CN110035462B

CN110035462B - Method and apparatus for adding secondary base station in communication system

Info

Publication number: CN110035462B
Application number: CN201910255992.5A
Authority: CN
Inventors: 元盛焕; 郑相洙; 赵晟娟
Original assignee: Samsung Electronics Co Ltd
Current assignee: Samsung Electronics Co Ltd
Priority date: 2013-04-01
Filing date: 2014-04-01
Publication date: 2021-09-07
Anticipated expiration: 2034-04-01
Also published as: KR102270370B1; KR20210040009A; CN105144762B; CN110087304B; KR102235504B1; KR20140119607A; CN105144762A; CN110087304A; CN110035462A

Abstract

A primary base station and a method thereof for adding a secondary base station in a mobile communication system are provided. The method comprises the following steps: transmitting a secondary base station addition request message including a first identifier allocated by the primary base station for identifying the terminal by the primary base station, security capabilities of the terminal, and an aggregated maximum bitrate AMBR for the terminal to be used at the secondary base station to the secondary base station. And receiving a secondary base station addition confirmation message from the secondary base station if the secondary base station allows the secondary base station addition, the secondary base station addition confirmation message including a second identifier for the secondary base station to identify the terminal, which is allocated by the secondary base station. Wherein the first identifier and the second identifier are used to support dual connectivity for the terminal.

Description

Method and apparatus for adding secondary base station in communication system

The present application is a divisional application of an application entitled "method and apparatus for registering a location of a terminal in a mobile communication system" having an application date of 2014, month 4 and 1 and an application number of 201480023973.5.

Technical Field

The present disclosure relates to a location registration method and apparatus of a terminal in a mobile communication network. More particularly, the present disclosure relates to a method and apparatus for efficiently using radio resources in handover, location registration, and radio connection re-establishment procedures in view of time reduction and resource saving.

Background

Mobile communication systems have been developed to provide subscribers with voice communication services on the move. With the rapid progress of technology, mobile communication systems have evolved to support high-speed data communication services in addition to the early voice-oriented services.

Fig. 1 is a diagram illustrating a general mobile communication system according to the related art.

Referring to fig. 1, the mobile communication system includes a User Equipment (UE)100, a Radio Access Network (RAN)120, and a core network 140.

The RAN 120 may include

wireless access points

110 and 115. The

wireless access points

110 and 115 may interact with the UE 100 over a wireless interface. The other entities of the mobile communication system are mainly connected by wired links. Examples of the

wireless access points

110 and 115 include evolved node bs (enb), node bs (nb), or a Radio Network Subsystem (RNS) including the node bs, a Base Transceiver Station (BTS), or a Base Station Subsystem (BSS) including the BTS, and each wireless access point. With some exceptions, each of the

wireless access points

110 and 115 consists of at least one cell having a predetermined area, and the UE 100 is served by the respective wireless access point within the cell area. The cell represents a cell of a general cellular system, and the

wireless access points

110 and 115 are devices that manage and control the respective cells, but in the present disclosure, the terms "cell" and "wireless access point" are used interchangeably for the same meaning.

The core network 140 may include a RAN control entity 130. The RAN control entity 130 is responsible for mobility management and overall control of authentication and security. Examples of the RAN control entity may include a Mobility Management Entity (MME), a serving general packet radio service (SGSN), and so on.

In order to provide a service to the UE 100, a mobile communication system including the wireless access point 110 must maintain a connection with the UE 100 or have a context with the UE 100. The mobile communication system performs a handover procedure, a location registration procedure, or a radio connection re-establishment procedure to maintain a connection with the UE 100 or to locate the context of the UE 100 at a correct location.

The handover procedure is performed for the interaction according to the motion of the UE 100 in the connected state or other reason for changing the wireless access point. Examples of other reasons may include load balancing.

The location registration procedure includes an Attach (Attach) procedure and a Tracking Area Update (TAU) procedure. The attach procedure is performed when the UE 100 connects to the network or a separate UE 100 reconnects to the network. The TAU procedure may be performed in a wide variety of situations, typically when the UE enters a new Tracking Area (TA).

In addition to handover procedures and location registration procedures caused by UE mobility, these may occur when the wireless connection between the UE 100 and the wireless access point 110 is unstable such that it is not suitable for use for a certain duration. In this case, the radio connection re-establishment procedure may be performed between the UE 100 and the radio access point 110 before the handover procedure and the location registration procedure or without them.

The above information is presented as background information only to aid in understanding the present disclosure. No determination is made as to whether any of the above information is applicable to the prior art for this disclosure, and no assertion is made.

Disclosure of Invention

Technical problem

The following methods and apparatus are desired: which efficiently uses radio resources by improving a handover procedure, a location registration procedure, and a radio connection re-establishment procedure of a User Equipment (UE) in view of time reduction or resource saving.

Solution scheme

Aspects of the present disclosure are to address at least the above-mentioned problems and/or disadvantages and to provide at least the advantages described below. Accordingly, one aspect of the present disclosure provides methods and apparatus for: which allows for time reduction or resource saving to efficiently use radio resources by improving a handover procedure, a location registration procedure, and a radio connection re-establishment procedure of a User Equipment (UE).

In accordance with an aspect of the present disclosure, a method for adding a primary base station of a secondary base station in a communication system is provided. The method can comprise the following steps: transmitting a secondary base station addition request message including a first identifier allocated by the primary base station for identifying the terminal by the primary base station, security capabilities of the terminal, and an aggregated maximum bit rate AMBR for the terminal to be used at the secondary base station, to the secondary base station; and receiving a secondary base station addition confirmation message from the secondary base station if the secondary base station allows the secondary base station addition, the secondary base station addition confirmation message including a second identifier for the secondary base station to identify the terminal, which is allocated by the secondary base station. Wherein the first identifier and the second identifier are used to support dual connectivity for the terminal.

In accordance with another aspect of the present disclosure, a method of a secondary base station in a communication system is provided. The method can comprise the following steps: receiving a secondary base station addition request message from the primary base station, the secondary base station addition request message including a first identifier allocated by the primary base station for identifying the terminal by the primary base station, security capabilities of the terminal, and an aggregated maximum bit rate AMBR for the terminal to be used at the secondary base station; and if the secondary base station allows the secondary base station to add, transmitting a secondary base station addition confirmation message to the primary base station, the secondary base station addition confirmation message including a second identifier for the secondary base station to identify the terminal, which is allocated by the secondary base station. Wherein the first identifier and the second identifier are used to support dual connectivity for the terminal.

In accordance with another aspect of the present disclosure, a primary base station for adding a secondary base station in a communication system is provided. The primary base station may include a transceiver and a controller. The transceiver is configured to transmit and receive signals. The controller is configured to: transmitting a secondary base station addition request message including a first identifier allocated by the primary base station for identifying the terminal by the primary base station, security capabilities of the terminal, and an aggregated maximum bit rate AMBR for the terminal to be used at the secondary base station, to the secondary base station; and receiving a secondary base station addition confirmation message from the secondary base station if the secondary base station allows the secondary base station addition, the secondary base station addition confirmation message including a second identifier allocated by the secondary base station for the secondary base station to identify the terminal, wherein the first identifier and the second identifier are used to support dual connectivity for the terminal.

In accordance with another aspect of the present disclosure, a secondary base station in a communication system is provided. The secondary base station includes a transceiver and a controller. The transceiver is configured to transmit and receive signals. The controller is configured to: receiving a secondary base station addition request message from the primary base station, the secondary base station addition request message including a first identifier allocated by the primary base station for identifying the terminal by the primary base station, security capabilities of the terminal, and an aggregated maximum bit rate AMBR for the terminal to be used at the secondary base station; and if the secondary base station allows the secondary base station to add, transmitting a secondary base station addition confirmation message to the primary base station, the secondary base station addition confirmation message including a second identifier allocated by the secondary base station for the secondary base station to identify the terminal, wherein the first identifier and the second identifier are used to support dual connectivity for the terminal.

In accordance with another aspect of the present disclosure, there is provided a location registration method of a terminal in a mobile communication system. The location registration method includes: the method includes transmitting a location registration request message to a network, waiting until a wireless connection with the network is completely released when a reject message is received from the network in response to the location registration request message, and transmitting a new location registration request message to the network when the wireless connection is released.

In accordance with another aspect of the present disclosure, there is provided a location registration method of a terminal in a mobile communication system. The location registration method includes: a location registration request message is sent to the network, and when a reject message is received from the network in response to the location registration request, a new location registration request message is immediately sent to the network.

In accordance with another aspect of the present disclosure, there is provided a location registration control method of a base station in a mobile communication system. The position registration control method includes: the method includes receiving a connection release command message from a core network in response to a location request of the terminal, and transmitting the connection release message to the terminal when the connection release command message is received.

In accordance with another aspect of the present disclosure, there is provided a location registration control method of a base station in a mobile communication system. The position registration control method includes: receiving a connection release command message from a core network in response to a location request of a terminal, and waiting until a new location registration request message for the network is received from the terminal.

In accordance with another aspect of the present disclosure, there is provided a terminal for performing location registration in a mobile communication system. The terminal includes: a transceiver configured to transmit and receive signals and data to and from a network; and a controller configured to transmit a location registration request message to the network, wait until a wireless connection with the network is completely released when a reject message is received from the network in response to the location registration request message, and transmit a new location registration request message to the network when the wireless connection is released.

In accordance with another aspect of the present disclosure, there is provided a terminal for performing location registration in a mobile communication system. The terminal includes: a transceiver configured to transmit and receive signals and data to and from a network; and a controller configured to transmit a location registration request message to the network, and immediately transmit a new location registration request message to the network when a reject message is received from the network in response to the location registration request message.

In accordance with another aspect of the present disclosure, there is provided a base station controlling location registration of a terminal in a mobile communication system. The base station includes: a transceiver configured to transmit and receive signals and data to and from a terminal; and a controller configured to receive a connection release command message from the core network in response to a location request of the terminal, and to transmit the connection release message to the terminal when the connection release command message is received.

In accordance with still another aspect of the present disclosure, there is provided a base station controlling location registration of a terminal in a mobile communication system. The base station includes: a transceiver configured to transmit and receive signals and data to and from a terminal; and a controller configured to receive a connection release command message from the core network in response to a location request of the terminal, and wait until a new location registration request message for the network is received from the terminal.

Other aspects, advantages, and salient features of the disclosure will become apparent to those skilled in the art from the following detailed description, which, taken in conjunction with the annexed drawings, discloses various embodiments of the disclosure.

Drawings

The above and other aspects, features and advantages of particular embodiments of the present disclosure will become more apparent from the following description when taken in conjunction with the accompanying drawings, in which:

fig. 1 is a diagram illustrating a general mobile communication system according to a related art;

fig. 2 is a diagram illustrating a situation causing a first problem according to an embodiment of the present disclosure;

fig. 3 is a signal flow diagram illustrating a signal flow between a User Equipment (UE) and a network according to an embodiment of the present disclosure;

fig. 4 is a signal flow diagram illustrating the signal flow between the RAN control and the wireless access point according to an embodiment of the present disclosure;

fig. 5 is a signal flow diagram illustrating a process of relaying a location registration message of a UE reusing radio resources at a radio access point according to an embodiment of the present disclosure;

fig. 6 is a signal flow diagram illustrating a signal flow for identifying a UE in handover between a primary wireless access point and a secondary wireless access point interacting secondary (secondary) with a target wireless access point, in accordance with an embodiment of the present disclosure;

fig. 7 is a signal flow diagram illustrating a radio connection establishment procedure for reusing a radio connection by utilizing a radio access point with which a UE has secondarily interacted according to an embodiment of the present disclosure.

Fig. 8 is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure; and

fig. 9 is a block diagram illustrating a configuration of a wireless access point (e.g., an evolved node b (enb)) according to an embodiment of the present disclosure.

Throughout the drawings, like reference numerals will be understood to refer to like parts, components and structures.

Detailed Description

This application claims the rights of korean patent application No. 10-2013-.

The following description with reference to the accompanying drawings is provided to assist in a comprehensive understanding of various embodiments of the disclosure as defined by the claims and their equivalents. The following description includes various specific details to aid understanding, but these specific details are to be considered exemplary only. Accordingly, those of ordinary skill in the art will recognize that various changes and modifications of the various embodiments described herein can be made without departing from the scope and spirit of the present disclosure. Moreover, descriptions of well-known functions and constructions may be omitted for clarity and conciseness.

The terms and words used in the following description and claims are not limited to bibliographic meanings, but are used by the inventors solely for the purpose of providing a clear and consistent understanding of the disclosure. Accordingly, it should be apparent to those skilled in the art that the following descriptions of the various embodiments of the present disclosure are provided for illustration only and not for the purpose of limiting the disclosure as defined by the appended claims and their equivalents.

It is to be understood that the singular forms "a", "an" and "the" include plural referents unless the context clearly dictates otherwise. Thus, for example, reference to "a component surface" includes reference to one or more of such surfaces.

Although various embodiments of the present disclosure are directed to a Radio Access Network (RAN) and an Evolved Packet Core (EPC) as Core networks that comply with the 3 rd generation partnership project (3GPP) standard Long Term Evolution (LTE), the subject matter of the present disclosure may be applied to other types of communication systems having similar technical backgrounds with a small amount of operation without departing from the scope of the present disclosure, and this will be understood by those skilled in the art of the present disclosure.

Unlike conventional systems in which a User Equipment (UE)100 interacts with a wireless access point 110, recent systems allow the UE 100 to interact with one or more

wireless access points

110 and 115. As described above, fig. 1 shows two

wireless access points

110 and 115 connected to a UE 100. However, the present disclosure is not limited to the embodiment of fig. 1, and it is apparent that the UE 100 does not always interact with the two

wireless access points

110 and 115.

Throughout the specification, unless otherwise stated, if one access point 110 is referred to, this indicates a general wireless access point; and if the two

wireless access points

110 and 115 are mentioned together, this indicates that the first wireless access point is the wireless access point 110 with which the UE 100 primarily interacts, and the second wireless access point is the wireless access point 115 with which the UE 100 secondarily interacts. If the number of wireless access points to which the UE 100 is connected is 3 or more, the number of wireless access points secondarily interacting with the UE 100 may be one or more.

In the above network structure, the following problems may occur. One problem is that a UE 100 failing to register a location for some reason takes a long time for re-attempting location registration to a corresponding wireless access point 110, and another problem is that when the connection state of a wireless access point 110 with which the UE primarily interacts deteriorates, the connection state of a wireless access point 115 with which the UE secondarily interacts is not considered, resulting in waste of resources. Problematic situations are described in more detail.

Fig. 2 is a diagram illustrating a situation causing a first problem according to an embodiment of the present disclosure.

Referring to fig. 2, the UE 100 may be registered with and/or receive service from a mobile communication system operating with different Radio Access Technologies (RATs) and/or different RAN control entity groups having different RAN control entity group identifiers. The UE may be in an idle state.

If the UE 100 has moved from another RAT or another group of RAN control entities, e.g., from the area 200 to the area 300, as indicated by reference numeral 210, the UE 100 sends a Tracking Area Update (TAU) request message to the RAN control entity 130. Alternatively, if any data to be transmitted to and/or received from the network is present at the UE 100 as represented by reference numeral 215, the UE sends a service request message to the RAN control entity 130. Messages sent from UE 100 to RAN control entity 130 are relayed by radio access point 110.

If a problem occurs in receiving the TAU request message or the service request message from the UE 100, the RAN control entity 130 may transmit a message rejecting the request message of the UE 100, i.e., a TAU reject message or a service reject message, to the UE 100. RAN control entity 130 may include information in the reject message describing and/or implying the cause of the problem. The reject message is sent from RAN control entity 130 to UE 100 via radio access point 110.

If a reject message is received from RAN control entity 130 as represented by reference numeral 240, UE 100 may send a new attach request message to RAN control entity 130 as represented by reference numeral 280 that includes the cause carried in the reject message. Examples of reasons may include a case where RAN control entity 130 fails to acquire an identifier of UE 100, a case where UE 100 is implicitly separated, and a case where bearer information is not activated at all. These three causes are matched with cause values 9, 10 and 40, respectively, in an Evolved Packet System (EPS).

After sending the reject message to the UE 100, the RAN control entity 130 may instruct the wireless access point 110 to release the context for the UE 100 as denoted by reference numeral 250. This command may be transmitted using a UE context release command message.

If a release order is received from RAN control entity 130, wireless access point 110 may send a message to UE 100 requesting connection release. An example of the connection release message transmitted from the wireless access point 110 to the UE 100 includes an RRCConnectionRelease message.

If the release message transmitted from the wireless access point 110 to the UE 100 as denoted by reference numeral 260 arrives and thus the radio connection to the network is completely released earlier than the time when the UE 100 transmits a new attach request message to the RAN control entity 130 as denoted by reference numeral 280, the UE 100 can perform the attach procedure without problems.

Otherwise, a problem may arise if the time at which the release message sent from the radio access point 110 to the UE 100 arrives as denoted by reference numeral 260 and thus the radio connection to the network is completely released is later than the time at which the UE 100 sends a new attach request message to the RAN control entity 130 as denoted by reference numeral 280. That is, this case means that the UE 100 transmits an attach request message to the RAN control entity 130 and then the radio connection is released. Thus, the UE 100 sees this as a problematic situation in the attach procedure and waits a relatively long time (e.g., 10 seconds) to attempt location registration again. While waiting for a long time, the UE 100 cannot receive the service and thus the user suffers inconvenience.

The description consists of an embodiment of the present disclosure for solving the problem described with reference to fig. 2. However, the problem to be solved is not limited to the case as shown in fig. 2, but includes all cases that significantly increase the time required for a UE that fails to perform location registration for some reason to perform location registration again with a corresponding wireless access point.

To address the above issues, the present disclosure is described in connection with two different embodiments. It is however obvious to a person skilled in the art that all available modifications can be made to the various embodiments which will be described below to implement the technical idea of the present disclosure.

Referring to fig. 2, an embodiment of the present disclosure has the following properties: which causes the release message sent from the radio access point to the UE 100 as represented by reference numeral 260 to arrive at a time prior to the time at which the UE 100 sends the new attach request message to the RAN control entity 130 as represented by reference data 280.

Another embodiment of the present disclosure has the following properties: which prevents the connection between the UE 100 and the wireless access point 110 from being released, i.e. cancelling the operation as indicated by reference numeral 260 in fig. 2. According to the present embodiment, the release message is not transmitted from the radio access point 110 to the UE 100.

The difference between the two different embodiments above is whether the wireless connection is used again. That is, the former embodiment is characterized in that the connection between the UE 100 and the wireless access point 110 is released at the UE 100 for new location registration without any penalty. The latter embodiment is characterized by reusing the previously established radio connection without releasing the connection between the UE 100 and the radio access point 110 in order to request a new location registration.

All of these two different embodiments are able to avoid that the time at which the radio connection is released due to the arrival of the release message sent from the radio access point 110 to the UE 100 is after the time at which the UE 100 sends a new location registration request to the RAN control entity 130, thereby avoiding that the UE waits a long time to request location registration again, resulting in a reduction of the delay time.

Fig. 3 is a signal flow diagram illustrating a signal flow between a UE and a network according to an embodiment of the present disclosure, and in more detail, shows an operation in which a RAN control entity transmits an indicator indicating necessity of new location registration of a terminal and one of a timer transmitted to the UE by the RAN control entity or the radio access point to a radio access point.

Referring to fig. 3, the UE 100 and the wireless access point 110 may be aware of a situation where a new location registration procedure is required. The UE 100 or the wireless access point 110 may transmit a message triggering a new location registration procedure or a radio connection release procedure based on the timer.

The RAN control entity 130 may determine the necessity of a new location registration of the UE 100 in operation 310 in certain problematic situations. As described above, the problematic case may be a case corresponding to at least one of the cause values 9, 10, and 40 used in the EPS. The determination made by the RAN control entity 130 at operation 310 may be in the nature of a location registration or service request by the UE 100.

RAN control entity 130 may send at least one of a timer and an indicator informing of the necessity of a new location registration of UE 100 to radio access point 110. The information sent from RAN control entity 130 to radio access point 110 may be carried in a downlink NAS transport message. The downlink NAS transport message is used to transport a Non-Access Stratum (NAS) message between the UE 100 and the RAN control entity 130. Examples of NAS messages carried in downlink NAS transport messages include TAU reject and service reject. The information sent from RAN control entity 130 to radio access point 110 may be sent using a UE context release order message for ordering UE 100 to release the connection.

The indicator informing the UE 100 of the necessity of new location registration may be expressed in various ways. For example, the indicator may be expressed using simple binary information or a reason or cause value for a new location registration necessity situation of the UE.

The wireless access point 110 may transmit a timer to the UE at operation 330. The timer may be included in the dlinformation transfer message or in a NAS message carried in the dlinformation transfer message.

The timer transmitted from the RAN control entity 130 to the radio access point 110 and the timer transmitted from the radio access point 110 to the UE 100 in operation 320 may be set to the same value or different values.

Hereinafter, the description consists of operations of RAN control entity 130 and radio access point 110 in case radio access point 110 receives an indicator informing of the necessity of new location registration of UE 100 from RAN control entity 130 and a timer or fails to receive both the indicator and the timer in accordance with an embodiment of the present disclosure in the situation shown in fig. 3.

In case the radio access point 110 receives neither the indicator nor the timer from the RAN control entity 130, it is necessary for the UE 100 to release the radio connection as soon as possible before requesting a new location registration in the network.

Thus, detecting that a new location registration of the UE 100 is required, the RAN control entity 130 sends a UE context release order message to the radio access point 110 as immediately as possible. For example, the UE context release command message may be transmitted to the wireless access point 110 immediately after transmitting a NAS message notifying location registration rejection to the UE 100. Further, upon receiving the UE release order message from RAN control entity 130, radio access point 110 may release the radio connection of UE 100. For example, upon receiving the UE context release order message from the RAN control entity 130, the wireless access point 110 may send a UE context release RRCConnectionRelease message to the UE 100. Further, the UE 100 may release the radio connection upon receiving the connection release message from the radio access point 110.

In case the radio access point 110 receives the indicator from the RAN control entity 130 without receiving the timer, the radio access point 110 knows that the UE 100 is requesting a new location registration. Thus, the wireless access point 110 can release the wireless communication of the UE 100 immediately after recognizing a situation requiring a new location registration using the indicator, regardless of the UE context release command message transmission of the control entity 130.

For example, if the indicator is received through the UE context release order message, the wireless access point 110 immediately transmits an RRCConnectionRelease message to the UE 100, and if the indicator is received through another type of message, the wireless access point 110 may immediately transmit an RRCConnectionRelease message to the UE 100 even before the UE context release order message is received.

If a timer is received from RAN control entity 130, wireless access point 110 is able to release the wireless communication of UE 100 for a time indicated or indicated by the timer starting at the appropriate time. The timer is responsible for the agreed function. For example, UE 100 does not request location registration from RAN control entity 130 for the time indicated or indicated by the timer received from wireless access point 110. Examples of times suitable for starting the timer include the time at which the wireless access point 110 received the timer.

Next, the description consists of a procedure in which the UE 100 reuses a radio connection to request a new location registration in accordance with another embodiment of the present disclosure in the situation as depicted in fig. 3.

If both the new location registration necessity indicator and the timer for the UE 100 are not received in operation 320, it is necessary for the wireless access point 110 to maintain the wireless connection for a predetermined duration in order for the UE 100 to reuse the already existing wireless connection to perform the new location registration. The predetermined duration may be determined by a unique timer of the wireless access point 110.

Thus, if it is identified in operation 310 that a new location registration of the UE 100 is required, the RAN control entity 130 may not send a UE context release order message to the wireless access point 110 in operation 320. Although receiving the UE context release order message from the RAN control entity 130, the radio access point 110 may wait for a predetermined time without releasing the radio connection of the UE 100.

If the UE requests a new location registration from the radio access point 110 while waiting for a predetermined time, the radio access point 110 may disregard the UE context release order message received from the RAN control entity 130 so as not to release the radio connection of the UE 100.

In the case where only the indicator is received from the RAN control entity 130 without receiving the timer, the wireless access point 110 determines that the UE 100 is requesting a new location registration. Thus, if it is determined that a new location registration of the UE is required based on the indicator independently of the UE context release order message transmitted by RAN control entity 130, wireless access point 110 waits to receive a new location registration request from UE 100 without releasing its radio connection. The latency of the wireless access point 110 may be maintained before the unique timer of the wireless access point 110 times out.

Upon receiving the timer from RAN control entity 130, radio access point 110 maintains the radio connection of UE 100 for a duration indicated or indicated by the timer from a particular point in time. The timer can be considered a contracted function. For example, the UE 100 transmits a new location registration request within the time indicated or indicated by the received timer. Examples of times suitable for starting the timer include the time at which the wireless access point 110 received the timer.

Hereinafter, the description is specifically made of the operation of the UE 100 according to various embodiments of the present disclosure in the context of fig. 3.

According to an embodiment of the present disclosure, if a timer (related to location registration) is not received from the network at operation 330 of fig. 3, the UE 100 may wait until a radio connection and/or NAS (non-access stratum) signaling is released by the radio access point 110, and if the radio connection is released, the UE 100 requests a new location registration.

The UE 100 may also request a new location registration using an alternative to the above-described method. That is, if a predetermined duration of time to wait for the release of the radio connection and/or NAS (non-access stratum) signaling elapses, the UE 100 releases the radio connection and/or NAS (non-access stratum) signaling to the radio access point 110 and establishes a new request for location registration. The predetermined duration is clearly indicative of the specified duration. For example, the predetermined duration may be a value of a timer (i.e., 10 seconds) of a T3440 timer of the UE 100.

If the timer is received in operation 330, the UE 100 may request a new location registration at least after the time indicated or indicated by the timer elapses. If the radio connection is released before the timer expires, the UE stops the timer and requests a new location registration.

The terminal 100 can know the necessity of new location registration based on a message received from the network, for example, a location registration reject message, and thus it is efficient to release the wireless connection as soon as possible in view of time reduction. Thus, the UE 100 can be detached from the connected state without delay when receiving a message instructing the release of the wireless connection from the wireless access point 110. The information letting the UE know of the situation where a new location registration procedure is required may be information received on the NAS layer. In order to get the UE 100 out of the connected state without delay, the NAS layer transmits the information to the RRC layer.

The present UE 100 is designed to delay the radio connection release procedure by a duration of 60ms when a radio connection release message is received from the radio access point 110 in a specific situation. Thus, in embodiments of the present disclosure, if the UE 100 is "out of the connected state without delay," this means that the UE is out of the connected state "within 60ms from the receipt of the message" or "without waiting for 60 ms.

According to another embodiment of the present disclosure, if the timer is not received at operation 330 of fig. 3, the UE 100 may send a new location registration request to the RAN control entity 130 immediately after operation 330. If the timer is received in operation 330, the UE 100 may send a new location registration request to the RAN control entity 130 for a duration indicated or indicated by the timer.

Whether the UE re-uses the radio connection for a new location registration may be determined in another embodiment depending on the situation.

According to an embodiment of the present disclosure, the RAN control entity 130 may start a timer when a new location registration of the UE 100 is required for operation 310 of fig. 3. The timer may be the same or different from the timer sent from RAN control entity 130 to radio access point 110. The timer of RAN control entity 130 may start after or at the moment at least one of the indicator and the timer is sent to the radio access point 110 by the location registration message in operation 320.

If the UE sends a new location registration request to RAN control entity 130 before the timer expires, RAN control entity 130 may perform location registration of UE 100 without releasing the radio connection by sending a UE context release command message to radio access point 110. That is, the location registration is performed with reuse of the wireless connection. If UE 100 attempts location registration before the timer expires in this manner, RAN control entity 130 stops or terminates the timer upon receiving the location registration request message.

Otherwise, if the UE 100 does not send a new location registration request before the timer expires, the RAN control entity 130 triggers a radio connection release. The radio connection release may be triggered by sending a UE context release order message to the radio access point 110.

Fig. 4 is a signal flow diagram illustrating a signal flow between a RAN control entity and a wireless access point according to an embodiment of the present disclosure.

As described above, according to another embodiment of the present disclosure, even when RAN control entity 130 orders the context release by transmitting a UE context release order message to wireless access point 110, wireless access point 110 may not release the UE context or the radio connection. Thus, radio access point 110 may inform RAN control entity 130 of the UE context or that the radio connection is not released. If the UE 100 has requested a new location registration by reusing an already established radio connection, the following may be necessary: the wireless access point 110 maintains the wireless connection for a predetermined duration even when a context release or wireless connection release message is received from the RAN control entity 130 as described above.

Referring to fig. 4, the RAN control entity 130 may transmit a message commanding a context release of the UE 100 to the radio access point 110 in operation 410. Examples of the message transmitted in operation 410 may include a UE context release order message. After receiving the message from RAN control entity 130, wireless access point 110 may not perform a context release or a radio connection release regardless of the command from the RAN control entity.

In operation 420, the radio access point 110 may inform the RAN control entity 130 that the UE context or the radio connection has not been released by sending an announcement message. Examples of the message transmitted at operation 420 may include a UE context release complete message and an error indication message. The message sent from radio access point 110 to RAN control entity 130 may include an Information Element (IE) informing the UE that the context or radio connection has not been released. Examples of IEs that may be carried in this message include a cause value and an indicator.

The message sent from wireless access point 110 to RAN control entity 130 may be a new type of message. In case the IE informing not to run UE related release is carried in a new type of message, the new message may be referred to as UE context release failure message in embodiments.

In the conventional method, if RAN control entity 130 instructs wireless access point 110 to release the context, wireless access point 110 must execute the instruction. However, in the above-described embodiments of the present disclosure, the wireless access point 110 may not release the context or the wireless connection in a particular situation.

In case of applying the procedure of fig. 4 to another embodiment, RAN control entity 130 sends a context release command in operation 410 when a new location registration request is not received from wireless access point 110 before the timer of wireless access point 110 expires. Although the context release command is sent to the wireless access point 110 due to expiration of the timer of the RAN control entity 130, the wireless access point 110 may send a message notifying that the message context release is not run before the expiration of its own timer at operation 420.

Fig. 5 is a signal flow diagram illustrating a procedure of relaying a location registration message of a UE reusing a radio resource at a radio access point according to an embodiment of the present disclosure.

Referring to fig. 5, the wireless access point 110 can successfully relay the location registration request message to the RAN control entity 130 even when the UE 100 transmits the message by reusing radio resources.

Referring to fig. 5, the UE 100 transmits a location registration request message to the wireless access point 110 in operation 510. The message sent by the UE may be a NAS message to the RAN control entity 130 and may be carried in a ULInformationTransfer message. In the case where the UE 100 requests a new location registration by reusing a wireless connection according to an embodiment of the present disclosure, the UE may include specific information in the location registration request message. The specific information included in the message may have the following properties: it informs the UE to re-request location registration by reusing the radio connection.

The wireless access point 110 may transmit a location registration request message for the UE 100 to the RAN control entity 130 in operation 520. One of the initial UE message and the uplink NAS transport message may be used to send a message for the UE 100.

The conventional location registration request message is mainly carried by the initial UE message. The initial UE message includes IEs defined for the transmission of location registration messages that are different from the uplink and downlink NAS transport messages carrying the general NAS message. The initial UE message is restricted so as to carry only the NAS message that was sent first from the establishment of the radio connection.

However, it may be necessary to transmit the location registration request message in a specific case in addition to the NAS message transmitted first from the radio connection setup. Thus, the procedure needs to be modified so that the initial UE message can be sent in situations other than the case where the NAS message is sent first from the establishment of the radio connection of the UE 100. Examples of such a case may include a case where the UE transmits a ULInformationTransfer message including specific information and a case where the RAN control entity 130 notifies the UE to re-request location registration.

In the case where the message relayed by the wireless access point 110 is an uplink NAS transport message, the wireless access point 110 may include at least one of the IEs included in the initial UE message, such as RRC establishment cause, S-TMSI, CSG Id, GUMMEI, cell access mode, breakout node indicator, GUMMEI type, and tunnel information for BBF in the uplink NAS transport message.

In case of applying the procedure of fig. 5 to the embodiment, if the location registration request message of the UE 100 is transmitted before the timer of the RAN control entity 130 expires, the RAN control entity 130 may perform location registration of the UE by reusing the radio connection.

The description is made of the second problem to be solved by the present disclosure hereinafter.

The second problem has the background that the UE 100 is interacting with two or more

wireless access points

110 and 115 as shown in fig. 1. The UE 100 mainly interacts with the wireless access point 110, and may change the currently interacting wireless access point when the wireless connection state with the wireless access point 110 becomes lower than a predetermined level. The new wireless access point, i.e., the target wireless access point, with which the UE 100 primarily interacts may be the wireless access point 115 that has previously interacted with the UE 100 secondarily.

In conventional handover procedures, no mechanism is defined for reuse of all or a portion of the wireless connection between the UE 100 and the wireless access point 115 that secondarily interoperates with the UE 100, and thus there is no difference between handover to the wireless access point 115 that secondarily interacted with the UE 100 before and handover to a wireless access point that does not interact with the UE.

If the radio access point 11, which mainly interacts with the UE 100, fails to start handover of the UE in time, Radio Link Failure (RLF) or handover failure (HOF) may occur between the UE 100 and the radio access point 110, which mainly interacts with the UE 100. A UE 100 experiencing RLF or HOF with a mainly interacting radio access point 110 may attempt radio connection re-establishment. The target of the UE 100 in attempting the radio connection re-establishment may be a radio access point 115 with which the UE 100 secondarily interacts.

Even when the UE 100 experiences RLF or HOF with the primary interworking wireless access point 110, if the wireless connection state between the secondary interworking wireless access point 115 and the UE 100 is good, the wireless connection with the secondary interworking wireless access point 115 may be maintained. However, in the conventional radio connection re-establishment procedure, the radio connection state between the UE and the radio access point 115 for the secondary interaction is not considered. Further, according to the conventional radio connection re-establishment procedure, the radio connection re-establishment may be performed after the connection between the radio access point 115 of the secondary interaction and the UE 100 has been released.

Although there is additional space for saving resources by reusing radio resources in the case where any wireless access point 115 interacting secondarily with the UE 100 exists in the handover and radio connection re-establishment procedures of the UE as described above, any mechanism for reflecting this is not defined in the conventional method.

With respect to handover of the UE 100, the UE 100 or the wireless access point 115 verifies that the target wireless access point 115 is a wireless access point 115 that has secondarily interacted before handover, and then completes the wireless connection reconfiguration procedure by reusing the already established wireless connection.

Regarding the radio connection re-establishment of the UE 100, if the radio connection re-establishment target is the radio access point 115 that has interacted secondarily, the UE 100 or the radio access point 115 may complete the radio connection re-establishment procedure by reusing the already existing radio connection.

In the above two methods, the wireless connection with the wireless access point 115 secondarily interacting with the UE is reused for a specific procedure, thereby saving power consumption.

Hereinafter, the description is made of handover and radio connection re-establishment procedures of the UE 100 according to an embodiment of the present disclosure.

During handover of the UE 100, the UE 100 or the wireless access point 115 verifies that the target wireless access point 115 is a wireless access point that has secondarily interacted with the UE 100 before handover, and completes a wireless connection reconfiguration procedure by reusing an already existing wireless connection.

The UE 100 may even utilize conventional mechanisms to verify that the target wireless access point 115 is the wireless access point that has secondarily interacted with the UE 100 prior to the handover. However, the target wireless access point 115 may not be able to recognize that the UE 100 involved in the handover is a UE 100 with which it has secondarily interacted.

Fig. 6 is a signal flow diagram illustrating a signal flow for identifying a UE in handover between primary and secondary wireless access points interacting secondarily with a target wireless access point, according to an embodiment of the present disclosure.

Referring to fig. 6, the wireless access point 110 primarily serving the UE 100, i.e., the primary wireless access point 110, may transmit a message requesting to secondarily serve the UE to the wireless access point 115 in operation 610. The transmitted request message may be any one of an SCell addition request, a SENB addition request, or an SCG addition request message. The request message may include at least one of an identifier for identifying the UE 100 at the wireless access point and an identifier for identifying the UE 100 at the wireless access point 115. The included identifier may be any one of a C-RNTI and an eNB UE X2AP ID.

The message sent at operation 610 may include other information besides the identifier to successfully request the wireless access point 115 to secondarily serve the UE 100. For example, the message may include at least one of a sub-identifier of the wireless access point 115, bearer information for a service of the wireless access point 115, access restriction information of the UE 100, an identifier of a RAN control entity 130 controlling the UE 100, an identifier for identifying the UE at the RAN control entity 130, security capabilities of the UE 100, AS security information, an Aggregate Maximum Bit Rate (AMBR), and a CSG membership status.

The sub-identifier of the wireless access point 115 may be expressed in the form of an E-UTRAN cell global identifier, ECGI). If the wireless access point 115 is an eNB, it may be necessary to send an ECGI for cell-specific identification of the eNB. The bearer information that the wireless access point 115 wants to serve may include at least one of a bearer identifier, a downlink transmission proposal, uplink GTP tunnel endpoint information, and a bearer QoS parameter. It may be necessary for the wireless access point 115 to reserve the required resources if the entity indicated by the sub-identifier of the wireless access point 115 admits at least one of the bearers indicated by the service bearer identifier.

The resource restriction information of the UE 100 may include information on resources available to the UE 100. The resource usage Restriction information may be a Handover Restriction List (HRL). Since HRL is mobility information, other new information about resource usage can be introduced.

If an identifier of the RAN control entity 130 controlling the UE 100 is received, the radio access point 115 is able to identify the RAN control entity 130 using the identifier of the RAN control entity 130 controlling the UE 100 when interaction with the RAN control entity 130 is necessary. Further, when interacting with RAN control entity 130, UE 100 may be identified with an identifier for identification of UE 100.

The wireless access point 115 prepares an AS security configuration with reference to at least one of security capabilities and AS security information. More specifically, the wireless access point 115 may perform AS security configuration including AS security key creation according to security capabilities and/or AS security information. At least one of the security capabilities and the AS security information may be sent only when the request message contains a bearer directly (not through the wireless access point 110) between the wireless access point 115 and the core network 140.

The wireless access point 115 can schedule such that the sum of the bit rates for a particular bearer serving the UE 100 does not exceed the AMBR of the UE 100. The specific bearer may represent all bearers for the radio access bearer 115 serving the UE or all data bearers for the UE 100 serving the UE 100. Further, the specific bearer may indicate a non-guaranteed bit rate bearer configured to be communicated directly (not through the wireless access point 110) to the core network 140.

The CSG membership status represents a result of membership authentication or access control that the UE 100 or the UE 100 and the wireless access point 110 have performed on the wireless access point 115. If it is determined that the CSG membership status is invalid, the wireless access point 115 may transmit the correct CSG membership status or the wireless access point 115 may reject the request at operation 620.

The wireless access point 115, i.e., the secondary wireless access point 115, may send a message to the primary wireless access point 110 to accept secondary services to the wireless access point 115 of the UE 100 at operation 620. The accept message may be any one of SCell addition acknowledgement, SENB addition acknowledgement, or SCG addition acknowledgement. The acceptance message may include an identifier used by the wireless access point 115 to identify the UE 100. The identifier may be one of a C-RNTI and an eNB UE X2 AP. The acceptance message may include at least one of information on a bearer that the wireless access point 115 has accepted among the bearers requested by the wireless access point 110 for service and information on a bearer that the wireless access point 115 has rejected.

The primary wireless access point 110 may send a handover request message for the UE 100 to the secondary wireless access point 115 at operation 630. The HANDOVER REQUEST message may be a HANDOVER REQUEST message. The HANDOVER re qeust message may include the identifier received from the secondary wireless access point 115 at operation 620.

The secondary wireless access point 110 may send a handover accept message to the primary wireless access point 110 at operation 640. The handover accept message may be a handover request confirm message. The handover accept message may further include an rrcconnectionreconfiguration message, and the rrcconnectionreconfiguration message may include information on omitting at least one of a random access procedure, uplink synchronization, and uplink allocation of the UE 100. This information may be expressed in the form of a bitmap.

The rrcconnectionreconfiguration message received from the secondary wireless access point 115 may be transmitted to the UE 100, and thus, the UE 100 may skip the random access procedure in the handover procedure to the secondary wireless access point 115.

Referring to fig. 7, the UE 100 detects an RLF or an HOF of the primary radio access point 110 in operation 710. The UE is able to verify that the wireless access point 115 to which the wireless connection re-establishment request message is sent is the wireless access point 115 with which the UE 100 has secondarily interacted, i.e. the secondary wireless access point 115. In this case, in the initial stage of the radio connection re-establishment procedure, the UE 100 can release the connection with other secondarily interacting radio access points, except for the secondary radio access point 115.

The UE may transmit a wireless connection reestablishment request message to the secondary wireless access point 115 at operation 720. The wireless connection reestablishment message may be an rrcconnectionrequestrequest message. The UE 100 may skip the random access procedure before transmitting the radio connection reestablishment request message.

The wireless connection reestablishment request message may include at least one of an identifier used by the secondary wireless access point 115 to identify the UE 100, an identifier of the secondary wireless access point 115, and a shortMAC-I for the secondary wireless access point.

The identifier used by the secondary radio access point 115 to identify the UE 100 may be a C-RNTI. The identifier of the secondary wireless access point 115 may be a Physical Cell Identity (PCI) or ECGI. The identifier used by the secondary wireless access point 115 to identify the UE and the identifier of the secondary wireless access point 115 may be paired in the request message.

The secondary wireless access point 115 may retrieve the UE context using the UE and the identifier of the secondary wireless access point included in the request message. Further, the secondary wireless access point 115 may identify and interrogate the UE 100 using shortMAC-1 for the secondary wireless access point.

The secondary wireless access point 115 retrieves UE information in cooperation with the primary wireless access point 110 at operation 730. The secondary wireless access point 115 may send a UE information request message to the primary wireless access point 110. The primary wireless access point 110 may provide the UE information if the request message is received. Examples of UE information provided by the primary wireless access point 110 may include UE radio access capability information, AS configuration, AS context, and Radio Resource Management (RRM) configuration. The wireless access point 115 may store the received UE information and use the received UE information to communicate with the UE. In addition, the wireless access point 115 may also transmit the stored UE information to other entities at the same time as the handover procedure caused by the mobility of the UE 100.

In the above description of the embodiments, the wireless access point 110 and the wireless access point 115 are referred to as a primary wireless access point and a secondary wireless access point, respectively. However, the wireless access point 110 may refer to a wireless access point that is in service to the UE before the connection failure, and the wireless access point 115 may refer to a wireless access point to which the UE requests a wireless connection re-establishment after the connection failure in general.

Fig. 8 is a block diagram illustrating a configuration of a UE according to an embodiment of the present disclosure.

Referring to fig. 8, a UE according to an embodiment of the present disclosure includes a transceiver 810, a multiplexer/demultiplexer 820, a higher layer device 830, a control message processor 840, and a controller 850.

The transceiver 810 receives data and control signals from a network, i.e., a wireless access point, through a downlink channel and transmits data and control signals to the network, i.e., the wireless access point, through an uplink channel.

The multiplexer/demultiplexer 820 multiplexes data generated by the higher layer device 830 and the control message processor 840, and demultiplexes data received by the transceiver 810 and transfers the demultiplexed data to the higher layer device 830 and/or the control message processor 840.

The control message processor 840 is an RRC layer device that processes a control message received from the network to perform necessary operations. Higher layer device 830 may be implemented per service to process data generated by user services and send the data to multiplexer/demultiplexer 820, or to process data from multiplexer/demultiplexer 820 and send the processed data to service applications on higher layers.

The controller 850 controls the transceiver 810 and the multiplexer/demultiplexer 820 according to information received through the transceiver 810. According to an embodiment of the present disclosure, the controller 850 controls to reduce the time for the UE to transmit a new location registration request or to improve efficiency by reusing a wireless connection.

Fig. 9 is a block diagram illustrating a configuration of a wireless access point (e.g., eNB) according to an embodiment of the present disclosure.

Referring to fig. 9, the eNB includes a transceiver 910, a multiplexer/demultiplexer 920, a higher layer device 930, a control message processor 940, and a controller 950.

The transceiver 910 transmits data and control signals to the UE through a downlink channel and receives data and control signals from the UE through an uplink channel. The transceiver 910 may transmit to and receive from another network entity, in particular a RAN control entity (e.g., MME), connected by a wired network according to embodiments of the present disclosure.

Multiplexer/demultiplexer 920 is responsible for multiplexing data generated by higher layer devices 930 and/or control message processor 940 and demultiplexing data received by transceiver 910 and sending the demultiplexed data to higher layer devices 930 and/or control message processor 940.

A control message processor 940 processes a control message transmitted by the UE to take necessary actions, and generates a control message addressed to the UE to a lower layer. The higher layer device 830 may be implemented as a bearer and processes data from the SGW or another eNB to generate RLC PDUs to the multiplexer/demultiplexer 920 or processes RLC PDUs from the multiplexer/demultiplexer 920 to generate PDCP SDUs to the SGW or another eNB.

The controller 950 controls the transceiver 910 and the multiplexer/demultiplexer 920 according to information received through the transceiver 910. The controller 950 releases the radio connection of the UE as soon as possible to shorten the time required for the UE to transmit a new location registration request and maintains the radio connection for a predetermined duration to reuse the radio connection in order to improve efficiency. Further, the controller 950 controls such that the UE reuses a radio connection to the secondary eNB in handover and radio connection re-establishment procedures of the UE.

As described above, the location registration method and apparatus of a terminal in a mobile communication network according to the present disclosure are advantageous in terms of efficient utilization of wireless resources in view of time reduction and resource saving.

In the various embodiments described above, all operations will be performed or selectively omitted. In each embodiment, the operations may be performed out of the order depicted, but in an altered order.

Aspects of the present disclosure can also be embodied as computer readable codes on a computer readable recording medium. The non-transitory computer readable recording medium is any data storage device that can store data which can be thereafter read by a computer system. Examples of the non-transitory computer readable recording medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, optical data storage devices, and the like. The non-transitory computer-readable recording medium can also be distributed over network-coupled computer systems so that the computer-readable code is stored and executed in a distributed fashion. In addition, functional programs, codes, and code segments for accomplishing the present disclosure can be easily construed by programmers skilled in the art to which the present disclosure pertains.

At this point it should be noted that the various embodiments of the present disclosure as described above generally relate to the processing of input data and the generation of output data to some extent. This input data processing and output data generation may be implemented in hardware or software in combination with hardware. For example, certain electronic components may be used in mobile devices or similar or related circuitry for implementing the functions associated with the various embodiments of the present disclosure as described above. Alternatively, one or more processors operating in accordance with stored instructions may implement the functions associated with the various embodiments of the disclosure as described above. If this is the case, such instructions may be stored on one or more non-transitory processor-readable media, which is within the scope of the present disclosure. Examples of a processor-readable medium include read-only memory (ROM), random-access memory (RAM), CD-ROMs, magnetic tapes, floppy disks, and optical data storage devices. The processor-readable medium can also be distributed over network-coupled computer systems so that the instructions are stored and executed in a distributed fashion. Furthermore, functional computer programs, instructions and instruction segments for implementing the present disclosure can be easily construed by programmers skilled in the art to which the present disclosure pertains.

While the disclosure has been shown and described with reference to various embodiments thereof, 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 disclosure as defined by the appended claims and their equivalents.

Claims

1. A method for adding a primary base station of a secondary base station in a communication system, the method comprising:

transmitting a secondary base station addition request message for requesting a secondary base station addition to the secondary base station, the secondary base station addition request message including a first identifier allocated by the primary base station for identifying the terminal by the primary base station, security capabilities of the terminal, and an aggregated maximum bit rate AMBR for the terminal to be used at the secondary base station; and

receiving a secondary base station addition confirmation message from the secondary base station if the secondary base station allows the secondary base station addition, the secondary base station addition confirmation message including a second identifier for the secondary base station to identify the terminal allocated by the secondary base station,

wherein the first identifier and the second identifier are used to support dual connectivity for the terminal.

2. The method of claim 1, wherein the secondary base station addition request message includes information on bearers to be served.

3. The method of claim 2, wherein the information about the bearer to be served comprises at least one of: a bearer identifier, information indicating whether a bearer is proposed for forwarding, uplink General Packet Radio Service (GPRS) tunneling protocol (GTP) tunnel endpoint information, or a bearer quality of service (QoS) parameter.

4. The method of claim 2, wherein the AMBR is used for scheduling bearers of the serving terminal by the secondary base station.

5. A method of a secondary base station in a communication system, the method comprising:

receiving a secondary base station addition request message for requesting addition of a secondary base station from a primary base station, the secondary base station addition request message including a first identifier allocated by the primary base station for identifying a terminal by the primary base station, security capabilities of the terminal, and an aggregated maximum bit rate AMBR for the terminal to be used at the secondary base station; and

transmitting a secondary base station addition confirmation message to the primary base station if the secondary base station allows the secondary base station addition, the secondary base station addition confirmation message including a second identifier for the secondary base station to identify the terminal allocated by the secondary base station,

6. The method of claim 5, wherein the secondary base station addition request message includes information about a bearer to be served.

7. The method of claim 6, wherein the information about the bearer to be served comprises at least one of: a bearer identifier, information indicating whether a bearer is proposed for forwarding, uplink General Packet Radio Service (GPRS) tunneling protocol (GTP) tunnel endpoint information, or a bearer quality of service (QoS) parameter.

8. The method of claim 6, further comprising:

and scheduling the load of the service terminal based on the AMBR.

9. A primary base station for adding a secondary base station in a communication system, the primary base station comprising:

a transceiver configured to transmit and receive signals;

a controller configured to:

10. The primary base station of claim 9, wherein the secondary base station add request message includes information about the bearer to be served.

11. The primary base station of claim 10, wherein the information about the bearer to be served comprises at least one of: a bearer identifier, information indicating whether a bearer is proposed for forwarding, uplink General Packet Radio Service (GPRS) tunneling protocol (GTP) tunnel endpoint information, or a bearer quality of service (QoS) parameter.

12. The primary base station of claim 10, wherein the AMBR is used for scheduling bearers of the serving terminal by the secondary base station.

13. A secondary base station in a communication system, the secondary base station comprising:

a transceiver configured to transmit and receive signals; and

a controller configured to:

14. The secondary base station of claim 13, wherein the secondary base station addition request message includes information about the bearer to be served.

15. The secondary base station of claim 14, wherein the information about the bearers to be served comprises at least one of: a bearer identifier, information indicating whether a bearer is proposed for forwarding, uplink General Packet Radio Service (GPRS) tunneling protocol (GTP) tunnel endpoint information, or a bearer quality of service (QoS) parameter.

16. The secondary base station of claim 14, wherein the controller is further configured to schedule bearers for the serving terminals based on the AMBR.