KR102037144B1 - Method and Apparatus for Distribution of Wireless Link In LTE-WiFi Aggregation system - Google Patents

Abstract

Disclosed are a wireless link distribution method and apparatus in an LWA system. In a method for distributing a radio link in an LWA system according to an embodiment of the present invention, a method for distributing an LTE link or a WiFi link in an LTE-WiFi Aggregation (LWA) system includes: Calculating an LTE resource exhaustion rate which is a ratio of LTE resource usage, calculating a preference based on the LTE resource exhaustion rate, determining a user preferred link using the calculated preferences, the user preferred link, an LTE access cost, Based on at least one of the WiFi connection costs, connecting the user to an LTE link or a WiFi link.

Description

Method and apparatus for wireless link distribution in LWA system {Method and Apparatus for Distribution of Wireless Link In LTE-WiFi Aggregation system}

The present invention relates to a wireless link distribution method and apparatus in an LTE-WiFi Aggregation (LWA) system, and more particularly, to a wireless link in an LWA system that connects an LTE link or a WiFi link in consideration of a user's preferred link and a system access cost. A dispensing method and apparatus are provided.

Recently, wireless data traffic is rapidly increasing in the mobile communication service due to the rapid use of the wireless Internet due to the rapid dissemination of smart phones and the improvement of performance. In order to cope with such an increase in traffic, the processing capacity and performance of the radio access network and the packet core network are being increased. However, many problems have appeared such as a huge investment cost and insufficient response to the increase in traffic.

In order to solve this situation, recently, wireless local area network (WLAN) interworking or WLAN offloading techniques for distributing traffic concentrated in a wireless access network to other networks have been researched and developed. .

The WLAN interworking method utilizes a mobile terminal having both mobile communication and wireless LAN matching functions, and activates a wireless communication interworking function in addition to the mobile communication matching function in a specific time and space conditions, thereby enabling mobile communication matching function and wireless LAN matching function. It means using the wireless internet service by using simultaneously.

Recently, a WLAN interworking method in a wireless access network has been researched and developed in various forms. Representatively, the Licensed Assisted Access (LAA) method, which applies the modified mobile communication method to the wireless LAN frequency band, combines two wireless paths between the mobile communication method in the licensed band and the modified mobile communication method in the unlicensed band. LWA (LTE and Wi-Fi Aggregation), which uses mobile communication and wireless LAN at the same time by combining the existing wireless LAN method without alteration and combining it with the link level inside the wireless access network, This is the case.

LWA is a technology that uses an LTE licensed band as an anchor and aggregates and uses WiFi simultaneously using an unlicensed band. That is, the LWA is a technology in which a terminal accesses an LTE base station (eNB) and requests a service, and the LTE base station examines the network situation and transmits a certain portion of service traffic demand using WiFi. In this way, LWA operates LTE and WiFi simultaneously, and distributes the traffic required by the user to LTE and WiFi.

However, conventionally, the LWA is focused on maximizing system efficiency (maximizing the total transmission speed) by distributing traffic between LTE and WiFi according to network conditions, thus solving the problem of user selection in using two links simultaneously. I can't. In other words, there is a lack of a technique for effectively handling a requirement such as requesting more service traffic allocation to a cheaper WiFi link than an expensive LTE link.

Therefore, when the traffic distribution between LTE and WiFi in the LWA, it is required to develop a technology that can effectively reflect the user preferences while satisfying the user demanded traffic.

In this regard, there is a Korean Patent Application Publication No. 10-2017-0036520 entitled "Method for Selecting an Efficient D2D / Cellular Communication Path in a Heterogeneous Wireless Communication Network".

The technical problem to be solved by the present invention is a wireless link distribution method in the LWA system that can reflect the user's preference (cheap WiFi use or stable quality LTE) while satisfying the user demanded traffic in the traffic distribution between LTE and WiFi in LWA And to provide an apparatus.

The technical problems of the present invention are not limited to the technical problems mentioned above, and other technical problems not mentioned will be clearly understood by those skilled in the art from the following description.

In a method for distributing a radio link in an LWA system according to an embodiment of the present invention for solving the technical problem, in a method for distributing an LTE link or a WiFi link in an LTE-WiFi Aggregation (LWA) system, a connection request is requested. Calculating an LTE resource exhaustion rate, which is a ratio of LTE resource contract amount to LTE resource usage for a user, calculating a preference based on the LTE resource exhaustion rate, and determining a user preferred link using the calculated preferences; Connecting the user to an LTE link or a WiFi link based on at least one of a preferred link, an LTE access cost, and a WiFi access cost.

Preferably, the step of calculating the LTE resource consumption rate, determining whether or not LWA availability through the user's capability (Capability), if the user is an LWA capable user, LTE resource contract amount and the current LTE resource usage Computing the LTE resource consumption rate which is the ratio of.

Preferably, the step of determining the user preferred link, the LTE link preference is higher as the LTE resource consumption rate approaches the minimum value, the higher the WiFi link preference as the maximum value approaches, the value of the exponential function based on the LTE resource consumption rate May be calculated as a preference, generating a random value using a random function, and comparing the random value with the preference to determine a user preferred link.

Preferably, the determining of the user preferred link comprises: determining whether the random value satisfies a condition that is greater than or equal to '0' and less than the preference; and determining the LTE link preference when the random value satisfies the condition. If the condition is not satisfied, the method may include determining the WiFi link preference.

Preferably, the step of connecting the user to the LTE link or WiFi link, comparing the difference between the LTE access cost and the WiFi access cost with a predetermined threshold, if the difference is less than the threshold, to the user preferred link Connecting to a corresponding wireless link, and if the difference is not less than a threshold, connecting to a wireless link that is not a user preferred link.

Advantageously, said LTE connection cost is a value calculated by a function based on LTE link load, with the principle that it increases exponentially with an increase in LTE link load, which is the ratio of LTE link maximum capacity to LTE link traffic, The WiFi connection cost may be a value calculated by a function based on the maximum allowable net WiFi load, which has the principle of increasing exponentially with the difference between the total WiFi maximum load and the maximum allowable net WiFi load.

Preferably, the maximum allowable net WiFi load is a value calculated by the maximum allowable net WiFi traffic relative to the total allowable WiFi traffic, and the maximum allowable net WiFi traffic is the total allowable WiFi traffic and the use of the WiFi link LWA user traffic. It may be a value calculated by the difference of.

In another aspect of the present invention, an apparatus for distributing an LTE link or a WiFi link in an LTE-Wire Aggregation (LWA) system includes an LTE resource for a user who requested access. LTE resource exhaustion rate calculating unit for calculating the LTE resource exhaustion rate which is a ratio of the contract amount to the LTE resource usage, a preference link determination unit for calculating a preference based on the LTE resource exhaustion rate, and determining a user preferred link using the calculated preferences, And a wireless link distribution unit configured to connect the user to the LTE link or the WiFi link based on at least one of the user preferred link, the LTE access cost, and the WiFi access cost.

Preferably, the LTE resource consumption rate calculating unit determines whether or not the LWA is available through the user's capability (Capability), and if the user is an LWA capable user, LTE is the ratio of the LTE resource contract amount and the LTE resource usage to date Resource exhaustion rate can be calculated.

Advantageously, the preferred link determination unit calculates a value of an exponential function based on the LTE resource exhaustion rate to increase the LTE link preference as the LTE resource exhaustion rate approaches the minimum value and increases the WiFi link preference as the access point reaches the maximum value. A random value may be generated using a random function, and the user preference link may be determined by comparing the random value with the preference.

Preferably, the preferred link determining unit may determine that the LTE link is preferred when the random value satisfies a condition equal to or greater than '0' and less than the preference, and may determine the WiFi link preference if the condition is not satisfied.

Preferably, the wireless link distribution unit compares the difference between the LTE access cost and the WiFi access cost with a preset threshold, and when the difference is less than or equal to the threshold, connects to a wireless link corresponding to the user preferred link, If the difference is not below the threshold, it may be connected to a wireless link that is not a user preferred link.

Advantageously, said LTE connection cost is a value calculated by a function based on LTE link load, with the principle that it increases exponentially with an increase in LTE link load, which is the ratio of LTE link maximum capacity to LTE link traffic, The WiFi connection cost may be a value calculated by a function based on the maximum allowable net WiFi load, which has the principle of increasing exponentially with the difference between the total WiFi maximum load and the maximum allowable net WiFi load.

Preferably, the maximum allowable net WiFi load is a value calculated by the maximum allowable net WiFi traffic relative to the total allowable WiFi traffic, and the maximum allowable net WiFi traffic is the total allowable WiFi traffic and the use of the WiFi link LWA user traffic. It may be a value calculated by the difference of.

According to the present invention, LWA system resources can be balanced by reflecting user preferences (cheap WiFi usage or stable quality LTE) while satisfying user demanded traffic in the LWA system.

In addition, according to the present invention, by connecting the LTE link or WiFi link in consideration of the user's preferred link and the system connection cost of the connection request, it is possible to effectively use the frequency resources while maintaining good channel performance.

Effects of the present invention are not limited to the above-mentioned effects, and other effects not mentioned will be clearly understood by those skilled in the art from the following description.

1 is a view for explaining the LWA system according to an embodiment of the present invention.
2 is a diagram illustrating an LWA radio protocol structure for a collocated scenario.
3 is a diagram illustrating an LWA radio protocol structure for a non-collocated scenario.
4 is a flowchart illustrating a method for distributing an LTE link and a WiFi link in an LWA system according to an embodiment of the present invention.
5 is a diagram illustrating a configuration of a radio link distribution apparatus in an LWA system according to an embodiment of the present invention.
6 is a graph illustrating a calculation result of a user preference and a system connection result according to an embodiment of the present invention.

As the invention allows for various changes and numerous embodiments, particular embodiments will be illustrated in the drawings and described in detail in the written description. However, this is not intended to limit the present invention to specific embodiments, it should be understood to include all changes, equivalents, and substitutes included in the spirit and scope of the present invention. In describing the drawings, similar reference numerals are used for similar elements.

Terms such as first, second, A, and B may be used to describe various components, but the components should not be limited by the terms. The terms are used only for the purpose of distinguishing one component from another. For example, without departing from the scope of the present invention, the first component may be referred to as the second component, and similarly, the second component may also be referred to as the first component. The term and / or includes a combination of a plurality of related items or any item of a plurality of related items.

When a component is referred to as being "connected" or "connected" to another component, it may be directly connected to or connected to that other component, but it may be understood that other components may be present in between. Should be. On the other hand, when a component is said to be "directly connected" or "directly connected" to another component, it should be understood that there is no other component in between.

The terminology used herein is for the purpose of describing particular example embodiments only and is not intended to be limiting of the present invention. Singular expressions include plural expressions unless the context clearly indicates otherwise. In this application, the terms "comprise" or "have" are intended to indicate that there is a feature, number, step, operation, component, part, or combination thereof described in the specification, and one or more other features. It is to be understood that the present invention does not exclude the possibility of the presence or the addition of numbers, steps, operations, components, components, or a combination thereof.

Unless defined otherwise, all terms used herein, including technical or scientific terms, have the same meaning as commonly understood by one of ordinary skill in the art. Terms such as those defined in the commonly used dictionaries should be construed as having meanings consistent with the meanings in the context of the related art and shall not be construed in ideal or excessively formal meanings unless expressly defined in this application. Do not.

In the present specification, the LTE link may mean the same as the LTE resource, the LTE traffic, the LTE bandwidth, and the like, and the Wi-Fi link may mean the same as the Wi-Fi resource, the Wi-Fi traffic, the Wi-Fi bandwidth, and the like.

In addition, in the present specification, WiFi and WLAN may have the same meaning.

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

1 is a diagram illustrating an LWA system according to an embodiment of the present invention, FIG. 2 is a diagram illustrating an LWA radio protocol structure for a collocated scenario, and FIG. 3 is a diagram for an LWA radio protocol structure for a non-collocated scenario. Drawing.

 Referring to FIG. 1, an LWA system according to an embodiment of the present invention may include at least one user equipment (UE) 100, a base station 200, a WLAN termination (WT) 300, and a core network 400. Include.

The terminal 100 is a communication device moved by a user. The terminal 100 may be fixed or mobile, and may be called by other terms such as a mobile station (MS), a user terminal (UT), a subscriber station (SS), and a wireless device.

The base station 200 generally refers to a station that communicates with the terminal 100, and includes a Node-B, an evolved Node-B, an Sector, a Site, and a BTS. The base transceiver station 200 may be referred to in other terms such as a base transceiver system, an access point, a relay node, a remote radio head, a radio unit, or a small cell. It should be interpreted in a comprehensive sense to indicate some areas or functions covered by the base station controller (BSC) of the BSC, the NodeB of the WCDMA, the eNB or the sector (site) in the LTE, and the like: megacell, macrocell, microcell, picocell. It is meant to cover all the various coverage areas such as femtocell and relay node, RRH, RU, and small cell communication range. Therefore, megacells, macrocells, microcells, picocells, femtocells, small cells, RRHs, antennas, RUs, low power nodes (LPNs), points, eNBs, transmit / receive points, transmit points, and receive points are collectively referred to as base stations. do.

Preferably, the base station 200 may be an evolved node-B (eNB), and a plurality of terminals 100 may exist in an area covered by each base station.

The base station 200 supports LTE-WLAN aggregation (LWA) operation and configures the terminal 100 to request access to use an LTE link and a WiFi link.

Meanwhile, two scenarios may be supported depending on the backhaul connection between the LTE and the WLAN in the LWA. One is a co-located LWA scenario for non-ideal backhaul, and the other is a co-located LWA scenario for ideal / internal backhaul.

In an LWA scenario that is not co-located, the base station 200 may be connected to one or more WLAN terminations (WTs) 300 via an Xw interface. WT 300 terminates the Xw interface to the WLAN. That is, the WT 300 may be a logical node terminating the Xw interface at the WLAN side, and 3GPP may not specify where to implement it.

In a co-located LWA scenario, the interface between LTE and WLAN may depend on the implementation. For LWA, the only interfaces required for core network 400 are S1-U and S1-MME, which are terminated at base station 300. The core network interface may not be required for the WLAN. The core network 400 includes a mobility management entity (MME) and a serving gateway (S-GW). The MME / S-GW may be located at the end of the network. A packet data network (PDN) gateway (P-GW) may be connected to an external network.

In addition, the radio protocol architecture (architecture) used by a particular bearer in the LWA may depend on the LWA backhaul scenario and how the bearer is established. There are two bearer types for LWA, such as FIGS. 2 and 3. One is a split LWA bearer and the other is a switched LWA bearer. A split LWA bearer refers to a bearer in which a radio protocol exists in both the base station and the WLAN to use both LTE and WLAN resources. Switched LWA Bearer A Switched LWA Bearer represents a bearer in which a wireless protocol exists at both the base station and the WLAN but uses only WLAN resources.

2 shows the LWA radio protocol architecture for the Collocated scenario, and FIG. 3 shows the LWA radio protocol architecture for the Non-Collocated scenario.

LTE-WLAN Aggregation Adaptation Protocol (LWAAP) generates LWA PDUs containing DRB identifiers for PDUs delivered over WLAN in LWA operations, and WT 300 uses LWA EtherType to forward data to UEs via WLAN. use. The terminal 100 uses the LWA EtherType to determine whether the received PDU belongs to the LWA bearer. The DRB identifier is then used to determine which LWA bearer the PDU belongs to.

In the downlink, LWA supports a split bearer operation in which the PDCP sublayer of the terminal 100 supports in-sequence delivery of upper layer PDUs based on a reordering procedure introduced in dual connectivity. In the uplink, PDCP PDUs are sent only over LTE.

In this way, the Rel-13 LWA bearer configures an LTE Layer2 entity for uplink transmission to the terminal 100 in order for both the split LWA bearer and the switched LWA bearer to transmit PDCP PDUs on the uplink through LTE. Therefore, the terminal 100 uses the reordering function applied to the dual connectivity split bearer specified in the PDCP standard as well as when the split LWA bearer is configured. Through this, even when reconfiguration of the switched LWA (reconfiguration from the LTE bearer to the switched LWA bearer or reconfiguration from the switched LWA bearer to the LTE bearer) occurs, the UE reorders and receives the PDUs out of order through two paths. Could.

As illustrated, the base station 200 supports LTE-WLAN aggregation (LWA) operation and performs aggregation between two radio links through an LWA Application Protocol (LWAAP) connected to a Packet Data Convergence Protocol (PDCP).

In addition, the base station 200 is configured to enable the user requesting access to use the LTE link and WiFi link. That is, the base station 200 needs to check whether the user who requested access is an LWA user. To this end, the base station 200 requests a UE radio access capability transmission to the terminal 100 (UECapabilityEnquiry), the terminal 100 reports the capability (UECapabilityInformation) including whether the LWA support, supported WLAN band information, etc. do. Then, the base station 200 may check whether the user supports the LWA through the capability transmitted from the terminal 100.

Thereafter, the base station 200 calculates the exhaustion rate of the LTE resource contract amount of the LWA user, and determines the user preferred link based on the LTE resource exhaustion rate. Here, the exhaustion rate of the LTE resource contract amount may be the ratio of the LTE resource usage to the present to the LTE resource contract amount, the LTE resource contract amount means the LTE resource of the limited capacity allocated by the LWA user according to the contract with the operator, LTE resource Usage may refer to usage of LTE resources that have been used up to date.

Specifically, the user has limited traffic capable capacity (ie, LTE resource contract amount) according to the contract with the operator in accessing the system. Depending on the plan, the amount of data that can be transferred (eg, 42,000 won for 2GB) is determined, and if you generate more than the contracted traffic, you are required to purchase additional access capacity. Using LTE alone has no room for user preference, but in LWA, which simultaneously utilizes a WiFi link that generates lower system access costs than LTE link, bandwidth preference occurs depending on the amount of contract traffic. In other words, if a sufficient amount of contract traffic is left, a stable LTE link is preferred, and if the amount of remaining contract traffic is low due to a large amount of contracted traffic, a cheaper WiFi link is preferred.

If the user preferred link is determined, the base station 200 accesses the LTE link or the WiFi link in consideration of the user preferred link and the system connection cost. That is, the base station 200 compares the difference between the LTE access cost and the WiFi access cost with a preset threshold, and if the difference is less than or equal to the threshold, connects to the wireless link corresponding to the user preferred link, and the difference is not less than or equal to the threshold. If it is connected to a wireless link rather than a user preferred link. Here, the system access cost includes an LTE access cost and a WiFi access cost. The LTE access cost is a system access cost when using LTE. Since the value varies according to the traffic of the LTE link, it can be calculated in real time. The WiFi system access cost is the system access cost when using WiFi. Since the value varies depending on the maximum allowable load (ie, the maximum allowable net WiFi load) of a user who uses pure WiFi only, the WiFi access fee can be calculated in real time. have.

As described above, the base station 200 may connect an LTE link or a WiFi link in consideration of a user's preferred link and a system connection cost in real time.

A detailed description of how the base station 200 distributes a radio link (LTE link, WiFi link) to each user in real time will be described with reference to FIG. 4.

4 is a flowchart illustrating a method for a base station to distribute an LTE link and a WiFi link in an LWA system according to an embodiment of the present invention.

Referring to FIG. 4, when an access of a user is attempted (S410), the base station calculates an LTE resource consumption rate that is the amount of LTE resource usage compared to the LTE resource contract amount to the requested user (S420). At this time, the base station needs to confirm whether the user (terminal) requested to access the LWA. Accordingly, the base station may request UE radio access capability transmission (UECapabilityEnquiry) to determine whether the corresponding terminal supports LWA or WLAN band information supported by the terminal. Then, the terminal reports the capability (UECapabilityInformation) including whether the LWA support, supported WLAN band information. The base station may check whether the user supports the LWA through the capability transmitted from the terminal.

When the user is identified as the LWA support user, the base station requests and receives the LTE resource contract amount of the user who requested the access and the LTE resource usage so far to the core network. For example, it is possible to receive the LTE resource contract amount and the LTE resource usage to date from the billing server. Here, the LTE resource contract amount may mean an LTE resource of a limited capacity allocated by an LWA system user according to a contract with an operator, and the LTE resource usage amount may mean an LTE resource that has been exhausted up to now. In addition, the base station may request and receive the LTE resource contract amount of the user who requested access and the LTE resource usage to date. In addition, the base station may request and receive the LTE resource contract amount of the user and the LTE resource usage to date through the capability.

When the base station receives the LTE resource contract amount of the LWA resource user and the LTE resource usage up to now, the base station calculates the LTE resource consumption rate, which is the LTE resource usage amount compared to the LTE resource contract amount of the user. In this case, the calculated LTE resource consumption rate r may be, for example, a value between 0 and 1 (0 <= r <= 1). For example, as the number of LTE resources is used, the LTE resource consumption rate may have a value close to '0', and as the number of LTE resources is used, the LTE resource consumption rate may have a value close to '1'.

When step S420 is performed, the base station calculates a preference based on the LTE resource consumption rate (S430). In other words, the base station is an LTE link preference is extremely high as the LTE resource consumption rate approaches the minimum value (eg, '0'), and the LTE link preference becomes extremely high as the maximum value (eg, '1') is approached. The value of the exponential function based on the resource exhaustion rate is calculated as a preference. At this time, the preference function (y) for calculating the preference is an exponential function such as "y = ae ^ r + b". It may be in the form. In other words, when LTE resource exhaustion rate r is '0' (r = 0), the preference is '1' (y = 1) (LTE link preference) and LTE resource exhaustion rate is '1' (r = 1). In this case, since the preference should satisfy '0' (y = 0) (WiFi link preference), the preference function for determining the preference may be as shown in Equation 1 below. Therefore, the preference y (r) may be a value calculated through Equation 1.

The closer the preference calculated through Equation 1 to '1', the better the LTE link preference, and the closer the preference to the '0', the WiFi link preference. As described above, although the user's favorite link can be determined through the preference, the user's link needs to be distributed stochastically. The random function can be used for this.

Accordingly, the base station generates a random value using a random function (S440), and compares the generated random value with a preference to determine a user preferred link (S450). That is, whenever the traffic demand of the LWA user occurs, the base station generates a random value of the random function w = random (0, 1) as an arbitrary value between 0 and 1. Thereafter, the base station determines whether the random value satisfies a condition (0 <= w <= y (r)) that is greater than or equal to '0' and less than the preference. If the above conditions are not satisfied, it is determined that the WiFi link is preferred.

For example, User 1 having a preference of 0.8 and a random value of 0.5 may determine that the LTE link is preferred, and User 2 having a preference of 0.7 and a random value of 0.9 may determine that the WiFi link is preferred.

On the other hand, the base station can connect the user to the user preferred link determined through the above process, but the system connection cost generated due to the use of LTE and WiFi is different, so the system connection cost should also be considered. That is, since LTE generates relatively high cost and WiFi generates low cost, it is necessary to consider the user access link as well as the system connection cost.

Accordingly, the base station compares the difference between the LTE access cost and the WiFi access cost with a preset threshold (S460), and if the threshold value is less than the threshold, approves the access to the user preferred link (S470). Induce a connection other than the radio link (S480). In this case, the base station may use the value if the LTE access cost and the WiFi access cost is calculated in real time and stored in advance, and if not stored, the base station may calculate and use the LTE access cost and the WiFi access cost, respectively.

)은 LTE를 이용할 때의 시스템 접속 비용으로, LTE 링크 최대 수용량 대 LTE 링크 트래픽의 비율인 LTE 링크 부하의 증가에 따라 기하급수적으로 증가하는 원리를 갖는, LTE 링크 부하에 기초한 함수에 의해 산출된 값일 수 있다. 즉, LTE 접속 비용(

)은 LTE 링크의 트래픽(

)이 증가하여 LTE 링크의 최대 수용량(

)에 가까워질수록 시스템 접속비용이 급격히 비싸진다는 원리에 의해 산출된 값일 수 있다. 이때, 함수는 2차 함수, 3차 함수 등 2차 이상의 함수일 수 있다. LTE connection costs (

) Is a system connection cost when using LTE, and is a value calculated by a function based on the LTE link load, which has the principle of increasing exponentially with the increase of the LTE link load, which is the ratio of the maximum LTE link capacity to the LTE link traffic. Can be. That is, LTE connection cost (

) Is the traffic on the LTE link (

) Increases the maximum capacity of the LTE link (

It may be a value calculated based on the principle that the closer to the cost, the higher the system connection cost is. In this case, the function may be a quadratic function such as a quadratic function and a tertiary function.

)은 WiFi를 이용할 때의 시스템 접속비용으로, WiFi 전체 최대 부하와 최대 허용가능 순 WiFi 부하의 차의 증가에 따라 기하급수적으로 증가하는 원리를 갖는, 최대 허용가능 순 WiFi 부하에 기초한 함수에 의해 산출된 값일 수 있다. 즉, WiFi 접속 비용(

)은 WiFi 링크를 사용하는 LWA 사용자 트래픽(

)의 증가에 따라서 LWA를 제외한 순수한 WiFi 사용자들의 최대 허용 부하율(즉, 순수 WiFi 사용자들이 가용할 수 있는 여유 용량)이 전체 WiFi 용량의 절반(50%)에 가깝게 감소할수록 시스템 접속비용이 급격히 비싸진다는 원리에 의해 산출된 값일 수 있다. 이때, 함수는 2차함수, 3차 함수 등 2차 이상의 함수일 수 있다. WiFi connection costs (

) Is a system connection cost when using WiFi, and is calculated by a function based on the maximum allowable net WiFi load, which has the principle of increasing exponentially with the difference between the maximum total WiFi load and the maximum allowable net WiFi load. It may be a value. In other words, WiFi connection costs (

) Shows LWA user traffic using the WiFi link (

), As the maximum allowable load rate of pure WiFi users excluding LWA (i.e. free capacity available to pure WiFi users) decreases to close to half (50%) of the total WiFi capacity, the system connection cost will increase rapidly. It may be a value calculated by the principle. In this case, the function may be a quadratic function such as a quadratic function, a cubic function, and the like.

)과 WiFi 접속 비용(

)에 대해 구체적으로 설명하기로 한다. LTE connection costs (

) And WiFi connection costs (

) Will be described in detail.

,

)의 증가에 따라 기하급수적으로 증가하는 한계가격

을 적분한 누적비용(Accumulated cost)에 미세한 우선순위 조정을 위한 정책인자(policy factor)

을 더한 값인 아래 기재된 수학식 2를 이용하여 구할 수 있다. The LTE access cost is determined by the marginal price. LTE connection costs depend on the load on the LTE link (

,

Marginal price increases exponentially with increasing

Policy factor for fine-tuning priorities to cumulative cumulative costs

It can be obtained using Equation 2 described below, which is the sum of.

)을 LTE 링크의 트래픽(

)에 대한 가격으로 바꾸기 위해서 수학식 2를 풀면

은

이고,

이다. 따라서, LTE 링크의 트래픽에 대한 LTE 접속 비용은 아래 기재된 수학식 3을 이용하여 산출할 수 있다. Where the LTE access cost for the load on the LTE link (

) To the traffic on the LTE link (

Solving Equation 2 to change to the price for)

silver

ego,

to be. Therefore, the LTE access cost for the traffic of the LTE link can be calculated using Equation 3 described below.

Here, a ₃ , b ₁ may be any value.

)(Maximum Reachable Load for Pure WiFi User)를 지표로 삼는다.

가 WiFi 전체의 최대 부하(즉, 100%)에서

를 뺀 값(

)이라고 할 때,

는 LWA 사용자가 WiFi를 이용하여 서비스 트래픽을 전송할 때 발행하는 부하를 의미하게 된다. 이에,

에 대한 시스템 접속 비용은

가 증가함에 따라 기하급수적으로 비용이 증가하는 한계가격

을 적분해서 구한 누적비용에 정책인자(

)를 더한 값인 아래 기재된 수학식 4를 이용하여 구할 수 있다. Constraints for indicating WiFi connection costs include the "maximum allowable net WiFi load" that varies as LWA users transmit traffic over the WiFi link.

(Maximum Reachable Load for Pure WiFi User).

At full load (i.e. 100%) over WiFi

Minus (

))

Denotes the load issued by the LWA user when transmitting service traffic using WiFi. Therefore,

System connection costs for

Marginal price increases exponentially with increasing cost

To the cumulative cost obtained by integrating

Can be obtained using Equation 4 described below, which is the sum of

는

이고,

이므로,

는

가 된다. 순수하게 WiFi만 사용하는 사용자의 최대 허용가능 부하(

)는 WiFi 링크 트래픽(

)으로부터 구할 수 있다. 순수하게 WiFi만 사용하는 사용자의 최대 허용가능 부하(

)는 WiFi의 총 가능 트래픽(

) 대비 최대 허용가능 순 WiFi 트래픽이고, 최대 허용가능 순 WiFi 트래픽은 LWA사용자가 WiFi 링크를 사용하여 전송하는 트래픽 양(

)로부터 구할 수 있다(즉,

). 이에, 순수하게 WiFi만 사용하는 사용자의 최대 허용가능 부하(

)는

로 구해진다. 이렇게 구한

를

의 식에 대입하면 LWA 사용자가 WiFi 링크를 이용하여 트래픽을 전송할 때 발생하는 시스템 비용은 아래 기재된 수학식 5와 같다. Solving Equation 4

Is

ego,

Because of,

Is

Becomes Maximum allowable load for users using purely WiFi (

) Is the WiFi link traffic (

Can be obtained from Maximum allowable load for users using purely WiFi (

) Is the total available traffic for WiFi (

) Is the maximum allowable net WiFi traffic, and the maximum allowable net WiFi traffic is the amount of traffic the LWA user sends using the WiFi link (

), I.e.

). Therefore, the maximum allowable load of the user using purely WiFi (

)

Obtained by So obtained

To

Substituting the equation, the system cost incurred when the LWA user transmits the traffic using the WiFi link is expressed by Equation 5 below.

That is, the WiFi connection cost may be calculated using Equation 5.

Here, a ₂ , b ₂ may be any value.

When the LTE access cost and the WiFi access cost are calculated using the above-described equations, the base station compares the difference between the two access costs with a threshold, and connects to the wireless link corresponding to the user preferred link when the difference is less than the threshold. If the difference is not less than the threshold value is connected to the radio link rather than the user preferred link.

For example, when the user preferred link is an LTE link, if the difference between the LTE access cost and the WiFi access cost is less than or equal to the threshold, the connection may be granted to the LTE link, and if not, the access link may be induced to the WiFi link. In addition, when the user preference link is a WiFi link, if the difference between the LTE access cost and the WiFi access cost is less than the threshold, the connection may be granted to the WiFi link, and if not below the threshold, the connection may be induced to the LTE link.

On the other hand, in the embodiment of the present invention has been described as to distribute the radio link by the terminal unit using the user in the same meaning as the terminal, each user can execute a plurality of applications, it is also possible to distribute the radio link by application unit .

5 is a diagram illustrating a configuration of a radio link distribution apparatus in an LWA system according to an embodiment of the present invention.

Referring to FIG. 5, in the LWA system according to an embodiment of the present invention, the wireless link distribution apparatus 500 includes a communication unit 510, an LTE resource consumption rate calculating unit 520, a preferred link determination unit 530, and a wireless link distribution. Allocation 540 is included.

The communication unit 510 is configured to communicate with a terminal and is used to transmit and receive signals, messages, and data necessary for carrying out the present invention.

The LTE resource exhaustion rate calculator 520 calculates an LTE resource exhaustion rate, which is a ratio of LTE resource contract amount to LTE resource usage, for a user who is requested to access. In this case, the LTE resource consumption rate calculating unit 520 determines whether LWA is available through the capability of the user who requested access, and if the user is an LWA-capable user, the LTE resource consumption is the ratio of LTE resource usage until now. Calculate the resource consumption rate.

The preferred link determination unit 530 calculates a preference based on the LTE resource consumption rate, and determines the user preferred link using the calculated preference. That is, the preferred link determination unit 530 calculates the value of the exponential function based on the LTE resource exhaustion rate, which increases the LTE link preference as the LTE resource exhaustion rate approaches the minimum value and increases the WiFi link preference as the approaching maximum value approaches the maximum value. . Thereafter, the preferred link determination unit 530 generates a random value using a random function, and compares the random value with a preference to determine a user preferred link. That is, the preferred link determination unit 530 may determine that the LTE link is preferred when the random value satisfies a condition that is greater than or equal to '0' and less than the preference, and determines that the WiFi link is preferred when the condition is not satisfied.

The wireless link distribution unit 540 connects the user to the LTE link or the WiFi link based on at least one of the user preferred link, the LTE access cost, and the WiFi access cost. That is, the wireless link distribution unit 540 compares the difference between the LTE access cost and the WiFi access cost with a preset threshold, and if the difference is less than or equal to the threshold, connects to the wireless link corresponding to the user preferred link, and the difference is less than or equal to the threshold. If not, connect to a wireless link that is not a user preferred link.

Meanwhile, the wireless link distribution apparatus 500 according to the present invention may further include a storage unit (not shown) in which a program or application for wireless link distribution, such as determining a user preference link and calculating a system connection cost, is stored. In addition, the wireless link distribution apparatus 500 may further include a controller (not shown) for controlling the operation of various components of the wireless link distribution apparatus 500.

The radio link distribution apparatus 500 having the above-described configuration may be a base station itself or a device inside the base station.

6 is a graph illustrating a calculation result of a user preference and a system connection result according to an embodiment of the present invention. This is a graph that calculates the connection result of the LTE link and the WiFi link based on a month when there are a large number of users and the plurality of users have their own traffic capacity.

(a) is a user preference graph, in which a plurality of users express LTE link or WiFi link preference by a user preference function regardless of the actual system connection result. On day 1, we can see that many users prefer LTE links because most users have not consumed the available traffic (the y-axis of the graph is the total amount of traffic attempted by the user, calculated in Mbps). Over time, each user will consume the available traffic and will tend to prefer the WiFi link. As we approach day 30, most users will run out of available traffic, indicating that many users prefer a WiFi link.

(b) is a system connection graph, which shows the result of the user's system grasping the user's preference and determining the system (ie, LTE link or WiFi link) to actually connect. On the basis of one month, it is found that the user accepts most user preferences in the early stages, so that the frequency of LTE link usage is high, but it does not unconditionally accept the WiFi link preferences that occur over time, and induces system access to balance the LTE and WiFi links. Can be.

So far I looked at the center of the preferred embodiment for the present invention. Those skilled in the art will appreciate that the present invention can be implemented in a modified form without departing from the essential features of the present invention. Therefore, the disclosed embodiments should be considered in descriptive sense only and not for purposes of limitation. The scope of the present invention is shown in the claims rather than the foregoing description, and all differences within the scope will be construed as being included in the present invention.

100: terminal
200: base station
300: WT
400: core network
500: wireless link distribution device
510: communication unit
520: LTE resource consumption rate calculation unit
530: preferred link determination unit
540: wireless link distribution unit

Claims (14)

In the LTE-WiFi Aggregation (LWA) system, the base station distributes the LTE link or WiFi link,
Calculating an LTE resource consumption rate, which is a ratio of LTE resource contract amount to LTE resource usage, for a user who is requested to access;
Calculating a preference based on the LTE resource consumption rate, and determining a user preferred link using the calculated preference;
Connecting the user to an LTE link or a WiFi link based on at least one of the user preferred link, LTE access cost, and WiFi access cost,
The LTE connection cost is a value calculated by a function based on the LTE link load, which has a principle that increases exponentially with the increase of the LTE link load, which is the ratio of the maximum LTE link capacity to the LTE link traffic. Wireless link distribution method. The method of claim 1,
Computing the LTE resource consumption rate,
Determining whether LWA is available based on the user's capability;
If the user is an LWA capable user, calculating an LTE resource consumption rate which is a ratio of the LTE resource contract amount and the LTE resource usage to date. The method of claim 1,
Determining the user preference link,
Calculating a value of an exponential function based on the LTE resource exhaustion rate as the LTE resource exhaustion rate becomes higher as the LTE resource exhaustion rate approaches the minimum value, and the WiFi link preference becomes higher as the LTE resource exhaustion rate approaches the maximum value;
Generating a random value using a random function; And
And comparing the random value with the preference to determine a user preferred link. The method of claim 3,
Determining the user preference link,
Determining whether the random value satisfies a condition equal to or greater than '0' and less than a preference;
And determining the LTE link preference when the random value satisfies the condition, and determining the WiFi link preference when the random value does not satisfy the condition. The method of claim 1,
Connecting the user to the LTE link or WiFi link,
Comparing the difference between the LTE access cost and the WiFi access cost with a preset threshold; And
If the difference is less than or equal to a threshold, connecting to a wireless link corresponding to the user preferred link; and if the difference is not less than or equal to a threshold, connecting to a radio link that is not a user preferred link. Link distribution method. The method of claim 5,
The WiFi connection cost is a value calculated by a function based on the maximum allowable net WiFi load, which has the principle of increasing exponentially with the difference between the maximum WiFi full load and the maximum allowable net WiFi load. How to distribute radio links in LWA systems. The method of claim 6,
The maximum allowable net WiFi load is a value calculated by the maximum allowable net WiFi traffic relative to the total allowable WiFi traffic, and the maximum allowable net WiFi traffic is determined by the difference between the total allowable WiFi traffic and the use of the WiFi link-enabled LWA user traffic. Wireless link distribution method in the LWA system, characterized in that the calculated value. An apparatus for distributing an LTE link or a WiFi link in an LTE-Wag Aggregation (LWA) system,
An LTE resource exhaustion rate calculator configured to calculate an LTE resource exhaustion rate, which is a ratio of LTE resource contract amount to LTE resource usage for a user who is requested to access;
A preference link determination unit which calculates a preference based on the LTE resource consumption rate and determines a user preferred link using the calculated preference;
On the basis of at least one of the user preferred link, LTE connection costs, WiFi connection costs, including a wireless link distribution unit for connecting the user to the LTE link or WiFi link,
The LTE connection cost is a value calculated by a function based on the LTE link load, which has a principle that increases exponentially with an increase in the LTE link load, which is the ratio of maximum LTE link capacity to LTE link traffic. Dispensing device. The method of claim 8,
The LTE resource consumption rate calculation unit,
It is determined whether the LWA is available through the user's capability (Capability), and if the user is an LWA capable user, the radio link, characterized in that the LTE resource consumption rate which is the ratio of the LTE resource contract amount and the LTE resource usage to date Dispensing device. The method of claim 8,
The preferred link determination unit,
As the LTE resource consumption rate approaches the minimum value, the LTE link preference becomes higher, and as the maximum value approaches the WiFi link preference, the value of the exponential function based on the LTE resource consumption rate is calculated as a preference, and the random value is used as a random function. And determine the user preferred link by comparing the random value with the preference. The method of claim 10,
The preferred link determination unit,
And if the random value satisfies a condition equal to or greater than '0' and less than the preference, determines the LTE link preference, and if the condition is not satisfied, determines the WiFi link preference. The method of claim 8,
The wireless link distribution unit,
The difference between the LTE access cost and the WiFi access cost is compared with a preset threshold, and when the difference is less than or equal to the threshold, the wireless link corresponding to the user preferred link is connected. If the difference is not less than or equal to the threshold, the user is preferred. And a wireless link distribution device. The method of claim 12,
The WiFi connection cost is a value calculated by a function based on the maximum allowable net WiFi load, which has the principle of increasing exponentially with the difference between the maximum WiFi full load and the maximum allowable net WiFi load. Wireless link distribution device. The method of claim 13,
The maximum allowable net WiFi load is a value calculated by the maximum allowable net WiFi traffic relative to the total allowable WiFi traffic, and the maximum allowable net WiFi traffic is determined by the difference between the total allowable WiFi traffic and the use of the WiFi link-enabled LWA user traffic. And a calculated value.

Images