KR101961740B1 - Hand over control apparatus and control method thereof - Google Patents

Abstract

SUMMARY OF THE INVENTION The present invention provides an environment in which channel quality mismatch phenomenon and traffic volume asymmetry between a downlink and an uplink can occur between a terminal and a base station due to various types of base stations being concentrated in the same area and providing various types of communication services to the terminal Discloses a handover related apparatus and a handover related apparatus operation method capable of determining an optimal target base station at the time of handover and consequently improving the performance of a mobile communication service.

Description

[0001] DESCRIPTION [0002] HAND OVER CONTROL APPARATUS AND CONTROL METHOD THEREOF [0003]

The present invention relates to a handover related apparatus and a method of operating a handover related apparatus, and more particularly, to a handover related apparatus and a handover related apparatus, Considering an environment in which a channel quality mismatch phenomenon and traffic amount asymmetry may occur between a link and an uplink, an optimal target base station can be determined at the time of handover, and consequently, a handover related And a method of operating a device related to the handover.

In recent LTE networks, heterogeneous network technology has been emerged in which base station devices with different cell sizes are located in the same area to increase the frequency utilization rate. Besides a typical macro base station, various types of small cells with smaller coverage are arranged. According to coverage of small cells, various types of base station devices such as Femto, Pico, Micro, and Metro cell form coverage in the overlapped area and provide wireless service to users.

In this heterogeneous network environment, since there are many areas where service coverage overlaps, signal interference between BSs may increase and handover between BSs may occur frequently.

Typically, a handover scheme measures information related to downlink channel quality of a serving base station and a neighboring base station to which a user terminal or user equipment (hereinafter referred to as "UE") is currently connected and receives a service, And the serving base station compares the downlink channel quality based on the information reported from the UE to determine the base station to be handed over, that is, the target base station. That is, the current handover scheme determines the target base station to be handed over only considering the downlink channel quality of the serving base station and the neighbor base station.

Meanwhile, the UE uses uplink and downlink for data transmission / reception through a wireless connection with the base station.

The mismatch of the channel quality between the downlink and the uplink may occur due to the difference of the base station transmission power depending on the type of the base station. Especially, in case of heterogeneous network, channel quality mismatch phenomenon between downlink and uplink may occur more greatly.

In addition, in a communication system based on packet switching such as LTE and WiMAX, irregular traffic generation and asymmetry between uplink traffic and downlink traffic may occur.

Therefore, in an environment where channel quality discrepancy and traffic amount asymmetry may occur between downlink and uplink as described above, handover is performed considering only downlink channel quality as in the current handover scheme There will be a limit in determining the optimal target base station.

Accordingly, the present invention proposes a method for determining an optimal target BS for handover considering an environment in which channel quality mismatch between downlink and uplink and traffic asymmetry may occur.

SUMMARY OF THE INVENTION The present invention has been made in view of the above circumstances, and it is an object of the present invention to provide a mobile communication system in which various kinds of base stations are concentrated in the same area and various kinds of communication services are provided to the terminal, Considering the environment where inter-link channel quality mismatch phenomenon and traffic amount asymmetry may occur, it is possible to determine an optimal target base station at the time of handover, and as a result, a handover related device and a handover related And to propose an operation method of the apparatus.

According to a first aspect of the present invention, there is provided a handover related apparatus comprising: a data rate measuring unit for measuring at least one of a downlink related data rate and an uplink related data rate from a connected base station connected to a terminal; An attenuation ratio confirmation unit for confirming an attenuation rate required for estimating a data rate of an adjacent base station based on a data rate of the access point for each of at least one neighbor base station associated with the terminal; A valid data rate confirmation unit for confirming a valid data rate for the connection base station based on at least one of the downlink related data rate and the uplink related data rate; An estimated data rate identifying unit for determining an estimated data rate for the at least one neighbor base station based on the effective data rate and the decay rate of each of the at least one neighbor base station; And determining a base station of one of the connection base station and the at least one neighbor base station as a handover target base station of the terminal based on the effective data rate for the connection base station and the estimated data rate for the at least one neighbor base station And a target base station determining unit.

Advantageously, the data rate measurer is configured to determine, based on the maximum downlink data rate measured at the connection base station and the average downlink data rate for at least one terminal connected to the connection base station during a particular data rate measurement interval, The data rate related to the downlink can be measured.

Advantageously, the data rate measurement unit is configured to determine, based on the maximum uplink data rate measured at the connection base station and the average uplink data rate for at least one terminal connected to the connection base station during a particular data rate measurement interval, The uplink-related data rate can be measured.

Preferably, the effective data rate checker may determine, based on the downlink-related data rate to which the predetermined first weight is applied and the uplink-related data rate to which the predetermined second weight is applied, The effective data rate can be calculated.

Preferably, the determined attenuation rate for each of the at least one neighbor base station may include a downlink-related signal attenuation rate and an uplink-related signal attenuation rate predicted for each of the at least one neighbor base station based on the connection base station have.

Preferably, the estimated data rate checker determines the estimated data rate for each of the at least one neighboring base station based on the downlink-related data rate to which at least one of the downlink-related signal attenuation rate and the predetermined first weight is applied, A signal attenuation rate, and a predetermined second weight, to calculate the estimated data rate based on the uplink-related data rate.

Preferably, the first weight and the second weight are determined based on the type of the communication service provided to the terminal, and when the downlink data amount is a communication service larger than the uplink data amount, If the amount of uplink data is larger than the amount of downlink data, the second weight may be set to be larger than the first weight.

Preferably, Wherein the downlink-related signal attenuation rate of a specific neighbor base station among the at least one neighbor base station is determined based on a received signal quality value of the connected base station, which is confirmed in downlink-related channel quality information received from the terminal, Lt; / RTI >

Preferably, the uplink-related signal attenuation rate of a specific neighboring base station among the at least one neighboring base station is determined based on the received signal strength value of the connected base station identified in the downlink-related channel quality information received from the terminal, May be calculated using the received signal strength value.

Preferably, the target BS determining unit compares a maximum estimated data rate among the estimated data rates for the at least one neighbor BS with a valid data rate for the connected BS, and if the effective data rate for the connected BS is The handover of the UE can be prevented from being performed.

Preferably, Wherein the target base station determining unit determines a data rate having a maximum value among an effective data rate of the access point and an estimated data rate of the at least one neighboring base station and determines a base station having a data rate of the identified maximum value as the target base station .

According to a second aspect of the present invention, there is provided a method for operating a handover related apparatus, the method comprising the steps of: measuring a data rate measured from at least one of a downlink-related data rate and an uplink- step; An attenuation rate confirmation step of confirming an attenuation rate required for estimating a data rate of an adjacent base station based on a data rate of the access point for each of at least one neighbor base station associated with the terminal; Determining a valid data rate for the connection base station based on at least one of the downlink-related data rate and the uplink-related data rate; Determining an estimated data rate for the at least one neighbor base station based on the effective data rate and the decay rate of each of the at least one neighbor base station; And determining a base station of one of the connection base station and the at least one neighbor base station as a handover target base station of the terminal based on the effective data rate for the connection base station and the estimated data rate for the at least one neighbor base station And a target base station determination step.

Preferably, the valid data rate check step may include a step of checking the valid data rate based on the downlink related data rate to which the predetermined first weight is applied and the uplink related data rate to which the predetermined second weight is applied, The effective data rate can be calculated.

Preferably, the determined attenuation rate for each of the at least one neighbor base station may include a downlink-related signal attenuation rate and an uplink-related signal attenuation rate predicted for each of the at least one neighbor base station based on the connection base station have.

Preferably, the step of verifying the estimated data rate may further include determining, for each of the at least one neighboring base station, the downlink-related data rate to which at least one of the downlink-related signal attenuation rate and a predetermined first weight is applied, And the uplink-related data rate to which at least one of the related signal attenuation rate and the predetermined second weight is applied.

Preferably, the first weight and the second weight are determined based on the type of the communication service provided to the terminal, and when the downlink data amount is a communication service larger than the uplink data amount, If the amount of uplink data is larger than the amount of downlink data, the second weight may be set to be larger than the first weight.

Preferably, the downlink-related signal attenuation rate of a specific neighboring base station among the at least one neighboring base station is determined based on a downlink-related channel quality information received from the terminal, Lt; / RTI >

Preferably, the uplink-related signal attenuation rate of a specific neighboring base station among the at least one neighboring base station is determined based on the received signal strength value of the connected base station identified in the downlink-related channel quality information received from the terminal, May be calculated using the received signal strength value.

Advantageously, if the maximum data rate of the estimated data rate for the at least one neighboring base station is compared to the effective data rate for the connected base station, and the comparison indicates that the effective data rate for the connected base station is greater, And not performing the handover.

Preferably, the target base station determining step determines a data rate having a maximum value among the effective data rate of the connected base station and the estimated data rate of the at least one neighbor base station, It can be determined to be the target base station.

Therefore, according to the handover related device and the method of operating the handover related device of the present invention, unlike the conventional method of determining the target BS by considering only the downlink related channel quality information received from the MS, Determining a target base station based on a data rate of a connected base station and neighbor base stations that are confirmed in consideration of the downlink related data rate, the uplink related data rate, and the downlink related channel quality information received from the terminal, As the base station is concentrated and provides various types of communication services to the terminal, an optimal target base station is determined at the time of handover even in an environment where channel quality mismatch phenomenon and traffic amount asymmetry between downlink and uplink may occur between the terminal and the base station And consequently improve the performance of mobile communication services. It can have the effect that.

1 is a configuration diagram illustrating a communication system including a handover related device according to a preferred embodiment of the present invention.
2 is a control block diagram illustrating a handover related apparatus according to a preferred embodiment of the present invention.
3 is a flowchart of a communication system including a handover related device according to a preferred embodiment of the present invention.
4 is a flowchart illustrating an operation method of a handover related device according to a preferred embodiment of the present invention.
5 is an exemplary diagram for explaining a limit in a general handover method.

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

1 is a diagram illustrating a communication system including a handover related device according to a preferred embodiment of the present invention.

1, a communication system according to the present invention includes a connected base station 100 to which a terminal 10 and a terminal 10 are currently connected, and a plurality of adjacent base stations 1 and 2 adjacent to each other.

Here, FIG. 1 shows that the handover related apparatus according to the present invention and the connected base station to which the terminal 10 is currently connected are the same apparatus.

1, a handover related apparatus according to the present invention will now be described with reference to a connection base station 100. FIG.

However, this is merely an embodiment, and the handover related device according to the present invention may be configured as a separate device independent of the connected base station to which the terminal 10 is currently connected, so that it can interwork with the connected base station.

The connection base station 100 and the neighboring base stations 1 and 2 may be a macro cell base station (macro base station) or a variety of small cell base stations (small base stations) such as Femto, Pico, Micro, and Metro cells.

The terminal 10 is a terminal capable of entering a variety of small cells such as a macro cell, a Femto, a Pico, a Micro, and a Metro cell to use a communication service. The terminal 10 includes a handover performing function .

The terminal 10 can provide a communication service to a user by transmitting and receiving uplink and downlink data through the connected base station 100 to which the terminal 10 is connected.

The terminal 10 periodically measures the received signal to monitor channel quality associated with the downlink of the connected base station 100.

For example, in the case of the LTE communication system, the terminal 10 can measure the reception quality of the received signal (for example, RSRQ (Reference Signal Received Quality)), And the reception intensity of the received signal (for example, reference signal received power (RSRP)).

If the measured reception quality RSRQ or RSRP of the received signal related to the connected base station 100 is lower than the reference value, the terminal 10 determines that a reporting event for handover is generated, (E.g., RSRQ, RSRP) related to the downlink to the base station 100, and channel quality (e.g., RSRQ, RSRP) associated with the downlink to at least one neighbor base station, .

The terminal 10 transmits the quality measurement result of downlink-related reception signals to the access terminal 100 and the neighbor base stations 1 and 2, that is, downlink-related channel quality information To the connection base station 100.

Hereinafter, an existing handover scheme will be briefly described. In the conventional access terminal that receives downlink-related channel quality information as described above from the UE 10, only the downlink-related channel quality information (e.g., RSRQ, RSRP) The neighbor base station 1 is determined as a target base station for handover of the terminal 10 and the neighbor base station 1 is determined to be a target base station for handover to the neighbor base station 1, An associated handover request message will be transmitted.

When the neighbor base station 1 responds to the handover request message, the existing access terminal transmits a handover execution message to the terminal 10 so that the handover of the target base station, i.e., the neighbor base station 1, .

Referring to FIG. 5, a description will be given of the limitations of a conventional conventional handover method. For convenience of explanation, the situation of the communication system in which the macro base station 2 and the small base station 1 are mixed will be described.

Here, the boundary line a virtually indicates the boundary where the quality of the downlink signals from the macro base station 2 and the small base station 1 is the same. The boundary line b represents the position of the uplink path loss PL2 from the boundary line to the macro base station 2 and the uplink path loss PL1 from the small base station 1 to the same position.

It is assumed that the transmission power of the macro base station 2 is P2 and the transmission power of the small base station 1 is P1 (? P2). Assuming that the average interference amounts generated in the uplink in the macro base station 2 and the small base station 1 are substantially similar to each other in the case where P2 and P1 are the same (i.e., DELTA = 1 (0 dB) The boundary line a due to the quality and the boundary line b due to the channel quality of the uplink line have almost the same boundary line.

In general, there is a difference in the instantaneous channel characteristics of the uplink and the downlink due to differences in interference amounts in each base station, uplink / downlink fading characteristics, and frequency characteristics of uplink and downlink channels generated in the uplink However, the channel characteristics of the uplink and the downlink are almost similar in the average sense.

 However, the maximum transmission power of a typical macro base station is 20 W or more, and the transmission power of a small base station is about 100 mW. Therefore, in this case, the difference in transmission power between the macro base station 2 and the small base station 1 occurs more than 20 dB, and a large difference occurs between the boundary line a by the downlink and the boundary line b by the uplink.

In FIG. 5, it is preferable from the viewpoint of channel quality that terminals close to the small base station 1 on the basis of the downlink boundary a as in the UE a are connected to the small base station 1 in both the uplink and downlink directions. Similarly, UEs located close to the macro base station 2 on the basis of the uplink boundary line b, such as UE c, preferably maintain a connection state with the macro base station 2 in both uplink and downlink directions. However, when the UEs located between the boundary line a and the boundary line b, such as the UE b, are connected to the macro base station 2, the downlink is in a desirable connection state. However, in the uplink, . When the terminal is connected to the small base station 1, the opposite case occurs.

As described above, a discrepancy in channel quality may occur between the downlink and the uplink due to the difference in the base station transmission power depending on the type of the base station.

In a communication system based on packet switching such as LTE and WiMAX, data is transmitted through downlink and uplink according to the type of communication service (e.g., voice, Web browsing, FTP download, FTP upload, etc.) Asymmetry between uplink traffic and downlink traffic can occur when data amounts are different.

In this manner, in an environment where channel quality mismatch between downlink and uplink and traffic asymmetry between downlink and uplink may occur, handover is performed considering only the channel quality of the downlink as in the conventional handover scheme There is a limit in determining an optimal target base station.

Thus, when the handover performing apparatus, i.e., the access point base station 100 according to the present invention receives the downlink related channel quality information for the access terminal 100 and the neighbor base stations 1 and 2 from the terminal 10 as described above, And performs an optimal target base station determination process according to the present invention.

More specifically, the access point 100 measures at least one of the downlink-related data rate and the uplink-related data rate of the access point 100 itself.

Then, the access point base station 100 calculates the effective data rate for the connected base station 100 itself based on at least one of the measured downlink-related data rate and the uplink-related data rate.

In addition, the access point base station 100 confirms the decay rate required for estimating the data rate of the adjacent base station based on the data rate of the access point base station 100, for each of the neighboring base stations 1 and 2.

Here, the attenuation rate identified for each of the neighboring base stations 1 and 2 includes the downlink-related signal attenuation rate and the uplink-related signal attenuation rate predicted for each of the adjacent base stations 1 and 2 based on the access point base station 100, Related data rate and uplink-related signal attenuation rate may be calculated or predicted using the downlink-related channel quality information received from the terminal 10. [

Then, the access point base station 100 calculates an estimated data rate for each of the neighboring base stations 1 and 2 based on the effective data rate for the access point base station 100 itself and the decay rate of each of the neighboring base stations 1 and 2.

Based on the effective data rate for the connected base station 100 itself and the estimated data rate for the neighboring base stations 1 and 2, the connecting base station 100 determines whether the connection base station 100 or one of the adjacent base stations 1, Can be determined as the handover target base station of the terminal (10).

The serving base station 100 transmits a handover request message to the determined target base station, e.g., the neighbor base station 2, for the terminal 10, and when the neighbor base station 2 responds to the handover request message, The MS 10 performs a handover to the target BS, i.e., the neighbor BS 2.

In other words, unlike the conventional method of determining the target BS in consideration of only the downlink-related channel quality information received from the MS 10, the access point 100 as a handover related device according to the present invention includes the access point 100 Related data rate and uplink-related data rate measured in the uplink-related data rate and the downlink-related channel quality information received from the UE 10.

Hereinafter, the configuration of a handover related device according to the present invention will be described in more detail with reference to FIG. The handover related apparatus according to the present invention and the connected base station to which the terminal 10 is currently connected may be the same apparatus.

The handover related apparatus 100 according to the present invention includes a data rate measuring unit 120 for measuring at least one of a downlink related data rate and an uplink related data rate from a connected base station to which the terminal 10 is connected, An attenuation rate confirmation unit 130 for confirming an attenuation rate required for estimating a data rate of an adjacent base station based on a data rate of the access point 100 for each of at least one adjacent base station associated with the access point 10, Related data rate and the uplink-related data rate, a valid data rate check unit (140) for checking a valid data rate for a connected base station based on at least one of a data rate, an associated data rate, and the uplink- An estimated data rate determination unit 150 for determining an estimated data rate for the at least one neighbor base station based on the attenuation rate, A target base station determining unit for determining a base station of one of the connected base station and the at least one neighbor base station as a handover target base station of the terminal (10) based on the effective data rate for the neighbor base station and the estimated data rate for the at least one neighbor base station (160).

In addition, the handover related device 100 according to the present invention may further include a channel quality information receiving unit 110 for receiving downlink related channel quality information from the terminal 10. [

As described above, when the UE 10 confirms the occurrence of the reporting event for performing the handover, the UE 10 transmits the channel quality (e.g., RSRQ, RSRP) related to the downlink to the serving base station and at least one neighboring base station, I.e., downlink-related channel quality information to the access point.

The channel quality information receiving unit 110 receives the downlink related channel quality information provided from the terminal 10.

The data rate measuring unit 120 measures at least one of the downlink related data rate and the uplink related data rate from the connected base station to which the terminal 10 is connected.

More specifically, the data rate measurement unit 120 measures the maximum downlink data rate measured at the connected base station and the average downlink data rate for at least one terminal connected to the connected base station, , It is possible to measure the downlink related data rate.

For example, when the maximum downlink data rate measured at the connection base station is 50 Mbps and the average downlink data rate for at least one terminal connected to the connection base station is 5 Mbps, the data rate measuring unit 120 measures 5/50 0.1 can be measured as the downlink related data rate.

The data rate measuring unit 120 measures the uplink data rate based on the maximum uplink data rate measured at the connection base station and the average uplink data rate for at least one terminal connected to the connection base station during the specific data rate measurement interval, Link-related data rates can be measured.

For example, when the maximum uplink data rate measured at the connection base station is 60 Mbps and the average uplink data rate for at least one terminal connected to the connection base station is 6 Mbps, the data rate measuring unit 120 measures 6/60 0.1 can be measured as the uplink related data rate.

Here, the specific data rate measurement period may be a period in which the point of time when receiving the downlink related channel quality information from the terminal 10 is an end point and the point of time preceding the end point is a predetermined point in time .

The valid data rate check unit 140 checks the valid data rate for the connected base station based on at least one of the downlink related data rate and the uplink related data rate measured by the data rate measuring unit 120.

More specifically, the valid data rate check unit 140 determines whether or not the valid data rate is valid for the connected base station based on the downlink-related data rate to which the predetermined first weight is applied and the uplink-related data rate to which the predetermined second weight is applied The data rate can be calculated.

For example, the effective data rate check unit 140 can calculate the effective data rate for the connected base station based on Equation (1) below.

는 하향링크 관련 데이터속도,

는 상향링크 관련 데이터속도를 나타낸다.Where Ds is the effective data rate of the connected base station,? Is the first weight, (1 -?) Is the second weight,

A downlink-related data rate,

Indicates an uplink-related data rate.

Here, the first weight and the second weight are set to be larger than the second weight in the case of a communication service in which the amount of downlink data is larger than the amount of uplink data, according to the type of communication service provided to the terminal And if the amount of uplink data is more than the amount of downlink data, the second weight is preferably set to be larger than the first weight.

That is, the valid data rate check unit 140 checks the type of the communication service provided to the terminal 10, and when the type of the communication service is a communication service for which the amount of downlink data is greater than the amount of uplink data, 1 > is set to be larger than the second weight, and the effective data rate for the connected base station can be calculated according to the above-described equation (1). Alternatively, if the type of the communication service provided to the terminal 10 is a predetermined communication service in which the amount of uplink data is larger than the amount of downlink data, the valid data rate confirmation unit 140 may set the second weight to be larger than the first weight And the effective data rate for the connected base station can be calculated according to the above-described Equation (1).

The attenuation rate confirmation unit 130 confirms the decay rate required for estimating the data rate of the adjacent base station based on the data rate of the connected base station for each of at least one adjacent base station related to the terminal 10, do.

Here, it is preferable that the attenuation rate to be checked for each of the neighboring base stations 1 and 2 includes the downlink-related signal attenuation rate and the uplink-related signal attenuation rate predicted for each of the neighboring base stations 1 and 2 based on the connected base station.

That is, to describe the adjacent base station 1, the attenuation rate confirmation unit 130 confirms the downlink-related signal attenuation rate and the uplink-related signal attenuation rate predicted for the adjacent base station 1 on the basis of the connection base station.

It is preferable that the downlink related signal attenuation rate of the adjacent base station 1 is the received signal quality value of the adjacent base station 1 with respect to the received signal quality value of the connected base station identified in the downlink related channel quality information received from the terminal 10. [

In other words, the attenuation rate confirmation unit 130 uses the received signal quality value of the connected base station, that is, the received signal quality value of the adjacent base station 1, i.e. RSRQ, compared with the RSRQ, which is confirmed in the downlink related channel quality information received from the terminal 10 The downlink-related signal attenuation rate of the adjacent base station 1 can be confirmed according to Equation (2).

Here, RSRQs represents the received signal quality value of the connected base station, RSRQN, i represents the received signal quality value of the adjacent base station i (= 1), and can be ascertained from the downlink related channel quality information received from the terminal 10.

The uplink related signal attenuation rate of the neighbor base station 1 is preferably calculated using the received signal strength value of the neighbor base station 1 with respect to the received signal strength value of the connected base station received from the terminal 10.

In other words, the attenuation rate confirmation unit 130 uses the received signal strength value of the connected base station, that is, the received signal strength value of the neighbor base station 1, that is, RSRP, compared with the RSRP, which is confirmed in the downlink related channel quality information received from the terminal 10 The uplink related signal attenuation rate of the adjacent base station 1 can be calculated and confirmed according to the following equation (3).

는 단말(10)의 송신전력값,

와

는 각각 단말(10)로부터 접속기지국과 인접기지국i(=1)과의 상향링크 경로손실값, EPREs는 접속기지국의 송신전력값, EPREN,i는 인접기지국i(=1)의 송신전력값을 나타내며,

는 접속기지국에서 측정된 간섭량,

는 인접기지국i(=1)에서 측정된 간섭량을 나타내며, 이들은 기지국장치 관련 규격에 근거하여 해당 기지국장치로부터 획득하거나 추정할 수 있는 값들이다.Here, RSRPs represents the received signal strength value of the connected base station, RSRPN, i represents the received signal strength value of the neighbor base station i (= 1), and can be confirmed from the downlink related channel quality information received from the terminal 10. And,

Is the transmission power value of the terminal 10,

Wow

EPREs is the transmission power value of the connected base station, EPREN, i is the transmission power value of the adjacent base station i (= 1) Lt; / RTI &

Is the interference amount measured at the connection base station,

Represents the amount of interference measured at the neighbor base station i (= 1), which are values that can be acquired or estimated from the base station apparatus based on the base station apparatus-related standard.

The estimated data rate check unit 150 checks the effective data rate of the connected base station and the attenuation rate of each of the adjacent base stations 1 and 2 checked by the attenuation rate checking unit 130, Based on this, the estimated data rate for the neighboring base stations 1 and 2 is confirmed.

)와, 해당하는 상향링크 관련 신호감쇄율 및 기 설정된 제2가중치 중 적어도 하나를 적용한 상향링크 관련 데이터속도(

)를 기초로, 추정데이터속도를 계산할 수 있다. More specifically, the estimated data rate check unit 150 determines the estimated data rate using the downlink-related signal attenuation rate and the predetermined first weight that are applied to the at least one adjacent base station, that is, Link-related data rate (

Related uplink data rate (hereinafter referred to as " uplink-related data rate ") to which at least one of the corresponding uplink-

), The estimated data rate can be calculated.

For example, the estimated data rate determination unit 150 can calculate the estimated data rate for the neighboring base stations 1 and 2 based on Equation (4) below.

,

는 접속기지국에서 측정된 하향링크 관련 데이터속도 및 상향링크 관련 데이터속도,

는 인접기지국i(=1)의 하향링크 관련 신호감쇄율,

는 인접기지국i(=1)의 상향링크 관련 신호감쇄율을 나타낸다.Herein, the neighboring base station 1 is referred to as DN, i is the estimated data rate of the neighbor base station i (= 1),? Is the first weight, (1-?) Is the second weight,

,

Related data rate and uplink-related data rate measured at the connection base station,

Is the downlink-related signal attenuation rate of the adjacent base station i (= 1)

Represents the uplink-related signal attenuation rate of the adjacent base station i (= 1).

Here, the estimated data rate check unit 150 can calculate the estimated data rate of each adjacent base station according to the above-described equation (4) using the first weight and the second weight determined by the valid data rate check unit 140 have.

Based on the effective data rate for the connected base station and the estimated data rate for at least one neighboring base station, that is, the adjacent base stations 1 and 2, the target base station determining unit 160 determines the base station And determines it as the handover target base station of the terminal 10.

More specifically, the target base station determining unit 160 determines the maximum estimated data rate among the estimated data rates of the adjacent base stations 1 and 2, which are confirmed by the estimated data rate check unit 150, The handover of the terminal 10 can be prevented from being performed when the effective data rate of the connected base station is larger than the valid data rate of the base station that has been checked.

That is, when the effective data rate of the connected base station is higher than the estimated data rate of the adjacent base station 2, assuming that the estimated data rate of the adjacent base station 2 is the maximum among the estimated data rates of the adjacent base stations 1 and 2, It is most preferable to maintain the connection with the connection base station. Therefore, the target base station determination unit 160 can prevent the handover of the terminal 10 from being performed in this case.

The target base station determining unit 160 identifies the data rate having the maximum value among the effective data rate of the connected base station and the estimated data rate of the neighbor base stations 1 and 2, It can be decided as a base station.

That is, if the effective data rate of the connected base station is not greater than the estimated data rate of the neighbor base station 2, assuming that the estimated data rate of the adjacent base station 2 is the maximum among the estimated data rates of the neighboring base stations 1 and 2, Will be the data rate with the maximum value.

Accordingly, the target base station determination unit 160 can determine the base station having the maximum data rate, that is, the neighbor base station 2, as the target base station.

If the handover related apparatus 100 and the connection base station of the present invention are the same apparatus, the handover related apparatus 100, i.e., the access terminal 100, When the neighbor base station 2 responds to the handover request message, the MS 10 performs a handover to the target BS, that is, the neighbor BS 2, by transmitting a handover execution message to the MS 10 .

Meanwhile, if the handover related apparatus 100 of the present invention and the connection base station are configured as separate apparatuses, the handover related apparatus 100 of the present invention informs the connected base station that the neighbor base station 2 is determined to be the target base station, The serving base station transmits a handover request message to the target base station, for example, the neighbor base station 2, for the terminal 10, and when the neighbor base station 2 responds to the handover request message, So that the terminal 10 performs handover to the target base station, that is, the neighbor base station 2.

As described above, according to the handover related apparatus of the present invention, unlike the conventional method of determining the target BS by considering only the downlink-related channel quality information received from the MS, the downlink- The base station determines the target base station based on the data rate of the connected base station and neighbor base stations that are determined in consideration of the rate, the uplink-related data rate, and the downlink-related channel quality information received from the terminal, It is possible to determine an optimal target base station at the time of handover even in an environment where channel quality mismatch phenomenon and traffic amount asymmetry may occur between the downlink and uplink between the terminal and the base station by providing various types of communication services to the terminal, To improve the performance of mobile communication services It has an effect.

Hereinafter, an operation method of the handover related device according to the present invention will be described with reference to FIG. 3 to FIG.

Referring to FIG. 3, an overall operation method of a communication system including a handover related device according to a preferred embodiment of the present invention will be described below. Hereinafter, a handover related apparatus according to the present invention will be described with reference to FIG.

The terminal 10 can provide a communication service to the user by transmitting and receiving uplink and downlink data through the connected base station 100 to which the terminal 10 is connected (S10).

The terminal 10 periodically transmits the reception quality of the received signal (for example, RSRQ (Reference Signal Received Quality)) and the reception strength of the received signal (for example, RSRP (Reference Signal Received Power)).

If the measured reception quality RSRQ or RSRP of the received signal related to the connected base station 100 falls below the reference value, the terminal 10 determines that a reporting event for performing the handover is generated (S20 (E.g. RSRQ, RSRP) associated with the downlink to the connected base station 100, and measures the channel quality (e.g., RSRQ, RSRP) associated with the downlink to at least one neighboring base station, , RSRP) are measured (S30).

The terminal 10 transmits the quality measurement result of downlink-related reception signals to the access terminal 100 and the neighbor base stations 1 and 2, that is, downlink-related channel quality information To the connection base station 100 (S40).

Accordingly, when the handover performing apparatus, i.e., the access point 100, receives downlink-related channel quality information for the access point 100 and the neighboring base stations 1 and 2 from the terminal 10 as described above (S50 ), And performs an optimal target base station determination process according to the present invention.

More specifically, the access point 100 measures at least one of the downlink-related data rate and the uplink-related data rate of the access point 100 itself (S60).

The connection base station 100 calculates an effective data rate for the connected base station 100 based on at least one of the measured downlink-related data rate and the uplink-related data rate (S70).

In addition, the access point base station 100 confirms the decay rate required for estimating the data rate of the adjacent base station based on the data rate of the access point base station 100, for each of the neighboring base stations 1 and 2.

Here, the attenuation rate identified for each of the neighboring base stations 1 and 2 includes the downlink-related signal attenuation rate and the uplink-related signal attenuation rate predicted for each of the adjacent base stations 1 and 2 based on the access point base station 100, Related data rate and uplink-related signal attenuation rate may be calculated or predicted using the downlink-related channel quality information received from the terminal 10. [

The connection base station 100 calculates an estimated data rate for each of the neighboring base stations 1 and 2 based on the effective data rate for the connected base station 100 itself and the decay rate of each of the neighboring base stations 1 and 2 (S75).

Based on the effective data rate for the connected base station 100 itself and the estimated data rate for the neighboring base stations 1 and 2, the connecting base station 100 determines whether the connection base station 100 or one of the adjacent base stations 1, To the handover target base station of the terminal 10 (S80).

The serving base station 100 transmits a handover request message to the determined target base station, e.g., the neighbor base station 2, for the terminal 10, and when the neighbor base station 2 responds to the handover request message, The MS 10 performs a handover to the target BS, that is, the neighbor BS 2 (S90).

Hereinafter, an operation method of the handover related device according to the present invention will be described in more detail with reference to FIG.

The operation method of the handover related apparatus according to the present invention receives the downlink related channel quality information provided from the terminal 10 (S100).

The operation method of the handover related device according to the present invention measures at least one of the downlink related data rate and the uplink related data rate from the connected base station to which the terminal 10 is connected (S110).

A method of operating a handover related apparatus according to the present invention checks an effective data rate for a connected base station based on at least one of a downlink-related data rate and an uplink-related data rate measured by a connection base station (S120).

More specifically, a method of operating a handover related apparatus according to the present invention is a method for operating a handover related apparatus, based on a downlink-related data rate to which a predetermined first weight is applied and an uplink-related data rate to which a predetermined second weight is applied, Lt; / RTI > can be calculated.

For example, a method of operating a handover related device according to the present invention may calculate a valid data rate for a connected base station based on Equation 1 above

Here, the method of operating the handover related device according to the present invention is a method of confirming the type of communication service provided to the terminal 10 and determining whether the type of the communication service is a communication service , The first weight is set to be larger than the second weight, and the effective data rate for the connected base station can be calculated according to Equation (1).

Alternatively, a method of operating a handover related device according to the present invention is a method of operating a handover related device in a case where a type of communication service provided to the terminal 10 is a predetermined communication service in which the amount of uplink data is larger than the amount of downlink data, The effective data rate for the connected base station can be calculated according to the above-described equation (1).

The method of operating a handover related apparatus according to the present invention is a method for operating a handover related apparatus according to an embodiment of the present invention by calculating a data rate of a neighbor base station based on a data rate of a connected base station, The required attenuation factor is estimated (S125).

Here, it is preferable that the attenuation rate to be checked for each of the neighboring base stations 1 and 2 includes the downlink-related signal attenuation rate and the uplink-related signal attenuation rate predicted for each of the neighboring base stations 1 and 2 based on the connected base station.

In other words, referring to the adjacent base station 1, the method of operating the handover related apparatus according to the present invention confirms the downlink-related signal attenuation rate and the uplink-related signal attenuation rate predicted for the adjacent base station 1 based on the connection base station .

In other words, a method of operating a handover related apparatus according to the present invention is a method of operating a handover related apparatus according to an embodiment of the present invention, That is, RSRQ can be used to confirm the downlink-related signal attenuation rate of the adjacent base station 1 according to Equation (2).

A method of operating a handover related apparatus according to the present invention is a method of operating a handover related apparatus according to an embodiment of the present invention. RSRP, the uplink-related signal attenuation rate of the neighbor base station 1 can be calculated and confirmed according to Equation (3).

The operation method of the handover related device according to the present invention is based on the effective data rate of the connected base station determined in step S120 and the decay rate of each of the adjacent base stations, 2 < / RTI >

)와, 해당하는 상향링크 관련 신호감쇄율 및 기 설정된 제2가중치 중 적어도 하나를 적용한 상향링크 관련 데이터속도(

)를 기초로, 추정데이터속도를 계산할 수 있다. More specifically, the method of operating a handover related apparatus according to the present invention is a method for operating a handover related apparatus, comprising: receiving downlink related data, to which at least one of a downlink- speed(

Related uplink data rate (hereinafter referred to as " uplink-related data rate ") to which at least one of the corresponding uplink-

), The estimated data rate can be calculated.

For example, the operating method of the handover related apparatus according to the present invention can calculate the estimated data rate for the neighboring base stations 1 and 2 based on the above-described equation (4).

Here, the method of operating the handover related apparatus according to the present invention can calculate the estimated data rate of each neighbor BS according to Equation (4) using the first weight and the second weight determined in step S120.

A method of operating a handover related apparatus according to the present invention is a method for operating a handover related apparatus including a base station and a neighbor base station based on a valid data rate for a connected base station and an estimated data rate for at least one neighboring base station, And determines one base station as the handover target base station of the terminal 10.

More specifically, the method of operating a handover related device according to the present invention compares the maximum estimated data rate among the estimated data rates of the neighboring base stations 1 and 2 with the effective data rate of the base station (S140) If the effective data rate of the base station is larger, the handover of the terminal 10 may not be performed (S170).

That is, when the effective data rate of the connected base station is higher than the estimated data rate of the adjacent base station 2, assuming that the estimated data rate of the adjacent base station 2 is the maximum among the estimated data rates of the adjacent base stations 1 and 2, It is most preferable to maintain the connection with the connection base station. Therefore, the operation method of the handover related device according to the present invention can prevent the handover of the terminal 10 in this case.

A method of operating a handover related apparatus according to the present invention includes: confirming a data rate having a maximum value among an effective data rate of a connected base station and an estimated data rate of the neighboring base stations 1 and 2; The target base station can be determined as the target base station (S150).

That is, if the effective data rate of the connected base station is not greater than the estimated data rate of the neighbor base station 2, assuming that the estimated data rate of the adjacent base station 2 is the maximum among the estimated data rates of the neighboring base stations 1 and 2, Will be the data rate with the maximum value.

Accordingly, the method of operating the handover related apparatus according to the present invention can determine the base station having the maximum data rate, that is, the neighbor base station 2, as the target base station.

If the handover related device 100 and the connection base station of the present invention are one and the same, the method of operating the handover related device according to the present invention is a method of operating the handover related device according to the present invention, When the neighbor base station 2 responds to the handover request message, the MS 10 transmits a handover execution message to the MS 10 to perform handover to the target BS, that is, (S160).

Meanwhile, if the handover related apparatus 100 and the connection base station of the present invention are configured as separate apparatuses separate from each other, the method of operating the handover related apparatus according to the present invention notifies the access base station that the neighbor base station 2 is determined to be the target base station The serving base station transmits a handover request message to the determined target base station, for example, the neighbor base station 2, for the terminal 10, and when the neighbor base station 2 responds to the handover request message, (S160). In step S160, the MS 10 performs a handover to the target BS, i.e., the neighbor BS2.

As described above, according to the method of operating the handover related apparatus according to the present invention, unlike the existing method of determining the target BS considering only the downlink related channel quality information received from the MS, Determining a target base station based on a data rate of a connected base station and neighbor base stations that are confirmed in consideration of the downlink related data rate, the uplink related data rate, and the downlink related channel quality information received from the terminal, As the base station is concentrated and provides various types of communication services to the terminal, an optimal target base station is determined at the time of handover even in an environment where channel quality mismatch phenomenon and traffic amount asymmetry between downlink and uplink may occur between the terminal and the base station As a result, the performance of mobile It has an effect that it can be erased.

A method of operating a handover related apparatus according to an embodiment of the present invention may be implemented in the form of a program command that can be executed through various computer means and recorded in a computer readable medium. The computer-readable medium may include program instructions, data files, data structures, and the like, alone or in combination. The program instructions recorded on the medium may be those specially designed and constructed for the present invention or may be available to those skilled in the art of computer software. Examples of computer-readable media include magnetic media such as hard disks, floppy disks and magnetic tape; optical media such as CD-ROMs and DVDs; magnetic media such as floppy disks; Magneto-optical media, and hardware devices specifically configured to store and execute program instructions such as ROM, RAM, flash memory, and the like. Examples of program instructions include machine language code such as those produced by a compiler, as well as high-level language code that can be executed by a computer using an interpreter or the like. The hardware devices described above may be configured to operate as one or more software modules to perform the operations of the present invention, and vice versa.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, but, on the contrary, It will be understood by those skilled in the art that various changes in form and details may be made therein without departing from the spirit and scope of the invention as defined by the appended claims.

According to the handover related device and the method of operating the handover related device according to the present invention, since various types of base stations are concentrated in the same area and various types of communication services are provided to the terminal, the downlink and uplink It is possible to determine an optimal target base station at the time of handover even in an environment where channel quality mismatching phenomenon and traffic amount asymmetry may occur, and as a result, performance of mobile communication service can be improved as a result, Accordingly, it is not only the use of the related technology, but also the possibility of commercialization because it is possible to carry out the application or the operation of the device which is applicable, and to be practically and practically possible.

100: Handover related device
110: channel quality information receiving unit 120: data rate measuring unit
130: Decay rate checker 140: Valid data rate checker
150: Estimated data rate verifying unit 160: Target base station determining unit

Claims (13)

A data rate measuring unit for measuring at least one of a downlink related data rate and an uplink related data rate from a connected base station to which the terminal is connected;
A valid data rate confirmation unit for confirming a valid data rate for the connection base station based on at least one of the downlink related data rate and the uplink related data rate;
An estimated data rate confirmation unit for confirming an estimated data rate for at least one neighbor base station based on the valid data rate; And
And a target base station determining unit determining a handover target base station of the terminal based on a valid data rate for the connected base station and an estimated data rate for the at least one neighbor base station;
The target base station determining unit may determine,
If the estimated data rate for a particular neighboring base station is the largest among the estimated data rates for the at least one neighboring base station and the effective data rate for the connected base station is greater than the estimated data rate for the particular neighboring base station, And determines the specific neighbor base station as the target base station if the effective data rate for the connected base station is smaller than the estimated data rate for the specific neighbor base station,
The valid data rate check unit may include:
Wherein the base station calculates the effective data rate based on the downlink related data rate to which the predetermined first weight is applied and the uplink related data rate to which the predetermined second weight is applied, Over related devices. The method according to claim 1,
Wherein the data rate measuring unit comprises:
Measuring a downlink related data rate based on a maximum downlink data rate measured at the connection base station and an average downlink data rate for at least one terminal connected to the connection base station during a specific data rate measurement interval,
Related data rate based on a maximum uplink data rate measured at the connection base station and an average uplink data rate for at least one terminal connected to the connection base station during a specific data rate measurement interval. Handover related devices. delete The method according to claim 1,
Further comprising an attenuation rate confirmation unit for confirming an attenuation rate required for estimating the data rate of the adjacent base station based on the data rate of the connection base station for each of at least one neighbor base station associated with the terminal,
The determined attenuation rate for each of the at least one neighbor base stations is determined by:
And a downlink-related signal attenuation rate and an uplink-related signal attenuation rate predicted for each of the at least one neighbor base station based on the connection base station. 5. The method of claim 4,
Wherein the estimated data rate confirmation unit comprises:
Related signal rate and a predetermined second weight for each of the at least one neighbor base station, the downlink-related data rate to which at least one of the downlink-related signal attenuation rate and the predetermined first weight is applied, Related data rate based on the uplink-related data rate to which the handover is applied. 6. The method according to claim 1 or 5,
Wherein the first weight and the second weight are < RTI ID = 0.0 >
The first weight is set to be larger than the second weight when the amount of downlink data is larger than the amount of uplink data according to the type of the communication service provided to the terminal and the amount of uplink data is larger than the amount of downlink data And the second weight is set to be larger than the first weight in the case of a communication service. The method according to claim 4 or 5,
The downlink-related signal attenuation rate and the uplink-related signal attenuation rate of a specific neighbor base station among the at least one neighbor base station,
A quality of reception signal quality value of the specific neighbor base station or a reception signal strength value of the connection base station compared with a reception signal quality value of the connection base station, which is confirmed in the downlink related channel quality information received from the terminal, Value of the handover request message. A data rate measuring step of measuring at least one of a downlink-related data rate and an uplink-related data rate from a connection base station connected to the terminal;
Determining a valid data rate for the connection base station based on at least one of the downlink-related data rate and the uplink-related data rate;
Determining an estimated data rate for at least one neighbor base station based on the valid data rate; And
Determining a target base station as a handover target base station of the terminal based on a valid data rate for the connected base station and an estimated data rate for the at least one neighbor base station;
The target base station determining step may include:
If the estimated data rate for a particular neighboring base station is the largest among the estimated data rates for the at least one neighboring base station and the effective data rate for the connected base station is greater than the estimated data rate for the particular neighboring base station, And determines the specific neighbor base station as the target base station if the effective data rate for the connected base station is smaller than the estimated data rate for the specific neighbor base station,
The valid data rate checking step includes:
Wherein the base station calculates the effective data rate based on the downlink related data rate to which the predetermined first weight is applied and the uplink related data rate to which the predetermined second weight is applied, Over-related device. delete 9. The method of claim 8,
Further comprising an attenuation rate confirmation step of confirming, for each of at least one neighbor base station associated with the terminal, an attenuation rate necessary for estimating a data rate of the adjacent base station based on the data rate of the connection base station;
The determined attenuation rate for each of the at least one neighbor base stations is determined by:
Related signal damping rate and uplink-related signal damping rate for each of the at least one neighbor base station based on the connection base station. 11. The method of claim 10,
Wherein the step of estimating the estimated data rate comprises:
Related signal rate and a predetermined second weight for each of the at least one neighbor base station, the downlink-related data rate to which at least one of the downlink-related signal attenuation rate and the predetermined first weight is applied, Related data rate based on the uplink-related data rate to which the handover-related data rate is applied. The method according to claim 8 or 11,
Wherein the first weight and the second weight are < RTI ID = 0.0 >
The first weight is set to be larger than the second weight when the amount of downlink data is larger than the amount of uplink data according to the type of the communication service provided to the terminal and the amount of uplink data is larger than the amount of downlink data And the second weight is set to be larger than the first weight in the case of a communication service. The method according to claim 10 or 11,
The downlink-related signal attenuation rate and the uplink-related signal attenuation rate of a specific neighbor base station among the at least one neighbor base station,
A quality of reception signal quality value of the specific neighbor base station or a reception signal strength value of the connection base station compared with a reception signal quality value of the connection base station, which is confirmed in the downlink related channel quality information received from the terminal, Value of the handover-related device.

Images