KR100541640B1 - An Effective Method for a Child PNC to Communicate with a Target Device - Google Patents

Abstract

The present invention relates to a method and system for a child PNC to correctly communicate with a target device in a piconet operating under a wireless personal area network (PAN) environment.

The method according to the invention generates a command frame requesting a channel time for communicating with a second device using an identifier capable of identifying the piconet and a device ID uniquely assigned to the device and transmitting it to the parent PNC. step; A second step of allocating a channel time from the parent PNC receiving the request command frame so that the first device and the second device can communicate with each other; And a third step of transmitting and receiving data between the first device and the second device during the channel time.

According to the present invention, when a device belonging to a parent piconet and a child PNC of a child piconet wants to communicate with a device existing in a parent piconet or a child piconet, even if there is a duplicate device ID between the two devices, the device can correctly communicate. .

Piconet, PNC, child piconet, channel time allocation (CTA), PNID, Internal DEV Association Table

Description

An Effective Method for a Child PNC to Communicate with a Target Device}

1 is a block diagram illustrating an example in which a child PNC communicates according to a conventional IEEE 802.15.3 standard.

2 illustrates a hierarchical structure in accordance with IEEE 802.15.3 existing in each device.

Figure 3a is a view showing the "Internal DEV association table" owned by the child PNC according to the prior art.

3B illustrates an example of applying a PNID to an “Internal DEV association table” owned by a child PNC according to the present invention.

Figure 3c is a view showing another example of applying a PNID to the "Internal DEV association table" of the child PNC in accordance with the present invention.

4 is a diagram illustrating a difference when a PNID is applied in the same situation as in FIG. 1.

5 is a diagram illustrating a process of transmitting and receiving a command frame between a device and a PNC by applying a PNID.

6 is a flow chart showing the overall operation of the present invention.

The present invention relates to a method for transmitting and receiving data between devices in a wireless communication environment, and more particularly, a child PNC in a piconet operating under a wireless personal area network (PAN) environment with a target device. A method and system for communicating correctly.

In a wireless PAN, parent piconets and child piconets can coexist. As described above, when the parent piconet and the child piconet coexist, the frequency can be shared. However, in the generation of a MAC header for the child PNC to send a command frame or data frame to a specific target device, this coexistence may cause ambiguity.

1 is a block diagram illustrating an example in which a child PNC communicates according to a conventional IEEE 802.15.3 standard.

The PNC verifies that a device that is associated with a piconet at a given time has only one device ID (expressed as "DEVID" in the standard specification). Thus, virtually every associated device is assigned only one device ID.

The only exception to this is the PNC itself. A device operating as a PNC may have more than one device ID. A value whose device ID of the PNC is 0x00, that is, the PNCID is assigned to a PNC function associated with another device, and the other device ID value of the PNC is used for communication traffic (communication as a general device, not a PNC) that is not associated with the PNC.

When the piconet is started, the PNC assigns itself an additional device ID so that it can exchange data with other devices that are members of the newly created piconet.

As shown in Fig. 1, the parent piconet and the child piconet operate independently of each other. Thus, parent PNC and child PNC assign a unique device ID to devices in their piconet. As a result, devices with the same device ID may exist in the parent piconet and the child piconet.

In the situation as shown in FIG. 1, when the device # 4 140 existing in the parent piconet, that is, the child PNC, attempts to transmit a command frame to the device # 3 130 present in the parent piconet, the device # 4 140 It is not possible to generate the correct MAC header to perform this process. That is, since device # 4 140 has information about two devices # 3 130 and 230, it is impossible to generate a correct MAC header for command frame transmission.

The present invention proposes a method for removing the ambiguity generated in this way. That is, this problem is eliminated by adding a new primitive to the primitive specified in the prior art. The present invention eliminates this ambiguity and proposes a technique by which a child PNC can effectively communicate with a specific destination device desired.

A device operating in the parent piconet and simultaneously acting as a child PNC has both information about the devices in the parent piconet and the devices in the child piconet. Thus, when communicating with a particular destination device, due to the possible redundancy between these information, the MAC header for that device may not be generated correctly.

It is an object of the present invention to provide a method for enabling a device of a parent piconet and a device serving as a child PNC to effectively communicate with a specific destination device of interest.

In order to achieve the above object, a method in which a first device, which is a member of a parent piconet and a child PNC of a child piconet, communicates with the parent piconet or a second device present in the child piconet, the identifier capable of identifying the piconet. Generating a command frame requesting a channel time for communicating with a second device using a device ID uniquely assigned to the device and transmitting the same to a parent PNC; A second step of allocating a channel time from the parent PNC receiving the request command frame so that the first device and the second device can communicate with each other; And a third step of transmitting and receiving data between the first device and the second device during the channel time.

In order to achieve the above object, a piconet system in which a first device which is a member of a parent piconet and a child PNC of a child piconet communicates with the parent piconet or a second device present in the child piconet, can identify the piconet. A command frame that requests a channel time for communicating with a second device using an identifier that is uniquely assigned to the device and a device ID that is uniquely assigned to the device, sends it to the parent PNC, and communicates with the second device from the parent PNC. A first device assigned channel time; And a second device that receives a device ID from the child PNC or the parent PNC, and transmits and receives data with the first device during the channel time.

Hereinafter, exemplary embodiments of the present invention will be described in detail with reference to the accompanying drawings.

Referring to the stack structure of FIG. 2, a brief description will be given of how communication is performed between devices according to IEEE 802.15.3. First, the MAC layer 220 and the PHY physical layer 230 each have a management entity. This is called a MAC layer management entity (MLME) 240 and a PHY layer management entity (PLME) 250, respectively. These entities provide a service interface to perform layer management funtion at each layer.

In addition, a device management entity (DME) 260 must be present to perform the operation in the correct MAC. These DMEs operate independently for each layer, gathering layer-dependent status information for each layer from management entities in different layers, and similarly for layer-specific parameters. Has the function to set.

Various service access points (SAPs) serve as a gate for transferring information between the various entities. Information between PHY layer 230 and MAC layer 220 is conveyed by PHY SAP 203, and information between MAC layer 220 and FCSL 210 is conveyed by MAC SAP 202. The information between the DME 260 and the MLME 240 is transferred by the MLME SAP 204, and the information between the DME 260 and the PLME 250 is transferred by the PLME SAP 205. In addition, information between the MLME 240 and the PLME 250 is carried by the MLME-PLME SAP 206.

Figure 3a shows the "Internal DEV association table" of the child PNC according to the prior art. Each device uses the "Internal DEV Assocation Table" to store information for members in the same piconet. A device of a parent piconet and a child piconet of a child piconet is an internal device for storing information of members existing in the parent piconet and an internal DEV Assocation Table 310 for storing information of members existing in the parent piconet. It has an Association Table 320. Each table consists of fields including channel time allocation information, BSID, parent piconet information, device association (DEV association) information, and vendor specific information for each device. In some fields, there are subfields containing detailed information.

Each device has the field information, as indicated for each row. In the table 310 and the table 320, since a device having the same device ID exists, it is impossible to transmit data to a device in which the device ID is duplicated in a certain device.

Figure 3b shows an example of applying the PNID to the "Internal DEV association table" of the child PNC in accordance with the present invention. Both the PNID (Piconet ID) and the BSID (Beacon Source Identifier), defined in the 802.15.3 standard specification, are similar in that they are assigned per piconet. If the PNC finds another PNC that uses the same PNID or BSID, it changes the PNID or BSID. In this case, the PNID must be changed. However, the BSID does not necessarily need to be changed. In the standard specification, both cannot be changed at the same time. Therefore, using PNID as an identifier for identifying a piconet can be a more efficient and reliable method.

Accordingly, in the present invention, by adding a PNID to each "internal DEV association table" and adding and transmitting the PNID during various primitive exchanges, each device is uniquely identified even when there is a duplicate device ID (DEVID). Enable communication with the device. For example, if the child PNC wants to send data to device # 2 120 that is a member of the parent piconet, there are two devices with a device ID of 2 (120, 220), but the device ID is 1 and the PNID is Device 110, which is 0x06, is unique and can send data correctly.

As described above, in addition to the method of applying the PNID to the table itself, a method of using a table as another embodiment and writing the PNID for each row corresponding to each device may be considered. FIG. 3C illustrates an example of applying a PNID to the “Internal DEV association table” of the child PNC in this case. If the table is configured in this way, there is a disadvantage in that the PNID must be written for each row, but it is convenient because it can be managed as one table without having to have multiple tables for each piconet. By adding a PNID to each row representing each device of the "internal DEV association table" formed as described above, and adding and transmitting the PNID during various primitive exchanges, each device ID (DEVID) may be duplicated. It is possible to uniquely identify the device and to communicate with the device.

FIG. 4 illustrates a difference when PNID is applied in the situation as shown in FIG. 1. As in FIG. 1, if the child PNC 140 wants to transmit data to the device # 3 130 of the parent piconet, the device # 3 130 has a device ID of 3 in the " Internal DEV association table " It can be seen that the PNID is 1. Accordingly, since data is not duplicated with the device # 3 230 of the child piconet having the same device ID, data can be correctly transmitted.

FIG. 5 illustrates a process of transmitting and receiving a command frame between a device and a PNC by applying a PNID. In this figure, CREATE-STREAM is described as an example among primitives. The primitive is used by the device to request channel time from the PNC. First, the MLME-CREATE-STREAM.request 501 is generated by the DME 510 on the device side and delivered to the MLME 520.

The device 140 that is a device of the parent piconet and also serves as a child PNC of the child piconet is assigned a device ID # 4 from the parent PNC. The device # 4 140 uses a modified primitive MLME-CREATE-STREAM.request to communicate with a specific target device. The device # 4 140 has two " Internal DEV Assocation Table ", and these tables are divided into PNIDs. Thus, when a new parameter, PNID, is added to the primitive mentioned in the prior art, it is as follows. .

MLME-CREATE-STREAM.request {

   PNID,

   TrgtID,

   DSPSSetIndex,

   StreamRequestID,

   StreamIndex,

   …

   DesiredNumTUs,

   RequestTimeout

   }

The MLME 520 of the device # 4 140 generates a Channel Time Request command frame 502 to transmit to the MLME 530 of the parent PNC. At this time, since the PNID is included in the MLME-CREATE-STREAM.request 501 received from the DME 510 of the device # 4 140, a command frame having a correct MAC header can be generated.

The command frame 502 is included in a radio frequency (RF) signal to the air through the PHY layer and transmitted to the PNC. The RF signal is demodulated in the PHY layer on the PNC side, and the command frame 502 is extracted. The command frame 502 is passed to the MLME 530 of the PNC after passing through the MAC layer on the PNC side. The MLME 530 of the PNC, which has received the command frame 502, generates a frame confirming that the frame 502 has been received, that is, an Imm-ACK frame 503, and delivers it to the device side.

On the other hand, the command frame delivered to the MLME 530 of the PNC is delivered to the DME 540 of the PNC in the form of MLME-CREATE-STREAM.indication 504. The PNC's DME 540 then forwards the MLME-CREATE-STREAM.response 505 to the PNC's MLME 530 in response to the PME's MLME 530 being airborne through the MAC and PHY layers. Send an RF signal. The RF signal contains information of the CREATE-STREAM response command frame 506. The RF signal is demodulated in the PHY layer on the device side, and the command frame 506 is extracted. The command frame 506 passes through the MAC layer on the device side and then passes to the MLME 520 of the device. The MLME 520 of the device receiving the command frame 506 generates an Imm-ACK frame 507 confirming that the frame 506 has been received and transmits it to the PNC. Meanwhile, the command frame delivered to the MLME 520 of the device is delivered to the DME 510 of the device in the form of MLME-CREATE-STREAM.confirm 508.

As such, when device # 4 140 is confirmed to be able to communicate with a specific destination device from parent PNC 110, the PNC 110 communicates with device # 4 and the destination device via a beacon superframe. Allocate channel time, which is the time available. Thereafter, the device # 4 140 may communicate with the destination device during the channel time.

In the above example, the case where the primitive is CREATE-STREAM is an example, but in addition, MLME-DISASSOCIATE, MLME-MEMBERSHIP-UPDATE, MLME-PNC-HANDOVER, MLME-PNC-INFO, MLME-PROBE, and the like also include the added parameter PNID. To work.

6 is a flowchart showing the overall operation of the present invention.

The parent PNC allocates different device IDs to the members of the parent piconet, and the child PNC assigns different device IDs to the members of the child piconet (S610). At this time, the first device that is a member of the parent piconet and also serves as a child PNC is also assigned a device ID from the parent PNC. In this process, a duplicate device ID may be allocated between a device that is a parent piconet member and a device that is a child piconet member.

Next, information such as a device ID and a PNID of the second device is read from the "Internal DEV Assocation Table" of the first device (S620). The “Internal DEV Assocation Table” may be configured in a form in which each PNID is assigned to two tables as shown in FIG. 3B, or may be configured in a form in which a PNID is assigned to each column of one table as illustrated in FIG. 3C. have.

Next, MLME-CREATE-STREAM.request including the device ID and the PNID information of the destination device (second device) is generated (S630). The first device uses a device ID and PNID information of the destination device (second device) of the MLME-CREATE-STREAM.request to request a command frame for requesting a channel time for communicating with the destination device. Create and transmit it to the parent PNC (S640). Then, the parent PNC allocates a channel time so that the first device and the second device can communicate through the superframe of the beacon (S650). Thereafter, data is transmitted and received between the first device and the second device during the allocated channel time (S660).

Although embodiments of the present invention have been described above with reference to the accompanying drawings, those skilled in the art to which the present invention pertains may implement the present invention in other specific forms without changing the technical spirit or essential features thereof. I can understand that. Therefore, it should be understood that the embodiments described above are exemplary in all respects and not restrictive. The scope of the present invention is indicated by the scope of the following claims rather than the detailed description, and all changes or modifications derived from the meaning and scope of the claims and the equivalent concept are included in the scope of the present invention. Should be interpreted.

According to the present invention, when a device belonging to a parent piconet and a child PNC of a child piconet wants to communicate with a device existing in a parent piconet or a child piconet, even if there is a duplicate device ID between the two devices, the device can correctly communicate. .

Claims (10)

In a network environment in which a parent piconet and a child piconet coexist, a method in which a first device that is a member of a parent piconet and a PNC of a child piconet transmits data to the parent piconet or a second piconet belonging to a child piconet without confusion. A first step of recording a piconet identifier and a device ID for devices belonging to the parent piconet and devices belonging to the child piconet in a predetermined table of the first device; Identifying a piconet identifier of the second device and a device ID of the second device with reference to the table; A third step of assigning channel time from a parent PNC to communicate between the first device and the second device; And And transmitting a data including the identified piconet identifier and the device ID to the second device during the channel time. The method of claim 1, And the piconet identifier is a PNID defined in IEEE 802.15.3. The method according to claim 2, wherein before the third step Generating an MLME-CREATE-STREAM.request including a device ID and a piconet identifier of the second device as parameters; And Generating a command frame requesting a channel time for communicating with the second device using the generated MLME-CREATE-STREAM.request, and transmitting the command frame to the parent PNC; . The method of claim 3, wherein the table And a plurality of " Internal DEV Assocation Table ", wherein a unique PNID is described for each " Internal DEV Assocation Table ". The method of claim 3, wherein the table And a unique PNID for each piconet in each row of the " Internal DEV Assocation Table ". In a network environment in which a parent piconet and a child piconet coexist, a network system in which a first device that is a member of a parent piconet and a PNC of a child piconet can transmit data to the parent piconet or a second device belonging to a child piconet without confusion. A parent PNC for allocating channel time so that the first device and the second device can communicate; A piconet identifier and a device ID are recorded for devices belonging to the parent piconet and devices belonging to the child piconet in a predetermined table of the first device, and the piconet identifier and the second device of the second device are referenced with reference to the table. A first device identifying a device ID of two devices and transmitting data to the second device during the assigned channel time; And And a second device that receives data from the first device during the assigned channel time. The method of claim 6, And the piconet identifier is a PNID defined in IEEE 802.15.3. The method of claim 6, wherein the PNC is A device including a device ID and a piconet identifier of the second device, the command frame requesting a channel time for communicating with the first device and the second device from the first device and allocating the channel time accordingly; Piconet system, characterized in that. The method of claim 8, wherein the table A plurality of " Internal DEV Assocation Table ", wherein a unique PNID is described for each " Internal DEV Assocation Table ". The method of claim 8, wherein the table A piconet system comprising one " Internal DEV Assocation Table ", wherein a unique PNID is described for each piconet in each row of the " Internal DEV Assocation Table ".

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