CN109673057B - Random access method and device under asymmetric uplink carrier aggregation - Google Patents

Background

In the existing Long Term Evolution (LTE) system, a single carrier supports a system bandwidth of 20M at maximum, and if a larger bandwidth is required, a carrier aggregation technique needs to be adopted. In a private network, there are a large number of applications such as video monitoring services, and the like, and the service demand of this type of service is greater for uplink than for downlink.

The prior art provides an asymmetric uplink carrier aggregation method, which can satisfy a scenario that the uplink service demand is greater than the downlink service demand. In the method, for example, there are N downlink carriers and M uplink carriers, where N is less than or equal to M, and the existing processing procedure of asymmetric uplink carrier aggregation is as follows: firstly, a base station decomposes N downlink carriers and M uplink carriers into a plurality of carrier aggregation clusters, where each carrier aggregation cluster includes one downlink carrier and K uplink carriers, K is an integer greater than or equal to 1, fig. 1 is a schematic diagram of a main carrier and an auxiliary carrier, as shown in fig. 1, one uplink carrier corresponding to a downlink carrier and the downlink carrier constitute the main carrier, and the remaining K-1 uplink carriers are the auxiliary carriers. And then the base station carries out carrier aggregation on the decomposed multiple carrier aggregation clusters.

In the above-mentioned existing asymmetric uplink carrier aggregation scenario, since the uplink secondary carrier does not have a corresponding downlink secondary carrier, in this scenario, how to perform random access on the uplink secondary carrier is a problem to be solved.

Disclosure of Invention

The invention provides a random access method and a random access device under asymmetric uplink carrier aggregation, which are used for solving the problem of random access under an asymmetric uplink carrier aggregation scene.

In a first aspect, the present invention provides a random access method under asymmetric uplink carrier aggregation, including:

user Equipment (UE) sends a random access preamble to a base station on an uplink main carrier, and the base station is used for sending a random access response to the UE through a downlink main carrier according to the random access preamble;

the UE receives a random access response sent by the base station;

and the UE sends first scheduling uplink transmission on the uplink main carrier according to the random access response.

Further, after the UE sends the first scheduled uplink transmission on the uplink primary carrier according to the random access response, the method further includes:

the UE receives a Radio Resource Control (RRC) signaling or downlink control information (DCI 0) on a Physical Downlink Control Channel (PDCCH) sent by the base station, wherein the DCI0 or the RRC signaling carries an identifier of an uplink auxiliary carrier;

and the UE sends data on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier.

Further, after the UE sends the first scheduled uplink transmission on the uplink primary carrier according to the random access response, the method further includes:

the UE sends an auxiliary carrier access capability indication message of the UE to the base station, so that the base station sends an RRC reconfiguration message to the UE after acquiring the auxiliary carrier access capability of the UE, wherein the RRC reconfiguration message carries an identifier of at least one uplink auxiliary carrier, and the RRC reconfiguration message is used for indicating the UE to initiate random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message;

and the UE initiates random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

Further, the UE initiates random access on the uplink secondary carrier corresponding to the identifier of the uplink secondary carrier carried in the RRC reconfiguration message, including:

the UE sends a random access preamble to the base station on an uplink auxiliary carrier, where the random access preamble is used for the base station to send a random access response to the UE through the downlink main carrier, and the uplink auxiliary carrier is an uplink auxiliary carrier corresponding to an identifier of any uplink auxiliary carrier carried in the RRC reconfiguration message;

the UE receives a random access response sent by the base station;

and the UE sends first scheduling uplink transmission on the uplink auxiliary carrier according to the random access response.

Further, after the UE sends the first scheduled uplink transmission on the uplink secondary carrier according to the random access response, the method further includes:

and the UE receives a competition resolving message sent to the UE by the base station through the downlink main carrier.

In a second aspect, the present invention provides a random access method under asymmetric uplink carrier aggregation, including:

a base station receives a random access preamble sent by User Equipment (UE) on an uplink main carrier;

the base station sends a random access response to the UE through a downlink main carrier according to the random access preamble, and the random access response is used for sending first-time scheduling uplink transmission on the uplink main carrier by the UE according to the random access response;

and the base station receives the first scheduling uplink transmission sent by the UE on the uplink main carrier.

Further, after the base station receives the first scheduled uplink transmission sent by the UE on the uplink primary carrier, the method further includes:

the base station sends a Radio Resource Control (RRC) signaling or downlink control information (DCI 0) on a Physical Downlink Control Channel (PDCCH) to the UE, wherein the DCI0 or the RRC signaling carries an identifier of an uplink auxiliary carrier and is used for the UE to send data on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier;

and the base station receives data sent by the UE on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier.

Further, after the base station receives the first scheduled uplink transmission sent by the UE on the uplink primary carrier, the method further includes:

the base station receives an auxiliary carrier access capability indication message sent by the UE;

after acquiring the auxiliary carrier access capability of the UE, the base station sends an RRC reconfiguration message to the UE, wherein the RRC reconfiguration message carries an identifier of at least one uplink auxiliary carrier, and the RRC reconfiguration message is used for indicating the UE to initiate random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message;

and the base station receives the random access initiated by the UE on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

Further, the receiving, by the base station, the random access initiated by the UE on the uplink secondary carrier includes:

the base station receives a random access preamble sent by the UE on an uplink auxiliary carrier, wherein the uplink auxiliary carrier is an uplink auxiliary carrier corresponding to an identifier of any uplink auxiliary carrier carried in the RRC reconfiguration message;

and the base station sends a random access response to the UE through the downlink main carrier, and the random access response is used for sending first-time scheduling uplink transmission on the uplink auxiliary carrier by the UE according to the random access response.

Further, still include:

and the base station sends a competition resolving message to the UE through the downlink main carrier.

In a third aspect, the present invention provides a user equipment, comprising:

a sending module, configured to send a random access preamble to a base station on an uplink primary carrier, where the base station sends a random access response to the UE through a downlink primary carrier according to the random access preamble;

a receiving module, configured to receive a random access response sent by the base station;

the sending module is further configured to send a first scheduled uplink transmission on the uplink primary carrier according to the random access response.

Further, the receiving module is further configured to: after the sending module sends the first-time scheduling uplink transmission on the uplink main carrier according to the random access response, receiving a Radio Resource Control (RRC) signaling or downlink control information (DCI 0) on a Physical Downlink Control Channel (PDCCH) sent by the base station, wherein the DCI0 or the RRC signaling carries an identifier of an uplink auxiliary carrier;

the sending module is further configured to: and sending data on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier.

Further, the sending module is further configured to:

after sending the first-time scheduling uplink transmission on the uplink main carrier according to the random access response, sending an auxiliary carrier access capability indication message of the UE to the base station, so that the base station sends an RRC reconfiguration message to the UE after learning the auxiliary carrier access capability of the UE, where the RRC reconfiguration message carries an identifier of at least one uplink auxiliary carrier, and the RRC reconfiguration message is used to indicate the UE to initiate random access on an uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message;

the sending module is further configured to: and initiating random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

Further, the sending module initiates random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message, including:

the sending module sends a random access preamble to the base station on an uplink auxiliary carrier, so that the base station sends a random access response to the UE through the downlink main carrier, where the uplink auxiliary carrier is an uplink auxiliary carrier corresponding to an identifier of any uplink auxiliary carrier carried in the RRC reconfiguration message;

the receiving module is further configured to: receiving a random access response sent by the base station;

and the sending module sends the first scheduling uplink transmission on the uplink auxiliary carrier according to the random access response.

Further, the receiving module is further configured to: and after the sending module sends the first-time scheduling uplink transmission on the uplink auxiliary carrier according to the random access response, receiving a contention resolution message sent by the base station to the UE through the downlink main carrier.

In a fourth aspect, the present invention provides a base station, comprising:

a receiving module, configured to receive a random access preamble sent by a UE on an uplink primary carrier;

a sending module, configured to send a random access response to the UE through a downlink main carrier according to the random access preamble, and to send a first-time scheduling uplink transmission on the uplink main carrier according to the random access response by the UE;

the receiving module is further configured to: and receiving the first scheduling uplink transmission sent by the UE on the uplink main carrier.

Further, the sending module is further configured to:

after the receiving module receives the first scheduling uplink transmission sent by the UE on the uplink main carrier, sending a Radio Resource Control (RRC) signaling or downlink control information (DCI 0) on a Physical Downlink Control Channel (PDCCH) to the UE, wherein the DCI0 or the RRC signaling carries an identifier of an uplink auxiliary carrier and is used for the UE to send data on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier;

the receiving module is further configured to: and receiving data sent by the UE on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier.

Further, the receiving module is further configured to: after receiving the first scheduling uplink transmission sent by the UE on the uplink main carrier, receiving an auxiliary carrier access capability indication message sent by the UE;

the sending module is further configured to: after acquiring the auxiliary carrier access capability of the UE, sending an RRC reconfiguration message to the UE, wherein the RRC reconfiguration message carries an identifier of at least one uplink auxiliary carrier, and the RRC reconfiguration message is used for indicating the UE to initiate random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message;

the receiving module is further configured to: and receiving the random access initiated by the UE on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

Further, the receiving module receives a random access initiated by the UE on an uplink secondary carrier, including:

receiving a random access preamble sent by the UE on an uplink auxiliary carrier, where the uplink auxiliary carrier is an uplink auxiliary carrier corresponding to an identifier of any uplink auxiliary carrier carried in the RRC reconfiguration message;

the sending module is further configured to: and sending a random access response to the UE through the downlink main carrier, wherein the random access response is used for sending first-time scheduling uplink transmission on the uplink auxiliary carrier by the UE according to the random access response.

Further, the sending module is further configured to:

and sending a contention resolution message to the UE through the downlink main carrier.

The random access method and the random access device under the asymmetric uplink carrier aggregation solve the random access problem under the asymmetric uplink carrier aggregation scene by setting the random access to be only carried out on the main carrier.

Detailed Description

In order to make the objects, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings, and it is obvious that the described embodiments are some, but not all embodiments of the present invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

The random access method and device under asymmetric uplink carrier aggregation provided by the invention are used for solving the random access problem under an asymmetric uplink carrier aggregation scene, and as shown in fig. 1, there are an uplink main carrier and a downlink main carrier, and K-1 uplink auxiliary carriers, and the uplink auxiliary carriers do not have corresponding downlink auxiliary carriers.

Fig. 2 is a flowchart of a first embodiment of a random access method under asymmetric uplink carrier aggregation according to the present invention, where this embodiment takes a User Equipment (UE) as an execution subject for description, and as shown in fig. 2, the method of this embodiment may include:

s101, the UE sends a random access preamble to the base station on the uplink main carrier, and the random access preamble is used for sending a random access response to the UE through the downlink main carrier by the base station according to the random access preamble.

Specifically, the UE sends a Random Access preamble to the base station on a Physical Random Access Channel (PRACH) configured on the uplink primary carrier. After receiving the random access preamble, the base station calculates the timing advance by using the random access preamble sequence, allocates channel resources and a Temporary Cell Radio Network Temporary Identifier (Temporary Cell Radio Network Temporary Identifier, referred to as "Temporary C-RNTI") to the UE, and transmits the random access preamble through a physical downlink shared channel of a downlink main carrier, which is called as a random access response.

S102, the UE receives a random access response sent by the base station.

S103, the UE sends first scheduling uplink transmission on the uplink main carrier according to the random access response.

Specifically, the UE sends the first scheduled uplink transmission on the physical uplink shared channel of the uplink primary carrier according to the channel resource allocation information in the random access response.

Since the uplink secondary carrier does not have a corresponding downlink secondary carrier, in the present invention, it is specified that random access is initiated only at the primary carrier. The invention provides two random access methods:

firstly, random access is initiated only in a main carrier, and an auxiliary carrier is not provided with physical random access channel PRACH resources.

After S101-S103, after S103, the method further includes:

the UE receives a Radio Resource Control (RRC) signaling or Downlink Control Information (DCI) 0 on a Physical Downlink Control Channel (PDCCH), where the DCI0 or the RRC signaling carries an identifier of an uplink secondary carrier.

And the UE sends data on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier.

In the random access method under asymmetric uplink carrier aggregation provided by this embodiment, random access is only performed on the primary carrier, and the secondary carrier is used to send data, so that the random access problem under an asymmetric uplink carrier aggregation scenario is solved.

And secondly, the main carrier and the auxiliary carrier independently perform random access, the random access process of the main carrier is the same as the conventional random access process, the random access process of the auxiliary carrier is firstly the same as the above S101-S103, namely the UE completes the random access in the main carrier.

Next, after S103, the method further includes:

and the UE sends an auxiliary carrier access capability indication message of the UE to the base station, and is used for sending an RRC reconfiguration message to the UE after the base station learns the auxiliary carrier access capability of the UE, wherein the RRC reconfiguration message carries an identifier of at least one uplink auxiliary carrier, and the RRC reconfiguration message is used for indicating the UE to initiate random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

And the UE initiates random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

Specifically, the initiating, by the UE, the random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message includes:

and the UE sends a random access preamble to the base station on the uplink auxiliary carrier, so that the base station sends a random access response to the UE through the downlink main carrier, and the uplink auxiliary carrier is the uplink auxiliary carrier corresponding to the identifier of any uplink auxiliary carrier carried in the RRC reconfiguration message.

And the UE receives the random access response sent by the base station.

And the UE sends the first scheduling uplink transmission on the uplink auxiliary carrier according to the random access response.

The above process is directed to non-contention random access, and for contention random access, after the UE sends a first scheduled uplink transmission on the uplink secondary carrier according to a random access response, the method further includes:

and the UE receives a competition resolving message sent to the UE by the base station through the downlink main carrier.

In the random access method under asymmetric uplink carrier aggregation provided by this embodiment, a first random access is performed on a primary carrier, after the first random access is completed, the UE reports the access capability of an auxiliary carrier to the base station, so that the base station switches the UE to the auxiliary carrier to initiate random access, when the UE performs random access on any auxiliary carrier, a non-contention random access response is sent on a downlink primary carrier by the base station, and a contention resolution message and a contention random access response are sent on the downlink primary carrier by the base station, thereby solving the random access problem in an asymmetric uplink carrier aggregation scenario.

Fig. 3 is a flowchart of a second embodiment of a random access method under asymmetric uplink carrier aggregation according to the present invention, where the present embodiment takes a base station as an execution subject for explanation, and as shown in fig. 3, the method of the present embodiment may include:

s201, a base station receives a random access preamble sent by UE on an uplink main carrier.

Specifically, the UE sends a random access preamble to the base station on the PRACH configured on the uplink primary carrier.

S202, the base station sends a random access response to the UE through the downlink main carrier according to the random access preamble, and the random access response is used for sending first-time scheduling uplink transmission on the uplink main carrier by the UE.

Specifically, after receiving the random access preamble, the base station calculates the timing advance by using the random access preamble sequence therein, allocates channel resources and a Temporary C-RNTI to the UE, and transmits the result through a physical downlink shared channel of a downlink main carrier, which is called as a random access response. And the UE sends the first scheduling uplink transmission on the physical uplink shared channel of the uplink main carrier according to the channel resource allocation information in the random access response.

S203, the base station receives the first scheduling uplink transmission sent by the UE on the uplink main carrier.

Since the uplink secondary carrier does not have a corresponding downlink secondary carrier, in the present invention, it is specified that random access is initiated only at the primary carrier. The invention provides two random access methods:

firstly, random access is initiated only in a main carrier, and an auxiliary carrier is not provided with physical random access channel PRACH resources.

After S101-S103, after S203, the method further includes:

and the base station sends DCI0 or RRC signaling on the PDCCH to the UE, wherein the DCI0 or RRC signaling of the PDCCH carries an identifier of an uplink auxiliary carrier and is used for sending data on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier by the UE.

And the base station receives data sent by the UE on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier.

In the random access method under asymmetric uplink carrier aggregation provided by this embodiment, random access is only performed on the primary carrier, and the secondary carrier is used to send data, so that the random access problem under an asymmetric uplink carrier aggregation scenario is solved.

And secondly, the main carrier and the auxiliary carrier independently perform random access, the random access process of the main carrier is the same as the conventional random access process, the random access process of the auxiliary carrier is firstly the same as the above S101-S103, namely the UE completes the random access in the main carrier.

Next, after S203, the method further includes:

and the base station receives an auxiliary carrier access capability indication message sent by the UE.

And after acquiring the auxiliary carrier access capability of the UE, the base station sends an RRC reconfiguration message to the UE, wherein the RRC reconfiguration message carries an identifier of at least one uplink auxiliary carrier, and the RRC reconfiguration message is used for indicating the UE to initiate random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

And the base station receives the random access initiated by the UE on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

The method for receiving the random access initiated by the UE on the uplink auxiliary carrier by the base station specifically comprises the following steps:

and the base station receives a random access preamble sent by the UE on an uplink auxiliary carrier, wherein the uplink auxiliary carrier is an uplink auxiliary carrier corresponding to the identifier of any uplink auxiliary carrier carried in the RRC reconfiguration message.

And the base station sends a random access response to the UE through the downlink main carrier, and the random access response is used for sending the first-time scheduling uplink transmission on the uplink auxiliary carrier by the UE.

The above procedure is directed to non-contention random access, and for contention random access, further includes:

and the base station sends a competition resolving message to the UE through the downlink main carrier.

In the random access method under asymmetric uplink carrier aggregation provided by this embodiment, a first random access is performed on a primary carrier, after the first random access is completed, a UE reports an access capability of an auxiliary carrier to a base station, the base station switches the UE to the auxiliary carrier according to the access capability of the auxiliary carrier to initiate a random access, when the UE performs the random access on any auxiliary carrier, a non-contention random access response is sent on a downlink primary carrier by the base station, and a contention random access response and a contention resolution message are sent on the downlink primary carrier by the base station, so that a random access problem in an asymmetric uplink carrier aggregation scene is solved.

The following describes the random access method under asymmetric uplink carrier aggregation in detail with two specific embodiments.

Fig. 4 is an interactive flowchart of a third embodiment of the random access method under asymmetric uplink carrier aggregation according to the present invention, and as shown in fig. 4, in this embodiment, random access is initiated only in a primary carrier, and a secondary carrier does not allocate PRACH resources. The method of the embodiment may include:

s301, UE sends random access preamble to base station on uplink main carrier.

Specifically, the UE sends a random access preamble to the base station on the PRACH configured on the uplink primary carrier.

S302, the base station sends a random access response to the UE through the downlink main carrier according to the random access preamble.

Specifically, after receiving the random access preamble, the base station calculates the timing advance by using the random access preamble sequence therein, allocates channel resources and the Temporary C-RNTI to the UE, and transmits the random access preamble through a physical downlink shared channel of a downlink main carrier, which is called as a random access response.

And S303, after receiving the random access response sent by the base station, the UE sends the first-time scheduling uplink transmission on the uplink main carrier according to the random access response.

Specifically, the UE sends the first scheduled uplink transmission on the physical uplink shared channel of the uplink primary carrier according to the channel resource allocation information in the random access response.

S304, the base station sends RRC signaling or DCI0 on the PDCCH to the UE, and the identifier of the uplink auxiliary carrier is carried in the DCI0 or the RRC signaling.

S305, the UE sends data on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier.

Fig. 5 is an interactive flowchart of a fourth embodiment of the random access method under asymmetric uplink carrier aggregation in the present embodiment, in which a main carrier and an auxiliary carrier perform random access independently, a random access process of the main carrier is the same as an existing random access process, and a random access process of the auxiliary carrier is as follows, as shown in fig. 5:

s401, UE sends random access preamble to base station on uplink main carrier.

Specifically, the UE sends a random access preamble to the base station on the PRACH configured on the uplink primary carrier.

S402, the base station sends a random access response to the UE through the downlink main carrier according to the random access preamble.

Specifically, after receiving the random access preamble, the base station calculates the timing advance by using the random access preamble sequence therein, allocates channel resources and the Temporary C-RNTI to the UE, and transmits the random access preamble through a physical downlink shared channel of a downlink main carrier, which is called as a random access response.

And S403, after receiving the random access response sent by the base station, the UE sends the first-time scheduling uplink transmission on the uplink main carrier according to the random access response.

Specifically, the UE sends the first scheduled uplink transmission on the physical uplink shared channel of the uplink primary carrier according to the channel resource allocation information in the random access response.

The random access procedure on the primary carrier is completed via S401-S403, and then, after S403, the method further includes:

s404, the UE sends an auxiliary carrier access capability indication message of the UE to the base station.

S405, after learning the auxiliary carrier access capability of the UE, the base station sends an RRC reconfiguration message to the UE, wherein the RRC reconfiguration message carries an identifier of at least one uplink auxiliary carrier, and the RRC reconfiguration message is used for indicating the UE to initiate random access on the uplink auxiliary carrier corresponding to the identifier of the uplink auxiliary carrier carried in the RRC reconfiguration message.

S406, the UE sends a random access preamble to the base station on the uplink auxiliary carrier, wherein the uplink auxiliary carrier is the uplink auxiliary carrier corresponding to the identifier of any uplink auxiliary carrier carried in the RRC reconfiguration message.

S407, the base station sends a random access response to the UE through the downlink main carrier.

S408, the UE sends the first scheduling uplink transmission on the uplink auxiliary carrier according to the random access response.

The above procedure is directed to non-contention random access, and for contention random access, after S408, the method further includes:

s409, the base station sends competition resolving information to the UE through the downlink main carrier.

The user equipment in the embodiment shown in fig. 6 corresponds to a technical solution that can be used to execute the method embodiment shown in fig. 2, and the implementation principle and technical effect are similar, and are not described herein again.

The base station in the embodiment shown in fig. 7 is capable of implementing the technical solution in the embodiment shown in fig. 3, and the implementation principle and technical effect are similar, which are not described herein again.

Those of ordinary skill in the art will understand that: all or a portion of the steps of implementing the above-described method embodiments may be performed by hardware associated with program instructions. The program may be stored in a computer-readable storage medium. When executed, the program performs steps comprising the method embodiments described above; and the aforementioned storage medium includes: various media that can store program codes, such as ROM, RAM, magnetic or optical disks.

Finally, it should be noted that: the above embodiments are only used to illustrate the technical solution of the present invention, and not to limit the same; while the invention has been described in detail and with reference to the foregoing embodiments, it will be understood by those skilled in the art that: the technical solutions described in the foregoing embodiments may still be modified, or some or all of the technical features may be equivalently replaced; and the modifications or the substitutions do not make the essence of the corresponding technical solutions depart from the scope of the technical solutions of the embodiments of the present invention.