KR20170056864A - Method for performing cell reselection by an user equipment in wireless communication system and apparatus thereof - Google Patents

Abstract

According to the present invention, disclosed are a cell reselection method considering a service priority and an apparatus therefor. To this end, the cell reselection method includes the steps of: receiving a message including a frequency priority from a base station; and performing cell reselection based on frequency priority information. At this time, the cell reselection is performed by considering the service priority if a frequency supporting the service to be used by the terminal is considered to have the highest priority and a plurality of frequencies are considered to have the highest priority.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method and apparatus for reselecting a cell in a wireless communication system,

The present invention relates to a wireless communication system. More particularly, the present invention relates to a cell reselection method that considers service priorities and an apparatus therefor.

As an example of a wireless communication system to which the present invention can be applied, a 3GPP LTE (Third Generation Partnership Project) Long Term Evolution (LTE) communication system will be schematically described.

1 is a diagram schematically showing an E-UMTS network structure as an example of a wireless communication system. The Evolved Universal Mobile Telecommunications System (E-UMTS) system evolved from the existing Universal Mobile Telecommunications System (UMTS), and is currently undergoing basic standardization work in 3GPP. In general, E-UMTS may be referred to as an LTE (Long Term Evolution) system. For details of the technical specifications of UMTS and E-UMTS, refer to Release 7 and Release 8 of "3rd Generation Partnership Project (Technical Specification Group Radio Access Network)" respectively.

1, an E-UMTS includes an Access Gateway (AG) located at the end of a User Equipment (UE), a Node B (eNode B), and an E-UTRAN, . The base station may simultaneously transmit multiple data streams for broadcast services, multicast services, and / or unicast services.

One base station has more than one cell. The cell is set to one of the bandwidths of 1.25, 2.5, 5, 10, 15, 20Mhz and the like to provide downlink or uplink transmission service to a plurality of UEs. Different cells may be set up to provide different bandwidths. The base station controls data transmission / reception for a plurality of terminals. The base station transmits downlink scheduling information for downlink (DL) data, and notifies the UE of time / frequency region, coding, data size, and HARQ related information to be transmitted to the UE. In addition, the base station transmits uplink scheduling information to uplink (UL) data, and notifies the UE of time / frequency domain, coding, data size, and HARQ related information that the UE can use. An interface for transmitting user traffic or control traffic may be used between the base stations. The Core Network (CN) can be composed of an AG and a network node for user registration of the UE. The AG manages the mobility of the terminal in units of TA (Tracking Area) composed of a plurality of cells.

Wireless communication technologies have been developed to LTE based on WCDMA, but the demands and expectations of users and operators are continuously increasing. In addition, since other wireless access technologies are continuously being developed, new technology evolution is required to be competitive in the future. Cost reduction per bit, increased service availability, use of flexible frequency band, simple structure and open interface, and proper power consumption of terminal.

An object of the present invention is to provide an effective cell reselection method and apparatus therefor when a plurality of frequencies having the same priority are included in a wireless communication system.

A method for a UE to perform cell reselection in a wireless communication system according to an aspect of the present invention includes: receiving a message including a frequency priority from a base station; And performing cell reselection based on the frequency priority information. At this time, if the frequency supporting the service to be used by the terminal is considered to have the highest priority, and if a plurality of frequencies are regarded as having the highest priority, .

In another aspect of the present invention, a terminal apparatus in a wireless communication system includes: a memory; A communication module for receiving a message including a frequency priority from a base station; And a processor for performing cell reselection based on the frequency priority list. At this time, the processor considers that the frequency supporting the service to be used by the terminal device has the highest priority, and when a plurality of frequencies are regarded as having the highest priority, considering the service priority The cell reselection can be performed.

According to the embodiments of the present invention as described above, there is an effect of providing an effective cell reselection method and an apparatus therefor when a plurality of frequencies having the same priority in the wireless communication system are provided.

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

1 is a diagram schematically showing an E-UMTS network structure as an example of a wireless communication system.
2 is a conceptual diagram illustrating a network structure of an evolved universal terrestrial radio access network (E-UTRAN).
3 is a diagram showing a control plane and a user plane structure of a radio interface protocol between a UE and an E-UTRAN based on the 3GPP radio access network standard.
FIG. 4 is a diagram illustrating an example in which priorities of the same rank are generated.
5 is a diagram illustrating an example in which a cell reselection process is performed according to priority among services.
6 is a diagram showing an example in which a set value is manually updated.
7 is a diagram illustrating an example in which a set value is updated via a network.
8 is a diagram illustrating a format of a set value.
9 is a diagram illustrating a cell reselection process of a UE having a single RF unit.
10 is a diagram illustrating a cell reselection process of an EU with a plurality of RF units.
11 and 12 are views showing an example of cell reselection.
13 illustrates a block diagram of a communication UE according to an embodiment of the present invention.

Hereinafter, the structure, operation and other features of the present invention will be readily understood by the embodiments of the present invention described with reference to the accompanying drawings. The embodiments described below are examples in which technical features of the present invention are applied to a 3GPP system.

Although the present specification describes an embodiment of the present invention using an LTE system and an LTE-A system, embodiments of the present invention may be applied to any communication system corresponding to the above definition. In addition, although the present invention is described with reference to the FDD scheme, the embodiments of the present invention can be easily modified to the H-FDD scheme or the TDD scheme.

2 is a conceptual diagram illustrating a network structure of an evolved universal terrestrial radio access network (E-UTRAN). Especially, the E-UTRAN system is an evolved system in the existing UTRAN system. The E-UTRAN is composed of cells (eNBs), and the cells are connected via the X2 interface. The cell is connected to the terminal through the air interface, and is connected to the EPC (Evolved Packet Core) through the S1 interface.

EPC is composed of MME (Mobility Management Entity), S-GW (Serving-Gateway) and PDN-GW (Packet Data Network-Gateway). The MME has information on the access information of the terminal or the capability of the terminal, and this information is mainly used for managing the mobility of the terminal. The S-GW is a gateway having an E-UTRAN as an end point, and the PDN-GW is a gateway having a PDN (Packet Data Network) as an end point.

3 is a diagram showing a control plane and a user plane structure of a radio interface protocol between a UE and an E-UTRAN based on the 3GPP radio access network standard. The control plane refers to a path through which control messages used by a UE and a network are transferred. The user plane means a path through which data generated in the application layer, for example, voice data or Internet packet data, is transmitted.

The physical layer as the first layer provides an information transfer service to an upper layer using a physical channel. The physical layer is connected to a medium access control layer (upper layer) through a transport channel. Data moves between the MAC layer and the physical layer over the transport channel. Data is transferred between the transmitting side and the receiving side physical layer through the physical channel. The physical channel utilizes time and frequency as radio resources. Specifically, the physical channel is modulated in an OFDMA (Orthogonal Frequency Division Multiple Access) scheme in a downlink, and is modulated in an SC-FDMA (Single Carrier Frequency Division Multiple Access) scheme in an uplink.

The Medium Access Control (MAC) layer of the second layer provides a service to a radio link control (RLC) layer, which is an upper layer, through a logical channel. The RLC layer of the second layer supports reliable data transmission. The function of the RLC layer may be implemented as a functional block in the MAC. The Packet Data Convergence Protocol (PDCP) layer of the second layer performs a header compression function to reduce unnecessary control information in order to efficiently transmit IP packets such as IPv4 and IPv6 in a wireless interface with a narrow bandwidth.

The Radio Resource Control (RRC) layer located at the bottom of the third layer is defined only in the control plane. The RRC layer is responsible for the control of logical channels, transport channels and physical channels in connection with the configuration, re-configuration and release of radio bearers (RBs). RB denotes a service provided by the second layer for data transmission between the UE and the network. To this end, the terminal and the RRC layer of the network exchange RRC messages with each other.

One cell constituting the base station eNB is set to one of the bandwidths of 1.25, 2.5, 5, 10, 15, 20Mhz and the like to provide a downlink or uplink transmission service to a plurality of terminals. Different cells may be set up to provide different bandwidths.

A downlink transmission channel for transmitting data from a network to a terminal includes a BCH (Broadcast Channel) for transmitting system information, a PCH (Paging Channel) for transmitting a paging message, a downlink SCH (Shared Channel) for transmitting user traffic or control messages, have. In case of a traffic or control message of a downlink multicast or broadcast service, it may be transmitted through a downlink SCH, or may be transmitted via a separate downlink multicast channel (MCH).

Meanwhile, the uplink transmission channel for transmitting data from the UE to the network includes a random access channel (RACH) for transmitting an initial control message and an uplink SCH (shared channel) for transmitting user traffic or control messages. A logical channel mapped to a transport channel is a broadcast control channel (BCCH), a paging control channel (PCCH), a common control channel (CCCH), a multicast control channel (MCCH) Traffic Channel).

Hereinafter, the RRC state of the UE and the RRC connection method will be described. The RRC state refers to whether or not the RRC of the UE is a logical connection with the RRC of the E-UTRAN. If the RRC is connected, the RRC connection state (RRC_CONNECTED) is established. If not, the RRC idle state (RRC_IDLE) .

Since the E-UTRAN can grasp the presence of the UE in the RRC-connected state on a cell-by-cell basis, the E-UTRAN can effectively control the UE. On the other hand, the E-UTRAN can not grasp the RRC idle terminal in the cell unit, and the CN manages the TA unit, which is a larger area unit than the cell. That is, in order for the UE in the RRC idle state to receive services such as voice or data from the cell, the UE must transition to the RRC connected state.

In particular, when the user first turns on the power of the UE, the UE first searches for an appropriate cell and stays in the RRC idle state in the cell. The UE which has stayed in the RRC idle state performs the RRC connection establishment process with the RRC of the E-UTRAN only when it is necessary to establish the RRC connection, and transits to the RRC connection state. Here, the case where the RRC connection needs to be established means that uplink data transmission is required due to a user's call attempt or the like, or when a paging message is received from the E-UTRAN, a response message should be transmitted.

The cell selection and the cell reselection process will be described below.

When the terminal is powered on, the terminal must select cells of appropriate quality and perform preparatory procedures to receive the service. A terminal in RRC idle state should always select a cell of appropriate quality and prepare to receive service through this cell. For example, a powered down terminal must select a cell of the appropriate quality to register with the network. When the UE in the RRC connection state enters the RRC idle state, the UE must select a cell to stay in the RRC Idle state. In this manner, the process of selecting a cell satisfying a specific condition in order to stay in a service waiting state such as the RRC idle state is called a cell selection.

Importantly, cell selection is performed in a state in which the UE has not currently determined to be in the RRC idle state, so it is most important to select the cell as quickly as possible. Therefore, even if the cell provides the best radio signal quality to the UE, it can be selected in the cell selection process of the UE.

When the UE selects a cell satisfying the cell selection criterion, the UE receives information required for operation in the RRC idle state of the UE in the corresponding cell from the system information of the corresponding cell. After receiving all information necessary for operation in the RRC idle state, the UE waits in the RRC idle state in order to request the service from the network or receive the service from the network.

Once the UE has selected a cell through the cell selection process, the strength or quality of the signal between the UE and the BS may be changed due to mobility of the UE or change of the radio environment. Thus, if the quality of the selected cell degrades, the terminal may select another cell that provides better quality. When the cell is reselected in this way, a cell is selected that generally provides better signal quality than the currently selected cell. This process is called cell reselection.

The cell reselection process has a basic purpose in terms of quality of a radio signal, in general, to select a cell that provides the best quality to the terminal. In addition to the quality of the radio signal, the network can determine the priority for each frequency and notify the terminal. The MS receiving the priority order takes priority over the radio signal quality reference in the cell reselection process.

The cell reselection procedure can be classified as shown in Table 1 according to the radio access technology (RAT) of the cell and the frequency characteristics.

Intra-frequency cell reselection A cell with a center-frequency such as RAT like a serving cell is reselected Inter-frequency cell reselection Cells with a different center frequency than the RAT like the serving cell are reselected Inter-RAT cell reselection Reselect a cell using a different RAT from the RAT being used in the serving cell

The UE may receive the frequency priority through the system information or the RRC connection release message, or may receive it from another RAT when the Inter-RAT cell is reselected.

In one example, the UE may receive system information indicating the priority of the E-UTRAN frequency or the Inter RAT frequency through the RRC disconnect message.

However, the frequency priority indicated by the system information is not always a priority. The UE may ignore the frequency priority indicated by the system information and perform the cell reselection process according to the current state or service currently being used.

For example, it is assumed that the UE desires to use a CSG (Closed Subscriber Group) service. If the cell in which the UE is staying is a suitable CSG cell, the UE may consider the current frequency to be the highest priority and perform cell reselection. Alternatively, if the current resident cell is not a CSG cell and a CSG cell is found at a frequency different from the serving frequency, the UE may determine the frequency at which the CSG cell found the highest priority It is possible to perform cell reselection while considering it as being.

Next, it is assumed that the UE desires to use Multimedia Broadcast and Multicast Service (MBMS). If the MBMS is available only at the frequency of the cell where the UE is staying, the UE may consider the current frequency to be the highest priority and perform cell reselection.

Next, it is assumed that the UE desires to use a Proximity-based Service (ProSe) service. If ProSe Direct Communication is possible only at the frequency of the cell where the UE is staying, the UE can consider the current frequency to be the highest priority and perform cell reselection. Alternatively, if it is desired to perform ProSe direct communication at a frequency different from the serving frequency, the UE may measure any frequency for cell reselection. At this time, if the measurement result of the frequency satisfies the S criterion, the UE can regard the ProSe of the corresponding frequency as In coverage. In this case, a UE supporting one RF will be able to reselect a cell supporting that frequency.

As illustrated above, if the UE is in a state capable of performing a specific service (e.g., a CSG service, an MBMS service, or a ProSe direct communication service) in a cell where the current cell is reselected during Inter-frequency cell reselection, The frequency of the current cell can be regarded as having the highest priority. Alternatively, if a certain service can not be performed in the currently staying cell, the cell reselection can be performed while considering that the frequency of the target cell in which the specific service is available has the highest priority.

However, when the UE desires to support a plurality of services, different frequencies may simultaneously have the highest priority. For example, it is assumed that the UE desires to use both the CSG service and the ProSe service. At this time, if the cell in which the UE is staying is in a state in which ProSe direct communication is possible, the UE will regard the current cell frequency as having the highest priority. However, if the CSG service is not available at the serving frequency and the CSG service is available at other frequencies, frequencies other than the serving frequency should also be considered as the highest priority.

When selecting any one of a plurality of frequencies having the same priority (i.e., a plurality of frequencies having the highest priority at the same time), one of the services can be used while the other is used A problem may arise in which it can not be performed. For example, if the UE selects the current cell (i.e., a cell capable of direct ProSe communication) through a cell reselection process, ProSe direct communication will be available but the CSG will not be available. Alternatively, if the UE chooses a CSG cell, connectivity to ProSe direct communication will be interrupted.

For example, FIG. 4 is a diagram illustrating an example in which priorities of the same rank are generated. It is assumed that the frequency priority indicated by the system information has 8 grades of 0 to 7 levels.

Referring to FIG. 4, a state A indicates a case where a cell reselection is performed by comparing a frequency priority of a serving cell and a frequency priority of a target cell indicated by the system information by the UE. For example, when both the serving cell and the target cell are legacy cells, and the serving cell and the target cell both support the CSG service when the UE intends to use the CSG service, when the UE desires to use the MBMS service, And the target cell supports ProSe direct communication when the UE supports the MBMS, and the UE desires to use the ProSe direct communication service. In state A, the UE may compare the frequency priorities of the serving cell and the target cell and reselect the cell with the highest priority.

The B state is an example showing a state in which the frequency priority of the target cell is assumed to be high assumption. For example, if the serving cell is a legacy cell and the target cell supports a CSG, MBMS, or ProSe direct communication service when the UE is in a state of using a CSG, MBMS, or ProSe direct communication service, Is considered to have the highest priority (in FIG. 4, the frequency priority of the target cell is set to 8, which is greater than the frequency priority (0 to 7) indicated by the system information) . In this case, the UE will select the target cell through the cell reselection process.

C state is an example showing a state in which the frequency priority of the serving cell is considered to be the highest. For example, if the target cell is a legacy cell and the serving cell supports a CSG, MBMS, or ProSe direct communication service when the UE is in a state of using a CSG, MBMS, or ProSe direct communication service, (In FIG. 4, the frequency priority of the serving cell is shown as being set to 8, which is higher than the frequency priority (0 to 7) indicated by the system information), to perform cell reselection . In this case, the UE will select a serving cell through a cell reselection process.

D state is an example in which both the priority of the serving cell and the frequency priority of the target cell are considered to have the highest priority.

When the UE is in a state in which two or more services are to be used simultaneously and the serving cell supports one service and the target cell supports another service, the frequency priorities of the serving cell and the target cell are both It can be regarded as having the highest priority. For example, in FIG. 4, the priorities of the serving cell and the target cell are all considered to be eight.

As described above, if there are a plurality of frequencies in the same order, if the UE selects any one of frequencies having the same order, the user may not be able to guarantee continuity of the desired service.

Accordingly, the present invention proposes a method of setting a priority among a plurality of services and performing a cell reselection according to a setting when a plurality of frequencies having the same priority are used.

According to the present invention, the UE can store a setting value that sets priority among services. When there are a plurality of frequencies having the same priority in re-frequency cell re-routing, the UE can select any one of the plurality of frequencies according to the inter-service priority indicated by the set value.

For example, FIG. 5 illustrates an example in which a cell reselection process is performed according to priority among services. If the UE remains in the RRC idle state (or normally state) (S501), the UE may perform measurements on neighboring cells (S502).

At this time, if the target frequency is an Intra-Frequency having a center frequency equal to the center RAT of the serving cell (S503), the UE may perform intra-frequency cell reselection (S504).

If the target frequency is not an intra frequency, the UE may compare frequency priority (S505). At this time, if the priority of the target frequency is higher than the priority of the serving frequency, the UE can reselect the target cell having the target frequency through an inter-frequency cell reselection process (S506). Alternatively, if the priority of the target frequency is lower than the priority of the serving frequency, the UE may reselect the serving cell and maintain the RRC idle state.

If the target frequency and the serving frequency have the same priority, the UE can perform the cell reselection process in consideration of the service priority (S507) (S506). If the priority of the service provided by the target cell (that is, the service available on the target frequency) is higher than the priority of the service provided on the serving cell (i.e., a service available on the serving frequency) The target cell having the target frequency can be reselected through the intercell re-selection process. Alternatively, if the priority of the service provided by the target cell is lower than the priority of the service provided by the serving cell, the UE may reselect the serving cell and maintain the RRC idle state.

The setting value indicating the service priority can be stored in the UE through a memory such as a UICC or NVMEM. The inter-service priority indicated by the set value can be manually updated by user input. That is, the UE can set priority among services by user input received through a user interface such as a user input received through an application or an AT command.

6 is a diagram showing an example in which a set value is manually updated. As in the example shown in Fig. 5, at the application end, when a request to update the setting value occurs, the setting value stored in the memory can be updated. At this time, the update request may include information such as a service list, service support status, service status, and service priority. A detailed description of each item will be given later.

As another example, the setting value is set in advance to indicate the priority among services before the product launch, and is stored in a memory such as UICC, NVMEM, etc., and the set value is set by the OMA (Open Mobile Alliance) DM As shown in FIG. Here, OMA means a service application standard for mobile communication field, and DM means a technology for remotely accessing and managing data in a terminal.

For example, FIG. 7 shows an example in which a set value is updated through a network. Service Priority When a request to update a configuration value occurs in the server, the network can send an OMA DM push message to request service priority update via TCP / IP via OMA DM. When a push alert is received from the network, the UE may update the settings stored in the memory according to the service priority update request. At this time, the update request may include information such as a service list, service support status, service status, and service priority. Each item will be described with reference to Fig.

8 is a diagram illustrating a format of a set value.

The memory may store settings including a service name, service availability, service status, and service priority. The setting value may be updated by a user input occurring at the application terminal, or may be updated according to an update request received through the OMA DM.

In the example shown in FIG. 8, the service name indicates the name of a service such as a ProSe direct communication service, a CSG service, or an MBMS service.

Service Support indicates whether or not a specific service is supported. The UE can set whether to support the service or not, separately from whether or not the UE has the capability to support the specific service. A service set in an unsupported state can be regarded as having the lowest priority, ignoring service priorities to be described later. For example, if the GSC service, the ProSe direct communication service, the CSG of the MBMS service, and the ProSe direct communication service are set to the supported state and the MBMS is set to the unsupported state, the MBMS ignores the priority specified in the service priority, It can be regarded as having a ranking. Whether the service is supported / not supported for a specific service may be manually changed by user input.

The service state indicates whether to consider the state of the service when the cell is reselected. For example, in the case of the MBMS, the priority between services may be considered by distinguishing between an on-service state and an interest state. For example, the MBMS service may have a higher service priority than the specific service while the MBMS service state may have a lower service priority than the specific service.

The service priority can indicate the priority among the services.

In specifying the priority among services, whether or not a specific service is available in a dormant state or whether or not a service is being used can be considered.

For example, ProSe direct communication may be set to have the highest service priority because it is a service used for public safety purposes and is available in a dormant state. MBMS can be used even in a dormant state, but it can be set to have a lower service priority than ProSe direct communication since MBMS is a service used for entertainment purposes, as compared with ProSe direct communication service.

Since the CSG service is available only in the RRC connection state, it can be set to have a lower service priority than the available ProSe direct communication service and MBMS even in the RRC idle state.

However, the MBMS may be set to have a service priority higher than that of the CSG service in the on-service state, and may be set to have a lower service priority in the interest state than the CSG service in the on-service state . By lowering the service priority in the MBMS state of interest to that of the CSG service, it is possible to induce a closed subscriber service rather than a wide area service.

According to the above example, the service priority can be defined as follows.

- When the service status is not considered: ProSe direct communication service> MBMS> CSG

- Considering the service status: ProSe direct communication service> MBMS (on service)> CSG> MBMS (interest)

In the following embodiments, it is assumed that the priority among the services is the same as the above definition.

In setting the priority among the services, the capabilities of the UE (the number of RF units) and the service characteristics may be considered.

For example, FIGS. 9 and 10 illustrate a cell reselection process according to the number of RF units when a plurality of frequencies have the highest priority at the same time. A cell reselection process according to the number of RF units will be described with reference to the following drawings.

9 is a diagram illustrating a cell reselection process of a UE having a single RF unit.

If a plurality of frequencies have the highest priority at the same time, the UE may read the setting values from the memory (S901). If the inter-service priority is set in consideration of the state of the service (for example, the inter-service priority is set by distinguishing the MBMS on-service and the MBMS interested state) (S902) The cell reselection can be performed in consideration of the service and its state, the service supported by the target cell, and its state (S903).

Alternatively, if the service state is not set in consideration (S902), the UE can select a cell supporting a service having a high service priority among services supported by the serving cell and services supported by the target cell (S904).

Table 2 below summarizes the process of cell reselection of a UE with a single RF unit.

Target
Serving CSG ProSe CSG Cell reselection according to frequency priority Same priority among frequencies
(Same rank occurrence) → CSG  < ProSe ProSe Frequency equal priority occurs → ProSe> CSG Cell reselection according to frequency priority MBMS Same priority among frequencies
→ MBMS InService  > CSG  > MBMS Interested Same priority among frequencies
→ MBMS  < ProSe

10 is a diagram illustrating a cell reselection process of an EU with a plurality of RF units.

A particular service (eg, ProSe direct communication service, etc.) that is also available through a non-serving frequency that is not a serving frequency may be set to prioritize the non-serving frequency.

For example, if the currently resident cell is a suitable CSG cell, it is possible to select a cell that supports ProSe direct communication service at a non-serving frequency, without reselecting a cell capable of ProSe direct communication. Fig. 11 shows an example in which reselection is not performed.

As described above, if the specific service can be supported through the non-serving frequency of the target cell (S1003), the UE considers that the priority of the serving cell is higher than the priority of the target cell and can reselect the cell that is currently staying (S1004 ).

If the cell in which the current resident cell is a cell capable of direct communication with ProSe and a target cell supporting the CSG service is found at a frequency other than the current serving frequency, the target cell is reselected and the ProSe direct communication service is supported at the non- You can select a cell. Fig. 12 shows an example in which reselection is performed.

As described above, if the specific service can be supported through the non-serving frequency of the serving cell (S1001), the UE can regard the serving cell as having a priority lower than the priority of the target cell and reselect the target cell (S1002) .

If there is no service capable of supporting through the non-serving frequency, the UE may read the setting value from the memory (S1005). If priority among services is set (for example, MBMS on-service and MBMS interest states are classified and priority among services is set) (S1006) in consideration of the service status, The cell reselection can be performed in consideration of the service and its state, the service supported by the target cell and its state (S1007).

Alternatively, if the service state is not set in consideration (S1006), the UE can select a cell supported by the serving cell and a service supported by the target cell, which support the service having a high service priority (S1008).

Table 3 below is an example of a cell reselection process of a UE having a plurality of RF units.

Target
Serving CSG ProSe CSG Cell reselection according to frequency priority Same priority among frequencies
→ NoReselection: CSG (serving), ProSe (nonServing) ProSe Same priority among frequencies
→ Reselection: ProSe (nonServing), CSG (serving) Cell reselection according to frequency priority MBMS Same priority among frequencies
→ MBMS InService>CSG> MBMS Interested NoReselection: MBMS (serving), ProSe (nonServing)

13 illustrates a block diagram of a communication UE according to an embodiment of the present invention.

13, the UE includes a processor 1310, a memory 1320, at least one RF module 1330, a display module 1340, and a user interface module 1350.

The UE does not have to include all of the illustrated components, and some of the modules may be omitted. In addition, the UE may further include necessary modules. Also, some of the modules in the UE can be divided into more subdivided modules. The processor 1310 is configured to perform operations according to embodiments of the present invention illustrated with reference to the figures.

Specifically, the processor 1310 may generate a control signal and perform mapping to a control channel set in a plurality of frequency blocks. The processor 1310 may also identify the control channel indicated to it from the received signal from the plurality of frequency blocks and extract the control signal therefrom.

The processor 1310 may then perform the required operation based on the control signal. As an example, the processor 1310 may reselect the cell in consideration of frequency priority and service priority. The detailed operation of the processor 1310 may refer to the contents described in Figs.

The memory 1320 is coupled to the processor 1310 and stores an operating system, applications, program code, data, and the like. Specifically, the memory 1320 may store a setting value indicating a service priority.

The RF module 1330 is connected to the processor 1310 and performs a function of converting a baseband signal into a radio signal or a radio signal into a baseband signal. To this end, the RF module 1330 performs analog conversion, amplification, filtering, and frequency up conversion, or inverse thereof.

Display module 1340 is coupled to processor 1310 and displays various information. The display module 1340 may use well known elements such as, but not limited to, a Liquid Crystal Display (LCD), a Light Emitting Diode (LED), and an Organic Light Emitting Diode (OLED).

The user interface module 1350 is connected to the processor 1310 and may be configured as a combination of well known user interfaces such as a keypad, a touch screen, and the like.

The embodiments described above are those in which the elements and features of the present invention are combined in a predetermined form. Each component or feature shall be considered optional unless otherwise expressly stated. Each component or feature may be implemented in a form that is not combined with other components or features. It is also possible to construct embodiments of the present invention by combining some of the elements and / or features. The order of the operations described in the embodiments of the present invention may be changed. Some configurations or features of certain embodiments may be included in other embodiments, or may be replaced with corresponding configurations or features of other embodiments. It is clear that the claims that are not expressly cited in the claims may be combined to form an embodiment or be included in a new claim by an amendment after the application.

In this document, the embodiments of the present invention have been mainly described with reference to the data transmission / reception relationship between the terminal and the base station. The specific operation described herein as being performed by the base station may be performed by its upper node, in some cases. That is, it is apparent that various operations performed for communication with a terminal in a network including a plurality of network nodes including a base station can be performed by a network node other than the base station or the base station. A base station may be replaced by terms such as a fixed station, a Node B, an eNode B (eNB), an access point, and the like. In addition, the terminal may be replaced by terms such as a UE (User Equipment), a Mobile Station (MS), and a Mobile Subscriber Station (MSS).

Embodiments in accordance with the present invention may be implemented by various means, for example, hardware, firmware, software, or a combination thereof. In the case of hardware implementation, an embodiment of the present invention may include one or more application specific integrated circuits (ASICs), digital signal processors (DSPs), digital signal processing devices (DSPDs), programmable logic devices (PLDs) field programmable gate arrays, processors, controllers, microcontrollers, microprocessors, and the like.

In the case of an implementation by firmware or software, an embodiment of the present invention may be implemented in the form of a module, a procedure, a function, or the like which performs the functions or operations described above. The software code can be stored in a memory unit and driven by the processor. The memory unit may be located inside or outside the processor, and may exchange data with the processor by various well-known means.

It will be apparent to those skilled in the art that the present invention may be embodied in other specific forms without departing from the spirit of the invention. Accordingly, the above description should not be construed in a limiting sense in all respects and should be considered illustrative. The scope of the present invention should be determined by rational interpretation of the appended claims, and all changes within the scope of equivalents of the present invention are included in the scope of the present invention.

1310: Processor
1320: Memory
1330: RF module
1340: Display module
1350: User Interface Module

Claims (10)

A method for a UE to perform cell reselection in a wireless communication system,
Receiving a message including a frequency priority from a base station; And
And performing cell reselection based on the frequency priority information,
The frequency supporting the service to be used by the terminal is regarded as having the highest priority,
And when the plurality of frequencies are regarded as having the highest priority, the cell reselection is performed in consideration of the service priority. The method according to claim 1,
Wherein the service priority is set to a ProSe direct communication service, an MBMS, and a CSG service order. The method according to claim 1,
Wherein the first service is variable in service priority according to the service status. The method of claim 3,
Wherein the first service is an MBMS service,
In the on-service state, the MBMS has a higher priority than the second service,
Wherein, in a state of interest, the MBMS has a lower priority than the second service. The method according to claim 1,
Wherein the terminal stores a setting value indicating the service priority. 6. The method of claim 5,
Wherein the set value is manually updated by user input. The method according to claim 6,
And the set value is updated via OMA DM. 6. The method of claim 5,
Wherein the setting value includes at least one of service name information, service support information, service status information, and service priority information. 9. The method of claim 8,
The service support information indicates whether or not the terminal supports each service and the service that the terminal does not support is considered to have the lowest priority by disregarding the service priority indicated by the service priority information . A terminal apparatus in a wireless communication system,
Memory;
A communication module for receiving a message including a frequency priority from a base station; And
A processor for performing cell reselection based on the frequency priority list,
, &Lt; / RTI &
The processor considers that the frequency supporting the service to be used by the terminal device has the highest priority, and when a plurality of frequencies are regarded as having the highest priority, And performs the reselection.

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