Note: Descriptions are shown in the official language in which they were submitted.
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METHOD FOR PROVIDING A DATA SERVICE
IN A CDMA COMMUNICATIONS SYSTEM
This is a divisional application of Canadian
Application Serial No. 2,305,524 filed August 3, 1999.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates generally to a code division multiple access
(CDMA) mobile communications system and, more particularly, to a method for
providing a free data service and a charging data service.
2. Description of the Related Art
In a CDMA mobile communications system, it is generally required for a base
station to assign at least one orthogonal code for data communications to each
of a
plurality of mobile stations that request a data service. User data, such as
voice signal
a d packet data, are communicated on dedicated channels that are separately
established between the base station and each individual mobile station.
For that reason, in the related art CDMA communications system, the base
] 5 station has to separately assign dedicated channels to each individual
mobile station
in order to communicate the same data (e.g., packet data) to each of the
multiple
mobile stations.
In a case where the identical data supplied by the system is free information
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available at any time at a plurality ofmobile stations, the related art
utilizes dedicated
cliannels separately assigned to each of the mobile stations is a very
inefficient
method that requires unnecessary communication path and results in
deterioration of
data rate. It is therefore possible for the base station to assign a channel
resource
efficiently by using a specified channel assigned to send free information to
the
multiple mobile stations. This enables a plurality of subscribers to be served
with free
data service of small quantity, such as daily weather and stock information,
through
terminals at any time.
On the other hand, when the data supplied by the system is free information
of large quantity, such as Intemet services and the like, the base station has
to send
charging data only to the mobile stations that request the charging data
service. And,
the inobile stations receiving the charging data services must send billing
information
to the base station. For this procedure, there is a need of separately
establishing and
assigning forward and reverse link channels for data communications between
the
base station and the individual mobile stations that request the charging data
service.
SUMMARY OF THE INVENTION
It is, therefore, an object of the present invention to provide a method for
providing a charging data service and a free data service using channels
efficiently
assigned in a CDMA mobile communications system.
It is another object of the present invention to provide a method for
providing
a fi=ee data service in a CDMA mobile communications system, in which a base
station sends information about a free data channel to a plurality of mobile
stations
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on a common channel and then sending specified free data to the plural mobile
stations on the free data channel.
It is further another object of the present invention to provide a method for
providing a free data service in a CDMA mobile communications system, in which
a mobile station demodulates a common channel received from a base station to
detect information about a free data channel, demodulating the free data
channel
r-eceived from the base station according to the information about the free
data
cliannel and receiving the corresponding free data.
It is still further another object of the present invention to provide a
method for
pi-oviding a cliarging data service in a CDMA mobile communications system, in
which a base station sends a first charging data channel information to a
plurality of
niobile stations on a common channel, assigning the charging data channels
upon
receiving a charging data service request message from a specified mobile
station,
sending a second charging data channel information to the mobile station
requesting
the charging data channel service on the common channel, and sending the
corresponding charging data to the mobile station through the corresponding
charging
data channel upon receiving a service request confirm message from the mobile
station.
It is still further another object of the present invention to provide a
method for
pi-oviding a charging data service in a CDMA mobile communications system, in
which a mobile station demodulates a first charging data channel information
on a
cominon channel, sending the type of desired charging data and an ID code of
its own
to a base station through an access channel to request the charging data
service,
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detecting a second charging data channel information on the
common channel, sending a charging data service request
confirm message to the base station on the access channel,
and receiving the specified charging data on the
corresponding charging data channels assigned thereto.
To achieve the above objects, there is provided a
method for providing a data service in a CDMA communications
system comprising the steps of: (a) sending, at a base
station, first charging data channel information to a
plurality of mobile stations on a common channel; (b)
receiving, at the base station, a charging data service
request message from a specified mobile station; (c)
assigning, at the base station, charging data channels and
sending second charging data channel information to the
mobile station on the common channel; and (d) sending, at
the base station, specified charging data to the mobile
station on the charging data channels upon receiving a
service request confirm message from the mobile station.
According to another aspect of the present
invention, there is provided a method for providing a data
service in a CDMA communications system comprising the steps
of: (a) demodulating, at a mobile station, first charging
data channel information on a common channel; (b) sending,
at the mobile station, a type of charging data desired and
an ID code of its own to a base station on an access channel
and sending a charging data service request message to the
base station; (c) detecting, at the mobile station, second
charging data channel information on the common channel and
sending a charging data service request confirm message to
the base station; and (d) receiving, at the mobile station,
specified charging data on charging data channels assigned.
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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
5 in conjunction with the accompanying drawings in which like
reference numerals indicate like parts. In the drawings:
FIG. 1 is a diagram illustrating a procedure of
providing a free data service between a base station and a
plurality of mobile stations in accordance with an
embodiment of the present invention; and
FIG. 2 is a diagram illustrating a procedure of
providing a charging data service between the base station
and the mobile stations in accordance with the embodiment of
the present invention.
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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, to provide a free data
seivice, a base station assigns a predetermined number of channels on which
free data
will be transmitted, and sends the free data to a plurality of mobile stations
through
the free data channels assigned. The base station also sends information about
free
data channels to the plural mobile stations through a common channel. Here,
the
common channel may be a paging channel.
To be served with the free data service, the individual mobile station
demodulates a[paging] common channel received from the base station to detect
information about the free data channels. The free data channel information
includes
oi-thogonal codes used for the corresponding free data channels, the type and
the
number of the free data, and continuous transmit information or time-division
ti-ansmit information, etc. When the continuous transmit information is
included in
the free data channel information, it may be understood that the free data is
transmitted continuously by the frame unit. With the time-division transmit
information included in the free data channel information, the free data is
transmitted
by the frame unit that is divided into time slots of the multiple mobile
stations. Here,
the time-division transmit information may include the number of the time
slots for
the frame unit and the time-division period. The channel on which the free
data is
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transmitted may be a fundamental channel.
Referring to FIG. 1, there is shown a diagram illustrating a procedure of
providing a free data service between a base station and a plurality of mobile
stations
in accordance with the embodiment of the present invention.
The base station sends free data channel information to each individual mobile
station on a [paging] common channel and also sends free data to the multiple
mobile
stations on the free data channels.
The individual mobile station detects the free data channel information from
the [paging] common channel and, according to the detected information,
demodulates the free data channels to receive the free data.
In the preferred embodiment of the present invention, to provide a charging
data service, the base station assigns a predetermined number of channels on
which
charging data will be transmitted. The base station sends first charging data
channel
information to a plurality of mobile stations, through a paging channel. The
first
charging data channel information may be information used to select the type
of
desired charging data. At this time, the base station and the mobile stations
that desire
the charging data service start to perform channel negotiation so that the
base station
assigns charging data channels to the mobile stations.
To be served with the charging data service, the individual mobile station
deinodulates the common channel received from the base station to detect the
first
cliarging data channel information. The common channel may be a paging
channel.
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Then, the mobile station sends the type of the charging data to be served and
an ID
code to the base station through an access channel to order the charging data
service.
The ID code may be an ID number of the specified mobile station or an
international
mobile station ID number.
Upon receiving a charging data service request message from the specified
mobile station, the base station sends second charging data channel
information to the
mobile station through the common channel. The common channel may be a paging
channel. Then, the mobile station demodulates the common channel received from
the base station to detect the second charging data channel information. The
second
charging data channel information includes orthogonal codes corresponding to
the
type of the charging data to be served, continuous transmit information or
time-
division transmit information, the password for the ID code of the mobile
station
i-equesting the charging data service, and a start point of the corresponding
time slot,
etc. Here, the password is used by the base station to encrypt the charging
data lest
other users should have access to the charging data intentionally.
If the continuous transmit infon-nation is included in the second charging
data
channel information, it may be understood that the charging data is
transmitted
continuously by the frame unit. With the time-division transmit information
included
in the second charging data channel inforrriation, the charging data is
transmitted by
the frame unit that is divided into time slots of the multiple mobile
stations. Here, the
time-division transmit information may include the number of the time slots
for the
frame unit and the time-division period.
Upon receiving the second charging data channel information from the base
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station, the individual mobile station sends a service request confirm message
to the
base station through an access channel. In response to the service request
confirm
niessage, the base station sends the desired charging data to the mobile
station on the
corresponding forward link charging data channel. When receiving the charging
data,
the niobile station sends billing information for the charging data or a
charging data
sei-vice ending request message to the base station through the corresponding
reverse
link charging data channel.
If the charging data is transmitted continuously, the mobile station sends
billing information to the base station on the reverse link charging data
channel every
time it receives the charging data by the frame unit. Here, the billing
information
includes a password for the ID code and a continued-service request message.
If the
charging data is transmitted on a time-division basis, the mobile station
sends the
billing information inclusive of the password for the ID code and the
continued-
seivice request message to the base station on the reverse link charging data
channel
at the start point of the time slots of its' own.
The base station interrupts the charging data service immediately when it
fails
to receive the billing information or receives the service ending request
message from
the mobile station. The base station also sends a charging data service ending
message to the mobile station on the forward link charging data channel and
ending
the charging data service. The channel on which the charging data are
transmitted
niay be a fundamental channel or a supplemental channel or a dedicated control
channel.
Referring now to FIG. 2, there is shown a diagram illustrating a procedure of
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pi-oviding a charging data service communicated between a base station and a
plurality of mobile stations in accordance with the embodiment of the present
invention.
The base station sends first charging data channel information to each
individual mobile station through a common channel, in step 211. The common
channel may be a paging channel. The first charging data channel information
may
be information used to select the type of charging data available. The base
station
assigns orthogonal codes to the corresponding charging data channel. Here, the
] 0 cliarging data channel established between the base station and the
individual mobile
station is a bidirectional dedicated channel.
In step 213, the mobile station concerned demodulates the paging channel
i-eceived from the base station to detect the first charging data channel
information.
] 5 Then, the mobile station sends the type of the charging data to be served
and an ID
code of its own to the base station through an access channel to order a
charging data
service.
Upon receiving a charging data service request message from the specified
20 niobile station, in step 215, the base station assigns orthogonal codes to
the
corresponding forward and reverse link charging data channels. And, the base
station
sends second charging data channel information to the mobile station through
the
common channel. For the second charging data channel information, there may be
included orthogonal codes corresponding to the type of the charging data to be
25 sei-ved, continuous transmit information or time-division transmit
information, the
password for the ID code, and a start point of the corresponding time slot,
etc.
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In step 217, the mobile station demodulates the common channel received
fi-om the base station to detect the second charging data channel information.
Then,
the mobile station sends a charging data service request confirm message to
the base
station on the access channei.
Upon receiving the charging data service request confirm message from the
mobile station; the base station sends the charging data to the mobile station
on the
coi-responding forward link charging data channel and providing the charging
data
service, in step 219.
When receiving the charging data from the base station, the mobile station
sends billing information for the charging data on the corresponding reverse
link
charging data channel in step 221, or sends a charging data service ending
request
message to the base station in step 223. Thereafter, the procedures of steps
219 and
221 ai-e repeatedly performed.
When the base station fails to receive the billing information or receives the
charging data service ending request message, it sends a charging data service
ending
confin-n message to the mobile station on the forward link charging data
channel and
interrupts the charging data service, in step 225.
As stated above, the base station provides free data to the multiple mobile
stations on the free data channel in an efficient manner. This allows a number
of
subscribers to be served with the free data of small quantity, such as daily
weather
and stock information, etc., at any time.
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In a case where the data service is charging data of large quantity, such as
Internet service and the like, the base station assigns a predetermined number
of
charging data channels only to the mobile stations that request the charging
data
sei-vice, and sending the charging data service to the mobile stations through
the
cliarging data channels. Then, the mobile stations sends billing information
for the
cliarging data service to the base station on the reverse link charging data
channels.
As described above, for a free data service, the base station sends free data
cliannel information on the common channel and transmitting free data on the
free
data channels. For a charging data service, the base station sends charging
data
channel information to the mobile stations, assigning the charging data
channels and
sending the charging data to the mobile stations that desire the charging data
service.
Accordingly, the present invention has an advantage in regard to efficient
channel
assignment and data service.
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
vai-ious 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.