KR101588195B1 - Apparatus for channel congestion avoidance of device driver and method thereof - Google Patents

Abstract

The present invention relates to a device for avoiding channel congestion and a method for avoiding channel congestion based on received signal strength (RSSI) and surrounding wireless environment information acquired through an access point (AP) An access point (AP) connected to a base station for relaying wireless communication to perform channel search, and generating and providing a channel list for avoiding channel congestion based on the channel search result and the acquired wireless environment information; And a driver terminal for changing a channel based on a channel list provided by the access point when a channel is changed. The access point searches for a channel by accessing the base station, extracts a received signal strength for the search channel, A channel search unit; A radio environment information obtaining unit for obtaining radio environment information on the search channel; And a channel list generation unit for generating a channel list for avoiding channel congestion based on the received signal strength of the channel searched by the channel search unit and the radio environment information acquired by the radio environment information acquisition unit.

Description

[0001] The present invention relates to an apparatus and method for avoiding channel congestion of a driver terminal,

The present invention relates to an apparatus and method for avoiding channel congestion in a driver terminal, and more particularly to a system and method for avoiding channel congestion based on received signal strength (RSSI) and surrounding wireless environment information acquired through an access point The present invention relates to a channel congestion avoiding apparatus and method for a driver terminal capable of transmission.

Generally, a bus is equipped with a boarding and landing terminal for reading a card of a passenger (usually, the boarding terminal is located at a bus riding position and the getting-off terminal is located at a bus riding position) A driver terminal for transferring bus driving information via a bus or transmitting card information of a passenger in real time.

The driver terminal mounted on the bus stores the contents of the transaction every time a fee is collected from the transportation card of the passenger, and transmits the transaction contents to the settlement server (management server) through a wireless LAN or a RAM pack. The contents are settled by each bus and transportation company.

In addition, the driver terminal records bus operation information, wirelessly communicates with the management server periodically or in real time, transmits bus operation information, and receives and stores information necessary for bus operation. Here, the driver terminal usually uses wireless communication using the 2.4G band.

An important consideration when using wireless communication on the bus is that high-speed data transmission should always be done in real time. Here, the high-speed data transmission means that the signal strength indicating sensitivity is -60 dBm or more, the wireless speed is 24 Mbps, and the data transmission speed is 10 Mbps.

To this end, in a general driver terminal, the RSSI of the occupied channel is searched in real time, and if the received signal strength is lower than a predetermined intensity, the channel is immediately changed to another channel. At this time, it takes a considerable time to change the channel, and communication is interrupted when the channel is changed.

A conventional technique for a bus terminal mounted on a vehicle is disclosed in the following Patent Document 1: Korean Patent Laid-Open Publication No. 10-2007-0033941 (published on Mar. 27, 2007).

Patent Document 1 discloses a system for encrypting and binarizing a file that has collected transaction contents collected from at least one bus terminal that has entered a predetermined communication area and transmitting the encrypted and binarized file to a settlement system and storing a version of information stored in the settlement system, The bus terminal is managed by comparing the versions of the information and updating the information stored in the terminal with the latest information.

Korean Patent Publication No. 10-2007-0033941 (published on Mar. 27, 2007)

However, since the conventional channel change method of the driver terminal changes the channel after searching for the channel in a state where the received signal strength is lower than a certain level, it takes a considerable time until the optimum channel change . The longer the channel change time means that the communication disconnection time becomes longer or the communication error state becomes longer.

In addition, since a general driver terminal is a wireless communication system using a 2.4 GHz band, there is a disadvantage that channel congestion is high, channel bandwidth is narrow, and channel interference is large.

In addition, the conventional bus terminal disclosed in Patent Document 1 has a disadvantage in that it has no function to avoid channel congestion.

SUMMARY OF THE INVENTION An object of the present invention is to solve the above-described problems occurring in general driver terminals and bus terminals of the related art, and it is an object of the present invention to provide a wireless communication system, The present invention provides a channel congestion avoidance apparatus and method for a driver terminal that avoids channel congestion based on a high-speed data transmission.

It is another object of the present invention to provide a channel congestion avoidance apparatus and method for a driver terminal that minimizes a communication disconnection time by minimizing a channel change.

According to an aspect of the present invention, there is provided a channel congestion avoidance apparatus for a mobile communication terminal, the channel congestion avoidance apparatus comprising: a channel searching unit connected to a base station for relaying wireless communication; An access point (AP) for generating and providing a channel list for avoiding the channel list; And a driver terminal for changing a channel based on a channel list provided by the AP when the channel is changed.

The access point includes a channel search unit for searching for a channel by accessing the base station, and extracting a received signal strength for a search channel; A radio environment information obtaining unit for obtaining radio environment information on the search channel; And a channel list generator for generating a channel list for avoiding channel congestion based on the received signal strength of the channel searched by the channel searching unit and the radio environment information obtained by the radio environment information obtaining unit .

The wireless environment information includes service channel information of a neighbor access point for a serviceable channel.

The channel list generation unit generates a channel list based on the order in which the received signal strength is high and the non-serving channel in the peripheral access point as priorities.

The access point includes a channel list database for storing the channel list generated by the channel list generating unit in a database.

The driver terminal may include a channel state determiner for determining a state of a currently occupied channel and generating a channel change command upon changing a channel of the occupied channel; And a channel changing unit for changing a channel by receiving a channel list from the access point according to the channel change command transmitted from the channel state determining unit.

The channel state determination unit detects a received signal strength of a current occupied channel and determines that the channel is changed if the received signal strength is less than or equal to a preset threshold value and is maintained for more than a predetermined time.

The channel change unit changes a channel by receiving a channel list from the access point according to a channel change signal generated when a user manually inputs a channel change command through a channel change operation unit.

In order to achieve the above object, a method for avoiding channel congestion of a driver terminal according to the present invention comprises the steps of: (a) comparing a reception intensity of a specific channel with a predetermined threshold for channel change during communication with a specific channel ; (b) if the reception strength of the specific channel is lower than the threshold value, confirming whether the reception strength is lower than a threshold value for a set time; (c) acquiring a channel list from an access point when the reception strength is lower than the threshold for a preset time; (d) changing the channel according to the priority of the acquired channel list.

According to another aspect of the present invention, there is provided a method for avoiding channel congestion in a driver terminal, comprising the steps of: (e) if the reception strength of the specific channel is higher than the predetermined threshold, Checking whether a channel change is requested, and moving to step (c) for channel change when the channel change is manually requested.

The priority of step (d) may be set according to the order of increasing reception strength and the channel not served by the neighboring access point.

According to the present invention, channel congestion is avoided on the basis of received signal strength (RSSI) and neighboring radio environment information acquired through an access point (AP), thereby enabling high-speed data transmission at all times.

According to the present invention, channel change can be minimized, and communication disconnection time can be minimized.

1 is a configuration diagram of a driver terminal apparatus according to the present invention;
FIG. 2 is a block diagram of an embodiment of the access point of FIG. 1,
FIG. 3 is a block diagram of an embodiment of the driver terminal of FIG. 1,
4 is a flowchart illustrating a channel congestion avoidance method of a driver terminal according to the present invention.

Hereinafter, an apparatus and method for avoiding channel congestion in a driver terminal according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

FIG. 1 is a schematic block diagram of an apparatus for avoiding channel congestion of a driver terminal according to a preferred embodiment of the present invention, and includes an antenna 10, an access point (AP) 20, and a driver terminal 30.

The access point 20 performs channel search by accessing a base station relaying wireless communication, and generates and provides a channel list for avoiding channel congestion based on the channel search result and the acquired radio environment information.

As shown in FIG. 2, the access point 20 includes a communication unit 21 for wireless communication with the base station; A channel search unit (22) for searching for a channel in connection with the base station and extracting a received signal strength for a search channel; A radio environment information obtaining unit (23) for obtaining radio environment information on the search channel; A channel list generating unit 23 for generating a channel list for avoiding channel congestion based on the received signal strength for the channel searched by the channel searching unit 22 and the radio environment information obtained by the radio environment information obtaining unit 23, (24); And a channel list database (DB) 25 for storing the channel list generated by the channel list generating unit 24 in a database.

Herein, the radio environment information includes service channel information of a neighboring access point to a serviceable channel, and the channel list generating unit 24 generates a channel list having priority levels Thereby generating a channel list.

The driver terminal 30 changes a channel based on a channel list provided by the access point (AP) 20 when a channel is changed.

As shown in FIG. 3, the driver terminal 30 includes a communication unit 31 for communicating with the access point 20; A channel state determination unit (33) for determining a state of a currently occupied channel and generating a channel change command upon changing a channel of the occupied channel; And a channel changing unit 34 for changing the channel by receiving a channel list from the access point 20 according to the channel change command transmitted from the channel state determining unit 33.

Here, it is preferable that the channel state determiner 33 detects the received signal strength of the current occupied channel, and determines that the channel change is performed when the received signal strength is equal to or less than a predetermined threshold value and is maintained over the set time.

In the above, the channel change unit 34 receives a channel list from the access point 20 according to a channel change signal generated when the user manually inputs a channel change command through the channel change operation unit 32, .

The operation of the channel congestion avoiding apparatus of the driver terminal according to the preferred embodiment of the present invention will now be described in detail.

First, the driver terminal 30 establishes an initial specific channel through the access point 20, performs wireless communication with a remote management server using the specific channel as an occupied channel, transmits the vehicle driving information, And receives necessary information. And the approval of the card information read from the traffic card presented by the passenger for the fare calculation.

Here, in the present invention, dual-band communication is performed between the access point 20 and the management server using 5 GHz as a main channel and 2.4 GHz as a sub-channel. Here, the radio communication in the 5 GHz band has a channel congestion lower than that of the existing 2.4 GHz band, and has an advantage of ensuring the optimal transmission speed because of the wide channel bandwidth.

The access point 20 periodically or aperiodically performs a channel search in order to avoid channel congestion in the channel search unit 22 when the driver terminal 30 normally performs communication through the occupied channel. In this case, it is desirable to set the channel search so that wireless communication operation is not infeasible, and in the present invention, 15 seconds is set as an embodiment.

The channel list generating unit 24 generates a primary channel list by assigning priorities of channels according to the detected reception intensities, detects the reception intensities (received signal strengths: RSSI) .

For example, a primary channel list is created by sorting in descending order so that the channel with the highest reception strength becomes the highest priority and the channel with the next highest reception strength becomes the next priority.

Next, the radio environment information obtaining unit 20 communicates with other neighboring access points (APs) through the communication unit 21 or acquires radio environment information on the neighboring access points through the base station, And supplies it to the generation unit 24. That is, channel information on which channel is used as a service channel in the neighboring access point, and the like is acquired as radio environment information.

The channel list generator 24 combines the primary channel list and the radio environment information to generate an optimal channel list for avoiding channel congestion and stores the database in the channel list database 25 as a database.

For example, if the highest-priority channel selected in the primary channel list is an idle channel that is not currently served by another access point, it is set as the highest priority channel, and the highest-priority channel selected in the primary channel list is set as the highest- , It is confirmed whether or not the next Chow priority channel is currently used as a service channel in another access point in a state of rank hold. If it is determined that the Churn priority channel is currently being used as a service channel in another access point, the channel is temporarily placed in a reserved position but is placed under the highest priority channel. On the other hand, if the chauvinistic priority channel is an empty channel that is not currently used as a service channel in another access point, the chauvinistic priority channel is once ranked as a top priority channel.

In this way, a channel list for avoiding channel congestion is generated and stored in the channel list database 25.

Here, it is preferable that the selected channels in the primary channel list basically generate the channel list using only the channel having the reception strength of -60 dBm or more. Thereby, no matter what channel the primary channel list is used to change the channel, the driver terminal 30 performs wireless communication at all.

On the other hand, the access point 20 periodically or non-periodically generates a list of channels to be changed in the above-described manner and converts it into a database.

In addition, the driver terminal 30 communicates with the initially occupied channel irrespective of the channel list of the access point 20, and the channel state determiner 33 determines the channel state in real time.

Here, the channel state determination is performed by detecting the signal strength of the occupied channel. For example, when the reception strength is -60 dBm or less, since the reception strength is low, it is determined that the channel is changed first. Then, it is confirmed whether the state of -60 dBm or below is maintained for more than a predetermined set time (for example, two minutes). In the present invention, the channel change is not performed immediately even in the case where the reception strength is weak, because communication disruption occurs when the channel is changed. In this case, even if the passenger boarded and tagged the traffic card at the predetermined position, the traffic card information of the actual passenger can not be read and processed. Therefore, in order to minimize the communication disruption time, the channel change is not performed even if the reception strength becomes weak. Also, since the bus is a moving object, it is affected by changes in the surrounding environment. Therefore, the reception strength can be temporarily weakened by the surrounding environment, and the original reception strength can be recovered again after the transient time. In this case, if the channel change is performed, Adverse effects may occur. Therefore, the present invention minimizes the communication disconnection time and does not perform the instantaneous channel change in order to maximize the function of automatically escaping from the channel confusion.

If the state of -60 dBm or less is not maintained for a predetermined set time or longer and the original reception strength is recovered again, it is determined that the channel change is not performed. Otherwise, the state of -60 dBm or less is longer than the set time It is determined that the channel is changed and the channel change command is transmitted to the channel changing unit 34. [

When the channel change command is received, the channel change unit 34 requests the access point 20 for a channel list. The access point 20 transmits the channel list for the changed channel previously registered in the channel list database 25 to the channel changing unit 34 in response to the request. The channel changing unit 34 extracts channel information corresponding to a highest priority position located at the uppermost position in the received channel list, and quickly changes the channel based on the extracted channel information. Here, since the channel corresponding to the highest priority is an idle channel not used by other peripheral access points, channel congestion can be prevented.

Therefore, the present invention reduces the channel change time compared to the conventional method, thereby minimizing the communication disconnection time when changing the channel. In other words, in the past, a process of searching for a channel when changing a channel and changing to a searched channel has been performed. However, according to the present invention, an optimal change channel is prepared in advance and changed to a channel prepared at the time of channel change. So that it can be minimized.

The channel change method is a method of automatically changing a channel by detecting a reception intensity and a radio environment change, and the present invention can manually change a channel.

For example, when the user manually inputs a channel change command through the channel change operation unit 32, the channel change unit 34 changes the channel in the same manner as described above. This allows manual channel switching.

4 is a flowchart illustrating a method for avoiding channel congestion in a driver terminal according to the present invention, wherein S represents a step.

As shown in FIG. 4, the method for avoiding channel congestion of a driver terminal according to the present invention includes the steps of: (a) comparing the reception strength of the specific channel with a preset threshold value for channel change during communication with a specific channel S101 to S102); (b) if the reception strength of the specific channel is lower than the threshold value, confirming whether the reception strength is lower than a threshold for a predetermined time (S104); (c) acquiring a channel list from the access point when the reception strength is lower than the threshold for a preset time (S105); (d) changing a channel according to the priority of the acquired channel list (S 106); (e) if the reception strength of the specific channel is higher than the predetermined threshold as a result of the comparison in the step (a), it is checked whether a channel change is requested manually, and when the channel change is manually requested, And moving to step (c) (step S103).

It is preferable that the priority of step (d) is set according to the order in which the reception strength is large and the channel that is not served by the peripheral access point.

In the method of avoiding channel congestion in the driver terminal according to the present invention configured as described above, the receiving strength of the specific channel is changed in real time or periodically in the course of wireless communication with the management server in the specific channel in step S101, (E. G., -60 dBm). ≪ / RTI >

If the reception strength of the specific channel is greater than the threshold value, the process proceeds to step S103, where it is checked whether the user manually requested the channel change.

On the other hand, if the reception strength of the specific channel is smaller than the threshold value, the process proceeds to step S104 to check whether the reception strength is lower than the threshold value for a predetermined time (for example, two minutes). Here, one example of the set time is 2 minutes, which is set by averaging the arrival and departure times of the bus stop.

If it is determined that the reception strength is lower than the threshold value for the preset time, it is determined that the channel is not changed, and the process proceeds to the first step S101. On the other hand, if the reception strength is lower than the threshold value for a preset time, it is determined that the channel is changed, and the flow advances to step S105 to acquire the channel list from the access point.

In step S106, the channel is changed according to the priority of the acquired channel list.

If it is determined in step S103 that the user has not requested the channel change, the process proceeds to step S101. If the user manually requests the channel change, the process proceeds to step S105 to obtain the channel list from the access point . In step S106, the channel is changed according to the priority of the acquired channel list.

The present invention described above minimizes the channel disconnection time by minimizing the channel change by not changing the channel in case of a temporary change of the surrounding environment. In addition, it is possible to minimize the channel change time by preparing the optimum change channel in advance and changing it to the channel prepared at the time of channel change.

Although the present invention has been described in detail with reference to the above embodiments, it is needless to say that the present invention is not limited to the above-described embodiments, and various modifications may be made without departing from the spirit of the present invention.

The present invention is applied to a driver terminal mounted on a bus. In particular, it is effectively applied to a technique of changing a channel in a driver terminal.

10; antenna
20; The access point (AP)
22; Channel search section
23; Wireless environment information acquisition unit
24; The channel list generating unit
30; Driver's terminal
32; The channel-
33; The channel-
34; The channel-

Claims (11)

An access point (AP) connected to a base station for relaying wireless communication to perform channel search, and generating and providing a channel list for avoiding channel congestion based on the channel search result and the acquired wireless environment information;
And a driver terminal for changing a channel based on a channel list provided by the AP when a channel is changed,
Wherein the access point includes a channel list generator for generating a channel list for avoiding channel congestion based on the received signal strength, which is the channel search result, and the radio environment information,
Wherein the radio environment information includes service channel information of a neighboring access point to a serviceable channel,
Wherein the channel list generation unit generates a channel list in a descending order of the received signal strength and a non-serving channel in a peripheral access point as priorities.
The apparatus of claim 1, wherein the access point comprises: a channel search unit for searching for a channel by accessing the base station and extracting a received signal strength for a search channel; And a radio environment information obtaining unit for obtaining radio environment information on the search channel.
delete delete The apparatus of claim 1, wherein the access point comprises a channel list database for storing the channel list generated by the channel list generating unit in a database.
The method of claim 1, wherein the driver terminal comprises: a channel state determiner for determining a state of a currently occupied channel and generating a channel change command upon changing a channel of the occupied channel; And a channel changing unit for changing a channel by receiving a channel list from the access point according to the channel change command transmitted from the channel state determining unit.
7. The method of claim 6, wherein the channel state determination unit detects a received signal strength of a currently occupied channel, and determines that the channel change is performed when the received signal strength is equal to or less than a preset threshold value and is maintained over a set time period. Channel congestion avoidance device.
The system of claim 6, wherein the channel change unit receives a channel list from the access point according to a channel change signal generated when a user manually inputs a channel change command through a channel change operation unit, A device for avoiding channel congestion in a terminal.
(a) comparing the reception strength of the specific channel with a predetermined threshold for channel change during communication with a specific channel;
(b) if the reception strength of the specific channel is lower than the threshold value, confirming whether the reception strength is lower than a threshold value for a set time;
(c) acquiring a channel list from an access point when the reception strength is lower than the threshold for a preset time;
(d) changing a channel according to a priority of the acquired channel list;
(e) if the reception strength of the specific channel is higher than the predetermined threshold as a result of the comparison in the step (a), it is checked whether a channel change is requested manually, and when the channel change is manually requested, And moving to step (c)
Wherein the priority of the step (d) is set in a priority order based on a channel having a higher reception strength and a channel not served by a neighboring access point.

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