Method and apparatus for multicasting/broadcasting in relay network of wireless LAN system
The present disclosure relates to a wireless communication system and, more particularly, to a method and apparatus for multicasting/broadcasting in a relay network of a wireless LAN system. A method by which a relay entity delivers a multicast/broadcast frame in a wireless LAN system, according to one embodiment of the present disclosure, includes the steps of: receiving a multicast/broadcast frame from an STA; and delivering the multicast/broadcast frame to a root access point (AP). The multicast/broadcast frame may be transmitted by the root AP in a broadcast scheme within a basic service set (BSS). In the multicast/broadcast frame transmitted in the broadcast scheme by the root AP, an address 1 (A 1 ) field may be set to a multicast/broadcast address, an Address 2 (A 2 ) field may be set to a medium access control (MAC) address of the root AP, and an Address 3 (A 3 ) field may be set as a MAC address of the STA, which is a source address of the multicast/broadcast frame.
1. A method for delivering a multicast/broadcast frame by a relay entity in a wireless local area network (WLAN) system, the method comprising:
receiving the multicast/broadcast frame from a station (STA); and
delivering the multicast/broadcast frame to a root access point (root AP),
wherein the multicast/broadcast frame is broadcast by the root AP within a basic service set (BSS),
wherein the multicast/broadcast frame broadcast by the root AP comprises:
an Address 1 (A 1 ) field set to a multicast/broadcast address;
an Address 2 (A 2 ) field set to a medium access control (MAC) address of the root AP; and
an Address 3 (A 3 ) field set to a MAC address of the STA, the MAC address being a source address of the multicast/broadcast frame, and
wherein, upon receiving the multicast/broadcast frame broadcast by the root AP, an STA having an address identical to the source address of the multicast/broadcast frame broadcast by the root AP discards the multicast/broadcast frame broadcast by the root AP.
2. The method according to claim 1 , wherein, when the multicast/broadcast frame delivered to the root AP is an aggregate-MAC service data unit (A-MSDU) frame,
the A-MSDU frame comprises:
an A 1 field set to the MAC address of the root AP;
an A 2 field set to a MAC address of the relay entity; and
an A 3 field set to a basic service set identifier (BSSID),
wherein an A-MSDU subframe of the A-MSDU frame comprises:
a destination address (DA) field set to the multicast/broadcast address; and
a source address (SA) field set to the MAC address of the STA, the MAC address being the source address of the multicast/broadcast frame.
3. The method according to claim 1 , wherein, when the multicast/broadcast frame delivered to the root AP has four address fields,
the four address fields comprises:
an A 1 field set to the MAC address of the root AP;
an A 2 field set to a MAC address of the relay entity;
an A 3 field set to the multicast/broadcast address; and
an A 4 (Address 4 ) field set to the MAC address of the STA, the MAC address being the source address of the multicast/broadcast frame.
4. The method according to claim 1 , wherein
the multicast/broadcast frame, which is received by the relay entity, is delivered to the relay entity by the STA as a unicast transmission rather than being broadcast.
5. The method according to claim 1 , wherein, the multicast/broadcast frame, which is received from the STA, is delivered to the root AP by the relay entity as a unicast transmission rather than being broadcast.
6. The method according to claim 1 , wherein the STA is associated with the relay entity.
7. The method according to claim 1 , wherein the relay entity is associated with the AP.
8. A relay for delivering a multicast/broadcast frame in a wireless local area network (WLAN) system, the relay comprising:
a transceiver; and
a processor, that controls the transceiver to:
receive the multicast/broadcast frame from a station (STA); and
deliver the multicast/broadcast frame to a root access point (root AP),
wherein the multicast/broadcast frame is broadcast by the root AP within a basic service set (BSS),
wherein the multicast/broadcast frame broadcast by the root AP comprises:
an Address 1 (A 1 ) field set to a multicast/broadcast address;
an Address 2 (A 2 ) field set to a medium access control (MAC) address of the root AP; and
an Address 3 (A 3 ) field set to a MAC address of the STA, the MAC address being a source address of the multicast/broadcast frame,
wherein, upon receiving the multicast/broadcast frame broadcast by the root AP, an STA having an address identical to the source address of the multicast/broadcast frame broadcast by the root AP discards the multicast/broadcast frame broadcast by the root AP.
9. The relay according to claim 8 , wherein, when the multicast/broadcast frame delivered to the root AP is an aggregate-MAC service data unit (A-MSDU) frame,
the A-MSDU frame comprises:
an A 1 field set to the MAC address of the root AP;
an A 2 field set to a MAC address of the relay entity; and
an A 3 field set to a basic service set identifier (BSSID),
wherein an A-MSDU subframe of the A-MSDU frame comprises:
a destination address (DA) field set to the multicast/broadcast address; and
a source address (SA) field set to the MAC address of the STA, the MAC address being the source address of the multicast/broadcast frame.
10. The relay according to claim 8 , wherein, when the multicast/broadcast frame delivered to the root AP has four address fields,
the four address fields comprises:
an A 1 field set to the MAC address of the root AP;
an A 2 field set to a MAC address of the relay entity;
an A 3 field set to the multicast/broadcast address; and
an A 4 (Address 4 ) field set to the MAC address of the STA, the MAC address being the source address of the multicast/broadcast frame.
11. The relay according to claim 8 , wherein the multicast/broadcast frame, which is received by the relay entity, is delivered to the relay entity by the STA as a unicast transmission rather than being broadcast.
12. The relay according to claim 8 , wherein the multicast/broadcast frame, which is received from the STA, is delivered to the root AP by the relay entity as a unicast transmission rather than being broadcast.
13. The relay according to claim 8 , wherein the STA is associated with the relay entity.
14. The relay according to claim 8 , wherein the relay entity is associated with the AP.