CN106341902A

CN106341902A - Method and equipment for competing channel resources

Info

Publication number: CN106341902A
Application number: CN201510505856.9A
Authority: CN
Inventors: 李迎阳; 王轶; 孙程君
Original assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Current assignee: Beijing Samsung Telecommunications Technology Research Co Ltd; Samsung Electronics Co Ltd
Priority date: 2015-07-07
Filing date: 2015-08-17
Publication date: 2017-01-18

Abstract

The invention provides a method for competing channel resources. The method comprises the steps that: first equipment determines a parameter thereof for carrying out an LBT operation; ICCA is executed under the circumstance that a condition of executing an initial CCA (ICCA) is satisfied, that is, the first equipment occupies a channel as long as the first equipment detects that the channel is idle and set delay time BiCCA arrives; and the first equipment executes an extended CCA (ECCA) operation when the condition of executing the ICCA is not satisfied. The invention further provides corresponding equipment. According to the method and the equipment, technical schemes for processing the LBT under different circumstances are provided by the invention, and the effectiveness of channel competition of the LTE equipment is improved on the premise of ensuring fairness.

Description

Method and equipment for competing channel resources

Technical Field

The present invention relates to the field of wireless communications, and in particular, to a method and apparatus for contending for channel resources on an unlicensed frequency band in a Long Term Evolution (LTE) system.

Background

In a Long Term Evolution (LTE) system of the 3GPP standardization organization, downlink data is transmitted based on a hybrid automatic repeat request (HARQ) technology, and accordingly, a User Equipment (UE) needs to feed back HARQ-ACK information after receiving data from a base station, that is, ACK indicates successful reception of one Transport Block (TB) and NACK indicates failed reception of the TB. The HARQ-ACK information of the UE further includes Discontinuous Transmission (DTX), i.e. the UE does not receive downlink scheduling signaling (DL grant) of the base station, which may be that the base station does not schedule resources of the UE, or the UE does not receive the DL grant of the base station. According to the HARQ timing of the LTE system, for data transmission in a downlink subframe n, HARQ-ACK information of the data transmission is fed back in an uplink subframe n + k, and k is larger than or equal to 4. Specifically, for a cell of the FDD system, only HARQ-ACK information of data in one downlink subframe needs to be fed back in one uplink subframe. As shown in fig. 1, k is equal to 4 for FDD systems. For a cell of a TDD system, when downlink subframe data in a frame structure of the cell is more than uplink subframes, HARQ-ACK information of data in a plurality of downlink subframes generally needs to be fed back in one uplink subframe, and the plurality of downlink subframes are referred to as a bundling window corresponding to the uplink subframe. As shown in fig. 2, taking TDD uplink and downlink configuration 2 of a TDD system as an example, a bundling window includes 4 subframes, and k is greater than or equal to 4.

In the LTE system, a larger operating bandwidth is obtained by combining a plurality of Component Carriers (CCs), and a downlink and an uplink of the communication system are configured, that is, a Carrier Aggregation (CA) technique is employed, thereby supporting a higher transmission rate. Here, the aggregated CCs may use the same duplexing method, i.e., all FDD cells or all TDD cells, or may use different duplexing methods, i.e., both FDD cells and TDD cells exist. For a UE, a base station may configure it to operate in multiple cells, one of which is the primary Cell (pcell) and the others are referred to as secondary cells (scells). For the LTE CA system, hybrid automatic repeat request response (HARQ-ACK) and Channel State Information (CSI) transmitted based on a Physical Uplink Control Channel (PUCCH) are transmitted only on Pcell.

In order to meet the demand for an increase in mobile communication traffic for the LTE system, it is necessary to explore more spectrum resources. Deployment of LTE systems on unlicensed bands is one possible solution. Unlicensed frequency bands have typically been allocated for some other use, such as radar systems and/or 802.11 family wireless local area network (WiFi) systems. The 802.11 family of WiFi systems operate based on a carrier sense multiple access/collision avoidance (CSMA/CA) mechanism, in which a mobile Station (STA) must detect a radio channel before transmitting a signal, and can occupy the radio channel to transmit a signal only after the radio channel is idle and maintained for a certain period of time. The STA may jointly use two mechanisms to jointly determine the wireless channel status. In one aspect, the STA may actually detect the wireless channel using Carrier Sensing (Carrier Sensing), and when signals of other STAs are detected or the detected signal power exceeds a set threshold, confirm that the wireless channel is busy. At this time, the physical layer module in the STA reports a Clear Channel Assessment (CCA) report indicating that the radio Channel is busy to its higher layer module. On the other hand, the WiFi systems of the 802.11 series also introduce a virtual carrier sense technique, that is, a system allocation vector (NAV), which includes a duration field in each 802.11 frame, and confirms that a signal cannot be transmitted on a wireless channel according to a NAV value set in the duration field, where the NAV indicates a time required to reserve the wireless channel.

When an LTE system is deployed in an unlicensed frequency band, in order to avoid interference with other LTE devices or other wireless system devices, the LTE device needs to detect a state of a channel Before sending a signal, that is, Listen Before Talk (LBT), and the device can occupy the channel only when a channel occupancy condition is satisfied. Also, the channel occupancy time of a device may be one or more subframes, and then the channel must be released, leaving the opportunity for other devices to occupy the channel.

According to the european regulation (rule) on the unlicensed band, a device (LBE) performing LBT based on a load, a unit Time (TU) of CCA detection is at least 20us, the device performs CCA detection on a channel within one TU, and if the channel is found to be idle, the device may directly occupy the channel; if the channel is found to be busy, the device needs to start an extended CCA (ecca) procedure, that is, a number N is randomly generated and a counter for CCA detection is set, and then the counter may be decremented by one every time the device finds that the channel remains idle in one TU, if the device finds that the channel is busy, the counter remains unchanged, and when the counter is zeroed, the device may occupy the channel. Here, N is randomly chosen in the range of [1, q ], and the size q of the Contention Window (CW) ranges from 4 to 32. For an LBE device, when the channel occupancy condition is satisfied, the maximum length of time it can occupy the channel is equal to (13/32) · q. According to the discussion of LTE now, the size of the CW may be varied semi-statically or dynamically for friendly coexistence with other systems of unlicensed bands, such as WiFi. The HARQ timing of the LTE system and other characteristics bring certain limitations to the above-mentioned specific operations of LBT, and how to effectively design LBT of the LTE system is a problem to be solved.

Disclosure of Invention

The invention aims to provide a method and equipment for competing channel resources, so as to improve the effectiveness of LTE equipment in competing channels on the premise of ensuring fairness.

The method for contending for channel resources provided by the application comprises the following steps:

the first device determines parameters for performing listen before talk, LBT, operations;

in satisfyingIn a case where a condition of performing initial empty channel detection (ICCA) is satisfied, the first device performs ICCA in one channel of an unlicensed band, the performing ICCA including: as long as the first device detects that the channel is free and reaches the set delay time B_iCCAThe first device occupies the channel;

and when the condition for executing the ICCA is not satisfied, the first equipment executes an extended empty channel detection (ECCA) process in one channel of the unlicensed frequency band.

Preferably, for a carrier a of an unlicensed frequency band, the condition for performing ICCA includes any one or more of the following:

when the first device generates new data for any one of the second devices which have configured and activated the carrier a after the first device has not transmitted successful data to the second devices, the first device performs ICCA on the carrier a;

the first device does not schedule data transmission on the carrier A, but schedules data transmission on other carriers to the second device configured and activated with the carrier A, and then when the first device decides to reuse the carrier A for transmitting data, the first device executes ICCA on the carrier A;

when the ECCA process of the carrier a by the first device is completed, the first device does not schedule data transmission on the carrier a, but the first device schedules data transmission on a second device configured and activated with the carrier a on another carrier, and when the first device needs to transmit data by using the carrier a, the first device executes the ICCA on the carrier a;

when the ECCA process of the carrier a by the first device is completed, the first device does not schedule data transmission on any carrier to the second device configured and activated with the carrier a, and when the first device needs to transmit data by using the carrier a, the first device executes the ICCA on the carrier a;

when the first device configures at least one second device on carrier a, but all the second devices are in a deactivated state, the first device executes ICCA on carrier a when the at least one second device of carrier a is activated and data needs to be transmitted;

when an event causing that data transmission cannot be carried out occurs on the carrier A, after the event is finished, if the first equipment needs to transmit data on the carrier A, the first equipment executes ICCA on the carrier A;

after finishing channel occupation for one time on the carrier A, the first equipment still carries out data transmission on an occupied channel on at least one adjacent carrier, suspends the LBT operation on the carrier A, and executes ICCA on the carrier A when the adjacent carriers finish channel occupation;

the first device starts to occupy the channel on at least one adjacent carrier for data transmission before the ECCA process of the carrier A is completed, suspends the ECCA operation on the carrier A, and executes the ICCA on the carrier A when the adjacent carriers finish the channel occupation.

Preferably, the event causing the data transmission to be disabled includes any one or more of the following:

a time period during which the second device transmits a signal;

an idle period of time for the network configuration;

a measurement interval of the first device.

Preferably, the performing, by the first device, an ICCA procedure further includes:

when the first device detects that the channel is busy, the first device executes a new ECCA process; or, if there is a suspended ECCA procedure, the first device continues to perform the suspended ECCA procedure, otherwise, the first device performs a new ECCA procedure.

Preferably, for a carrier a of an unlicensed band, performing the ECCA procedure includes:

when the first device finishes the channel occupation for one time and data which is not transmitted exists, the first device starts a new ECCA process on the carrier A;

or, when the first device finishes one channel occupation, the data which is not transmitted still exists, and the set time T is_minWherein there is no event on carrier a that results in data transmission being disabled, the first device starts a new ECCA procedure on carrier a;

or after the first device finishes the channel occupation for one time, the first device starts a new ECCA process on the carrier a;

or, after the first device finishes the channel occupation for one time, if the first device finishes the channel occupation for a set time T_minIn the absence of the event on carrier a that results in the inability to transmit data, the first device starts a new ECCA procedure on carrier a;

or, when the event causing the data transmission incapability is ended, the first device starts a new ECCA process;

or after finishing channel occupation once, the first device suspends the LBT operation on the carrier a, assuming that the occupied channel is still on at least one adjacent carrier for data transmission, and starts a new ECCA procedure on the carrier a when the adjacent carriers all finish channel occupation.

Preferably, the method further comprises:

when the first device needs to transmit data by using the carrier A, if the ECCA process is completed, the first device executes ICCA; if the ECCA process is not completed, the first device continues the ECCA process;

or when the first device needs to transmit data by using the carrier A, the first device executes ICCA; when the channel is detected to be busy, the first equipment executes a new ECCA process; or, when the channel is detected to be busy, if there is a suspended ECCA procedure, the first device continues to perform said suspended ECCA procedure, otherwise, the first device performs a new ECCA procedure.

Preferably, if the first device starts to perform the ECCA procedure after finishing the channel occupation, and at the time T_minWherein the event causing the inability to perform data transmission occurs, the method further comprising:

if at T_minInternally completing an ECCA process, and if data needs to be transmitted on the carrier A after the event causing that the data transmission cannot be carried out is ended, executing ICCA by the first equipment;

if at T_minSuspending the ECCA process in the time period of the event causing the incapability of data transmission if the ECCA process is not completed, and continuing the suspended ECCA process by the first equipment after the event causing the incapability of data transmission is completed; or the first device executes ICCA, and when the channel is detected to be busy, the first device executes a new ECCA process; alternatively, the first device continues to perform the suspended ECCA procedure.

Preferably, for a carrier a of an unlicensed frequency band, the performing ECCA includes:

if the ECCA process is completed and the interval to the next time the event causing the data transmission failure is generated is greater than or equal to the set time T_dminIf yes, the first device occupies the channel; or if the interval to the next time the event causing the inability to perform data transmission occurs is less than T_dminWhen the event causing the incapability of data transmission is ended, the first equipment executes ICCA; or the first device suspends the ECCA process, and when the event causing the inability to perform data transmission is ended, the first device continues the LBT operation of the carrier a;

if the ECCA process is completed and the interval to the next time the event causing the data transmission failure is generated is greater than or equal to the set time T_dmin2If yes, the first device occupies the channel; if the ECCA process is still in progress, but the interval to the time of the above event is less than T_dmin2The first device suspends ECCA operation when said causesAfter the event that the data transmission cannot be carried out is finished, the first equipment continues the LBT operation of the carrier A;

before the ECCA procedure of the carrier a is completed, if the first device starts to occupy the channel on at least one adjacent carrier for data transmission, the first device suspends the ECCA procedure on the carrier a, and when all the adjacent carriers have finished occupying the channel, the first device continues LBT of the carrier a.

Preferably, the parameters for performing LBT operation include: a contention window CW;

for a carrier a of an unlicensed frequency band, performing ECCA includes: if the first device adjusts the CW if one ECCA procedure of the first device is in progress, the first device adjusts an ECCA status counter or timer of the ECCA procedure currently in progress accordingly according to the change of the CW.

Preferably, the adjusting the ECCA status counter or timer of the currently ongoing ECCA procedure includes:

if at the start of the ECCA process currently in progress, the value of CW is CW₀The corresponding generated target random number is N₀And assuming that the current adjusted CW size is CW_kThen adjust the target random number to N_k＝N₀·cw_k/cw₀；

If in the previous adjustment of the ECCA process currently in progress, the value of the corresponding CW is CW_k-1The corresponding generated target random number is N_kAnd assuming that the current adjusted CW size is CW_kThen adjust the target random number to N_k＝N_k-1·cw_k/cw_k-1。

Preferably, keeping in mind that up to now the first device has detected X clear CCA slots, said performing ECCA comprises:

if X is>＝N_kThe first device performs ICCA; otherwise, the first device continues to perform the ECCA procedure and upon detecting N_k-X number ofThe channel is occupied when the CCA slot is idle.

Preferably, the parameters for performing LBT operation include: CW;

for a carrier a of an unlicensed frequency band, performing ECCA includes: and determining the maximum channel occupation time according to the minimum value Cwmin of the CW variation range.

if at the start of the ECCA process currently in progress, the value of CW is CW₀And assuming that the CW size is currently adjusted to CW_kIf the ECCA state counter or the timer has a remainder value of n, the ECCA state counter or the timer is adjusted to have a remainder value of n ═ n · cw_k/cw₀(ii) a Or,

if the value of the corresponding CW is CW after the previous adjustment of the CW of the ECCA process currently in progress_k-1And assuming that the CW size is currently adjusted to CW_kIf the ECCA state counter or the timer has a remainder value of n, the ECCA state counter or the timer is adjusted to have a remainder value of n ═ n · cw_k/cw_k-1。

The application also discloses an apparatus, comprising: the device comprises a parameter determining module and a channel detecting module; wherein:

the parameter determining module is used for determining parameters for carrying out LBT operation;

the channel detection module executes ICCA under the condition that the condition of executing ICCA is met, wherein the executing ICCA comprises the following steps: as long as the channel is detected to be idle and the set delay time B is reached_iCCAThe device occupies the channel; and executing the ECCA process when the condition for executing the ICCA is not satisfied.

As can be seen from the foregoing technical solutions, according to the method and the device for contending for a channel resource provided by the present application, first, a first device determines a parameter for performing an LBT operation, and then, under a condition that an initial cca (ICCA) is performed, performs ICCA, that is, as long as the first device detects that a channel is idle and reaches a set delay time, the first device occupies the channel; the first device performs an extended cca (ecca) operation when a condition for performing ICCA is not satisfied. Moreover, the application further provides a technical scheme for processing the LBT under various different conditions, so that the validity of LTE equipment for channel competition is improved on the premise of guaranteeing fairness.

Drawings

FIG. 1 is a diagram of HARQ-ACK timing relationship for LTE FDD;

FIG. 2 is a diagram of HARQ-ACK timing relationship for LTE TDD;

FIG. 3 is a flowchart illustrating a method for contending for channel resources according to the present invention;

FIG. 4 is a diagram illustrating an ICCA handling an event that results in a failure to downlink in an embodiment of the present application;

FIG. 5 is a diagram illustrating ICCA handling an adjacent channel LBT operation according to an embodiment of the present invention;

FIG. 6 is a diagram illustrating a first example of handling new data transmission according to a second embodiment of the present application;

FIG. 7 is a second diagram illustrating handling of new data transmission according to a second embodiment of the present application;

fig. 8 is a diagram illustrating a first ECCA for handling an event causing downlink transmission incapability according to a second embodiment of the present invention;

fig. 9 is a schematic diagram of ECCA for processing an adjacent channel LBT operation according to the second embodiment of the present application;

fig. 10 is a diagram illustrating a second ECCA for handling an event causing a failure to downlink in the third embodiment of the present application;

fig. 11 is a schematic diagram of ECCA for processing an adjacent-channel LBT operation in the third embodiment of the present application;

fig. 12 is a schematic diagram of the adjusted CW of the 802.11 standard;

FIG. 13 is a schematic diagram of adjusting CW;

fig. 14 is a first schematic diagram illustrating adjusting CW in an LTE system according to a fourth embodiment of the present application;

fig. 15 is a schematic diagram of adjusting CW in an LTE system according to a fourth embodiment of the present application;

fig. 16 is a schematic structural diagram of a preferred apparatus of the present application.

Detailed Description

For the purpose of making the objects, technical means and advantages of the present application more apparent, the present application will be described in further detail with reference to the accompanying drawings.

When an LTE system is deployed on an unlicensed frequency band, in order to avoid interference with other LTE devices or other wireless system devices, the LTE device needs to detect a state of a channel, that is, LBT, before sending a signal, and only when a channel occupancy condition is satisfied, the device can occupy the channel. And after a device occupies a channel for a period of time, the channel occupation time cannot exceed the maximum occupation time, that is, the channel must be released, thereby leaving an opportunity for other devices to occupy the channel.

Fig. 3 shows a flowchart of a method for LTE device to contend for channel resources according to the present invention, which mainly includes:

step 301: the first device determines parameters for performing the LBT operation.

The parameters of the LBT operation may include a delay (defer) time, a size of a Contention Window (CW), a CCA slot length (slot), a maximum channel occupation time, and the like. The values of these parameters may be predefined or configured by other network nodes, or the first device may automatically adjust these values according to the operating state of the LTE system. The CW may be adjusted in size semi-statically or dynamically, for example, based on feedback from the second device or detection by the first device. In the following description of the present application, it is described by taking the first device as a base station and the second device as a UE as an example, and in fact, the technical solution provided in the present application may also be used when the first device is a UE and the second device is a base station. Compared with devices such as WiFi devices on an unlicensed operating band, the first device and the second device related to the present application may also be collectively referred to as LTE devices.

Step 302: performing initial cca (ICCA) if a condition for performing ICCA is satisfied, the performing ICCA comprising: whenever the first device detects that the channel is idle and reaches the set delay time, it is marked as B_iCCAThe first device may immediately occupy the channel.

For friendly coexistence with WiFi, B_iCCAMay be close to the delay time of WiFi, for example: close to the distribution coordination function interframe space (DIFS).

Step 303: when the condition for performing the ICCA is not satisfied, the first device performs an extended cca (ecca) procedure.

The first device continuously detects the channel. The first device reaches a set delay time (denoted as D) while the channel is idle each time the suspended ECCA procedure is restarted or continued_eCCA) Thereafter, the first device continues to detect the channel and updates the ECCA status each time it detects that the channel remains idle for one CCA slot length.

Here, if there is currently one ECCA procedure suspended, the first LTE device may continue this ECCA procedure; otherwise, a random number N is generated according to the current contention window parameter CW and used to restart the ECCA procedure. In some cases, the first LTE device may abort the ECCA procedure being suspended, i.e. restart the ECCA procedure.

Here, for friendly coexistence with WiFi, D_eCCAMay be close to the delay time of WiFi, for example: close to DIFS.

Several preferred methods of updating the ECCA status are described below, and the following methods are essentially equivalent:

1) setting an initial value of an ECCA counter to be N, and subtracting 1 from the ECCA counter when detecting that a channel keeps idle in one CCA time slot length each time; when the ECCA counter is zero, the LTE device may occupy the channel.

2) Setting an initial value of an ECCA counter to be 0, and adding 1 to the ECCA counter when a channel is detected to be idle in one CCA time slot length each time; when the ECCA counter reaches N, the LTE device may occupy the channel.

3) Recording the CCA time slot length as the slot, setting the initial value of the ECCA timer to be N.Slottime, and subtracting the slot from the ECCA timer when detecting that a channel is kept idle in one CCA time slot length each time; when the ECCA timer is zero, the LTE device may occupy the channel.

4) Setting an initial value of an ECCA timer to be 0, and adding a slot time to the ECCA timer when detecting that a channel keeps idle in one CCA time slot length each time; when the value of the ECCA timer reaches N · slot time, the LTE device may occupy the channel.

In the following five preferred embodiments, the method of the present invention is described based on an ECCA addition counter, and the described method can also be applied to other mechanisms for updating ECCA status.

Example one

ICCA may be performed under some conditions, as described above with respect to fig. 3. That is, the LTE device only needs to detect that the channel is idle and reaches the set delay time B_iCCAThen, the channel can be occupied for data transmission. By performing ICCA, LTE devices are allowed to quickly occupy the channel, reducing the time wasted by performing LBT operations. If the LTE device detects that the channel is busy, the LTE device performs a new ECCA process, namely, the LTE device generates a random number N according to the size of the current CW and sets an ECCA state counter or timer. Or, if the LTE device detects that the channel is busy, assume that there is one currentlyFor each suspended ECCA procedure, the LTE device may also continue to execute the suspended ECCA procedure; otherwise, the LTE device performs a new ECCA procedure.

An LTE device may perform ICCA in the following two cases. The first case is: the LTE device has no data to transmit, and when new data is generated at a later time, the LTE device may perform ICCA. The second case is: when the number of idle CCA slots detected in the ECCA process of the LTE device reaches N, the LTE device does not occupy the channel, and when data needs to be transmitted at a subsequent time, the LTE device may execute the ICCA. Here, in order to use the carrier of the unlicensed band, the UE generally operates in a CA mode, that is, the UE configures a plurality of carriers, and the carrier of the unlicensed band is configured as Scell.

For the first case, for one carrier a of an unlicensed frequency band, for any UE configured and activated with the carrier a, assuming that the base station has no data that has not been successfully transmitted to the UE, the base station may perform ICCA on the carrier a when new data is generated for any UE configured and activated with the carrier a at a subsequent time. Or, for the first case, the base station assumes that it decides not to schedule data transmission on one carrier a of the unlicensed band based on its scheduling policy, but the base station still schedules data transmission on the UE configured and activated with the carrier a on the carriers of other unlicensed bands or the carriers of the licensed band, and then the base station may perform ICCA on the carrier a when the base station decides to reuse the carrier a to transmit data at a subsequent time. Here, it may be further limited that the ICCA is performed only when the time when the base station gives up scheduling the carrier a reaches a set threshold value, for example, one subframe.

For the second case, for a carrier a in an unlicensed frequency band, when the number of idle CCA slots in the ECCA process reaches N, the base station does not schedule data transmission on the carrier a; however, the base station may still schedule data transmission on the UE configured and activated with the carrier a on the carrier of the other unlicensed frequency band or the carrier of the licensed frequency band, and then the base station may perform ICCA on the carrier a when the base station needs to transmit data using the carrier a at a subsequent time. Or, for the second case, for one carrier a in an unlicensed frequency band, when the number of idle CCA slots in the ECCA process reaches N, the base station does not schedule data transmission for the UE configured and activated with the carrier a on any carrier in the unlicensed frequency band or carrier in the licensed frequency band, and then the base station may execute ICCA on the carrier a when the base station needs to transmit data using the carrier a at a subsequent time.

In addition to the above two cases, the base station may perform ICCA in other cases.

Assuming that several UEs are configured on one carrier a of the unlicensed frequency band, but all UEs are currently in a deactivated state, when at least one UE of the carrier a is activated and data needs to be transmitted, the base station may perform ICCA on the carrier a. If there is an ECCA procedure currently in progress, this ECCA procedure is terminated. Here, while carrier a is inactive, the base station may be always scheduling data transmission to UEs that have configured carrier a with other carriers.

For a carrier of the unlicensed frequency band, the base station may not be able to perform downlink transmission in some cases. For example, the event that results in that downlink transmission cannot be performed may refer to an uplink transmission time period, that is, the base station needs to transition to a receiving state to receive uplink information of the UE. Or, the event causing that downlink transmission cannot be performed may refer to an idle time period configured by the network, that is, the base station does not schedule downlink data transmission in the idle time, but may detect a carrier wave of an unlicensed frequency band, including signals such as radar; when a radar signal is detected, the base station needs to interrupt the data transmission on this carrier wave to avoid interference to the radar. The idle time may be network-wide coordinated such that no LTE signal is present over such a period of time; alternatively, it may be possible to configure a part of the base stations, for example, neighboring base stations, with the same idle time, so as to reduce the signal level of the LTE system as much as possible. By configuring the idle time, the accuracy of detecting radar signals may be increased. Alternatively, the event causing that downlink transmission cannot be performed may refer to a measurement interval of the base station, that is, in the measurement interval, the base station stops downlink transmission of the current carrier and transfers the downlink transmission to an interference signal for measuring the current carrier, or measures interference signals of other carriers, for example, the base station may measure load conditions of the carriers, thereby determining whether the carriers are still suitable for LTE transmission. Here, if the interference of one carrier of the unlicensed band is too strong or the load is too heavy, the base station needs to avoid operating on this carrier; if the interference of the carrier currently operated by the base station is too strong or the load is too heavy, the base station can switch to operate on other carriers.

As shown in fig. 4, in response to the above events causing the inability of downlink transmission on one carrier a of the unlicensed frequency band, after the events causing the interruption of downlink transmission are ended, if the base station needs to transmit data on the carrier a, the base station may immediately perform ICCA. Here, assuming that the base station does not perform downlink transmission before the above event causing downlink transmission to be disabled occurs, the base station detects that the channel is idle and continues for B_iCCAThen, the time that the base station can occupy the channel is less than or equal to the maximum occupation time; or, because the event causing the downlink transmission incapability occurs, and the last channel occupation time of the base station does not reach the maximum channel occupation time, the base station detects that the channel is idle and continues to be B_iCCAThen, the time that the base station can occupy the channel can be determined by the following two methods: one method is to make the time that the base station occupies the channel less than or equal to the maximum occupied time, i.e. independent of the time that the channel has been occupied before the above event that results in the inability to perform downlink transmission occurs. Alternatively, another method is to assume that the time that the base station has transmitted before the above event causing the inability to perform downlink transmission occurs is T_BAnd recording the maximum occupation time as T_maxThen the time that the base station can occupy the channel is less than or equal to T_max-T_B. For the latter method, if the base station wants to continuously occupy the channel for a time longer than T after the end of the event causing the downlink transmission failure_max-T_BThe base station may re-perform the ECCA procedure.

Or, on a carrier a of the unlicensed frequency band, corresponding to the above events that cause the downlink transmission to be disabled, after the events that cause the downlink transmission to be interrupted are ended, if the base station has no unsent data and the previous ECCA procedure has ended, the base station may suspend LBT; if the base station has no unsent data but the previous ECCA procedure is not completed, the base station may continue the previous ECCA procedure.

As shown in fig. 5, for a carrier a of an unlicensed frequency band, after finishing downlink channel occupation once, assuming that one or more adjacent carriers (as shown, carrier X) still occupy the channel for downlink transmission, the base station may suspend LBT operation on the carrier a because there is large interference in simultaneous transceiving of adjacent carriers. When the adjacent carriers have finished the downlink channel occupation, the base station can immediately execute the ICCA procedure on the carrier a. Here, it may be further limited that the base station may perform the ECCA procedure on the carrier a only when the time for the suspended LBT of the carrier a due to the channel occupation of the neighboring carrier exceeds a threshold value, otherwise the base station performs the ECCA procedure. The threshold is either predefined or higher-level configured.

For one carrier a of one unlicensed band, it is assumed that the base station has already started to perform the ECCA procedure. Before the ECCA process of the carrier a is completed, it is assumed that the base station starts to occupy the channel on one or more adjacent carriers for downlink transmission. At this time, the base station may suspend ECCA operation on carrier a because there is large interference in simultaneous transceiving on adjacent carriers. When the neighboring carriers have finished downlink channel occupation, the base station may perform ICCA on carrier a. Here, it can be further limited that the base station can perform the ICCA procedure on carrier a only when the time for suspending ECCA of carrier a due to the channel occupation of the neighboring carrier exceeds a threshold value. The threshold is either predefined or higher-level configured.

Example two

Performing ICCA when not satisfied as described above with respect to FIG. 3On condition, the LTE device needs to perform the ECCA procedure. When a new ECCA process needs to be started, the base station generates a random number N according to the size of the current CW and sets an ECCA state counter or a timer; the base station starts to detect the channel, and when the base station detects that the channel is idle and reaches the set delay time D_eCCAThen, the base station continues to detect the channel, and updates an ECCA state counter or a timer when detecting that the channel is kept idle in one CCA time slot each time; when detecting that the N CCA slots satisfy the channel idle, the base station may occupy the channel to transmit data. According to the description of the first embodiment, for one carrier of the unlicensed frequency band, the base station may not perform downlink transmission in some cases. For example, the event that results in the inability to perform downlink transmission may refer to an uplink transmission time, an idle time, a measurement interval, and/or the like.

The first method for processing the ECCA process is that for a carrier A of an unlicensed frequency band, when a base station just finishes one-time downlink channel occupation and has downlink data which is not transmitted, the base station restarts the ECCA process on the carrier A; otherwise, if there is no downlink data not transmitted, the base station suspends LBT, i.e., does not perform ICCA and ECCA, and performs LBT on carrier a when new data is subsequently generated.

Or, the second method for processing the ECCA process is that, for a carrier a in an unlicensed frequency band, when the base station just finishes one downlink channel occupation, there is still downlink data that is not transmitted, and at a certain time T_minIn the absence of the above event on the carrier a, the base station immediately restarts the ECCA process on the carrier a; or if there is still downlink data not transmitted, but at T_minIf the event causing the downlink transmission incapability exists, the base station suspends the LBT, namely does not execute ICCA and ECCA, and can execute the ICCA process or restart the ECCA process on the carrier A until the event causing the downlink transmission incapability ends; or, if there is no untransmitted downlink data, the base station suspends LBT, i.e., does not perform ICCA and ECCA. Here, T_minIs predefined or higher layer signalingOf arrangement, T_minMay be a relatively short period of time during which the base station is not sufficient to complete channel preemption and transmit data.

For the first and second methods for handling ECCA, the existence of the untransmitted downlink data may mean that, for at least one UE configured and activated with the carrier a, the base station still has data that is unsuccessfully transmitted to the UE.

Or, the third method for processing the ECCA process is that, for a carrier a in an unlicensed frequency band, the base station immediately restarts the ECCA process on the carrier a after finishing one downlink channel occupation.

Or, the fourth method for processing the ECCA process is that, for a carrier a of an unlicensed frequency band, when the base station just finishes one downlink channel occupation, if the downlink channel occupation is finished within a certain time T_minIn the absence of the above event on the carrier a, the base station immediately restarts the ECCA process on the carrier a; otherwise, if at T_minIf the event causing that the downlink transmission can not be carried out exists in the system, the base station suspends the LBT, namely does not execute ICCA and ECCA, and after the event is ended, the base station restarts the ECCA process on the carrier A; alternatively, the base station may perform ICCA if the base station needs to transmit data on carrier a.

For the third and fourth methods for processing ECCA, even if the base station has not transmitted downlink data when ending channel occupation once, that is, for any UE configured and activated with carrier a, the base station has not transmitted successful data for the UE, the base station may still restart the ECCA process on carrier a immediately.

For the third and fourth methods for processing ECCA, when the base station finishes one downlink channel occupation, there is no downlink data that is not transmitted, but the base station still starts the ECCA process immediately. As shown in fig. 6, when the base station needs to transmit data by using the carrier a at a subsequent time, if the ECCA process is completed, the base station may directly perform the ICCA; if the ECCA process is not completedWhen this is done, the base station can directly continue the ECCA procedure until the ECCA procedure is completed and the channel is occupied. Or, when the base station needs to transmit data by using the carrier a at a subsequent time, if the ECCA process is not completed, the base station may directly continue the ECCA process until the ECCA process is completed and a channel is occupied; if this ECCA procedure has been completed, the base station needs to regenerate the random number N to restart the ECCA procedure. Alternatively, as shown in fig. 7, when the base station needs to transmit data using carrier a at a later time, the base station may perform ICCA. That is, the base station detects that the channel is idle for time duration B_iCCAThen, the base station can occupy the channel; if the channel is detected to be busy and the ECCA process is finished, the base station restarts the ECCA process; if the channel is detected to be busy and the ECCA procedure is not completed, the base station may directly continue the ECCA procedure until the ECCA procedure is completed and the channel is occupied.

Corresponding to the third and fourth methods for processing ECCA, an equivalent method is that, for a carrier a in an unlicensed band, when the base station just finishes one downlink channel occupation, assuming that there is no downlink data not transmitted by the base station, the base station may not generate the random number N, but the base station still starts to detect the channel, that is, when the base station detects that the channel is idle for a certain delay time D_eCCAAnd then, the base station continues to detect the channel, and records the total number of idle CCA time slots which are occupied by the time when the base station finishes the downlink channel to the current time when the channel is detected to be idle in one CCA time slot each time. Thus, when the base station needs to transmit data by using the carrier wave A at a certain subsequent moment, the base station generates a random number N according to the size of the current CW, and records that the total number of the idle CCA time slots which are occupied by the moment when the base station finishes the downlink channel to the current moment is X. If X is larger than or equal to N, the base station can directly execute ICCA; otherwise, the base station may set an ECCA status counter or timer so that the base station may occupy the channel when again discovering N-X clear CCA slots. Alternatively, when the base station needs to transmit data using carrier a at a later time, the base station may perform ICCA, i.e., the base station detects that the channel is idle and lasts for time B_iCCAThereafter, the base station may occupyA channel is used. If the channel is detected to be busy, the base station generates a random number N according to the size of the current CW, and records the total number of the idle CCA time slots from the time when the base station finishes occupying the downlink channel to the current time as X, and the base station can set an ECCA state counter or a timer according to X and N. For example, if X is less than N, the base station may set an ECCA status counter or timer so that the base station may occupy the channel when again discovering N-X clear CCA slots. If X is greater than or equal to N, the base station may set an ECCA status counter or timer with a random number N; or the base station may generate the random number N2 again according to the current CW size and set the ECCA status counter or timer; alternatively, the base station may also set an ECCA status counter or timer according to the current CW size, X and N, or N2, e.g., so that the base station may occupy the channel when again discovering N-XmodN clear CCA slots. For the ICCA, the base station detects that the channel is idle and lasts for a time B_iCCAThereafter, the base station may occupy the channel. B above_iCCAThe time may refer to a length B after time t when the base station needs to transmit data using carrier a_iCCAA period of time of (d); alternatively, if the base station is performing an ECCA procedure at time t and detects that the channel is idle, including at delay time D_eCCAWithin range, or within a clear CCA slot, the time at which the base station detected the channel gap before time t may also be calculated at B_iCCAWithin the time.

For the first and third methods for processing the ECCA procedure, it is assumed that the base station ends the downlink channel occupation for one time and then performs the ECCA procedure at the time T_minThe above-described event causing the downlink transmission to be disabled will occur. The base station starts to execute the ECCA process immediately after finishing one-time downlink channel occupation. As shown in fig. 8, even at T_minThe ECCA process is completed internally, but the base station still cannot be at T because of the above-mentioned event that results in the inability to downlink transmission_minAnd the base station can execute ICCA if data needs to be transmitted on the carrier A after the event is finished. If T is_minIf the inner ECCA process is not completed, the downlink transmission is not performed in the above-mentioned mannerIn the time period of the input event, the ECCA operation is suspended, and after the event is finished, the base station can continue the unfinished ECCA process. Alternatively, when the above event is over, if data needs to be transmitted on carrier a, the base station may also perform ICCA, i.e., the base station detects that the channel is idle and lasts for time B_iCCAThen, the base station can occupy the channel; if the channel is detected to be busy, the base station may start a new ECCA procedure or continue this unfinished ECCA procedure. T is_minCan be very short, providing only a certain guard time (GP). For example, in the uplink transmission, the GP provides the transceiving switching time of the base station and the UE, the CCA measurement time of the UE uplink transmission, and the subframe structure limitation.

A fifth method for handling the ECCA procedure is that the base station may start a new ECCA procedure immediately after the event causing the downlink transmission to be disabled is finished.

For different types of events that result in failure of downlink transmission, the same mechanism may be used to process LBT, or different methods may be used to process LBT.

Alternatively, during the time period of the event causing the downlink transmission to be disabled, since the base station is performing the receiving operation, it is possible to continue to detect whether the carrier a is idle. Thus, during the time period of the event causing the downlink transmission failure, the base station may continue to update the previous ECCA procedure, or the base station may start a new ECCA procedure.

A sixth method for handling the ECCA procedure is, as shown in fig. 9, after finishing downlink channel occupation for one carrier a of an unlicensed frequency band, assuming that one or more adjacent carriers (as shown, carrier X) still occupy the channel for downlink transmission, because there is large interference during simultaneous transceiving on the adjacent carriers, the base station may suspend the LBT operation on the carrier a. The base station can start a new ECCA procedure on carrier a only after the neighboring carriers have finished downlink channel occupation.

EXAMPLE III

According to the above description of fig. 3, the LTE device continuously detects the channel during the ECCA procedure performed by the LTE device. When the LTE equipment detects that the channel is idle for a certain delay time, which is recorded as D, every time the suspended ECCA process is restarted or continued_eCCAThereafter, the LTE device continues to detect the channel and updates the ECCA status counter or timer each time it detects that the channel remains idle for one CCA slot length. According to the description of the first embodiment, for one carrier of the unlicensed frequency band, the base station may not perform downlink transmission in some cases. For example, the event that results in the inability to perform downlink transmission may refer to an uplink transmission time, an idle time, a measurement interval, and/or the like.

It is assumed that the ECCA procedure may continue until the moment when the above-mentioned event leading to the inability to downlink is generated. As shown in fig. 10, it is assumed that the ECCA process has been completed and the interval to the next time the event causing the inability to perform downlink transmission is generated is equal to or greater than a certain time T_dminThe base station may occupy the channel. T is_dminMay be the minimum time that the base station occupies the channel. Alternatively, assume that the ECCA process has been completed and that the interval is less than T_dminThe base station cannot occupy the downlink channel; when the event causing the inability to perform downlink transmission ends, the base station may perform ICCA. Alternatively, assuming that the above-described event causing the inability to perform downlink transmission is generated before the ECCA procedure is ended, the base station may suspend the ECCA procedure from the time when the event is generated, i.e., without updating the ECCA status counter or timer. When the event causing the inability to downlink ends, the base station may continue the ECCA procedure of carrier a, which was previously suspended. Alternatively, the base station may also perform ICCA when the above event is over, i.e., the base station detects that the channel is idle and lasts for time B_iCCAThen, the base station can occupy the channel; if the channel is detected to be busy, the base station can directly continue the ECCA process, or can start a new ECCA process until the ECCA process is completed and the channel is occupied。

Alternatively, it is assumed that the ECCA process has been completed and the interval to the next time the event causing the inability to perform downlink transmission is generated is equal to or greater than a certain time T_dmin2The base station may occupy the channel. Alternatively, it is assumed that the ECCA process is still in progress, but the interval to the time of the above-described event that occurs has been less than T_dmin2Then the base station may suspend ECCA operation. When the event causing the inability to downlink ends, the previously suspended ECCA procedure for carrier a may continue. Alternatively, the base station may also perform ICCA when the above event is over, i.e., the base station detects that the channel is idle and lasts for time B_iCCAThen, the base station can occupy the channel; if the channel is detected to be busy, the base station may directly continue the ECCA procedure, or may start a new ECCA procedure until the ECCA procedure is completed and the channel is occupied.

Alternatively, during the time period of the event causing the downlink transmission to be disabled, since the base station is performing the receiving operation, it is possible to continue to detect whether the carrier a is idle. Thus, during the time period of the event causing the downlink transmission to be disabled, the base station can continue to update the previous ECCA procedure.

As shown in fig. 11, for one carrier a of one unlicensed band, it is assumed that the base station has already started to perform the ECCA procedure. Before the ECCA procedure for carrier a is completed, it is assumed that the base station starts to occupy the channel for downlink transmission on one or more adjacent carriers (as shown, carrier X). At this time, the base station may suspend ECCA operation on carrier a because there is large interference in simultaneous transceiving on adjacent carriers. When all the neighboring carriers have finished downlink channel occupation, the base station may continue the previously suspended ECCA procedure for carrier a. Alternatively, the base station may also perform ICCA, i.e., the base station detects that the channel is idle and lasts for time B_iCCAThen, the base station can occupy the channel; if the channel is detected to be busy, the base station may directly continue the ECCA procedure, or may start a new ECCA procedure until the ECCA procedure is completed and the channel is occupied.

For one carrier a of one unlicensed band, it is assumed that the base station has already started to perform the ECCA procedure. Before the ECCA process of the carrier a is completed, assuming that the base station has no downlink data that is not transmitted, the base station may continue to perform the ECCA process on the carrier a; alternatively, the base station may suspend ECCA operation on carrier a. Here, the reason why the base station does not have downlink data that is not transmitted may be that the base station completes data transmission to the UE using another carrier on which the UE is configured, or that the base station discards the UE data for another reason, such as timeout.

Example four

For the method of fig. 3 of the present invention, the CW of the LTE device may vary in size. For example, according to feedback from the UE or detection by the base station, the window of CW is changed exponentially, and the minimum value and the maximum value of the change range are denoted as CWmin and CWmax, respectively.

As shown in fig. 12, in the 802.11 system, after a device transmits one frame (frame, definition of frame of 802.11 is different from LTE), the device may start to detect the response message immediately, and adjust CW according to the situation of detecting the response message. For example, after the device sends a data frame, if no ACK frame is received, the CW size is doubled; if an ACK frame is received, it is possible for the device to reset the CW to its minimum value CWmin. Thus, the device can generate a random number N to contend for the channel according to the new CW size. The above timing relationship ensures that 802.11 devices adjust the CW in time according to their data transmission conditions and process subsequent contention channels with the new CW. However, in the LTE system, as shown in fig. 1 and fig. 2, after the base station transmits downlink data, HARQ-ACK feedback information of the UE needs at least 4ms to reach the base station, i.e. the base station of the existing LTE system can only use the HARQ-ACK information to adjust the CW after at least 4 ms.

Fig. 13 is a diagram of an LTE system adjusting CW. As shown in fig. 13, after finishing one channel occupation, the base station already starts a new ECCA process to contend for the channel before receiving the HARQ-ACK information of the UE for the downlink data a just transmitted. For example, the base station starts a new ECCA procedure immediately after finishing channel occupation once. When the time point when the base station starts a new ECCA procedure is t1, the base station generates a random number N according to the CW at the time point t1, and sets a state counter or timer of the new ECCA procedure. The CW at time t1 may be processed according to the HARQ-ACK information that has been received by the base station by time t1, but due to timing constraints, the CW at time t1 cannot be adjusted in the case of success or failure of downlink data a that has just been transmitted by the base station. When the base station receives the HARQ-ACK information for data a, the base station may adjust the CW according to these new HARQ-ACK information, but the base station does not change the ECCA state counter or timer for the ongoing ECCA procedure. By adopting the method, the base station can use the CW adjusted according to the HARQ-ACK information of the downlink data A only when the base station finishes the downlink transmission of the new data B and competes for the channel again after finishing the ECCA process which is currently carried out and occupying the channel to transmit the new data B. From the practical effect, the base station needs to wait for a relatively long time to compete for the channel based on the latest CW window, that is, the CW adjustment and application cannot timely reflect the transmission condition of the downlink data.

Based on the above analysis, the present invention proposes the following method to enable the treatment of the contention channel with the latest determined CW as soon as possible. Assuming that an ECCA process of a base station is in progress and the base station adjusts the CW according to some strategies, the present invention proposes that the base station can correspondingly adjust the ECCA status of the ECCA process currently in progress according to the change of the CW, for example, adjust a target random number, an ECCA status counter or a timer, etc., and continue to perform the ECCA process according to the ECCA status after the adjustment. Here, the reason why the base station adjusts the CW may be that the base station receives new HARQ-ACK information, or the base station detects a change in channel state by another method, or the like.

1) Alternatively, according to the change of CW, the base station may be an adjustment target random number that adjusts the ECCA procedure currently in progress, and adjust the ECCA status counter or timer accordingly. For example, as shown in fig. 14, when the base station receives HARQ-ACK information for data a, the base station may adjust CW according to these new HARQ-ACK information, and the base station may change the target random number of the ongoing ECCA procedure accordingly and adjust the ECCA status counter or timer accordingly, as compared to fig. 13. Therefore, as long as the number of the idle CCA time slots detected by the base station is more than or equal to the adjusted target random number, the base station can occupy the channel to transmit new data B.

For example, assume that at the start of the ECCA process currently in progress, the value of CW is CW₀The corresponding generated target random number is N₀And assuming that the CW size is currently adjusted to CW_kThen can be according to cw₀、N₀And cw_kAdjusting the target random number N_kE.g. N_k＝N₀·cw_k/cw₀. Alternatively, it is assumed that after the CW and the target random number of the ECCA process currently in progress are adjusted last time, the value of the corresponding CW is CW_k-1The corresponding target random number is N_k-1And assuming that the CW size is currently adjusted to CW_kThen can be according to cw_k-1、N_k-1And cw_kAdjusting the target random number N_kE.g. N_k＝N_k-1·cw_k/cw_k-1. Here, the above calculation yields N_kMay be adjusted to integers, such as rounded up.

After adjusting the target random number N_kAfter that, for the ECCA procedure currently in progress, keeping in mind that the base station has detected X clear CCA slots so far, then,

if X is>＝N_kThen the base station may perform ICCA. Specifically, the base station detects that the channel is idle for a time duration of B_iCCAThereafter, the base station may occupy the channel. B above_iCCATime may refer to adjusting a target random number from a base station to N_kIs B after the time t2_iCCAA period of time of (d); alternatively, if the base station is performing the ECCA procedure and detects that the channel is clear at time t2, including at delay time D_eCCAWithin the range, or with a delay time of D_eCCAWithin the next CCA slot, the time when the base station detected the channel gap before the time t2 may also be calculated at B_iCCAWithin the time. If the channel is detected to be busy, the base station may start a new ECCA procedure, i.e. the base station may again follow the current CW size CW_kTo generate a random number N' and set an ECCA status counter or timer; alternatively, the base station may start a new ECCA procedure, still with the random number N, the base station_kTo set an ECCA status counter or timer; alternatively, the base station may also be configured to determine the current CW size CW_kX and N' or N_kThe ECCA status counter or timer is set, e.g., such that the base station may occupy the channel when again discovering N '-XmodN' idle CCA slots.

Or, if X>＝N_kThe base station detects that the channel is idle for a time duration D_eCCAThereafter, the base station may occupy the channel. D above_eCCATime may refer to adjusting a target random number from a base station to N_kHas a length D after time t2_eCCAA period of time of (d); alternatively, if the base station is performing the ECCA procedure and detects that the channel is clear at time t2, assume that time t2 is at delay time D_eCCAWithin range, the base station detects that the channel is at delay time D_eCCAAfter the base station is kept idle, the base station can occupy the channel; suppose that time t2 is at delay time D_eCCAWithin the range of the next CCA slot, and the channel is still idle by t2, the base station may immediately occupy the channel; alternatively, assume that time t2 is at a delay time of D_eCCAIn the range of the next CCA slot, the base station may occupy the channel after detecting that the channel is clear in the current CCA slot. If the channel is detected to be busy, the base station may start a new ECCA procedure, i.e. the base station may again follow the current CW size CW_kTo generate a random number N' and set an ECCA status counter or timer;alternatively, the base station may start a new ECCA procedure, still with the random number N, the base station_kTo set an ECCA status counter or timer; alternatively, the base station may also be configured to determine the current CW size CW_kX and N' or N_kThe ECCA status counter or timer is set, e.g., such that the base station may occupy the channel when again discovering N '-XmodN' idle CCA slots.

If X is<N_kThe base station may continue to perform the ECCA procedure and only need to detect N_kThe channel may be occupied by X clear CCA slots.

2) Alternatively, the base station may adjust the ECCA status counter or timer according to the change of CW. For example, as shown in fig. 15, after the base station receives HARQ-ACK information of data a, the base station may adjust CW according to the new HARQ-ACK information, and the base station may change the ECCA state counter or the remaining value of the timer of the ongoing ECCA process accordingly, so that the base station continues to process the ECCA process according to the changed ECCA state counter or the remaining value of the timer, as compared to fig. 13. The ECCA status counter or timer described above is typically counted or timed in a subtraction.

For example, assume that at the start of the ECCA process currently in progress, the value of CW is CW₀And assuming that the CW size is currently adjusted to CW_kIf the remaining value of the ECCA state counter or timer is n, then the value can be based on cw₀And cw_kAdjusting the ECCA state counter or timer to keep the remaining value after adjustment as n', e.g., n ═ n · cw_k/cw₀. Alternatively, assume that after the CW of the ECCA process currently in progress is adjusted last, the value of the corresponding CW is CW_k-1And assuming that the CW size is currently adjusted to CW_kThen can be according to cw_k-1And cw_kAdjusting ECCA state counters or timers, e.g. n' ═ n · cw_k/cw_k-1. Here, when the ECCA status counter is used, the above calculated n' may be adjusted to an integer, for example, rounded up; when ECCA state counter is used, the above calculation to obtain n' may be calledThe whole is an integer multiple of the CCA slot length. Next, the base station may continue to process the ECCA procedure by the remaining value n' of the ECCA status counter or timer after the change.

EXAMPLE five

In the unlicensed frequency band, after the LTE device performs LBT operation and occupies the channel, the time for occupying the channel must be less than or equal to the maximum occupied time. The LTE device releases the channel and restarts the LBT procedure so that it can coexist with other devices. Here, the maximum occupation time of the device may be related to the size of a Contention Window (CW). According to the european regulation on the unlicensed band, keeping the size of CW as q, the value of q ranges from 4 to 32, the maximum time length that a device can occupy a channel is equal to T_max＝(13/32)·q。

For the method of fig. 3 of the present invention, the CW of the LTE device may vary in size. The size of the CW may be adjusted semi-statically or dynamically, e.g., based on feedback from the UE or detection by the base station. The case of semi-statically adjusting the CW may be to determine the maximum channel occupancy time from this semi-statically configured CW. For the case of dynamically adjusting CW, the maximum channel occupation time may be determined according to the minimum value CWmin of the CW variation range. Specifically, assuming that a window of CW is exponentially changed according to feedback from the UE or detection by the base station, and a minimum value and a maximum value of a change range thereof are denoted as CWmin and CWmax, respectively, the maximum channel occupation time may be determined according to the minimum value CWmin of the change range of CW.

Here, the formula stipulated in Europe may be employed to obtain the maximum channel occupancy time, T_maxWhere CW refers to the value of CW in a semi-static configuration or the minimum value CWmin of the dynamic range of CW. Alternatively, the above equation may be scaled when the CCA slot length Slottime is different from that specified in europe. E.g. T_maxCw Slottime/20 (13/32). Alternatively, other methods may be used to determine the maximum channel occupancy time based on cw, and the present inventionAnd are not intended to be limiting.

Corresponding to the above method, the present application also provides an apparatus, the constitution of which is shown in fig. 16, the apparatus comprising: the device comprises a parameter determining module and a channel detecting module; wherein:

The above description is only for the purpose of illustrating the preferred embodiments of the present invention and is not to be construed as limiting the invention, and any modifications, equivalents, improvements and the like made within the spirit and principle of the present invention should be included in the scope of the present invention.

Claims

1. A method for contending for channel resources, comprising:

the first device performs ICCA within one channel of an unlicensed band if a condition for performing initial empty channel detection (ICCA) is satisfied, the performing ICCA including: as long as the first device detects that the channel is free and reaches the set delay time B_iCCAThe first device occupies the channel;

2. The method of claim 1, wherein the ICCA is performed for a carrier a of an unlicensed frequency band under conditions including any one or more of:

3. The method of claim 2, wherein the event causing the inability to transmit data comprises any one or more of:

a time period during which the second device transmits a signal;

an idle period of time for the network configuration;

a measurement interval of the first device.

4. The method of claim 2, wherein the first device performing an ICCA procedure further comprises:

5. The method of claim 1, wherein performing the ECCA procedure for a carrier a in an unlicensed band comprises:

6. The method of claim 5, further comprising:

7. Method according to claim 5, wherein the ECCA procedure is started and executed at said time T if the first device ends a channel occupation_minWherein the event causing the inability to perform data transmission occurs, the method further comprising:

if at T_minCompleting ECCA process in-line when the result is that data cannot be processedAfter the transmitted event is finished, if data needs to be transmitted on the carrier A, the first equipment executes ICCA;

8. The method according to any of claims 2 to 5, wherein said performing ECCA for a carrier A of an unlicensed band comprises:

if the ECCA process is completed and the interval to the next time the event causing the data transmission failure is generated is greater than or equal to the set time T_dmin2If yes, the first device occupies the channel; if the ECCA process is still in progress, but the interval to the time of the above event is less than T_dmin2The first device suspends the ECCA operation, and when the event causing the data transmission incapability is ended, the first device continues the LBT operation of the carrier a;

9. The method according to any one of claims 1 to 7, wherein:

the parameters for performing LBT operations include: a contention window CW;

10. The method of claim 9, wherein adjusting the ECCA status counter or timer of the ECCA procedure currently in progress comprises:

if at the start of the ECCA process currently in progress, the value of CW is CW₀The corresponding generated target random number is N₀And assuming that the current adjusted CW size is CW_kThen adjust the target random number to N_k＝N₀·cw_k/cw₀(ii) a Or,

11. The method of claim 10, wherein noting that X number of clear CCA slots have been detected by the first device so far, the performing ECCA comprises:

if X is>＝N_kThe first device performs ICCA; otherwise, the first device continues to perform the ECCA procedure and upon detecting N_k-channel occupation for X clear CCA slots.

12. The method of claim 9, wherein adjusting the ECCA status counter or timer of the ECCA procedure currently in progress comprises:

13. The method according to any one of claims 1 to 7, wherein:

the parameters for performing LBT operations include: CW;

14. An apparatus, comprising: the device comprises a parameter determining module and a channel detecting module; wherein: