KR20220043079A - method and system for adaptively supporting a wireless connection to a femtocell base station - Google Patents

Abstract

The present invention relates to a method for adaptively supporting a wireless connection to a femtocell base station and a system thereof. A mobile station is located in both a coverage area of a current base station and a coverage area of another base station, in particular, a femtocell base station. The mobile station has an access permission to the current base station, but does not have an access permission to an external base station. A limited connection is permitted between the mobile station and the external base station. One embodiment of the present invention is to improve a method of a firstly described type of supporting an operational wireless connection between the mobile station and a macrocell or femtocell base station in a manner that adopts a mechanism for smoothly performing a reduction in interference of the mobile station in an area of a wireless network system.

Description

A method and system for adaptively supporting a wireless connection to a femtocell base station and a system thereof

The present invention relates to a method and system for adaptively supporting a wireless connection to a femtocell base station.

From mobile network operators to deploying so-called femtocells (also known as home base stations, home BTSs, picocells, home NBs, femto access points (FAPs), or femto radio base stations) that are currently installed in the operator's customer's home. interest exists. Femtocells developed and standardized for these current 3G or 4G networks are low-cost mobile base stations scaled down to low transmission power. The installation of a femtocell base station will generally be done without any technical training by the consumers themselves, therefore it should be a simple plug-and-play procedure. A femtocell base station is similar to a WiFi access point, but the radio interface is based on wide area cellular network standards such as Worldwide Interoperability for Microwave Access (WiMAX), Universal Mobile Telecommunications System (UMTS) or 3GPP Long Term Evolution (LTE). Femtocell base stations are connected to the operator's network through a virtual private network connection on a normal broadband Internet connection (backhaul connection) such as DSL or Fiber to the home (FTTH).

One reason for the adoption of femtocells is the increase in operator network area and a big leap forward towards wired and wireless convergence along with a better user experience. Like Wi-Fi access points, femtocells are supposed to be deployed in home or office environments to provide full coverage in each area, and high-density deployments are expected in areas with high population or office density. However, the deployment of femtocells introduces the drawback of interference effects between the macro and femto level of the network. Because femtocell base stations are often deployed on the same licensed spectrum as the operator's wide area network, it is important to configure the radio interface correctly to avoid interference from other base stations.

Femtocell networks can improve indoor coverage and capacity. However, a femtocell base station needs to carefully balance its transmit power, which must be high enough to ensure good reception strength for its subscribers, but is too high to coexist with other mobile stations and macro base stations with other femtocells. should not cause serious interference with To deal with this problem, according to prior art solutions, for example, a femtocell is connected to a Radio Resource Management (RRM) of the network, which is a functional/logical unit generally located in the radio access network and it It controls allocation and transmission power.

In addition, the owner of the backhaul connection and/or the femtocell base station will want to limit access to the femtocell base station as he has to pay the maintenance and cost of the broadband connection on his premises. For example, a Closed Subscriber Group (CSG) femtocell base station (referred to as CSG-Closed) is defined in IEEE 802.16m, and, with the exception of emergency services, only mobile stations that are members of this base station Accessible. The problem in this case is that a mobile station that is within the coverage area of a femtocell base station but is not a member of this femtocell will experience strong interference and may not be able to maintain an authenticated connection with its macrocell base station or femtocell base station. In the worst case scenario, the interference will be so severe that access to the network will be completely blocked for the affected mobile station. The network will not have any information as to the cause of the lack of connectivity of the affected mobile station and cannot take corrective action to reconnect the mobile station.

Domestic Registered Patent No. 10-2318642 (2021.1.22) US Patent Publication US 2010-0111035 A1 (2010.05.06) Japanese Patent Laid-Open Patent JP 2012-170013 A (2012.09.06)

It is an object of the present invention to provide a method and a system for adaptively supporting a wireless connection to a femtocell base station.

In addition, an embodiment of the present invention supports an operational wireless connection between a mobile station and a macrocell or femtocell base station in a manner that smoothly adopts a mechanism for smoothly reducing the interference of the mobile station in the area of the wireless network system. The purpose is to improve the method.

The technical problems to be achieved in the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those of ordinary skill in the art to which the present invention belongs from the description below. will be able

The present invention proposes a method and system for adaptively supporting a wireless connection to a femtocell base station.

The present invention contemplates that a mobile station located within the coverage area of a foreign base station and not having access to the foreign base station is subject to and/or causes strong interference from and/or to the foreign base station. In this regard, it is recognized for the first time that, according to the present invention, a mobile station that does not have an access grant needs special attention by an external base station. In particular, it is recognized that interference can be reduced by allowing limited connections between mobile stations and external base stations. The restricted connection may be used to inform the mobile station of the interference it receives and/or causes. Appropriate measures will then be induced to mitigate or avoid interference soon. Thus, the mobile station is not excluded from the network and an important improvement in mobile station connectivity is achieved because of it. Restricted connectivity provides mobile stations that do not have access grants the opportunity/means to start the process of accessing the wireless network using very little radio resources of external base stations and attempting to mitigate interference. Both current base stations and external base stations may be used to provide mobile stations with access to the mobile operator's network and its services. Due to this, the method according to the present invention increases the quality of service (QoS) of the mobile station when it enters the coverage area of the foreign base station.

The method according to the present invention can be suitably applied to, for example, cellular technologies such as UMTS and WiMAX. However, the present invention relates to any radio access network with access control, such as various types of mesh networks or ad-hoc networks, as well as other radio systems such as Digital Enhanced Cordless Telecommunications (DECT) or IEEE 802.11 compliant systems. It should be understood that this is applicable.

According to a preferred embodiment, restricted connections may be granted to a mobile station when it registers itself with an external base station. Thus, when an active mobile station without an access grant is in the coverage area of a foreign base station, it can qualify as a mobile station that is not a member and register itself with the foreign base station to grant this restricted access. For example, a mobile station that is not a member may register itself with an external base station under certain conditions, such as when the mobile station is under severe interference from an external base station.

According to a preferred embodiment, the restricted connection may be implemented in such a way that only transmission (transmission and/or reception) of signaling information is permitted. This means that limited connections cannot be used for transmission (transmission and/or reception) of traffic data for non-member mobile stations. This provides for a mobile station experiencing severe interference conditions to communicate with the network via an external base station and communicate information about its signal conditions to reduce interference.

In particular, the signaling information allowed to be transmitted over the restricted connection will be used to inform the operator's network of radio conditions in the vicinity of the mobile station.

An embodiment of the present invention may provide a method and a system for adaptively supporting a wireless connection to an enhanced femtocell base station.

The effects obtainable in the present invention are not limited to the above-mentioned effects, and other effects not mentioned may be clearly understood by those of ordinary skill in the art to which the present invention belongs from the following description. will be.

Other aspects, features and benefits as set forth above of certain preferred embodiments of the invention will become more apparent from the following description taken in conjunction with the accompanying drawings.
1 is a schematic diagram illustrating an example of an application scenario of a method according to the present invention;
2 is a schematic diagram of an example of another application scenario of the method according to the invention, showing two femtocells with overlapping coverage areas;
3 is a schematic diagram of an example of another application scenario of the method according to the invention, showing a macro cell and a number of femtocells with overlapping coverage areas;
It should be noted that throughout the drawings, like reference numerals are used to denote the same or similar elements, features, and structures.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings.

In describing the embodiments, descriptions of technical contents that are well known in the technical field to which the present invention pertains and are not directly related to the present invention will be omitted. This is to more clearly convey the gist of the present invention without obscuring the gist of the present invention by omitting unnecessary description.

For the same reason, some components are exaggerated, omitted, or schematically illustrated in the accompanying drawings. In addition, the size of each component does not fully reflect the actual size. In each figure, the same or corresponding elements are assigned the same reference numerals.

Advantages and features of the present invention, and a method for achieving them will become apparent with reference to the embodiments described below in detail in conjunction with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms, and only these embodiments allow the disclosure of the present invention to be complete, and common knowledge in the technical field to which the present invention belongs It is provided to fully inform the possessor of the scope of the invention, and the present invention is only defined by the scope of the claims. Like reference numerals refer to like elements throughout.

At this time, it will be understood that each block of the flowchart diagrams and combinations of the flowchart diagrams may be performed by computer program instructions. These computer program instructions may be embodied in a processor of a general purpose computer, special purpose computer, or other programmable data processing equipment, such that the instructions performed by the processor of the computer or other programmable data processing equipment are not described in the flowchart block(s). It creates a means to perform functions. These computer program instructions may also be stored in a computer-usable or computer-readable memory that may direct a computer or other programmable data processing equipment to implement a function in a particular manner, and thus the computer-usable or computer-readable memory. It is also possible that the instructions stored in the flow chart block(s) produce an article of manufacture containing instruction means for performing the function described in the flowchart block(s). The computer program instructions may also be mounted on a computer or other programmable data processing equipment, such that a series of operational steps are performed on the computer or other programmable data processing equipment to create a computer-executed process to create a computer or other programmable data processing equipment. It is also possible that instructions for performing the processing equipment provide steps for performing the functions described in the flowchart block(s).

Additionally, each block may represent a module, segment, or portion of code that includes one or more executable instructions for executing specified logical function(s). It should also be noted that in some alternative implementations it is also possible for the functions recited in blocks to occur out of order. For example, two blocks shown one after another may be performed substantially simultaneously, or the blocks may sometimes be performed in the reverse order according to a corresponding function.

In this case, the term '~ unit' used in this embodiment means software or hardware components such as field-programmable gate array (FPGA) or ASIC (Application Specific Integrated Circuit), and '~ unit' refers to what role carry out the However, '-part' is not limited to software or hardware. '~' may be configured to reside on an addressable storage medium or may be configured to refresh one or more processors. Accordingly, as an example, '~' indicates components such as software components, object-oriented software components, class components, and task components, and processes, functions, properties, and procedures. , subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays, and variables. The functions provided in the components and '~ units' may be combined into a smaller number of components and '~ units' or further separated into additional components and '~ units'. In addition, components and '~ units' may be implemented to play one or more CPUs in a device or secure multimedia card.

In describing embodiments of the present invention in detail, an example of a specific system will be mainly targeted, but the main subject matter to be claimed in the present specification is to extend the scope disclosed herein to other communication systems and services having a similar technical background. It can be applied within a range that does not deviate significantly, and this will be possible at the discretion of a person with technical knowledge skilled in the art.

1 is a schematic diagram illustrating an application scenario in the context of a cellular network; In the illustrated embodiment, a femtocell base station (hereinafter referred to as a femto BS) is installed in an indoor environment. The coverage area of the femto BS is represented by an elliptic curve in an ideal form. Both the mobile station having access permission to the femto BS (member MS a) and the mobile station not having access permission to the femto BS (non-member MS b) are located in the coverage area of the femto BS.

In the embodiment shown in Figure 1, it is assumed that the Femto BS operates using the concept of a Closed Subscriber Group (CSG) that allows only members to access its services.

Based on this, the femto BS maintains two lists; One is the member list, which contains all members of the closed subscriber group of the Femto BS; And the other is a non-member list that includes active mobile stations that are not members of the femto BS and are located in the coverage area of the femto BS.

Member MS a as a member of the closed subscriber group has full access to the femto BS, whereas the non-member MS b (initially) has no access to the femto BS. However, the non-member MS b has full access to a macro cell base station (macro BS), which is currently referred to as a macro cell base station, and wants to maintain a guaranteed connection with the macro BS.

Once the non-member MS b is in the coverage area of the femto BS and its status is Active, it registers itself with the femto BS as a non-member according to its access right and is included in the non-member list of the femto BS. . When included in the non-member list, the non-member MS b is allowed limited access and connection of the femto BS. This restricted connection is used to transmit (transmit and/or receive) signaling information for interference mitigation purposes. However, a restricted connection is established in such a way that it cannot be used to transmit or receive any traffic data by the non-member MS b. The signaling information includes, for example, channel state information, the spectral resources used by the mobile station, the power level of the received interference, and the like.

For downlink transmission, the femto BS may use interference mitigation techniques that are allowed to transmit over the restricted connection and reduce interference to the non-member MS b based on the signaling information provided by the non-member MS b. These techniques may include advanced antenna systems such as beamforming, power control, spectrum avoidance, and the like.

For uplink transmission, this information may be used by the femto BS to cancel interference from the non-member MS b. The femto BS may also inform the macro BS and/or non-member MS b about its spare resource not used by the femto BS, so that the unused resource can be allocated to the non-member MS b without significant interference. there is. The femto BS will also negotiate with the macro BS base station of the non-member MS b on the allocation of resources to optimize overall network performance.

2 is a schematic diagram illustrating an application scenario with two femtocell base stations (femto BS A and femto BS B) overlapping the coverage area of the femto base station. Two femtocell base stations manage their own member lists and non-member lists, respectively. Mobile station femto A member a is a member of femto BS A and a non-member of femto BS B. Conversely, mobile station femto B member b is a member of femto BS B and a non-member of femto BS A. Furthermore, both the mobile station femto A member a and the femto B member b are located within the coverage areas of the femto BS A and the femto BS B. Interference caused by the overlap of the two femtocells is reduced by allowing limited connectivity to each external femtocell base station for both mobile stations. Therefore, the performance of a femtocell is improved when the coverage areas of independent femtocell base stations overlap because a mobile station that is a member of one femtocell base station will be in the non-member list of another femtocell base station and because of that, the interference between these two femtocell base stations is reduced. will decrease

3 shows a schematic diagram of an example of an application scenario in which a macro cell and three femtocell base stations have overlapping coverage areas. The mode of operation of the method according to the invention is similar to the embodiments described in connection with FIGS. 1 and 2 . 3 additionally shows that one mobile station will be included in the non-member list of several femtocells because the coverage area of the femtocells will have overlap.

The embodiments of the present invention disclosed in the present specification and drawings are merely provided for specific examples in order to easily explain the technical contents of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. That is, it will be apparent to those of ordinary skill in the art to which the present invention pertains that other modifications can be implemented based on the technical idea of the present invention. In addition, each of the above embodiments may be operated in combination with each other as needed. For example, all embodiments of the present invention may be implemented by a system, server and/or terminal of the present invention in combination with each other in parts.

In addition, the method of controlling the system, server and/or terminal of the present invention may be implemented in the form of program instructions that can be executed through various computer means and recorded in a computer-readable medium.

As such, various embodiments of the present invention may be embodied as computer readable code on a computer readable recording medium in a particular aspect. A computer readable recording medium is any data storage device capable of storing data that can be read by a computer system. Examples of computer readable recording media include read only memory (ROM), random access memory (RAM), and compact disk-read only memory (CD-ROM). ), magnetic tapes, floppy disks, optical data storage devices, and carrier waves (such as data transmission over the Internet). The computer readable recording medium may also be distributed over network coupled computer systems, so that the computer readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for achieving various embodiments of the present invention may be easily interpreted by programmers skilled in the field to which the present invention is applied.

In addition, it will be appreciated that the apparatus and method according to various embodiments of the present invention can be realized in the form of hardware, software, or a combination of hardware and software. Such software may include, for example, a volatile or non-volatile storage device, such as a ROM, or a memory, such as, for example, RAM, a memory chip, device or integrated circuit, whether erasable or rewritable, or For example, the storage medium may be stored in an optically or magnetically recordable storage medium such as a compact disk (CD), a DVD, a magnetic disk, or a magnetic tape, and a machine (eg, computer) readable storage medium. The method according to various embodiments of the present invention may be implemented by a computer or portable terminal including a control unit and a memory, and the memory is to store a program or programs including instructions for implementing the embodiments of the present invention. It will be appreciated that this is an example of a suitable machine-readable storage medium.

Accordingly, the present invention includes a program including code for implementing the apparatus or method described in the claims of the present specification, and a machine (computer, etc.) readable storage medium storing such a program. Also, such a program may be transmitted electronically through any medium such as a communication signal transmitted through a wired or wireless connection, and the present invention suitably includes the equivalent thereof.

The embodiments of the present invention disclosed in the present specification and drawings are merely provided for specific examples to easily explain the technical content of the present invention and help the understanding of the present invention, and are not intended to limit the scope of the present invention. In addition, the above-described embodiments according to the present invention are merely exemplary, and it will be understood by those skilled in the art that various modifications and equivalent ranges of embodiments are possible therefrom. Accordingly, the true technical protection scope of the present invention should be defined by the following claims.

Claims (1)

A method of supporting an operational wireless connection of a mobile station to a femtocell base station, the method comprising:
The mobile station is located in both the coverage area of the current base station and the coverage area of another base station, in particular, a femtocell base station, and the mobile station has access grant for the current base station but does not have access grant for the external base station;
A method according to claim 1, wherein a limited connection is allowed between the mobile station and the foreign base station.

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