframe for transmitting a target signal on the anchor carrier are the at least one subframe on the non-anchor carrier. The target signal includes at least one of the following signals: a PSS, an SSS, a PBCH, and a SIB1.

Optionally, in an embodiment, if the network device determines that the SIB1 is transmitted on a non-anchor carrier, and the non-anchor carrier on which the SIB <NUM> is transmitted and a non-anchor carrier on which another SIB is transmitted are a same non-anchor carrier, the network device may determine that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier, and determine that a subframe that is on the non-anchor carrier and that is used for transmitting the SIB1 is an invalid subframe.

Further, the network device may determine that subframes that are on the non-anchor carrier and that correspond to the subframes for transmitting the PSS, the SSS, and the PBCH on the anchor carrier are valid subframes.

It should be noted that, in an NB-IoT scenario, the PSS is an NPSS, the SSS is an NSSS, the PBCH is an NPBCH, and the SIB1 is a SIB1-NB.

<FIG> is a schematic flowchart of another communications method according to an embodiment of this application in accordance with the claims. The method in <FIG> may be performed by a network device, or may be performed by a chip in the network device. The method in <FIG> includes steps <NUM> to <NUM>. The following describes steps <NUM> to <NUM> in detail.

Step <NUM>: Send a SIB1, where the SIB1 includes first information, and the first information is used to indicate a valid subframe configuration on a non-anchor carrier.

The first information may be a string of fields or characters. The first information may be represented by using a bit. For example, the first information occupies M bits, and M is a positive integer. The M bits may be <NUM> bits, or may be <NUM> bits or <NUM> bits. This is not specifically limited in this embodiment of this application.

In this embodiment of this application, the at least one valid subframe on the non-anchor carrier may also be referred to as a valid subframe set on the non-anchor carrier. The non-anchor carrier is a carrier used to transmit another SIB. The network device may determine a valid subframe and an invalid subframe on the non-anchor carrier based on the valid subframe configuration on the non-anchor carrier.

Step <NUM>: Send another SIB in the at least one valid subframe on the non-anchor carrier.

The network device determines the at least one valid subframe on the non-anchor carrier in a specific manner, and sends the another SIB in the at least one valid subframe on the non-anchor carrier, so as to ensure that the terminal device correctly receives the another SIB, thereby ensuring normal communication with a terminal device.

In addition, an embodiment of this application further provides a communications method. A network device sends a SIB1, where the SIB1 includes third information and fourth information, the third information is used to indicate a valid subframe configuration on an anchor carrier, and the fourth information is used to indicate a valid subframe configuration of a subframe that is on a non-anchor carrier and that corresponds to an invalid subframe on the anchor carrier. The network device determines at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the anchor carrier and the valid subframe configuration of the subframe that is on the non-anchor carrier and that corresponds to the invalid subframe on the anchor carrier, and sends another SIB in the at least one valid subframe on the non-anchor carrier.

<FIG> is a schematic block diagram of a communications apparatus according to an embodiment of this application. The communications apparatus may be a terminal device, or may be a chip or another component in the terminal device. The communications apparatus includes a determining unit <NUM> and a receiving unit <NUM>.

The determining unit <NUM> is configured to determine a valid subframe and an invalid subframe on an anchor carrier.

The determining unit <NUM> is further configured to determine at least one valid subframe on a non-anchor carrier based on the valid subframe and the invalid subframe on the anchor carrier.

The receiving unit <NUM> is configured to receive another system information block SIB in the at least one valid subframe on the non-anchor carrier.

Optionally, the terminal device may determine the valid subframe and the invalid subframe on the anchor carrier based on the valid subframe configuration on the anchor carrier and a subframe for transmitting a first signal on the anchor carrier. The first signal includes at least one of the following signals: a PSS, an SSS, a PBCH, and a SIB1.

A manner in which the terminal device determines the at least one valid subframe on the non-anchor carrier is not specifically limited in this embodiment of this application. In an example, the terminal device may directly determine that a subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier. In another example, when a SIB <NUM> is transmitted on the anchor carrier, the terminal device may determine that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier and a subframe corresponding to a subframe for transmitting a target signal on the anchor carrier are the at least one valid subframe on the non-anchor carrier. The target signal includes at least one of the following signals: a PSS, an SSS, a PBCH, and a SIB1.

Optionally, in an embodiment, if the terminal device determines that the SIB1 is transmitted on a non-anchor carrier, and the non-anchor carrier on which the SIB <NUM> is transmitted and a non-anchor carrier on which another SIB is transmitted are a same non-anchor carrier, the terminal device may determine that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier, and determine that a subframe that is on the non-anchor carrier and that is used for transmitting the SIB1 is an invalid subframe.

<FIG> is a schematic block diagram of another communications apparatus according to an embodiment of this application. The communications apparatus may be a terminal device, or may be a chip or another component in the terminal device. The communications apparatus includes a receiving unit <NUM> and a determining unit <NUM>.

The receiving unit <NUM> is configured to receive a system information block SIB1, where the SIB1 includes first information, and the first information is used to indicate a valid subframe configuration on a non-anchor carrier.

The determining unit <NUM> is configured to determine at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the non-anchor carrier.

In this embodiment of this application, the at least one valid subframe on the non-anchor carrier may also be referred to as a valid subframe set on the non-anchor carrier. The non-anchor carrier is a carrier used to transmit another SIB. The terminal device may determine a valid subframe and an invalid subframe on the non-anchor carrier based on the valid subframe configuration on the non-anchor carrier.

The receiving unit <NUM> is further configured to receive another system information block SIB in the at least one valid subframe on the non-anchor carrier.

In this embodiment of this application, because the terminal device receives the another SIB in the at least one valid subframe on the non-anchor carrier, it can be ensured that the terminal device correctly receives the another SIB, thereby ensuring that the terminal device can normally work in a TDD scenario.

Optionally, in an embodiment, the SIB1 further includes second information, and the second information is used to indicate the valid subframe configuration on the anchor carrier. In other words, the first information is information newly added to the SIB1, and the first information is specially used to indicate the valid subframe configuration on the non-anchor carrier. In this indication manner, a valid subframe and an invalid subframe on the non-anchor carrier can be accurately indicated, so as to avoid a resource waste.

In addition, an embodiment of this application further provides a communications apparatus. A terminal device receives a SIB1, where the SIB1 includes third information and fourth information, the third information is used to indicate a valid subframe configuration on an anchor carrier, and the fourth information is used to indicate a valid subframe configuration of a subframe that is on a non-anchor carrier and that corresponds to an invalid subframe on the anchor carrier. The terminal device determines at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the anchor carrier and the valid subframe configuration of the subframe that is on the non-anchor carrier and that corresponds to the invalid subframe on the anchor carrier, and receives another SIB in the at least one valid subframe on the non-anchor carrier.

As shown in <FIG>, an embodiment of this application further provides a communications apparatus <NUM>. The communications apparatus <NUM> includes a processor <NUM>, a memory <NUM>, and a transceiver <NUM>. The memory <NUM> is configured to store an instruction, and the processor <NUM> and the transceiver <NUM> are configured to execute the instruction stored in the memory <NUM>. The communications apparatus <NUM> may be a terminal device or a component in the terminal device, for example, a chip or a chip set.

It should be understood that the communications apparatus <NUM> shown in <FIG> or the communications apparatus <NUM> shown in <FIG> may be configured to perform operations or procedures in the foregoing method embodiments, and operations and/or functions of the units in the communications apparatus <NUM> or the communications apparatus <NUM> are respectively intended to implement corresponding procedures in the foregoing method embodiments. For brevity, details are not described herein again.

<FIG> is a schematic block diagram of another communications apparatus according to an embodiment of this application. The communications apparatus may be a network device, or may be a chip or another component in the network device. The communications apparatus includes a determining unit <NUM> and a sending unit <NUM>.

The sending unit <NUM> is configured to send another system information block SIB in the at least one valid subframe on the non-anchor carrier.

In this embodiment of this application, that the network device sends the another SIB in the at least one valid subframe on the non-anchor carrier means that the network device sends the another SIB in at least one valid downlink subframe, or at least one valid downlink subframe and at least one valid special subframe on the non-anchor carrier.

The network device can send the another SIB in the at least one valid subframe on the non-anchor carrier, so as to ensure normal communication with a terminal device. In addition, the network device can determine the at least one valid subframe on the non-anchor carrier without introducing new signaling, thereby reducing signaling overheads.

A manner in which the network device determines the at least one valid subframe on the non-anchor carrier is not specifically limited in this embodiment of this application. In an example, the network device may directly determine that a subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier is the at least one valid subframe on the non-anchor carrier. In another example, when a SIB <NUM> is transmitted on the anchor carrier, the network device may determine that the subframe that is on the non-anchor carrier and that corresponds to the valid subframe on the anchor carrier and a subframe corresponding to a subframe for transmitting a target signal on the anchor carrier are the at least one valid subframe on the non-anchor carrier. The target signal includes at least one of the following signals: a PSS, an SSS, a PBCH, and a SIB1.

Further, the network device may determine that subframes that are on the non-anchor carrier and that correspond to the subframes for transmitting the PSS, the SSS, and the PBCH on the anchor carrier are valid subframes on the non-anchor carrier.

It should be noted that, in an NB-IoT scenario, the PSS is an NPSS, the SSS is an NSSS, the PBCH is an NPBCH, and the SIB <NUM> is a SIB <NUM>-NB.

<FIG> is a schematic block diagram of another communications apparatus according to an embodiment of this application. The communications apparatus may be a network device, or may be a chip or another component in the network device. The communications apparatus includes a sending unit <NUM> and a determining unit <NUM>.

The sending unit <NUM> is configured to send a system information block SIB1, where the SIB1 includes first information, and the first information is used to indicate a valid subframe configuration on a non-anchor carrier.

The sending unit <NUM> is further configured to send another system information block SIB in the at least one valid subframe on the non-anchor carrier.

The network device can send the another SIB in the at least one valid subframe on the non-anchor carrier, so as to ensure normal communication with a terminal device.

In addition, an embodiment of this application further provides a communications apparatus. A network device sends a SIB1, where the SIB1 includes third information and fourth information, the third information is used to indicate a valid subframe configuration on an anchor carrier, and the fourth information is used to indicate a valid subframe configuration of a subframe that is on a non-anchor carrier and that corresponds to an invalid subframe on the anchor carrier. The network device determines at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the anchor carrier and the valid subframe configuration of the subframe that is on the non-anchor carrier and that corresponds to the invalid subframe on the anchor carrier, and receives another SIB in the at least one valid subframe on the non-anchor carrier.

As shown in <FIG>, an embodiment of this application further provides a communications apparatus <NUM>. The communications apparatus <NUM> includes a processor <NUM>, a memory <NUM>, and a transceiver <NUM>. The memory <NUM> is configured to store an instruction, and the processor <NUM> and the transceiver <NUM> are configured to execute the instruction stored in the memory <NUM>. The communications apparatus <NUM> may be a network device or a component in the network device, for example, a chip or a chip set.

In any one of <FIG>, <FIG>, <FIG>, and <FIG>, the transceiver is specifically configured to receive and send a signal, and the processor is configured to control the transceiver to receive and send the signal, and perform another processing or determining function. Therefore, the transceiver is equivalent to an execution body for receiving and sending an air interface signal, and the processor is a controller for receiving and sending the air interface signal, and is configured to schedule or control the transceiver to implement receiving and sending. The processor is driven by an instruction in the memory to control the transceiver to work, to implement receiving and sending of various signals, and jointly implement a procedure of any one of the foregoing method embodiments.

Persons of ordinary skill in the art may be aware that, in combination with the examples described in the embodiments disclosed in this specification, units and algorithm steps may be implemented by electronic hardware or a combination of computer software and electronic hardware. Persons skilled in the art may use different methods to implement the described functions for each particular application, but it should not be considered that the implementation goes beyond the scope of this application.

For example, the division into units is merely division into logical functions and may be other division in an actual implementation.

The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, may be located in one position, or may be distributed on a plurality of network units.

When the functions are implemented in the form of a software function unit and sold or used as an independent product, the functions may be stored in a computer-readable storage medium. Based on such an understanding, the technical solutions of this application essentially, or the part contributing to the prior art, or some of the technical solutions may be implemented in a form of a software product. The computer software product is stored in a storage medium, and includes several instructions for instructing a computer device (which may be a personal computer, a server, a network device, or the like) to perform all or some of the steps of the methods described in the embodiments of this application. The foregoing storage medium includes: any medium that can store program code, such as a USB flash drive, a removable hard disk, a read-only memory (Read-Only Memory, ROM), a random access memory (Random Access Memory, RAM), a magnetic disk, or an optical disc.

Claim 1:
A communications method performed by a terminal device or a chip in the terminal device, the method comprising the steps of:
• receiving (step <NUM>) a system information block SIB1, wherein the SIB1 comprises scheduling information of another SIB, first information and second information,
wherein the another SIB is a system information block other than the SIB1; the scheduling information of another SIB comprises at least one of a period of system information SI, a window length of the SI, a window offset of the SI, a repetition mode of the SI, a size of a system information block, and mapping information of the another SIB; the first information is used to indicate a valid subframe configuration on a non-anchor carrier; the second information is used to indicate a valid subframe configuration on an anchor carrier; and the SIB1 indicates that the another SIB is sent on the non-anchor carrier;
• determining (step <NUM>) at least one valid subframe on the non-anchor carrier based on the valid subframe configuration on the non-anchor carrier; and
• receiving (step <NUM>) the another SIB in the at least one valid subframe on the non-anchor carrier.