KR100790389B1 - The interference eliminating method of the piconet using the channel time allocation which is an intelligent - Google Patents

Abstract

The present invention relates to a method for canceling piconet interference using intelligent channel time allocation, wherein the PNC-1 adjusts a superframe to simultaneously operate the piconet-1 and piconet-2 having a common area, and the PNC-1 and A first step of the PNC-2 transmitting a beacon signal including superframe adjustment information of a common region to all DEVs; The DEV receiving the beacon signal from the PNC-1 or the PNC-2 determines whether it is included in the common area, and the P-DEV included in the common area includes a second step of requesting a channel time from the P-CTA; And a third process of allocating the channel time according to the channel time request by the PNC-1 and PNC-2; It includes.

According to the present invention as described above, by using the intelligent channel time allocation (Intelligent CTA) including the open channel time allocation (P-CTA) and the normal channel time allocation (N-CTA), it occurs in the common area between the piconets This can eliminate interference and increase the throughput of piconets.

Piconet, Superframe, and MAC (Media Access Control)

Description

The interference eliminating method of the piconet using the channel time allocation which is an intelligent}

1 is a diagram illustrating a structure of an IEEE 802.15.3 superframe according to an embodiment of the present invention.

2 is a diagram illustrating a structure of a parent superframe having a child and a neighbor superframe according to an embodiment of the present invention.

3 illustrates a structure of a superframe having aligned beacons B1 and B2 according to an embodiment of the present invention.

4 is a view showing a state in which piconet-1 and piconet-2 overlap in accordance with one embodiment of the present invention;

5 is a flowchart illustrating a method of canceling interference of a piconet using intelligent channel time allocation according to an embodiment of the present invention.

6 is a detailed flowchart of a first process according to an embodiment of the present invention.

7 illustrates a structure of a coordinated superframe for supporting two SOPs according to an embodiment of the present invention.

8 is a detailed flowchart of a second process according to an embodiment of the present invention;

9 illustrates a control format of CTRq for supporting P-CTAs according to an embodiment of the present invention.

The present invention relates to an interference cancellation method of a piconet, and more particularly, by applying an intelligent channel time allocation method based on the IEEE 802.15.3 MAC protocol, interference between piconets having a common area can be eliminated. It is about how.

Ultra wideband (UWB), a next-generation wireless communication technology, is a wireless technology for transmitting a large amount of digital data through a wide spectrum frequency at low power. In other words, a working group for establishing a wireless PAN standard is in progress. IEEE 802.15.3. IEEE 802.15.3, a high-rate WPAN technology developed by the Working Group, refers to a communication protocol that supports high-speed multimedia transmission between wireless devices at close range.

The IEEE 802.15.3 MAC protocol is designed to support high-rate wireless personal area networks (WPANs) at low power, and is an ad hoc network called a piconet around a piconet mediator (PNC). It operates on the principle of Time Division Multiple Access (TDMA) within one piconet for interference-free connection between devices (hereinafter, referred to as 'DEV').

FIG. 1 is a block diagram illustrating a superframe of IEEE 802.15.3. As illustrated, the m-th superframe includes a beacon, a content access period (hereinafter, referred to as a 'CAP'), and a channel. Channel Time Allocation Period (hereinafter, referred to as 'CTAP').

At the beginning of every superframe, the PNC sends a beacon that provides piconet timing information, and the CAP controls how data is accessed simultaneously and asynchronously.

CTAP consists of Channel Time Allocation (CTA) and Management CTA (MCTA), and CTA is used to connect simultaneous or asynchronous data communication according to the access method controlled by CAP. Used for communication between PNCs.

When src DEV (source DEV) communicates with dest DEV (destination DEV), the src DEV that wants to communicate sends a Channel Time Request ('CTRq') to the PNC. Here, the PNC allocates new CTAs for connection with the dest DEV, and all CTA information including the start time and period are loaded into the beacon and transmitted to the PNC. This is called the 'beacon signal' and according to the transmitted beacon signal, all connections operate during their CTA without any interference.

On the other hand, if different piconets are separated by a considerable distance from one or more piconets at the same time, Inter Piconet Interference (hereinafter, referred to as 'IPI') does not occur. Occurs.

In general, in order to solve such a problem, a method of configuring a piconet in a parent / child or parent / neighbor method and a method of distinguishing beacons have been used.

First, referring to FIG. 2, a method of configuring a piconet as a parent / child or a parent / neighbor, when the PNC detects the presence of another piconet, the PNC is found By forming a parent / naver or parent / naver relationship with a parent, the parent piconet may have one or more dependent piconets, ie, child or neighbor piconet. At this time, the child piconet and NAVER piconet are present in the CTA of the parent piconet.

As shown in FIG. 2, a parent superframe has a child superframe and a neighbor superframe, such as a parent superframe, in a divided Private-CTA. The parent piconet's PNC assigns CTA-1 to Private-CTA, the CTA-3 to private-CTA, and the child piconet and Naver piconet's PNC assign CTAs for links within the piconet. However, the above-described method has a problem in that the throughput of the piconet is not increased because the DEVs of the parent piconet cannot communicate while the child superframe and the neighbor superframe operate.

Meanwhile, referring to FIG. 3, a method of dividing beacons is described. As shown in FIG. 3, all DEVs can accurately receive beacon signals by easily distinguishing the beacons B1 and B2 so as not to operate simultaneously. Although it may be synchronized, there is a problem that interference during CTAP is not eliminated.

The present invention has been made to solve the above problems, by using an intelligent channel time allocation (Intelligent CTA) including public channel time allocation (P-CTA) and general channel time allocation (N-CTA) The purpose of the present invention is to provide an interference cancellation method of piconets using intelligent channel time allocation, which can remove interference from common areas between piconets and increase throughput of piconets.

The present invention relates to a method for canceling piconet interference using intelligent channel time allocation, wherein the PNC-1 adjusts a superframe to simultaneously operate the piconet-1 and piconet-2 having a common area, and the PNC-1 and A first step of the PNC-2 transmitting a beacon signal including superframe adjustment information of a common region to all DEVs; The DEV receiving the beacon signal from the PNC-1 or the PNC-2 determines whether it is included in the common area, and the P-DEV included in the common area includes a second step of requesting a channel time from the P-CTA; And a third process of allocating the channel time according to the channel time request by the PNC-1 and PNC-2; It includes.

Preferably, the first process includes: receiving a beacon signal from a PNC-1 by a DEV present in a common region of piconet-1 and piconet-2; Determining whether the DEV present in the common area receives the beacon signal from the PNC-2 (S130); As a result of the determination in step S130, when receiving, the DEV existing in the common area is operated as an intermediate DEV; Adjusting a superframe to allow Piconet-1 and Piconet-2 with PNC-1 to have a common area at the same time; Transmitting, by the PNC-1, the superframe adjustment information to the PNC-2 through an intermediary DEV; And transmitting, by PNC-1 and PNC-2, a beacon signal including superframe adjustment information of a common area to all DEVs. Characterized in that it comprises a.

Also, as a result of determining in step S130, when the DEV present in the common area does not receive the beacon signal from the PNC-2, the DEV receives the beacon signal including the information on the superframe adjusted from the PNC-1. Doing; It characterized in that it further comprises.

Preferably, the superframe adjustment information may include information divided into beacons B1 and B2 operating at different times, information classified into P-CTAs and N-CTAs, and P-CTAs into P-CTAs. At least one of the information divided into CTA1 and P-CTA2.

Also preferably, the second process may include determining whether the DEV receiving the beacon signal transmitted from the PNC-1 or PNC-2 is included in the common area based on the beacon signal (S210); As a result of the determination in step S210, if included in the common area, transmitting the signal that the P-DEV is included in the common area to the PNC to which it belongs; And after the P-DEV selects any one of the P-CTAs among the P-CTA1 and the P-CTA2, requesting a channel time from the selected P-CTA (S230). Characterized in that it comprises a.

Also, preferably, when it is determined in step S210 that the N-DEV is not included in the common area, transmitting the channel state request signal of the link existing in the common area to the PNC to which it belongs; Transmitting, by the PNC, a response signal to a request signal to the N-DEV; Determining, by the N-DEV, whether interference occurs in the channel based on the response signal received from the PNC (S260); As a result of the determination in step S260, the N-DEV determines that interference does not occur when the channel state of the link is good, and requests channel time from the N-CTA, and determines that interference occurs when the channel state is not good. Selecting a P-CTA from among CTA1 and P-CTA2 and requesting a channel time; It characterized in that it further comprises.

More preferably, before the step S230, the P-DEV is set to Public in the CTRq control frame; It characterized in that it further comprises.

The features and advantages of the present invention will become more apparent from the following detailed description based on the accompanying drawings. Prior to this, the terms or words used in the present specification and claims are defined in the technical spirit of the present invention on the basis of the principle that the inventor can appropriately define the concept of the term in order to explain his invention in the best way. It should be interpreted to mean meanings and concepts. In addition, when it is determined that the detailed description of the known function and its configuration related to the present invention may unnecessarily obscure the subject matter of the present invention, it should be noted that the detailed description is omitted.

Hereinafter, an interference cancellation method of a piconet using intelligent channel time allocation according to the present invention will be described in detail with reference to the accompanying drawings.

Prior to this, interference between Piconet-1 and Piconet-2 having a common area will be described with reference to FIG. As shown, DEV-A belonging to Piconet-1, when receiving a beacon signal from PNC-2, performs an operation to exchange a beacon signal including the start time and period of Simultaneously Operating Piconet (SOP) as an intermediary DEV. Process.

If DEV-1 present in Piconet-1 transmits a signal to DEV-A via an active link (L1), interference occurs when DEV-1 or DEV-A receives a signal from PNC-2. . In addition, when DEV-1 receives a signal from another DEV of piconet-1 through link L2, if DEV-2 transmits a signal to DEV of piconet-2 through link L3, interference occurs accordingly. do. If the Public-DEV existing in the common area wants to transmit and receive the signal correctly, the existing links L2 and L3 are not allowed to operate.

Next, the overall flow of the interference cancellation method of the piconet using intelligent channel time allocation for solving the above-described problem will be described with reference to FIGS.

In the method of eliminating interference of piconets using intelligent channel time allocation according to an embodiment of the present invention, as shown in FIG. 5, the PNC-1 is used to simultaneously operate Piconet-1 and Piconet-2 having a common area as a whole. The first process (S100) of adjusting the superframe, and the PNC-1 and PNC-2 transmits the beacon signal including the superframe adjustment information of the common area to all the DEV, and each DEV receives the received beacon signal On the basis of determining whether it is a common area, the second process (S200) in which the P-DEV requests channel time to the P-CTA or the N-CTA, and the PNC-1 and PNC-2 to the P-CTA and N A third step (S300) of accepting the channel request requested by the CTA and allocating channel times for the DEVs.

First, the first process S100 will be described with reference to FIG. 6, where a common region of piconet-1 and piconet-2 exists (S110), and a DEV present in the common region of piconet-1 and piconet-2 exists. Receive a beacon signal from the PNC-1 (S120).

In this case, as shown in FIG. 4, when the DEV existing in the common area receives a beacon signal from the PNC-2 (S130), the DEV operates as an intermediary DEV (DEV-A), thereby intermediary operation for the common area. To execute (S140). Here, the intermediary DEV handles the operation of exchanging beacon signals including the start time and period of the Simultaneously Operating Piconet (SOP).

The superframe is adjusted (S150) so that the PNC-1 and Piconet-2 having the common area operate simultaneously. Specifically, as shown in FIG. 7, PNC-1 configures a superframe including CAPs, MCTAs, CTAs, and beacons B1 and B2 operating at different times to support two SOPs. CTAs are divided into P-CTA and N-CTA, and P-CTA is divided into P-CTA1 and P-CTA2 because there are two SOPs. Here, the divided portions of the P-CTA do not operate at the same time as the divided portions of the beacons. PNC-1 secures two public CTAs (P-CTA1, P-CTA2) for Piconet-1 and Piconet-2, and the start time and duration of each P-CTA is determined by PNC-1.

Thereafter, the PNC-1 transmits the superframe adjustment information to the PNC-2 through the DEV-A (S160), and the PNC-1 and the PNC-2 transmit the beacon signal regarding the superframe coordination information of the common area. Transmit to all DEV (S170).

In step S130, the DEV existing in the common area but not receiving the beacon signal from the PNC-2 receives the beacon signal including the adjustment information of the superframe from the PNC-1 (S180).

Next, referring to FIG. 8, a second process S200 is described. Each DEV receiving a beacon signal transmitted from PNC-1 or PNC-2 is included in a common area based on the beacon signal. It is determined whether or not (S210).

As a result of the determination of step S210, the DEV included in the common area (hereinafter, 'P-DEV') transmits a signal to the PNC to which it belongs in the common area (S220), and the P-DEV is secured in step S150. After selecting any one of the P-CTA1 and P-CTA2, the channel time is requested (S230).

As a result of the determination of step S210, DEV (hereinafter referred to as 'N-DEV') not included in the common area transmits a channel status request signal to the PNC to which it belongs in order to check the channel state of the link existing in the common area. In operation S260, the N-DEV receives a response signal regarding a channel state of a link received from the PNC to determine whether interference occurs.

As a result of the determination in step S260, when the channel state of the link is good, the N-DEV determines that no interference has occurred and requests the channel time for communication from the N-CTA (S270), and the N-DEV channel state of the link. If it is not good, it is determined that the interference has occurred and selects any one of the P-CTA of P-CTA1 and P-CTA2 and requests the channel time (S230).

Accordingly, the PNC-1 and the PNC-2 allocate channel times for the DEVs to the P-CTA and the N-CTA (S300).

Here, the control format of the channel time request (CTRq) for supporting the P-CTA by the P-DEV will be described with reference to FIG. 9.

When the P-DEV sends a channel time request, the P-DEV executes a step of setting public to a CTRq control frame including a request signal, as shown. In other words, IEEE 802.15.3 supports the CTRq method allocated for each bit, and b3 supports reserved bits that can be changed according to the purpose. The public setting is supported through b3 to support P-CTA.

The present invention described above has proposed an interference cancellation method of piconets using intelligent channel time allocation, which can remove interference from overlapping regions of two piconets and facilitate communication between DEVs included in two piconets. Has the characteristics.

In order to illustrate the technical idea of the present invention, the two piconets are described and illustrated with respect to the overlapping case, but the present invention is not limited to the configuration and operation as described and described as described above. Obviously, the above piconets can be applied even when they are overlapped. Accordingly, all such suitable changes and modifications and equivalents should be considered to be within the scope of the present invention.

According to the present invention as described above, by using an intelligent channel time allocation (Intelligent CTA) method including a public channel time allocation (P-CTA) and a general channel time allocation (N-CTA), in the common area between piconets The interference generated can be eliminated, and the throughput of the piconet can be increased.

Claims (7)

A method of eliminating interference in a piconet using intelligent channel time allocation in a mobile communication system including a plurality of DEVs requesting channel time allocation and two or more PNCs allocating time for the DEVs according to a channel time allocation request, The PNC-1 adjusts the superframe to simultaneously operate the piconet-1 and piconet-2 having the common area, and the PNC-1 and PNC-2 receive all beacon signals including the superframe adjustment information of the common area. A first process of transmitting to the DEV (S100); The DEV receiving the beacon signal from the PNC-1 or PNC-2 determines whether it is included in the common area, and the P-DEV included in the common area requests a channel time from the P-CTA. (S200); And A third step (S300) in which the PNC-1 and the PNC-2 allocate a channel time according to the channel time request; Including, The first process, Receiving a beacon signal from the PNC-1 by a DEV present in a common region of piconet-1 and piconet-2 (S120); Determining whether the DEV present in the common area receives the beacon signal from the PNC-2 (S130); As a result of the determination of step S130, when receiving, operating the DEV existing in the common area as an intermediate DEV (S140); Adjusting a superframe in order to simultaneously operate Piconet-1 and Piconet-2 having the common area with PNC-1 (S150); Transmitting, by the PNC-1, the superframe adjustment information to the PNC-2 through an intermediary DEV (S160); And Transmitting, by the PNC-1 and the PNC-2, a beacon signal including superframe adjustment information of a common area to all DEVs (S170); Interference cancellation method of piconet using intelligent channel time allocation, characterized in that it comprises a. delete The method of claim 1, As a result of the determination in step S130, when the DEV present in the common area does not receive the beacon signal from the PNC-2, the DEV receives the beacon signal including the information on the superframe adjusted from the PNC-1. Step (S180); Method for removing interference of the piconet using intelligent channel time allocation, characterized in that it further comprises. The method of claim 1, Adjustment information of the super frame, At least among information divided into beacons B1 and B2 operating at different times, information divided into P-CTAs and N-CTAs, and information divided into P-CTAs and P-CTA2s. Piconet interference cancellation method using intelligent channel time allocation, characterized in that any one. The method of claim 1, The second process, Determining whether each DEV receiving the beacon signal transmitted from the PNC-1 or PNC-2 is included in the common area based on the beacon signal (S210); As a result of the determination in step S210, when included in the common region, the P-DEV transmits a signal indicating that the P-DEV is included in the common region (S220); And Requesting, by the P-DEV, any one of P-CTAs among P-CTA1 and P-CTA2, requesting a channel time from the selected P-CTA (S230); Interference cancellation method of piconet using intelligent channel time allocation, characterized in that it comprises a. The method of claim 5, As a result of the determination in step S210, if it is not included in the common area, the N-DEV not included in the common area transmits a channel state request signal of a link currently present in the common area to its PNC (S240). ; Transmitting, by the PNC, a response signal to a request signal to the N-DEV (S250); Determining, by the N-DEV, whether interference occurs on the channel based on the response signal received from the PNC (S260); And As a result of the determination in step S260, the N-DEV determines that no interference occurs when the channel state of the link is good, and requests the channel time to the N-CTA (S270), and when the channel state is not good, the interference occurs. Determining and selecting one of the P-CTAs of the P-CTA1 and the P-CTA2 and requesting a channel time (S230); Method for removing interference of the piconet using intelligent channel time allocation, characterized in that it further comprises. The method of claim 5, Before the step S230, The P-DEV setting a Public in a CTRq control frame; Method for removing interference of the piconet using intelligent channel time allocation, characterized in that it further comprises.

Images