CHUN SUNG DUCK (KR)
JUNG MYUNG CHEUL (KR)
LEE YOUNG DAE (KR)
CHUN SUNG DUCK (KR)
JUNG MYUNG CHEUL (KR)
WO2005018116A1 | 2005-02-24 |
US20030103478A1 | 2003-06-05 |
CLAIMS
1. A method of reconfiguring a common channel, the method comprising:
receiving modified channel configuration information of a first common
channel through a second common channel;
determining a starting time of reconfiguring the first common channel,
according to a type of an information element including the modified channel
configuration information; and
reconfiguring the first common channel from the determined starting time.
2. The method of claim 1, wherein the first common channel is a control
channel for a multimedia broadcast multicast service (MBMS).
3. The method of claim 2, wherein the second type information element is a
secondary common control physical channel (SCCPCH) system information.
4. The method of claim 1, wherein the second channel is a broadcast control
channel (BCCH).
5. The method of claim 1, wherein the modified channel configuration
information is transmitted using a system information block (SIB).
6. The method of claim 1, wherein the starting time is determined as a
starting point of a next modification period, if the information element corresponds to a
first type information element.
7. The method of claim 6, wherein the first type information element is used
when the first common channel is mapped to a dedicated physical channel for a
multimedia broadcast multicast service (MBMS).
8. The method of claim 6, wherein the first type information element is a
secondary common control physical channel (SCCPCH) system information MBMS.
9. The method of claim 1, wherein the first control channel is reconfigured
on receiving the modified channel configuration information, if the information element
corresponds to a second type information element.
10. The method of claim 9, wherein the second type information element is
used when at lόast a channel including the first common channel is mapped to a
physical channel.
11. The method of claim 1, wherein the starting time is determined as a
starting point
second type information element and the modified channel configuration information
include an indicator indicating the starting time of reconfiguring.
12. The method of claim 1, further comprising receiving control information
through the reconfigured first common channel.
13. A mobile terminal receiving data through a common channel, the mobile
terminal comprising:
an antenna unit for receiving modified channel configuration information of
a first common ςhannel through a second common channel;
a radio frequency module for processing the received signals at radio
frequency; and
a processor unit for determining a starting time of reconfiguring the first
common channeL according to a type of an information element including the modified
channel configuration information and for reconfiguring the first common channel from
the determined starting time.
14. The apparatus of claim 13, wherein the first common channel is a control
channel for a multimedia broadcast multicast service (MBMS).
15. The apparatus of claim 14, wherein the second type information 1 element
is a
secondary common control physical channel (SCCPCH) system information.
16. The apparatus of claim 13, wherein the second channel is a broadcast
control channel (BCCH).
17. The apparatus of claim 13, wherein the modified channel configuration
information is transmitted using a system information block (SIB).
18. The apparatus of claim 13, wherein the starting time is determined as a
starting point of a next modification period, if the information element corresponds to a
first type information element.
19. The apparatus of claim 18, wherein the first type information element is
used when the first common channel is mapped to a dedicated physical channel for a
multimedia broadcast multicast service (MBMS).
20. The apparatus of claim 18, wherein the first type information element is
a secondary common control physical channel (SCCPCH) system information MBMS.
21. The apparatus of claim 13, wherein the first control channel is
reconfigured
on receiving the modified channel configuration information, if the information element
corresponds to a second type information element.
22. The apparatus of claim 13, wherein the starting time is determined as a
starting point of a next modification period, if the information element corresponds to a
second type information element and the modified channel configuration information
include an indicator indicating the starting time of reconfiguring. |
METHOD AND APPRATUS FOR RECONFIGURING A COMMON CHANNEL
TECHNICAL FIELD
The present invention relates generally to a mobile communication system
and, more particularly, to reconfigure a common channel for a mobile communication.
BACKGROUND ART
FIG. 1 is a diagram illustrating a network structure of a universal mobile
telecommunication system (UMTS). Generally, a UMTS system 10 comprises a user
equipment (UE) 11, a UMTS terrestrial radio access network (UTRAN) 12, and a core
network (CN) 13. s Herein, the UE may be a mobile terminal in general. The UTRAN 12
comprises at least one of radio network sub-systems (RNSs) 13, and each RNS
comprises a radio network controller (RNC) 131 and at least one of Node B 132 which
is controlled by the RNC. The Node B includes at least one cell 133.
FIG. 2 is a diagram illustrating a layer structure of radio interface protocol in
mobile communication system. As shown in FIG. 2, the radio interface protocol
comprises horizontally a physical layer, a data link layer and a network layer.
Meanwhile, the radio interface protocol comprises vertically a user plane for
transmitting user data and a control plane for signaling.
The protocol layers of FIG. 2 comprises Ll (the first layer), L2 (the second
layer) and L3 (the third layer). The layers of FIG 2 correspond to 3 layers from the
bottom according to the open system interconnection (OSI) layer structure.
The first layer, i.e., the physical (PHY) layer, provides the higher layer with
information transfer service through physical channels. The PHY layer is connected to
the second layer, i.e., medium access control (MAC) layer, with transport channels and
data is transferred between MAC layer and PHY layer through the transport channels.
Meanwhile, data is transferred between the PHY layers of a transmitting side and the
PHY layer of a receiving side through the PHY channels.
The MAC layer provides a radio link control (RLC) layer with service
through logical channels. The RLC layer of L2 supports reliable data transmission and
may segment and concatenate service data units (SDUs) transferred from a higher layer.
A radio resource control (RRC) layer located at the bottom of L3 in the
protocol layers is defined on the control plane, may control the logical channels, the
transport channels and the physical channels in relation to configuration,
reconfiguration and release of radio bearers (RBs). Herein, the RB means a service
supported by L2 for data transmission between UE and UTRAN. Generally, to set up a
RB means a process for defining a protocol layers and channels for providing a specific
service, as well as a process for configuring parameters and operation, corresponding to
the specific service.
Moreover, the RRC layer may broadcast system information through a broad
control channel (BCCH). The system information regarding a cell is broadcasted to UEs
using at least one of system information block (SIB). If the system information is
modified, the UTRAN transmits BCCH modification information to the UEs through a
paging channel (PCH) or a forward access channel (FACH), for the UEs to have the
latest system information.
As an example of point-to-multipoint service, multimedia
broadcast/multicast service (MBMS) is explained as follows. The MBMS supplies a
streaming or background service using a MBMS bearer which is set up generally for
downlink transmission. A MBMS service comprises at least one session, MBMS data is
transmitted to UEs using the MBMS bearer during ongoing session. If the UE is
activated corresponding to a service to which the UE have been subscribed, the UE may
receive the service.
FIG. 3 is a diagram illustrating channels for MBMS. The UTRAN provides
UEs with MBMS using a RB. The UTRAN may set up two types of RBs, i.e., a point-
to-point RB and a point-to-multipoint RB. Herein, the point-to-point RB corresponds to
a bi-directional RB. The point-to-point RB employs a dedicated traffic channel (DTCH)
as a logical channel, a dedicated channel (DCH) as a transport channel, and a dedicated
physical channel (DPCH) or a secondary common control physical channel (SCCPCH)
as a physical chadnel.
Meanwhile, the point-to-multipoint RB corresponds to a uni-directional RB.
As shown in FIG. 3, the point-to-multipoint RB may employ the MBMS traffic channel
(MTCH) as a logical channel, the FACH as a transport channel, and the SCCPCH as a
physical channel. The MTCH is configured for each MBMS provided in a cell, is used
for transmission of user data corresponding to a MBMS on the user plane. A MBMS
control channel (MCCH) which is a logical channel is mapped to the FACH, and the
transport channel FACH is mapped to the SCCPCH. In general, one MCCH is allocated
to one cell.
According to the related art, if the SCCPCH to which the MCCH is mapped
is reconfigured, the UTRAN transmits control information through both the previously
configured SCCPCH and the reconfigured SCCPCH for a while, because the UE isn't
aware of the timing of SSCPCH reconfiguration. Therefore, the transmission of the
control information through two physical channels causes waste of radio resource.
DISCLOSURE OF INVENTION
Accordingly, the present invention is directed to a channel reconfiguration
method 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 method for reconfiguration
of a channel through which control information for point-to-multipoint service is
transmitted.
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 one embodiment,
a method of reconfiguring a common channel in a communication system comprises
receiving modified channel configuration information of a first common channel
(MCCH) through a second common channel (BCCH). The method also comprises
determining a starting time of reconfiguring the first common channel, according to a
type of an information element including the modified channel configuration
information. The method also comprises reconfiguring the first common channel from
the determined starting time.
Preferably, the starting time is determined as a starting point of a next
modification period, if the information element corresponds to a first type information
element.
Preferably, the first control channel is reconfigured on receiving the
modified channel configuration information, if the information element corresponds to a
second type information element.
Preferably, the starting time is determined as a starting point of a next
modification period, if the information element corresponds to a second type
information element and the modified channel configuration information include an
indicator indicating the starting time of reconfiguring.
In another aspect of the present invention, a mobile terminal of the present
invention comprises
The foregoing and other objects, features, aspects and advantages of the
present invention will become more apparent from the following detailed description of
the present invention when taken in conjunction with the accompanying drawings. 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.
BRIEF DESCRIPTION OF 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 embodiments of the invention and together with the description
serve to explain the principles of the invention.
FIG. 1 is a diagram illustrating a network structure of a universal mobile
telecommunication system (UMTS).
FIG. 2 ( is a diagram illustrating a layer structure of radio interface protocol in
mobile communication system.
FIG. 3 is a diagram illustrating channels for MBMS.
FIG. 4 is a diagram illustrating a method for transmitting MCCH
information through the MCCH.
FIG. 5 is a flow chart illustrating a process for reconfiguring the MCCH
according to the first embodiment.
FIG. 6' is a flow chart illustrating a process for reconfiguring the MCCH
according to the second embodiment.
FIG. 7 is a flow chart illustrating the MCCH reconfiguration method in a UE
according to the first embodiment.
FIG. 8 is a flow chart illustrating the MCCH reconfiguration method in a UE
according to the second embodiment.
FIG. 9 is a structural diagram illustrating a UE according to the present
invention.
BEST MODE FOR CARRYING OUT THE INVENTION
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 pails.
FIG. 4 is a diagram illustrating a method for transmitting MCCH
information through the MCCH. As illustrated in FIG. 4, the MCCH information is
transmitted through MCCH with two types of periods, i.e., modification period and
repetition period. The MCCH information comprises critical information and non-
critical information. The non-critical information may be modified in the modification
period or in the repetition period. But, the critical information may be modified in the
modification period. That is, the critical information is transmitted (repeatedly) during
- ■ the modification period, and modified critical information is transmitted at the start time
of the modification period. The MCCH information means a control message regarding
MBMS, and the control message may be a RRC message. The MCCH information
includes modified service information (MSI), unmodified service information (USI),
point-to-multipoint RB information and access information. Herein, the access
information message corresponds to the non-critical information, and the other
information message corresponds to the critical information. The access information is
transmitted per aij access period which is equal to or less than the repetition period.
Further, the repetition period may comprise multiple of the access period.
If the UTRAN transmits a control message corresponding to a MBMS, the
control message includes a MBMS transmission identity. Herein, the MBMS
transmission identity comprises a MBMS session identity and a MBMS service identity.
For example, when the UTRAN transmits the MBMS MSI message, the MBMS MSI
message includes the MBMS transmission identity and service information
corresponding to, fshe MBMS transmission identity.
The UTRAN periodically transmits information regarding whether the
MCCH information is modified, thorough a MBMS notification Indicator channel
(MICH). Therefore, if a UE wants to receive a specific MBMS data but a session of the
specific MBMS doesn't start yet, the UE receives information through a MICH instead
of a MCCH or a MTCH.
The UTRAN may modify the MCCH information by generating, adding,
changing or deleting parameters from the MCCH information. The UTRAN transmits a
MICH message and a MSI message to notify the UE of whether the MCCH information
is going to be modified during the modification period. The MSI message includes at
least one service identity corresponding to each service modified in the modification
period, and information for operating the UE subscribed to the service. Herein, the
service identity may be a MBMS transmission identity. The MBMS transmission
identity may comprise a MBMS service identity identifying a service. Also, the MBMS
transmission identity may comprise combination of a MBMS session identity and a
MBMS service identity, the MBMS session identity identifies a service session. A
service identity corresponding to a service not being modified during the modification
period, among the services currently provided in a cell, is transmitted using a USI
message. Herein, the service identity may be a MBMS transmission identity
corresponding to the service.
When a service session of a MBMS starts, the UTRAN transmits, through
the MICH, a notification indicator (NI) notifying UEs of receiving information through
the MCCH. If a UE receives the NI from the UTRAN, the UE is trying to receive the
MBMS data. If a UE receives a NI notifying the service modification through the MICH,
the UE receives the MCCH information during the modification period indicated by the
NI. During receiving the MCCH information, the UE receives the MSI message, and
checks whether the MBMS is modified. If the UE detects modification of the MBMS,
the UE receives modified MCCH information. Meanwhile, the UE receives the MSI and.,
the USI messages which are transmitted during the modification period, and may
acquire a service list listing all services currently provided in the cell in the modification
period'.
A UE trying to receive a MBMS service using a point-to-multipoint RB
receives MCCH information including RB information through a MCCH, and sets up
the point-to-multipoint RB in itself using the MCCH information. After setting up the
point-to-multipoint RB, the UE receives MBMS data through the physical channel
SCCPCH to which the ' logical channel MTCH is mapped.
The UTRAN may transmit the MBMS data through the MTCH. Herein, as
illustrated FIG. 3, the UTRAN transmits a scheduling message to the UE through a
MBMS scheduling channel (MSCH) corresponding to the SCCPCH to which the
MTCH is mapped. The scheduling message includes information regarding a start point
and an ending point of MBMS data transmission in a scheduling period. Therefore, the
UTRAN informs the UE of a transmission period of scheduling information (scheduling
period) in advance.
FIG. 5 is a flow chart illustrating a process for reconfiguring the MCCH
according to the first embodiment. As shown in FIG. 5, the UTRAN broadcasts SIB
including secondary CCPCH system information MBMS, through the BCCH. Herein,
the secondary CCPCH system information MBMS includes MCCH reconfiguration
information. Then, a UE is able to be aware the modification of the BCCH channel
information, and receives the secondary CCPCH system information MBMS through
the BCCH. The UE is able to acquire the MCCH reconfiguration information from the
secondary CCPCH system information MBMS S51.
The UE doesn't reconfigure the MCCH until the modification period in
which the~UE receives the secondary CCPCH system information MBMS is finished. If
it is necessary to receive the MCCH information, the UE is able to receive the MCCH
information according to the previous configuration S52.
When the, modification period in which the secondary CCPCH system
information MBMS is finished, the UE starts to reconfigure the MCCH using the
MCCH reconfiguration information S53. Then, the UTRAN starts to transmit signals
through the reconfigured MCCH, and the UE starts to receive signals through the
reconfigured MCCH also S54.
FIG. 6 is a flow chart illustrating a process for reconfiguring the MCCH
according to the second embodiment. The embodiment illustrated in FIG. 6 corresponds
to a case that the reconfiguration of the MCCH starts at the starting time of next
modification period.
In FIG. 6, a UTRAN broadcasts SIB including secondary CCPCH system
information, through the BCCH. Herein, the secondary CCPCH system information
includes MCCH reconfiguration information. Then, a UE is able to be aware the
modification of the BCCH channel information, and receives the secondary CCPCH
system information through the BCCH. The UE is able to acquire the MCCH
reconfiguration information from the secondary CCPCH system information S61.
Then, the UE decides starting time of the MCCH reconfiguration according
to the secondary CCPCH system information S62. Herein, the UE may decide the
starting time of the MCCH reconfiguration according to an indication which is included
in the secondary CCPCH system information. Also, the UE may decide the starting time
of the MCCH reconfiguration according to the secondary CCPCH system information
without indication.
According to the MCCH reconfiguration method using the indication, the
UE receives the secondary CCPCH system information and checks whether the
secondary CCPCH system information includes the indication. If the secondary CCPCH
system information doesn't include the indication, the UE may start to reconfigure the
MCCH at the starting time of the next modification period. But, if the secondary
CCPCH system information includes the indication, the UE may start to reconfigure the
MCCH on receiving the secondary CCPCH system information. Meanwhile, if the
secondary CCPCH system information includes the indication, the UE may start to
reconfigure the MCCH at the starting time of the next modification period. Also, if the
secondary CCPCH system information doesn't include the indication, the UE may start
to reconfigure the MCCH on receiving the secondary CCPCH system information.
Furthermore, if the indication indicates that the starting time of the MCCH
reconfiguration corresponds to the starting time of the next modification period, the UE
may start to reconfigure the MCCH at the starting time of the next modification period,
according to the indication. But, if the indication indicates immediate reconfiguration of
MCCH, the UE may start to reconfigure the MCCH on receiving the secondary CCPCH
system information.
According to the MCCH reconfiguration method without the indication, the
UE receives the secondary CCPCH system information without indication, and may
start to reconfigure the MCCH at the starting time of the next modification period.
Herein, the secondary CCPCH system information includes other channel
reconfiguration information than the MCCH, the UE may decide to employ the channel
reconfiguration information on receiving the secondary CCPCH system information.
In case that the UE starts to reconfigure the MCCH at the starting time of the
next modification period, the UE may receive signals through the MCCH which is not
reconfigured yet, until the end time of the present modification period (i.e. the starting
time of the next modification period) S63. When the next modification period starts, the
UE starts to reconfigure the MCCH S64. After the reconfiguring of the MCCH, the
UTRAN transmits control information through the reconfigured MCCH and the UE
receives the control information through the reconfigured MCCH S65.
FIG. 7 is a flow chart illustrating the MCCH reconfiguration method in a UE
according to the first embodiment. As shown in FIG. 7, a UE receives a SIB including
the MCCH reconfiguration information through the BCCH, in a modification period
S71. And, the UE examines which information element of the SIB includes the MCCH
reconfiguration information S72.
If the MCCH reconfiguration information is included in Secondary CCPCH
system information MBMS which is included in the SIB, the UE may start to
reconfigure the MCCH at the starting time of the next modification period S73.
But, if the MCCH reconfiguration information is included in Secondary
CCPCH system information which is included in the SIB, the UE may start to
reconfigure the MCCH on receiving the Secondary CCPCH system information S74.
FIG. 8Js a flow chart illustrating the MCCH reconfiguration method in a UE
according to the second "embodiment. As shown in FIG. 8, a UE receives a SIB
including the MCCH reconfiguration information through the BCCH, in a modification
period S81. And, the UE examines which information element of the SIB includes the
MCCH reconfiguration information S82.
If the MCCH reconfiguration information is included in Secondary CCPCH
system information MBMS which is included in the SIB, the UE may start to
reconfigure the MCCH at the starting time of the next modification period S 83.
But, if the MCCH reconfiguration information is included in Secondary
CCPCH system information which is included in the SIB, the UE may determine the
starting time of the MCCH reconfiguration using an indication which is included in the
Secondary CCPCH system information. That is, the UE may start to reconfigure the
MCCH at the starting time of the next modification period S84 or on receiving the
Secondary CCPCH system information S85, according to the indication.
FIG. 9 is a structural diagram illustrating a UE according to the present
invention. As shown in FIG. 9, the UE comprises an antenna unit 91, a radio frequency
(RF) unit 92, a signal processing unit 93 and memory unit 94. The signal processing
unit 93 includes a procession unit such as a micro process or a digital signal processor.
Further, the UE may also comprise a display unit 95, a key pad unit 96 and speaker unit
97.
The UE receives signals through the MCCH and the BCCH using the
antenna unit 91 and the RF unit 92. The signal processing unit 93 reconfigures the
MCCH using the signals received through the MCCH and the BCCH according to
' above-explained process."
INDUSTRIAL APPLICABILITY
The present invention is applicable to a personal digital assistant and a
notebook computer capable of mobile communication as well as a mobile phone. Also,
the preferred embodiments may be implemented as a method, apparatus or article of
manufacture using standard programming and/or engineering techniques to produce
software, firmware, hardware, or any combination thereof. The term "article of
manufacture" as used herein refers to code or logic implemented in hardware logic (e.g.,
an integrated circuit chip, Field Programmable Gate Array (FPGA), Application
Specific Integrated Qircuit (ASIC) 5 etc.) or a computer readable medium (e.g., magnetic
storage medium (e.g., hard disk drives, floppy disks, tape, etc.), optical storage (CD-
ROMs, optical disks, etc.), volatile and non- volatile memory devices (e.g., EEPROMs,
ROMs, PROMs, RAMs, DRAMs, SRAMs, firmware, programmable logic, etc.).
Although various embodiments of the present invention have been described
with reference to a node-B, the present invention may be applied to a base station or any
other type of fixed communication station.
It will be apparent to those skilled in the art that various modifications and
variations may 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.