KR20160011131A - Device and method for outbound detection - Google Patents

Abstract

A macro cell user terminal of the present invention comprises: a cellular communications module, a wireless LAN communications module, a memory storing a program for detecting an outbound with a small cell base station, and a processor for executing the program. The processor includes: setting a wireless LAN link; detecting an outbound based on a connection status of the set wireless LAN link; and transferring an outbound report to any one of a connected macro cell base station and a connected small cell base station when the outbound of the small cell base station is detected, when the terminal is adjacent to the small cell base station after the macro cell base station is connected through a cellular link by executing the program.

Description

[0001] DEVICE AND METHOD FOR OUTBOUND DETECTION [0002]

The present invention relates to a terminal and method for detecting outbound.

Recently, in the 3GPP (Third Generation Partnership Project), cellular-wireless LAN interworking, small cell base station enhancement technology, dual connectivity technology, and cellular-wireless LAN And discussions and standardization of wireless level integration technologies are actively underway.

In particular, in an environment in which a small cell base station and a macro cell base station coexist, the cellular-wireless LAN integrated technology can effectively control mutual interference, distribute traffic by wireless LAN communication, and control the access efficiency of the terminal. However, if interference between heterogeneous cells in the same frequency resource is very large in this process, the UE may enter the dead zone and coverage hole, and it may be difficult to maintain a connection with a specific base station.

Resource partitioning techniques are used to overcome this. The resource partitioning scheme is a method for resolving interference between heterogeneous cells by preventing radio resource collision between adjacent cells by dividing a specific radio resource, and is effective when the mobile station receives or receives interference in the coverage of the corresponding small cell.

In particular, in a cellular network in which low-power transmission small cells coexist, in order to distribute the traffic of the macro cell base station to the small cell base station, the terminal performing communication with the macro cell base station searches for the neighboring small cell base station, Can be performed. Through the handover to the small cell base station, the mobile station must reduce the load of the macro cell base station and provide the traffic dispersion effect. However, the handover of the terminal to the small cell base station can be limited due to the limited coverage of the transmission power of the small cell base station.

Therefore, a cell range expansion (CRE) scheme can be applied in 3GPP LTE to efficiently perform handover to a small cell base station of a mobile station. In this technique, a specific bias is added to the signal of the small cell base station so that the MS recognizes the signal of the small cell base station more strongly than the signal of the existing macro cell base station, thereby enlarging the handover area to the small cell base station.

In order to protect the signal of the small cell base station in the area where the cell area extending technique is applied, the MS can perform resource partitioning by using only a small cell base station without using a part of the radio resources of the macro cell base station.

However, the resource partitioning technique has a disadvantage in that the efficiency of radio resources can be significantly lowered by dividing and utilizing radio resources. Also, in the case of a small cell base station using the resource partitioning technique, since the radio resources can be allocated for non-member user terminals that do not have access rights, resource efficiency may be seriously degraded.

Therefore, in order to effectively utilize resource partitioning, outbound detection is required to determine whether the UE exists in an interference area of a small cell base station environment or out of the area.

As a conventional technique for effectively controlling mutual interference in an environment where a small cell base station and a macro cell base station coexist, Korean Unexamined Patent Application Publication No. 10-2014-0020684 entitled " Control method and apparatus for use of heterogeneous networks considered) discloses a method capable of improving network performance and user experience service quality by securing radio resources capable of sending data to a user using a wireless LAN communication network in cellular communication .

Korean Patent Laid-Open No. 10-2014-0042775 (entitled " LTE-WIFI coexistence ") establishes a cellular link and a wireless LAN link in a device in which a cellular communication module and a wireless LAN communication module coexist, Discloses a technique for performing data communication based on a wireless LAN for an interval. This technology can distribute traffic of data communication because it utilizes both cellular link and wireless LAN link for data communication simultaneously.

It is an object of the present invention to provide a terminal and method for detecting an outbound in a small cell base station based on a wireless LAN link.

It should be understood, however, that the technical scope of the present invention is not limited to the above-described technical problems, and other technical problems may exist.

As a technical means for achieving the above technical object, a first aspect of the present invention includes a cellular communication module, a wireless LAN communication module, a memory for storing a program for detecting an outbound with a small cell base station, and a processor for executing a program do. At this time, the processor establishes a wireless LAN link when the terminal is adjacent to the small cell base station after the connection to the macro cell base station via the cellular link according to the execution of the program, And when an outbound to the small cell base station is detected, the outbound report is transmitted to at least one of the connected macro cell base station and the small cell base station.

According to a second aspect of the present invention, there is provided a method for establishing a wireless LAN link with a small cell base station, the method comprising the steps of: establishing a wireless LAN link with the small cell base station when the terminal connected to the macro cell base station via the cellular link is adjacent to the small cell base station; Detecting an outbound based on a connection state of a set wireless LAN link; And delivering the outbound report to at least one of the connected macro cell base station and the small cell base station when outbound to the small cell base station is detected.

According to any one of the above-mentioned problems, the present invention has an effect of improving radio resource efficiency by an outbound detection terminal and a technique effective for a resource division technique for interference control in a small-cell base station supporting a cellular and a wireless LAN . In addition, the present invention can control the interference based on the wireless LAN link with the small cell base station when the terminal receives strong interference from the neighboring small cell base station. Therefore, the present invention has an effect of dispersing the traffic of the small cell base station and supporting the organic interworking between the cellular and the wireless LAN.

In addition, the present invention supports interworking between cellular and wireless LANs, enabling continuous wireless communication services and distributing network load.

1 is an exemplary diagram for explaining resource allocation between a macro cell base station and a small cell base station in the absence of outbound detection.
2 is an exemplary diagram for explaining an outbound detection method based on a conventional cellular link.
3 is an exemplary diagram for explaining an outbound detection method based on a wireless LAN link according to an embodiment of the present invention.
4 is a flowchart illustrating an outbound detection method based on a WLAN link according to an embodiment of the present invention.
5 is a block diagram illustrating a macro cell user terminal according to an embodiment of the present invention.
6 is a flowchart illustrating an outbound detection method of a macro cell user terminal according to an embodiment of the present invention.
7 is a flowchart illustrating a method of transmitting an outbound report to a macro cell BS according to an exemplary embodiment of the present invention.
8 is a flowchart illustrating a method of transmitting an outbound report to a small cell base station according to an exemplary embodiment of the present invention.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings, which will be readily apparent to those skilled in the art. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In order to clearly explain the present invention in the drawings, parts not related to the description are omitted.

Throughout the specification, when a part is referred to as being "connected" to another part, it includes not only "directly connected" but also "electrically connected" with another part in between . Also, when a part is referred to as "including " an element, it does not exclude other elements unless specifically stated otherwise.

The outbound detection method in a cellular network according to an embodiment of the present invention will now be described with reference to Figs.

1 is an exemplary diagram for explaining resource allocation between a macro-cell BS 100 and a small-cell BS 110 in the absence of outbound detection.

1, when the macro cell user terminal 120 having no access right to the small cell base station 110 is located in the vicinity of the small cell base station 110, the macro cell user terminal 120 transmits, Due to the strong interference of the base station 110, falls into dead zones and coverage holes where communication is impossible.

In order to overcome such a problem, the macro cell base station 100 and the small cell base station 110 perform resource partitioning to mute a specific portion of resources and set them as blank subframes, Only a part of the macrocell user terminal 120 can be allocated. In addition, the small cell base station 110 can allow the macro cell user terminal 120 to communicate with the macro cell base station 100 without causing interference with low power.

In this manner, when the division of the radio resources is used, the interference source can be directly removed, and the effect of mitigating or eliminating the interference can be clarified. However, since the macro cell user terminal 120 that is not a member of the small cell base station 110 does not use radio resources reserved in the small cell base station 110 as shown in (1) of FIG. 1, The radio resources reserved for the terminal 120 can be maintained in the blank subframe state, and the efficiency of resource utilization can be remarkably lowered.

Therefore, the macro cell user terminal 120 should check frequently whether the small cell base station 110 is experiencing interference or not in the coverage of the small cell base station 110 for the quick recovery of unused resources. The macro cell base station 100 and the small cell base station 110 may be configured for the macro cell user terminal 120 for resource efficiency immediately after the macro cell user terminal 120 is out of interference with the small cell base station 110 You must release the allocated resources quickly.

If the macro cell user terminal 120 is out of the coverage of the small cell base station 110 and the outbound detection is not performed quickly, the small cell base station 110 transmits the macro cell user terminal 120 allocated for the macro cell user terminal 120 The resource can not be released. Therefore, the member user 200 having the access right to the small cell base station 110 can not utilize the resources allocated for the macro cell user terminal 120 that is not actually used. Therefore, the small cell base station 110 is inefficient in resource efficiency, which may degrade performance.

In addition, since the macro cell base station 100 and the macro cell user terminal 120 use only the resources allocated through the resource partitioning in the macro cell base station 100, they can not acquire additional resource utilization opportunities and unnecessary scheduling overhead Can be increased.

That is, in order to utilize the resources of the macro cell base station 100 and the small cell base station 110 smoothly, the macro cell user terminal 120, through the outbound detection, either interferes within the coverage of the small cell base station 110 You should check back often to see if you have escaped.

The outbound detection method of the macro cell user terminal 120 based on the existing cellular link is shown in FIG.

2 is an exemplary diagram for explaining an outbound detection method based on a conventional cellular link.

Referring to FIG. 2, the macro cell user terminal 120 communicates with the macro cell base station 100 through a cellular link. In addition, the small cell user terminal 200 capable of connecting the small cell base station 110 can perform communication via the cellular link of the small cell base station 110.

In this case, when the macro cell user terminal 120 enters the coverage of the small cell base station 110, the macro cell base station 100 and the small cell base station 110 perform resource partitioning Resource allocation.

The macro cell user terminal 120 performs data communication with the macro cell base station 100 through the cellular link, and at the same time periodically or occasionally out of the macro cell user terminal 120 through the cellular link to check whether interference occurs in the coverage of the small cell base station 110 Bound detection. That is, the macrocell user terminal 120 must retrieve and measure two cellular links, which are periodically or periodically independent of each other, and perform data communication. Therefore, the macro cell user terminal 120 may not be able to perform data communication with the macro cell base station 100 during the process.

When the macro cell user terminal 120 detects the outbound through the cellular link, the macro cell user terminal 120 sends an outbound report (hereinafter referred to as an " outbound report ") to the macro cell base station 100 in an indirect manner outbound report. The macro cell base station 100 receives the outbound report to the macro cell user terminal 120 and then delivers the outbound report to the small cell base station 110 based on the back bone network.

Therefore, in the existing outbound detection method, the overhead that the small cell base station 110 receives information on outbound detection from the macro cell user terminal 120 increases, and the time required for releasing the allocated resources increases It can be long.

An outbound detection method according to an embodiment of the present invention to overcome this problem will be described with reference to FIG.

3 is an exemplary diagram for explaining an outbound detection method based on a wireless LAN link according to an embodiment of the present invention.

In the outbound detection method based on the WLAN link according to an embodiment of the present invention, the macro cell user terminal 120 detects outbound based on a wireless LAN link with the small cell base station 300 in which the wireless LAN is integrated .

As shown in FIG. 3, the outbound detection method based on the WLAN link can be performed independently of the cellular link with the macro cell base station 100. Therefore, if this method is used, the macrocell user terminal 120 can omit additional search and measurement via the cellular link in the existing method, and can transmit the outbound report based on the cellular link and the wireless LAN link, It is possible to construct a cellular network environment with the macro cell base station 100 which is stable and stable.

In addition, the macro cell user terminal 120 can notify the small cell base station 300 of the outbound detection through the wireless LAN link without going through the macro cell base station 100 as soon as outbound is detected. Therefore, the small cell base station 300 releases resources allocated to the macro cell user terminal 120 without delay immediately after receiving the outbound report through the wireless LAN link.

The following describes the outbound detection method based on the WLAN link in the cellular network system in detail using FIG.

4 is a flowchart illustrating an outbound detection method based on a WLAN link according to an embodiment of the present invention. Please change '310' to '300' in the drawing.

4, a cellular network system according to an exemplary embodiment of the present invention includes a macro cell base station 100, a macro cell user terminal 120, a small cell base station 300, and a small cell user terminal 200 .

The cellular network includes, but is not limited to, a 3rd Generation Partnership Project (3GPP) network, a Long Term Evolution (LTE) network, and a Long Term Evolution Advanced (LTE)

The macro cell base station 100 is a base station having high transmission power and wide coverage. In addition, the small cell base station 300 is a small base station having low transmission power and narrow coverage, unlike the macro cell base station 100 having a high transmission power and a wide coverage. At this time, the small cell base station 300 may include a small power base station equipment, a femto cell, a micro cell, and a pico cell.

Herein, a base station generally refers to a station that communicates with a wireless device and may also be referred to as another term such as an evolved-NodeB (eNB), a base transceiver system (BTS), and an access point.

In addition, the macro cell user terminal 120 and the small cell user terminal 200 may be fixed or mobile. For example, the macro cell user terminal 120 and the small cell user terminal 200 may be a wireless communication device that is guaranteed to be portable and mobility, that is, a PCS (Personal Communication System), a GSM (Global System for Mobile communications) A handheld based wireless communication device such as a cellular phone, a digital cellular phone, a PHS (Personal Handyphone System), a PDA (Personal Digital Assistant), a Wibro (Wireless Broadband Internet)

The macro cell user terminal 120 and the small cell user terminal 200 may be a general computer such as a server, a workstation, a desktop computer and a notebook computer and a smartphone, , And smart devices such as tablet PCs.

Meanwhile, when the macro cell user terminal 120 communicating with the macro cell base station 100 in the cellular network system enters the coverage of the small cell base station 300, strong interference is received from the small cell base station 300 (S400) .

At this time, the macro cell base station 100 requests the small cell base station 300 to perform resource partitioning setup to overcome the strong interference of the small cell base station 300 (S410). At this time, resource partitioning means to mute or release part of the resource.

When the resource partitioning is performed, the macro cell base station 100 and the small cell base station 300 allocate the resources P400 and P410 including the blank sub-frame to the macro cell user terminal 120 and the small cell user terminal 200 (S420).

The macro cell base station 100 requests activation of the wireless LAN link to the macro cell user terminal 120 and the small cell base station 300 at the time or period when resource partitioning is performed at step S430. The macro cell user terminal 120 and the small cell base station 300 having received the activation request for the wireless LAN link activate the wireless LAN link between the macro cell user terminal 120 and the small cell base station 300 at step S440, . Then, the macro cell user terminal 120 monitors the outbound based on the connection state of the wireless LAN link (S450).

At this time, the connection state of the wireless LAN link can be measured using the communication signal strength of the wireless LAN link of the small cell base station 300 measured by the macro cell user terminal 120. [ The communication signal strength of the wireless LAN link can be measured by the wireless LAN communication module included in the macro cell user terminal 120.

And the communication signal strength of the predetermined wireless LAN link may be a value set based on the communication signal strength of the measured wireless LAN link when the small cell base station 300 is connected. The macro cell user terminal 120 periodically compares the intensity of the communication signal of the currently measured wireless LAN link with the intensity of the communication signal of the predetermined wireless LAN link. The macro cell user terminal 120 can detect the outbound when the communication signal strength of the currently measured WLAN link is lower than the communication signal strength of the predetermined WLAN link as a result of the comparison.

In addition, the connection state of the WLAN link may be determined by a macrocell user terminal 120 receiving a beacon frame periodically transmitted by the small cell base station 300, or receiving a beacon frame transmitted from a wireless LAN transmission frame The included preamble can be monitored to detect outbound. For example, the macro cell user terminal 120 can detect an outbound when the small cell base station 300 can not receive the beacon frame or the preamble transmitted through the wireless LAN link.

The connection state of the wireless LAN link is determined based on a probe request and a probe response used by the macro cell user terminal 120 to search for the wireless LAN of the small cell base station 300 Can be detected. Specifically, in order to activate the wireless LAN link of the small cell base station 300, the macro cell user terminal 120 transmits a probe response to the small cell base station 300 through the probe request transmission to the small cell base station 300 Can be requested. In this method, the macro cell user terminal 120 which transmitted the probe request receives the probe response from the small cell base station 300, monitors the signal quality of the wireless LAN of the small cell base station 300, Outbound can be detected based on quality.

The macro cell user terminal 120 can perform cellular communication with the macro cell base station 100 based on the cellular link with the macro cell base station 100 to which the macro cell user terminal 120 has been connected even after the wireless LAN link is established. In addition, the small cell user terminal 200 performs communication with the small cell base station 300 through the cellular link with the small cell base station 300 that has already been connected.

The macro cell user terminal 120 may transmit an outbound report to the macro cell base station 100 through the cellular link when the outbound is detected in the small cell base station 300 in operation S460, . In addition, the macro cell user terminal 120 may transmit the outbound report to the small cell base station 300 through the wireless LAN link (S480).

At this time, if the macrocell user terminal 120 can not transmit the outbound report to the macro cell base station 100 or the small cell base station 300 due to a broken link or an abnormality in either the cellular link or the wireless LAN link The macro cell base station 100 and the small cell base station 300 can receive the outbound report through the connected backbone network, respectively.

For example, when the macrocell base station 100 fails to receive an outbound report directly from the macrocell user terminal 120 due to a broken cellular link or an error, And can receive the outbound report transmitted from the small cell base station 300 through the network.

Similarly, when the small cell base station 300 fails to receive the outbound report directly from the macro cell user terminal 120, the small cell base station 300 transmits the outbound report to the macro cell user terminal 120, And can receive the outbound report transmitted from the macro cell base station 100 through the network.

After receiving the outbound report from the macro cell user terminal 120, the macro cell base station 100 and the small cell base station 300 release resources allocated at the time of resource partitioning (S490) (P440, P450) to the small cell user terminal (120) and the small cell user terminal (200).

5, a macrocell user terminal 120 according to an embodiment of the present invention will be described.

FIG. 5 is a diagram illustrating a macrocell user terminal 120 according to an embodiment of the present invention.

The macrocell user terminal 120 according to an exemplary embodiment of the present invention includes a cellular communication module 500, a wireless LAN communication module 510, a memory 520, and a processor 530.

At this time, the memory 520 stores a program for detecting the outbound with the small cell base station 300. [ For example, the memory 520 may be a compact flash (CF) card, a secure digital (SD) card, a memory stick, a solid- A magnetic computer storage device such as a NAND flash memory, a hard disk drive (HDD) and the like, and an optical disc drive such as a CD-ROM, a DVD-ROM, etc. .

On the other hand, the processor 530 generates a cellular link with the macro cell base station 100 based on the cellular communication module 500 according to the execution of the program, and performs cellular data communication through the generated cellular link.

When the macro cell user terminal 120 is adjacent to the small cell base station 300 after being connected to the macro cell base station 100, the macro cell user terminal 120 may receive strong interference from the small cell base station 300. At this time, the processor 530 establishes a wireless LAN link with the small cell base station 300 through the wireless LAN module 510. The processor 530 then detects the outbound based on the established connection status of the wireless LAN link.

Here, the connection state of the wireless LAN link may be measured using the communication signal strength of the wireless LAN link measured by the processor 530 through the wireless LAN communication module 510. For example, the processor 530 may measure the communication signal strength of the measured WLAN link based on the WLAN communication module 510. [

And the processor can be detected outbound if the communication signal strength of the measured WLAN link is below a predetermined threshold. At this time, the communication signal strength of the predetermined wireless LAN link may be a value set based on the communication signal strength of the measured wireless LAN link when the processor 530 connects to the small cell base station 300.

In addition, the processor 530 can detect the outbound by receiving a beacon periodically or periodically transmitted by the small cell base station 120 through the wireless LAN link or by monitoring the preambles transmitted and received by the small cell base station 120.

When an outbound to the small cell base station 300 is detected, the processor 530 delivers the outbound report to at least one of the connected macro cell base station 100 and the small cell base station 300.

The processor 530 may utilize a cellular link with the macro cell base station 100 to deliver the outbound report to the macro cell base station 100. The processor 530 may also utilize a wireless LAN link with the small cell base station 300 to deliver the outbound report to the small cell base station 300.

At this time, the processor 530 may not be able to deliver the outbound report to the macro cell base station 100 or the small cell base station 300 due to a broken link or a link between the cellular link and the wireless LAN link. In this case, the macro cell base station 100 and the small cell base station 300 can receive the outbound report through the connected backbone network, respectively.

For example, when the macro cell base station 100 fails to receive the outbound report because the cellular link is broken or an error occurs, the macro cell base station 100 transmits the outbound report transmitted from the small cell base station 300 Can be received through the backbone network. When the small cell base station 300 fails to receive the outbound report due to the disconnection of the wireless LAN link or the occurrence of an anomaly, the small cell base station 300 transmits the outbound report transmitted from the macro cell base station 100 Can be received through the backbone network.

Next, an outbound detection method of the macro cell user terminal 120 according to an embodiment of the present invention will be described with reference to FIGS. 6 to 8. FIG.

6 is a flowchart illustrating an outbound detection method of the macro cell user terminal 120 according to an embodiment of the present invention.

When the macro cell user terminal 120 is connected to the macro cell base station 100 via the cellular link and is adjacent to the small cell base station 300 in operation S600, And establishes a wireless LAN link with the small cell base station through the base station 510 (S610). Here, the criterion for determining that the macro cell user terminal 120 is adjacent to the small cell base station 300 may vary. For example, when the macro cell user terminal 120 is geographically close to the small cell base station 300 and / or when the signal strength from the small cell base station 300 is higher than a certain standard.

The macro cell user terminal 120 checks the connection state of the wireless LAN link of the periodically connected small cell base station 300 and detects outbound based on the connection state in operation S620.

For example, the macrocell user terminal 120 can detect an outbound if the communication signal strength of the wireless LAN link is less than or equal to a preset threshold value. In addition, the macro cell user terminal 120 can detect the outbound by receiving the beacon periodically transmitted by the small cell base station 300 or by monitoring the preamble. The connection state of the wireless LAN link can be detected based on the probe request and the probe response used by the macro cell user terminal 120 to search for the wireless LAN of the small cell base station 300. [

Meanwhile, when an outbound connection with the small cell base station 300 is detected, the macro cell user terminal 120 delivers the outbound report to at least one of the connected macro cell base station 100 and the connected small cell base station 300 S630). At this time, the method of delivering the outbound report will be described with reference to FIG. 7 and FIG.

7 is a flowchart illustrating a method of transmitting an outbound report to a macrocell base station 100 according to an exemplary embodiment of the present invention. 8 is a flowchart illustrating a method of transmitting an outbound report to a small cell base station 300 according to an exemplary embodiment of the present invention.

After detecting the outbound, the macro cell user terminal 120 can forward the outbound report to the macro cell base station 100 through the cellular link (S700). The macro cell base station 100 receiving the outbound report can release the radio resources of the macro cell base station 100 allocated for the macro cell user terminal 120 (S710).

In addition, the macro cell user terminal 120 may detect the outbound and then forward the outbound report to the small cell base station 300 through the wireless LAN link (S800). The small cell base station 300 receiving the outbound report can release the radio resources of the small cell base station 300 allocated for the macro cell user terminal 210 in operation S810.

When the outbound is detected, the macro cell user terminal 120 transmits an outbound report to the macro cell base station 100 through the cellular link and transmits an outbound report to the small cell base station 300 through the wireless LAN link Lt; / RTI >

The outbound detection terminal 120 and method according to an embodiment of the present invention is an outbound detection technique effective for a resource partitioning technique for interference control in a small cell base station 300 supporting cellular and wireless LAN, There is an effect of improving the efficiency. In addition, the outbound detection terminal 120 and method can control the interference based on the wireless LAN link with the small cell base station 300 when receiving strong interference from the neighboring small cell base station 300. [ Therefore, the outbound detection terminal 120 and method are effective to distribute the traffic of the small cell base station 300 and to support the organic interworking between the cellular and the wireless LAN.

In addition, the outbound detection terminal 120 and method support interworking between cellular and wireless LANs, enabling continuous wireless communication services and distributing network load.

One embodiment of the present invention may also be embodied in the form of a recording medium including instructions executable by a computer, such as program modules, being executed by a computer. Computer readable media can be any available media that can be accessed by a computer and includes both volatile and nonvolatile media, removable and non-removable media. In addition, the computer-readable medium may include both computer storage media and communication media. Computer storage media includes both volatile and nonvolatile, removable and non-removable media implemented in any method or technology for storage of information such as computer readable instructions, data structures, program modules or other data. Communication media typically includes any information delivery media, including computer readable instructions, data structures, program modules, or other data in a modulated data signal such as a carrier wave, or other transport mechanism.

While the methods and systems of the present invention have been described in connection with specific embodiments, some or all of those elements or operations may be implemented using a computer system having a general purpose hardware architecture.

It will be understood by those skilled in the art that the foregoing description of the present invention is for illustrative purposes only and that those of ordinary skill in the art can readily understand that various changes and modifications may be made without departing from the spirit or essential characteristics of the present invention. will be. It is therefore to be understood that the above-described embodiments are illustrative in all aspects and not restrictive. For example, each component described as a single entity may be distributed and implemented, and components described as being distributed may also be implemented in a combined form.

The scope of the present invention is defined by the appended claims rather than the detailed description and all changes or modifications derived from the meaning and scope of the claims and their equivalents are to be construed as being included within the scope of the present invention do.

100: macro cell base station 110: small cell base station
120: Macrocell user terminal 200: Small cell user terminal
300: Small cell base station 500 with integrated wireless LAN 500: Cellular communication module
510: Wireless LAN communication module 520: Memory
530: Processor

Claims (13)

In a macrocell user terminal,
Cellular communication module,
Wireless LAN communication module,
A memory for storing a program for detecting an outbound to a small cell base station,
And a processor for executing the program,
The processor, upon execution of the program,
When the terminal is adjacent to the small cell base station after being connected to the macro cell base station via the cellular link,
Wherein the mobile terminal establishes a wireless LAN link with the small cell base station through the wireless LAN communication module, detects an outbound based on a connection state of the established wireless LAN link,
And transmits an outbound report to at least one of the connected macro cell base station and the small cell base station when an outbound connection with the small cell base station is detected. The method according to claim 1,
Wherein the processor detects outbound when the communication signal strength of the set wireless LAN link is less than or equal to a preset threshold value. 3. The method of claim 2,
Wherein the predetermined threshold value is set based on a measured communication signal strength of the wireless LAN link when connecting to the small cell base station. The method according to claim 1,
Wherein the processor detects the outbound upon receipt of a beacon periodically transmitted by the small cell base station via the wireless LAN link. The method according to claim 1,
Wherein the processor monitors the preamble transmitted and received via the wireless LAN link to detect the outbound. The method according to claim 1,
Wherein the processor forwards the outbound report to the macrocell base station via the cellular link. The method according to claim 1,
Wherein the processor forwards the outbound report to the small cell base station via the wireless LAN link. A method for detecting an outbound of a macrocell user terminal,
When the terminal connected to the macro cell base station through the cellular link is adjacent to the small cell base station,
Establishing a wireless LAN link with the small cell base station;
Detecting an outbound based on a connection state of the set wireless LAN link; And
Transmitting an outbound report to at least one of the connected macro cell base station and the small cell base station when an outbound to the small cell base station is detected. 9. The method of claim 8,
Wherein the detecting the outbound comprises:
And when the communication signal strength of the wireless LAN link is equal to or less than a predetermined threshold value, the outbound detection is performed. 9. The method of claim 8,
Wherein the detecting the outbound comprises:
And detecting the outbound upon receipt of the beacon periodically transmitted by the small cell base station via the wireless LAN link. 9. The method of claim 8,
Wherein the detecting the outbound comprises:
And detecting the outbound by monitoring a preamble transmitted and received via the wireless LAN link. 9. The method of claim 8,
Wherein the step of delivering the outbound report comprises:
Transmitting the outbound report to the macro cell base station through a cellular link of the terminal; And
And releasing the radio resources of the macro cell base station allocated to the terminal by the macro cell receiving the outbound report. 9. The method of claim 8,
Wherein the step of delivering the outbound report comprises:
Transmitting the outbound report to the small cell base station via a wireless LAN link of the terminal;
And releasing the radio resources of the small cell base station allocated to the mobile station by the small cell base station that has received the outbound report.

Images