HK1110733B

HK1110733B - Transmitting/receiving point-to-multipoint service in wireless communication system

Info

Publication number: HK1110733B
Application number: HK08101269.4A
Authority: HK
Inventors: 李英大; 千成德
Original assignee: Lg电子株式会社
Priority date: 2004-09-24
Filing date: 2005-08-29
Publication date: 2011-02-25

Description

Transmitting/receiving point-to-multipoint service in wireless communication system

Technical Field

The present invention relates generally to wireless communication systems, and more particularly, to switching point-to-multipoint services.

Background

Fig. 1 is a block diagram illustrating a UMTS (universal mobile telecommunications system) network structure.

Referring to fig. 1, the UMTS system includes a terminal (user equipment (UE)), a UMTS Terrestrial Radio Access Network (UTRAN), and a Core Network (CN). The UTRAN includes at least one Radio Network Subsystem (RNS). Each RNS includes one Radio Network Controller (RNC) and at least one base station (e.g., node B) managed by the RNC. There is at least one cell for each node B.

Fig. 2 is a diagram illustrating a radio interface protocol structure between a terminal and a UTRAN. Thus, fig. 2 depicts a radio interface protocol structure based on the 3GPP (third generation partnership project) radio access network technical specification between the terminal and the UTRAN.

Referring to fig. 2, a radio interface protocol is horizontally arranged to include a physical layer, a data link layer, and a network layer. In addition, the radio interface protocol is vertically divided into a user plane for data information transfer and a control plane for signaling transfer. The protocol layers may also be divided into L1 (first layer), L2 (second layer), and L3 (third layer) based on the lower three layers of the Open System Interconnection (OSI) model.

The first layer or physical layer provides an information transfer service to an upper layer using a physical channel. The physical layer is connected to an upper layer called a Medium Access Control (MAC) layer via a transport channel. Data is transferred between the MAC layer and the physical layer via a transport channel. Data is also transferred between different physical layers, i.e., between physical layers of a transmitting side and a receiving side, via a physical channel.

The MAC layer of the second layer provides an upper layer called a radio link control layer with a service via a logical channel. A Radio Link Control (RLC) layer of the second layer supports reliable data transmission, and performs segmentation and concatenation on Service Data Units (SDUs) received from an upper layer.

A Radio Resource Control (RRC) layer, which is on the lower portion of the L3 layer, is defined in the control plane and controls logical channels, transport channels, and physical channels for configuration, reconfiguration, and release of Radio Bearers (RBs). The RB is a service provided by the second layer for data transmission between the terminal and the UTRAN. The configuration of the RB includes defining characteristics of protocol layers and channels required to provide a specific service, and configuring corresponding specific parameters and operation methods.

Multimedia broadcast/multicast service (MBMS) is described as follows.

The MBMS provides a data stream or background service (background service) to a plurality of UEs using a downlink-dedicated MBMS bearer service. The MBMS includes at least one session. MBMS data is transmitted to a plurality of UEs via an MBMS bearer service during an ongoing session.

The UTRAN provides the MBMS bearer service to the UE using Radio Bearers (RBs). A point-to-point radio bearer is a bidirectional radio bearer and comprises a logical channel DTCH (dedicated traffic channel), a transport channel DCH (dedicated channel) and a physical channel DPCH (dedicated physical channel) or a physical channel SCCPCH (secondary common control physical channel). The point-to-multipoint radio bearer is a unidirectional downlink. The point-to-multipoint radio bearer includes a logical channel MTCH (MBMS traffic channel), a transport channel FACH (forward access channel), and a physical channel SCPCH. The logical channel MTCH is configured for each MBMS provided to a cell and is used to transmit user plane data related to a specific MBMS to a plurality of UEs.

Fig. 3 is a diagram illustrating an example of channel mapping for a terminal to receive a point-to-multipoint service.

Referring to fig. 3, a logical channel MCCH (MBMS control channel) is a point-to-multipoint downlink channel and is used to transmit control information related to MBMS. The logical channel MCCH is mapped to a transport channel FACH (forward access channel) which is mapped to a physical channel SCCPCH (secondary common control physical channel). There is at least one MCCH within one cell.

The UTRAN providing the MBMS transmits MCCH information to a plurality of UEs via the MCCH channel. The MCCH information includes a notification message related to the MBMS (e.g., an RRC message related to the MBMS). For example, the MCCH information may include a message providing MBMS information notification, a message providing point-to-multipoint radio bearer information notification, and/or access information providing EEC connection notification required for a specific MBMS.

Fig. 4 is a diagram illustrating control information transmission for a point-to-multipoint service.

Referring to fig. 4, the MCCH information is periodically transmitted according to a modification period and a repetition period. The MCCH information is divided into critical (critical) information and non-critical (non-critical) information. Among the critical information and the non-critical information, the non-critical information may be modified at a modification period or a repetition period. However, the modification of the critical information can be performed only at the modification period. Accordingly, the critical information is repeated once during each repetition period so as to be transmitted. However, the transmission of the modified critical information may occur only at the start of the modification period.

The UTRAN periodically transmits a physical channel MICH (MBMS notification indicator channel) to indicate whether the MCCH information is updated in the modification period. Therefore, before a session of a specific MBMS service starts, UEs attempting to receive only the specific MBMS do not receive the MCCH or MTCH. However, the UE periodically receives MICH (MBMS notification indicator channel). The updating of the MCCH information is the generation, addition, modification and/or removal of a specific item of the MCCH information.

Once a session of a specific MBMS starts, the UTRAN transmits an NI (notification indicator). The NI is an indicator that provides a notification of receiving the MCCH channel to a UE attempting to receive a specific MBMS. Upon receiving the NI via the MICH, the UE receives the MCCH during a specific modification period indicated by the MICH.

A UE attempting to receive a specific MBMS using a point-to-multipoint radio bearer receives MCCH information including radio bearer information via an MCCH and then configures the point-to-multipoint radio bearer using the received information. After configuring the point-to-multipoint radio bearer, the UE continues to receive a physical channel SCCPCH, to which the MTCH is mapped, in order to obtain data related to the specific MBMS transmitted via the MTCH.

Fig. 5 is a diagram illustrating transmission of point-to-multipoint service data and scheduling information.

Referring to fig. 5, the UTRAN may discontinuously transmit MBMS data via the MTCH. In doing so, the UTRAN periodically transmits a scheduling message to the UE via the SCCPCH (SCCPCH carrying MTCH) to which the MTCH is mapped. In this case, the scheduling message provides a transmission start time point and a transmission section (section) of MBMS data transmitted during one scheduling period. For this, the UTRAN informs the UE of a transmission period (scheduling period) of scheduling information.

The UE obtains a scheduling period from the UTRAN and receives a scheduling message periodically according to the obtained scheduling period. Then, the UE discontinuously and periodically receives the SCCPCH (SCCPCH carrying MTCH) to which the MTCH is mapped using the received scheduling message. Accordingly, using the scheduling message, the UE receives the SCCPCH carrying the MTCH during a period in which data is transmitted, but does not receive the SCCPCH carrying the MTCH during a period in which data is not transmitted.

However, in the conventional method, the UE continues to periodically receive the scheduling message even though there is no data transmission for several scheduling periods. Accordingly, UE resources, such as battery power, may be wasted. In addition, the UE periodically checks the scheduling message regardless of the presence or absence of data transmission. Without data transmission, the UE may not need to receive the SCCPCH carrying MTCH. However, in such a case, the UE still needs to periodically check the scheduling message. Therefore, the UE may consume UE resources to receive the SCCPCH carrying MTCH.

Disclosure of Invention

Accordingly, the present invention is directed to communication of a point-to-multipoint service that substantially obviates one or more problems due to limitations and disadvantages of the related art.

An object of the present invention is to provide communication for a point-to-multipoint service in which a network transmits reception reservation information to a UE to delay reception of a scheduling message. Thus, the present invention may conserve UE resources, such as battery power.

Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention. The objectives and other advantages of the invention will be realized and attained by the structure particularly pointed out in the written description and claims hereof as well as the appended drawings.

To achieve these objects and other advantages and in accordance with the purpose of the invention, as embodied and broadly described herein, in one embodiment, a method of controlling a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system includes: a point-to-multipoint service is received from a network over a physical channel. The method also includes receiving a first scheduling indicator associated with a plurality of scheduling periods in which there is no transmission associated with the point-to-multipoint service, wherein each of the scheduling periods is associated with one scheduling indicator. The method further comprises receiving the point-to-multipoint service via a physical channel after said plurality of scheduling periods in which there is no transmission. The point-to-multipoint service and the first scheduling indicator are received on the same physical channel.

The method may further comprise receiving a second scheduling indicator after said plurality of scheduling periods in which there is no transmission. The method may further include receiving a point-to-multipoint service via the physical channel in response to the second scheduling indicator.

The same physical channel may include a common physical channel. The common physical channel may include a SCCPCH (secondary common physical channel). The point-to-multipoint service, the first scheduling indicator and the second scheduling indicator may be received on different logical channels. The first scheduling indicator and the second scheduling indicator may be received on the same logical channel. The point-to-multipoint service may be received on an MTCH (MBMS traffic channel). Alternatively, the point-to-multipoint service is received on a different type of logical channel. The network may be a UTMS terrestrial radio network (UTRAN).

In another embodiment, a method in a network for controlling a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system, the method comprising: the method includes transmitting a point-to-multipoint service on a physical channel and determining a plurality of scheduling periods in which there is no transmission related to the point-to-multipoint service. The method also includes transmitting a first scheduling indicator associated with the plurality of scheduling periods where there is no transmission, wherein each scheduling period is associated with a scheduling indicator. The method also includes transmitting the physical channel after a plurality of scheduling periods in which there is no transmission. The method further comprises transmitting the point-to-multipoint service via a physical channel after said plurality of scheduling periods in which there is no transmission. The point-to-multipoint service and the first scheduling indicator are transmitted on the same physical channel. The method may further comprise transmitting a second scheduling indicator after said plurality of scheduling periods in which there is no transmission.

According to an aspect of the present invention, a method of controlling a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system, the method comprising:

receiving a point-to-multipoint service from a network on a physical channel;

receiving a first scheduling indicator at a current scheduling period, the first scheduling indicator indicating a plurality of scheduling periods where there is no transmission related to the point-to-multipoint service, wherein the plurality of scheduling periods occur after the current scheduling period; and

receiving a point-to-multipoint service via a physical channel after the plurality of scheduling periods where there is no transmission;

wherein the point-to-multipoint service and the first scheduling indicator are received on the same physical channel.

According to another aspect of the present invention, there is also provided a method in a network for controlling a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system, the method comprising:

transmitting the point-to-multipoint service on a physical channel;

determining a plurality of scheduling periods where there is no transmission related to the point-to-multipoint service;

receiving a first scheduling indicator at a current scheduling period, the first scheduling indicator indicating the plurality of scheduling periods that do not contain transmissions related to the point-to-multipoint service, wherein the plurality of scheduling periods that do not contain transmissions related to the point-to-multipoint service occur after the current scheduling period; and

transmitting the point-to-multipoint service via the physical channel after the plurality of scheduling periods where there is no transmission;

wherein the point-to-multipoint service and the first scheduling indicator are transmitted on the same physical channel.

According to another aspect of the present invention, there is also provided a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system, the UE comprising:

means for receiving the point-to-multipoint service from a network on a physical channel;

means for receiving a first scheduling indicator at a current scheduling period, the first scheduling indicator indicating the plurality of scheduling periods that do not contain transmissions related to the point-to-multipoint service, wherein the plurality of scheduling periods that do not contain transmissions related to the point-to-multipoint service occur after the current scheduling period; and

means for receiving the point-to-multipoint service via a physical channel after the plurality of scheduling periods in which there is no transmission;

The above and other objects, features, aspects and advantages of the present invention will become more apparent from the following detailed description when taken in conjunction with the accompanying drawings. It is to be understood that both the foregoing general description and the following detailed description are exemplary and explanatory and are intended to provide further explanation of the invention as claimed.

Drawings

The accompanying drawings, which are included to provide a further understanding of the invention and are incorporated in and constitute a part of this application, illustrate embodiment(s) of the invention and together with the description serve to explain the principle of the invention.

Fig. 1 is a block diagram illustrating the structure of a UMTS network.

Fig. 2 is a diagram illustrating a radio interface protocol structure between a terminal and a UTRAN.

Fig. 3 is a diagram illustrating an example of channel mapping for receiving a point-to-multipoint service by a terminal.

Fig. 6 is a diagram illustrating transmission/reception of a point-to-multipoint service according to one embodiment of the present invention.

Fig. 7 is a flowchart illustrating information processing based on a scheduling message received by a terminal from a UTRAN according to one embodiment of the present invention.

Detailed Description

Reference will now be made in detail to the preferred embodiments of the present invention, examples of which are illustrated in the accompanying drawings. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts.

The invention may be implemented in a mobile communication system such as UMTS (universal mobile telecommunications system) developed by 3GPP (third generation partnership project). However, the present invention may also be applied to communication systems operating with other specifications. Further, the point-to-multipoint service referred to herein may be a multimedia broadcast/multicast service (MBMS) or other service type. In addition, the terminal referred to herein may be a User Equipment (UE) or other type of terminal.

Fig. 6 is a diagram illustrating a transmission/reception point-to-multipoint service according to one embodiment of the present invention. Thus, fig. 6 illustrates transmission/reception of a point-to-multipoint multimedia service in which a scheduling message and MBMS data are transmitted via a physical channel such as an SCCPCH.

Referring to fig. 6, UTRMT transmits a scheduling message every scheduling period. The scheduling message may include data transmission information including a transmission start time point and a transmission segment of MBMS data transmitted during one scheduling period. The data transmission information may further include a message indicating that there is no data to be transmitted during a corresponding scheduling period, and/or reception reservation (reservation) information. In case there is no data to be transmitted or to be continuously transmitted for several scheduling periods (e.g., reception reservation sections) for a specific MBMS, the UTRAN transmits reception reservation information via a scheduling message transmitted for a section having no data to be transmitted. The reception reservation information may be included in the scheduling message. Alternatively, the reception reservation information may be transmitted by other methods.

The operations of the UTRAN and the UE with respect to the first to sixth scheduling messages as shown in fig. 6 are described as follows.

The UTRAN provides notification of transmission information related to data transmitted between the first scheduling message and the second scheduling message to the UE via the first scheduling message. The UE receives a scheduling message at each scheduling period. After receiving the first scheduling message, the UE receives data transmitted between the first and second scheduling messages according to transmission information related to the data transmitted between the first and second scheduling messages.

The UTRAN transmits reception reservation information, which is included in the second scheduling message. In case there is no data to be transmitted between the second scheduling message and the fifth scheduling message for the corresponding MBMS, the UTRAN informs the UEs that the reception of the third and fourth scheduling messages is reserved using the reception reservation information included in the second scheduling message, as shown in fig. 6. For example, the value of the scheduling message reception reservation segment included in the reception reservation information may be set to "2" to inform the UE to reserve the reception of two scheduling messages transmitted after the transmission of the second scheduling message.

Further, after receiving the second scheduling message, the UE obtains reception reservation information included in the corresponding message and reserves reception of the scheduling message before the fifth scheduling message is transmitted. Thus, the UE receives the second scheduling message, but does not receive the third and fourth scheduling messages.

If the UE fails to receive the second scheduling message, the UTRAN may transmit reception reservation information via a third scheduling message. In this case, the reception reservation information included in the third scheduling message informs the UE that the reception of the fourth scheduling message is reserved. For example, the value of the scheduling message reception reservation segment included in the reception reservation information may be set to "1" to command the UE to reserve reception of one scheduling message transmitted after receiving the third scheduling message. Further, after receiving the third scheduling message, the UE obtains reception reservation information included in the corresponding message and reserves reception of the scheduling message before the fifth scheduling message is transmitted. Therefore, the UE receives the third scheduling message but does not receive the fourth scheduling message.

The UTRAN transmits the fourth scheduling message when the UE fails to receive the second and third scheduling messages. The fourth scheduling message provides notification that: there is no data to be transmitted between the fourth and fifth scheduling messages for the specific MBMS. Further, having received the fourth scheduling message, the UE may recognize that there is no data to transmit. Then, the UE may not accept a channel through which the MBMS data is transmitted before the fifth scheduling message is transmitted.

The UTRAN provides notification of transmission information related to data transmitted between the fifth scheduling message and the sixth scheduling message to the UE via the fifth scheduling message. The transmission information may include a transmission start point and a length of a transmission segment of the data. The UE receives the fifth scheduling message and then receives data transmitted between the fifth scheduling message and the sixth scheduling message according to transmission information related to data included in the corresponding message.

Referring to fig. 7, a UE attempting to receive a specific MBMS acquires configuration information related to a point-to-multipoint radio bearer for the specific MBMS. The UE also receives scheduling period information, which is a transmission period of a scheduling message for supporting data transmission of the specific MBMS, from the UTRAN (S71). The UE configures a point-to-multipoint radio bearer according to the obtained radio bearer configuration information (S72). Once the point-to-multipoint radio bearer is configured, the protocol layers and channel characteristics required to provide the MBMS are defined, and specific parameters and operation methods are established, respectively.

The UE receives a scheduling message transmitted from the UTRAN via a specific physical channel using the obtained scheduling period information (S73). After confirming the contents of the received scheduling message (S74), the UE operates as follows according to the contents of the scheduling message.

First, in case that the content included in the scheduling message corresponds to data transmission information, e.g., information indicating when data is to be transmitted, such as a data transmission start point and a data transmission segment length, the UE discontinuously accepts a physical channel in accordance with the data transmission information in order to receive the data (S74). The UE then waits for transmission of a scheduling message in the next scheduling period.

Alternatively, if the content included in the scheduling message corresponds to the reception reservation information, the UE reserves reception of the scheduling message during a time period defined by the reception reservation information. Alternatively, the UE reserves reception of the scheduling message for a set number of scheduling messages as commanded by the reception reservation information (S75). Thus, the UE does not accept the physical channel during the time period or for a set number of scheduling messages. Instead, the UE waits for a scheduling message transmitted after the time period or a set number of scheduling messages.

Also, in the alternative, in case that the content included in the scheduling message corresponds to information indicating that there is no data transmission during the corresponding scheduling period, the UE does not accept the physical channel during the corresponding scheduling period (S76). Instead, the UE waits for transmission of a scheduling message during the next scheduling period.

Again, in the alternative, if the content included in the scheduling message corresponds to information indicating that the radio bearer for the MBMS is released, the UE releases the radio bearer (S77) and terminates the specific MBMS reception procedure.

The physical channel carrying the scheduling message may preferably be the same as the physical channel carrying the MBMS data. The physical channel may be, for example, an SCCPCH. The MBMS data may preferably be transmitted via a logical channel MTCH mapped to the SCCPCH. The scheduling message may preferably be transmitted via a logical channel other than the MTCH and mapped to the SCCPCH.

In one embodiment, a method of controlling a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system includes receiving the point-to-multipoint service from a network on a physical channel. The method also includes receiving a first scheduling indicator related to a plurality of scheduling periods in which there is no transmission related to the point-to-multipoint service, wherein each scheduling period is related to one scheduling indicator. The method further comprises receiving the point-to-multipoint service via a physical channel after said plurality of scheduling periods where there is no transmission. The point-to-multipoint service and the first scheduling indicator are received on the same physical channel.

The same physical channel may include a common physical channel. The common physical channel may include a SCCPCH (secondary common physical channel). The point-to-multipoint service, the first scheduling indicator and the second scheduling indicator may be received on different logical channels. The first scheduling indicator and the second scheduling indicator may be received on the same logical channel. The point-to-multipoint service may be received on an MTCH (MBMS traffic channel). Alternatively, the point-to-multipoint service is received on different types of logical channels. The network may be a UTMS terrestrial radio network (UTRAN).

In another embodiment, a method in a network for controlling a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system, the method comprising: the method includes transmitting a point-to-multipoint service on a physical channel and determining a plurality of scheduling periods in which there is no transmission related to the point-to-multipoint service. The method also includes transmitting a first scheduling indicator related to a plurality of scheduling periods in which there is no transmission, wherein each scheduling period is related to one scheduling indicator. The method also includes transmitting the physical channel after the plurality of scheduling periods in which there is no transmission. The method further comprises transmitting the point-to-multipoint service via a physical channel after said plurality of scheduling periods in which there is no transmission. The point-to-multipoint service and the first scheduling indicator are transmitted on the same physical channel. The method may further comprise transmitting a second scheduling indicator after said plurality of scheduling periods in which there is no transmission.

Although the present invention can be applied to an asynchronous wireless mobile communication system such as that being standardized by 3GPP (third generation partnership project), the present invention can also be applied to other mobile communication systems providing a point-to-multipoint service.

The present invention allows a User Equipment (UE) that discontinuously receives data related to a point-to-multipoint service to efficiently utilize resources, such as battery power.

It will be apparent to those skilled in the art that various modifications and variations can be made in the present invention without departing from the spirit or scope of the invention. Thus, it is intended that the present invention cover the modifications and variations of this invention provided they come within the scope of the appended claims and their equivalents.

Industrial applicability

The present invention can be applied to a mobile communication system providing a point-to-multipoint service, such as an asynchronous wireless mobile communication system, which is being standardized by 3GPP (third generation partnership project), and the like.

Claims

1. A method of controlling a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system, the method comprising:

receiving a point-to-multipoint service from a network on a physical channel;

2. The method of claim 1, further comprising: receiving a second scheduling indicator after the plurality of scheduling periods where there is no transmission.

3. The method of claim 2, further comprising: receiving the point-to-multipoint service over the physical channel in response to the second scheduling indicator.

4. The method of claim 1, wherein the same physical channel comprises a common physical channel.

5. The method according to claim 4, wherein the common physical channel comprises a SCCPCH (secondary common physical channel).

6. The method of claim 3, wherein a logical channel used to receive the point-to-multipoint service is different from a logical channel used to receive the first scheduling indicator and the second scheduling indicator.

7. The method of claim 6, wherein the first scheduling indicator and the second scheduling indicator are received on the same logical channel.

8. The method of claim 7, wherein the point-to-multipoint service is received on an MTCH (MBMS traffic channel).

9. The method of claim 7, wherein the point-to-multipoint service is received on different types of logical channels.

10. The method of claim 1, wherein the network is a UTMS terrestrial radio network (UTRAN).

11. A method in a network for controlling a User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system, the method comprising:

transmitting the point-to-multipoint service on a physical channel;

12. The method of claim 11, further comprising: transmitting a second scheduling indicator after the plurality of scheduling periods where there is no transmission.

13. The method of claim 11, wherein the same physical channel comprises a common physical channel.

14. The method of claim 11, wherein the common physical channel comprises SCCPCH (secondary common physical channel).

15. The method of claim 11, wherein a logical channel used to receive the point-to-multipoint service is different from a logical channel used to receive the first scheduling indicator and the second scheduling indicator.

16. The method of claim 15, wherein the first scheduling indicator and the second scheduling indicator are received on a same logical channel.

17. The method of claim 16, wherein the point-to-multipoint service is received on an MTCH (MBMS traffic channel).

18. The method of claim 17, wherein the point-to-multipoint service is received on different types of logical channels.

19. The method of claim 11, wherein the network is a UTMS terrestrial radio network (UTRAN).

20. A User Equipment (UE) capable of receiving a point-to-multipoint service in a wireless communication system, the UE comprising:

21. The user equipment of claim 20, further comprising: means for receiving a second scheduling indicator after the plurality of scheduling periods in which there is no transmission.

22. The user equipment of claim 21, further comprising: means for receiving the point-to-multipoint service via the physical channel in response to the second scheduling indicator.