Information Acquiring Method and Base Station
Technical Field
The present invention relates to the field of wireless communications and, in
particular to an information acquiring method, for acquiring reception status
information of a multimedia broadcast multicast service of user equipment, and a base
station.
Background Art
Currently, in order to better satisfy the demands of mobile users in experiencing
multimedia broadcast multicast services (MBMSs), and to more efficiently use
limited spectral resources, the 3rd generation partnership project (3GPP) supports
transmission of MBMSs in long-term evolution (LTE) R9 by using a multicast
broadcast single frequency network (MBSFN). Transmission of MBMSs by using an
MBSFN needs multiple base stations participating in the transmission to use
completely identical time-frequency resources to transmit identical data at the same
time. In comparison with a transmission mode of single-cell MBMS, the transmission
mode of the MBSFN is able to more efficiently avoid inter-cell interference and bring
extra diversity gains. Therefore, it can greatly improve the service reception
capabilities of reception users.
However, in the implementation of the present invention, the inventors found that
following defects exist in the prior art: in the existing LTE MBMS standards, for the
ease of realization and convenient deployment, user equipment receiving a MBMS
does not report its MBMS reception status to the base station where it is located.
When the user equipment receiving the MBMS is moved out of a corresponding
MBSFN area, as a target base station cannot acquire MBMS reception status
information of the user equipment, the target base station cannot offer corresponding
MBMS service to the user equipment, possibly resulting in interruption of the MBMS
of the user equipment, and the continuity of the MBMS of the user equipment being
not able to be guaranteed.

It should be noted that the above description of the background art is merely
provided for clear and complete explanation of the present invention and for easy
understanding by those skilled in the art. And it should not be understood that the
above technical solution is known to those skilled in the art as it is described in the
background art of the present invention.
Summary of the Invention
An object of the embodiments of the present invention is to provide an
information acquiring method and a base station. When user equipment is handed
over between cells, a source base station of the user equipment notifies a target base
station of MBMS reception status information of the user equipment, thereby
guaranteeing the continuity of the MBMS of the user equipment.
According to an aspect of the embodiments of the present invention, there is
provided an information acquiring method, comprising:
receiving by a target base station reception status information of a multimedia
broadcast multicast service of user equipment reported by a source base station when
the user equipment is handed over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a multimedia broadcast multicast service, or
information indicating that the user equipment finishes receiving a multimedia
broadcast multicast service.
According to another aspect of the embodiments of the present invention, there is
provided an information acquiring method, comprising:
reporting by a source base station of user equipment to a target base station
reception status information of a multimedia broadcast multicast service of the user
equipment when the user equipment is handed over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a multimedia broadcast multicast service, or
information indicating that the user equipment finishes receiving a multimedia
broadcast multicast service.

According to a further aspect of the embodiments of the present invention, there
is provided a target base station, comprising:
a first information acquiring unit configured to receive reception status
information of a multimedia broadcast multicast service of user equipment reported
by a source base station when the user equipment is handed over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a multimedia broadcast multicast service, or
information indicating that the user equipment finishes receiving a multimedia
broadcast multicast service.
According to still another aspect of the embodiments of the present invention,
there is provided a source base station, comprising:
an information transmitting unit configured to report to a target base station
reception status information of a multimedia broadcast multicast service of user
equipment when the user equipment is handed over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a multimedia broadcast multicast service, or
information indicating that the user equipment finishes receiving a multimedia
broadcast multicast service.
According to still another aspect of the embodiments of the present invention,
there is provided a computer-readable program, wherein when the program is
executed in a target base station, the program enables a computer to carry out the
information acquiring method as described above in the target base station.
According to still another aspect of the embodiments of the present invention,
there is provided a storage medium in which a computer-readable program is stored,
wherein the computer-readable program enables a computer to carry out the
information acquiring method as described above in a target base station.
According to still another aspect of the embodiments of the present invention,
there is provided a computer-readable program, wherein when the program is
executed in a source base station, the program enables a computer to carry out the
information acquiring method as described above in the source base station.

According to still another aspect of the embodiments of the present invention,
there is provided a storage medium in which a computer-readable program is stored,
wherein the computer-readable program enables a computer to carry out the
information acquiring method as described above in a source base station.
The advantage of the embodiments of the present invention exists in: the source
service base station of the user equipment notifies the target base station of reception
status information of a multimedia broadcast multicast service of the user equipment
when the user equipment is handed over between cells, thereby guaranteeing the
continuity of the MBMS of the user equipment.
With reference to the following description and drawings, the particular
embodiments of the present invention are disclosed in detail, and the principle of the
present invention and the manners of use are indicated. It should be understood that
the scope of the embodiments of the present invention is not limited thereto. The
embodiments of the present invention contain many alternations, modifications and
equivalents within the spirits and scope of the terms of the appended claims.
Features that are described and/or illustrated with respect to one embodiment may
be used in the same way or in a similar way in one or more other embodiments and/or
in combination with or instead of the features of the other embodiments.
It should be emphasized that the term "comprises/comprising" when used in this
specification is taken to specify the presence of stated features, integers, steps or
components but does not preclude the presence or addition of one or more other
features, integers, steps, components or groups thereof.
Brief Description of the Drawings
The above and other objects, features and advantages of the present invention will
be apparent from the following detailed description in conjunction with the drawings,
in which:
Figure 1 is a flowchart of the information acquiring method of embodiment 1 of
the present invention;
Figure 2 is a flowchart of the information acquiring method of embodiment 2 of

the present invention;
Figure 3 is a flowchart of the method for acquiring reception status information
by the source base station of embodiment 2 of the present invention;
Figure 4 is a flowchart of the method for acquiring reception status information
by the source base station of embodiment 2 of the present invention;
Figure 5 is a structural schematic diagram of the target base station of
embodiment 3 of the present invention;
Figure 6 is a structural schematic diagram of the source base station of
embodiment 4 of the present invention;
Figure 7 is a structural schematic diagram of the second information acquiring
unit of Figure 6;
Figure 8 is a structural schematic diagram of the second information acquiring
unit of Figure 6; and
Figure 9 is a schematic diagram of the interchange of the reception status
information of MBMS of the user equipment between a source base station and a
target base station of the present invention.
Detailed Description of the Invention
The foregoing and other features of the embodiments of the present invention will
become apparent with reference to the drawings and the following description. These
embodiments are illustrative only and are not intended to limit the present invention.
For easy understanding of the principle and embodiments of the present invention by
those skilled in the art, the principle of the embodiments of the present invention shall
be described taking MBMS of an LTE/LTE-A system as an example. However, it
should be understood that the present invention is not limited to such a system, and it
is applicable to other systems related to report of MBMS reception status information.
Fig. 1 is a flowchart of the information acquiring method of embodiment 1 of the
present invention. As shown in Fig. 1, the method comprises:
step 101: receiving by a target base station (target eNB) reception status
information of a multimedia broadcast multicast service (MBMS) of user equipment

reported by a source base station (source eNB) when the user equipment is handed
over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a MBMS information, or information indicating that
the user equipment finishes receiving a MBMS information.
In this way, the target eNB obtains MBMS reception status of the user equipment
through the information reported by the source eNB, thereby guaranteeing the
continuity of the MBMS of the user equipment.
In this embodiment, the source eNB reports the reception status information to
the target eNB by using a UE-MBMS reception report message; however, it is not
limited to the above message, and any other message may be used to report the
reception status information. For example, the reception status information may be
reported via an MBMS on message indicating that the UE-MBMS is being received,
or the reception status information may be reported via an MBMS off message
indicating that the reception of the UE-MBMS is finished.
In this embodiment, when the source eNB reports information containing
indication on that the user equipment is receiving the MBMS or finishes reception of
the MBMS to the target eNB, MBMS information may also be reported, the service
information comprising one or more pieces of following information:
MBSFN area identity, MBMS identity, MBMS session identity, temporary
mobile group identity (TMGI) and a carrier frequency carrying an MBMS.
In this embodiment, as shown in Fig. 1, the method may optionally further
comprise: step 102: returning by the target eNB a reception confirm message to the
source eNB; wherein, in this embodiment, the target eNB may reply a confirm
message to the source eNB via a UE-MBMS reception confirm message; however, it
is not limited to the above message, and any other message may be used for replying a
confirm message.
It can be seen from the above embodiment that when the user equipment is
handed over between the cells, the source service eNB of the user equipment notifies
the target eNB of the MBMS reception status information of the user equipment,

thereby guaranteeing the continuity of the MBMS of the user equipment. Furthermore,
MBSFN area identity, MBMS identity, MBMS session identity, TMGI and a carrier
frequency carrying an MBMS, etc., may also be notified.
In this embodiment, after the target eNB receives the reception status information
reported by the source eNB, when the target eNB is capable of providing the MBMS
to the user equipment, the method further comprises: updating by the target eNB the
service information of the MBMS received by the user equipment; that is, the service
information may comprise MBSFN area identity, MBMS identity, MBMS session
identity, TMGI and a carrier frequency carrying an MBMS.
In this embodiment, when the target eNB is incapable of providing the MBMS to
the user equipment, the method further comprises:
providing by the target eNB the MBMS to the user equipment through a
broadcast or a unicast mode. Examples are as follows:
first, when a target cell belong to a reserved cell of the MBSFN area, the target
eNB provides the MBMS through a broadcast or a unicast mode;
second, when a target cell does not belong to the MBSFN area providing the
MBMS, the target cell joins in the MBSFN area providing the MBMS, and the target
eNB provides the MBMS through broadcast;
third, when a target cell does not belong to the MBSFN area providing the
MBMS, the target eNB may set up a link with the provider of the MBMS, and provide
the MBMS to the user equipment through a unicast mode; and
fourth, when a target cell has no adequate resources for providing the MBMS, the
target eNB may set up a link with the provider of the MBMS, and provide the MBMS
to the user equipment through a unicast mode.
It can be seen from the above embodiment that when the user equipment is
handed over between the cells, the source eNB of the user equipment notifies the
target eNB of the MBMS reception status information of the user equipment; and
after receiving the reception status information, the target eNB may provides
corresponding MBMS to the user equipment through a broadcast or a unicast mode,
thereby guaranteeing the continuity of the MBMS of the user equipment.

Embodiment 2
Fig. 2 is a flowchart of the information acquiring method of embodiment 2 of the
present invention. As shown in Fig. 2, the method comprises:
reporting by a source eNB of user equipment a target eNB reception status
information of a MBMS of the user equipment to when the user equipment is handed
over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving an MBMS (MBMS on), or information indicating that
the user equipment finishes receiving an MBMS (MBMS off).
In this embodiment, besides the information containing indication on that the user
equipment is receiving the MBMS or finishes reception of the MBMS, the source
eNB may also report MBMS service information to the target eNB, the service
information being as described in embodiment 1, which shall not be described herein
any further.
In this embodiment, the method may optionally further comprise: acquiring by
the source eNB a reception confirm message returned by the target eNB,
wherein, in this embodiment, the source eNB may report the reception status
information to the target eNB by using a UE-MBMS reception report message;
however, it is not limited to the above message, and any other message may be used
to report the reception status information.
In this embodiment, the method may further comprise: acquiring the reception
status information by the source eNB. The method for acquiring the reception status
information by the source eNB shall be described below in detail with reference to
Figs. 3 and 4.
Fig. 3 is a flowchart of the method for acquiring the reception status information
by the source eNB of embodiment 2. As shown in Fig. 2, the method comprises:
step 301: reporting the reception status information by the user equipment to the
source eNB, so that the source eNB acquires the reception status information;
wherein, when the user equipment is receiving a new MBMS and the user
equipment has not fed back any reception status information on the MBMS before to

any base station or the source eNB, the user equipment may transmit the reception
status information to the source eNB via an MBMS reception status report (MBMS on)
message (is receiving); however, it is not limited to such a message, and any other
message may be used; wherein, if the user equipment reports the information to the
source eNB only when the user equipment has not reported an MBMS reception
status to any base station, it may be avoided that the user equipment reports the
reception status information in each time of being handed over to a new base station;
after finishing reception of corresponding MBMS, the user equipment transmits
an MBMS reception status report (MBMS off) message (reception finished) to the
source eNB; however, it is not limited to such a message, and any other message may
be used;
furthermore, the above messages may comprise corresponding MBMS service
information, such as MBSFN area identity, MBMS identity, MBMS session identity,
TMGI, and a carrier frequency carrying an MBMS, etc.;
step 302: transmitting a confirm message by the source eNB to the user
equipment after the source eNB receives the reception status information reported by
the user equipment;
wherein, step 302 is optional, and an MBMS reception status confirm message
may be used as the confirm message; however, it is not limited to such a message, and
any other message may be used.
It can be seen from above that the source eNB is enabled to obtain the reception
status information of an MBMS of the user equipment through the report process
initiated by the user equipment.
Fig. 4 is a flowchart of the method for acquiring reception status information by
the source base station of embodiment 2. As shown in Fig. 4, the method comprises:
step 401: transmitting by the source eNB to the user equipment a request message
instructing the user equipment to report the reception status information of an MBMS;
wherein, the source eNB may broadcast an MBMS reception status request
message, indicating that the user equipment within its serving area reports the
reception status information of the MBMS to the source eNB;

step 402: reporting the reception status information by the user equipment
according to the request message after receiving the request message broadcasted by
the source eNB, so that the source eNB acquires the reception status information;
wherein, the user equipment may report the reception status information via a
response message;
if the user equipment is receiving a corresponding MBMS and the user equipment
has not fed back any reception status information on the MBMS before to any base
station or the source eNB, the user equipment may indicate its current reception status
to the source eNB via an MBMS reception status response (MBMS on) message (is
receiving); wherein the time of transmission of the response message may be the time
when reception of the broadcast service is started, or the time when the handover is
prepared;
furthermore, if the user equipment finishes the reception of corresponding MBMS,
the user equipment may inform the source eNB that its corresponding reception of
MBMS is finished by transmitting an MBMS reception status response (MBMS off)
message (reception is finished), the response message being transmitted at the time of
finishing the reception of the service;
the above two messages may further comprise corresponding MBMS service
information, such as MBSFN area identity, MBMS session identity, MBMS session
identity, TMGI, and a carrier frequency carrying an MBMS, etc.
It can be seen from above that the source eNB is enabled to obtain the reception
status information of an MBMS of the user equipment through the report process
initiated by the base station at the network side.
It can be seen from the above embodiment that when the user equipment is
handed over between the cells, the source service eNB of the user equipment notifies
the target eNB of the MBMS reception status information of the user equipment; and
after receiving the reception status information, the target eNB may provides
corresponding MBMS to the user equipment through a broadcast or a unicast mode,
thereby guaranteeing the continuity of the MBMS of the user equipment. Wherein, the
source eNB may obtain the reception status information of the user equipment via the

report process initiated by the network side or via the report process initiated by the
user equipment
An embodiment of the present invention further provides a source eNB and a
target eNB, as described in embodiment 3 and embodiment 4 below. As the principles
of the source eNB and the target eNB for solving problems are similar to those of the
above-described information acquiring methods based on a source eNB and a target
eNB, the implementation of the methods may be referred to for the implementation of
the source eNB and the target eNB, and the repeated parts shall not be described any
further.
Embodiment 3
Fig. 5 is a functional structural schematic diagram of the target eNB of
embodiment 3 of the present invention. As shown in Fig. 5, the target eNB comprises
a first information acquiring unit 501; wherein the first information acquiring unit 501
is configured to receive reception status information of an MBMS of user equipment
reported by a source base station when the user equipment is handed over between
cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving an MBMS (MBMS on), or information indicating that
the user equipment finishes receiving an MBMS (MBMS off).
It can be seen from the above embodiment that when the user equipment is
handed over between the cells, the source eNB of the user equipment notifies the
target eNB of the MBMS reception status information of the user equipment, thereby
guaranteeing the continuity of the MBMS of the user equipment.
In this embodiment, the source eNB may further report the service information to
the target eNB. In this way, the first information acquiring unit 501 may further
acquire the service information, the service information being as described in
embodiment 1, which shall not be described any further.
As shown in Fig. 5, the target eNB may further comprise a first transmitting unit
502 configured to return a reception confirm message to the source eNB after
receiving the reception status information.

In the above embodiment, the message used by the source eNB in transmitting
the reception status information and the message used in transmitting the reception
confirm message are as described in embodiment 1 and embodiment 2, which shall
not be described any further.
In this embodiment, as shown in Fig. 5, the target eNB may further comprise an
information updating unit 503 configured to update the service information of the
MBMS received by the user equipment when the target base station is capable of
providing to the user equipment the MBMS. Wherein, the service information is as
described in embodiment 1, which shall not be described any further.
As shown in Fig. 5, the target base station further comprises a service providing
unit 504 configured to provide to the user equipment the MBMS through a broadcast
or a unicast mode after the target base station acquires the reception status
information and when the target base station is incapable of providing to the user
equipment the MBMS. Wherein, using a broadcast or a unicast mode by the service
providing unit 504 to provide MBMS is as described in embodiment 1, which shall
not be described any further.
It can be seen from the above embodiment that when the user equipment is
handed over between the cells, the source service eNB of the user equipment notifies
the target eNB of the MBMS reception status information of the user equipment,
thereby guaranteeing the continuity of the MBMS of the user equipment; furthermore,
after receiving the MBMS reception status information of the user equipment, the
target eNB performs corresponding operations according to whether it is capable of
providing to the user equipment the MBMS, so as to provide corresponding MBMS to
the user equipment.
Embodiment 4
Fig. 6 is a structural schematic diagram of the source eNB of embodiment 4 of
the present invention. As shown in Fig. 6, the source eNB comprises an information
transmitting unit 601 configured to report reception status information of an MBMS
of user equipment to a target eNB when the user equipment is handed over between
cells;

wherein the reception status information comprises information indicating that
the user equipment is receiving an MBMS, or information indicating that the user
equipment finishes receiving an MBMS.
It can be seen from the above embodiment that when the user equipment is
handed over between the cells, the source eNB of the user equipment notifies the
target eNB of the MBMS reception status information of the user equipment, thereby
guaranteeing the continuity of the MBMS of the user equipment.
In this embodiment, the source eNB may further report MBMS service
information in reporting to the target eNB information indicating that the user
equipment is receiving or finishes the reception of the MBMS, the service information
being as described in embodiment 1, which shall not be described any further.
Before the source eNB reports the reception status information to the target eNB,
the source eNB may obtain the reception status information via a report process
initiated by the network side or via a report process initiated by the user equipment.
Therefore, as shown in Fig. 6, the source eNB may further comprise a second
information acquiring unit 602 configured to acquire the reception status information.
In obtaining the reception status information via a report process initiated by the
user equipment, as shown in Fig.7, the second information acquiring unit 602 may
comprise a first information receiving unit 701; wherein, the first information
receiving unit 701 is configured to receive the reception status information reported
by the user equipment, so as to acquire the reception status information.
In such a case, the source eNB may further comprise a confirm message
transmitting unit 702 configured to return a reception confirm message to the user
equipment after receiving the reception status information transmitted by the user
equipment. Detailed process is as described in embodiment 2, which shall not be
described herein any further. Wherein, the confirm message transmitting unit 702 is
optional.
In obtaining the reception status information via a report process initiated by the
network side, as shown in Fig.8, the second information acquiring unit 602 comprises
a request message transmitting unit 801 and an information receiving unit 802;

wherein,
the request message transmitting unit 801 is configured to transmit a request
message to the user equipment instructing the user equipment to report the reception
status information; and the information receiving unit 802 is configured to receive the
reception status information reported by the user equipment according to the request
message transmitted by the request message transmitting unit 801, so as to acquire the
reception status information.
It can be seen from the above embodiment that when the user equipment is
handed over between the cells, the source eNB of the user equipment notifies the
target eNB of the MBMS reception status information of the user equipment, thereby
guaranteeing the continuity of the MBMS of the user equipment; wherein, the source
eNB may obtain the reception status information of the user equipment via a report
process initiated by the network side or via a report process initiated by the user
equipment.
Following description is given to a process of the interchange of the reception
status information of MBMS of the user equipment between a source base station and
a target base station with reference to Fig. 9.
Fig. 9 is a schematic diagram of the interchange of the reception status
information of MBMS of the user equipment between a source base station and a
target base station of the present invention. As shown in Fig. 9, following steps are
employed:
step 901: acquiring by the source eNB the reception status information of MBMS
of the user equipment;
wherein, the information may be acquired by using the methods as described in
Figs. 3 and 4 of embodiment 2, which shall not be described herein any further;
step 902: transmitting reception status information of moving user equipment by
the source eNB to the target eNB when the user equipment is handed over between
cells;
wherein, the reception status information may be carried by a UE-MBMS
reception report message; besides the information indicating that the user equipment

is receiving or finishes the reception of the MBMS, the reception status information
may further comprise MBMS service information, which are as described in above
embodiments, and shall not be described herein any further;
step 903: returning a confirm message by the target eNB to the source eNB after
the target eNB receives the reception status information;
wherein, the confirm message may be returned to the source eNB via a
UE-MBMS reception confirm message, and this step is optional;
step 904: updating service information of the user equipment for receiving the
MBMS by the target eNB after the target eNB receives the report and when the target
eNB is capable of providing corresponding MBMS to the user equipment;
step 905: providing the MBMS by the target eNB through a unicast mode or a
broadcast mode after the target eNB receives the report and when the target eNB is
incapable of providing corresponding MBMS to the user equipment.
An embodiment of the present invention further provides a computer-readable
program, wherein when the program is executed in a target eNB, the program enables
a computer to carry out the information acquiring method as described in embodiment
1 in the target eNB.
An embodiment of the present invention further provides a storage medium in
which a computer-readable program is stored, wherein the computer-readable
program enables a computer to carry out the information acquiring method as
described in embodiment 1 in a target eNB.
An embodiment of the present invention further provides a computer-readable
program, wherein when the program is executed in a source eNB, the program
enables a computer to carry out the information acquiring method as described in
embodiment 2 in the source eNB.
An embodiment of the present invention further provides a storage medium in
which a computer-readable program is stored, wherein the computer-readable
program enables a computer to carry out the information acquiring method as
described in embodiment 2 in a source eNB.
The above apparatuses and methods of the present invention may be implemented

by hardware, or by hardware in combination with software. The present invention
relates to such a computer-readable program that when the program is executed by a
logic device, the logic device is enabled to carry out the apparatus or components as
described above, or to carry out the methods or steps as described above. The present
invention also relates to a storage medium for storing the above program, such as a
hard disk, a floppy disk, a CD, a DVD, and a flash memory, etc.
The present invention is described above with reference to particular
embodiments. However, it should be understood by those skilled in the art that such a
description is illustrative only, and not intended to limit the protection scope of the
present invention. Various variants and modifications may be made by those skilled in
the art according to the spirits and principle of the present invention, and such variants
and modifications fall within the scope of the present invention.

We Claim:
1. An information acquiring method, comprising:
receiving by a target base station reception status information of a multimedia
broadcast multicast service of user equipment reported by a source base station when
the user equipment is handed over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a multimedia broadcast multicast service, or
information indicating that the user equipment finishes receiving a multimedia
broadcast multicast service.
2. The method according to claim 1, wherein the reception status information
further comprises service information of the multimedia broadcast multicast services
the service information comprising one or more pieces of the following information:
multicast broadcast single frequency network area ID, multimedia broadcast
multicast service ID, multimedia broadcast multicast service session ID, temporary
mobile group identity, and the carrier frequency carrying the multimedia broadcast
multicast service.
3. The method according to claim 1, wherein the method further comprises
returning by the target base station a reception confirm message to the source base
station.
4. The method according to claim 1, wherein when the target base station is
capable of providing the multimedia broadcast multicast service to the user equipment,
the method further comprises: updating by the target base station the service
information of the multimedia broadcast multicast service received by the user
equipment.
5. The method according to claim 1, wherein when the target base station is
incapable of providing the multimedia broadcast multicast service
to the user equipment, the method further comprises:
providing by the target base station the multimedia broadcast multicast service to

the user equipment through a broadcast or a unicast mode.
6. The method according to claim 5, wherein the target base station provides the
multimedia broadcast multicast service through a broadcast or a unicast mode when a
target cell belongs to a reserved cell of a multicast broadcast single frequency network
area;
when a target cell does not belong to the multicast broadcast single frequency
network area providing the multimedia broadcast multicast service, the target cell
joins in the multicast broadcast single frequency network area providing the
multimedia broadcast multicast service, and the target base station provides the
multimedia broadcast multicast service through broadcast;
when a target cell does not belong to the multicast broadcast single frequency
network area providing the multimedia broadcast multicast service, the target base
station provides the multimedia broadcast multicast service through a unicast mode;
and
when a target cell has no adequate resources for providing the multimedia
broadcast multicast service, the target base station provides the multimedia broadcast
multicast service through a unicast mode.
7. An information acquiring method, comprising:
reporting by a source base station of user equipment to a target base station
reception status information of a multimedia broadcast multicast service of the user
equipment when the user equipment is handed over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a multimedia broadcast multicast service, or
information indicating that the user equipment finishes receiving a multimedia
broadcast multicast service.
8. The method according to claim 7, wherein the reception status information
further comprises service information of the multimedia broadcast multicast service,
the service information comprising one or more pieces of the following information:
multicast broadcast single frequency network area ID, multimedia broadcast
multicast service ID, multimedia broadcast multicast service session ID, temporary

mobile group identity, and the carrier frequency carrying the multimedia broadcast
multicast service.
9. The method according to claim 7, wherein the method further comprises
acquiring by the source base station the reception status information.
10. The method according to claim 9, wherein the step of acquiring by the source
base station the reception status information comprises:
receiving by the source base station the reception status information reported by
the user equipment, so as to acquire the reception status information.
11. The method according to claim 9, wherein the step of acquiring by the source
base station the reception status information comprises:
transmitting by the source base station to the user equipment a request message
indicating that the user equipment reports the reception status information; and
receiving by the source base station the reception status information reported by
the user equipment in response to the request message, so as to acquire the reception
status information.
12. A target base station, comprising:
a first information acquiring unit configured to receive reception status
information of a multimedia broadcast multicast service of user equipment reported
by a source base station when the user equipment is handed over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a multimedia broadcast multicast service, or
information indicating that the user equipment finishes receiving a multimedia
broadcast multicast service.
13. The target base station according to claim 12, wherein the target base station
further comprises a first transmitting unit configured to return a reception confirm
message to the source base station after receiving the reception status information.
14. The target base station according to claim 12, wherein the target base station
further comprises an information updating unit configured to update the service
information of the multimedia broadcast multicast service received by the user
equipment when the target base station is capable of providing to the user equipment

the multimedia broadcast multicast service.
15. The target base station according to claim 12, wherein the target base station
further comprises a service providing unit configured to provide to the user equipment
the multimedia broadcast multicast service through a broadcast or a unicast mode
when the target base station is incapable of providing to the user equipment the
multimedia broadcast multicast service.
16. A source base station, comprising:
an information transmitting unit configured to report to a target base station
reception status information of a multimedia broadcast multicast service of user
equipment when the user equipment is handed over between cells;
wherein the reception status information comprises information indicating that
the user equipment is receiving a multimedia broadcast multicast service, or
information indicating that the user equipment finishes receiving a multimedia
broadcast multicast service.
17. The source base station according to claim 16, wherein the source base station
further comprises a second information acquiring unit configured to acquire the
reception status information.
18. The source base station according to claim 17, wherein the second
information acquiring unit is used to receive the reception status information reported
by the user equipment, so as to acquire the reception status information.
19. The source base station according to claim 17, wherein the second
information acquiring unit comprises:
a request message transmitting unit configured to transmit a request message to
the user equipment indicating that the user equipment reports the reception status
information;
an information receiving unit configured to receive the reception status
information reported by the user equipment in response to the request message
transmitted by the request message transmitting unit, so as to acquire the reception
status information.
20. A computer-readable program, wherein when the program is executed in a

target base station, the program enables a computer to carry out the information
acquiring method as claimed in any of claims 1-6 in the target base station.
21. A storage medium in which a computer-readable program is stored, wherein
the computer-readable program enables a computer to carry out the information
acquiring method as claimed in any of claims 1-6 in a target base station.
22. A computer-readable program, wherein when the program is executed in a
source base station, the program enables a computer to carry out the information
acquiring method as claimed in any of claims 7-11 in the source base station.
23. A storage medium in which a computer-readable program is stored, wherein
the computer-readable program enables a computer to carry out the information
acquiring method as claimed in any of claims 7-11 in a source base station.