# US 8,787,238 B2 · Method for retransmitting multicast frames and method for processing received multicast frames in wireless network

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- Number: US 8,787,238 B2
- Document ID: US8787238B2
- Status: Granted
- Kind: B2
- Application number: 13/707,225
- Filed: 2012-12-06
- Published: 2013-04-18
- Granted: 2014-07-22
- Earliest claimed: 2007-10-10
- Assignees: LG Electronics Inc.
- Applicants: LG Electronics Inc.
- Inventors: Yongho Seok
- Web page: https://patentgrep.com/patent/US8787238B2

## CPC

- H04L 12/189: {in combination with wireless systems (selective distribution or broadcast in wireless communication networks H04W4/06)}
- H04L 1/1829: Arrangements specially adapted for the receiver end
- H04L 1/1887: {Scheduling and prioritising arrangements}
- H04L 2001/0093: {Point-to-multipoint}
- H04L: TRANSMISSION OF DIGITAL INFORMATION, e.g. TELEGRAPHIC COMMUNICATION (arrangements common to telegraphic and telephonic communication H04M)

## Abstract

A method for retransmitting a multicast frame in a wireless network and for determining whether a received multicast frame is a duplicated frame. In determining whether the received multicast frame is the same duplicated frame as a previously received multicast frame, a receiver address value and a sequence number of the multicast frame may be used. When fragmentation of a multicast frame is allowed, the value of a fragment number of the multicast frame may be also used, and if it includes a traffic ID, the value of the traffic ID can be also used for determining whether or not the multicast frame is a duplicated frame. If a multicast frame is transmitted in a wireless mesh network, it is determined whether or not the multicast frame is a duplicated one by using a mesh source address, a mesh destination address, and a sequence number.

## Claims

### Claim 1

A method of multicasting data in a wireless communication network, comprising:
transmitting, by a transmitter, a first multicasting frame, the first multicasting frame including a first receiver address, a first transmitter address and a first retry bit, the first receiver address including a first multicasting address, the first retry bit being set to zero; and
transmitting, by the transmitter, a second multicasting frame, the second multicasting frame including a second receiver address, a second transmitter address and a second retry bit, the second receiver address including a second multicasting address, the second transmitter address being same as the first transmitter address, the second retry bit being set to one,
wherein, if the second multicasting frame is a retransmission of the first multicasting frame, the second multicasting address is different from the first multicasting address,
wherein the first and second multicasting addresses each include a corresponding plurality of bits, and
wherein at least one bit of the second multicasting address is set to a different value than at least corresponding bit of the first multicasting address so that a legacy receiving device which does not support multicast retransmission does not process the second multicasting frame.

### Claim 2 (depends on 1)

The method of claim 1, wherein the second multicasting frame further includes a destination address including the first multicasting address.

### Claim 3 (depends on 1)

The method of claim 1, wherein the second multicasting frame is transmitted without receiving a request for the retransmission of the first multicasting frame.

### Claim 4 (depends on 1)

The method of claim 1, wherein the second multicasting address is a predetermined multicasting address.

### Claim 5

An apparatus for transmitting multicast data in a wireless communication network, the apparatus comprising:
a transmitting device configured to
transmit a first multicasting frame, the first multicasting frame including a first receiver address, a first transmitter address and a first retry bit, the first receiver address including a first multicasting address, the first retry bit being set to zero, and
transmit a second multicasting frame, the second multicasting frame including a second receiver address, a second transmitter address and a second retry bit, the second receiver address including a second multicasting address, the second transmitter address being same as the first transmitter address, the second retry bit being set to one,
wherein, if the second multicasting frame is a retransmission of the first multicasting frame, the second multicasting address is different from the first multicasting address,
wherein the first and second multicasting addresses include a corresponding plurality of bits, and
wherein at least one bit of the second multicasting address is set to a different value than at least corresponding bit of the first multicasting address so that a legacy receiving device which does not support multicast retransmission does not process the second multicasting frame.

### Claim 6 (depends on 5)

The apparatus of claim 5, wherein the second multicasting frame further includes a destination address including the first multicasting address.

### Claim 7 (depends on 5)

The apparatus of claim 5, wherein the second multicasting frame is transmitted without receiving a request for the retransmission of the first multicasting frame.

### Claim 8 (depends on 5)

The apparatus of claim 5, wherein the second multicasting address is a predetermined multicasting address.