JP2007208707A - Wireless lan device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To attain speeding up and increase in efficiency of a multicast packet in a wireless LAN device. <P>SOLUTION: In the wireless LAN device in which a wireless base station and a plurality of wireless terminals constitute a wireless LAN and the base station and the wireless terminals support a plurality of transmission rates used for communication, the wireless base station has a transmission rate storage means for storing transmission rates in communication of a wireless terminal in connection and a selection means for selecting the minimum transmission rate in transmission rates stored in the transmission rate storage means when the multicast packet is transmitted. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention relates to a wireless LAN device that transmits multicast packets between a wireless base station (AP) and a plurality of wireless terminals (STAs).

  Currently, the most widely used wireless LAN devices are based on the IEEE 802.11 standard. In this IEEE802.11 standard, for transmission of multicast packets or broadcast packets, one of the specified transmission rates (BSS basic rate set) among a plurality of transmission rates supported by a wireless base station (AP) and a plurality of wireless terminals (STAs). It is prescribed to use one (Non-Patent Document 1). For example, as shown in FIG. 19, in a wireless LAN apparatus in which a plurality of STAs 1 to 4 are connected to an AP and each transmit / receive unicast packets at transmission rates R6, R4, R6, and R6, the AP transmits multicast packets. In this case, conventionally, the minimum transmission rate of the BSS basic rate set (here, R1 in R5, R3, and R1) is fixedly used.

FIG. 20 shows a frame configuration example of a unicast packet and a multicast packet. In a unicast packet, a destination address is set in a field following frame control and duration ID. On the other hand, in the multicast packet, a multicast address is set in a field following frame control and duration ID, and the multicast packet is received by a predetermined STA.
IEEE Wireless LAN Edition, A compilation based on IEEE Std 802.11 TM-1999 (R2003) and its amendments

  In the wireless LAN device shown in FIG. 19, when an AP and a plurality of STAs support transmission rates R1 to R6 (BSS basic rate set R1, R3, R5 and options R2, R4, R6). Although R4 or R6 is used for transmission of unicast packets, R1 of the lowest rate is fixedly used for transmission of multicast packets on the premise of reception of all terminals. Therefore, the transmission time of the multicast packet is relatively longer than the transmission time of the unicast packet, and there is a problem that the radio line is occupied for a long time for transmission of the multicast packet.

  An object of the present invention is to provide a wireless LAN device capable of increasing the speed and efficiency of multicast packet transmission.

  A first aspect of the present invention is a wireless LAN device in which a wireless base station and a plurality of wireless terminals constitute a wireless LAN and support a plurality of transmission rates used for communication, respectively, and the wireless base station communicates with a connected wireless terminal. Transmission rate storage means for storing the transmission rate of the transmission rate, and selection means for selecting the minimum transmission rate among the transmission rates stored in the transmission rate storage means when the multicast packet is transmitted.

  Further, the selection means in the first invention is a transmission rate that is not more than the minimum transmission rate among the transmission rates stored in the transmission rate storage means, and is a prescribed transmission rate (a plurality of transmission rates supported by the wireless base station and the plurality of wireless terminals). BSS basic rate set) may be selected.

  The radio base station in the first invention includes communication end time storage means for storing a communication end time with the radio terminal, and the selection means is an elapsed time from the communication end time stored in the communication end time storage means. Alternatively, the minimum transmission rate of the wireless terminal that is equal to or less than a predetermined time may be selected.

  The radio base station according to the first aspect of the invention includes specifying means for specifying a wireless terminal that receives a multicast packet from a connected wireless terminal, and the selecting means is stored in the transmission rate storage means and specified by the specifying means. The minimum transmission rate of the wireless terminal may be selected.

  According to a second aspect of the present invention, in a wireless LAN device in which a wireless base station and a plurality of wireless terminals constitute a wireless LAN, when the wireless base station is connected to one wireless terminal, the multicast packet is addressed to that wireless terminal. Transmission means for converting the data into a unicast packet to be transmitted and not transmitting a multicast packet when there is no connected wireless terminal.

  Further, the radio base station in the second invention includes communication end time storage means for storing the communication end time with the radio terminal, and the transmission means is an elapsed time from the communication end time stored in the communication end time storage means. When a single wireless terminal has a predetermined time or less, the multicast packet is converted into a unicast packet destined for the wireless terminal, and the multicast packet is not transmitted when the wireless terminal does not exist. Also good.

  The radio base station according to the second aspect of the invention includes a specifying unit that specifies a radio terminal that receives a multicast packet from a connected radio terminal, and the transmission unit is provided when the number of radio terminals specified by the specifying unit is one. The multicast packet may be converted into a unicast packet destined for the wireless terminal and transmitted, and the multicast packet may not be transmitted when the wireless terminal does not exist.

  The radio base station according to the second invention includes a communication end time storage means for storing a communication end time with the radio terminal and a specifying means for specifying a radio terminal that receives a multicast packet from the connected radio terminal, The means is a wireless terminal whose elapsed time from the communication end time stored in the communication end time storage means is a predetermined time or less, and when there is one wireless terminal specified by the specifying means, the multicast packet is transmitted as the wireless terminal. It may be converted into a unicast packet destined for the terminal and transmitted, and the multicast packet may not be transmitted when the wireless terminal does not exist.

  A third invention is a wireless LAN device in which a wireless base station and a plurality of wireless terminals constitute a wireless LAN, and each supports a plurality of transmission rates used for communication, and the wireless base station communicates with a connected wireless terminal. A transmission rate storage means for storing the transmission rate of the network, and when the multicast packet is converted into a unicast packet and transmitted to the connected wireless terminal, a bandwidth occupancy rate corresponding to the transmission rate of the connected wireless terminal is calculated A bandwidth calculating means, a transmission means for determining whether or not the bandwidth occupancy affects other signal transmissions, and for converting and transmitting a multicast packet to a unicast packet when determined not to affect Prepare.

  According to a third aspect of the present invention, a radio base station includes a communication end time storage unit that stores a communication end time with a radio terminal, and the band calculation unit and the transmission unit include a communication end time stored in the communication end time storage unit. The processing corresponding to the third aspect of the invention may be performed for each wireless terminal whose elapsed time has been less than or equal to a predetermined time.

  The radio base station according to the third aspect of the invention includes a specifying unit that specifies a radio terminal that receives a multicast packet from a connected radio terminal, and the bandwidth calculation unit and the transmission unit specify the radio terminal specified by the specifying unit. As an object, processing corresponding to the third invention may be performed.

  The wireless LAN device according to the first aspect of the present invention fixedly selects the transmission rate of a multicast packet from the transmission rates of wireless terminals that satisfy a predetermined condition such as being connected to a wireless base station, thereby fixing the conventional BSS basic. Compared to the case where the minimum transmission rate of the rate set is selected, high-speed transmission is possible, and the occupied time of the radio line can be shortened.

  The wireless LAM device according to the second aspect of the invention converts a multicast packet into a unicast packet and transmits it at the transmission rate of the wireless terminal when there is one wireless terminal satisfying a predetermined condition such as being connected to a wireless base station. As a result, high-speed transmission is possible, and the time required for occupying a wireless line can be reduced. In addition, when there is no wireless terminal that satisfies the predetermined condition, unnecessary transmission of the wireless line can be prevented by stopping transmission of the multicast packet.

  The wireless LAM device according to the third aspect of the invention determines whether or not a multicast packet is converted into a unicast packet and transmitted when there are a plurality of wireless terminals that satisfy a predetermined condition such as being connected to a wireless base station. Then, when transmission is suitable, the multicast packet is converted into a unicast packet and transmitted at the transmission rate of each wireless terminal, thereby enabling high-speed transmission and shortening the occupied time of the wireless line.

(First embodiment)
FIG. 1 shows a first embodiment of the present invention. FIG. 1 (1) shows the configuration of the wireless LAN apparatus, and FIG. 1 (2) shows the configuration of the main part of the wireless base station AP according to this embodiment.

  In the figure, the wireless LAN device has a configuration in which a wireless base station AP and a plurality of wireless terminals STA1, STA2, STA3, and STA4 are connected. The AP and STA1 to STA4 support transmission rates R1 to R6 (BSS basic rate set R1, R3, and R5 and options R2, R4, and R6). Here, the transmission rates R6, R4, R6, and R6 are supported. It is assumed that a unicast packet is transmitted using The AP transmission rate storage means 11 stores the transmission rate at the time of communication of the STA connected to the AP. In this specification, “STA connected to AP” is an STA registered as a partner with which the AP can communicate, and the state where packets are actually being transmitted and received is “at the time of communication”.

  Here, when the AP transmits a multicast packet, the AP selection unit 12 sets the minimum transmission rate among the transmission rates stored in the transmission rate storage unit 11, that is, the minimum transmission rate of the connected STAs 1 to 4. Select. In this embodiment, since the minimum transmission rate is R4, the transmission rate R4 is selected when a multicast packet is transmitted. Conventionally, since the minimum transmission rate R1 of the BSS basic rate set has been selected in a fixed manner, it is possible to reduce the time taken to occupy the radio line by the amount that the transmission rate has increased.

(Second Embodiment)
FIG. 2 shows a second embodiment of the present invention.
The feature of this embodiment is that the AP selection means 12 in the configuration of the first embodiment has a BSS less than or equal to the minimum transmission rate in the transmission rate stored in the transmission rate storage means 11 when transmitting a multicast packet. There is a place to select the maximum transmission rate of basic rate set. That is, R3 which is the maximum transmission rate of R1, R3 and R5 of the BSS basic rate set is selected below the minimum transmission rate R4 of the connected STAs 1 to 4. Although this embodiment may have a slightly lower transmission rate than the first embodiment, it corresponds to the IEEE802.11 standard.

(Third embodiment)
FIG. 3 shows a third embodiment of the present invention.
In the configuration shown in the first embodiment, the AP transmission rate storage means 11 stores the transmission rate at the time of communication of the connected STAs 1 to 4, but stores the transmission rate until it is deleted after the communication ends. Yes. On the other hand, there are STAs that leave the AP area after the end of communication, and it is not reasonable to target such STAs when selecting the transmission rate of multicast packets.

  In order to exclude such STAs, the feature of this embodiment is that the AP includes a communication end time storage unit that stores a communication end time with the STA, and the AP selection unit 12 has an elapsed time from the communication end time. The transmission rate of multicast packets is selected for STAs with a predetermined time T or less. In the example of FIG. 3, the elapsed time from the communication end time t2 of the STA2 exceeds the predetermined time T, and the elapsed time from the communication end times t1, t3, t4 of the STA1, 3, 4 is less than the predetermined time T. Indicates the situation (including during communication). In this case, the AP selection means 12 selects only the STAs 1, 3, and 4 as the STA that transmits the multicast packet, and selects the minimum transmission rate R 6 among them.

(Fourth embodiment)
FIG. 4 shows a fourth embodiment of the present invention.
The feature of the present embodiment is that the AP selection means 12 in the configuration of the third embodiment is less than the STA minimum transmission rate at which the elapsed time from the communication end time is less than or equal to a predetermined time T when transmitting a multicast packet. Then, select the maximum transmission rate of BSS basic rate set. That is, R5 that is the maximum transmission rate of R1, R3, and R5 of the BSS basic rate set is selected below the minimum transmission rate R6 of STA1, 3, and 4. Although this embodiment may have a slightly lower transmission rate than the third embodiment, it corresponds to the IEEE802.11 standard.

(Fifth embodiment)
FIG. 5 shows a fifth embodiment of the present invention.
In the configuration shown in the first embodiment, when the STA that receives the multicast packet is specified in advance by the AP, it is reasonable to target the STA that does not receive the multicast packet when selecting the transmission rate of the multicast packet. is not.

  The feature of the present embodiment is that the AP includes a specifying unit that specifies a STA that receives a multicast packet in order to exclude a STA that does not receive the multicast packet. The place to select the packet transmission rate. In the example of FIG. 5, it is assumed that STAs 1, 2, and 4 receive multicast packets (MC), and AP selection means 12 targets only STAs 1, 2, and 4, and selects R4, which is the minimum transmission rate among them. To do. The AP may be configured to recognize the STA that receives the multicast packet from the information of the frame body of the multicast packet, or to manually set the STA that receives the multicast packet as the specifying unit.

(Sixth embodiment)
FIG. 6 shows a sixth embodiment of the present invention.
The feature of this embodiment is that the AP selection means 12 in the configuration of the fifth embodiment has a maximum transmission of the BSS basic rate set below the minimum transmission rate of the STA that receives the multicast packet when transmitting the multicast packet. There is a place to choose the rate. That is, R3 which is the maximum transmission rate of R1, R3 and R5 of the BSS basic rate set is selected below the minimum transmission rate R4 of STA1, 2, and 4. Although this embodiment may have a slightly lower transmission rate than the fifth embodiment, it corresponds to the IEEE802.11 standard.

(Seventh embodiment)
FIG. 7 shows a seventh embodiment of the present invention.
The feature of this embodiment is a combination of the third embodiment and the fifth embodiment. The AP selection unit 12 sets the transmission rate of the multicast packet for STAs whose elapsed time from the communication end time is equal to or less than the predetermined time T when transmitting the multicast packet and that receives the multicast packet. There is a place to choose. In the example of FIG. 7, the AP selection means 12 targets only STAs 1 and 4 and selects R6 which is the minimum transmission rate among them.

(Eighth embodiment)
FIG. 8 shows an eighth embodiment of the present invention.
A feature of the present embodiment is that the AP selecting means in the configuration of the seventh embodiment is an STA whose elapsed time from the communication end time is equal to or less than a predetermined time T when transmitting the multicast packet, and the multicast packet The maximum transmission rate of the BSS basic rate set is selected below the minimum transmission rate of the STA receiving the STA. That is, R5 which is the maximum transmission rate of R1, R3 and R5 of the BSS basic rate set is selected below the minimum transmission rate R6 of STA1 and 4. Although this embodiment may have a slightly lower transmission rate than the seventh embodiment, it corresponds to the IEEE 802.11 standard.

(Ninth embodiment)
FIG. 9 shows a ninth embodiment of the present invention. FIG. 10 shows the processing procedure of the AP in the ninth embodiment.

  In the figure, the transmission means of the AP where the multicast packet has arrived does not transmit the multicast packet when there is no STA connected to the AP (S1, S2, S3), and when there is one STA connected to the AP. The multicast packet is converted into a unicast packet and transmitted (S4, S5). In the example of FIG. 9, since only the STA 3 is connected to the AP, it is converted into a unicast packet at the transmission rate R6 and transmitted.

  When there are two or more STAs connected to the AP, multicast packet transmission processing is performed according to the procedure of any one of the first to eighth embodiments (S4, S6). However, in the process of S4, even when the number of STAs connected to the AP is 2 or more, the STA whose elapsed time from the communication end time is equal to or less than the predetermined time T, or the STA that receives the multicast packet is one. May convert a multicast packet into a unicast packet for transmission. This case will be described in the tenth, eleventh, and twelfth embodiments described below.

(Tenth embodiment)
FIG. 11 shows a tenth embodiment of the present invention.
As in the third embodiment, the feature of the present embodiment is that the AP includes communication end time storage means for storing the communication end time with the STA, and the transmission means of the AP has elapsed time from the communication end time for a predetermined time. The control shown in the ninth embodiment is performed for STAs of T or less. In the example of FIG. 11, the STA 1, 2, 4 has elapsed time from the communication end time exceeds the predetermined time T, and only the STA 3 has elapsed time from the communication end time less than the predetermined time T (even during communication). Including). In this case, the AP transmission means converts the multicast packet into a unicast packet for STA3 and transmits it at the transmission rate R6.

(Eleventh embodiment)
FIG. 12 shows an eleventh embodiment of the present invention.
As in the fifth embodiment, the feature of the present embodiment is that the AP includes a specifying unit that specifies a STA that receives a multicast packet, and the ninth embodiment is directed to the STA in which the AP transmitting unit is specified. The control shown in is performed. The example of FIG. 12 shows a situation where the terminal that receives the multicast packet is only STA3. In this case, the AP transmission means converts the multicast packet into a unicast packet for STA3 and transmits it at the transmission rate R6.

(Twelfth embodiment)
FIG. 13 shows a twelfth embodiment of the present invention.
The feature of this embodiment is a combination of the tenth embodiment and the eleventh embodiment. When the elapsed time from the communication end time is equal to or shorter than the predetermined time T and the number of STAs that receive the multicast packet is one, the AP transmission means converts the multicast packet into a unicast packet and transmits it to the STA. In the example of FIG. 13, the STAs 2 and 3 receive an elapse time from the communication end time that is equal to or less than the predetermined time T, and the STAs 1 and 3 receive the multicast packet. Only the STA 3 receives the multicast packet at the time T or less. In this case, the AP transmission means converts the multicast packet into a unicast packet for STA3 and transmits it at the transmission rate R6.

(13th Embodiment)
FIG. 14 shows a thirteenth embodiment of the present invention. FIG. 14 (1) shows the configuration of the wireless LAN device, and FIG. 14 (2) shows the configuration of the main part of the wireless base station AP according to this embodiment. FIG. 15 shows the processing procedure of the AP in the thirteenth embodiment.

  In FIG. 14, the wireless LAN device has a configuration in which a wireless base station AP and a plurality of wireless terminals STA1 and STA3 are connected and the wireless terminals STA2 and STA4 are not connected. APs and STAs 1 and 3 support transmission rates R1 to R6 (BSS basic rate set R1, R3, and R5 and options R2, R4, and R6). Here, unicast packets are transmitted at transmission rates R6 and R6. Is transmitted. The AP transmission rate storage means 11 stores the transmission rate at the time of communication of the STA connected to the AP.

  Here, the AP that has received the multicast packet does not transmit the multicast packet when there is no STA connected to the AP (FIG. 15: S11, S12, S13). On the other hand, when there is an STA connected to the AP and it is determined whether or not the multicast packet is converted into a unicast packet and can be transmitted, the AP bandwidth calculation means 13 determines the bandwidth according to the transmission rate of the connected STA. The occupancy rate W is calculated, and the transmission means 14 compares it with a specified value A indicating whether or not the band occupancy rate W affects other signal transmissions (FIG. 15: S14). When the bandwidth occupancy W is equal to or greater than the specified value A (when other signal transmission is affected), it is transmitted as a multicast packet (FIG. 15: S15), and when the bandwidth occupancy W is less than the specified value A (others) Multicast signal is converted into a unicast packet and transmitted (FIG. 15: S16).

  In the example shown in FIG. 14, if the bandwidth occupancy W when the unicast packets are sequentially transmitted to the two STAs 1 and 3 at the respective transmission rates R6 and R6 exceeds the specified value A, the multicast packets are transmitted as specified. If it becomes less than the value A, it is converted into a unicast packet and transmitted to STA1 and STA3 sequentially. In the present embodiment, when the transmission rate of each STA is higher than the transmission rate when transmitting by multicast packets, transmission as unicast packets is more efficient.

(Fourteenth embodiment)
FIG. 16 shows a fourteenth embodiment of the present invention.
As in the third embodiment, the feature of the present embodiment is that the AP includes communication end time storage means for storing the communication end time with the STA, and the transmission means of the AP has elapsed time from the communication end time for a predetermined time. The control shown in the thirteenth embodiment is performed for STAs of T or less. In the example of FIG. 16, the STA2 and 4 have elapsed time from the communication end time exceeds the predetermined time T, and the STA1 and 3 have elapsed time from the communication end time is equal to or less than the predetermined time T (including during communication). ). In this case, for the STAs 1 and 3, the AP determines whether or not the multicast packet in the thirteenth embodiment is converted into a unicast packet and is transmitted, and performs corresponding processing.

(Fifteenth embodiment)
FIG. 17 shows a fifteenth embodiment of the present invention.
As in the fifth embodiment, the feature of the present embodiment is that the AP includes a specifying unit that specifies a STA that receives a multicast packet, and the thirteenth embodiment is directed to the STA in which the AP transmitting unit is specified. The control shown in is performed. The example of FIG. 17 shows a situation where the terminals that receive the multicast packet are STAs 1 and 3. In this case, for the STAs 1 and 3, the AP determines whether or not the multicast packet in the thirteenth embodiment is converted into a unicast packet and is transmitted, and performs corresponding processing.

(Sixteenth embodiment)
FIG. 18 shows a sixteenth embodiment of the present invention.
The feature of this embodiment is a combination of the fourteenth, the fifteenth and the fifteenth embodiments. The transmission means of the AP performs the control shown in the thirteenth embodiment for STAs whose elapsed time from the communication end time is equal to or shorter than the predetermined time T and receiving multicast packets. In the example of FIG. 18, the STAs 1, 3, and 4 have an elapsed time from the communication end time that is equal to or less than the predetermined time T, and the STAs 1, 2, and 3 receive multicast packets. The fact that the elapsed time is less than or equal to the predetermined time T and the multicast packet is received indicates the situation of STA1 and STA3. In this case, for the STAs 1 and 3, the AP determines whether or not the multicast packet in the thirteenth embodiment is converted into a unicast packet and is transmitted, and performs corresponding processing.

  The process of converting to a unicast packet when there is one connected STA shown in the ninth to twelfth embodiments, and the unicast packet when there are a plurality of connected STAs shown in the thirteenth to sixteenth embodiments. It is also possible to combine the processing of converting to.

The figure which shows the 1st Embodiment of this invention. The figure which shows the 2nd Embodiment of this invention. The figure which shows the 3rd Embodiment of this invention. The figure which shows the 4th Embodiment of this invention. The figure which shows the 5th Embodiment of this invention. The figure which shows the 6th Embodiment of this invention. The figure which shows the 7th Embodiment of this invention. The figure which shows the 8th Embodiment of this invention. The figure which shows the 9th Embodiment of this invention. The flowchart which shows the process sequence of AP in 9th Embodiment. The figure which shows the 10th Embodiment of this invention. The figure which shows the 11th Embodiment of this invention. The figure which shows the 12th Embodiment of this invention. The figure which shows the 13th Embodiment of this invention. The flowchart which shows the process sequence of AP in 13th Embodiment. The figure which shows 14th Embodiment of this invention. The figure which shows 15th Embodiment of this invention. The figure which shows the 16th Embodiment of this invention. The figure which shows the structural example of the conventional wireless LAN apparatus. The figure which shows the example of a frame structure.

Explanation of symbols

AP radio base station STA radio terminal 11 transmission rate storage means 12 selection means 13 bandwidth calculation means 14 transmission means

Claims (11)

In a wireless LAN device that includes a wireless base station and a plurality of wireless terminals constituting a wireless LAN and supports a plurality of transmission rates used for communication, respectively,
The radio base station is
Transmission rate storage means for storing a transmission rate during communication of the wireless terminal being connected;
A wireless LAN device, comprising: a selection unit that selects a minimum transmission rate among transmission rates stored in the transmission rate storage unit when a multicast packet is transmitted. The wireless LAN device according to claim 1,
The selection means is a minimum transmission rate in a transmission rate stored in the transmission rate storage means, and a prescribed transmission rate (BSS basic rate) in a plurality of transmission rates supported by the wireless base station and the plurality of wireless terminals. A wireless LAN device characterized by selecting a maximum transmission rate of set). The wireless LAN device according to claim 1,
The radio base station includes a communication end time storage unit that stores a communication end time with the radio terminal, and the selection unit has a predetermined time elapsed from the communication end time stored in the communication end time storage unit. A wireless LAN device that selects a minimum transmission rate of a wireless terminal that is: The wireless LAN device according to claim 1,
The radio base station includes specifying means for specifying a wireless terminal that receives the multicast packet from the connected wireless terminal, and the selecting means is stored in the transmission rate storage means and specified by the specifying means A wireless LAN device that selects a minimum transmission rate of a wireless terminal. In a wireless LAN device in which a wireless base station and a plurality of wireless terminals constitute a wireless LAN,
The wireless base station converts a multicast packet to a unicast packet destined for the wireless terminal when the wireless terminal being connected is one, and transmits the unicast packet when the wireless terminal is not connected. A wireless LAN device comprising a transmission means that does not transmit a multicast packet. The wireless LAN device according to claim 5,
The radio base station includes a communication end time storage unit that stores a communication end time with the radio terminal, and the transmission unit has a predetermined time elapsed from the communication end time stored in the communication end time storage unit. When there is one wireless terminal, the multicast packet is converted into a unicast packet destined for the wireless terminal and transmitted, and the multicast packet is not transmitted when the wireless terminal does not exist Wireless LAN device. The wireless LAN device according to claim 5,
The wireless base station includes specifying means for specifying a wireless terminal that receives the multicast packet from the connected wireless terminal, and the transmitting means is configured to perform multicasting when there is one wireless terminal specified by the specifying means. A wireless LAN device, wherein a packet is converted into a unicast packet destined for the wireless terminal and transmitted, and the multicast packet is not transmitted when the wireless terminal does not exist. The wireless LAN device according to claim 5,
The radio base station includes a communication end time storage unit that stores a communication end time with the radio terminal and a specifying unit that specifies a radio terminal that receives the multicast packet from the connected radio terminal, and the transmission unit includes A wireless terminal whose elapsed time from the communication end time stored in the communication end time storage means is equal to or less than a predetermined time, and when there is one wireless terminal specified by the specifying means, A wireless LAN device, wherein the wireless LAN device converts to a unicast packet destined for a terminal and transmits the packet, and does not transmit the multicast packet when the wireless terminal does not exist. In a wireless LAN device that includes a wireless base station and a plurality of wireless terminals constituting a wireless LAN and supports a plurality of transmission rates used for communication, respectively,
The radio base station is
Transmission rate storage means for storing a transmission rate during communication of the wireless terminal being connected;
Bandwidth calculation means for calculating a bandwidth occupancy rate according to the transmission rate of the connected wireless terminal when the multicast packet is converted into a unicast packet and transmitted to the connected wireless terminal;
A transmission unit that determines whether or not the bandwidth occupancy affects other signal transmissions, and converts the multicast packet into a unicast packet when it is determined that it does not affect the transmission; A wireless LAN device characterized by the above. The wireless LAN device according to claim 9, wherein
The radio base station includes a communication end time storage unit that stores a communication end time with the radio terminal, and the bandwidth calculation unit and the transmission unit are connected to the communication end time stored in the communication end time storage unit. A wireless LAN device characterized in that the corresponding processing shown in claim 9 is performed for each wireless terminal whose elapsed time is a predetermined time or less. The wireless LAN device according to claim 9, wherein
The radio base station includes a specifying unit that specifies a radio terminal that receives the multicast packet from the connected radio terminal, and the bandwidth calculation unit and the transmission unit target the radio terminal specified by the specifying unit. As a wireless LAN device, the corresponding processing shown in claim 9 is performed.

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