U.S. patent number 9,271,263 [Application Number 12/996,927] was granted by the patent office on 2016-02-23 for method of error recovery in transmitting and receiving voice service in packet based mobile communication systems.
The grantee listed for this patent is Jae Young Ahn, Soo Jung Jung, Jae Heung Kim, Kyoung Seok Lee. Invention is credited to Jae Young Ahn, Soo Jung Jung, Jae Heung Kim, Kyoung Seok Lee.
United States Patent |
9,271,263 |
Lee , et al. |
February 23, 2016 |
Method of error recovery in transmitting and receiving voice
service in packet based mobile communication systems
Abstract
Provided is a method of transmitting and receiving data using a
persistent allocation scheme in order to effectively support a
voice service between a base station and a mobile terminal in a
packet based mobile communication system. When an error occurs in
transmitting a control information that indicates whether to use a
radio resource using the persistent allocation scheme, the base
station may retransmit the control information and thereby maintain
a communication quality.
Inventors: |
Lee; Kyoung Seok (Daejeon,
KR), Kim; Jae Heung (Daejeon, KR), Jung;
Soo Jung (Daejeon, KR), Ahn; Jae Young (Daejeon,
KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Lee; Kyoung Seok
Kim; Jae Heung
Jung; Soo Jung
Ahn; Jae Young |
Daejeon
Daejeon
Daejeon
Daejeon |
N/A
N/A
N/A
N/A |
KR
KR
KR
KR |
|
|
Family
ID: |
41434556 |
Appl.
No.: |
12/996,927 |
Filed: |
June 17, 2009 |
PCT
Filed: |
June 17, 2009 |
PCT No.: |
PCT/KR2009/003254 |
371(c)(1),(2),(4) Date: |
December 08, 2010 |
PCT
Pub. No.: |
WO2009/154404 |
PCT
Pub. Date: |
December 23, 2009 |
Prior Publication Data
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|
|
|
Document
Identifier |
Publication Date |
|
US 20110188461 A1 |
Aug 4, 2011 |
|
Foreign Application Priority Data
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|
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Jun 20, 2008 [KR] |
|
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10-2008-0058425 |
Jun 15, 2009 [KR] |
|
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10-2009-0052760 |
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
72/0413 (20130101); H04W 72/04 (20130101); H04W
72/042 (20130101); H04L 1/0025 (20130101); H04L
1/1607 (20130101); H04L 1/0003 (20130101); H04W
72/1289 (20130101); H04L 1/1812 (20130101); H04W
88/08 (20130101); H04L 1/0009 (20130101) |
Current International
Class: |
H04W
72/04 (20090101); H04W 72/12 (20090101) |
Field of
Search: |
;370/328,329-330,335,336,337,252 ;455/450,452.1,452.2 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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|
|
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10-2007-0103649 |
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Oct 2007 |
|
KR |
|
Other References
Kalyanasundaram, Suresh et al., "Resource Allocation Scheme for
802.16," IEEE 802.16 Broadband Wireless Access Working Group,
http://ieee802.org/16, 3 pages, (2007). cited by applicant.
|
Primary Examiner: Elpenord; Candal
Claims
The invention claimed is:
1. A method of transmitting data in a base station, the method
comprising: transmitting a first part of the data and an activation
message indicating a start of a persistent scheduling transmission
in a same persistent allocation interval, the activation message
transmitted through a Physical Downlink Control Channel (PDCCH);
receiving an acknowledgement message for the activation message
from a terminal; transmitting a second part of the data according
to the persistent scheduling transmission; transmitting a
deactivation message indicating an end of the persistent scheduling
transmission; and receiving an acknowledgement message for the
deactivation message from the terminal, wherein the activation
message is retransmitted to the terminal if a negative
acknowledgement message for the activation message is received or a
positive acknowledgement message for the activation message is not
received from the terminal.
2. The method of claim 1, wherein the PDCCH including the
activation message is perceived by the terminal through
Semi-Persistent Scheduling Cell-Radio Network Temporary Identifier
(SPS C-RNTI).
3. The method of claim 1, wherein the first part of the data and
the second part of the data are transmitted through Physical
Downlink Shared Channel (PDSCH).
4. The method of claim 1, wherein the deactivation message is
transmitted through Physical Downlink Control Channel (PDCCH) and
the acknowledgement message for the deactivation message is
received through Physical Uplink Control Channel (PUCCH).
5. A method of receiving data in a terminal, the method comprising:
receiving a first part of the data and an activation message
indicating a start of a persistent scheduling transmission in a
same persistent allocation interval, the activation message
received through a Physical Downlink Control Channel (PDCCH);
transmitting an acknowledgement message for the activation message
to a base station; receiving a second part of the data according to
the persistent scheduling transmission; receiving a deactivation
message indicating an end of the persistent scheduling
transmission, the deactivation message received through the PDCCH;
and transmitting an acknowledgement message for the deactivation
message to the base station.
6. The method of claim 5, wherein the terminal perceives the PDCCH
including the activation message or the deactivation message using
Semi-Persistent Scheduling Cell-Radio Network Temporary Identifier
(SPS C-RNTI).
7. The method of claim 5, wherein the terminal transmits positive
acknowledgement message for the activation message successfully
received through PDCCH.
8. The method of claim 5, wherein the terminal transmits negative
acknowledgement message for the deactivation message included in
PDCCH if the terminal fails to decode the PDCCH.
Description
RELATED APPLICATIONS
This application is a 35 U.S.C. .sctn.371 national stage filing of
PCT Application No. PCT/KR2009/003254 filed on Jun. 17, 2009, which
claims priority to, and the benefit of, Korean Patent Application
No. 10-2008-0058425 filed on Jun. 20, 2008 and Korean Patent
Application No. 10-2009-0052760 filed on Jun. 15, 2009. The
contents of the aforementioned applications are hereby incorporated
by reference.
TECHNICAL FIELD
The present invention relates to a method of transmitting and
receiving data in a packet based mobile communication system, and
more particularly, to a method of re-covering from a reception
error of a control message, which occurs when transmitting and
receiving data using a persistent allocation scheme, in order to
effectively support a voice service between a base station and a
mobile terminal in a next generation packet mobile communication
system, which is under discussion for a standardization.
BACKGROUND ART
3.sup.rd Generation Partnership Project (3GPP), one of a number of
mobile communication standardization organizations, is engaging in
a Long Term Evolution (LTE) standardization process and an advanced
LTE standardization process in order to develop a packet based
mobile communication system standardization. A mobile communication
system generally includes a base station constituting a cell, and a
mobile terminal used by a user. A plurality of mobile terminals may
transmit and receive packet data to and from the base station via a
radio channel.
DISCLOSURE OF INVENTION
Technical Problem
An aspect of the present invention provides a method of effectively
controlling an activation and a deactivation of a persistent
allocation scheme when transmitting and receiving packet data using
the persistent allocation scheme, and a method of transmitting and
receiving a control message for an error recovery.
Technical Solution
According to an aspect of the present invention, there is provided
a base station including: a radio resource allocation unit to
allocate a radio resource to a terminal; a control information
generation unit to generate control information based on the
allocated radio resource; a transmitter to transmit the control
information to the terminal; and a receiver to receive an
acknowledgement (ACK) message with respect to the control
information.
According to another aspect of the present invention, there is
provided a terminal including: a receiver to receive, from a base
station, control information associated with data; and a
transmitter to transmit, to the base station, an ACK message with
respect to the control information. The receiver may receive the
data based on the control information.
According to still another aspect of the present invention, there
is provided a base station including: a transmitter to transmit, to
a terminal, control information associated with first data, and to
transmit the first data to the terminal using the control
information; and a receiver to receive an ACK message with respect
to the control information. When the ACK message with respect to
the control information is not received, the transmitter may
retransmit the control information.
Advantageous Effects
According to embodiments of the present invention, when an error
occurs wherein the error is an activation message not received by a
terminal transmitted from a base station in a persistent allocation
scheme, it is possible to quickly recover from the error.
BRIEF DESCRIPTION OF DRAWINGS
FIG. 1 is a diagram illustrating an example of recovering from a
transmission error according to an embodiment of the present
invention;
FIG. 2 is a diagram illustrating an operation of a base station
recovering from a transmission error according to an embodiment of
the present invention;
FIG. 3 is a diagram illustrating an operation of a terminal
recovering from a transmission error according to an embodiment of
the present invention;
FIG. 4 is a block diagram illustrating a structure of a base
station according to an embodiment of the present invention;
FIG. 5 is a block diagram illustrating a structure of a terminal
according to an embodiment of the present invention; and
FIG. 6 is a block diagram illustrating a structure of a base
station according to another embodiment of the present
invention.
MODE FOR THE INVENTION
Reference will now be made in detail to exemplary embodiments of
the present invention, examples of which are illustrated in the
accompanying drawings, wherein like reference numerals refer to the
like elements throughout. Exemplary embodiments are described below
to explain the present invention by referring to the figures.
FIG. 1 is a diagram illustrating an example of recovering from a
transmission error according to an embodiment of the present
invention. Although FIG. 1 shows an embodiment where a base station
transmits downlink data to a terminal, the present invention may be
applicable to an embodiment where the terminal transmits uplink
data to the base station.
Generally, an amount of the downlink data may be too great to be
transmitted from the base station to the terminal at once.
Therefore, the base station may divide the downlink data into a
plurality of data blocks, and sequentially transmit the divided
data blocks to the terminal. Hereinafter, the divided data blocks
are referred to as first data, second data, and the like,
respectively.
Referring to FIG. 1, the base station may transmit first data 120
to the terminal. The base station may transmit control information
110 associated with the first data 120 prior to transmitting the
first data 120. According to an embodiment of the present
invention, the control information 110 may include information
associated with a radio resource used to transmit the first data
120. The terminal may receive information associated with the radio
resource, and receive the first data 120 by referring to the
received information associated with the radio resource. For
example, the terminal may be aware of information associated with a
time domain or a frequency domain where the first data 120 is
transmitted, by referring to information associated with the radio
resource. The terminal may receive the first data 120 in the time
domain or the frequency domain where the first data 120 is
transmitted.
The control information 110 may include modulation and coding
scheme information associated with the first data 120 or error
control scheme information associated with the first data 120. The
terminal may receive the modulation and coding scheme information
or the error control scheme information, and receive the first data
120 using the modulation and coding scheme information or the error
control scheme information.
When the present invention is applied to a 3.sup.rd Generation
Partnership Project (3GPP) Long Term Evolution (LTE) system,
control information may be transmitted using a Physical Downlink
Control Channel (PDCCH). Also, first data or second data may be
transmitted using a Physical Downlink Shared Channel (PDSCH).
Referring again to FIG. 1, the base station may transmit data every
persistent allocation interval 190. After transmitting the first
data 120, the base station may transmit second data 140 to the
terminal. When control information 130 associated with the second
data 140 is different from the control information 110 associated
with the first data 120, the base station may transmit the control
information 130 associated with the second data 140 to the
terminal.
The terminal may receive information associated with a radio
resource to transmit the second data 140, and modulation and coding
scheme information or error control scheme information associated
with the second data 140, which are included in the control
information 130. The terminal may receive the second data 140 using
the control information 130.
A case where the control information 110 associated with the first
data 120 is different from the control information 130 associated
with the second data 140 is referred to as a variable allocation
scheme. The variable allocation scheme may need to transmit control
information with respect to every piece of data.
In the case of a service with a low data transmission rate such as
a voice service, when control information is additionally
transmitted with respect to every piece of data, it may be
ineffective. The base station may apply the same modulation and
coding scheme or the same error control scheme to every piece of
data. In this case, the control information 110 associated with the
first data 120 may be the same as the control information 130
associated with the second data 140. Accordingly, only when
initially transmitting data, the base station may transmit the
control information 110. After transmitting the control information
110, the base station may not transmit additional control
information. Since a transmission of control information decreases,
a radio resource utilization efficiency may be enhanced, which is
referred to as a persistent allocation scheme or a semi-persistent
scheduling scheme.
In the case of the persistent allocation scheme, an activation
message included in the control information 110 may be transmitted
prior to data transmission. The activation message indicates a
start of use of the radio resource. Also, a deactivation message
included in control information 170 may be transmitted after the
data transmission. The deactivation message indicates a suspension
of use of the radio resource.
Since a status of a radio channel formed between the base station
and the terminal may be unstable, the terminal may not receive
control information. When the terminal does not receive the control
information, the terminal may not receive first data and second
data.
Referring to FIG. 1, in the variable allocation scheme, the control
information 110, 130, and 150 may be transmitted with respect the
first data 120, the second data 140, and third data 160,
respectively. Therefore, when the terminal does not receive the
control information 110 associated with the first data 120, the
terminal may abandon receiving of the first data 120. When the
terminal receives the control information 130 associated with the
second data 140, the terminal may receive the second data 140 using
the control information 130.
In the persistent allocation scheme, the control information 110
and 130 may be transmitted at particular points in time. When the
terminal does not receive the control information 110 and 130, the
terminal may not receive the first data 120 and the second data
140.
According to an embodiment of the present invention, when a
terminal receives a control information, the terminal may transmit,
to a base station, an acknowledgement (ACK) message with respect to
the control information. When the base station receives, from the
terminal, the ACK message with respect to the control information,
it may be known that the base station successfully receives the
control information.
Conversely, when the base station does not receive the ACK message
with respect to the control information, whether the terminal
successfully receives the control information may be uncertain. In
preparation for a case where the terminal does not receive the
control information, the base station may retransmit the control
information to the terminal.
FIG. 2 is a diagram illustrating an operation of a base station
recovering from a transmission error according to an embodiment of
the present invention. The base station may transmit first data 242
and 252, second data 262, and control information 241, 251, and 261
using a downlink channel 210.
The control information 241 may include an activation message with
respect to a radio resource. The terminal may receive the first
data 242 using the radio resource. The transmission error may be
defined as the control information 241 or the first data 242
transmitted from the base station is not received by the
terminal.
When the transmission error occurs, the terminal may not recognize
that the radio resource is activated. Also, since the terminal may
be unaware of that the control information 241 or the first data
242 is transmitted, the terminal may not transmit a NACK message
243.
When the base station does not receive an ACK message from the
terminal, the base station may retransmit the first data 252. Also,
the base station may retransmit the control information 251
associated with the first data 252. The retransmitted control
information 251 may include an activation message with respect to
the radio resource, and modulation and coding scheme information or
error control scheme information associated with the first data
252.
When the terminal receives the retransmitted control information
251 and transmits an ACK message 253 to the base station using an
uplink channel 220, the base station may no longer transmit
additional control information. The base station may transmit the
second data 262 to the terminal but may not transmit control
information 261 associated with the second data 262. The terminal
may receive the second data 262 using the control information 251
with respect to the second data 262.
When the terminal does not receive, from the base station, a
deactivation message with respect to a radio resource, the base
station may retransmit the deactivation message to the terminal,
which is similar to an embodiment of checking on ACK message and
retransmitting an activation message with respect to the radio
resource.
FIG. 3 is a diagram illustrating an operation of a terminal
recovering from a transmission error according to an embodiment of
the present invention. A base station may transmit first data 342
and 352, and second data 362 using a downlink channel 310. Also,
the base station may transmit control information 341, 351, and 361
using the downlink channel 310.
Here, it is assumed that the base station transmits the control
information 341 associated with the first data 342 but a
transmission error occurs.
When the transmission error occurs, the terminal may not receive an
ACK message and may not transmit a NACK message 343. When the base
station does not receive the ACK message from the terminal, the
base station may retransmit the first data 352. The retransmitted
control information 351 may include modulation and coding scheme
information or error control scheme information associated with the
first data 352.
The terminal may receive the first data 352 using the retransmitted
control information 351. An activation message with respect to a
radio resource may not be received yet at the terminal. The
terminal may retransmit an error recovery request 354 using an
uplink channel 320.
The base station may retransmit an activation message 361, in
response to the error recovery request 354.
When the terminal does not receive, from the base station, a
deactivation message with respect to a radio message, the base
station may retransmit the deactivation message to the terminal,
which is similar to an embodiment of retransmitting an activation
message with respect to the radio resource.
FIG. 4 is a block diagram illustrating a structure of a base
station 400 according to an embodiment of the present invention.
The base station 400 may include a radio resource allocation unit
410, a control information generation unit 420, a transmitter 430,
and a receiver 440.
The radio resource allocation unit 410 may allocate a radio
resource to a terminal 450.
The control information generation unit 420 may generate control
information by referring to the allocated radio resource. The
control information may include information associated with the
radio resource.
The transmitter 430 may transmit the control information to the
terminal 450. According to an embodiment of the present invention,
the transmitter 430 may transmit first data to the terminal 450
using the radio resource. The terminal 450 may receive information
associated with the radio resource, included in the control
information, and receive the first data using information
associated with the radio resource.
According to an embodiment of the present invention, control
information may include an activation message or a deactivation
message with respect to a radio resource. The activation message
with respect to the radio resource indicates that a previously
unused radio resource is allocated to a particular terminal and is
used to transmit first data. The deactivation message with respect
to the radio resource indicates that a radio resource used to
transmit the first data is released. In a 3GPP LTE system, the
activation message and the deactivation message may be indicated as
a field of a PDCCH, for example, one bit, or may be indicated as a
terminal identifier for a voice service, for example, a
semi-persistent scheduling C-RNTI, and the like.
Accordingly, the terminal 450 may receive the activation message
with respect to the radio resource, and transmit the first data
using the radio resource associated with the activation message.
The terminal 450 may receive the deactivation message with respect
to the radio resource and may suspend a transmission of the first
data using the radio resource.
When the terminal 450 does not receive the activation message with
respect to the radio resource, the terminal 450 may not receive the
first data. Also, when the terminal 450 does not receive the
deactivation message with respect to the radio resource, the radio
resource may not be retrieved. Accordingly, the base station 400
may need to verify whether the terminal 450 receives the activation
message or the deactivation message with respect to the radio
resource. The terminal 450 may receive the control information, and
may transmit, to the base station 400, an ACK message with respect
to the received control information.
The receiver 440 may receive the ACK message with respect to the
control information. When the receiver 440 does not receive the ACK
message with respect to the control information, the base station
400 may not verify whether the terminal 450 does not receive the
control information. In this case, the transmitter 430 may
retransmit the control information to the terminal 450.
When the present invention is applied to the 3GPP LTE system, the
ACK message may be transmitted using a Physical Uplink Control
Channel (PUCCH). A content of the ACK message may include a Hybrid
ARQ Positive Acknowledgement (HARQ ACK). A content of a NACK
message may include a HARQ NACK.
According to an embodiment of the present invention, the control
information may include modulation and coding scheme information
associated with the first data or error control scheme information
associated with the first data.
The transmitter 430 may transmit, to the terminal 450, the
modulation and coding scheme information or the error control
scheme information associated with the first terminal. The terminal
450 may receive the first data based on the modulation and coding
scheme information or the error control scheme information.
According to an embodiment of the present invention, the
transmitter 430 may transmit, to the terminal 450, second data
using modulation and coding scheme information associated with the
first data or error control scheme information associated with the
first data. Specifically, control information transmitted from the
transmitter 430 may be applicable to a plurality of data as well as
particular data.
Also, the transmitter 430 may transmit the first data or the second
data using the radio resource associated with the activation
message.
FIG. 5 is a block diagram illustrating a structure of a terminal
500 according to an embodiment of the present invention. The
terminal 500 may include a receiver 510 and a transmitter 520.
The receiver 510 may receive, from a base station 530, control
information associated with data.
When the receiver 510 successfully receives the control
information, the transmitter 520 may transmit, to the base station
530, an ACK message with respect to the control information.
According to an embodiment of the present invention, the control
information may include information regarding a radio resource
associated with first data. The receiver 510 may receive the first
data by referring to information associated with the radio
resource.
According to an embodiment of the present invention, the control
information may include modulation and coding scheme information
associated with the first data or error control scheme information
associated with the first data.
According to an embodiment of the present invention, the control
information may include an activation message or a deactivation
message with respect to the radio resource. The activation message
with respect to the radio resource indicates that a previously
unused radio resource is allocated to a particular terminal and is
used to transmit the first data. The deactivation message with
respect to the radio resource indicates that the radio resource
used to transmit the first data is released. The receiver 510 may
receive the first data using the activated radio resource.
FIG. 6 is a block diagram illustrating a structure of a base
station 600 according to another embodiment of the present
invention. The terminal 600 may include a transmitter 610 and a
receiver 620.
The transmitter 610 may transmit, to a terminal 630, control
information associated with first data. According to an embodiment
of the present invention, the control information may include
information associated with a radio resource that is allocated for
the first data. Specifically, the control information may include
information associated with a time domain or a frequency domain
where the first data is transmitted.
According to an embodiment of the present invention, the control
information may include an activation message with respect to the
radio resource. The activation message with respect to the radio
resource indicates that a previously unused radio resource is
allocated to a particular terminal and is used to transmit the
first data. The terminal 630 may receive the activation message and
receive the first data using the activated radio resource.
Also, the deactivation message with respect to the radio resource
indicates that the radio resource used to transmit the first data
is released. The terminal 630 may receive the deactivation message
and suspend the data transmission using the radio resource.
The control information may include at least one of modulation and
coding scheme information associated with the first data and error
control scheme information associated with the first data. The
terminal 630 may receive the first data using the modulation and
coding scheme information or the error control scheme
information.
The control information is required for the terminal 630 to receive
the first data. Accordingly, the base station 600 may verify
whether the terminal 630 receives the control information.
According to an embodiment of the preset invention, when the
terminal 630 receives the control information, the terminal 630 may
transmit, to the base station 600, an ACK message with respect to
the control information. The receiver 620 may receive the ACK
message with respect to the control information.
When the receiver 620 does not receive the ACK message with respect
to the control information, it is uncertain whether the terminal
630 receives the control information. Accordingly, the transmitter
610 may retransmit the control information to the terminal 630.
According to an embodiment of the present invention, the control
information may be applicable to second data as well as the first
data. In this case, the transmitter 610 may also transmit the
second data using the control information.
Although a few exemplary embodiments of the present invention have
been shown and described, the present invention is not limited to
the described exemplary embodiments. Instead, it would be
appreciated by those skilled in the art that changes may be made to
these exemplary embodiments without departing from the principles
and spirit of the invention, the scope of which is defined by the
claims and their equivalents.
* * * * *
References