U.S. patent number RE48,969 [Application Number 15/229,082] was granted by the patent office on 2022-03-08 for apparatus and method for random access in cellular system.
This patent grant is currently assigned to Electronics and Telecommunications Research Institute. The grantee listed for this patent is Electronics and Telecommunications Research Institute. Invention is credited to Seung Chan Bang, Jae Heung Kim, Jung-Im Kim, Kyoung Seok Lee, Byung-Han Ryu.
United States Patent |
RE48,969 |
Kim , et al. |
March 8, 2022 |
Apparatus and method for random access in cellular system
Abstract
Disclosed is a method and apparatus for RA in a cellular system.
The RA in the cellular system includes receiving an RA preamble
from a terminal for RA, transmitting, to the terminal, an RA
response message including a sequence of the received RA preamble
and uplink resource information of the terminal and overload state
information with respect to the RA, receiving control information
generated based on the RA response message from the terminal
through the uplink resource information, and transmitting control
response information with respect to the received control
information.
Inventors: |
Kim; Jae Heung (Daejeon,
KR), Lee; Kyoung Seok (Daejeon, KR), Kim;
Jung-Im (Daejeon, KR), Ryu; Byung-Han (Daejeon,
KR), Bang; Seung Chan (Daejeon, KR) |
Applicant: |
Name |
City |
State |
Country |
Type |
Electronics and Telecommunications Research Institute |
Daejeon |
N/A |
KR |
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Assignee: |
Electronics and Telecommunications
Research Institute (Daejeon-si, KR)
|
Family
ID: |
40901288 |
Appl.
No.: |
15/229,082 |
Filed: |
August 4, 2016 |
PCT
Filed: |
December 31, 2008 |
PCT No.: |
PCT/KR2008/007822 |
371(c)(1),(2),(4) Date: |
July 23, 2010 |
PCT
Pub. No.: |
WO2009/093816 |
PCT
Pub. Date: |
July 30, 2009 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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Reissue of: |
12864389 |
Dec 31, 2008 |
8797973 |
Aug 5, 2014 |
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Foreign Application Priority Data
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Jan 23, 2008 [KR] |
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10-2008-0007134 |
Jun 27, 2008 [KR] |
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10-2008-0061646 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H04W
74/002 (20130101); H04W 48/16 (20130101); H04W
84/042 (20130101); H04W 74/08 (20130101); H04W
48/06 (20130101) |
Current International
Class: |
H04W
74/00 (20090101); H04W 74/08 (20090101); H04W
84/04 (20090101); H04W 48/16 (20090101); H04W
48/06 (20090101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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2003-506931 |
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Feb 2003 |
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JP |
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2006-501769 |
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Jan 2006 |
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JP |
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2006-67115 |
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Mar 2006 |
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JP |
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07/001222 |
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Jan 2007 |
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WO |
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07/024791 |
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Mar 2007 |
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WO |
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07/024791 |
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Mar 2007 |
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WO |
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07/078165 |
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Jul 2007 |
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WO |
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07/083230 |
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Jul 2007 |
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WO |
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07/091810 |
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Aug 2007 |
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WO |
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07/091831 |
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Aug 2007 |
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WO |
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07/091831 |
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Aug 2007 |
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WO |
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Primary Examiner: Craver; Charles R
Claims
The invention claimed is:
1. A .Iadd.communication.Iaddend.method.[.for Random Access (RA) in
a communication system.]., the method comprising:
receiving.[.RA.]..Iadd., at a base station, Random Access (RA)
.Iaddend.preambles from a plurality of terminals; .[.and.].
.Iadd.generating, at the base station, an RA response message; and
.Iaddend. transmitting.[.an.]..Iadd., at the base station, the
.Iaddend.RA response message.[.to the plurality of terminals.].,
wherein the RA response message includes: common information for
the plurality of terminals.Iadd., .Iaddend.wherein the common
information comprises overload condition information.[.with respect
to the RA of the plurality of terminals.].; a plurality of RA
preamble indicators.[.respectively indicating each RA preamble from
each terminal.].; and a plurality of RA responses.[.respectively
corresponding to each terminal.]., wherein the common information
.[.including.]. .Iadd.comprising .Iaddend.the overload condition
information in the RA response message is distinct from the
plurality of RA preamble indicators and the plurality of RA
responses, and the RA response message further includes an
information discrimination field indicating that the overload
condition information is included.[.;.]..Iadd., and
.Iaddend.wherein the overload condition information .[.includes.].
.Iadd.comprises .Iaddend.a back off time information.[.for the
plurality of the terminals.]..
2. The method of claim 1, wherein each .Iadd.of the plurality of
.Iaddend.RA .[.response.]. .Iadd.responses .Iaddend.comprises
uplink timing information.[.,.]. .Iadd.and .Iaddend.uplink
allocation information.[., and temporary terminal
identifier.]..
3. The method of claim 2, wherein the uplink allocation information
indicates uplink resource to be used on .[.the.]. uplink
transmission and further indicates modulation and coding scheme for
the uplink resource.
.[.4. The method of claim 1, wherein the RA response message
includes: the common information comprising the overload condition
information; first RA preamble indicator corresponding to a first
terminal among the terminals; second RA preamble indicator
corresponding to a second terminal among the terminals; first RA
response corresponding to the first terminal; and second RA
response corresponding to the second terminal..].
.[.5. The method of claim 4, wherein the first RA response
comprises first uplink timing information, first uplink allocation
information, and first temporary terminal identifier corresponding
to the first terminal and the second RA response comprises second
uplink timing information, second uplink allocation information,
and second temporary terminal identifier corresponding to the
second terminal..].
.[.6. The method of claim 1, wherein the RA response message
further includes preamble existence field indicating if additional
RA preamble indicator exists or not..].
7. A .Iadd.communication .Iaddend.method.[.for Random Access (RA)
of a first terminal in a communication system.]., the method
comprising: transmitting.[.an RA.]..Iadd., at a first terminal, a
Random Access (RA) .Iaddend.preamble to a base station; and
receiving.Iadd., at the first terminal, .Iaddend.an RA response
message from the base station, wherein the RA response message
includes: common information for the first terminal and second
terminals.[.attempting RA to the base station.]..Iadd.,
.Iaddend.wherein the common information comprises overload
condition information.[.with respect to the RA of the first
terminal and the second terminals.].; .[.first RA preamble
indicator corresponding to the first terminal; .]. a plurality of
RA preamble indicators.[.respectively corresponding to the second
terminals.].; .[.first RA response corresponding to the first
terminal;.]. and a plurality of RA responses.[.respectively
corresponding to the second terminals.]., wherein the common
information .[.including.]. .Iadd.comprising .Iaddend.the overload
condition information in the RA response message is distinct from
the plurality of RA preamble indicators and the plurality of RA
responses, and the RA response message further includes an
information discrimination field indicating that the overload
condition information is included.[.;.]..Iadd., and
.Iaddend.wherein the overload condition information .[.includes.].
.Iadd.comprises .Iaddend.a back off time information.[.for the
first terminal and the second terminals.]..
8. The method of claim 7, wherein .Iadd.each of .Iaddend.the
.[.first.]. .Iadd.plurality of .Iaddend.RA .[.response.].
.Iadd.responses .Iaddend.comprises uplink timing information.[.,.].
.Iadd.and .Iaddend.uplink allocation information.[., and temporary
terminal identifier for the first terminal.]..
9. The method of claim 8, wherein the uplink allocation information
indicates uplink resource to be used on .[.the.]. uplink
transmission and further indicates modulation and coding scheme for
the uplink resource.
.Iadd.10. A communication apparatus, comprising: a memory; and a
processor, operably coupled to the memory, wherein the processor,
when executing program instructions stored in the memory, is
configured to: cause the communication apparatus to receive Random
Access (RA) preambles from a plurality of terminals; generate an RA
response message; and transmit the RA response message, wherein the
RA response message includes: common information for the plurality
of terminals, wherein the common information comprises overload
condition information; a plurality of RA preamble indicators; and a
plurality of RA responses, wherein the common information
comprising the overload condition information in the RA response
message is distinct from the plurality of RA preamble indicators
and the plurality of RA responses, and the RA response message
further includes an information discrimination field indicating
that the overload condition information is included, and wherein
the overload condition information comprises a back off time
information..Iaddend.
.Iadd.11. The communication apparatus of claim 10, wherein each of
the plurality of RA responses comprises uplink timing information
and uplink allocation information..Iaddend.
.Iadd.12. The communication apparatus of claim 11, wherein the
uplink allocation information indicates uplink resource to be used
on uplink transmission and further indicates modulation and coding
scheme for the uplink resource..Iaddend.
.Iadd.13. A terminal, comprising: a memory; and a processor
operably coupled to the memory, wherein the processor, when
executing program instructions stored in the memory, is configured
to: cause the terminal to transmit a Random Access (RA) preamble to
a base station; and cause the terminal to receive an RA response
message from the base station, wherein the RA response message
includes: common information for the terminal and second terminals,
wherein the common information comprises overload condition
information; a plurality of RA preamble indicators; and a plurality
of RA responses, wherein the common information comprising the
overload condition information in the RA response message is
distinct from the plurality of RA preamble indicators and the
plurality of RA responses, and the RA response message further
includes an information discrimination field indicating that the
overload condition information is included, and wherein the
overload condition information comprises a back off time
information..Iaddend.
.Iadd.14. The terminal of claim 13, wherein each of the plurality
of RA responses comprises uplink timing information and uplink
allocation information..Iaddend.
.Iadd.15. The terminal of claim 14, wherein the uplink allocation
information indicates uplink resource to be used on uplink
transmission and further indicates modulation and coding scheme for
the uplink resource..Iaddend.
.Iadd.16. A communication device for a terminal, comprising: a
memory; and a processor operably coupled to the memory, wherein the
processor, when executing program instructions stored in the
memory, is configured to: cause the terminal to transmit a Random
Access (RA) preamble to a base station; and cause the terminal to
receive an RA response message from the base station, wherein the
RA response message includes: common information for the terminal
and second terminals, wherein the common information comprises
overload condition information; a plurality of RA preamble
indicators; and a plurality of RA responses, wherein the common
information comprising the overload condition information in the RA
response message is distinct from the plurality of RA preamble
indicators and the plurality of RA responses, and the RA response
message further includes an information discrimination field
indicating that the overload condition information is included, and
wherein the overload condition information comprises a back off
time information..Iaddend.
.Iadd.17. The communication device of claim 16, wherein each of the
plurality of RA responses comprises uplink timing information and
uplink allocation information..Iaddend.
.Iadd.18. The communication device of claim 17, wherein the uplink
allocation information indicates uplink resource to be used on
uplink transmission and further indicates modulation and coding
scheme for the uplink resource..Iaddend.
Description
RELATED APPLICATIONS
This application .Iadd.is a reissue application of U.S. Pat. No.
8,797,973 issued Aug. 5, 2014, which is issued from U.S. patent
application Ser. No. 12/864,389, filed on Jul. 23, 2010, which
.Iaddend.is a 35 U.S.C. .sctn.371 national stage filing of PCT
Application No. PCT/KR2008/007822 filed on Dec. 31, 2008, which
claims priority to, and the benefit of, Korean Patent Application
No. 10-2008-0007134 filed on Jan. 23, 2008 and Korean Patent
Application No. 10-2008-0061646 filed on Jun. 27, 2008. The
contents of the aforementioned applications are hereby incorporated
by reference.
TECHNICAL FIELD
The present invention relates to a method and apparatus for Random
Access (RA) in a cellular system, and particularly, to a method and
apparatus for RA using RA response message including common
information.
BACKGROUND ART
In a cellular system for packet service, a plurality of terminals
share radio resources unlike a circuit system where resources are
allocated only to one terminal.
Accordingly, notification of the fact that radio resources are
allocated to each terminal in the cellular system is required to be
performed through AC response information so that each terminal can
discriminate and access to the radio resources. In this instance,
the cellular system is required to possess and transmit using
minimal radio resources, thereby maximizing application of limited
radio resources, when transmitting RA response information. Also,
the RA response information is required to have a format for
improving operational efficiency of a terminal that receives the RA
response information.
DISCLOSURE OF INVENTION
Technical Problem
An aspect of the present invention provides a method and apparatus
for Random Access (RA) which can improve operational efficiency of
a terminal using an RA response message in byte alignment in a
cellular system.
Another aspect of the present invention also provides a method and
apparatus for RA which can efficiently use radio resources using
existing RA preamble index in the cellular system.
Technical Solution
According to an aspect of the present invention, there is provided
a method for Random Access (RA) in a cellular system, the method
including: receiving an RA preamble from a terminal for RA,
transmitting, to the terminal, an RA response message including a
sequence of the received RA preamble and uplink resource
information of the terminal and overload state information with
respect to the RA, receiving control information, generated based
on the RA response message, from the terminal through the uplink
resource information, and transmitting control response information
with respect to the received control information.
According to another aspect of the present invention, there is
provided a terminal in a cellular system, including: a preamble
transmitter to randomly select one of sequences preset by a base
station, and to transmit an RA preamble, an RA response message
processor to receive an RA response message including the RA
preamble sequence and overload state information with respect to
the RA from the base station, and to extract response information
corresponding to the RA preamble sequence from the received RA
response message, and a control information transmitter to generate
radio resource control information based on the extracted response
information, and to transmit the radio resource control
information.
According to another aspect of the present invention, there is
provided a base station in a cellular system, including: a preamble
response information generator to receive RA preamble from a
terminal, and to generate a response corresponding to the RA
preamble, an RA response message generator to generate an RA
response message including overload state information with respect
to RA, sequence of the received RA preamble, and the generated
response information, and a control response transmitter to receive
radio resource control information generated based on the RA
response message, and to transmit control response information with
respect to the radio resource control information.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1 is a block diagram illustrating a configuration of a
cellular system according to example embodiments of the present
invention;
FIG. 2 is an example of a format of a basic response message which
constitutes a Random Access (RA) response message according to
example embodiments of the present invention;
FIG. 3 illustrates a format of an RA response message according to
a first example embodiment of the present invention;
FIG. 4 illustrates a format of an RA response message according to
a second example embodiment of the present invention;
FIG. 5 illustrates a format of an RA response message according to
a third example embodiment of the present invention;
FIG. 6 illustrates a format of an RA response message according to
a fourth example embodiment of the present invention; and
FIG. 7 illustrates an RA procedure of the cellular system according
to example embodiments of the present invention.
MODE FOR THE INVENTION
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, wherein like reference
numerals refer to the like elements throughout.
Hereinafter, a method and apparatus for efficiently constituting a
Random Access (RA) response message in a cellular system according
to example embodiments of the present invention will be described
in detail referring to attached drawings.
A plurality of terminals share radio resources in the cellular
system unlike a circuit system where resources are allocated only
to one terminal.
Accordingly, it is required to be notified through an AC response
information that radio resources are allocated to each terminal in
the cellular system so that each terminal can discriminate and
access to the radio resource.
In this instance, the RA procedure in the cellular system may be
classified into a contention scheme and a non-contention
scheme.
The RA procedure of the contention scheme is a RA procedure
performed by a terminal to which a Cell Radio Network Temporary
Identifier (C-RNTI) is not yet allocated from a base station or by
a terminal to which a RA preamble sequence for the RA procedure is
not allocated even though the C-RNTI is already allocated.
Conversely, the RA procedure of the non-contention scheme is a RA
procedure that a base station allocates an RA preamble sequence
which a terminal initially transmits in order for the RA procedure,
and thereby can avoid competition which may occur in the RA
procedure. The non-contention scheme may be targeted for a terminal
in a handover or a terminal that is required to restart downlink
data transmission.
FIG. 1 is a block diagram illustrating a configuration of a
cellular system according to example embodiments of the present
invention.
Referring to FIG. 1, the cellular system includes a terminal 100
and a base station 200.
The terminal 100 may include a preamble transmitter 110, RA
response message processor 120, and control information transmitter
130.
The preamble transmitter 110 randomly select one of sequences
preset by the base station 200 and transmit an RA preamble.
The RA response message processor 120 may receive an RA response
message from the base station 200 and process the same.
Here, the RA response message may be in byte alignment and include
common information, a detecting preamble index indicator, and
response information.
The common information may include RA overload state
information.
The detecting preamble index indicator may include RA preamble
indexes of a plurality of terminals that attempt RA and also
include response information corresponding to each of the RA
preamble indexes.
Specifically, the response information may include uplink
transmission timing alignment information, uplink transmission
power correction information, uplink radio resource allocation
information, temporarily allocated terminal identifier, and the
like.
The RA response message processor 120 may verify whether an RA
preamble sequence transmitted from the transmitter 110 is identical
to an RA preamble index of the detecting preamble index indicator.
In this instance, the RA response message processor 120 verify with
respect to all of the plurality of RA preamble indexes included in
the detecting preamble index indicator. When the identical RA
preamble index exists, the RA response message processor 120 may
extract response information corresponding to the RA preamble
index.
The control information transmitter 130 may transmit control
information including Radio Resource Control (RRC) connection and
the like using the response information extracted from the response
message processor 120. That is, the control information transmitter
130 may transmit control information formed by a power and
modulation method corresponding to the response information through
uplink resource information.
The base station 200 includes a preamble response information
generator 210, RA response message generator 220, and control
response transmitter 230.
The preamble response information generator 210 may receive an RA
preamble from the terminal 100 and generate response information
corresponding to the received RA preamble. That is, the preamble
response information generator 210 may temporarily allocate a
terminal identifier to discriminate a terminal that attempts RA and
align uplink transmission time of the terminal 100. The preamble
response information generator 210 may determine power with respect
to information that the terminal may transmit later based on power
information of the RA preamble. Also, the preamble response
information generator 210 may allocate uplink information through
which the terminal may transmit control information. Finally, the
preamble response information generator 210 may generate response
information including a terminal identifier that is temporarily
allocated to the terminal where the RA preamble is transmitted,
uplink transmission time, and power and uplink information.
The RA response message generator 220 may generate an RA response
message including common information, detecting preamble index
indicator, and response information, and transmit the generated RA
response through a single downlink. Specifically, the RA response
message generator 220 may generate the common information including
overload state information due to random access and receive RA
preamble index and response information from the preamble response
information generator 210, and thereby can form the RA response
message. In this instance, the RA response message generator 220
may include every detecting preamble index indicator and response
information corresponding to a plurality of terminals.
FIG. 2 is an example of a format of a basic response message which
constitutes an RA response message according to example embodiments
of the present invention.
Referring to FIG. 2, the basic response message constituting the RA
response message is in byte alignment, and thereby can improve
operational efficiency of a terminal that receives a message.
The basic response message constituting the RA response message may
include a preamble existence bit 3, RA preamble index 5, uplink
transmission timing alignment information 6, uplink transmission
power correction information 7, uplink radio resource allocation
information 8, and temporarily allocated terminal identifier 9.
The RA preamble index 5 may be an index indicating an RA preamble
sequence received from the terminal for the RA. The RA preamble
index 5, for example, may be composed of six bits.
The preamble existence bit 3 indicates an RA preamble index for an
additional terminal excluding the terminal to which the RA preamble
index 5 is transmitted exists. For example, when the preamble
existence bit 3 is set to one, it may indicate that there is the
additional RA preamble index and when set to zero, it may indicate
that there is no other RA preamble index.
The uplink transmission timing alignment information 6 is
information for aligning uplink transmission time of the terminal
to which the RA preamble index 5 is transmitted. The uplink
transmission timing alignment information 6, for example, may be
composed of eight to eleven bits.
The uplink transmission power correction information 7 indicates
transmission power correction information of the terminal to which
the RA preamble index 5 is transmitted. That is, the uplink
transmission power correction information 7 indicates uplink
transmission power correction information to be applied to a
transmission timing of control information that the terminal may
transmit subsequently, based on RA preamble reception power. The
uplink transmission power alignment information 7, for example, may
be composed of five to twenty four bits.
The uplink radio resource allocation information 8 indicates uplink
radio resource information that enables the terminal that attempts
RA to transmit control information to an uplink after receiving the
RA response message. The uplink radio resource allocation
information 8 may include radio resource allocation information
including location information of a sub-carrier which the terminal
is able to possess and modulation and encoding information to be
applied when the terminal transmits data through allocated radio
resources.
The temporarily allocated terminal identifier 9 indicates an
identifier that is temporarily allocated for discrimination of the
terminal that attempts the RA in order to perform scheduling in a
base station. The temporarily allocated terminal identifier 9, for
example, may be composed of sixteen bits.
Also, a reserved field 4 included in the detecting preamble index
indicator 13 indicates a reserved bit. The reserved field 4 may be
used as an information discrimination bit which indicates one byte
information including the reserved field 4 is common information or
uncommon information.
FIG. 3 illustrates a format of an RA response message according to
a first example embodiment of the present invention.
Referring to FIG. 3, the RA response message according to the first
example embodiment of the present invention may include common
information 12, detecting preamble index indicator 13,
non-contention response message 14, and contention response message
15. The common information 12, detecting preamble index indicator
13, non-contention response message 14, and contention response
message 15 included in the RA response message may be in byte
alignment, and may be multiplexed to a single shared downlink
channel and transmitted to a terminal.
The common information 12 may include a preamble existence bit 3,
information distribution bit 4a, number of non-contention response
information 1, and RA overload state 2. The common information 12
may be composed of one byte.
The preamble existence bit 3 indicates an RA preamble index 5 that
is received from a terminal that attempts RA next to a common
information.
Accordingly, the preamble existence bit 3 included in the common
information 12 may indicate response messages 14 and 15 or the
detecting preamble index indicator 13 which may exist next to the
common information 12.
The information discrimination bit 4a may help discriminate whether
the information including the information discrimination bit 4a is
the common information 12 or RA information excluding the common
information 12, namely, uncommon information.
For example, when the information discrimination bit 4a is set to
one, the information of one byte including the information
discrimination bit 4a may indicate the common information 12.
The number of non-contention response information 1, which
indicates a number of non-contention response information 11, may
enable the terminal to discriminate the non-contention response
message 14 from the contention response message 15.
The RA overload state 2, which indicates an overload state by RA,
may provide information to help the terminal to avoid a possibility
of collision on random access. For example, the RA overload state 2
indicates information such as a back off process of the terminal or
a number of RA attempts, selecting an RA preamble, and the
like.
The detecting preamble index indicator 13 may include the RA
preamble index 5, preamble existence bit 3, and information
discrimination bit 4a.
The RA preamble index 5 may indicate an RA preamble sequence
received from the terminal that attempts RA.
The preamble existence bit 3 may indicate an RA preamble index of
another terminal that attempts RA.
The information discrimination bit 4a may help discriminate whether
the information including the information discrimination bit 4a is
the common information 12 or RA information excluding the common
information 12, namely, uncommon information.
For example, when the information discrimination bit 4a is set to
zero, the information of one byte including the information
discrimination bit 4a may indicate the detecting preamble index
indicator 13 of the uncommon information.
The detecting preamble index indicator 13 may include the RA
preamble index 5, preamble existence bit 3, and information
discrimination bit 4a corresponding to every terminal that attempts
RA. Here, when the preamble existence bit 3 is set to zero, for
example, it may indicate a last RA preamble index existing in the
detecting preamble index indicator 13.
Also, the detecting preamble index indicator 13 may include the
non-contention RA preamble index and contention RA preamble index.
In this instance, the contention RA preamble index may exist next
to the non-contention RA preamble index.
The contention response message 15 and non-contention response
message 14 is setup information with respect to a control
information message to be transmitted after the terminal receives
the RA response message. The contention response message 15 is a
message with respect to a terminal that attempts RA in a contention
scheme and the non-contention response message 14 is a message with
respect to a terminal that attempts RA in a non-contention scheme.
In this instance, the contention response message 15 and the
non-contention response message 14 may respectively include a
plurality of contention response information 11a and non-contention
response information 11. Also, the contention response information
11a of the contention response message 15 and the non-contention
response information 11 of the non-contention response message 14
may be ordered corresponding to an order of the RA preamble index 5
of the detecting preamble index indicator 13.
The contention response information 11a included in the contention
response message 15 may include uplink transmission timing
alignment information 6, uplink transmission power correction
information 7, uplink radio resource allocation information 8, and
temporarily allocated terminal identifier 9.
The uplink transmission timing alignment information 6 indicates
information to align the uplink transmission time of the terminal
that transmits the RA preamble index 5. The uplink transmission
power correction information 7 indicates transmission power
correction information of the terminal that transmits the RA
preamble index 5. The uplink radio resource allocation information
8 indicates uplink radio resource information that enables the
terminal that attempts RA to transmit control information to an
uplink after receiving the RA response message. The temporarily
allocated terminal identifier 9 indicates an identifier that is
temporarily allocated to the terminal for discriminating the
terminal that attempts RA when scheduling is performed in the base
station.
The non-contention response information 11 included in the
non-contention response message 14 may include only the uplink
transmission timing alignment information 6 and uplink transmission
correction information 7 since it does not requires the temporarily
allocated terminal identifier, unlike the contention response
information 11a. In the RA response message, the non-contention
response message may be located before the contention response
message 15.
A boundary of the mentioned non-contention response information 11
and the contention response information 11a may be discriminated by
the number of non-contention response information and preamble
existence bit 3.
For instance, an RA preamble index corresponding to a value set to
the number of non-contention response information 1 indicates a
last non-contention RA preamble index. Also, when the preamble
existence bit 3 of the last non-contention RA preamble index is set
to one, a subsequent RA preamble index may be a contention RA
preamble index. Accordingly, since the RA preamble index
discriminates a non-contention index from contention index, a
boundary of the non-contention response information and contention
response information respectively corresponding to each RA preamble
index may be discriminated.
The RA response message according to the first example embodiment
is not limited to a drawing as shown in FIG. 3, and the common
information 12 may be constituted only by the number of
non-contention response information 1 and RA overload state
information 2. Also, the detecting preamble index indicator 13 may
include only the RA preamble index 5 and preamble existence bit
3.
However, the base station forms the RA response message including
information discrimination bit 4a, and thus there is no need to fix
the common information 12 to a specific location of the RA response
message. Also, the base station may form the RA response message
including the common information 12 selectively when required and
transmit.
Also, the RA response message according to the first example
embodiment of the present invention may introduce the number of
non-contention response information 1 to discriminate the
non-contention response information from contention response
information, and thereby can use the non-contention response
information of a small size. Finally, as the format of the message
is minimized, application of the radio resources is improved.
FIG. 4 illustrates a format of an RA response message according to
a second example embodiment of the present invention.
Referring to FIG. 4, since the format of the RA response message
according to the second example embodiment is identical with the
format of RA response message illustrated with reference to FIG. 3,
description thereof will be omitted.
However, common information 12 include a preamble existence bit 3,
information discrimination bit 4a, reserved field 4, and RA
overload state information 2, and may be composed of one byte.
Also, a response message 15a may include uplink transmission timing
alignment information 6, uplink transmission power correction
information 7, uplink radio resource allocation information 8, and
temporarily allocated terminal identifier 9 with respect to a
terminal that attempts RA without discrimination of a
non-contention response message or contention response message.
FIG. 5 illustrates a format of an RA response message according to
a third example embodiment of the present invention.
Referring to FIG. 5, since the format of the RA response message
according to the third example embodiment is identical with the
format of RA response message illustrated with reference to FIG. 3,
description thereof will be omitted.
However, common information 12 includes a preamble existence bit 3,
information discrimination bit 4a, number of non-contention
response information 1, number of contention response information
16, and RA overload state information 2.
In this instance, the common information 12, for instance, may
include preamble existence bit 3 of one byte, information
discrimination bit 4a, number of non-contention response
information 16 and RA overload state information 2 of one byte, and
may be composed of three bytes.
Also, although not illustrated in FIG. 5, when the common
information is constituted by only the number of non-contention
response information, the number of contention response
information, and RA overload state information, a detecting
preamble index indicator may be constituted by an RA preamble
index.
That is, the detecting preamble index indicator may not include the
preamble existence bit and information discrimination bit, and may
be constituted including a reserved field of two bytes, thereby
having an advantage of flexibility with respect to applications of
bits.
FIG. 6 illustrates a format of an RA response message according to
a fourth example embodiment of the present invention.
Referring to FIG. 6, since the format of the RA response message
according to the fourth example embodiment is identical with the
format of RA response message illustrated with reference to FIG. 4,
description thereof will be omitted.
However, a number of bits of transmission power correction
information 7 decreases in response information 26 and uplink
resource allocation information 8 is organized into radio resource
location information of UL Grant 24 indicating a sub-carrier index
of an allocated uplink and transmission format information 25.
Here, the uplink transmission power correction information 7 and
transmission format information 25 may be set to a minimum number
of bits by introducing a special range, namely power correcting
level range, and a modulation and encoding level for RA response
information.
Accordingly, an order of the uplink transmission power correction
information 7, UL Grant 24, and transmission format information 25
may be arranged, and thus a minimum number of bits being processed
to extract each field in the RA response information is
possible.
Therefore, the response information is constituted by minimum
resources unlike that illustrated in FIG. 3, thereby maximizing
utilization of radio resources.
FIG. 7 illustrates an RA procedure of the cellular system according
to the present invention.
Referring to FIG. 7, first, a base station receives an RA preamble
from a terminal for RA in operation S10.
Subsequently, the base station transmits an RA response message to
the terminal in operation S20.
The base station transmits the RA response message including an RA
preamble sequence, uplink resource information of the terminal, and
overload state information with respect to the RA to the terminal.
The RA response message may further include a number of
non-contention response information, number of contention response
information, and preamble existence bit indicating that an RA
preamble corresponding to an additional terminal excluding the
terminal exists.
Subsequently, the base station receives control information in
operation S30.
The base station receives the control information generated based
on the RA response message from the terminal.
Here, the base station receives a control information message such
as a radio resource control connection formed by power and a
modulation scheme corresponding to the response information of the
RA response message and the like through uplink resource
information of the response information at the time of uplink
transmission.
Next, the base station transmits the control response information
in operation S30.
A method for RA in a cellular system according to the present
invention may be recorded computer-readable media including program
instructions to implement various operations embodied by a
computer. The media may also include, alone or in combination with
the program instructions, data files, data structures, and the
like. The program instructions may be those specially designed and
constructed for the purposes of example embodiments, or they may be
of the kind well-known and available to those having skill in the
computer software arts. Examples of computer-readable media include
magnetic media such as hard disks, floppy disks, and magnetic tape;
optical media such as CD ROM disks and DVD; magneto-optical media
such as floptical disks; and hardware devices that are specially
configured to store and perform program instructions, such as
read-only memory (ROM), random access memory (RAM), flash memory,
and the like. The media may also be a transmission medium such as
optical or metallic lines, wave guides, and the like, including a
carrier wave transmitting signals specifying the program
instructions, data structures, and the like.
Examples of program instructions include both machine code, such as
produced by a compiler, and files containing higher level code that
may be executed by the computer using an interpreter. The described
hardware devices may be configured to act as one or more software
modules in order to perform the operations of the above-described
exemplary embodiments of the present invention.
A method and apparatus for RA according to example embodiments of
the present invention use an RA response message in byte alignment,
thereby improving operational efficiency of a terminal. Also, the
method and apparatus use information about existence of an RA
preamble index, and thereby can use radio resources
efficiently.
Although a few embodiments of the present invention have been shown
and described, the present invention is not limited to the
described embodiments. Instead, it would be appreciated by those
skilled in the art that changes may be made to these embodiments
without departing from the principles and spirit of the invention,
the scope of which is defined by the claims and their
equivalents.
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