KR20110128147A - Ap, terminal and method for processing ap acess control based on congestion level of transmission chennel - Google Patents

Abstract

PURPOSE: An AP, a terminal and a method thereof performing an AP access control and considering the complexity of transmission channel are provided to select an AP by enabling a user to utilize the complexity information of the transmission channel expressing that the traffic load level of an AP and the signal strength information which is received from an AP. CONSTITUTION: A measuring unit(101) measures the complexity of a transmission channel expressing the collision complexity between frame in a busy channel interval. A broadcasting unit(103) broadcasts the complexity of the transmission channel to a terminal which is included in the service range of the AP by including the complexity of the transmission channel to the beacon frame. The measuring unit measures an agreement rate of an idle time and the busy time as the complexity of the transmission channel.

Description

Ap, terminal and method for performing ap connection control in consideration of congestion of a transmission channel {AP, TERMINAL AND METHOD FOR PROCESSING AP ACESS CONTROL BASED ON CONGESTION LEVEL OF TRANSMISSION CHENNEL}

The present invention relates to an AP, a terminal, and a method for performing AP access control in consideration of congestion of a transport channel.

Currently, a general-purpose wireless LAN terminal, for example, a notebook equipped with a wireless LAN function, a portable terminal having a wireless LAN function, that is, a smart phone, selects an access point (AP) to access to use a wireless LAN service.

At this time, the AP to be connected is selected depending on the strength information of the signal received from the AP. Therefore, it does not consider how many terminals are connected within the basic service set (BSS) range serviced by the AP. In addition, the AP is selected without information about the traffic load of the AP by the traffic generated from the connected UE.

If the wireless output signal strength of the AP is high and the traffic load is high, when the terminal selects the AP based only on the wireless signal strength, there is a situation in which the terminal cannot receive a smooth service to be received by the traffic load imposed on the AP. Occurs.

As described above, when the terminal desires to access the AP, if the AP determines whether to access the AP simply by relying on the strength of the signal transmitted from the AP, the additional terminal is connected to the AP despite the congestion of the channel condition of the AP. It can worsen.

In addition, conventionally, a method using a method of first selecting an AP to be connected by the signal strength from the AP and then selecting the AP again according to the number of terminals connected to the AP has been proposed.

However, the problem with this method is that it does not check whether the connected terminal is currently in service. In addition, since the type of traffic generated, for example, does not determine whether the traffic is voice, simple web surfing, video streaming, etc., the amount of traffic charged to the AP cannot be predicted.

However, the traffic load imposed on the AP may appear in various forms depending on what service the access terminal performs.

For example, if the AP operates at 11 Mbps in 802.11b mode, the number of terminals that can be connected for voice calls (VoWLAN, Voice over WLAN) is guaranteed, that is, the voice quality is less than 10, but simply for web surfing If it is, the number goes well beyond teens.

Therefore, simply distributing only a certain number of terminals connected to one AP does not properly distribute the traffic to the AP.

An object of the present invention is to provide an AP, a terminal, and a method for performing AP access control to select an AP by using not only signal strength information received from the AP, but also congestion information of a transport channel indicating a traffic load of the AP. To provide.

According to one aspect of the invention, an AP is provided. The AP may include a measuring unit for measuring a congestion degree of a transmission channel indicating a collision probability between frames in a channel busy period in an access point (AP); And a broadcasting unit including the congestion degree of the transmission channel in a beacon frame and broadcasting to a terminal within a service range of the AP.

According to another feature of the invention, an AP is provided. The AP may include a measuring unit measuring a congestion degree of a transmission channel indicating a collision probability between frames in a channel busy period; And a transmission unit including the congestion degree of the transmission channel in a response frame to the AP search request frame received from the terminal and transmitting the congestion degree to the terminal.

According to another feature of the invention, a terminal is provided. The terminal includes a scan unit for receiving each frame from one or more APs through a scanning process; An extraction unit for extracting a congestion degree of a transmission channel measured by the one or more APs included in each frame, wherein the congestion degree of the transmission channel indicates a collision probability between frames in a channel busy period; And a selector for selecting an AP to access from the one or more APs based on the congestion degree of the transmission channel.

According to another feature of the present invention, an access control method of an AP is provided. The method includes a method of controlling an access point (AP), the method comprising: measuring, by the AP, a congestion degree of a transmission channel indicating a collision probability between frames in a channel busy period; And transmitting the congestion degree of the transmission channel to the terminal.

According to another feature of the present invention, an AP access control method of a terminal is provided. The method includes: receiving each frame from one or more APs through a scan process for searching for an access point (AP) to which the terminal is to access; Extracting a congestion degree of a transmission channel measured by the at least one AP from each frame, wherein the congestion degree of the transmission channel indicates an inter-frame collision probability in a channel busy period; And selecting an AP to access from the one or more APs based on the congestion degree of the transport channel.

According to an embodiment of the present invention, the congestion status of the AP can be monitored to access the AP in advance of a high-load AP, thereby improving the distribution effect of the traffic imposed on the AP and the overall quality of service experienced by the terminal. have.

1 is a configuration diagram of a wireless network according to an embodiment of the present invention.
2 is a view for explaining a case of transmitting a frame between the AP and the terminal according to an embodiment of the present invention.
3 shows a frame structure according to an embodiment of the present invention.
4 is a block diagram illustrating an internal configuration of an AP according to an embodiment of the present invention.
5 is a flowchart illustrating a process in which an AP provides information for controlling an AP access of a terminal according to an embodiment of the present invention.
6 is a flowchart illustrating a process in which an AP provides information for controlling an AP access of a terminal according to another embodiment of the present invention.
7 is a block diagram showing the internal configuration of a terminal according to an embodiment of the present invention.
8 is a flowchart illustrating an AP access control method according to an embodiment of the present invention.
9 is a screen example of a terminal according to an embodiment of the present invention.

DETAILED DESCRIPTION Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art may easily implement the present invention. The present invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, parts irrelevant to the description are omitted in order to clearly describe the present invention, and like reference numerals designate like parts throughout the specification.

Throughout the specification and claims, when a portion is said to "include" a certain component, it means that it can further include other components, without excluding the other components, unless specifically stated otherwise.

Throughout the specification, a terminal may include a user equipment (UE), a mobile terminal (MT), a mobile station (MS), a subscriber station (SS), and a portable subscriber station (PSS). ) May be referred to as an access terminal (AT), and may include all or part of the functions of the terminal, MT, MS, SS, PSS, AT, and the like.

In addition, an access point (AP) may be a base station (BS), a node B (node B), an advanced node B (evolved node B, eNodeB), a radio access station (radio access station, RAS), a base transceiver station may refer to a base transceiver station (BTS), a mobile multihop relay (MMR) -BS, or the like, and may include all or a part of functions of a NodeB, an eNodeB, an AP, a RAS, a BTS, an MMR-BS, and the like.

Now, an AP, a terminal, and a method for performing AP access control in consideration of congestion of a transmission channel according to an embodiment of the present invention will be described with reference to the drawings.

1 is a configuration diagram of a wireless network according to an embodiment of the present invention.

Referring to FIG. 1, a plurality of APs (Access Points) 100 exist, and the terminal 200 selects and connects one AP from among a plurality of APs (AP1, AP2, and AP3).

The plurality of APs AP1, AP2, and AP3 100 are connected to a wireless LAN (WLAN) switch 301 of the wireless access network 300, and the wireless access network 300 is connected to the IP backbone network 400. do.

Here, the plurality of APs (AP1, AP2, AP3) 100 monitors (1) the transmission channels BSS1, BSS2, and BSS3 of each BSS (Basic Service Set). The congestion level of the channel is measured to broadcast congestion level indication to the terminal 200 located within a service range of each AP (AP1, AP2, AP3) (2). Then, the terminal 200 selects a specific AP to access based on the received congestion information (③).

Hereinafter, the measurement of the degree of congestion and the degree of congestion will be described in more detail with reference to FIGS. 2 and 3.

2 is a view for explaining a case of transmitting a frame between the AP and the terminal according to an embodiment of the present invention.

Referring to FIG. 2, according to the IEEE 802.11 WLAN standard, a transmission channel of a BSS composed of an AP 100 and a terminal 200 has a transmission section TX, a reception section RX, and a pause according to whether a transmission frame exists. It is divided into IDLE.

When the transmission channel is divided into a predetermined time interval (Tch) and expressed as t0, t1, t2, ..., the transmission between the AP 100 and the terminal (WSTA) 200 during the Tch time between t0 and t1. The channel state occupied by the frame is interpreted as follows from the AP perspective.

First, the AP 100 transmits a frame TX to WSTA to the terminal 200 and waits for an ACK response thereto. The above corresponds to the frame transmission process from the AP perspective.

After that, while the channel experiences IDLE because there is no frame transmission, the AP 100 receives the frame TX to AP from the terminal 200 and transmits an ACK to the terminal 200 in response. do. The above corresponds to the frame reception process from the AP perspective.

In this case, the frame receiving process from the AP perspective may determine that the channel is occupied by another terminal 200, and this section may be represented as a channel busy section. If the AP 100 or another terminal 200 transmits a frame in the channel busy period, a collision occurs and a transmission error occurs in the corresponding frame.

Therefore, the congestion degree of the channel can be measured by the busy time and the IDLE time of the channel measured for a specific time.

In this case, the channel congestion may be expressed as a frame collision probability. The collision collision probability measured at a specific time is defined as in Equation 1 below.

The frame collision probability calculated through Equation 1 represents the congestion degree of the transmission channel and is broadcast to the terminal 200 connected to the AP 100 through a beacon frame. In addition, when the terminal 200 wishing to access the AP 100 requests a Probe Request to search for an AP, a congestion rate of a transmission channel is provided to the terminal 200 through a Probe Response frame.

At this time, the beacon frame and the probe response frame including the congestion of the transmission channel is configured as shown in FIG.

3 shows a frame structure according to an embodiment of the present invention.

Referring to FIG. 3, a beacon frame and a probe response frame (hereinafter, collectively referred to as a 'frame') include a MAC header field, a frame body field, and a frame check sequence (FCS) field.

Here, the frame body field defines an additional information element for indicating congestion information in addition to the previously defined information element.

The added information element uses order = 25, which is not defined in the standard based on the IEEE 802.11-2007 standard, and the information name is defined as Collision Probability.

The order and Information names can be modified to suit your situation. The information element (Collision Probability) is composed of an element ID field and a length field. The element ID is set to 52 and the length field is assigned 2 octets to express collision probability.

The collision probability inserted in the Length field is entered as an integer, and the unit is expressed as 10e-6. Here, the expression method of element ID and collision probability can be modified according to the situation.

Now, a configuration of an AP and a terminal performing AP access control in consideration of the congestion degree of the transmission channel described above, and a series of processes of AP access control will be described. At this time, only the configuration related to the AP access control considering the congestion of the transmission channel is shown.

4 is a block diagram illustrating an internal configuration of an AP according to an embodiment of the present invention, FIG. 5 is a flowchart illustrating an AP access control process according to an embodiment of the present invention, and FIG. 6 is a diagram illustrating another embodiment of the present invention. A flowchart illustrating an AP access control process according to the present invention.

Referring to FIG. 4, the AP 100 includes a measuring unit 101, a broadcasting unit 103, a receiving unit 105, and a transmitting unit 107.

At this time, the AP access control operation of the AP 100 may include two embodiments, and the operations of the two embodiments may be performed simultaneously or in parallel. The operation of the two embodiments is described as follows.

First, an embodiment will be described with reference to FIG. 5.

The measuring unit 101 measures congestion of the transmission channel (S101). At this time, as described in FIG. 2, the congestion rate of the transmission channel is divided into transmission (TX), reception (RX), and idle (Idle) sections according to a packet transmission state according to a packet transmission state. The measurement is performed at the rate occupied by the reception section RX in the remaining time sections except for (TX).

Then, the broadcasting unit 103 broadcasts the congestion degree of the transmission channel measured in step S101 to the beacon frame to the terminal 200 located within the service range of the AP 100 (S103).

Next, another embodiment will be described with reference to FIG. 6.

Referring to FIG. 6, the measurement unit 101 measures congestion of the transmission channel as in FIG. 5 (S201).

Thereafter, the receiver 105 receives a probe request frame for searching for an AP from the terminal 200 (S203).

Then, the transmission unit 107 receives the congestion degree of the transmission channel measured in step S201 from the measurement unit 101 is recorded (S205) in the probe response (Probe Response) frame and transmitted to the terminal 200 (S207).

7 is a block diagram illustrating an internal configuration of a terminal according to an embodiment of the present invention, FIG. 8 is a flowchart illustrating a method for controlling access to an AP according to an embodiment of the present invention, and FIG. 9 is an embodiment of the present invention. Example of the screen of the terminal according.

Referring to FIG. 7, the terminal 200 includes a scan unit 201, an extraction unit 203, a storage unit 205, a selection unit 207, and a display unit 209. 8 illustrates an AP access process of the terminal 200.

When the terminal 200 wants to access the wireless AP 100, the scan unit 201 searches for a neighboring AP to which the terminal 200 can access through the scanning process S301.

Here, the scanning process is performed for all channels that can be accessed through the wireless LAN interface (not shown) of the terminal 200.

In this case, the scan unit 201 receives a frame from one or more APs 100 (S303).

Here, the frame may be a beacon frame broadcast by the AP 100. Alternatively, the probe may be a probe response frame received in response to a probe request frame transmitted by the scan unit 201. Here, the probe request frame is an AP search request frame that the terminal 200 actively transmits to the AP 100.

Then, the extractor 203 extracts congestion information (collision probability) of the transmission channel from the beacon frame or the probe response frame received in step S303 (S305).

Here, the extractor 203 determines the type of the received frame from the frame control field and determines who the transmission subject is based on the SA and BSS ID field information. When the received frame is transmitted from the AP 100 and the type of the received frame is determined to be a beacon frame or a probe response frame, the frame body of the received frame is interpreted (or decoded).

Referring to FIG. 3, for example, it is checked whether the 'element ID' is 52, and as many octets (eg, 2 octets) recorded in the next length field are recognized and extracted as a collision probability.

In this case, since the unit of congestion is represented by 10e-6, if the result of decoding the congestion field is 3546, the value of the actual congestion becomes 0.003456.

In this manner, the collision probability value, that is, the congestion degree, is extracted from the frame received from the AP 100 and stored in the storage unit 205 over all channels.

In addition, the extraction unit 203 displays the congestion degree stored in the storage unit 205 on the screen of the terminal 200 as shown in FIG. 9 through the display unit 209 for each AP (AP1, AP2, AP3) (S307). .

In addition, the extraction unit 203 checks the signal strength information and the transmission rate information currently accessible from the frame received in step S303 (S309).

Then, the selector 207 selects the AP 100 to be connected based on the congestion degree extracted in step S305, the signal strength information checked in step S307, and the transmission rate information that can be accessed at step S311.

For example, based on the frames received from AP1, AP2, and AP3 in FIG. 1, assuming that signal strength and transmission rate are the same, the selector 207 measures the congestion measured and transmitted by each of AP1, AP2, and AP3. Compare.

At this time, if the degree of congestion has a large value in order of AP1 <AP2 <AP3, the selector 207 selects AP1 having the lowest degree of congestion. In this way, the quality of the service generated in the terminal 200 can be guaranteed.

Although the embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements of those skilled in the art using the basic concepts of the present invention defined in the following claims are also provided. It belongs to the scope of rights.

Claims (15)

In the AP (Access Point),
A measurement unit measuring a congestion degree of a transmission channel indicating a collision probability between frames in a channel busy period; And
Broadcasting unit for including the congestion of the transmission channel in the beacon frame to broadcast to a terminal within the service range of the AP
AP comprising a. In the AP (Access Point),
A measurement unit measuring a congestion degree of a transmission channel indicating a collision probability between frames in a channel busy period; And
Transmitter including the congestion of the transmission channel in the response frame to the AP search request frame received from the terminal to transmit to the terminal
AP comprising a. The method according to claim 1 or 2,
The measuring unit,
An AP for measuring the busy time of the transmission channel measured for a predetermined time, and the ratio of the sum of the busy time and IDLE time as the congestion of the transmission channel. A scan unit which receives each frame from at least one access point (AP) through a scanning process;
An extraction unit for extracting a congestion degree of a transmission channel measured by the one or more APs included in each frame, wherein the congestion degree of the transmission channel indicates a collision probability between frames in a channel busy period; And
A selector for selecting an AP to access from the one or more APs based on the congestion degree of the transmission channel
. The method of claim 4, wherein
The extraction unit,
Confirm signal strength and transmission rate of each of the one or more APs;
The selection unit,
And selecting the AP with the lowest congestion as an AP to access when the signal strengths and transmission rates are the same. The method of claim 4, wherein
A display unit for outputting a congestion degree of each of the one or more APs extracted by the extractor to a screen
Terminal further comprising. The method of claim 4, wherein
The scan unit,
Receiving a beacon frame broadcasted by each of the one or more APs or a response frame for each AP search request sent to the one or more APs,
The beacon frame or the response frame includes the congestion degree. The method of claim 7, wherein
The extraction unit,
And extracting the congestion degree from a newly defined information element among the frame body field of the beacon frame or the response frame. In the access control method of the access point (AP),
Measuring, by the AP, a congestion degree of a transmission channel indicating a collision probability between frames in a channel busy period; And
Transmitting congestion of the transmission channel to a terminal
Access control method of the AP comprising a. 10. The method of claim 9,
The transmitting step,
Including the congestion of the transmission channel in a beacon frame to broadcast to a terminal within a service range of the AP; And
Including the congestion degree of the transmission channel in a response frame to the AP search request frame received from the terminal and transmitting the same to the terminal;
Method of controlling the access of the AP comprising at least one of. The method of claim 9 or 10,
The measuring step,
An access control method of an AP that measures the ratio of a reception section in a remaining time section except for a transmission section in a predetermined specific time section of a transmission channel as the congestion of the transmission channel. In the access point (AP) access control method of the terminal,
Receiving each frame from at least one AP through a scan process for searching for an access point (AP) to which the terminal is to access;
Extracting a congestion degree of a transmission channel measured by the at least one AP from each frame, wherein the congestion degree of the transmission channel indicates an inter-frame collision probability in a channel busy period; And
Selecting an AP to access from the one or more APs based on the congestion degree of the transport channel
AP access control method of a terminal comprising a. The method of claim 12,
The extracting step,
Extracting congestion of the transmission channel from each frame; And
Identifying signal strength and transmission rate of each of the one or more APs through the respective frames;
The selecting step,
The AP access control method of the terminal to select the AP with the lowest congestion as the AP to access when the signal strength and transmission rate are the same. The method of claim 13,
The extracting step,
Before extracting the congestion degree of the transmission channel, determining whether a transmission subject of a frame received from the at least one AP is an AP; And
If it is determined that the transmitting entity is the AP, determining whether the received frame is a beacon frame or a response frame to the AP search request by checking the type of the received frame;
Extracting the congestion of the transport channel,
If the type of the received frame is a beacon frame or a response frame to the AP search request, extracting the congestion degree. The method of claim 14,
Extracting the congestion of the transport channel,
Interpreting a frame body field of the beacon frame or the response frame;
Determining whether an element ID of a newly defined information element in the frame body field is a predefined value; And
Recognizing and extracting the octet value recorded in the length field of the information element when the element ID is a predefined value
AP access control method of a terminal comprising a.

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