U.S. patent number RE39,673 [Application Number 10/985,830] was granted by the patent office on 2007-06-05 for method of providing burst timing for high-speed data transmission in a base station transceiver system of a mobile communication system.
This patent grant is currently assigned to Samsung Electronics Co., Ltd.. Invention is credited to Yong Chang, Hyun-Seok Lee.
United States Patent |
RE39,673 |
Lee , et al. |
June 5, 2007 |
Method of providing burst timing for high-speed data transmission
in a base station transceiver system of a mobile communication
system
Abstract
A method of establishing a supplemental channel (SCH) to provide
burst timing for high-speed data transmission in a mobile
communication system is disclosed. In the SCH establishing method,
a source base station transceiver determines that a traffic burst
exists and sends a target base station transceiver a burst request
message. The burst request message includes forward and reverse
burst timing information and channel use time information, which is
determined in consideration of a discontinuous transmission (DTX)
mode, in order to reserve necessary resources, when a large amount
of high rate data is to be transmitted. Then, the target base
station transceiver sends the source base station transceiver a
burst response message including information about resources
committed to the traffic burst.
Inventors: |
Lee; Hyun-Seok (Seoul,
KR), Chang; Yong (Songnam-shi, KR) |
Assignee: |
Samsung Electronics Co., Ltd.
(KR)
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Family
ID: |
22460317 |
Appl.
No.: |
10/985,830 |
Filed: |
November 10, 2004 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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60133790 |
May 12, 1999 |
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Reissue of: |
09570844 |
May 12, 2000 |
06490268 |
Dec 3, 2002 |
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Current U.S.
Class: |
370/342; 370/348;
370/335; 370/310.1 |
Current CPC
Class: |
H04W
52/386 (20130101); H04W 52/221 (20130101); H04B
7/18552 (20130101); H04W 52/228 (20130101); H04W
36/16 (20130101); H04W 52/287 (20130101); H04W
72/04 (20130101); H04W 88/08 (20130101); H04W
52/08 (20130101); H04W 72/042 (20130101); H04B
7/2628 (20130101); H04W 36/18 (20130101); H04W
52/54 (20130101); H04W 92/12 (20130101); H04W
72/0413 (20130101); H04W 52/44 (20130101); H04W
88/12 (20130101); H04W 72/0466 (20130101); H04W
48/08 (20130101) |
Current International
Class: |
H04B
7/216 (20060101) |
Field of
Search: |
;370/310.1,310.2,328,329,335,342,340,341,348,395.65,338,401,431,437,438,439,442,465,468 |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
Other References
"Mobile Station-Base Station Compatibility Standard for Wideband
Spread Spectrum Cellular Systems", TIA/EIA Standard, Mar. 1999.
cited by other.
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Primary Examiner: Shah; Chirag
Attorney, Agent or Firm: The Farrell Law Firm
Parent Case Text
This Application claims the benefit of 60/133,790, filed May 12,
1999.
Claims
What is claimed is:
1. A method of establishing a supplemental channel (SCH) in a
mobile communication system, comprising the steps of: determining
that a traffic burst exists; sending a target base station
transceiver a burst message in order to reserve necessary resources
when a large amount of high rate data is to be transmitted, said
burst request message being sent by a source base station
transceiver, said burst request message further including burst
timing information to support a duration and start time of the
traffic burst; and sending the source base station transceiver a
burst response message including information about resources
committed to the traffic burst by the target base station
transceiver.
2. The method of claim 1, wherein the burst request message
includes an information field in which a physical channel type is
designated, said physical channel type being designated in such a
way that an IS-95 standard physical channel is distinguished from a
CDMA-2000 physical channel.
3. The method of claim 2, wherein the physical channel type
designations include a fundamental channel (FCH) and a supplemental
channel (SCH) of the IS-95 standard, as well as a fundamental
channel (FCH), a dedicated control channel (DCCH), and a
supplemental channel (SCH) of the CDMA-2000 standard.
4. The method of claim 1, wherein the burst timing information
includes: a system time at which a forward physical channel is
assigned; a system time at which a reverse physical channel is
assigned; a field indicating whether a forward SCH is assigned for
an infinite period or not; a field indicating whether a reverse SCH
is assigned for an infinite period or not; a duration of the
forward physical channel; and a duration of the reverse physical
channel.
5. The method of claim 4, wherein the reverse burst timing
information additionally includes: a begin preamble at which the
number of preamble frames on a reverse SCH at the start of
transmission; a resume preamble, at which the number of preamble
frames on a reverse SCH at the start of retransmission; and a
reverse burst DTX duration at which a mobile station stops
transmission of a reverse SCH before resuming transmission for a
period assigned on the reverse SCH.
6. The method of claim 4, wherein the physical channel is an SCH or
a supplemental code channel (SCCH).
7. The method of claim 1, wherein the forward burst timing
information includes a forward burst timing information and a
reverse burst timing information.
8. The method of claim 1, wherein the burst request message
includes information about an A3 interface traffic channel protocol
specification, said A3 interface traffic channel protocol
specification having a protocol for high-speed data
transmission.
9. The method of claim 8, wherein the A3 traffic channel protocol
specification includes an AAL2 (ATM Adaptation Layer 2) protocol
for voice service and an AAL5 (ATM Adaptation Layer 5) protocol for
transmission of high rate data.
10. A method for assigning a channel when a base station controller
receives a burst timing message from a base station transceiver in
a mobile communication system, comprising the steps of: receiving a
burst timing message; reading an action time unit from the burst
timing message, if the burst timing message includes forward burst
timing information; setting an action time unit in which a physical
channel is set up; determining from the burst timing message
whether the physical channel is to be assigned for a definite
duration or for an indefinite duration; setting a burst duration to
a value set in the burst timing message if it is determined that
the assignment is for a definite duration; setting a burst duration
to be maintained until the physical channel is released or a mobile
station state transitions to a dormant state, if it is determined
that the assignment is for an indefinite duration; and assigning a
prepared forward physical channel at an action start time set by
the message.
11. A method for assigning a channel when a base station
transceiver receives a burst timing message from a base station
controller in a mobile communication system, comprising the steps
of: receiving a burst timing message; reading an action time unit
from the burst timing message, if the burst timing message includes
reverse burst timing information; setting an action time unit in
which a physical channel is set up; determining from the burst
timing message whether the physical channel it to be assigned for a
definite duration or for an indefinite duration; setting a burst
duration to a value set in the burst timing message if it is
determined that the assignment is for a definite duration; setting
a burst duration to be maintained until the physical channel is
released or a mobile station state transitions to a dormant state,
if it is determined that the assignment is for an indefinite
duration; and reading a reverse discontinuous transmission (DTX)
duration field in the burst timing message, said reverse DTX
duration field being set for the mobile station; setting a maximum
DTX duration of a reverse physical channel; setting a number of
preamble frames to be received when the reverse physical channel is
assigned; setting a number of preamble frames to be received after
a DTX period, said number of preamble frames based on information
in the burst timing message; and assigning a prepared reverse
physical channel at an action start time set by the message.
.Iadd.12. A method of establishing a supplemental channel (SCH) in
a mobile communication system, comprising the steps of: determining
that a traffic burst exists; sending toward a target base station a
burst request message in order to reserve necessary resources for
the traffic burst, said burst request message being sent from the
direction of a source base station, and including burst timing
information to indicate a duration and start time of the traffic
burst; and sending toward the source base station a burst response
message including information about necessary resources committed
to the traffic burst, the burst response message being sent from
the by the target base station; wherein the burst timing
information includes a forward burst timing information and a
reverse burst timing information..Iaddend.
.Iadd.13. The method of claim 12, wherein the burst request message
includes an information field that is used to designate a physical
channel type, said physical channel type being designated in such a
way that an IS-95 standard physical channel is distinguished from a
CDMA-2000 physical channel..Iaddend.
.Iadd.14. The method of claim 13, wherein the physical channel type
designations designate at least one of a fundamental channel (FCH),
and a supplemental channel (SCH) of the IS-95 standard, as well as
a fundamental channel (FCH), a dedicated control channel (DCCH),
and a supplemental channel (SCH) of the CDMA-2000
standard..Iaddend.
.Iadd.15. The method of claim 12, wherein the burst timing
information includes: a system time at which a forward physical
channel is assigned; a system time at which a reverse physical
channel is assigned; a duration of the forward physical channel;
and a duration of the reverse physical channel..Iaddend.
.Iadd.16. The method of claim 15, wherein the burst timing
information additionally includes: a begin preamble which is the
number of preamble frames on a reverse SCH at the start of
transmission; a resume preamble which is the number of preamble
frames on a reverse SCH at the start of retransmission; and a
reverse burst DTX duration at which a mobile station stops
transmission of a reverse SCH before resuming transmission for a
period assigned on the reverse SCH..Iaddend.
.Iadd.17. The method of claim 15, wherein the physical channel is
one of an SCH and a supplemental code channel (SCCH)..Iaddend.
.Iadd.18. The method of claim 12, wherein the burst request message
includes information about an A3 interface traffic channel protocol
specification, said A3 interface traffic channel protocol
specification having a protocol for high-speed data
transmission..Iaddend.
.Iadd.19. The method of claim 19, wherein the A3 interface traffic
channel protocol specification includes an AAL2 (ATM Adaption Layer
2) protocol for voice service and an AAL5(ATM Adaptation Layer 5)
protocol for transmission of high rate data..Iaddend.
.Iadd.20. A method for assigning a channel when a burst timing
message is sent from a direction of a source base station toward a
target base station in a mobile communication system, comprising
the steps of: receiving a burst timing message; reading an action
time unit field from the burst timing message, if the burst timing
message includes forward burst timing information; setting an
action time unit for a point of time at which a physical channel is
set up; determining from the burst timing message whether the
physical channel is to be assigned for a definite duration or for
an indefinite duration; setting a burst duration to a value set in
the burst timing message if it is determined that the assignment is
for a definite duration; setting a burst duration to be maintained
until the physical channel is released or a mobile station state
transitions to a dormant state, if it is determined that the
assignment is for an indefinite duration; and assigning a prepared
forward physical channel at an action start time set by the
message..Iaddend.
.Iadd.21. The method of claim 20, further comprising the steps of:
reading a reverse discontinuous transmission (DTX) duration field
in the burst timing message, said reverse DTX duration field being
set for the mobile station; setting a maximum DTX duration of a
reverse physical channel; setting a number of preamble frames to be
received when the reverse physical channel is assigned; and setting
a number of preamble frames to be received after a DTX period, said
number of preamble frames based on information in the burst timing
message..Iaddend.
.Iadd.22. A system for establishing a supplemental channel (SCH) in
a mobile communication system, comprising: a source base station
configured to send a burst request message to a target base station
for reserving necessary resources for a traffic burst, when the
traffic burst exists, said burst request message including burst
timing information indicating a duration and start time of the
traffic burst; and a target base station configured to receive the
burst request message, and send a burst response message to the
source base station, the burst response message including
information about communication resources committed to the traffic
burst; wherein the burst timing information includes a forward
burst timing information and a reverse burst timing
information..Iaddend.
.Iadd.23. The system of claim 22, wherein the burst request message
includes an information field that is used to designate a physical
channel type, said physical channel type being designated in such a
way that an IS-95 standard physical channel is distinguished from a
CDMA-2000 physical channel..Iaddend.
.Iadd.24. The method of claim 23, wherein the physical channel type
designations designate at least one of a fundamental channel (FCH),
and a supplemental channel (SCH) of the IS-95 standard, as well as
a fundamental channel (FCH), a dedicated control channel (DCCH),
and a supplemental channel (SCH) of the CDMA-2000
standard..Iaddend.
.Iadd.25. The method of claim 22, wherein the burst timing
information includes: a system time at which a forward physical
channel is assigned; a system time at which a reverse physical
channel is assigned; a duration of the forward physical channel;
and a duration of the reverse physical channel..Iaddend.
.Iadd.26. The method of claim 25, wherein the burst timing
information additionally includes: a begin preamble which is the
number of preamble frames on a reverse SCH at the start of
transmission; a resume preamble which is the number of preamble
frames on a reverse SCH at the start of retransmission; and a
reverse burst DTX duration at which a mobile station stops
transmission of a reverse SCH before resuming transmission for a
period assigned on the reverse SCH..Iaddend.
.Iadd.27. The method of claim 25, wherein the physical channel is
one of an SCH and a supplemental code channel (SCCH)..Iaddend.
.Iadd.28. A method of establishing a supplemental channel (SCH) in
a mobile communication system, comprising the steps of: determining
that a traffic burst exists; sending a target base station a burst
request message in order to reserve necessary resources when a
large amount of high rate data is to be transmitted, said burst
request message being sent by a source base station, said burst
request message further including burst timing information to
support a duration and start time of the traffic burst; and sending
the source base station a burst response message including
information about resources committed to the traffic burst by the
target base station; wherein the burst timing information includes
a forward burst timing information and a reverse burst timing
information..Iaddend.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a method of providing
burst timing in a base station (BS) of a mobile communication
system, and in particular, to a method of providing forward and
reverse burst timing with respect to the time of using a
supplemental channel (SCH) and a supplemental code channel (SCCH)
for rapid transmission of a large amount of data in a BS, taking
into account a discontinuous transmission (DTX) mode.
Specifically, the present invention relates to a method of
providing burst timing definable with respect to the use time of a
physical channel and the start and end time of data and a method of
supporting an AAL5 protocol for high-speed data transmission
between BTSs by a base station transceiver system (BTS) and a base
station controller (BSC) in a mobile communication system under a
ratio channel environment which allows high-speed data
processing.
2. Description of the Related Art
Typical CDMA (Code Division Multiple Access) mobile communication
systems provide mainly voice service, but the IMT-2000
(International Mobile Telecommunications-2000) standard has been
developed to additionally provide high-speed data transmission.
IMT-2000 mobile communication systems are capable of transmitting
high quality voice and moving pictures, as well as Internet
browsing.
A CDMA mobile communication system is comprised of a BS including a
BTS and a BSC, a mobile switching center (MSC), and a mobile
station (MS). Radio links between an MS and a BTS include a forward
link directed from the BTS to the MS and a reverse link directed
from the MS to the BTS.
All channels are divided into physical channels and logical
channels. A logical channel .is set on a physical channel and it is
possible that a plurality of logical channels are set on one
physical channel. If the physical channel is released, the logical
channels are automatically released. However, a physical channel is
not necessarily created to set up a new logical channel. If a
physical channel that can carry another logical channel has already
been occupied for other logical channels, all that should be done
is to assign the new logical channel to the already established
physical channel.
Physical channels are categorized into dedicated channels and
common channels according to their characteristics. The dedicated
channels are so named because they are dedicated to communication
between a BS and a particular MS, and include a fundamental channel
(FCH), a dedicated control channel (DCCH), and a SCH. The FCH,
compatibly used with TIA/EIA-95-B, transmits voice, data, and
signaling signals. The common channels indicate channels, commonly
shared by a BS and a plurality of MSs. A forward physical channel
transmitted to the MSs from the BS is a paging channel, and a
reverse channel transmitted to the BS from an MS is an access
channel. These common channels are compatible with IS-95-B.
Data communication in a mobile communication system is
characterized by bursts of concentrated data transmission
interspersed between long periods of no data transmission.
Accordingly, the next generation mobile communication system is
developed in such a way that it can operate in a discontinuous
transmission (DTX) mode in which a dedicated channel is only
assigned when there is data to be transmitted.
In the DTX mode, frame data is transmitted only when transmission
data exists in a wired communication system or in a mobile
communication system. Hence, if transmission data is absent for a
predetermined time period in the DTX mode, frame data is not
transmitted. The DTX mode has the distinctive advantages of minimum
transmission power, reduction of the strength of interference which
adversely affects the system, and increase of total system
capacity.
The DTX mode is supported on a DCCH and an SCH. Because of this,
the DCCH can be used as a control channel which provides an
efficient packet service. In DTX mode, null frames are transmitted
on the DCCH for power control and no data is transmitted on the
SCH. Considering limited radio resources, BS capacity, and power
consumption of an MS, dedicated traffic and control channels are
connected only during actual data transmission and released during
non-transmission periods while in the DTX mode. Communication is
conducted on a common channel while the dedicated channels are
released. As a result, the usage efficiency of the radio resources
is increased. Various channel states are set according to channel
assignment and the presence or absence of state information in
order to implement the DTX mode.
FIG. 1 is a state transition diagram for a typical packet service
in a mobile communication system.
Referring to FIG. 1, a packet service is comprised of an active
state 11, a control hold state 12, a suspended state 13, a dormant
state 14, a packet null state 15, and an initialization state 10.
Service options are connected in the control hold state 12, the
active state 11, and the suspended state 13. It is to be noted
herein that the present invention pertains to a base station which
supports the DTX mode on an SCH and a DCCH in the active state 11
and the control hold state 12.
FIG. 2 illustrates a reference model of 3G IOS (Interoperability
Specifications) for a digital air interface between an MSC and a BS
and between BSs in a general mobile communication system.
Referring to FIG. 2, an A1 interface and an A2/A5 (exclusive for
circuit data) interface are defined for transmitting a signal and
transmitting user information, respectively, between an MSC 20 and
a BSC 32. An A3 interface is defined to connect a target BS 40 to a
frame selection/distribution function unit (SDU) 34 of a source BS
30 for soft/softer handoff between BSs. Using the A3 interface,
signaling and user data are transmitted between the target BS 40
and the SDU 34 of the source BS 30. An A7 interface is defined to
transmit/receive signals between the target BS 40 and the source BS
30 for soft/softer handoff between BSs. Wired communications links
between the BSs 30 and 40 and between the BS 30 and the MSC 20 are
a forward link directed from the MSC 20 to the BS 30, a reverse
link directed from the BS 30 to the MSC 20, and a link connected
between the BSs 30 and 40. The MSC 20 has a call control &
mobility management block 22 and a switch 24. The MSC 20 is
connected to a data network (not shown) such as the Internet via an
inter-working function (IWF) block 50.
FIG. 3 illustrates a signal flow by which an SCH is established
between a source BS and a target BS in conventional technology.
This procedure is executed to establish an SCH between the source
BS and the target BS when a large amount of high rate data is
received from an external Packet Data Service Node (PDSN) or data
is to be transmitted by assigning the SCH upon call origination
from an MS.
Referring to FIG. 3, the source BS 30 recognizes that an MS has
origination/termination data to transmit/receive to/from another MS
or the PSDN (3a). Then, the source BS 30 determines a traffic burst
required during service instance support, selects the target BS 40
which will assist the determined traffic burst, and transmits a
burst request message (A7-Burst Request msg.) to the target BS 40,
requesting reservation of necessary resources (3b). The target BS
40 checks whether part or all of the requested resources are
available and transmits a burst response message (A7-Burst Response
msg.) inlcuding information about the resources committed for the
traffic burst to the source BS 30 (3c). Meanwhile, the source BS 30
awaits receipt of the burst response message for a first
predetermined time. Tbstreq after transmission of the burst request
message. Upon receipt of the burst response message within Tbstreq,
the source BS 30 prepares a set of frame selectors based on the
information of the burst response message and transmits a burst
activate message (A7-Burst Activate msg.), which indicates a set of
the committed resources to be actually used, to the target BS 40
(3d). If timer Tbstreq expires, the source BS may choose to send an
A7-Burst Request message again.
Meanwhile, the target BS 40 awaits receipt of the burst activate
message for a second predetermined time Thstcom after transmission
of the burst response message. If the target BS 40 receives the
burst activate message within Tbstcom, it transmits a connect
message (A3-connect msg.), which is for connecting all cell
resources to be used for the traffic burst to the designated frame
selectors, to the source BS 30 (3e). The source BS 30 transmits a
connect acknowledgment message (A3-connect Ack msg.) to the target
BS 40, notifying the target BS 40 that physical channels to support
the traffic burst are ready (3f). If timer Thstcom expires, the
target BS may decommit all radio resources committed for the
cell(s) included in this message. Meanwhile, the target BS 40
awaits receipt of the connect acknowledgment message for a third
predetermined time Tconn3 after transmission of the connect
message. If the target BS 40 receives the connect acknowledgment
message within Tconn3, it transmits a burst activate acknowledgment
message (A7-Burst Activate Ack. msg.) to the source BS 30 (3g). If
timer Tconn3 expires, the BS shall include all new cells that would
have been added by the A3-Connect message to the list of
non-committed cells in the A7-Burst Response message.
Meanwhile, the source BS 30 awaits receipt of the burst activate
acknowledgment message for a fourth predetermined time Tbstact
after transmission of the burst activate message in step 3d. If the
source BS 30 receives the burst activate acknowledgment message
within Tbstact, it transmits a command through a scan message
(SCAM_msg.) to an MS, ordering the MS to prepare for the traffic
burst (3h). Then, the MS a layer 2 acknowledgment message (Layer 2
Ack. msg.) to the source BS 30 in response to the scan message
(3i). The network and the MS exchange forward or reverse traffic
burst information for a predetermined time period or until the
source BS 30 expands or ends the traffic burst (3j). If timer
Tbstact expires, the source BS may choose to resend this message,
to terminate traffic burst preparations, or to request that the MSC
clear the call association.
The structure of the burst request message transmitted in step 3b
is shown in Table 1. The burst request message is an A7 interface
message by which a source BS requests reservation of resources to
support data traffic burst to a target BS.
TABLE-US-00001 TABLE 1 Information Element Element Direction Type
Message Type II Source BS > Target BS M Call Connection
Reference Source BS > Target BS O R Band Class Source BS >
Target BS O R Downlink Radio Environment Source BS > Target BS O
R CDMA Serving One Way Delay Source BS > Target BS O R Privacy
Info Source BS > Target BS O R A3 Signaling Address Source BS
> Target BS O R Correlation ID Source BS > Target BS O R SDU
ID Source BS > Target BS O R Mobile Identity (IMSI/MIN) Source
BS > Target BS O R Mobile Identity (ESN) Source BS > Target
BS O R Frame Selector Info Source BS > Target BS O R A7 Cell
Info Source BS > Target BS O R Burst Timing Source BS >
Target BS O R M: Mandatory, O: Optional, R: Recommend, C:
Conditionally Recommend
Referring to Table 1, burst request message fields provide
information as described below: 1. Call Connection Reference: the
only identification used for call connection in the whole system;
2. Band Class: a frequency band; 3. Downlink Radio Environment: a
signal strength measurement value provided by a mobile station; 4.
CDMA Serving One Way Delay: an estimated value of a
single-directional delay in an MS with respect to a cell related
with REF_PN; 5. Privacy Info: (public and private) CDMA long code
mask information; 6. A3 Signaling Address: network node including
an SDU instance in use for a call; 7. Correlation ID: a factor of
correlating a request message to a response message; 8. SDU ID: a
particular SDU instance ID in one SDU node; 9. Mobile Identity
(ESN): Electronic Serial Number (ESN) of an MS; 10. Frame Selector
Info: a set of frame selectors used for one call association. This
field is used to add a new frame selector to a call association or
amend the property of a frame selector in an existing call
association; 11. A7 Cell Info: Information about a set of cells to
which specific physical cahnnels are added for a call association;
and 12. Burst Timing: a factor representative of the period and
start time of a data burst on a set of physical channels.
The structure of the burst response message in step 3c is shown
below in Table 2. The burst response message is an A7 interface
message as a response for the burst request message (A7-Burst
Request msg.) by which the source BS requests reservation of
resources to support a data traffic burst to the target BS.
TABLE-US-00002 TABLE 2 Information Element Element Direction Type
Message Type II Source BS > Target BS M Call Connection
Reference Source BS > Target BS O R Correlation ID Source BS
> Target BS O C A7 Committed Cell Info Source BS > Target BS
O R A7 Uncommited Cell Info Source BS > Target BS O R Burst
Timing Source BS > Target BS O R M: Mandatory, O: Optional, R:
Recommend, C: Conditionally Recommend
1. Call Connection Reference: an identification for a call
connection which is unique to the whole system; 2. Correlation ID:
a factor of correlating a request message to a response message; 3.
A7 Committed Cell Info: information about a set of cells committed
to specific physical channels for a call association by a target
BS; and 4. A7 Uncommitted Cell Info: information about a set of
cells uncommitted to specific physical channels for a call
association by a target BS.
The burst activate message (A7-Burst Activate msg.) in step 3d is
shown in Table 3. The burst activate message is an A7 interface
message which the source BS transmits to the target BS to commit a
set of reserved resources for supporting a data traffic burst.
TABLE-US-00003 TABLE 3 Information Element Element Direction Type
Message Type II Source BS > Target BS M Call Connection
Reference Source BS > Target BS O R Correlation ID Source BS
> Target BS O C Frame selector Info Source BS > Target BS O R
A7 Cell Info Source BS > Target BS O R M: Mandatory, O:
Optional, R: Recommend, C: Conditionally Recommend
1. Call Connection Reference: an identification for a call
connection which is unique to the whole system; 2. Correlation ID:
a factor of correlating a request message to a response message; 3.
Frame Selector Info: a set of frame selectors used for one call
association. This field is used to add a new frame selector to a
call association or amend the property of a frame selector in an
existing call association; and 4. A7 Cell Info: information about a
set of cells to which specific physical channels are added for a
call association.
The information elements of the burst activate acknowledgment
message (A7-Burst Activate Ack. msg.) in step 3g is shown in Table
4. The burst activate acknowledgment message is an A7 interface
response message to the burst activate message which the source BS
transmitted to the target BS in order to commit a set of reserved
resources for supporting the data traffic burst.
TABLE-US-00004 TABLE 4 Information element Element Direction Type
Message Type II Target BS > Source BS M Call Connection
Reference Target BS > Source BS O R Correlation ID Target BS
> Source BS O C A7 Uncommited Cell Info Target BS > Source BS
O R M: Mandatory, O: Optional, R: Recommend, C: Conditionally
Recommend
1. Call Connection Reference: an identification for a call
connection which is unique to the whole system; 2. Correlation ID:
a factor of correlating a request message to a response message;
and 3. A7 Uncommitted Cell Info: information about a set of cells
uncommitted to specific physical channels for a call association by
a target BS.
Table 5 lists the fields of the Frame Selector Info information
element included in the burst request message (A7-Burst Request
msg.) shown in Table 1 and the burst activate message (A7-Burst
Activate msg.) shown in Table 3.
TABLE-US-00005 TABLE 5 7 6 5 4 3 2 1 0 Octet A3/A7 Element
Identifier 1 Length 2 Count of Frame Selectors 3 Length of Frame
Selector Information 4 Reserved Frame Selector Index 1 5 Physical
Channel Type 1 6 A3 traffic Channel Protocol Stack 1 7 Frame Offset
1 8 Reserved (MSB) 9 ARFCN1 (LSB) 10 Forward Channel Bandwidth 1 11
Reverse Channel Bandwidth 1 12 Reserved Frame selector Index 2 13
Physical Channel Type 2 14 A3 Traffic Channel Protocol Stack 2 15
Frame Offset 2 16 Reserved (MSB) 17 ARFCN2 (LSB) 18 Forward Channel
Bandwidth 2 19 Reverse Channel Bandwidth 2 20 . . . . . . Reserved
Frame Selector Index a m Physical Channel Type a m + 1 A3 Traffic
Channel Protocol Stack n m + 2 Frame Offset n m + 3 Reserved (MSB)
m + 4 ARFCN n (LSB) m + 5 Forward Channel Bandwidth n m + 6 Reverse
Channel Bandwidth n m + 7
1. Count of Frame Selectors: number of frame selectors; 2. Length
of Frame Selector Information: the number of octets used to
transmit a set of fields for each instance of a frame selector; 3.
Frame Selector Index: a binary value used to uniquely indicate a
frame selector used for a call association; and 4. Physical Channel
Type: the type of a physical channel associated with a designated
frame selector. Table 6 below shows the hex values taken by the
Physical Channel Type field. 5. Frame Offset: frame offset for a
given frame selector; 6. ARFCN (Actual Radio Frequency Channel
Number): real radio frequency channel number related with a band
class for a call association; 7. Forward Channel Bandwidth: the
band of a forward channel assocaited with a frame selector; and 8.
Reverse Channel Bandwidth: the band of a reverse channel assocaited
with a frame selector.
TABLE-US-00006 TABLE 6 Value (Hex) Physical Channel Type 01H
Fundamental Channel (FCH) TIA/EIA/-95 02H Supplemental Channel
(SCH) TIA/EIA/-95 03H Dedicated Control Channel (DCCH) TIA/EIA/-95
8OH to 9FH Reserved for UMTS All other values Reserved
As shown in Table 6, since the Physical Channel Type field only
defines IS-95 channels, and not CDMA-2000 channels, when the
CDMA-2000 standard is applied to a mobile communication system, the
Base Stations will not be able to identify channels because the
CDMA-2000 channels will be confused with IS-95 channels.
The A3 Traffic Channel Protocol Stack is a protocol stack used for
an A3 traffic channel attached to a given frame selector. Its
structure is shown below, in Table 7.
TABLE-US-00007 TABLE 7 Value (Hex) Protocol Stack 01H
AAL2/ATM/Physical Layer All other values Reserved
As noted from Table 7, only the AAL2 (ATM Adaptation Layer 2)
protocol, which is used for voice service, is defined in the
protocol stack used for the A3 traffic channel. Therefore, the
protocol stack is not fit for high rate data.
Burst Timing included in the burst request message (A7-Burst
Request msg.) shown in Table 1 and the burst response message
(A7-Burst Response msg.) shown in Table 2 have the following
information elements, shown below in Table 8.
TABLE-US-00008 TABLE 8 7 6 5 4 3 2 1 0 Octet A3/A7 Element
Identifier 1 Length 2 Burst Action Time 3 (MSB) Burst Duraction 4
(LSB) 5
1. Burst Action Time: accurate start time of a data burst; and 2.
Burst Duration: a binary value indicating burst duration expressed
in the number of frames. The binary value is the assignment time of
an IS-95 SCH and an IS-95B SCCH in IS-2000.
The above-described conventional technology has the following
problems within a BS and between BSs, not with a radio link between
a BS and an MS.
There is no way to discriminate between the FCH and SCH in the
IS-95B standard and the FCH, DCCH, and SCH in the CDMA-2000
standard with the Frame Selector Info fields shown in Table 5 in
the procedure shown in FIG. 3. Therefore, a BS cannot adequately
identify channels. Furthermore, high rate data cannot be
transmitted since only the AAL2 protocol, which is used for voice
service, is defined in the A3 Traffic Channel Protocol Stack.
The duration and start time of a data burst cannot be supported on
a concurrent bi-directional SCH or SCCH with the burst timing
message of Table 8. The DTX duration of a reverse SCH and SCCH is
not provided, thereby making it impossible to perform rapid packet
service in a BS. Consequently, a new method should be explored to
process high rate data.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a
method of enabling a BTS to identify channels by defining an
identification (ID) which discriminates between the fundamental and
supplemental channels (FCH and SCH) of the IS-95B standard and the
fundamental, dedicated control, and supplemental channels (FCH,
DCCH, and SCH) of the CDMA-2000 standard in a message transmitted
to or received from a BS.
It is another object of the present invention to provide the AAL5
(ATM Adaptation Layer 5) protocol, which is used to effectively
transmit high rate data, in an A3 traffic channel protocol stack
field.
It is a further object of the present invention to provide a burst
timing message which is defined to support the duration and start
time of a data burst on a concurrent bi-directional SCH or SCCH as
well as to provide the DTX duration of a reverse SCH and SCCH.
It is still another object of the present invention to provide a
method of defining forward and reverse burst timing messages in one
message or defining them separately to be available in either
direction as well as both directions, and expressing the start time
of a burst in various units, to thereby implement a burst operation
at a more accurate time.
These and other objects are achieved by providing a method of
establishing an SCH which allows for burst timing for high-speed
data transmission in a mobile communication system. In the SCH
establishing method, a source base station transceiver determines a
traffic burst and sends a target base station transceiver a burst
request message including forward and reverse burst timing
information and having channel use time, which is determined in
consideration of a discontinuous transmission (DTX) mode in order
to reserve necessary resources, when a large amount of high rate
data is to be transmitted. Then, the target base station
transceiver sends the source base station transceiver a burst
response message including information about resources committed to
the traffic burst.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present
invention will become more apparent from the following detailed
description when taken in conjunction with the accompanying
drawings in which:
FIG. 1 is a state transition diagram for typical packet service in
a mobile communication system;
FIG. 2 illustrates a reference model of 3G IOS for a digital air
interface between an MSC and a BS and between BSs in a typical
mobile communication system;
FIG. 3 is a signal flow in a procedure of establishing an SCH
between a source BS and a target BS according to conventional
technology; and
FIG. 4 is a flowchart illustrating a procedure of receiving a burst
timing message according to an embodiment of the present
invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
A preferred embodiment of the present invention will be described
hereinbelow with reference to the accompanying drawings. In the
following description, well-known functions or constructions are
not described in detail since they would obscure the invention in
unnecessary detail.
In the preferred embodiment of the present invention, in order to
facilitate channel identification in a BTS, an ID field is formed
to discriminate between an FCH and an SCH in the IS-95B standard
and an FCH, a DCCH, and an SCH in the IS-2000 standard in a field
of the Frame Selector Info information element defined in a signal
message transmitted or received within a BS. A message containing
the frame selector information can be the burst request message of
Table 1 or the burst activate message of Table 3, both of which
were mentioned earlier in the description of the prior art.
Table 9 illustrates a modified Physical Channel Type field in the
Frame Selector Info information element according to the preferred
embodiment of the present invention.
TABLE-US-00009 TABLE 9 Value (Hex) Physical Channel Type 01H
Fundamental Channel (FCH) TIA/EIA-95 02H Supplemental Code Channel
(SCCH) TIA/EIA-95B 03H Fundamental channel (FCH) CDMA-2000 04H
Dedicated Control Channel (DCCH) CDMA-2000 05H Supplemental Channel
CDMA-2000 8OH to 9FH Reserved for UMTS All other values
Reserved
In Table 9, the IS-95 FCH and the IS-95B SCH are defined as 01H and
02H, respectively. The FCH, DCCH, and SCH of CDMA-2000 are defined
as 03H, 04H, and 05H. Thus, the FCH and SCH of IS-95B can be
distinguished from the FCH, DCCH, and SCH of IS-2000.
The A3 Traffic Channel Protocol Stack field of Table 5 is modified
as shown below in order to support the AAL5 protocol, which is
appropriate for transmission of high rate data, in an A3 traffic
channel protocol.
TABLE-US-00010 TABLE 10 Value (Hex) Protocol Stack 01H
AAL2/ATM/Physical Layer 02H AAL5/ATM/Physical Layer All other
values Reserved
In accordance with the preferred embodiment of the present
invention, the definition of the message fields as shown in Tables
9 and 10 allows a BTS both to distinguish the FCH and SCH of IS-95B
from the FCH, DCCH, and SCH of CDMA-2000 and to transmit high rate
data.
The preferred embodiment of the present invention defines a new
burst timing message. The burst timing message as shown in Table 11
can support the duration and start time of data burst concurrently
on bi-directional FCHs or SCHs and provide the burst DTX duration
of a reverse SCH and SCCH.
TABLE-US-00011 TABLE 11 7 6 5 4 3 2 1 0 Octet A3/A7 Element
Identifier 1 Length 2 Forward Burst Action (or Start) Time 3
Reverse Burst Action (or Start) Time 4 Reserved For_Infinite
Rev_Burst_DTX.sub.-- Rev_Infinite 5 _Burst.sub.-- Duration
_Burst.sub.-- Duration Duration For_Burst_Duration 6
Rev_Burst_Duration 7 Reserved Begin Preamble Resume Preamble 8
1. Length: the number of octets for information elements following
this field; 2. Forward Burst Action (or Start) Time: system time
when a forward SCH or SCCH is assigned; 3. Reverse Burst Action (or
Start) Time: system time when a reverse SCH or SCCH is assigned; 4.
For_Infinite_Burst_Duration: a field indicating whether a forward
SCH and SCCH are assigned for an infinite period or not. If a BTS
sets this field to 1, the forward SCH or SCCH is assigned for a
predetermined time expressed in the number of 80-ms frames after
the forward burst action time, and, if the BTS sets the field to
0,it is assigned for an infinite period; 5. Rev_Burst_DTX_Duration:
the maximum number of 20-ms frames for which an MS stops
transmission of a reverse SCH or SCCH before resuming transmission
for a period assigned on the reverse SCH or SCCH. This field is set
by a BTS; 6. Rev_Infinite_Burst_Duration: a field indicating
whether a reverse SCH and SCCH are assigned for an infinite period
or not. If a BTS sets this field to 1, the reverse SCH or SCCH is
assigned for a predetermined time expressed in the number of 80-ms
frames after the reverse burst action time, and, if the BTS sets
the field to 0, it is assigned for an infinite period; 7.
For_Burst_Duration: a time period expressed in 80ms units, for
which a forward SCH or SCCH is assigned; 8. Rev_Burst_Duration: a
time period expressed in 80ms units, for which a reverse SCH or
SCCH is assigned; 9. Begin Preamble: the number of preamble frames
transmittable from an MS on a reverse SCH or SCCH at the start of
transmission of the reverse SCH or SCCH; and 10. Resume Preamble:
the number of preamble frames transmittable from an MS on a reverse
SCH or SCCH at the start of re-transmission of the reverse SCH or
SCCH.
The forward and reverse burst timing messages shown in Table 11 can
be defined in one message or in separate messages.
Table 12 shows a forward burst timing message which provides the
duration, start time, and start time unit of a forward data
burst.
TABLE-US-00012 TABLE 12 7 6 5 4 3 2 1 0 Octet A3/A7 Element
Identifier 1 Length 2 Reserved Action (or Start) For_Infinite 3
Time Unit _Burst.sub.-- Duration For_Burst_Duration 4 Forward Burst
Action (or Start) Time 5
1. Length: the number of octets for information elements following
this field; 2. Action (or Start) Time Unit: the action time unit of
a forward burst. A BTS sets this field to a number 1 smaller than
the number of 20-ms frames; 3. For_Infinite_Burst_Duration: a field
indicating whether a forward SCH and SCCH are assigned for an
infinite period or not. If a BTS sets this field to 1, the forward
SCH or SCCH is assigned for a predetermined time expressed in the
number of 80-ms frames after the forward burst action time, and, if
the BTS sets the field to 0, it is assigned for an infinite period;
4. For_Burst_Duration: a time period expressed in 80ms units, for
which a forward SCH or SCCH is assigned; and 5. Forward Burst
Action (or Start) Time: system time when a forward SCH or SCCH is
assigned.
Table 13 shows a reverse burst timing message which provides the
duration, start time, and start time unit of a data burst on a
reverse SCH or SCCH.
TABLE-US-00013 TABLE 13 7 6 5 4 3 2 1 0 Octet A3/A7 Element
Identifier 1 Length 2 Action (or Start) Rev_Burst_DTX_ Rev_Infinite
3 Time Unit Duration _Burst.sub.-- Duration Rev_Burst_Duration 4
Reverse Burst Action (or Start) Time 5 Reserved Begin Preamble
Resume Preamble 6
1. Length: the number of octets for information elements following
this field; 2. Action (or Start) Time Unit: the action time unit of
a reverse burst. A BTS sets this field to a number 1 smaller than
the number of 20-ms frames; 3. Rev_Burst_DTX_Duration: the maximum
number of 20-ms frames for which an MS stops transmission on a
reverse SCH or SCCH before resuming transmission for a period
assigned on the reverse SCH or SCCH. This field is set by a BTS; 4.
Rev_Infinite_Burst_Duration: a field indicating whether a reverse
SCH and SCCH are assigned for an infinite period or not. If a BTS
sets this field to 1, the reverse SCH or SCCH is assigned for a
predetermined time expressed in the number of 80-ms frames after
the reverse burst action time, and, if the BTS sets the field to 0,
it is assigned for an infinite period; 5. Rev_Burst_Duration: a
time period expressed in 80ms units, for which a reverse SCH or
SCCH is assigned; 6. Reverse Burst Action (or Start) Time: system
time when a reverse SCH or SCCH is assigned; 7. Begin Preamble: the
number of preamble frames transmittable from an MS on a reverse SCH
or SCCH at the start of transmission of the reverse SCH or SCCH;
and 8. Resume Preamble: the number of preamble frames transmittable
from an MS on a reverse SCH or SCCH at the start of re-transmission
of the reverse SCH or SCCH.
FIG. 4 is a flowchart illustrating an operation of receiving a
burst timing message according to the preferred embodiment of the
present invention. The procedure will be described in the context
of separately defined forward and reverse burst timing messages
shown in Tables 12 and 13.
Referring to FIG. 4, a BTS determines whether a burst timing
message received from a BSC is forward link or reverse link
information in step 101. If it is forward link information, the BTS
reads the Action Time Unit field from the burst timing message and
determines an action time unit for a time point when an SCH or SCCH
is to be assigned in step 102.
The BTS determines whether the burst duration to be assigned is set
to infinite in the burst timing message in step 103. If the burst
duration is not set to infinite, the BTS sets a burst duration to a
value in the message on an 80-ms basis in step 104, and then
initiates assignment of a forward SCH or SCCH at an action (or
start) time set in the message in step 105.
Meanwhile, if the burst duration is set to infinite in step 103,
the BTS sets the burst duration to be maintained until an SCH or
SCCH service released or a dormant state is entered in step 104-1.
Here, the service covers all services provided on an SCH or SCCH,
including packet, circuit, and ISDN services. After the burst
duration is set, the BTS initiates assignment of the forward SCH or
SCCH at the action (or start) time set in the message in step
105a.
If the burst timing message received from the BSC is reverse link
information in step 101, the BTS reads the Action Time Unit field
from the burst timing message and determines an action time unit
for a time point when an SCH or SCCH is to be assigned in step
102a.
The BTS determines whether the burst duration to be assigned is set
to infinite in the burst timing message in step 103a. If the burst
duration is not set to infinite, the BTS sets the burst duration to
a value in the message on an 80-ms basis in step 104a. In step
105-1, the BTS reads the maximum reverse DTX_Duration field and
sets maximum DTX_Duration on a 10-ms basis for the reverse SCH or
SCCH receiver. In addition, the BTS sets the Begin Preamble and
Resume Preamble when the SCH or SCCH is assigned. Finally, the BTS
initiates assignment of the reverse SCH or SCCH at the action (or
start) time set in the message.
If the burst duration is set to infinite in step 103a, the BTS sets
the burst duration to be maintained until an SCH or SCCH service is
released or a dormant state is entered in step 104-1a. Here, the
service covers all services provided on an SCH or SCCH, including
packet, circuit, and ISDN services. In step 105-1a, the BTS reads
the maximum reverse DTX_Duration field and sets maximum
DTX_Duration on a 10-ms basis for the reverse SCH or SCCH receiver.
On addition, the BTS sets the Begin Preamble and Resume Preamble
when the SCH or SCCH is assigned. Finally, the BTS initiates
assignment of the reverse SCH or SCCH at the action (or start) time
set in the message.
In accordance with the preferred embodiment of the present
invention as described above, when a BTS transmits a high rate data
burst on a physical channel, 1) the AAL5 protocol can be supported
in an A3 traffic channel protocol, 2) the FCH and SCH of the IS-95B
standard can be distinguished from the FCH, DCCH, and SCH of the
CDMA-2000 standard, and 3) high rate data can be effectively
transmitted through an A3 interface. Another advantage of the
present invention is that the duration, start time, and start time
unit of forward and reverse data burst on an SCH or SCCH is
provided through
a newly defined burst timing message to thereby designate a more
accurate burst action time. Furthermore, a reverse DTX duration is
provided so as to support bi-directional high rate packet data.
While the invention has been shown and described with reference to
a certain preferred embodiment thereof, it will be understood by
those skilled in the art that various changes in form and details
may be made therein without departing from the spirit and scope of
the invention as defined by the appended claims.
* * * * *