CN106535345B

CN106535345B - Method for adjusting channel interception threshold and base station

Info

Publication number: CN106535345B
Application number: CN201510587222.2A
Authority: CN
Inventors: 谷俊嵘; 刘建国; 韩锋; 陶涛; 孟艳; 沈钢
Original assignee: Alcatel Lucent SAS
Current assignee: Alcatel Lucent SAS
Priority date: 2015-09-15
Filing date: 2015-09-15
Publication date: 2020-02-28
Anticipated expiration: 2035-09-15
Also published as: CN106535345A

Abstract

The embodiment of the disclosure relates to a method and a base station for adjusting a channel sensing threshold value. The method can comprise the following steps: determining that communication performance related to a channel sensing threshold is below a predetermined level; determining an optimal channel listening threshold value for optimizing communication performance; and adjusting the current channel sensing threshold based on the optimal channel sensing threshold. The embodiment of the disclosure adopts a channel interception adaptive channel interception threshold adjustment design, so that the possible problems of hidden nodes and exposed nodes can be avoided, and the limitation of adjusting the channel interception threshold in a single base station can be broken through, thereby solving the problems in the prior art.

Description

Method for adjusting channel interception threshold and base station

Technical Field

Embodiments of the present disclosure relate generally to the field of wireless communication technology, and in particular, to a method of adjusting a channel sensing threshold and a base station.

Background

The long term evolution, LTE, of the third generation partnership project, 3GPP, which is conventionally deployed in licensed bands, is facing a tremendous increase in data traffic. Even though LTE is able to efficiently utilize spectrum, the frequency band licensed for LTE is very limited and is exclusively reserved. Therefore, LTE is being considered for deployment in unlicensed bands below 6GHz, which will become LTE-assisted access (LAA) for unlicensed band deployment. Moreover, the performance of LAA has been superior to WiFi (e.g., 802.11ac) primarily due to the highly scheduled nature. Thus, LAA becomes a promising candidate for the next phase of LTE that operators will deploy.

During wireless communication, the interference to each base station of LTE-assisted access (LAA) is likely to be different due to the complex radio environment. However, when they attempt to channel sense (CCA or eCCA) in accordance with the Listen Before Talk (LBT) procedure, current practice is to employ a constant channel sensing threshold. Therefore, when an inappropriate channel sensing threshold is set in the base station, the base station may encounter one of the following two problems. For one, even if channel sensing indicates that the channel is not interfering, it is strongly interfered when delivering data, so that the signal to interference noise ratio SINR is very low when some number of UEs (edge UEs) receive data. This is a hidden node problem. Second, although the channel condition is reported as good, the system throughput is bad or very low, i.e., has good SINR, but the transmission chance is less. This is an exposed node problem.

The above two problems occur because the channel sensing of the base station sets the threshold value unreasonably. Obviously, each base station requires an appropriate channel sensing threshold. In this regard, the adjustment of the channel sensing threshold has been agreed as a research project in the 3GPP 80bis conference. Furthermore, the channel sensing threshold should be adaptive to the complex radio environment, so that the UE has satisfactory performance, e.g. good SINR and throughput.

Disclosure of Invention

In view of the above problems in the prior art, an object of the embodiments of the present disclosure is to provide a method for adjusting a channel sensing threshold and a base station, which adopt an adaptive channel sensing threshold adjustment design for channel sensing, so that LAA can avoid the possible hidden node problem and the exposed node problem, and can break through the limitation of channel sensing threshold adjustment in a single base station, thereby solving the above and other problems in the prior art.

According to a first aspect of the present disclosure, there is provided a method of adjusting a channel sensing threshold, the method may include: determining that communication performance related to a channel sensing threshold is below a predetermined level; determining an optimal channel listening threshold value for optimizing communication performance; and adjusting the current channel sensing threshold based on the optimal channel sensing threshold.

In some embodiments, determining an optimal channel sensing threshold that optimizes communication performance may include: and determining the optimal channel interception threshold value which enables the communication performance to be optimal within the preset value interval of the channel interception threshold value.

In some embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: and adjusting the current channel sensing threshold value towards the optimal channel sensing threshold value.

In some embodiments, determining the optimal channel sensing threshold that optimizes the communication performance within the predetermined value interval of the channel sensing threshold may include: and if the communication performance is better than the lower limit at the upper limit of the preset value interval and is better than the left adjacent domain of the upper limit at the upper limit, determining that the optimal channel interception threshold is the upper limit of the preset value interval. In these embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: the current channel sensing threshold is increased by a first step size.

In some embodiments, determining the optimal channel sensing threshold that optimizes the communication performance within the predetermined value interval of the channel sensing threshold may include: and if the communication performance is better than the lower limit at the upper limit of the preset value range and better than the upper limit at the left adjacent domain of the upper limit, determining that the optimal channel interception threshold is positioned between the upper limit and the lower limit of the preset value range. In these embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: and if the current channel sensing threshold value is smaller than the optimal channel sensing threshold value, increasing the current channel sensing threshold value by a first step length, and if the current channel sensing threshold value is larger than the optimal channel sensing threshold value, decreasing the current channel sensing threshold value by the first step length. In some embodiments, a binary search method may be used to determine the optimal channel sensing threshold.

In some embodiments, determining the optimal channel sensing threshold that optimizes the communication performance within the predetermined value interval of the channel sensing threshold may include: and if the communication performance is better than the upper limit at the lower limit of the preset value interval and is better than the right neighborhood of the lower limit at the lower limit, determining the optimal channel interception threshold as the lower limit of the preset value interval. In these embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: the current channel sensing threshold is decreased by a first step size.

In some embodiments, determining the optimal channel sensing threshold that optimizes the communication performance within the predetermined value interval of the channel sensing threshold may include: and if the communication performance is better than the upper limit at the lower limit of the preset value range and better than the lower limit in the right neighborhood of the lower limit, determining that the optimal channel interception threshold is positioned between the upper limit and the lower limit of the preset value range. In these embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: and if the current channel sensing threshold value is smaller than the optimal channel sensing threshold value, increasing the current channel sensing threshold value by a first step length, and if the current channel sensing threshold value is larger than the optimal channel sensing threshold value, decreasing the current channel sensing threshold value by the first step length. In some embodiments, a binary search method may be used to determine the optimal channel sensing threshold.

In some embodiments, the method may further comprise: and when the communication performance is not lower than the preset level, stopping adjusting the current channel interception threshold value.

In some embodiments, when the current channel sensing threshold has been adjusted to the optimal channel sensing threshold and the communication performance is still below a predetermined level, the method may further comprise: sending a request message to the adjacent base station to request the adjacent base station to adjust the channel interception threshold value; receiving a notification message from the neighboring base station to notify the neighboring base station that its channel sensing threshold has been adjusted; determining whether the communication performance is below a predetermined level in response to receiving the notification message; and if the communication performance is below a predetermined level, transmitting the request message to the neighboring base station again and repeating the aforementioned steps; if the communication performance is not lower than the predetermined level, the transmission of the request message to the neighbor base station is stopped.

In some embodiments, X2 signaling may be used to communicate with neighboring base stations.

In some embodiments, the communication performance may include a short-time communication throughput.

In some embodiments, the method may be performed semi-statically.

In some embodiments, the method may be performed with the assistance of a user device.

According to a second aspect of the present disclosure, there is provided a method of adjusting a channel sensing threshold, the method may include: receiving a request message from a neighboring base station, the request message requesting adjustment of a channel listening threshold; determining an optimum channel listening threshold value that optimizes communication performance with respect to the channel listening threshold value in response to the request message; adjusting a current channel sensing threshold based on the optimal channel sensing threshold while maintaining communication performance not below a predetermined level; and sending a notification message to the neighboring base station to notify the neighboring base station that the channel sensing threshold has been adjusted.

In some embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: and adjusting the current channel interception threshold value to be far away from the optimal channel interception threshold value.

In some embodiments, determining the optimal channel sensing threshold that optimizes the communication performance within the predetermined value interval of the channel sensing threshold may include: and if the communication performance is better than the lower limit at the upper limit of the preset value interval and is better than the left adjacent domain of the upper limit at the upper limit, determining that the optimal channel interception threshold is the upper limit of the preset value interval. In these embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: the current channel sensing threshold is decreased by a second step size.

In some embodiments, determining the optimal channel sensing threshold that optimizes the communication performance within the predetermined value interval of the channel sensing threshold may include: and if the communication performance is better than the lower limit at the upper limit of the preset value range and better than the upper limit at the left adjacent domain of the upper limit, determining that the optimal channel interception threshold is positioned between the upper limit and the lower limit of the preset value range. In these embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: and if the current channel sensing threshold value is smaller than the optimal channel sensing threshold value, reducing the current channel sensing threshold value by a second step length, and if the current channel sensing threshold value is larger than the optimal channel sensing threshold value, increasing the current channel sensing threshold value by the second step length. In some embodiments, the optimal channel sensing threshold is determined using a binary search method.

In some embodiments, determining the optimal channel sensing threshold that optimizes the communication performance within the predetermined value interval of the channel sensing threshold may include: and if the communication performance is better than the upper limit at the lower limit of the preset value interval and is better than the right neighborhood of the lower limit at the lower limit, determining the optimal channel interception threshold as the lower limit of the preset value interval. In these embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: the current channel sensing threshold is increased by a second step size.

In some embodiments, determining the optimal channel sensing threshold that optimizes the communication performance within the predetermined value interval of the channel sensing threshold may include: and if the communication performance is better than the upper limit at the lower limit of the preset value range and better than the lower limit in the right neighborhood of the lower limit, determining that the optimal channel interception threshold is positioned between the upper limit and the lower limit of the preset value range. In these embodiments, adjusting the current channel sensing threshold based on the optimal channel sensing threshold may include: and if the current channel sensing threshold value is smaller than the optimal channel sensing threshold value, reducing the current channel sensing threshold value by a second step length, and if the current channel sensing threshold value is larger than the optimal channel sensing threshold value, increasing the current channel sensing threshold value by the second step length. In some embodiments, the optimal channel sensing threshold is determined using a binary search method.

According to a third aspect of the present disclosure, there is provided a base station, which may include: a first determination unit configured to determine that communication performance related to a channel sensing threshold is lower than a predetermined level; a second determination unit configured to determine an optimal channel listening threshold value that optimizes communication performance; and an adjusting unit configured to adjust the current channel sensing threshold based on the optimal channel sensing threshold.

According to a fourth aspect of the present disclosure, there is provided a base station, which may include: a receiving unit configured to receive a request message from a neighboring base station, the request message to request adjustment of a channel listening threshold; a determination unit configured to determine, in response to the request message, an optimum channel listening threshold value that optimizes communication performance with respect to the channel listening threshold value; an adjusting unit configured to adjust a current channel listening threshold based on the optimal channel listening threshold while maintaining communication performance not lower than a predetermined level; and a transmitting unit configured to transmit a notification message to the neighboring base station to notify the neighboring base station that the channel sensing threshold has been adjusted.

Embodiments of the present disclosure provide adaptive channel sensing (CCA, eCCA) threshold adjustment designs, such that LAA may avoid possible hidden node problems and exposed node problems, and may break through the limitation of channel sensing threshold adjustment within a single base station.

Drawings

The above and other objects, features and advantages of the embodiments of the present disclosure will become readily apparent from the following detailed description read in conjunction with the accompanying drawings. In the drawings:

fig. 1 schematically illustrates the hidden node problem caused by too high a channel sensing threshold of a base station.

Figure 2 schematically illustrates the exposed node problem caused by a too low channel sensing threshold of the base station.

Fig. 3 schematically shows the relationship between the throughput of the base station and the channel sensing threshold.

Fig. 4 schematically illustrates a method for adjusting a channel sensing threshold according to an embodiment of the present disclosure.

Fig. 5 schematically illustrates another method for adjusting a channel sensing threshold according to an embodiment of the present disclosure.

Fig. 6 schematically illustrates a method for adjusting a channel sensing threshold between base stations according to an embodiment of the present disclosure.

Fig. 7 schematically illustrates a base station according to an embodiment of the present disclosure.

Fig. 8 schematically illustrates another base station according to an embodiment of the present disclosure.

Detailed Description

The principles and spirit of the present disclosure will be described with reference to a number of exemplary embodiments shown in the drawings. It is understood that these specific embodiments are described merely to enable those skilled in the art to better understand and implement the embodiments of the present disclosure, and are not intended to limit the scope of the present disclosure in any way.

Fig. 1 and 2 schematically illustrate two possible problems due to unreasonable channel sensing thresholds used by a base station, namely a hidden node problem and an exposed node problem, respectively. In the hidden node problem shown in fig. 1, the listening range of the base station is small and cannot detect nodes of other RATs/operators, but the nodes can cause interference to wireless communication between the base station and the UE. In contrast, in the exposed node problem shown in fig. 2, the base station has an excessively large listening range and detects nodes of other RATs/operators, but in fact the node does not interfere with the wireless communication between the base station and the UE.

As described above, these two problems occur because the channel-sensing threshold of the base station is not set reasonably. Obviously, each base station needs to set an appropriate channel sensing threshold. To solve this problem, embodiments of the present disclosure provide a method of adjusting a channel sensing threshold and a base station. Hereinafter, a relationship between throughput of a base station and its channel sensing threshold in a general wireless communication environment will first be provided, and on this basis, a method of adjusting a channel sensing threshold and a base station according to an embodiment of the present disclosure will be further specifically described.

Fig. 3 schematically shows the relationship between the throughput of the base station and the channel sensing threshold. As shown in fig. 3, there may be three possible cases as follows for the relationship between the throughput of the base station and the channel sensing threshold. Those skilled in the art will appreciate that adjusting the channel sensing threshold actually provides a compromise between the number and quality of discovered spectrum opportunities. This trade-off is directly related to the throughput of the base station, which is a major system performance indicator of concern to most people.

As shown in fig. 3, in case 1, the maximum value of the throughput is between the lower limit and the upper limit of the channel sensing threshold, the throughput first increases as the channel sensing threshold increases, and starts to decrease after reaching the maximum value. The throughput curves in case 2 and case 3 can be viewed as a translation of the throughput curves in case 1. In case 2, the throughput monotonically decreases as the channel sensing threshold increases between the lower and upper limits. In case 3, the throughput monotonically increases as the channel sensing threshold increases between the lower and upper limits.

Each of these three cases occurs under different interference conditions and accordingly, different adjustments to the channel-sensing threshold will be made. Thus, the base station will periodically identify in which case the relationship between its throughput and the threshold is. Without loss of generality, a specific method of identifying in which case the relationship between its throughput and a threshold is based on monotonicity is presented below, taking as an example one base station in a wireless communication network.

Let η₁For the channel sensing threshold of the base station, TP_ηmaxAnd TP_ηminAre respectively η₁＝η_maxAnd η_minShort time throughput of time △ is a small positive value, TP_ηmax’And TP_ηmin’Respectively when η₁＝η_max- △ and η_minShort time throughput at + △.

The specific method for identifying the case in which the relationship between the throughput of the base station and the threshold is: if TP_ηmax>TP_ηminAnd TP_ηmax>TP_ηmax’Then it may be determined that the base station is in case 3, otherwise it may be determinedThe fixed base station is in case 1. If TP_ηmax<TP_ηminAnd TP_ηmin>TP_ηmin’Then the base station may be determined to be in case 2, otherwise the base station may be determined to be in case 1.

Fig. 4 schematically illustrates a method 400 of adjusting a channel sensing threshold according to an embodiment of the disclosure. The method 400 may be performed by a base station in a wireless communication network, in particular, the method 400 may be performed by a base station 700 described later herein with reference to fig. 7.

As shown in fig. 4, method 400 may proceed to step 401 after starting. In step 401, a base station performing method 400 may determine that communication performance related to a channel sensing threshold is below a predetermined level. In response to this determination, the base station performing method 400 may begin adjusting its current channel sensing threshold.

Those skilled in the art will appreciate that the communication performance in step 401 may be, for example, the short-time throughput or a parameter related to the short-time throughput, or may be other suitable parameters capable of reflecting the communication performance. In this regard, a person skilled in the art may select specific parameters capable of characterizing communication performance according to specific application scenarios and technical environments, and embodiments of the present disclosure are not limited in this respect. Those skilled in the art will also appreciate that in step 401, "associated with" the channel sensing threshold means that the communication performance is associated with the channel sensing threshold. In other words, by adjusting the channel sensing threshold, the communication performance can be adjusted accordingly. In particular, the communication performance may have a relationship with a channel sensing threshold similar to that as depicted in fig. 3. It will be further appreciated by those skilled in the art that the predetermined level in step 401 may be predetermined according to the relevant technical scenario and requirements.

The method 400 may then proceed to step 402. In step 402, the base station performing the method 400 may determine an optimal channel sensing threshold that optimizes communication performance.

As described above, the communication performance may be associated with a channel sensing threshold. Therefore, an optimal channel-sensing threshold value that optimizes communication performance can be determined using an appropriate method. For example, the optimal channel sensing threshold may be determined using methods described later herein. However, it should be understood that other methods known in the art may be used by one skilled in the art to determine the optimal channel sensing threshold, and embodiments of the present disclosure are not limited in this respect. In particular, the optimal channel listening threshold may be a maximum value on a curve of throughput versus channel listening threshold as depicted in fig. 3.

According to some embodiments of the disclosure, step 402 may further comprise: and determining the optimal channel interception threshold value which enables the communication performance to be optimal within the preset value interval of the channel interception threshold value. As will be understood by those skilled in the art, the base station may have a predetermined value interval for the value of the channel sensing threshold. In this case, the step of determining the optimal channel sensing threshold may be simplified to determine the optimal channel sensing threshold within the predetermined value range.

According to some embodiments of the present disclosure, if the communication performance is better at the upper limit of the predetermined value interval than at the lower limit and better at the upper limit than at the left neighborhood of the upper limit, the optimal channel listening threshold may be determined to be the upper limit of the predetermined value interval. This case may correspond to case 3 as shown by the dashed line in fig. 3. As shown in fig. 3, in case 3, the throughput is monotonically increasing within the predetermined span of the channel sensing threshold, and the peak throughput is reached when the channel sensing threshold reaches the upper limit of the predetermined span.

According to some embodiments of the present disclosure, if the communication performance is better at the upper limit and better at the left neighborhood of the upper limit of the predetermined span, it may be determined that the optimal channel listening threshold is between the upper limit and the lower limit of the predetermined span. This case may correspond to case 1 as shown by the solid line in fig. 3. As shown in fig. 3, in case 1, the throughput undergoes a first-rising and then-falling change process within a predetermined value interval of the channel sensing threshold, and when the channel sensing threshold reaches a certain value between the lower limit and the upper limit of the predetermined value range, the peak throughput is reached.

According to some embodiments of the present disclosure, if the communication performance is better at the lower limit of the predetermined span than at the upper limit and better at the lower limit than at the right neighborhood of the lower limit, the optimal channel listening threshold is determined to be the lower limit of the predetermined span. This case may correspond to case 2 as shown by the dashed line in fig. 3. As shown in fig. 3, in case 2, the throughput is monotonically decreasing within the predetermined span of the channel sensing threshold, and the peak throughput is reached when the channel sensing threshold reaches the lower limit of the predetermined span.

According to some embodiments of the present disclosure, if the communication performance is better at the upper limit at the lower limit and better at the lower limit in the right neighborhood of the lower limit of the predetermined span, it is determined that the optimal channel sensing threshold is between the upper limit and the lower limit of the predetermined span. This case may correspond to case 1 as shown by the solid line in fig. 3. As shown in fig. 3, in case 1, the throughput undergoes a first-rising and then-falling change process within a predetermined value interval of the channel sensing threshold, and when the channel sensing threshold reaches a certain value between the lower limit and the upper limit of the predetermined value range, the peak throughput is reached.

The method 400 may then proceed to step 403. In step 403, the base station performing the method 400 may adjust the current channel sensing threshold based on the optimal channel sensing threshold.

Those skilled in the art will appreciate that once the optimal channel sensing threshold is determined, the base station performing the method 400 may adjust the current channel sensing threshold according to the determined optimal channel sensing threshold in order to optimize the current channel sensing threshold. It will also be appreciated by those skilled in the art that various specific modifications may be made. For example, the adjustment may be made using an adjustment manner described later herein, or may be made using other adjustment manners known in the art, and the present disclosure is not limited in this respect.

According to some embodiments of the present disclosure, step 403 may further include: and adjusting the current channel sensing threshold value towards the optimal channel sensing threshold value. As shown in fig. 3, in a general case, no matter which situation a channel sensing threshold-throughput relation curve is in fig. 3, adjusting a current channel sensing threshold towards the determined optimal channel sensing threshold can optimize throughput. That is, optimizing communication performance is actually equivalent to making the value of the channel sensing threshold closer to the optimal channel sensing threshold under normal circumstances.

According to some embodiments of the present disclosure, if it is determined that the optimal channel sensing threshold is the upper limit of the predetermined value interval, step 403 may further include: the current channel sensing threshold is increased by a first step size. This case may correspond to case 3 as shown by the dashed line in fig. 3. As shown in fig. 3, in case 3, increasing the current channel sensing threshold in a predetermined span may increase throughput.

According to some embodiments of the present disclosure, if it is determined that the optimal channel sounding threshold is the lower limit of the predetermined value interval, step 403 may further include: the current channel sensing threshold is decreased by a first step size. This case may correspond to case 2 as shown by the dashed line in fig. 3. As shown in fig. 3, in case 2, decreasing the current channel sensing threshold in a predetermined interval may increase throughput.

According to some embodiments of the present disclosure, if it is determined that the optimal channel sensing threshold is located between the upper limit and the lower limit of the predetermined value interval, step 403 may further include: and if the current channel sensing threshold value is smaller than the optimal channel sensing threshold value, increasing the current channel sensing threshold value by a first step length, and if the current channel sensing threshold value is larger than the optimal channel sensing threshold value, decreasing the current channel sensing threshold value by the first step length. This case may correspond to case 1 as shown by the solid line in fig. 3. As shown in fig. 3, in case 1, if the current channel sensing threshold is less than the optimal channel sensing threshold, the current channel sensing threshold should be increased so as to be close to the optimal channel sensing threshold; if the current channel sensing threshold is greater than the optimal channel sensing threshold, the current channel sensing threshold should be decreased so as to be close to the optimal channel sensing threshold. According to some embodiments of the present disclosure, a binary search may be used to determine the optimal channel sensing threshold in order to compare it with the current channel sensing threshold. Those skilled in the art will appreciate that binary search is only one exemplary method of numerical analysis methods for determining the optimal channel sensing threshold, and that other known suitable numerical analysis methods may be used to determine the optimal channel sensing threshold, and embodiments of the present disclosure are not limited in this respect.

According to some embodiments of the disclosure, the method 400 may further comprise: and when the communication performance is not lower than the preset level, stopping adjusting the current channel interception threshold value. Those skilled in the art will appreciate that after one adjustment to the channel sensing threshold, the base station performing method 400 may determine whether the communication performance after the adjustment is below a predetermined level. The base station performing method 400 may stop adjusting the channel sensing threshold if the communication performance is no longer below the predetermined level. If the communication performance is still below the predetermined level, the base station performing the method 400 may again adjust the channel sensing threshold as per the flow of the method 400 until the communication performance is no longer below the predetermined level.

Embodiments of the present disclosure also recognize that channel sensing threshold adjustment is very limited within a single base station, primarily due to unintentional interference/transmissions from nearby base stations or other nodes. If the channel-sensing threshold of the base station is reduced to reduce hidden nodes, while also reducing the number of transmission opportunities, throughput may be severely reduced due to this reduction. If the channel-sensing threshold is increased for an exposed node, the number of transmission opportunities that suffer interference is also increased, and throughput increase is not guaranteed.

Therefore, channel sensing threshold adjustment between base stations is necessary. In order to solve the problem of inappropriate channel sensing threshold, the embodiment of the disclosure also provides an adaptive adjustment method via an X2 interface, and defines a corresponding mechanism.

When a communication performance problem occurs with respect to the channel-sensing threshold, the base station will attempt to solve this problem by adjusting its own channel-sensing threshold. The effect of adjusting the channel-sensing threshold within a single base station is limited and, in addition to addressing the original problems, may cause unexpected problems, such as reduced throughput while reducing hidden nodes.

If the base station cannot solve the problem related to the channel sensing threshold by adjusting its own channel sensing threshold, the base station will request the neighboring interfering base station to adjust its threshold(s). The neighboring interfering base station will decide whether to adjust its own threshold and reply to the request accordingly. Further, the adjustment of the channel sensing threshold may be semi-static. Embodiments of the present disclosure also define signaling for channel sensing threshold adjustment between base stations. It is further noted that when the dominant interfering base station belongs to the same operator as the interfered base station, then the identity of the dominant interfering base station may be detected. Based on this, the request to adjust the channel sensing threshold may be sent only to this neighboring base station. In addition to this, the adjustment of the channel sensing threshold may also be UE-assisted.

In the foregoing steps of the method 400 described above, according to some embodiments of the present disclosure, when the current channel sensing threshold has been adjusted to the optimal channel sensing threshold and the communication performance is still below a predetermined level, the base station performing the method 400 may send a request message to the neighboring base station to request the neighboring base station to adjust its channel sensing threshold. According to some embodiments of the present disclosure, after a neighboring base station has adjusted its channel sensing threshold, the base station performing method 400 may receive a notification message from the neighboring base station to notify the neighboring base station that its channel sensing threshold has been adjusted. According to some embodiments of the present disclosure, a base station performing method 400 may determine whether communication performance is below a predetermined level in response to receiving a notification message. If the communication performance is below the predetermined level, the base station performing the method 400 may again transmit the request message to the neighboring base station and repeat the foregoing steps; the base station performing the method 400 may stop sending request messages to neighboring base stations if the communication performance is not below a predetermined level.

According to some embodiments of the present disclosure, a base station performing method 400 may communicate with a neighboring base station using X2 signaling. According to some embodiments of the disclosure, a base station performing method 400 may perform method 400 semi-statically. According to some embodiments of the disclosure, a base station performing the method 400 may perform the method 400 with the assistance of a user equipment. In this regard, the base station may obtain, for example, some information useful for making channel sensing threshold adjustments from the user equipment, such as signal strength, quality of service, etc. of the edge user equipment.

Fig. 5 schematically illustrates another method 500 of adjusting a channel sensing threshold according to an embodiment of the disclosure. The method 500 may be performed by a base station in a wireless communication network, in particular, the method 500 may be performed by the base station 800 described later herein with reference to fig. 8.

As shown in fig. 5, method 500 may proceed to step 501 after starting. In step 501, a base station performing method 500 may receive a request message from a neighboring base station requesting an adjustment to a channel sensing threshold. In particular, the neighboring base station of the base station performing the method 500 may be the base station performing the method 400 as depicted in fig. 4. In response to this request message, the base station performing method 500 may begin adjusting its current channel sensing threshold.

Method 500 may then proceed to step 502. In step 502, the base station performing method 500 may determine an optimal channel sensing threshold that optimizes communication performance with respect to the channel sensing threshold in response to the request message.

Those skilled in the art will appreciate that the communication performance in step 502 may be, for example, the short-time throughput or a parameter related to the short-time throughput, or may be other suitable parameters capable of reflecting the communication performance. In this regard, a person skilled in the art may select specific parameters capable of characterizing communication performance according to specific application scenarios and technical environments, and embodiments of the present disclosure are not limited in this respect. Those skilled in the art will also appreciate that in step 502, "associated with" the channel sensing threshold means that the communication performance is associated with the channel sensing threshold. In other words, by adjusting the channel sensing threshold, the communication performance can be adjusted accordingly. In particular, the communication performance may have a relationship with a channel sensing threshold similar to that as depicted in fig. 3.

According to some embodiments of the disclosure, step 502 may further comprise: and determining the optimal channel interception threshold value which enables the communication performance to be optimal within the preset value interval of the channel interception threshold value. As will be understood by those skilled in the art, the base station may have a predetermined value interval for the value of the channel sensing threshold. In this case, the step of determining the optimal channel sensing threshold may be simplified to determine the optimal channel sensing threshold within the predetermined value range.

The method 500 may then proceed to step 503. In step 503, the base station performing the method 500 may adjust the current channel sensing threshold based on the optimal channel sensing threshold while maintaining communication performance not below a predetermined level.

Those skilled in the art will appreciate that once the optimal channel sensing threshold is determined, the base station executing the method 500 may adjust the current channel sensing threshold according to the determined optimal channel sensing threshold, so as to reduce the optimization level of the current channel sensing threshold, thereby reducing the interference to the base station sending the request message. It should be noted, however, that the base station performing method 500 should reduce its interference with the base station sending the request while maintaining its communication performance not below a predetermined level. Those skilled in the art will appreciate that the predetermined level in step 503 may be predetermined according to the relevant technical scenario and technical requirements. Those skilled in the art will also appreciate that there may be a variety of different specific ways to adjust the channel-sensing threshold. For example, the adjustment may be made using an adjustment manner described later herein, or may be made using other adjustment manners known in the art, and the present disclosure is not limited in this respect.

According to some embodiments of the present disclosure, step 503 may further comprise: and adjusting the current channel interception threshold value to be far away from the optimal channel interception threshold value. As shown in fig. 3, in a general case, no matter which situation the channel sensing threshold-throughput relation curve is in fig. 3, adjusting the current channel sensing threshold away from the determined optimal channel sensing threshold can reduce the throughput by an optimized level. That is, the level of optimization to reduce the communication performance is actually equivalent to making the value of the channel sensing threshold farther from the optimal channel sensing threshold under the normal circumstances.

According to some embodiments of the present disclosure, if it is determined that the optimal channel sensing threshold is the upper limit of the predetermined value interval, step 503 may further include: the current channel sensing threshold is decreased by a second step size. This case may correspond to case 3 as shown by the dashed line in fig. 3. As shown in fig. 3, in case 3, decreasing the current channel sensing threshold in a predetermined interval may decrease throughput.

According to some embodiments of the present disclosure, if it is determined that the optimal channel sounding threshold is the lower limit of the predetermined value interval, step 503 may further include: the current channel sensing threshold is decreased by a second step size. This case may correspond to case 2 as shown by the dashed line in fig. 3. As shown in fig. 3, in case 2, increasing the current channel sensing threshold in a predetermined interval may decrease the throughput.

According to some embodiments of the present disclosure, if it is determined that the optimal channel sensing threshold is located between the upper limit and the lower limit of the predetermined value interval, step 503 may further include: and if the current channel sensing threshold value is smaller than the optimal channel sensing threshold value, reducing the current channel sensing threshold value by a second step length, and if the current channel sensing threshold value is larger than the optimal channel sensing threshold value, increasing the current channel sensing threshold value by the second step length. This case may correspond to case 1 as shown by the solid line in fig. 3. As shown in fig. 3, in case 1, if the current channel sensing threshold is less than the optimal channel sensing threshold, the current channel sensing threshold should be decreased so as to be away from the optimal channel sensing threshold; if the current channel sensing threshold is greater than the optimal channel sensing threshold, the current channel sensing threshold should be increased so as to be away from the optimal channel sensing threshold. According to some embodiments of the present disclosure, a binary search may be used to determine the optimal channel sensing threshold in order to compare it with the current channel sensing threshold. Those skilled in the art will appreciate that binary search is only one exemplary method of numerical analysis methods for determining the optimal channel sensing threshold, and that other known suitable numerical analysis methods may be used to determine the optimal channel sensing threshold, and embodiments of the present disclosure are not limited in this respect.

The method 500 may then proceed to step 504. In step 504, the base station performing method 500 may send a notification message to the neighboring base station to notify the neighboring base station that the channel sensing threshold has been adjusted. According to some embodiments of the present disclosure, a base station performing method 500 may communicate with a neighboring base station using X2 signaling. Upon completion of step 504, method 500 may end.

Fig. 6 schematically illustrates a method 600 for adjusting a channel sensing threshold between base stations according to an embodiment of the disclosure. It should be understood that although fig. 6 depicts a particular method 600 illustrating particular embodiments of the present disclosure in a flowchart of particular steps, these particular steps are for illustrative purposes only and are not intended to limit the scope of the present disclosure in any way.

Those skilled in the art will appreciate that there are a variety of performance metrics that may be selected as measures for communication performance in relation to the channel sensing threshold. In the method 600, a short time throughput TP is illustratively used_tempTo characterize communication performance. According to some embodiments of the present disclosure, each base station should have its TP_tempGreater than a predefined value TP in order to ensure its communication performance, without loss of generality, η is separately ordered₁Channel sensing threshold of base station for initiating channel sensing threshold adjustment procedure, η_1pFor its optimal channel sensing threshold, η₂Channel sensing threshold for interfering base stations adjacent thereto, η_2pThe threshold is sensed for its optimal channel.

First, a base station in a wireless communication network can obtain a short time throughput TP_tempThe statistical data of (1). In step 601, when TP is present_tempLess than the predefined value TP, the base station may initiate an adjustment of the channel sensing threshold. Otherwise, when TP_tempNot less than the predefined value TP, the flow of method 600 may stop.

In step 602, the base station may adjust its channel sensing threshold according to which of three cases, as depicted in fig. 3, the relationship between its throughput and the channel sensing threshold is. For a specific determination method, reference may be made to the above description, which is not repeated herein.

If case 1, then when η₁<η_1pThen increase η in steps S1₁Otherwise, decrease η by step S1₁If case 2, decrease η by step S1₁If case 3, increase η in step S1₁As mentioned above, wherein η_1pThe value of (d) can be determined by a binary search method.

If after performing step 602 several times, in case 1, η₁＝η_1pWhen the temperature of the water is higher than the set temperature,or in case 2 when η₁Is reduced to η_minWhen, or in case 3, when η₁Is increased to η_maxTime, TP_tempStill less than TP, the base station may decide to request the neighboring interfering base stations for channel sensing threshold adjustment via X2 signaling in step 603. Otherwise, the base station may stop adjusting the channel sensing threshold and the flow of method 600 may stop.

In step 604, when the neighboring interfering base station receives the request to adjust the channel-sensing threshold, the neighboring interfering base station may similarly adjust its channel-sensing threshold according to which of the three cases as depicted in fig. 3 the relationship between its throughput and the channel-sensing threshold is.

If case 1, then when η₂>η_2pThen increase η in steps S2₂Otherwise, decrease η by step S2₂If case 2, increase η in step S2₂If case 3, decrease η by step S2₁. Note that the neighboring interfering base station should maintain its throughput TP at the same time in the process of adjusting the channel-sensing threshold_temp>TP。

In step 605, the neighboring interfering base station may reply to the base station sending the request message via X2 signaling: the channel sensing threshold has been adjusted.

In step 606, if the TP of the base station initiating the adjustment is the same as the TP of the base station initiating the adjustment_tempIf greater than TP, the adjustment of the channel sensing threshold may be stopped. Otherwise, the base station will again request the neighboring interfering base stations to adjust the channel sensing threshold.

According to some embodiments of the present disclosure, the neighboring interfering base stations may employ the same channel sensing threshold adjustment procedure as the base station transmitting the request message. They may move towards a common goal of maximizing their throughput. Those skilled in the art will appreciate that neighboring interfering base stations may react to the request to adjust the channel-sensing threshold in various ways known in the art, and embodiments of the present disclosure are not limited in this respect.

According to some embodiments of the present disclosure, the adjustment of the channel sensing threshold may be semi-static. In this regard, the base station may perform the identification of the aforementioned three cases on a much larger time scale than the channel sensing threshold adjustment.

Fig. 7 schematically shows a block diagram of a base station 700 according to an embodiment of the present disclosure. In some embodiments of the present disclosure, the base station 700 may be configured to perform the method 400 described above with reference to fig. 4. As shown in fig. 7, the base station 700 may include a first determining unit 701, a second determining unit 702, and an adjusting unit 703.

According to some embodiments of the present disclosure, the first determining unit 701 may be configured to determine that the communication performance related to the channel sensing threshold is below a predetermined level. The second determining unit 702 may be configured to determine an optimal channel sensing threshold value that optimizes communication performance. The adjusting unit 703 may be configured to adjust the current channel sensing threshold based on the optimal channel sensing threshold.

According to some embodiments of the present disclosure, the second determining unit 702 may be further configured to determine an optimal channel sensing threshold value that optimizes communication performance within a predetermined value interval of the channel sensing threshold value.

According to some embodiments of the present disclosure, the adjusting unit 703 may be further configured to adjust the current channel sensing threshold towards the optimal channel sensing threshold.

According to some embodiments of the present disclosure, the second determining unit 702 may be further configured to determine the optimal channel sensing threshold as the upper limit of the predetermined span if the communication performance is better at the upper limit than at the lower limit and better at the upper limit than at the left neighborhood of the upper limit. In these embodiments, the adjusting unit 703 may be further configured to increase the current channel sensing threshold by a first step.

According to some embodiments of the present disclosure, the second determining unit 702 may be further configured to determine that the optimal channel sensing threshold is between the upper limit and the lower limit of the predetermined span if the communication performance is better at the upper limit and better at the left-neighbor of the upper limit of the predetermined span, according to some embodiments of the present disclosure. In these embodiments, the adjusting unit 703 may be further configured to increase the current channel sensing threshold by a first step if the current channel sensing threshold is less than the optimal channel sensing threshold, and decrease the current channel sensing threshold by the first step if the current channel sensing threshold is greater than the optimal channel sensing threshold. According to some embodiments of the present disclosure, the optimal channel sensing threshold may be determined using a binary search method. Those skilled in the art will appreciate that binary search is only one exemplary method of numerical analysis methods for determining the optimal channel sensing threshold, and that other known suitable numerical analysis methods may be used to determine the optimal channel sensing threshold, and embodiments of the present disclosure are not limited in this respect.

According to some embodiments of the present disclosure, the second determining unit 702 may be further configured to determine the optimal channel sensing threshold as the lower limit of the predetermined span if the communication performance is better at the lower limit than at the upper limit and better at the lower limit than at the right neighborhood of the lower limit. In these embodiments, the adjusting unit 703 may be further configured to decrease the current channel sensing threshold by a first step size.

According to some embodiments of the present disclosure, the second determining unit 702 may be further configured to determine that the optimal channel sensing threshold is between the upper limit and the lower limit of the predetermined span if the communication performance is better at the lower limit and better at the right neighborhood of the lower limit of the predetermined span. In these embodiments, the adjusting unit 703 may be further configured to increase the current channel sensing threshold by a first step if the current channel sensing threshold is less than the optimal channel sensing threshold, and decrease the current channel sensing threshold by the first step if the current channel sensing threshold is greater than the optimal channel sensing threshold. According to some embodiments of the present disclosure, the optimal channel sensing threshold may be determined using a binary search method.

According to some embodiments of the present disclosure, the adjusting unit 703 may be further configured to stop adjusting the current channel sensing threshold when the communication performance is not lower than a predetermined level.

According to some embodiments of the present disclosure, the base station 700 may further include a transmitting unit 704. The transmitting unit 704 may be configured to transmit a request message to the neighboring base station to request the neighboring base station to adjust its channel sensing threshold.

According to some embodiments of the present disclosure, the base station 700 may further include a receiving unit 705. The receiving unit 705 may be configured to receive a notification message from the neighboring base station to notify the neighboring base station that its channel sensing threshold has been adjusted.

According to some embodiments of the present disclosure, the first determining unit 701 may be further configured to determine whether the communication performance is below the predetermined level in response to receiving the notification message.

According to some embodiments of the present disclosure, the transmitting unit 704 may be further configured to transmit the request message to the neighboring base station again if the communication performance is lower than the predetermined level; if the communication performance is not lower than the predetermined level, the transmission of the request message to the neighbor base station is stopped.

According to some embodiments of the present disclosure, the base station 700 may communicate with neighboring base stations using X2 signaling.

Fig. 8 schematically shows a block diagram of another base station 800 according to an embodiment of the present disclosure. In some embodiments of the present disclosure, the base station 800 may be configured to perform the method 500 described above with reference to fig. 5. As shown in fig. 8, the base station 800 may include a receiving unit 801, a determining unit 802, an adjusting unit 803, and a transmitting unit 804.

According to some embodiments of the present disclosure, the receiving unit 801 may be configured to receive a request message from a neighboring base station, the request message to request adjustment of a channel sensing threshold. The determining unit 802 may be configured to determine an optimal channel sensing threshold value that optimizes communication performance with respect to the channel sensing threshold value in response to the request message. The adjusting unit 803 may be configured to adjust the current channel sensing threshold based on the optimal channel sensing threshold while keeping the communication performance not below a predetermined level. The transmitting unit 804 may be configured to transmit a notification message to the neighboring base station to notify the neighboring base station that the channel sensing threshold has been adjusted.

According to some embodiments of the present disclosure, the determining unit 802 may be further configured to determine an optimal channel sensing threshold value that optimizes communication performance within a predetermined value interval of the channel sensing threshold value.

According to some embodiments of the present disclosure, the adjusting unit 803 may be further configured to adjust the current channel sensing threshold away from the optimal channel sensing threshold.

According to some embodiments of the present disclosure, the determining unit 802 may be further configured to determine the optimal channel sensing threshold as the upper limit of the predetermined span if the communication performance is better at the upper limit than at the lower limit and better at the upper limit than at the left neighborhood of the upper limit. In these embodiments, the adjusting unit 803 may be further configured to decrease the current channel sensing threshold by a second step size.

According to some embodiments of the present disclosure, the determining unit 802 may be further configured to determine that the optimal channel sensing threshold is between the upper limit and the lower limit of the predetermined span if the communication performance is better at the upper limit and better at the left-neighbor of the upper limit of the predetermined span. In these embodiments, the adjusting unit 803 may be further configured to decrease the current channel sensing threshold by a second step if the current channel sensing threshold is less than the optimal channel sensing threshold, and increase the current channel sensing threshold by the second step if the current channel sensing threshold is greater than the optimal channel sensing threshold. According to some embodiments of the present disclosure, the optimal channel sensing threshold may be determined using a binary search method. Those skilled in the art will appreciate that binary search is only one exemplary method of numerical analysis methods for determining the optimal channel sensing threshold, and that other known suitable numerical analysis methods may be used to determine the optimal channel sensing threshold, and embodiments of the present disclosure are not limited in this respect.

According to some embodiments of the present disclosure, the determining unit 802 may be further configured to determine the optimal channel sensing threshold as the lower limit of the predetermined span if the communication performance is better at the lower limit than at the upper limit and better at the lower limit than at the right neighborhood of the lower limit. In these embodiments, the adjusting unit 803 may be further configured to increase the current channel sensing threshold by a second step size.

According to some embodiments of the present disclosure, the determining unit 802 may be further configured to determine that the optimal channel sensing threshold is between the upper limit and the lower limit of the predetermined span if the communication performance is better at the lower limit and better at the right neighborhood of the lower limit of the predetermined span. In these embodiments, the adjusting unit 803 may be further configured to decrease the current channel sensing threshold by a second step if the current channel sensing threshold is less than the optimal channel sensing threshold, and increase the current channel sensing threshold by the second step if the current channel sensing threshold is greater than the optimal channel sensing threshold. According to some embodiments of the present disclosure, the optimal channel sensing threshold may be determined using a binary search method.

According to some embodiments of the present disclosure, the base station 800 may communicate with neighboring base stations using X2 signaling.

In describing embodiments of the present disclosure, the terms "include" and its derivatives should be interpreted as being open-ended, i.e., "including but not limited to. The term "based on" should be understood as "based at least in part on". The term "one embodiment" or "the embodiment" should be understood as "at least one embodiment".

It should be noted that the embodiments of the present disclosure can be realized by hardware, software, or a combination of software and hardware. The hardware portion may be implemented using dedicated logic; the software portions may be stored in a memory and executed by a suitable instruction execution system, such as a microprocessor or specially designed hardware. Those skilled in the art will appreciate that the apparatus and methods described above may be implemented using computer executable instructions and/or embodied in processor control code, such code being provided, for example, in programmable memory or on a data carrier such as an optical or electronic signal carrier.

Further, while the operations of the disclosed methods are depicted in the drawings in a particular order, this does not require or imply that these operations must be performed in this particular order, or that all of the illustrated operations must be performed, to achieve desirable results. Rather, the steps depicted in the flowcharts may change the order of execution. Additionally or alternatively, certain steps may be omitted, multiple steps combined into one step execution, and/or one step broken down into multiple step executions. It should also be noted that the features and functions of two or more devices according to the present disclosure may be embodied in one device. Conversely, the features and functions of one apparatus described above may be further divided into embodiments by a plurality of apparatuses.

While the present disclosure has been described with reference to several particular embodiments, it is to be understood that the disclosure is not limited to the particular embodiments disclosed. The disclosure is intended to cover various modifications and equivalent arrangements included within the spirit and scope of the appended claims.

Claims

1. A method of adjusting a channel sensing threshold, comprising:

determining that communication performance related to a channel sensing threshold is below a predetermined level;

determining an optimal channel listening threshold value that optimizes the communication performance;

adjusting a current channel sensing threshold based on the optimal channel sensing threshold; and

sending a request to a neighboring base station to adjust the listening threshold of the neighboring base station if the communication performance related to the channel listening threshold is still below the predetermined level after the adjusting.

2. The method of claim 1, wherein determining an optimal channel sensing threshold that optimizes the communication performance comprises:

and determining the optimal channel interception threshold value which enables the communication performance to be optimal within the preset value interval of the channel interception threshold value.

3. The method of claim 1, wherein adjusting a current channel sensing threshold based on the optimal channel sensing threshold comprises:

and adjusting the current channel interception threshold value towards the optimal channel interception threshold value.

4. The method of claim 2, wherein determining an optimal channel sensing threshold that optimizes the communication performance within a predetermined span of values of the channel sensing threshold comprises:

and if the communication performance is better than the lower limit at the upper limit of the preset value interval and is better than the left adjacent domain of the upper limit at the upper limit, determining that the optimal channel interception threshold is the upper limit of the preset value interval.

5. The method of claim 2, wherein determining an optimal channel sensing threshold that optimizes the communication performance within a predetermined span of values of the channel sensing threshold comprises:

and if the communication performance is better than the lower limit at the upper limit of the preset value range and better than the upper limit at the left adjacent domain of the upper limit, determining that the optimal channel listening threshold is between the upper limit and the lower limit of the preset value range.

6. The method of claim 2, wherein determining an optimal channel sensing threshold that optimizes the communication performance within a predetermined span of values of the channel sensing threshold comprises:

and if the communication performance is better at the upper limit at the lower limit of the preset value interval and better at the right neighborhood of the lower limit at the lower limit, determining that the optimal channel interception threshold is the lower limit of the preset value interval.

7. The method of claim 2, wherein determining an optimal channel sensing threshold that optimizes the communication performance within a predetermined span of values of the channel sensing threshold comprises:

and if the communication performance is better than the upper limit at the lower limit of the preset value range and better than the lower limit at the right neighborhood of the lower limit, determining that the optimal channel interception threshold is between the upper limit and the lower limit of the preset value range.

8. The method of claim 4, wherein adjusting a current channel sensing threshold based on the optimal channel sensing threshold comprises:

increasing the current channel sensing threshold by a first step size.

9. The method of claim 6, wherein adjusting a current channel sensing threshold based on the optimal channel sensing threshold comprises:

decreasing the current channel sensing threshold by a first step size.

10. The method of claim 5 or 7, wherein adjusting the current channel sensing threshold based on the optimal channel sensing threshold comprises:

if the current channel listening threshold is smaller than the optimal channel listening threshold, increasing the current channel listening threshold by a first step length; and if the current channel sensing threshold is greater than the optimal channel sensing threshold, decreasing the current channel sensing threshold by a first step size.

11. The method of claim 10, wherein the optimal channel sensing threshold is determined using a binary search method.

12. The method of claim 1, further comprising:

stopping adjusting the current channel sensing threshold when the communication performance is not below the predetermined level.

13. The method of claim 1, wherein when the current channel sensing threshold has been adjusted to the optimal channel sensing threshold and the communication performance is still below the predetermined level, the method further comprises:

sending a request message to the adjacent base station to request the adjacent base station to adjust the channel interception threshold value;

receiving a notification message from the neighboring base station to notify the neighboring base station that its channel sensing threshold has been adjusted;

determining whether the communication performance is below the predetermined level in response to receiving the notification message; and

if the communication performance is lower than the predetermined level, transmitting the request message to the neighboring base station again, and repeating the aforementioned transmitting step, receiving step, and determining step; and if the communication performance is not lower than the predetermined level, stopping transmitting the request message to the neighbor base station.

14. The method of claim 13, wherein X2 signaling is used to communicate with the neighboring base station.

15. The method of claim 1, wherein the communication performance comprises a short-time communication throughput.

16. The method of claim 1, wherein the method is performed semi-statically.

17. The method of claim 1, wherein the method is performed with the assistance of a user equipment.

18. A method of adjusting a channel sensing threshold, comprising:

receiving a request message from a neighboring base station, the request message requesting adjustment of a channel sensing threshold;

determining an optimum channel listening threshold value that optimizes communication performance with respect to a channel listening threshold value in response to the request message;

adjusting a current channel sensing threshold based on the optimal channel sensing threshold while maintaining the communication performance not below a predetermined level; and

sending a notification message to the neighboring base station to notify the neighboring base station that a channel sensing threshold has been adjusted.

19. The method of claim 18, wherein determining an optimal channel sensing threshold that optimizes the communication performance comprises:

20. The method of claim 18, wherein adjusting a current channel sensing threshold based on the optimal channel sensing threshold comprises:

and adjusting the current channel interception threshold value to be far away from the optimal channel interception threshold value.

21. The method of claim 19, wherein determining an optimal channel sensing threshold that optimizes the communication performance within a predetermined span of values of the channel sensing threshold comprises:

22. The method of claim 19, wherein determining an optimal channel sensing threshold that optimizes the communication performance within a predetermined span of values of the channel sensing threshold comprises:

23. The method of claim 19, wherein determining an optimal channel sensing threshold that optimizes the communication performance within a predetermined span of values of the channel sensing threshold comprises:

24. The method of claim 19, wherein determining an optimal channel sensing threshold that optimizes the communication performance within a predetermined span of values of the channel sensing threshold comprises:

25. The method of claim 21, wherein adjusting a current channel sensing threshold based on the optimal channel sensing threshold comprises:

decreasing the current channel sensing threshold by a second step size.

26. The method of claim 23, wherein adjusting a current channel sensing threshold based on the optimal channel sensing threshold comprises:

increasing the current channel sensing threshold by a second step size.

27. The method of claim 22 or 24, wherein adjusting a current channel sensing threshold based on the optimal channel sensing threshold comprises:

if the current channel interception threshold is smaller than the optimal channel interception threshold, reducing the current channel interception threshold by a second step; and increasing the current channel sensing threshold by a second step if the current channel sensing threshold is greater than the optimal channel sensing threshold.

28. The method of claim 27, wherein the optimal channel sensing threshold is determined using a binary search method.

29. The method of claim 18, wherein X2 signaling is used to communicate with the neighboring base station.

30. The method of claim 18, wherein the communication performance comprises a short-time communication throughput.

31. A base station, comprising:

a first determination unit configured to determine that communication performance related to a channel sensing threshold is lower than a predetermined level;

a second determination unit configured to determine an optimal channel listening threshold value that optimizes the communication performance; and

an adjusting unit configured to adjust a current channel sensing threshold based on the optimal channel sensing threshold,

wherein if after said adjusting, said communication performance related to said channel sensing threshold is still below said predetermined level, sending a request to a neighboring base station to adjust said sensing threshold of said neighboring base station.

32. A base station, comprising:

a receiving unit configured to receive a request message from a neighboring base station, the request message to request adjustment of a channel listening threshold;

a determination unit configured to determine, in response to the request message, an optimum channel listening threshold value that optimizes communication performance with respect to the channel listening threshold value;

an adjusting unit configured to adjust a current channel listening threshold based on the optimal channel listening threshold while keeping the communication performance not lower than a predetermined level; and

a transmitting unit configured to transmit a notification message to the neighboring base station to notify the neighboring base station that a channel sensing threshold has been adjusted.