LEE YOUNG DAE (KR)
JUNG MYUNG CHEUL (KR)
CHUN SUNG DUCK (KR)
LEE YOUNG DAE (KR)
JUNG MYUNG CHEUL (KR)
WO2004100447A1 | 2004-11-18 | |||
WO2003015439A1 | 2003-02-20 |
US20040087320A1 | 2004-05-06 | |||
US6256509B1 | 2001-07-03 | |||
EP1353523A1 | 2003-10-15 |
1. | A method of providing a pointtomultipoint service to at least one mobile communication terminal in a mobile communications system, the method comprising: the at least one mobile communications terminal storing a terminal identity and at least one pointtomultipoint service identity, the at least one pointtomultipoint service identity related to a service the terminal is to receive; a network transmitting a frame of control information to the at least one mobile communications terminal via a downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a pointtomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided; the network transmitting a frame of data to the at least one mobile communications terminal via a downlink shared data channel, the frame of the data corresponding to the frame of control information; the mobile terminal receiving the frame of control information and comparing the stored terminal identity and the stored pointtomultipoint service identity to the at least one of a mobile terminal identifier and a pointtomultipoint service identifier in the control information; and the at least one mobile communications terminal receiving the frame of data if at least one of the stored terminal identity matches the terminal identifier in the control information and the stored pointtomultipoint service identity matches the pointto multipoint service identifier in the control information. |
2. | The method of claim 1, wherein the downlink shared control channel is a downlink high speedshared control channel (HSSCCH). |
3. | The method of claim 1 , wherein the downlink shared data channel is a high¬ speed physical downlink shared channel (HSPDSCH). |
4. | The method of claim 1, wherein the frame of data is one of mobile communications terminal dedicated data and multicast data. |
5. | The method of claim 1, wherein the pointtomultipoint service identifier corresponds to a specific pointtomultipoint service. |
6. | The method of claim 1, wherein the pointtomultipoint service identifier corresponds to a specific session of a specific pointtomultipoint service. |
7. | The method of claim 1, wherein the pointtomultipoint service identifier corresponds to a plurality of mobile communication terminals that are to receive a specific pointtomultipoint service. |
8. | The method of claim 1, further comprising: the at least one mobile communications terminal decoding the frame of data; and the at least one mobile communications terminal transmitting reception status information to the network, the reception status information comprising an indication of one of the reception of the frame of data without errors and the reception of the frame of data with errors. |
9. | The method of claim 8, wherein the reception status information further comprises downlink channel quality information. |
10. | The method of claim 8, wherein the reception status information is transmitted via a subframe of a high speeddedicated physical control channel (HS DPCCH) that is mapped to a subframe of a high speed physical downlink shared channel (HSPDSCH). |
11. | The method of claim 8, further comprising: the at least one mobile communications terminal transmitting reception status information comprising an indication of reception of the frame of data with errors; the network retransmitting the frame of control information to the at least one mobile communications terminal via the downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a pointto multipoint service identifier, the pointtomultipoint service identifier related to a service being provided; the network retransmitting a frame of data to the at least one mobile communications terminal via the downlink shared data channel, the frame of data corresponding to the frame of control information; the mobile terminal receiving the retransmitted frame of control data and comparing the stored terminal identity and the stored pointtomultipoint service identity to the at least one of a mobile terminal identifier and a pointtomultipoint service identifier in the control information; and the at least one mobile communications terminal receiving the retransmitted frame of data if at least one of the stored terminal identity matches the terminal identifier in the control information and the stored pointtomultipoint service identity matches the pointtomultipoint service identifier in the control information. |
12. | The method of claim 11, wherein the control information comprises a point tomultipoint service identifier if a number of mobile communication terminals transmitting reception status information comprising an indication of reception of the frame of data with errors exceeds a threshold and the control information comprises a mobile terminal identifier of each terminal that transmitted reception status information comprising an indication of reception of the frame of data with errors if the number of mobile communication terminals transmitting reception status information comprising an indication of reception of the frame of data with errors does not exceed the threshold. |
13. | The method of claim 1, further comprising the at least one mobile communication terminal informing the network during a connection procedure whether it can receive the downlink shared control channel and the downlink shared data channel. |
14. | The method of claim 1, further comprising the network informing the at least one mobile communication terminal that the frame of control information will be transmitted via the downlink shared control channel and the frame of data will be transmitted via the downlink shared data channel. |
15. | The method of claim 1, wherein the pointtomultipoint service is a multimedia broadcast or multicast service (MBMS). |
16. | A method of providing a pointtomultipoint service to at least one mobile communication terminal in a mobile communications system, the method comprising: (UE claim) storing a terminal identity and at least one pointtomultipoint service identity, the at least one pointtomultipoint service identity related to a service to be received; receiving a frame of control information via a downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a point tomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided; comparing the stored terminal identity and the stored pointtomultipoint service identity to the at least one of a mobile terminal identifier and a pointtomultipoint service identifier in the control information; and receiving a frame of data via a downlink shared data channel if at least one of the stored terminal identity matches the terminal identifier in the control information and the stored pointtomultipoint service identity matches the pointtomultipoint service identifier in the control information, the frame of the data corresponding to the frame of control information. |
17. | The method of claim 16, wherein the downlink shared control channel is a downlink high speedshared control channel (HSSCCH). |
18. | The method of claim 16, wherein the downlink shared data channel is a highspeed physical downlink shared channel (HSPDSCH). |
19. | The method of claim 16, wherein the frame of data is one of mobile communications terminal dedicated data and multicast data. |
20. | The method of claim 16, further comprising: decoding the frame of data; and transmitting reception status information to the network, the reception status information comprising an indication of one of the reception of the frame of data without errors and the reception of the frame of data with errors. |
21. | The method of claim 20, wherein the reception status information further comprises downlink channel quality information. |
22. | The method of claim 20, wherein the reception status information is transmitted via a subframe of a high speeddedicated physical control channel (HS DPCCH) that is mapped to a subframe of a high speed physical downlink shared channel (HSPDSCH). |
23. | The method of claim 20, further comprising: transmitting reception status information comprising an indication of reception of the frame of data with errors; receiving a retransmitted frame of control information via the downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a pointtomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided; comparing the stored terminal identity and the stored pointtomultipoint service identity to the at least one of a mobile terminal identifier and a pointtomultipoint service identifier in the control information; and receiving a retransmitted frame of data via the downlink shared data channel if at least one of the stored terminal identity matches the terminal identifier in the control information and the stored pointtomultipoint service identity matches the pointto multipoint service identifier in the control information. |
24. | The method of claim 16, further comprising informing the network during a connection procedure whether the downlink shared control channel and the downlink shared data channel may be received. |
25. | The method of claim 16, further comprising receiving an indication that the frame of control information will be transmitted via the downlink shared control channel and the frame of data will be transmitted via the downlink shared data channel. |
26. | The method of claim 16, wherein the pointtomultipoint service is a multimedia broadcast or multicast service (MBMS). |
27. | A method of providing a pointtomultipoint service to at least one mobile communication terminal in a mobile communications system, the method comprising: transmitting a frame of control information to the at least one mobile communications terminal via a downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a pointtomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided; and transmitting a frame of data to the at least one mobile communications terminal via a downlink shared data channel, the frame of the data corresponding to the frame of control information. |
28. | The method of claim 27, wherein the downlink shared control channel is a downlink high speedshared control channel (HSSCCH). |
29. | The method of claim 27, wherein the downlink shared data channel is a highspeed physical downlink shared channel (HSPDSCH). |
30. | The method of claim 27, wherein the frame of data is one of mobile communications terminal dedicated data and multicast data. |
31. | The method of claim 27, further comprising receiving reception status information from the at least one mobile communications terminal, the reception status information comprising an indication of one of the reception of the frame of data without errors and the reception of the frame of data with errors. |
32. | The method of claim 31 , further comprising receiving downlink channel quality information. |
33. | The method of claim 31 , wherein the reception status information is transmitted via a subframe of a high speeddedicated physical control channel (HS DPCCH) that is mapped to a subframe of a high speed physical downlink shared channel (HSPDSCH). |
34. | The method of claim 31 , further comprising: receiving reception status information from the at least one mobile communications terminal, the reception status information comprising an indication of reception of the frame of data with errors; retransmitting the frame of control information to the at least one mobile communications terminal via the downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a pointtomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided; and retransmitting the frame of data to the at least one mobile communications terminal via the downlink shared data channel, the frame of data corresponding to the frame of control information; . |
35. | The method of claim 34, wherein the control information comprises a point tomultipoint service identifier if a number of mobile communication terminals transmitting reception status information comprising an indication of reception of the frame of data with errors exceeds a threshold and the control information comprises a mobile terminal identifier of each terminal that transmitted reception status information comprising an indication of reception of the frame of data with errors if the number of mobile communication terminals transmitting reception status information comprising an indication of reception of the frame of data with errors does not exceed the threshold. |
36. | The method of claim 27, further comprising receiving an indication from the at least one mobile communication terminal whether the at least one mobile communication terminal can receive the downlink shared control channel and the downlink shared data channel, the indication received during a connection procedure. |
37. | The method of claim 27, further comprising informing the at least one mobile communication terminal that the frame of control information will be transmitted via the downlink shared control channel and frame of data will be transmitted via the downlink shared data channel. |
38. | The method of claim 27, wherein the pointtomultipoint service is a multimedia broadcast or multicast service (MBMS). |
39. | A mobile communication terminal for receiving a pointtomultipoint service in a mobile communications system, the mobile communication terminal comprising: an antenna adapted to receive RF signals containing messages comprising a frame of control information and a frame of data; an RF module adapted to process the RF signals received by the antenna; a keypad adapted for inputting information from a user; a storage unit adapted to store a terminal identity and at least one pointto multipoint service identity, the at least one pointtomultipoint service identity related to a service to be received; a display adapted to convey information to the user; and a processing unit adapted to: process the frame of control information received via a downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a pointtomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided, compare the stored terminal identity and the stored pointtomultipoint service identity to the at least one of a mobile terminal identifier and a pointtomultipoint service identifier in the control information, and process the frame of data received via a downlink shared data channel if at least one of the stored terminal identity matches the teπninal identifier in the control information and the stored pointtomultipoint service identity matches the pointtomultipoint service identifier in the control information, the frame of the data corresponding to the frame of control information. |
40. | The mobile communication terminal of claim 39, wherein the downlink shared control channel is a downlink high speedshared control channel (HSSCCH). |
41. | The mobile communication terminal of claim 39, wherein the downlink shared data channel is a highspeed physical downlink shared channel (HSPDSCH). |
42. | The mobile communication terminal of claim 39, wherein the frame of data is one of mobile communications terminal dedicated data and multicast data. |
43. | The mobile communication terminal of claim 39, wherein the processing unit is further adapted to decode the frame of data and transmit reception status information to the network, the reception status information comprising an indication of one of the reception of the frame of data without errors and the reception of the frame of data with errors. |
44. | The mobile communication terminal of claim 43, wherein the processing unit is further adapted to generate the reception status information comprising downlink channel quality information. |
45. | The mobile communication terminal of claim 43, wherein the processing unit is further adapted to transmit the reception status information via a subframe of a high speeddedicated physical control channel (HSDPCCH) that is mapped to a subframe of a high speed physical downlink shared channel (HSPDSCH). |
46. | The mobile communication terminal of claim 43, wherein the processing unit is further adapted to: transmit reception status information comprising an indication of reception of the frame of data with errors; process a retransmitted frame of control information received via the downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a pointtomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided; compare the stored terminal identity and the stored pointtomultipoint service identity to the at least one of a mobile terminal identifier and a pointtomultipoint service identifier in the control information; and process a retransmitted frame of data received via the downlink shared data channel if at least one of the stored terminal identity matches the terminal identifier in the control information and the stored pointtomultipoint service identity matches the pointto multipoint service identifier in the control information. |
47. | The mobile communication terminal of claim 39, wherein the processing unit is further adapted to inform the network during a connection procedure whether the downlink shared control channel and the downlink shared data channel may be received. |
48. | The mobile communication terminal of claim 39, wherein the processing unit is further adapted to process an indication that the frame of control information will be transmitted via the downlink shared control channel and the frame of data will be transmitted via the downlink shared data channel. |
49. | The mobile communication terminal of claim 39, wherein the pointto multipoint service is a multimedia broadcast or multicast service (MBMS). |
50. | A network for providing a pointtomultipoint service to at least one mobile communication terminal in a mobile communications system, the network comprising: a transmitter adapted to transmit signals containing a frame of control information and a frame of data to the at least one mobile communication terminal; a receiver adapted to receive signals comprising reception status information and downlink channel quality information from the at least one mobile communications terminal; and a controller adapted to: transmit the frame of control information via a downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a point tomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided; and transmit the frame of data via a downlink shared data channel, the frame of the data corresponding to the frame of control information. |
51. | The network of claim 50, wherein the downlink shared control channel is a downlink high speedshared control channel (HSSCCH). |
52. | The network of claim 50, wherein the downlink shared data channel is a highspeed physical downlink shared channel (HSPDSCH). |
53. | The network of claim 50, wherein the controller is further adapted to generate the frame of data comprising one of mobile communications terminal dedicated data and multicast data. |
54. | The network of claim 50, wherein the controller is further adapted to process the reception status information, the reception status information comprising an indication of one of the reception of the frame of data without errors and the reception of the frame of data with errors. |
55. | The network of claim 54, wherein the controller is further adapted to process the downlink channel quality information. |
56. | The network of claim 54, wherein the controller is further adapted to process the reception status information received via a subframe of a high speeddedicated physical control channel (HSDPCCH) that is mapped to a subframe of a high speed physical downlink shared channel (HSPDSCH). |
57. | The network of claim 54, wherein the controller is further adapted to: process reception status information comprising an indication of reception of the frame of data with errors; retransmit the frame of control information to the at least one mobile communications terminal via the downlink shared control channel, the control information comprising at least one of a mobile terminal identifier and a pointtomultipoint service identifier, the pointtomultipoint service identifier related to a service being provided; and retransmit a frame of data to the at least one mobile communications terminal via the downlink shared data channel, the frame of data corresponding to the frame of control information; . |
58. | The network of claim 57, wherein the controller is further adapted to generate the control information comprising a pointtomultipoint service identifier if a number of mobile communication terminals transmitting reception status information comprising an indication of reception of the frame of data with errors exceeds a threshold and to generate the control information comprising a mobile terminal identifier of each terminal that transmitted reception status information comprising an indication of reception of the frame of data with errors if the number of mobile communication terminals transmitting reception status information comprising an indication of reception of the frame of data with errors does not exceed the threshold. |
59. | The network of claim 50, wherein the controller is further adapted to process an indication from the at least one mobile communication terminal whether the at least one mobile communication terminal can receive the downlink shared control channel and the downlink shared data channel, the indication received during a connection procedure. |
60. | The network of claim 50, wherein the controller is further adapted to inform the at least one mobile communication terminal that the frame of control information will be transmitted via the downlink shared control channel and frame of data will be transmitted via the downlink shared data channel. |
61. | The network of claim 50, wherein the pointtomultipoint service is a multimedia broadcast or multicast service (MBMS). |
MBMS
TECHNICAL FIELD
The present invention relates to a method and apparatus for transmitting and
receiving a multimedia broadcast/multicast service (MBMS), and more particularly, to
an apparatus and method for transmitting and receiving an MBMS using Automatic
Repeat Request (ARC) and Hybrid Automatic Repeat Request (HARQ). Although the
present invention is suitable for a wide scope of applications, it is particularly suitable
for providing a multicast transmission using adaptive modulation and channel coding
and Hybrid ARQ to a wireless mobile user equipment to enable the user equipment to
receive high-speed multicast data.
BACKGROUND ART
FIG. 1 illustrates a block diagram of a network structure of UMTS (Universal
Mobile Telecommunications System). A UMTS includes user equipment (hereinafter
abbreviated UE), a UMTS terrestrial radio access network (hereinafter abbreviated
UTRAN), and a core network (hereinafter abbreviated CN).
The UTRAN includes at least one radio network sub-system (hereinafter
abbreviated RNS). The RNS includes one radio network controller (hereinafter
abbreviated RNC) and at least one base station (hereinafter called Node B) managed by
the RNC. At least one or more cells exist in one Node B.
FIG. 2 illustrates an architectural diagram of a radio interface protocol between
one UE and a UTRAN. A radio interface protocol vertically includes a physical layer, a
data link layer, and a network layer and horizontally includes a user plane for data
information transfer and a control plane for signaling transfer. The protocol layers in
FIG. 2 can be divided into Ll (first layer), L2 (second layer) and L3 (third layer) based
on three lower layers of the open system interconnection (OSI) standard model widely
known in the communications systems.
The physical layer (hereinafter named PHY) offers information transfer
services to an upper layer using physical channels. The physical layer is connected to a
medium access control (hereinafter abbreviated MAC) layer above the physical layer
via transport channels. Data are transferred between the MAC layer and the PHY layer
via a transport channel. Data are transferred between different physical layers, and more
specifically, between one physical layer of a transmitting side and the other physical
layer of a receiving side via physical channels.
The MAC layer of the second layer offers services to a radio link control layer
above the MAC layer via logical channels. The radio link control (hereinafter
abbreviated RLC) layer of the second layer supports reliable data transfer and performs
segmentation and concatenation of RLC service data units (hereinafter abbreviated
SDU) sent down from an upper layer.
A radio resource control (hereinafter abbreviated RRC) layer located on a
lowest part of the third layer is defined in the control plane only and is associated with
configuration, reconfiguration and release of radio bearers (hereinafter abbreviated RB)
for controlling the logical, transport and physical channels. A RB is a service offered to
the second layer for the data transfer between the UE and the UTRAN. The
configuration of a RB is a process of regulating characteristics of protocol layers and
channels necessary for offering a specific service and a process of setting their specific
parameters and operational methods, respectively.
A multimedia broadcast/multicast service (hereinafter abbreviated MBMS)
offers a streaming or background service to a plurality of UEs using a downlink
dedicated MBMS bearer service. One MBMS includes at least one session, and MBMS
data are transmitted to a plurality of the UEs via the MBMS bearer service only during
an ongoing session.
A UTRAN offers the MBMS bearer service to a UE via a radio bearer. The
types of RB used by the UTRAN include a point-to-point radio bearer and a point-to-
multipoint radio bearer. A point-to-point radio bearer is a bi-directional radio bearer and
includes 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). A point-to-
multipoint radio bearer is a unidirectional downlink radio bearer.
FIG. 3 illustrates channel mapping for MBMS. A point-to-multipoint radio
bearer includes a logical channel MTCH (MBMS traffic channel), a transport channel
FACH (forward access channel) and a physical channel SCCPCH. The logical channel
MTCH is configured for each MBMS offered to one cell and is used in transmitting
user-plane data of a specific MBMS to a plurality of UEs.
A logical channel MCCH (MBMS control channel) is a point-to-multipoint
downlink channel used in transmitting control information associated with the MBMS.
The logical channel MCCH is mapped to the transport channel FACH (forward access
channel), while the transport channel FACH is mapped to the physical channel
SCCPCH (secondary common control physical channel). One MCCH exists within one
cell.
The UTRAN offering the MBMS transmits MCCH information to a plurality
of UEs via the MCCH. The MCCH information includes a notification message
associated with the MBMS, for example, an RRC message associated with the MBMS.
The MCCH information may include a message that indicates MBMS information, a
message that notifies point-to-multipoint radio bearer information or access information
indicating that an RRC connection is requested for a specific MBMS.
FIG. 4 illustrates a transmission system of MCCH information. The MCCH
information is periodically transmitted according to a modification period and a
repetition period.
The MCCH information is divided into critical information and non-critical
information. The non-critical information can be freely modified each modification
period or each repetition period. The modification of the critical information can be
made only each modification period. Specifically, the critical information is repeated
one time each repetition period and the transmission of the modified critical information
is possible at a start point of the modification period only.
The UTRAN periodically transmits a physical channel MICH (MBMS
notification indicator channel) to indicate whether the MCCH information is updated
during the modification period. Therefore, a UE attempting to receive only one specific
MBMS does not receive the MCCH or MTCH until a session of the service begins, but
receives MICH (MBMS notification indicator channel) periodically. For reference, the
update of the MCCH information means a generation, addition, modification or removal
of a specific item of the MCCH information.
FIG. 5 illustrates a flowchart of a process for executing an MBMS according to
the related art. Once a session of a specific MBMS begins (S51), a UTRAN transmits
an NI (notification indicator) to a UE attempting to receive a specific MBMS (S52).
The NI indicates that an MCCH channel should be received. The UE, having received
the NI via an MICH, receives an MCCH for 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
(S53). After completion of configuring the point-to-multipoint radio bearer, the UE
keeps receiving a physical channel SCCPCH, to which an MTCH is mapped, in order to
acquire data of the specific MBMS transmitted via the MTCH (S54). If a session ends
(S55), the configured point-to-multipoint radio bearer is released (S56).
FIG. 6 illustrates a method of transmitting MBMS data discontinuously via
MTCH. A UTRAN periodically transmits a scheduling message to a UE via an
SCCPCH (SCCPH carrying MTCH) to which an MTCH is mapped. The scheduling
message indicates a transmission start point and transmission section of MBMS data
transmitted during one scheduling period. The UTRAN should previously inform the
UE of a transmission period (scheduling period) of scheduling information.
The UE acquires the scheduling period from the UTRAN, receives the
scheduling message periodically according to the acquired scheduling period, and then
receives the SCCPCH (SCCPH carrying MTCH) to which the MTCH is mapped. The
SCCPCH is received discontinuously and periodically using the received scheduling
message. Specifically, the UE, using the scheduling message, receives the SCCPCH
carrying the MTCH during a timing section for which the data is transmitted but does
not receive the SCCPCH carrying the MTCH during a time section for which the data is
not transmitted. The method is advantageous in that the UE can efficiently receive the
data to reduce its battery consumption.
An HS-DSCH transmission of transmitting high-speed data in downlink to one
UE is explained as follows.
An HS-DSCH has a 2ms transmission time interval (hereinafter abbreviated
TTI) (3 slot) and supports various modulation code sets (hereinafter abbreviated MCSs)
for a high data rate. By selecting an MCS most suitable for a channel status, an optimal
throughput is provided. HARQ is adopted to enable a reliable transmission. HARQ
involves combining ARQ and channel coding.
FIG. 7 illustrates an HS-DSCH protocol stack according to the related art. A
data unit delivered from an RLC layer of a serving radio network controller (hereinafter
abbreviated SRNC) is delivered to an MAC-d entity managing a dedicated channel via a
logical channel DTCH (dedicated traffic channel) or DCCH (dedicated control channel).
The data unit is then passed through a MAC-c/sh/m of a controlling radio network
controller (hereinafter abbreviated CRNC) to deliver the corresponding data to a MAC-
hs of a Node B. The MAC-d is an entity that manages the dedicated channel. The
MAC-c/sh/m is an entity that manages a common channel. The MAC-hs is a MAC
entity that manages the HS-DSCH.
A physical channel HS-PDSCH is used for delivering the HS-DSCH, which is
a transport channel. A spreading factor of the HS-PDSCH is fixed at 16 and the HS-
PDSCH corresponds to one channelization code selected from a channelization code set
prepared for a HS-DSCH data transmission. When performing a multi-code
transmission for one UE, a plurality of channelization codes are assigned during the
same HS-PDSCH sub-frame.
FIG. 8 illustrates a HS-DSCH sub-frame and slot according to the related art.
A HS-PDSCH transfers QPSK (Quadrature Phase Shift Keying) or 16-QAM
(Quadrature Amplitude Modulation) modulation symbols. In FIG. 8, "M" designates a
bit number per modulation symbol. For QPSK, "M" is equal to 2 (M=2) and for 16-
QAM, "M" is equal to 4 (M=4).
FIG. 9 illustrates a channel configuration according to the related art. A
transmission of HS-DSCH control information is needed to transfer user data via an HS-
DSCH. The information is transmitted via a downlink high-speed shared control
channel (HS-SCCH) and a downlink high speed dedicated physical control channel
(HS-DPCCH). A DPCH (dedicated physical channel) is a bi-directional physical
channel to which a transport channel DCH is mapped. The DPCH is used to deliver
dedicated data of a UE and Ll control information dedicated to a UE, such as a power
control signal necessary for closed loop power control.
An F-DPCH (fractional dedicated physical channel) is a downlink channel for
transferring several DPCHs using one channelization code. One F-DPCH does not
transfer UE dedicated data for several UEs but rather is used to transfer UE-dedicated
Ll control information for several UEs, such as the power control signal necessary for
the closed loop power control. If the downlink F-DPCH exists, the downlink F-DPCH
interfaces with an uplink DPCH. A plurality of UEs share the F-DPCH for use via one
channel code. Each of the UEs is provided with an uplink DPCH.
FIG. 10 is a structural diagram of a sub-frame of HS-PDSCH according to the
related art. A downlink HS-SCCH is a downlink physical channel transferred with a
spreading factor set to 128 such that the data rate is 60 kbps. Information transferred
over the downlink HS-SCCH can be classified into transport format and resource related
information (hereinafter abbreviated TFRI) and HARQ related information. UE identity
(H-RNTI) information, which indicates to which user the corresponding information
belongs, is masked for transfer.
FIG. 11 is a flowchart of an HS-SCCH coding method according to the related
art. HS-SCCH information for HS-SCCH coding is illustrated in Table TBD. HARQ
and UE ID information is illustrated in Table II.
Table I
Channelization-code-set information (7 bits): xccs 1, xccs 2,
xccs 7
Modulation scheme information (1 bit): xms 1
Transport-block size information (6 bits): xtbs 1, xtbs 2, ... , xtbs 6
Table II
Hybrid- ARQ process information (3 bits): xhaρ l, xhap 2 , xhap 3
Redundancy and constellation version (3 bits): xrv 1, xrv 2, xrv 3
New data indicator (1 bit): xnd 1
UE identity (16 bits): xue 1, xue 2 , ... , xue 16
FIG. 12 is a structural diagram of a frame of uplink HS-DPCCH according to
the related art. An uplink HS-DPCCH transfers uplink feedback signaling associated
with a downlink HS-DSCH data transmission.
The HS-DPCCH is a channel dedicated to a specific UE and interfaces with an
uplink DPCH (dedicated physical channel) and a downlink DPCH (dedicated physical
channel). The feedback signaling includes ACK (acknowledgement) or NACK
(negative acknowledgement) information for HARQ and a CQI (channel quality
indicator). A frame of the HS-DPCCH includes five sub-frames, each of which has a
length of 2ms. Each of the sub-frames includes three slots.
The ACK/NACK information for HARQ is transmitted for a first slot of the
HS-DPCCH sub-frame. The CQI is transmitted for second and third slots of the HS-
DSCH sub-frame.
The HS-DPCCH is always transmitted together with UL PDCCH. The CQI
delivers status information of a downlink radio channel. The status information is
obtained from a measurement of a downlink CPICH (common pilot channel) by a UE.
The ACK/NACK indicates the ACK or NACK information for a user data packet
transmission transmitted over a downlink HS-DSCH by the HARQ mechanism.
However, related art methods provide a maximum data rate for MBMS of only
256 Kbps, which corresponds to a maximum speed of one SCCPCH. Therefore, the
related art methods are unable to provide an MBMS having a data rate greater than 256
Kbps. Furthermore, since an uplink channel for the MBMS is not provided, related art
systems are unable to deliver information (ACK or NACK) in response to the MBMS
transmission.
Therefore, there is a need for an apparatus and method to provide MBMS at a
data rate greater than 256 Kbps and allow ACK/NACK information to be provided in
response to the MBMS transmission. The present invention addresses these and other
needs.
DISCLOSURE OF THE INVENTION
Features and advantages of the invention will be set forth in the description
which follows, and in part will be apparent from the description, or may be learned by
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.
The invention is directed to provide a multimedia broadcast/multicast service
(MBMS) at a data rate greater than 256 Kbps and allow ACK/NACK information to be
provided in response to the MBMS transmission. An object of the present invention is
to provide an apparatus and method for transmitting and receiving an MBMS, by which
adaptive modulation and coding and HARQ can be used in performing a high-speed
multimedia broadcast/multicast service.
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 may 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 receiving an
MBMS by a mobile subscriber station storing a generic mobile subscriber station
identity and at least one multimedia broadcast/multicast service (MBMS) identity, a
method of receiving the multimedia broadcast/multicast service (MBMS) according to
the present invention includes the steps of receiving at least one of the mobile subscriber
station identity and the multicast service identity via a control channel, comparing the
stored mobile subscriber station identity and the stored multicast service identity to the
received mobile subscriber station identity or the multicast service identity, and if at
least one of the stored identities matches at least one of the received identities, receiving
a frame of a data corresponding to a specific frame of the control channel.
Preferably, the control channel is a downlink high speed-shared control
channel (HS-SCCH).
Preferably, the data channel is a high-speed physical downlink shared channel
(HS-PDSCH).
Preferably, the method further includes the steps of decoding the received
frame of the data and transmitting control information including a response signal
(ACK/NACK) according to a result of the decoding step via an uplink control channel.
More preferably, data received via the frame of the data channel are either mobile
subscriber station dedicated data or multicast data. More preferably, the control
information further includes downlink channel quality information.
More preferably, the control information is transmitted via a sub-frame of a
high speed-downlink physical channel (HS-DPCCH).
In another aspect of the present invention, in transmitting a multimedia
broadcast/multicast service (MBMS) to at least one mobile subscriber station, each
storing a generic mobile subscriber station identity and at least one multimedia
broadcast/multicast service (MBMS) identity, a method of transmitting the multimedia
broadcast/multicast service (MBMS) includes the steps of transmitting a multimedia
broadcast/multicast identity via a control channel, transmitting data corresponding to the
multimedia broadcast/multicast identity, receiving control information including
information indicating a success or failure in decoding the data from the at least one
mobile subscriber station, and selecting one of the at least one mobile subscriber
stations to which a retransmission shall be performed.
Preferably, the method further includes the steps of transmitting a multimedia
broadcast/multicast identity to the selected mobile subscriber station via the control
channel and transmitting data corresponding to the multimedia broadcast/multicast
identity.
More preferably, the control channel is a downlink high speed-shared control
channel (HS-SCCH). More preferably, the data is transmitted via a sub-frame of a high
speed-physical downlink shared channel (HS-PDSCH).
More preferably, the control information further includes downlink channel
quality information.
In another aspect of the present invention a network and mobile
communication terminal apparatus is provided that are adapted to implement the
methods of the present invention.
It is to be understood that both the foregoing general description and the
following detailed description of the present invention are exemplary and explanatory
and are intended to provide further explanation of the invention as claimed.
Additional features and advantages of the invention will be set forth in the
description which follows, and in part will be apparent from the description, or may be
learned by practice of the invention. It is to be understood that both the foregoing
general description and the following detailed description of the present invention are
exemplary and explanatory and are intended to provide further explanation of the
invention as claimed.
These and other embodiments will also become readily apparent to those
skilled in the art from the following detailed description of the embodiments having
reference to the attached figures, the invention not being limited to any particular
embodiments disclosed.
BRIEF DESCRIPTION OF THE 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
specification, illustrate embodiments of the invention and together with the description
serve to explain the principles of the invention. Features, elements, and aspects of the
invention that are referenced by the same numerals in different figures represent the
same, equivalent, or similar features, elements, or aspects in accordance with one or
more embodiments.
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. In the drawings:
FIG. 1 is a block diagram of a network structure of a conventional UMTS.
FIG. 2 illustrates a structure of a radio interface protocol between a
conventional UE and UTRAN.
FIG. 3 is a diagram illustrating channel mapping for a conventional MBMS.
FIG. 4 is a diagram illustrating a transmission of MCCH information for a
conventional MBMS data transmission.
FIG. 5 is a flowchart of a process of executing a conventional MBMS.
FIG. 6 is a diagram illustrating a conventional method of transmitting MBMS
data discontinuously via MTCH.
FIG. 7 illustrates a conventional HS-DSCH protocol stack.
FIG. 8 illustrates a conventional HS-DSCH sub-frame and slot.
FIG. 9 illustrates a conventional channel configuration.
FIG. 10 is a structural diagram of a conventional sub-frame of HS-SCCH.
FIG. 11 is a flowchart of a conventional HS-SCCH coding method.
FIG. 12 is a structural diagram of a frame of a conventional uplink HS-DPCCH.
FIG. 13 is a diagram illustrating an example of a data transmission via HS-
SCCH and HS-PDSCH according to one embodiment of the present invention.
FIG. 14 is an exemplary flowchart of an HS-SCCH coding method according
to one embodiment of the present invention.
FIG. 15 is an exemplary flowchart of a UE operation according to HS-SCCH
and HS-PDSCH transmission according to one embodiment of the present invention.
FIG. 16 illustrates an HS-DSCH transmission according to one embodiment of
the present invention.
FIG. 17 is a flowchart of a multicast retransmission method according to one
embodiment of the present invention.
FIG. 18 illustrates a channel for a multicast data transmission according to one
embodiment of the present invention.
FIG. 19 illustrates an HS-DSCH protocol stack according to one embodiment
of the present invention.
FIG. 20 illustrates an MAC PDU of HS-DSCH according to one embodiment
of the present invention.
FIG. 21 illustrates a MAC of a UTRAN according to one embodiment of the
present invention.
FIG. 22 illustrates a MAC of a UE according to one embodiment of the present
invention.
FIG. 23 is a flowchart of an MBMS channel determining process according to
one embodiment of the present invention.
FIG. 24 is a flowchart of an MBMS channel establishing process according to
one embodiment of the present invention.
FIG. 25 is a block diagram of a radio communication apparatus according to
one embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention relates to an apparatus and method for transmitting and
receiving MBMS information. Although the present invention is illustrated with respect
to a mobile communication device, it is contemplated that the present invention may be
utilized anytime it is desired to transmit a service to one or more users.
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.
FIG. 13 is a diagram illustrating an example of a data transmission via HS-
SCCH and HS-PDSCH. The HS-PDSCH (high speed-physical downlink shared
channel) can transmit a UE dedicated data unit for a specific UE or a multicast data unit
for one or more UEs subscribed to a specific multicast service for each sub-frame. The
UE dedicated data unit is a logical channel DTCH or DCCH data unit and the multicast
data unit is a logical channel MTCH, MCCH or MSCH data unit.
If the UE dedicated data unit is transmitted for the HS-PDSCH sub-frame, a
mapped HS-SCCH sub-frame transmits a UE identity allocated to the UE. If the
multicast data unit is transmitted for the HS-PDSCH sub-frame, the mapped HS-SCCH
sub-frame transmits an MBMS identity allocated to the multicast service.
Referring to FIG. 13, an MBMS identity is an identity of a specific MBMS
allocated by a CN or an RRC of a UTRAN. The MBMS identity is an MBMS
transmission identity or an MBMS-Id.
The MBMS identity is an identity allocated by the CN to identify a specific
MBMS. The MBMS transmission identity includes an MBMS identity and an MBMS
session identity.
The MBMS session identity is an identity that identifies a specific session of a
specific MBMS. The MBMS-id is a service identity allocated by the UTRAN and is an
MBMS identity included in a MAC header of an MTCH.
The MBMS identity can be replaced by a UE group identity. The UE group
identity is an identity that identifies a UE group consisting of one or more UEs
attempting to receive the same data.
FIG. 14 illustrates HS-SCCH information for an HS-SCCH coding method.
The TFRI information is listed in Table III. The HARQ information listed in Table IV.
The UE ID information listed in Table V.
Table III
Channelization-code-set information (7 bits): xccs 1, xccs 2, ... ,
xccs 7
Modulation scheme information (1 bit): xms 1
Transport-block size information (6 bits): xtbs 1, xtbs 2, ... , xtbs 6
Table IV
Hybrid- ARQ process information (3 bits): xhap 1, xhap 2, xhap 3
Redundancy and constellation version (3 bits): xrv 1, xrv 2, xrv 3
New data indicator (1 bit): xnd 1
Table V
UE identity (16 bits): xue I, xue 2, ... , xue 16
MBMS identity (16 bits): xme 1, xme 2, ... , xme 16
An MBMS identity or UE identity, as shown in FIG. 14, is encoded in a CRC
(Cyclic Redundancy Check) attachment and masking is according to a type of data to be
transmitted. A UE attempting to receive multicast data via HS-DSCH should be
provided with both the UE identity and the MBMS identity.
FIG. 15 illustrates a flowchart of UE operation according to HS-SCCH and
HS-PDSCH transmission. A UE stores its UE identity. If there is at least one service
that the UE attempts to receive, the UE also stores the MBMS identities corresponding
to the services (S 151). The UE receives an HS-SCCH (S 152) and acquires identity
information from a sub-frame of the received HS-SCCH (Sl 53). The UE checks
whether the acquired identity is identical to the UE or MBMS identity it has stored.
If there is no match, the UE again receives the next HS-SCCH (Sl 52) and re-
acquires identity information from a sub-frame of the received HS-SCCH (S 153). If
there is a match, the UE receives an HS-PDSCH sub-frame mapped to the sub-frame of
the received HS-SCCH (Sl 54). The UE transmits a response signal to indicate the
reception of the HS-PDSCH sub-frame either without errors (ACK) or with errors
(NACK) (S 155).
FIG. 16 illustrates an HS-DSCH transmission according to one embodiment of
the present invention. A multicast transmission via HS-PDSCH according to the present
invention is explained according to FIG. 16.
The HS-PDSCH transmits UE dedicated data for a specific UE or multicast
data for one or more UEs subscribed to a specific multicast service for each sub-frame.
AUE then transmits a signal in response to the data transmissions via a sub-frame of an
HS-DPCCH mapped to the HS-PDSCH sub-frame. Each of the sub-frames delivers a
response signal for the UE dedicated data or for the multicast data according to a type of
the received data. The response signal is ACK or NACK.
Upon decoding the received data, an ACK response is transmitted if the data is
received without error. If an error occurs, an NACK response is transmitted. The sub-
frame of the HS-DPCCH can transmit CQI (channel quality indicator) information
together with the ACK or NACK signal.
FIG. 17 illustrates a flowchart of a multicast retransmission method according
to one embodiment of the present invention. Each of a plurality of UEs (UE#1, UE#2)
attempting to receive a specific MBMS receives an HS-SCCH sub-frame in order to
acquire an MBMS identity (S 171). If the acquired identity is the MBMS corresponds to
a service to which a UE has subscribed, the UE receives a corresponding HS-PDSCH
sub-frame to acquire multicast data (S 172).
A first UE (UE #1) transmits ACK or NACK information for the received
multicast data via HS-DPCCH after receiving the HS-PDSCH sub-frame (S 173). The
first UE (UE #1) can periodically transmit CQI information. As illustrated in FIG. 17,
NACK information is transmitted since errors occur in the received data.
A second UE (UE #2) transmits ACK or NACK information for the received
multicast data via HS-DPCCH after receiving the HS-PDSCH sub-frame (S 174). The
second UE (UE #2) can periodically transmit CQI information. As illustrated in FIG. 17,
NACK information is transmitted since errors occur in the received data.
If a number of UEs exceeding a threshold value transmit NACK, a Node B
retransmits the data to a plurality of UEs using an MBMS identity and then retransmits
the MBMS identity via the HS-SCCH (S175). Each of the plurality of UEs receives the
HS-SCCH sub-frame and acquires the MBMS identity. If the acquired MBMS identity
corresponds to a service to which a UE has subscribed, the UE receives the
corresponding HS-PDSCH sub-frame (S 176) to acquire the multicast data.
The first UE (UE #1) transmits ACK or NACK information for the received
multicast data via the HS-DPCCH after receiving the HS-PDSCH sub-frame (S 177).
The first UE (UE #1) can periodically transmit CQI information. As illustrated in FIG.
17, NACK information is transmitted since errors occur in the received data.
The second UE (UE #2) transmits ACK or NACK information for the received
multicast data via HS-DPCCH after receiving the HS-PDSCH sub-frame (S 178). The
second UE (UE #2) can periodically transmit CQI information. As illustrated in FIG. 17,
ACK information is transmitted since no errors occur in the received data.
If a number of UEs not exceeding the threshold value have transmitted NACK,
the Node B retransmits the data unit to only the UE(s) that failed to receive the data unit
without errors. The Node B also transmits an identity of each of the UEs that failed to
receive the data unit without errors over a different HS-SCCH sub-frame.
The UEs corresponding to the transmitted identities receive the HS-SCCH sub-
frame and acquire the UE identity (S 179). For a specific UE, if the acquired identity
corresponds to the UE's identity, the UE receives the corresponding HS-PDSCH sub-
frame and acquires the multicast data (S 180) and, if the acquired identity does not
correspond to the UE's identity, the UE does not receive the corresponding HS-PDSCH
sub-frame.
The first UE (UE #1) transmits ACK or NACK information for the received
multicast data via the HS-DPCCH after receiving the HS-PDSCH sub-frame (S 181).
The first UE (UE #1) can periodically transmit CQI information. As illustrated in FIG.
17, ACK information is transmitted since no errors occur in the received data.
FIG. 18 illustrates a channel for a multicast data transmission according to one
embodiment of the present invention. An F-DPCH is shared by a plurality of UEs
having subscribed to a multicast service in order to transmit UE dedicated power control
signals. The F-DPCH interfaces with several uplink DPCHs set for each of the UEs in
order to perform the power control. As illustrated in FIG. 18, power of HS-DPCCH is
adjusted according to the uplink DPCH.
FIG. 19 illustrates an HS-DSCH protocol stack according to one embodiment
of the present invention. A channel associated with an MBMS, such as MTCH, MSCH
or MCCH, is mapped to an HS-DSCH in a CRNC so that MBMS control information or
MBMS data can be transmitted to a UE via an HS-PDSCH.
FIG. 20 illustrates an MAC PDU (protocol data unit) of HS-DSCH according
to one embodiment of the present invention. AMAC-hs SDU (service data unit)
corresponds to a MAC-c/sh/m PDU.
For an MTCH, the MAC-c/sh/m PDU includes a TCTF (target channel type
field), an MBMS-Id and a MAC SDU or includes only a MAC SDU. For an MCCH or
MSCH, the MAC-c/sh/m PDU includes a TCTF and a MAC SDU or includes only a
MAC SDU.
The MAC SDU corresponds to an RLC PDU. A first bit of VF is set to 0 for a
DTCH/DCCH transmission or to 1 for an MTCH/MCCH/MSCH transmission. The VF
can be set to 1-bit or 2-bit. If the first bit of the VF is set to 1, a UE MAC recognizes
the MAC PDU as multicast data that is delivered to an upper RLC via the MTCH,
MCCH or MSCH.
FIG. 21 illustrates a MAC of a UTRAN according to one embodiment of the
present invention. For an MTCH in a MAC-c/sh/m, an MBMS-Id or a TCTF can be
attached to a MAC SDU. For an MCCH or MSCH, a TCTF can be attached to the
MAC SDU.
FIG. 22 illustrates a MAC of a UE according to one embodiment of the present
invention. For an MTCH in a MAC-c/sh/m, an MBMS-ID or a TCTF can be separated
from a MAC PDU. For an MCCH or MSCH, the TCTF can be separated from the MAC
PDU.
FIG. 23 illustrates an MBMS channel determination process according to one
embodiment of the present invention. A UE receives an MBMS service information
message via an MCCH. The UE receives information commanding the UE to receive
an access information message together with an MBMS transmission identity of a
service to which the UE has subscribed using the MBMS information message (S231).
The UE receives the access information message to perform an RRC
connection procedure using a probability factor included in the received message (S232)
and then performs the RRC connection procedure (S233). During the RRC connection
procedure, the UE informs a UTRAN whether it is able to receive the MBMS via an
HS-DSCH.
Via an MCCH, the UTRAN provides the MBMS via the HS-DSCH. The
UTRAN indicates that the MBMS shall be provided via the HS-DSCH (S234). In order
to indicate that the MBMS is to be provided, an MBMS transmission identity of the
service and HS-DSCH information for the service are sent via the MCCH. The identity
and the information are transmitted via the MBMS service information message.
FIG. 24 illustrates a process for establishing an MBMS channel according to
one embodiment of the present invention. AUTRAN indicates, via an MCCH, that an
MBMS shall be provided via an HS-DSCH (S241). In order to indicate that the MBMS
is to be provided, an MBMS transmission identity of the service and HS-DSCH
information for the service are sent via the MCCH. The identity and the information are
transmitted via an MBMS service information message.
AUE, among a plurality of UEs capable of receiving the service via the HS-
DSCH, that has not completed an RRC connection, carries out the RRC connection
(S242). During the RRC connection procedure, the UE informs a UTRAN whether it is
able to receive the MBMS via the HS-DSCH.
The UTRAN carries out an RB setup procedure for the UE capable of
receiving the MBMS via the HS-DSCH (S243). Through this procedure, the HS-DSCH
is established in the UE and the UTRAN transmits MBMS data via the established HS-
DSCH (S244). The data transmission is carried out using, for example, the HS-SCCH,
HS-DPCCH or F-DPCH.
FIG. 25 illustrates a block diagram of a radio communication apparatus
according to one embodiment of the present invention. A radio communication
apparatus according to the present invention includes an antenna unit 251, an RF (radio
frequency) unit 252, a signal processing unit 253 and a memory unit 254. The signal
processing unit 253 includes a processing unit such as a microprocessor and a digital
processor. The radio communication apparatus according to the present invention
further includes a display unit 255 for displaying specific information on a screen, a
keypad unit 256 for receiving a signal from a user, and a speaker unit 257 for outputting
a sound signal.
AUE identity and a multicast service identity are received via the antenna unit
251 and the RF unit 252. The signal processing unit 253 compares UE and multicast
service identities previously stored in the UE to the received UE and multicast service
identities, respectively.
If either the received UE or multicast service identity matches the stored UE or
multicast service identity, a frame of a data corresponding to a specific frame of a
control channel is received via the antenna and RF units 251 and 252. The signal
processing unit 253 decodes the received frame of data and transmits control
information including an ACK/NACK response signal according to the decoding result
and a CQI via the antenna unit 251 and RF unit 252.
The above-described embodiments of the present invention are explained
based on a cellular mobile communication network. Yet, the technical features of the
present invention are not limited to the cellular mobile communication network and are
applicable to a wireless communication system such as a PDA (personal digital
assistant), a notebook computer equipped with a wireless communication function and
the like. And, terms used in describing the present invention are not limited to a range of
the wireless communication system such as UMTS. The present invention is applicable
to wireless communication systems using different wireless interfaces and physical
layers such as TDMA, CDMA, FDMA and the like.
Moreover, the technical features of the present invention can be implemented
with software, firmware, hardware or one of combinations of the software, firmware
and/or hardware. Namely, the contents of the present invention are implemented with
hardware using a code, circuit chip and a hardware logic such as ASIC or with a code in
a storage medium readable by a computer such as a hard disc, a floppy disc, a tape and
the like or in a optical storage, ROM or RAM using a computer programming language.
Accordingly, the present invention enables the AMC and HARQ to be applied
to the MBMS transmission, thereby enabling more efficient data transmissions.
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 inventions. Thus, it is intended that the present invention covers the
modifications and variations of this invention provided they come within the scope of
the appended claims and their equivalents.
The foregoing embodiments and advantages are merely exemplary and are not
to be construed as limiting the present invention. The present teaching can be readily
applied to other types of apparatuses. The description of the present invention is
intended to be illustrative, and not to limit the scope of the claims. Many alternatives,
modifications, and variations will be apparent to those skilled in the art. In the claims,
means-plus-function clauses are intended to cover the structure described herein as
performing the recited function and not only structural equivalents but also equivalent
structures.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
The present invention can be applied to a mobile communication system.
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