KR20180079638A - Access method of communication node in network - Google Patents

Abstract

A method of connecting a communication node in a network is disclosed. An operation method of a terminal comprises the steps of: receiving, from a first base station system, information including an indicator indicating whether the first base station is a mobile base station or a fixed base station, a cell selection timer, a cell selection priority and a transmission delay time; determining whether to connect to the first base station in consideration of the cell selection timer, the cell selection priority, and the transmission delay time when the indicator indicates that the first base station is the mobile base station; and accessing the first base station after a period indicated by the cell selection timer. Accordingly, the performance of the communication network can be improved.

Description

[0001] ACCESS METHOD OF COMMUNICATION NODE IN NETWORK [0002]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a connection method of a communication node, and more particularly, to a connection method performed in a mobile network and a mobile station in a cellular network.

A cellular network may include a macro base station, a terminal, and the like. In a cellular network, a terminal typically can send and receive data units via a macro base station. For example, if there is a data unit to be transmitted to the second terminal, the first terminal can generate a message including a data unit to be transmitted to the second terminal, and transmit the generated message to the first macro base station Lt; / RTI > The first macro base station can receive the message from the first terminal and confirm that the destination of the received message is the second terminal.

The first macro base station can transmit a message to the second macro base station to which the second terminal, which is the confirmed destination, belongs. The second macro base station can receive the message from the first macro base station and confirm that the destination of the received message is the second terminal. And the second macro base station can transmit the message to the second terminal, which is the confirmed destination. The second terminal can receive the message from the second macro base station and obtain the data unit contained in the received message.

On the other hand, a high quality communication service may not be provided to a terminal located in a city center or a traffic dense region in a cellular network. To solve this problem, a small base station can be introduced into a cellular network. The small base station can be located in an inner city, a traffic dense region, an edge region of a macro base station, or the like. In addition, the small base station may be located in a mobile means (e.g., bus, subway, train, etc.). A small base station located on the mobile means may be referred to as a "mobile base station ".

According to the movement characteristics of the mobile station, a handover procedure (or a cell selection procedure, a cell reselection procedure) between the mobile station and the terminal can be performed frequently. For example, when the mobile station is searched, the mobile station can perform the connection procedure with the searched mobile station. That is, when the channel quality between the mobile station and the mobile station is equal to or greater than a preset threshold value, a handover procedure (or a cell selection procedure, a cell reselection procedure) from the current base station to the mobile station can be performed. Thereafter, the channel quality between the mobile station and the mobile station may become less than a predetermined threshold value according to the movement of the mobile station. In this case, the handover procedure (or the cell selection procedure, the cell reselection procedure ) Can be performed. That is, the terminal can perform a connection procedure with another base station.

The mobile base station may also be connected to a core network via a wireless link (e.g., a wireless backhaul, a wireless front hole, or a wireless xhole). In this case, a transmission delay may occur between the mobile base station and the core network.

In order to solve the above problems, an object of the present invention is to provide a connection method between a mobile station and a mobile station.

According to another aspect of the present invention, there is provided a method of operating a terminal in a communication network, the method comprising: receiving an indicator indicating whether the first base station corresponds to a mobile station or a fixed base station, a cell selection timer, Receiving, from the first base station, system information including the cell selection timer, the cell selection priority, and the transmission delay time when the indicator indicates that the first base station is the mobile station Determining whether to connect to the first base station and connecting to the first base station after a period indicated by the cell selection timer when connection between the terminal and the first base station is possible.

Here, the transmission delay time may indicate a difference between a transmission time through the mobile station connected to the core network and a transmission time through the fixed base station connected to the core network by a wired link by a wireless link.

Here, the cell selection priority may be set differently for the mobile station and the fixed base station, or may be differently set for each transmission delay time.

Here, if a second base station having a cell selection priority higher than the cell selection priority of the first base station is not searched for during a period indicated by the cell selection timer, the connection between the terminal and the first base station is possible .

If the transmission delay time is less than a preset delay threshold, it can be determined that the connection between the subscriber station and the first base station is possible. If the transmission delay time is equal to or greater than the predetermined delay threshold value, It can be determined that the connection between the first base stations is impossible.

Here, the method of operating the terminal may further include performing a communication service satisfying the transmission delay time through the first base station after the terminal is connected to the first base station.

Here, the method of operating the terminal may further include measuring an RTD through the first base station after the terminal is connected to the first base station.

Here, when the communication network is a cellular network, the system information may be received through at least one of SIB and MIB.

Here, when the communication network is a wireless LAN, the system information may be received through at least one of a probe response frame and a beacon frame.

According to another aspect of the present invention, there is provided a method of operating a first base station in a communication network, the method comprising: receiving an indicator indicating a mobile station, a cell selection timer, a cell selection priority, And transmitting the system information, wherein the indicator, the cell selection timer, the cell selection priority, and the transmission delay time are transmitted from the terminal receiving the system information to the terminal, And is used to determine whether or not the first base station is connected.

Here, the transmission delay time may indicate a difference between a transmission time through the mobile station connected to the core network and a transmission time through a fixed base station connected to the core network by a wired link.

Here, the cell selection priority may be set differently for the mobile station and the fixed base station, or may be differently set for each transmission delay time.

Here, when the communication network is a cellular network, the system information may be transmitted through at least one of the SIB and the MIB.

Here, when the communication network is a wireless LAN, the system information may be transmitted through at least one of a probe response frame and a beacon frame.

According to another aspect of the present invention, there is provided a terminal configured as a communication network, the terminal including a processor and a memory storing at least one instruction executed through the processor, From the first base station, system information including an indicator indicating whether the mobile station is a mobile station or a fixed base station, a cell selection timer, a cell selection priority, and a transmission delay time, The mobile station determines whether to connect to the first base station in consideration of the cell selection timer, the cell selection priority, and the transmission delay time, and when the connection between the terminal and the first base station is possible, After the interval indicated by the cell selection timer, the first base station It is carried out to fall.

Here, the transmission delay time may indicate a difference between a transmission time through the mobile station connected to the core network and a transmission time through the fixed base station connected to the core network by a wired link by a wireless link.

Here, if a second base station having a cell selection priority higher than the cell selection priority of the first base station is not searched for during a period indicated by the cell selection timer, the connection between the terminal and the first base station is possible .

If the transmission delay time is less than a preset delay threshold, it can be determined that the connection between the terminal and the first base station is possible. If the transmission delay time is equal to or greater than the predetermined delay threshold value, It can be determined that connection between one base station is impossible.

Here, the at least one command may be further executed to perform a communication service satisfying the transmission delay time through the first base station after the terminal is connected to the first base station.

Here, the at least one command may be further executed to measure the RTD via the first base station after the terminal is connected to the first base station.

According to the present invention, a mobile station can transmit system information including an indicator indicating a mobile station, a cell selection timer, a cell selection priority, a transmission delay time, and the like. The UE can determine whether to access the mobile station based on system information (e.g., an indicator, a cell selection timer, a cell selection priority, and a transmission delay time) received from the mobile station. According to this, frequent execution of the handover procedure (or the cell selection procedure and the cell reselection procedure) can be prevented, and the communication service can be performed in consideration of the transmission delay time of the mobile station. Thus, the performance of the communication network can be improved.

1 is a conceptual diagram showing an embodiment of a communication network.
2 is a block diagram illustrating one embodiment of a communications node included in a communications network.
3 is a flowchart showing an embodiment of a connection method between base station terminals.

While the invention is susceptible to various modifications and alternative forms, specific embodiments thereof are shown by way of example in the drawings and will herein be described in detail. It should be understood, however, that the invention is not intended to be limited to the particular embodiments, but includes all modifications, equivalents, and alternatives falling within the spirit and scope of the invention.

The terms first, second, etc. 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 a second component, and similarly, the second component may also be referred to as a first component. And / or < / RTI > includes any combination of a plurality of related listed items or any of a plurality of related listed items.

It is to be understood that when an element is referred to as being "connected" or "connected" to another element, it may be directly connected or connected to the other element, . On the other hand, when an element is referred to as being "directly connected" or "directly connected" to another element, it should be understood that there are no other elements in between.

The terminology used in this application is used only to describe a specific embodiment and is not intended to limit the invention. The singular expressions include plural expressions unless the context clearly dictates otherwise. In the present application, the terms "comprises" or "having" and the like are used to specify that there is a feature, a number, a step, an operation, an element, a component or a combination thereof described in the specification, But do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, or combinations 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 to which this invention belongs. Terms such as those defined in commonly used dictionaries should be interpreted as having a meaning consistent with the meaning in the context of the relevant art and are to be interpreted in an ideal or overly formal sense unless explicitly defined in the present application Do not.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. In order to facilitate the understanding of the present invention, the same reference numerals are used for the same constituent elements in the drawings and redundant explanations for the same constituent elements are omitted.

1 is a conceptual diagram showing an embodiment of a communication network.

1, a communication network includes a mobility management entity (MME) 101, a serving gateway (S-GW) 102, a hub 103, macro base stations 110 and 120, 140-1, 140-2, 140-3, 140-4, 140-5, 140-6, 140-7, 140-7, 140-1, 140-2, 8, 140-9), and the like. The MME 101 and the S-GW 102 may be core networks. In addition, the MME 101 and the S-GW 102 may be referred to as "MME / S-GW ". Each of the macro base stations 110 and 120 may be connected to a core network (e.g., MME 101, S-GW 102) via a wired backhaul. The small base stations 111, 112, 121 and 122 may be located in an edge region, a traffic concentration region, or the like among the macro cells formed by the macro base stations 110 and 120.

The first macro base station 110 can form macro cells and the macro cells of the first macro base station 110 include the small base stations 111, 112 and 121 and the terminals 140-1, 140-2 and 140 -3, 140-4, 140-5, 140-6, and so on. For example, each of the terminals 140-2, 140-3, and 140-4 can access the first macro base station 110 and perform communication through the first macro base station 110. [ Each of the small base stations 111 and 112 may be connected to the first macro base station 110 and in this case the first macro base station 110 may control the operation of each of the small base stations 111 and 112. Each of the small base stations 111 and 112 may operate in the same frequency band as the first macro base station 110 or may operate in a frequency band different from that of the first macro base station 110. [

Here, each of the small base stations 111 and 112 may be connected to the first macro base station 110 via a wired link (for example, an X2 interface). That is, each of the small base stations 111 and 112 may be connected to the core network (for example, the MME 101 and the S-GW 102) through the first macro base station 110. Alternatively, each of the small base stations 111 and 112 may not be connected to the first macro base station 110, in which case each of the small base stations 111 and 112 may be connected to a core network (e.g., MME 101, S-GW 102).

The first small base station 111 may form a small cell and the first terminal 140-1 or the like may be located in a small cell of the first small base station 111. [ For example, the first terminal 140-1 may connect to the first small base station 111 and may perform communication through the first small base station 111. [ The second small base station 112 may form a small cell and the fifth terminal 140-5 or the like may be located in a small cell of the second small base station 112. [ For example, the fifth terminal 140-5 may connect to the second small base station 112, and may perform communication via the second small base station 112. [

The second macro base station 120 may form a macro cell and the macro cells of the second macro base station 120 may include small base stations 121 and 122 and terminals 140-4 and 140-6 and 140-7 , 140-8, 140-9), and the like. For example, each of the terminals 140-7 and 140-8 can access the second macro base station 120 and perform communication through the second macro base station 120. [ Each of the small base stations 121 and 122 may be connected to the second macro base station 120 and in this case the second macro base station 120 may control the operation of each of the small base stations 121 and 122. Each of the small base stations 121 and 122 may operate in the same frequency band as the second macro base station 120 or may operate in a frequency band different from that of the second macro base station 120. [

Here, each of the small base stations 121 and 122 may be connected to the second macro base station 120 via a wired link (for example, an X2 interface). That is, each of the small base stations 121 and 122 may be connected to the core network (for example, the MME 101 and the S-GW 102) through the second macro base station 120. Alternatively, each of the small base stations 121 and 122 may not be connected to the second macro base station 120, in which case each of the small base stations 121 and 122 may be connected to a core network (e.g., MME 101, S-GW 102).

The third small base station 121 can form a small cell and the sixth terminal 140-6 or the like can be located in a small cell of the third small base station 121. [ For example, the sixth terminal 140-6 may connect to the third small base station 121, and may perform communication through the third small base station 121. The fourth small base station 122 may form a small cell and the ninth terminal 140-9 or the like may be located in a small cell of the fourth small base station 122. [ For example, the ninth terminal 140-9 can connect to the fourth small base station 122 and can perform communication through the fourth small base station 122. [

On the other hand, each of the macro base stations 110 and 120 and the small base stations 111, 112, 121 and 122 may be referred to as a "fixed base station" The mobile base station 130 may be located in a mobile means (e.g., a bus, a subway, a train, etc.) and may move as the mobile means moves. The mobile base station 130 may be connected to the hub 103 via a wireless link (e.g., a wireless backhaul, a wireless front hole, a wireless x-hole). Hub 103 may be connected to a core network (e.g., MME 101, S-GW 102) via a wired backhaul or wireless link. The mobile station 130 may form a mobile cell and may communicate with a terminal located within the mobile cell. The mobile base station 130 may also be coupled to the base station 130 via a cellular communication (e.g., LTE (Long Term Evolution), LTE-A, 5G, etc. protocol, WiBro, wireless area local network wireless personal area network) protocol.

The mobile base station 130 can move along the movement path. When the mobile station 130 is located in the path P1, the fifth terminal 140-5 may be located in the mobile cell formed by the mobile station 130. [ In this case, the fifth terminal 140-5 may connect to one of the first macro base station 110, the second small base station 112, and the mobile station 130. The fifth terminal 140-5 may perform communication through the mobile station 130 when the mobile station 130 is connected to the mobile station 130-1. For example, if it is determined that the user of the fifth terminal 140-5 has boarded the mobile means on which the mobile terminal 130 is located, the fifth terminal 140-5 can access the mobile terminal 130 .

When the mobile station 130 is located at P2 in the movement path, the seventh terminal 140-7 may be located in the mobile cell formed by the mobile station 130. [ In this case, the seventh MS 140-7 can connect to one of the second macro base station 120 and the mobile station 130. [ The seventh terminal 140-7 can perform communication through the mobile station 130 when the mobile station 130 is connected to the seventh terminal 140-7. For example, if it is determined that the user of the seventh terminal 140-7 has boarded the mobile means on which the mobile station 130 is located, the seventh terminal 140-7 can access the mobile station 130 .

When the mobile base station 130 is located at P3 in the movement path, the ninth terminal 140-9 may be located in the mobile cell formed by the mobile base station 130. [ In this case, the ninth terminal 140-9 may connect to one of the second macro base station 120, the fourth small base station 122, and the mobile station 130. The ninth terminal 140-9 may perform communication through the mobile base station 130 when the ninth terminal 140-9 is connected to the mobile base station 130. [ For example, if it is determined that the user of the ninth terminal 140-9 has boarded the mobile means on which the mobile base station 130 is located, the ninth terminal 140-9 can access the mobile base station 130 .

Meanwhile, the communication network described above can support cellular communication (e.g., LTE, LTE-A, 5G) protocol, WiBro protocol, WLAN protocol, WPAN protocol, and the like. To support a high data rate, the communication network may operate in the very high frequency (mmWave) band (e.g., 30 GHz to 300 GHz). When communication is performed in the very high frequency band, the path loss can be increased and the transmission distance can be reduced. In order to solve this problem, the communication network may employ a beamforming technique (e.g., an analog beamforming technique), a massive multiple input multiple output (MIMO) technique, a full dimensional (MIMO) Technology, array antenna technology, and large scale antenna technology.

In addition, the communication network may also be a wireless cellular network, such as an advanced small cell technology, cloud RAN (radio access network) technology, ultra dense network technology, wireless backhaul, wireless front hall, wireless X- device technology, mobile network technology, cooperative communication technology, CoMP (coordinated multi-points) technology, and interference cancellation technology. In addition, the communication network can be classified into an advanced coding modulation (ACM), a frequency quadrature amplitude modulation (FQAM), a sliding window superposition coding (SWSC), a filter bank multi carrier (FBMC), a non orthogonal multiple access (NOMA) ) Can be supported.

Each of the macro base stations 110 and 120 included in the communication network may be a NodeB, an eNodeB, an access point, a base band unit (BBU), or the like. Each of the small base stations 111, 112, 121 and 122 and the mobile base station 130 included in the communication network may be a femto base station, a relay, a remote radio head (RRH), or the like.

2 is a block diagram illustrating one embodiment of a communications node included in a communications network.

2, the communication node 200 includes the MME 101, the S-GW 102, the hub 103, the macro base stations 110 and 120, the small base stations 111 and 112 , 121 and 122, a mobile station 130, and terminals 140-1, 140-2, 140-3, 140-4, 140-5, 140-6, 140-7, 140-8, and 140-9 ) And the like. The communication node 200 may include at least one processor 210, a memory 220, and a transceiver 230 for communicating with a communication network. The communication node 200 may further include an input interface device 240, an output interface device 250, a storage device 260, and the like. Each component included in the communication node 200 may be connected by a bus 270 and communicate with each other.

The processor 210 may execute program commands stored in the memory 220 and / or the storage device 260. Processor 210 may refer to a central processing unit (CPU), a graphics processing unit (GPU), or a dedicated processor on which methods in accordance with the present invention are performed. The memory 220 and the storage device 260 may be composed of a volatile storage medium and / or a non-volatile storage medium. For example, the memory 220 may be comprised of a read only memory (ROM) and / or a random access memory (RAM).

Next, connection methods between the base station and the terminal will be described. Even if a method (e.g., transmission or reception of a message) to be performed at a first communication node among the communication nodes is described, the corresponding second communication node can perform a method corresponding to the method performed at the first communication node For example, receiving or transmitting a message). That is, when the operation of the terminal is described, the corresponding base station can perform an operation corresponding to the operation of the terminal. Conversely, when the operation of the base station is described, the corresponding terminal can perform an operation corresponding to the operation of the base station.

3 is a flowchart showing an embodiment of a connection method between base station terminals.

Referring to FIG. 3, the communication network may include an MME / S-GW, a fixed base station, a mobile station, a terminal, and the like. The MME / S-GW may be the same as or similar to the MME 101 and the S-GW 102 shown in FIG. The fixed base station may be the same as or similar to each of the macro base stations 110 and 120 and the small base stations 111, 112, 121 and 122 shown in FIG. For example, a fixed base station may be connected to the MME / S-GW via a wired backhaul. The mobile base station may be similar to the mobile base station 130 shown in FIG. For example, the mobile base station may be connected to the MME / S-GW via a wireless link (e.g., a wireless backhaul, a wireless front hall, a wireless x-hole). In addition, the mobile base station can support a cellular communication protocol, a WiBro protocol, a WLAN protocol, a WPAN protocol, and the like. The terminal may be the same as or different from each of the terminals 140-1, 140-2, 140-3, 140-4, 140-5, 140-6, 140-7, 140-8, Can be similar.

First, a setup procedure of the mobile station can be performed. For example, the MME / S-GW may generate configuration information for the mobile station. The configuration information includes an identifier of a mobile station, an indicator indicating whether the corresponding base station corresponds to a mobile station or a fixed base station (hereinafter referred to as a "mobile / fixed indicator"), a cell selection timer, A cell selection priority, a transmission delay time, operation frequency information, synchronization information, and the like.

The move / fix indicator can be indicated by a specific bit. For example, a specific bit set to "0 " may indicate that the type of the base station is a fixed base station, and a specific bit set to" 1 " Alternatively, a specific bit set to "0 " may indicate that the type of the corresponding base station is the mobile base station, and a specific bit set to" 1 " Alternatively, a separate mobile cell ID may be set instead of the mobile / fixed indicator, and the mobile cell ID may indicate that the corresponding base station is the mobile base station. The MME / S-GW can allocate a mobile cell ID to the mobile station, and the mobile station can perform communication using the mobile cell ID. Here, the mobile cell ID can be identified by a synchronization signal (for example, a primary synchronization signal (PSS), a secondary synchronization signal (SSS)) transmitted by the mobile station.

The cell selection timer may indicate a waiting interval for connection to the mobile station. For example, the UE can access the discovered mobile BS when the mobile BS is searched. After that, the mobile station may not be able to search for the mobile station as it moves. In this case, the UE must perform a handover procedure (or a cell selection procedure, a cell reselection procedure) from the mobile station 13 to another base station, and accordingly, the handover procedure (or the cell selection procedure, ) Is frequently performed. In order to solve this problem, the mobile station can access the mobile station after the waiting period indicated by the cell selection timer of the mobile station.

The cell selection timer can be set variously. For example, the cell selection timer may be set to 7 seconds, 10 seconds, 20 seconds, 30 seconds, and so on. Further, the cell selection timer can be set based on the movement characteristics of the mobile station. For example, the cell selection timer may be set to a time at which the mobile means in which the mobile station is located stays at the station (or station).

The transmission delay time may indicate the difference between the transmission time through the mobile base station connected to the MME / S-GW by the wireless link and the transmission time through the fixed base station connected to the MME / S-GW by the wired backhaul. The MME / S-GW can measure the transmission delay time by performing a ping command. Here, the transmission time through the mobile base station indicates from the transmission time at which the MME / S-GW transmits the data unit to the mobile station to the reception time at which the MME / S-GW receives the reception response for the data unit from the mobile station . Alternatively, the transmission time through the mobile BS indicates the time from the transmission of the data unit to the MME / S-GW to the reception of the reception response to the data unit from the MME / S-GW .

The transmission time through the fixed base station may indicate from the transmission time at which the MME / S-GW transmits the data unit to the fixed base station to the reception time at which the MME / S-GW receives the reception response for the data unit from the fixed base station . Alternatively, the transmission time through the fixed base station indicates from the transmission time of the data unit to the MME / S-GW by the fixed base station to the reception time of the reception of the reception response to the data unit from the MME / S-GW .

The cell selection priority may indicate the connection priority. For example, when a plurality of base stations are searched, the terminal can perform the connection procedure with the base station having the highest cell selection priority among the searched base stations. In addition, the terminal can determine an additional timer corresponding to the cell selection priority, and can connect to the mobile station after the waiting period indicated by "cell selection timer plus additional timer ". The higher the cell selection priority is, the more the timer can be set to a relatively small value, and the lower the cell selection priority, the more the timer can be set to a relatively larger value. The cell selection priority can be set according to the type of the base station. The cell selection priority of the fixed base station may be set higher than the cell selection priority of the mobile station. For example, the cell selection priority of the fixed base station may be set to "0 ", and the cell selection priority of the mobile station may be set to" 1 ".

Alternatively, the cell selection priority may be set according to the transmission delay time of each of the mobile stations. The cell selection priority of the mobile station having the shortest transmission delay time among the mobile stations can be set to the highest and the cell selection priority of the mobile station having the longest transmission delay time among the mobile stations can be set to the lowest have. For example, the MME / S-GW can set the cell selection priority of each of the mobile stations based on the mapping table shown in Table 1 below.

In addition, the MME / S-GW can set resources for the mobile station. For example, the MME / S-GW can set resources for uplink transmission and resources for downlink transmission between a mobile station and a mobile station. In addition, the MME / S-GW can set resources for uplink transmission and resources for downlink transmission between the mobile station and the MME / S-GW.

The MME / S-GW may transmit setting information and resource information to the mobile station (S300). Meanwhile, when the mobile station can set the movement / fix indicator, the cell selection timer, the cell selection priority and the transmission delay time among the setting information, the MME / S-GW moves setting information excluding the information set by the mobile station To the base station.

The mobile base station can receive configuration information and resource information from the MME / S-GW, and can operate based on the received configuration information and resource information. In addition, when the setting information received from the MME / S-GW does not include the movement / fix indicator, the cell selection timer, the cell selection priority, and the transmission delay time, A fixed indicator, a cell selection timer, a cell selection priority, and a transmission delay time.

1, the mobile station is the mobile station 130 shown in FIG. 1, and the terminal is the seventh terminal 140-7 shown in FIG. 1, The connection procedure between the mobile station 130 and the seventh terminal 140-7 will be described.

The second macro base station 120 may transmit synchronization signals (e.g., PSS, SSS) and system information (S301). Since the seventh MS 140-7 is located within the coverage of the second macro BS 120, the seventh MS 140-7 can receive the synchronization signal from the second macro BS 120, 120). In addition, the seventh terminal 140-7 can confirm the cell ID of the second macro base station 120 based on the synchronization signal. For example, if the cell ID of the second macro base station 120 is not the mobile cell ID, the seventh MS 140-7 can determine that the type of the second macro base station 120 is a fixed base station. Thereafter, the seventh MS 140-7 can receive the system information from the second macro base station 120 and can perform the connection procedure with the second macro base station 120 based on the system information (S302) . That is, the seventh MS 140-7 may be camped on the second macro base station 120. Since the system information received from the second macro base station 120 does not include the movement / fix indicator, the cell selection timer, the cell selection priority, and the transmission delay time, the seventh terminal 140-7 transmits the movement / It is possible to perform the connection procedure with the second macro base station 120 without considering the selection timer, the cell selection priority, and the transmission delay time.

Meanwhile, the mobile station 130 may transmit synchronization signals (e.g., PSS, SSS) and system information (S303, S305). The system information may include a move / fix indicator, a cell selection timer, a cell selection priority, a transmission delay time, and the like. When the mobile station 130 supports the cellular communication protocol, the system information may be transmitted in a broadcast manner through at least one of a system information block (SIB) and a master information block (MIB). Alternatively, when the mobile base station 130 supports the WLAN protocol, the system information may be transmitted through at least one of a probe response frame and a beacon frame.

The mobile station 130 may transmit the synchronization signal and the system information at P3 of the movement path. The seventh terminal 140-7 is located within the coverage of the mobile station 130 and can receive the synchronization signal and the system information from the mobile station 130 when the mobile station 130 is located at P3 of the movement path. For example, the seventh terminal 140-7 can receive the synchronization signal from the mobile base station 130 and can synchronize with the mobile base station 130 based on the received synchronization signal. Also, the seventh terminal 140-7 can confirm the cell ID of the mobile station 130 based on the received synchronization signal, and can register the cell ID in the candidate cell list. When the cell ID of the mobile station 130 is the mobile cell ID, the seventh MS 140-7 determines that the type of the corresponding BS is the mobile station based on the synchronization signal received from the mobile station 130 . The candidate cell list may include the cell ID of the base station (e.g., mobile station 130, etc.) discovered by the seventh terminal 140-7. The seventh UE 140-7 may perform a handover procedure from the second macro base station 120 to one BS included in the candidate cell list (or a cell selection procedure, a cell reselection procedure ). ≪ / RTI >

Meanwhile, the seventh MS 140-7 may perform a handover procedure (or a cell selection procedure, a cell selection procedure, and a cell selection procedure) when a plurality of BSs (e.g., the second macro BS 120 and the mobile BS 130) A re-selection procedure) may be performed (S304). For example, the seventh MS 140-7 may receive signal strength (e.g., received signal strength (RSSI) from the searched BSs (e.g., second macro BS 120, mobile BS 130) and the received signal strength of the second macro base station 120 and the received signal strength of the mobile station 130 can be compared. When the received signal strength of the mobile station 130 is greater than the received signal strength of the second macro base station 120 and the difference between the received signal strength of the mobile station 130 and the received signal strength of the second macro base station 120 is preset The seventh UE 140-7 may perform a handover procedure (or a cell selection procedure, a cell reselection procedure) from the second macro base station 120 to the mobile station 130.

Here, the preset value (for example, 15 dB) used when the type of the target base station of the handover is the mobile base station is a predetermined value (for example, 15 dB) used when the type of the target base station of the handover is the fixed base station For example, 10 dB). When the type of the target base station of the handover is the mobile base station, different predetermined values may be used depending on the values of the cell selection timer, the cell selection priority, and the transmission delay time of the mobile station.

If it is determined that the handover procedure (or cell selection procedure, cell reselection procedure) is performed, the seventh terminal 140-7 can receive the system information from the mobile station 130, A cell selection timer, a cell selection priority, a transmission delay time, and the like included in the cell. Although it has been described that the seventh UE 140-7 receives the system information from the mobile station 130 when it is determined that the handover procedure (or the cell selection procedure or the cell reselection procedure) is performed, 7 terminal 140-7 may determine whether to perform a handover procedure (or a cell selection procedure, a cell reselection procedure) after receiving the system information from the mobile station 130. [

The seventh terminal 140-7 may determine whether the corresponding base station is a mobile station or a fixed base station based on the movement / fix indicator included in the system information (S306). Alternatively, when the mobile cell ID is used, the seventh MS 140-7 may determine whether the corresponding BS is a mobile BS or a fixed BS based on the synchronization signal received from the MS. When it is determined that the type of the mobile station 130 is the mobile station, the seventh terminal 140-7 determines whether the mobile station 130 is connected to the mobile station 130 considering the cell selection timer, the cell selection priority, can do.

For example, the seventh MS 140-7 may compare the transmission delay time of the mobile BS 130 with a preset delay threshold. When the transmission delay time of the mobile station 130 is less than a predetermined delay threshold value (for example, when the low-delay communication service can be performed through the mobile station 130), the seventh terminal 140-7 It can be determined that the connection between the mobile stations 130 is possible. Alternatively, when the transmission delay time of the mobile station 130 is equal to or larger than a predetermined delay threshold value (for example, when the low delay communication service can not be performed through the mobile station 130), the seventh terminal 140-7 And the mobile station 130 can not be connected to each other.

If it is determined that the connection between the seventh UE 140-7 and the mobile BS 130 is possible, the seventh MS 140-7 may start the cell selection timer of the MS 130 (S307). The cell selection priority of the mobile station 130 may be set to a relatively low value during the waiting period indicated by the cell selection timer. In addition, the seventh terminal 140-7 may set an additional timer corresponding to the cell selection priority and may start "cell selection timer + addition timer ". The higher the cell selection priority, the shorter the additional timer can be set, and the lower the cell selection priority, the longer the additional timer can be set. For example, the seventh terminal 140-7 may set an additional timer based on the mapping table described in Table 2 below.

The seventh terminal 140-7 can check whether the following conditions are satisfied during the waiting period indicated by the cell selection timer (or "cell selection timer plus additional timer").

- Condition 1: The mobile station 130 is continuously searched for by the seventh terminal 140-7 during the waiting period indicated by the cell selection timer (or "cell selection timer plus additional timer").

- Condition 2: Another base station having a cell selection priority higher than the cell selection priority of the mobile station 130 during a waiting period indicated by the cell selection timer (or "cell selection timer + additional timer & (140-7).

If condition 1 is satisfied, it means that the user of the seventh terminal 140-7 has boarded the mobile means on which the mobile station 130 is located. If both condition 1 and condition 2 are satisfied, a connection procedure between the seventh terminal 140-7 and the mobile station 130 may be performed (S308). That is, the seventh terminal 140-7 may camp on the mobile base station 130. [

 After the connection procedure is completed, the seventh MS 140-7 may perform communication via the mobile BS 130 instead of the second macro BS 120. [ For example, the seventh terminal 140-7 may perform a communication service (e.g., a low delay communication service) satisfying the transmission delay time of the mobile station 130. [ Here, when a transmission delay time is generated by the mobile station 130, the communication service performed through the mobile station 130 may be different from the communication service performed through the second macro base station 120.

Also, the seventh terminal 140-7 may measure a round trip delay (RTD) in the "mobile base station 130-seventh terminal 140-7" The RTD can be measured in the communication path between the mobile base station 130 and the seventh terminal 140-7. Communication between the seventh terminal 140-7 and the mobile station 130 may be performed in consideration of the RTD.

The methods according to the present invention can be implemented in the form of program instructions that can be executed through various computer means and recorded on 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 computer readable medium may be those specially designed and constructed for the present invention or may be available to those skilled in the computer software.

Examples of computer readable media include hardware devices that are specially 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 generated 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 with at least one software module to perform the operations of the present invention, and vice versa.

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 in the appended claims. It will be possible.

Claims (20)

A method of operating a terminal in a communication network,
Receiving from the first base station system information including an indicator indicating whether the first base station is a mobile station or a fixed base station, a cell selection timer, a cell selection priority, and a transmission delay time;
Determining whether to connect to the first base station in consideration of the cell selection timer, the cell selection priority, and the transmission delay time when the indicator indicates that the first base station is the mobile station; And
And connecting to the first base station after a period indicated by the cell selection timer when connection between the terminal and the first base station is possible. The method according to claim 1,
Wherein the transmission delay time indicates a difference between a transmission time through the mobile base station connected to the core network by a wireless link and a transmission time through the fixed base station connected to the core network by a wired link. The method according to claim 1,
Wherein the cell selection priority is set differently for each of the mobile station and the fixed base station, or is differently set for each transmission delay time. The method according to claim 1,
If it is determined that the second base station having the cell selection priority higher than the cell selection priority of the first base station is not searched during the interval indicated by the cell selection timer, The method comprising: The method according to claim 1,
When the transmission delay time is less than a preset delay threshold, it is determined that connection between the terminal and the first base station is possible, and when the transmission delay time is equal to or greater than the predetermined delay threshold value, And judging that the connection is impossible. The method according to claim 1,
A method of operating a terminal,
Further comprising: after the terminal is connected to the first base station, performing a communication service satisfying the transmission delay time through the first base station. The method according to claim 1,
A method of operating a terminal,
Further comprising measuring a round trip delay (RTD) through the first base station after the terminal is connected to the first base station. The method according to claim 1,
Wherein if the communication network is a cellular network, the system information is received via at least one of a system information block (SIB) and a master information block (MIB). The method according to claim 1,
Wherein if the communication network is a wireless local area network, the system information is received via at least one of a probe response frame and a beacon frame. A method of operating a first base station in a communication network,
Generating system information including an indicator indicating that the first base station is a mobile station, a cell selection timer, a cell selection priority, and a transmission delay time; And
And transmitting the system information,
The method of claim 1, wherein the indicator, the cell selection timer, the cell selection priority, and the transmission delay time are used to determine whether the terminal has received the system information and whether the terminal is connected to the first base station. . The method of claim 10,
Wherein the transmission delay time indicates a difference between a transmission time through the mobile base station connected to the core network by a wireless link and a transmission time through a fixed base station connected to the core network by a wired link. The method of claim 10,
Wherein the cell selection priority is differently set for each of the mobile station and the fixed base station, or is differently set for each transmission delay time. The method of claim 10,
Wherein if the communication network is a cellular network, the system information is transmitted via at least one of a system information block (SIB) and a master information block (MIB). The method of claim 10,
Wherein the system information is transmitted via at least one of a probe response frame and a beacon frame when the communication network is a wireless local area network. A terminal constituting a communication network,
A processor; And
Wherein at least one instruction executed through the processor includes a memory,
Wherein the at least one instruction comprises:
From the first base station, system information including an indicator indicating whether the first base station is a mobile base station or a fixed base station, a cell selection timer, a cell selection priority, and a transmission delay time;
If the indicator indicates that the first base station is the mobile station, determining whether to connect to the first base station in consideration of the cell selection timer, the cell selection priority, and the transmission delay time; And
When the connection between the terminal and the first base station is possible, the terminal is connected to the first base station after a period indicated by the cell selection timer. 16. The method of claim 15,
Wherein the transmission delay time indicates a difference between a transmission time through the mobile base station connected to the core network by a wireless link and a transmission time through the fixed base station connected to the core network by a wired link. 16. The method of claim 15,
If it is determined that the second base station having the cell selection priority higher than the cell selection priority of the first base station is not searched during the interval indicated by the cell selection timer, Terminal. 16. The method of claim 15,
When the transmission delay time is less than a preset delay threshold, it is determined that connection between the terminal and the first base station is possible, and when the transmission delay time is equal to or greater than the predetermined delay threshold value, The terminal is judged to be impossible. 16. The method of claim 15,
Wherein the at least one instruction comprises:
And after the terminal is connected to the first base station, perform a communication service satisfying the transmission delay time through the first base station. 16. The method of claim 15,
Wherein the at least one instruction comprises:
And after the terminal is connected to the first base station, measures a round trip delay (RTD) through the first base station.

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