Title: Navigation system using a paging channel and a method for providing traffic information
Abstract: A navigation system utilizing a paging channel of a mobile communication service for a navigation apparatus including a mobile communication function is disclosed, which comprises: a BSC-based traffic server for periodically extracting/synthesizing traffic information in an area of a BSC, and then transmitting the traffic information of a peripheral area including the BSC; and a BSC for inserting the traffic information received from the BSC-based traffic server into the paging channel for a mobile communication terminal, and then transmitting it. In the navigation system, traffic conditions information in a corresponding area is transmitted by means of a paging channel, thereby utilizing real time traffic information while maintaining the architecture of the existing mobile communication network without an additional apparatus and communication cost.
Patent Number: 6,898,515 Issued on 05/24/2005 to Kim, et al.
| Inventors:
|
Kim; Jin-Won (Seoul, KR);
Chun; Kyong-Joon (Seoul, KR);
Lee; Yoon-Deock (Seoul, KR);
Kum; Dong-Jun (Anyang-shi, KR);
Choi; Sun (Seoul, KR)
|
| Assignee:
|
Samsung Electronics Co., Ltd. (KR)
|
| Appl. No.:
|
653637 |
| Filed:
|
September 2, 2003 |
Foreign Application Priority Data
| Jan 11, 2003[KR] | 10-2003-0001873 |
| Current U.S. Class: |
701/201; 701/117; 701/210 |
| Intern'l Class: |
G08G 001/09.68; G01C021/20 |
| Field of Search: |
701/202,201,209,210,117,118,119
340/995.13,995.19
|
References Cited [Referenced By]
U.S. Patent Documents
| 5809424 | Sep., 1998 | Eizenhoefer.
| |
| 5933100 | Aug., 1999 | Golding.
| |
| 6216085 | Apr., 2001 | Emmerink et al.
| |
| 6351647 | Feb., 2002 | Gustafsson.
| |
| 6421602 | Jul., 2002 | Bullock et al.
| |
| 6526349 | Feb., 2003 | Bullock et al.
| |
| 6532418 | Mar., 2003 | Chun et al.
| |
| 6535743 | Mar., 2003 | Kennedy et al.
| |
| 6757609 | Jun., 2004 | Tsuge et al.
| |
| 6807483 | Oct., 2004 | Chao et al.
| |
Primary Examiner: Zanelli; Michael J.
Attorney, Agent or Firm: Dilworth & Barrese, LLP
Claims
1. A navigation system utilizing a paging channel of a mobile communication service
for a navigation apparatus including a mobile communication function, the navigation
system comprising:
a BSC-based traffic server for periodically extracting/synthesizing traffic information
in an area of a BSC and then transmitting the traffic information in the area which
is controlled by the BSC; and
a BSC for inserting the traffic information received from the BSC-based traffic
server into the paging channel for a mobile communication terminal and then transmitting
the paging channel.
2. The navigation system as claimed in claim 1, wherein the traffic information
is information in which an average travel speed of all links in the area of the
BSC, which is divided into nodes and links between respective nodes, is extracted
and synthesized.
3. The navigation system as claimed in claim 1, wherein the paging channel for
the mobile communication terminal includes a field representing paging channel
information for a general mobile communication and a traffic information field
including a Stt_Message representing a start of the traffic information, a Info_Message
representing the traffic information and an End_Message representing an end of
the traffic information.
4. The navigation system as claimed in claim 3, wherein the Stt_Message includes
a Message Begin field for informing a start of a message, a BSC ID field, an area
code field for an area which is controlled by a corresponding BSC, a Time Index
field for storing collection time information of corresponding traffic information
and a node number field for storing the number of nodes in a corresponding area.
5. The navigation system as claimed in claim 3, wherein the Info_message exists
as many as the number of nodes in the BSC area and includes a Node Begin field
for informing a start of a node, a Node ID field, an adjacent link number field
of a corresponding node, an adjacent link ID field for all links adjacent to a
corresponding node and an average travel speed field in a corresponding link.
6. The navigation system as claimed in claim 3, wherein the End_message includes
an End_M Begin field for informing a start of an End_message and a Message End
field for informing an end of a message.
7. A navigation apparatus including a mobile communication function for a navigation
system utilizing a paging channel of a mobile communication service, the navigation
apparatus including a mobile communication function comprising:
a paging channel analyzing means for analyzing a paging channel transmitted from
a BTS and determining whether the navigation apparatus has entered a new BSC area
or whether traffic information has been upgraded;
a decoding means for decoding the traffic information included in the paging
channel for any one of a case in which the navigation terminal has entered the
new BSC area and a case in which the traffic information has been upgraded, on
the basis of the analysis result of the paging channel analyzing means; and
an optimal path calculation means for calculating an optimal path by means of
the traffic information decoded by the decoding means.
8. The navigation apparatus as claimed in claim 7, wherein the optimal path calculation
means calculates the optimal path according to links in a BSC by means of the traffic
information, thereby providing the calculated optimal path.
9. The navigation apparatus as claimed in claim 7, wherein the optimal path calculation
means determines a degree of congestion of traffic on a current path by means of
the traffic information, and determines whether there exists an avoidance region
which has an average speed below a predetermined speed set in advance, thereby
providing an optimal path.
10. A method for searching for an optimal path in real time by means of a navigation
system utilizing a paging channel of a mobile communication service, the method
comprising the steps of:
(1) receiving entire optimal path information for a starting point and a destination
and storing the entire optimal path information;
(2) receiving paging signals through a BTS, analyzing the paging signals, extracting
traffic information included in the paging signals, and then storing the extracted
information;
(3) when the extracted traffic information is updated traffic information, calculating
an optimal path in a corresponding BSC area by means of the updated traffic information;
and
(4) replacing a corresponding part of the optimal path in step (1) with the optimal
path in step (3), and then storing the replaced optimal path.
11. The method as claimed in claim 10, wherein step (3) comprises:
(3-1) determining a target node in the corresponding BSC area; and
(3-2) searching for a partial optimal path to the target node by means of the
traffic information.
12. The method as claimed in claim 10, wherein step (3) comprises:
(3-1) determining a target node in the corresponding BSC area;
(3-2) confirming whether an avoidance region, which has an average speed below
a predetermined speed set in advance, exists in the optimal path stored in step
(1); and
(3-3) as a result of confirmation in step (3-2), searching for a partial optimal
path to the target node when the avoidance region exists, and employing the optimal
path, which has been stored in step 1, as the partial optimal path to the target
node when the avoidance region does not exist.
13. A computer-processible recording medium employed in a navigation system having
a processor, the recording medium containing a program, the program comprising
the following functions of:
(1) receiving entire optimal path information for a starting point and a destination
and storing the entire optimal path information;
(2) receiving paging signals from a BTS, analyzing the paging signals, extracting
traffic information included in the paging signals, and then storing the extracted
information;
(3) when the extracted traffic information is updated traffic information, calculating
an optimal path in a corresponding BSC area by means of the updated traffic information;
and
(4) replacing a corresponding part of the entire optimal path with the optimal
path in the corresponding BSC and then storing the replaced optimal path.
Description
PRIORITY
This application claims priority to an application entitled "Navigation System
Using Paging Channel And Method For Providing Traffic Information" filed in the
Korean Industrial Property Office on Jan. 11, 2003 and assigned Serial No. 2003-1873,
the contents of which are hereby incorporated by reference.
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a navigation system, and more specifically to
a navigation system for transmitting real time traffic information by means of
a paging channel and searching for an optimal path, in real time, by means of the
real time traffic information and a method for providing the traffic information.
2. Description of the Related Art
In general, positional information regarding movable bodies, such as ships, airplanes
and vehicles, may be provided to navigation systems. The global positioning system
(GPS) position measuring device receives radio signals representing a latitude,
a longitude and an altitude, etc., from a plurality of satellites included in the
GPS and calculates current positions of movable bodies. Further, the GPS position
measuring device displays geographical information, including current positions,
on the basis of map data stored in advance. That is, a general navigation system
(GNS) provides drivers with various information, necessary for driving, by means
of information received from the GPS. For instance, the GNS displays on a screen
a current speed of movement, a path of movement set by a driver before driving,
and an optimal path to a destination.
Core technologies of a navigation system include a positioning technology for
accurately determining a position of the movable bodies and a routing technology
for informing a path to a destination. The present invention addresses the latter.
In general, a routing is performed by means of a digital map DB, a current position
of the movable body and destination information. For the routing, algorithms, such
as, a digital Dijkstra algorithm or A* algorithm are utilized.
In order to improve the precision of a routing result of such navigation system,
traffic information must be included in the algorithm. Furthermore, when it is
considered that the traffic information continuously changes, a continuous update
for the traffic information must be performed during the travel of a vehicle.
In general, when a vehicle driver wants a routing that reflects traffic information,
the vehicle driver should access a traffic information management server. For example,
a connection to the traffic information management server must be performed before
the vehicle driver starts toward destination, or according to the needs of a user
during traveling of a vehicle, a reconnection to a traffic information management
server must be performed, and a path must be received.
FIG. 1 is a block diagram of a navigation system for providing traffic information
in a conventional way. In order to utilize real time traffic information during
traveling, a navigation terminal 10 must be connected to a traffic server
20. The traffic server 20 obtains traffic information regarding a
requested area from a traffic information database (DB) 25 and then provides
it to the navigation terminal 10. However, according to this method, in
order to provide real time traffic information, a connection between the navigation
terminal 10 and the traffic server 20 must be performed. Accordingly,
in a case in which path guidance data reflecting traffic information, from an original
starting point to a destination, is received and then path guidance is performed
by means of the path guidance data, a target road may not have been congested when
an original path was actually calculated. However, when a vehicle moves and enters
into the target road, severe congestion may have occurred due to change of traffic
conditions. To avoid this situation, path guidance data including new traffic information
must be received after connecting to the traffic server each time. Accordingly,
a traffic information user must bear not only DB charges but also an additional
communication cost of utilizing the DB.
Other technologies for transmitting traffic information by means of frequency
modulation (FM) additional broadcasting have been developed. However, according
to this method, since traffic information of a particular avoidance region or a
wide area is transmitted, but traffic information of an area in which a user is
driving at present is not transmitted, it is difficult to apply a real time optimal
path search by means of traffic information updated with rapid period.
Furthermore, according to the conventional methods using the FM additional
broadcasting, additional apparatus for receiving FM additional carrier must be
installed. That is, in addition to a portable terminal generally used in navigation
or a universal mobile communication means such as a communication module, additional
hardware is necessary.
Moreover, in the navigation terminal using traffic information transmitted
through the FM additional broadcasting, a real time path calculation can not be
performed and only simple text messages are displayed. Accordingly, a driver must
see the text messages during traveling, in order to determine and avoid congestion
areas, which may be very detrimental to the driver's safety.
SUMMARY OF THE INVENTION
Accordingly, the present invention has been made to solve the above-mentioned
problems occurring in the prior art, and it is an object of the present invention
to provide a navigation system for searching for an optimal path by means of real
time traffic information.
It is another object of the present invention to provide a navigation system
capable
of collecting real time traffic information without additional cost and maximizing
a routing effect by means of collected traffic information.
It is another object of the present invention to provide a navigation apparatus
for transmitting real time traffic information by means of a paging channel utilized
in a wireless network and searching for an optimal path in real time by means of
the real time traffic information and a method for providing the traffic information.
In order to accomplish these objects according to the preferred embodiment of
the present invention, there is provided a navigation system utilizing a paging
channel of a mobile communication service for a navigation apparatus including
a mobile communication function comprising: a base station controller (BSC)-based
traffic server for periodically extracting/synthesizing traffic information in
an area of the BSC from a traffic information management center which provides
a navigation service and manages traffic information for an entire path and then
transmitting the traffic information in the area which is controlled by the BSC;
and the BSC for inserting traffic information received from the BSC-based traffic
server into the paging channel for a mobile communication terminal and then transmitting
the paging channel.
In order to accomplish these objects according to the preferred embodiment of
the present invention, there is provided a navigation apparatus including a mobile
communication function for a navigation system utilizing paging channel of a mobile
communication service, the navigation apparatus including a mobile communication
function comprising: a paging channel analyzing means for analyzing paging channel
transmitted from a base transceiver station (BTS) and determining whether the navigation
apparatus has entered a new BSC area or not or whether traffic information has
been upgraded or not; a decoding means for decoding the traffic information included
in the paging channel for any one of a case in Which the navigation terminal has
entered the new BSC area and a case in which the traffic information has been upgraded,
on the basis of the analysis result of the paging channel analyzing means; and
an optimal path calculation means for calculating an optimal path by means of the
traffic information decoded by the decoding means.
In order to accomplish these objects according to the preferred embodiment of
the present invention, there is provided a method for searching for an optimal
path in real time by mean of a navigation system utilizing paging channel of the
mobile communication service comprising the steps of: (1) receiving entire optimal
path information for a starting point and a destination and storing the entire
optimal path information; (2) receiving paging signals through a BTS, analyzing
the paging signals, extracting traffic information included in the paging signals
and then storing the extracted information; (3) calculating an optimal path in
a corresponding BSC area by means of the extracted traffic information; and (4)
when two optimal paths are different from each other after comparing the optimal
path in step (3) with the optimal path in step (1), replacing a corresponding part
of the optimal path in step (1) with the optimal path in step (3) and then storing
the replaced optimal path.
In order to accomplish these objects according to the preferred embodiment of
the present invention, there is provided a computer-processable recording medium
employed in a navigation system having a processor, the recording medium containing
a program comprising the following functions of: (1) receiving entire optimal path
information for a starting point and a destination and storing the entire optimal
path information; (2) receiving paging signals from a BTS, analyzing the paging
signals, extracting traffic information included in the paging signals, and then
storing the extracted information; (3) calculating an optimal path in a corresponding
BSC area by means of the extracted traffic information; and (4) when two optimal
paths are different from each other after comparing the optimal path in step (3)
with the optimal path in step (1), replacing a corresponding part of the entire
optimal path with the optimal path in the corresponding BSC, and then storing the
replaced optimal path.
BRIEF DESCRIPTION OF THE DRAWINGS
The above and other objects, features and advantages of the present invention
will be more apparent from the following detailed description taken in conjunction
with the accompanying drawings, in which:
FIG. 1 is a block diagram showing a construction of a navigation system for
providing traffic information in a conventional way;
FIG. 2 is a block diagram of one embodiment of a navigation system for providing
traffic information by means of a paging channel according to the present invention;
FIG. 2
a is an exemplary view of a structure of a database included in
the BSC-based traffic server for managing the traffic information according to
the present invention;
FIG. 2
b is an exemplary view of a paging message packet for transmitting
traffic information according to one embodiment of the present invention;
FIG. 2
c is an exemplary view of a detailed structure of traffic information
included in a paging packet according to the present invention;
FIG. 3 is a block diagram of one embodiment of a navigation terminal according
to the present invention;
FIG. 4 is a block diagram of a real time traffic information processing section
of a navigation terminal of the present invention;
FIG. 5 is a flow chart of a first embodiment of a method for searching for a
path in real time in a navigation terminal according to the present invention;
FIG. 6 is a flow chart of a second embodiment of a method for searching for
a path in real time in a navigation terminal according to the present invention; and
FIG. 7 is an exemplary view of links and nodes in a BSC according to the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
Hereinafter, according to preferred embodiment of the present invention
will be described with reference to the accompanying drawings. In the following
description and drawings, the same reference numerals are used to designate the
same components. In the following description of the present invention, a detailed
description of known functions and configurations incorporated herein will be omitted
when it may make the subject matter of the present invention rather unclear.
FIG. 2 illustrates one embodiment of a navigation system for providing traffic
information by means of a paging channel, including a navigation terminal
500
having communication function for receiving navigation services, base transceiver
stations (BTSs), BTS #
1 to BTS #N
400 for providing the navigation
terminal
500 with information, a base station controller (BSC)
300
for managing the BTSs
400, a BSC-based traffic server
200 for managing
traffic information according to the BSC
300 and a central traffic server
100 for periodically extracting traffic information in an area of each BSC
300. The inventive navigation system synthesizes the extracted information
and then transmits the synthesized information to respective BSC-based traffic
server
200. The BSC-based traffic server
200 may directly collect/manage
traffic information of an area without receiving traffic information of the area,
which is controlled by the BSC-based traffic server
200 from the central
traffic server
100.
The entire operation of the navigation system is described below. The BSC-based
traffic server
200 extracts traffic information in an area of the BSC
300
from traffic information transmitted from the central traffic server
100
and synthesizes the extracted information. Then, the BSC-based traffic server
200
transmits traffic information in a peripheral area including a corresponding BSC
300 to the BTSs
400 via the BSC
300. Herein, the BSC
300
includes the transmitted information into a paging channel for mobile terminals
and then transmits the paging channel to the BTSs
400.
The BTSs
400 transmits traffic information of a corresponding area, received
periodically through paging channel for terminals in a corresponding BTS
400,
to the navigation terminal
500. The navigation terminal
500, which
has a mobile communication means, decodes the traffic information transmitted through
the paging channel and then determines a degree of congestion of traffic on a current
path. The navigation terminal
500 recalculates an optimal path and then
provides navigation information in which real time traffic information is included.
Herein, a statement "the BSC-based traffic server
200 periodically
extracts traffic information in an area of the respective BSC
300 and then-synthesizes
the extracted information" implies that the BSC-based traffic server
200
extracts an average travel speeds of all links in the area of the respective BSC
300 and then synthesizes the extracted speed. FIG. 7 illustrates links and
nodes in a BSC in view of a map in the area, which is controlled by the BSC
300,
comprises a plurality of links and nodes, paths of the present invention are searched
through these links and nodes. Particularly, in FIG. 7, nodes S, and E marked by
a quadrangle, represent a starting point S and an ending point E in a corresponding
area. Parts L
1 to L
8 marked by a thick line represent paths searched
as an optimal path from the starting point S and the ending point E. From among
the paths, path L
3 marked by a thick broken line represents a path which
has been initially found as an optimal path, but which has been canceled on the
basis of traffic information according to the BSC
300 (FIG.
2). That
is, in an example of FIG. 7, an optimal path from a starting point S to an ending
point E has been selected in a sequence of L
1, L
2, and L
3,
while the part L
3 is determined as a congestion area on the basis of traffic
information according to the BSC. Then, an optimal path excluding the path L
3
is again searched. As a result of the search, the optimal path from the starting
point S to the ending point E is selected in a sequence of L
1, L
2,
L
4, L
5, L
6, L
7, and L
8.
According to the present invention, in contrast with a conventional navigation
reflecting traffic information by means of only the central traffic server
100,
traffic information servers according to corresponding areas are provided at the
respective BSC
300 in mobile communication service system, and real time
traffic information according to areas are transmitted. An example of a database
structure
210, included in the BSC-based traffic server
200, for
managing the traffic information according to the BSC is shown in FIG. 2
a.
In consideration of the traffic information managed by the BSC-based traffic
server
200 with reference to FIG. 2
a, the traffic information managed by
the BSC-based traffic server
200 includes an identifier (ID)
211
of a corresponding BSC
300, an area code
212 of the corresponding
BSC
300, adjacent links
213 according to nodes included in the corresponding
BSC
300, speeds
214 according to links included in the corresponding
BSC
300 and time information Time Index
215 collecting corresponding
traffic information.
In order to transmit the traffic information in the corresponding BSC
300
area, managed as described above to the navigation terminal
500 having communication
function, paging packet shown in FIG. 2
b is utilized. That is, a traffic
information
230 field is included in a field representing a general paging
channel information
220. The traffic information field includes an Stt_Message
representing a start of the traffic information, an Info_Message representing the
traffic information, and an End_Message representing an end of traffic information.
When paging is performed, the paging packet is transmitted by the navigation terminal
500 having communication function.
A detailed structure of the Stt_message
231, Info_message
232,
and
End_message
233 included in the traffic information field
230 is
shown in FIG. 2
c. As shown, the Stt_message (a) includes a Message Begin
field for informing a start of a message, a BSC ID field, an area code field for
an area which is controlled by a corresponding BSC, a Time Index field for storing
collection time information of corresponding traffic information and a node number
field for storing the number of nodes in a corresponding area.
The Info_message (b) includes as many rows as the number of nodes in a BSC area
and includes a Node Begin field for informing a start of a node, a Node ID field,
an adjacent link number field of a corresponding node. Further, the Info_message
(b) includes a link ID field of each adjacent link in accordance with the number
of a corresponding link of the adjacent link number field and an average travel
speed field in an adjacent link. Herein, the Info_message (b) may further include
a BSC ID field and a Time Index field for storing collection time information of
corresponding traffic information, thereby determining the BSC area to which the
received traffic information belongs and determining time information in which
the traffic information has been generated, even if the corresponding traffic information
has been received from the middle of the corresponding traffic information.
The End_message (c) includes an End_M Begin field for informing a start of an
End_message and a Message End field for informing an end of a message.
FIG. 3 shows one embodiment of a navigation terminal according to the present
invention. The navigation terminal according to the present invention includes
a user interface section
510, a display section
520, a map matching
section
530, a sensor section
540, a path guiding section
550,
a data transceiving section
560, a format processing section
570,
a real time traffic information processing section
580, and a memory
590.
In order to receive path guidance, the user inputs user requirements, such as
selecting a navigation function mode, and setting a current position and a destination
in the navigation function mode, through the user interface section
510.
The display section
520 displays a map, a destination and a path, etc.,
in accordance with performance of navigation functions. The data transceiving section
560 generates/transmits signals suitable for a wireless network and receives
signal from the wireless network. The format processing section
570 converts
data into a format set in advance in agreement with a traffic server, which manages
a wireless network and traffic information. The format processing section
570
interprets signals received in the data transceiving section
560 according
to the promised format and converts the interpreted signals into data. The path
guiding section
550 processes path guidance data for performing path guidance
function. The sensor section
540 extracts various data necessary in understanding
a current position of a necessary vehicle for navigation function.
The map matching section
530 displays a current position of a moving vehicle
at a corresponding point on a map. The map matching section
530 compares
the path guidance data received from the traffic server with position data received
in the sensor section
540, thereby understanding a movement state of a vehicle
at a current point. The real time traffic information processing section
580
analyzes the traffic information transmitted from the BSC, thereby searching real
time optimal paths for a corresponding BSC area.
FIG. 4 is a block diagram showing a detailed construction of a real time traffic
information processing section
580 of a navigation terminal according to
the present invention. The real time traffic information processing section
580
includes a paging channel analyzing section
581, a decoding section
582,
and a path searching section
583. The paging channel analyzing section
581
analyzes a paging channel transmitted from a BTS and then divides it into paging
information and traffic information. Further, the paging channel analyzing section
581 determines whether the navigation terminal has entered a new BSC area
or not or whether the traffic information has been upgraded or not. The decoding
section
582 decodes the traffic information included in the paging channel
for any case in which the navigation terminal have entered the new BSC area and
a case in which the traffic information has been upgraded, on the basis of the
analysis result of the paging channel analyzing section
581 and then stores
the decoded information in the memory
590. The path searching section
583
searches an optimal path by means of the traffic information stored in the memory
590 and the traffic information decoded by the decoding section
582
and then transmits the search result to the memory
590.
FIG. 5 is a flow chart illustrating a first embodiment of a method for searching
for a path in real time in a navigation terminal according to the present invention.
First, an optimal path received from a central traffic server is stored in step
S
110. Herein, the optimal path implies the entire optimal path including
traffic information from a starting point to a destination when an original path
is calculated. The navigation terminal performs path guidance by means of the stored
optimal path. Further, a paging channel message, which is basically provided by
communication modules or portable terminals of a mobile communication service,
are received in step S
120. Then, the paging channel message is analyzed
in step S
130 and then traffic information message included in the paging
channel message is extracted in step S
130. Herein, the traffic information
message is included in the paging channel received through a BTS from a BSC. The
traffic information included in the paging channel message is decoded and then
is stored in step S
140.
BSC IDs included in the paging channel message are compared with each other,
so that whether or not a navigation terminal has entered an area controlled by
a new BSC is determined in step S
150. As a result of the determination in
step S
150, when the navigational terminal has not entered the area controlled
by a new BSC, whether or not the traffic information has been newly updated is
first determined by means of a Time index in step S
160. For instance, when
the Time index information has changed, it is determined that the traffic information
has been newly updated.
When the navigational terminal has entered the new area in step S
150,
or when the traffic information has been updated in step S
160, target nodes
in a corresponding BSC area are determined on the basis of path information already
stored in a memory in step S
170, and an optimal path from a current position
to the target nodes is calculated by means of the traffic information in step S
180.
Herein, the optimal path is a partial optimal path different from the optimal path
in step S
110.
Next, whether or not the partial optimal path in step S
180 is agreed
with the entire optimal path already stored in the memory in step S
110 is
determined in step S
190. As a result of the determination in step S
190,
when the partial optimal path is not agreed with the entire optimal path, the newly
calculated optimal path is stored in the memory in step S
200 and then the
new path is provided to a user in step S
210. When the partial optimal path
is agreed with the entire optimal path, step S
120 is performed. Herein,
it is self-evident that the optimal path information stored in the memory may be
a partial optimal path before the traffic information has been updated. Further
in step S
220, the paging channel message is continually received until the
user arrives at an initially set destination, thereby repeating then steps S
120
to S
210.
FIG. 6 is a flow chart illustrating a second embodiment of a method for searching
for a path in real time in a navigation terminal according to the present invention.
First, an optimal path received from a central traffic server is stored in step
S
310. Herein, the optimal path implies an entire optimal path from a starting
point to a destination. Further, paging channel message, which is basically provided
by communication modules or portable terminals of a mobile communication service,
are received in step S
320. The paging channel message is analyzed in step
S
330 and then traffic information message included in the paging channel
message is extracted in step S
330. Herein, the traffic information message
is included in the paging channel received through a BTS from a BSC. The traffic
information included in the paging channel message is decoded and stored in step S
340.
BSC IDs included in the paging channel message are compared with each other,
so that whether or not a navigation terminal has entered an area controlled by
a new BSC is determined in step S
350. As a result of the determination in
step S
350, when it has not entered the area controlled by a new BSC, whether
or not the traffic information has been newly updated is first determined by means
of a Time index in step S
360. Further, when it has entered the new area
in step S
350 or when the traffic information has been updated in step S
360,
an avoidance region in a corresponding BSC area, which is a link having an average
travel speed below a congestion determination speed defined in advance, is detected
and stored in step S
370. Herein, the criterion for an avoidance region may
be an average travel speed as described above, but when the traffic information
includes information regarding the kinds of road and road width, the criterion
for an avoidance region may be a result generated by combining the kinds of road,
the road width and the average travel speed. That is, when the result generated
by combining the kinds of road, the road width and the average travel speed does
not meet a criterion set in advance, it may be judged as an avoidance region.
Target nodes in a corresponding BSC area are determined on the basis of path
information already stored in a memory in step S
380, and then whether or
not an avoidance region is included in the optimal path stored in step S
310
is confirmed in step S
390. As a result of the confirmation in step S
390,
when an avoidance region is not included in the optimal path stored in step S
310,
step
320 is performed. Also, when the avoidance region is included in the
optimal path stored in step S
310, an optimal path to a destination in a
BSC excluding an avoidance region is searched by means of the traffic information
in step S
400. Herein, the optimal path is a partial optimal path different
from the optimal path in step S
310. The newly searched partial optimal path
is stored in the memory in step S
410 and then the partial optimal path is
provided to a user in step S
420. Further on step S
430, the paging
channel message is continually received until the user arrives at an initially
set destination, thereby repeating the steps S
320 to S
420.
However, when a path search is always performed by means of real time traffic
information, it may be sometimes impossible to perform corresponding steps according
to performance of a navigation terminal. In this case, the second embodiment of
the present invention employs a congestion area avoiding path search algorithm,
which can exclude only links, each having an average travel speed below a congestion
determination speed defined in advance.
The method of the present invention as described above can be implemented in
software and then stored in recording media, such as a CD ROM, a RAM, a floppy
disk, a hard disk, and a magneto-optical disk in a computer-processable type.
According to the present invention as described above, traffic conditions
in an area in which a vehicle is driving are understood in real time and then are
applied for path search, thereby maximizing a routing effect of a navigation system.
Particularly, traffic conditions in a corresponding area are transmitted by means
of paging channel, thereby utilizing real time traffic information while maintaining
the architecture of the existing mobile communication network without an additional
apparatus and communication cost. Further, an optimal path to a destination is
recalculated on the basis of the real time traffic information and then is provided
to users, thereby maximizing navigation functions.
While the invention has been shown and described with reference to certain
preferred embodiments 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.
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