INCREASING PROBABILITY OF MULTICAST TRANSMISSIONS IN WLAN
A network device detects a multicast video stream being from an upstream resource being sent to downstream multicast members. If the number of multicast members are below a threshold (e.g., 5 stations), multicast network packets can be converted to unicast network packets. On the other hand, if the number of multicast members are above the threshold, the multicast members are divided into groupings based on capabilities of the multicast members, such as data rate capability. Data rates of transmissions are set according to the group data rate capabilities. As a result, the higher data rate members are able to operate at a higher speed rather than at the lowest common denominator. Further, because there are several multicast streams being sent, packets missed from the higher data rate stream can be picked up on the lower data rate stream.
1 . A computer-implemented method in a network device of a data communication network, for increasing delivery probability of multicast video transmissions, the method comprising the steps of:
detecting, by a processor of the network device, a video stream within a multicast transmission of network packets to multicast members;
responsive to a number of multicast members being below a threshold, converting, by the processor, the multicast transmission to a plurality of unicast transmissions, wherein the unicast transmission provides an acknowledgment for received network packets from the multicast members;
responsive to the number of multicast members meeting or exceeding the threshold:
determining, by the processor, data rate capabilities for each of the multicast members,
grouping the multicast members into two or more groups based on corresponding data rate capabilities, and
generating a multicast stream for each of the groups at distinct data rates; and
sending, by a network interface of the network device, two or more multicast transmissions downstream to the multicast members groups at the distinct data rates.
2 . The method of claim 1 , further comprising:
determining an amount of computing resources needed by the network device to facilitate different numbers of unicast transmissions; and
setting the threshold for the number of multicast members based on the determined amount of computing resources needed for the plurality of unicast transmissions.
3 . The method of claim 1 , further comprising:
prior to detecting the video stream, receiving the video stream from a remote server.
4 . The method of claim 1 , wherein the multicast members comprise end station devices.
5 . The method of claim 1 , further comprising:
tracking the number of multicast members;
detecting that the number of multicast members has crossed or will soon cross the threshold; and
dynamically changing between a unicast mode and a data rate grouping mode, responsive to the detection.
6 . The method of claim 1 , wherein responsive to the number of multicast members meeting or exceeding the threshold:
detecting high priority network packets, including I and P frames from an MPEG format of video multicast; and
automatically retransmitting at least some of the I and P frames.
7 . A non-transitory computer-readable medium, storing source code that, when executed by a processor, performs a method in a network device of a data communication network, for increasing delivery probability of multicast video transmissions, the method comprising the steps of:
detecting, by a processor of the network device, a video stream within a multicast transmission of network packets to multicast members;
responsive to a number of multicast members being below a threshold, converting, by the processor, the multicast transmission to a plurality of unicast transmissions, wherein the unicast transmission provides an acknowledgment for received network packets from the multicast members;
responsive to the number of multicast members meeting or exceeding the threshold:
determining, by the processor, data rate capabilities for each of the multicast members,
grouping the multicast members into two or more groups based on corresponding data rate capabilities, and
generating a multicast stream for each of the groups at distinct data rates; and
sending, by a network interface of the network device, two or more multicast transmissions downstream to the multicast members groups at the distinct data rates.
8 . The computer-readable medium of claim 7 , the method further comprising:
determining an amount of computing resources needed by the network device to facilitate different numbers of unicast transmissions; and
setting the threshold for the number of multicast members based on the determined amount of computing resources needed for the plurality of unicast transmissions.
9 . The computer-readable medium of claim 7 , the method further comprising:
prior to detecting the video stream, receiving the video stream from a remote server.
10 . The computer-readable medium of claim 7 , wherein the multicast members comprise end station devices.
11 . The computer-readable medium of claim 7 , the method further comprising:
tracking the number of multicast members;
detecting that the number of multicast members has crossed or will soon cross the threshold; and
dynamically changing between a unicast mode and a data rate grouping mode, responsive to the detection.
12 . The computer-readable medium of claim 7 , the method further comprising, wherein responsive to the number of multicast members meeting or exceeding the threshold:
detecting high priority network packets, including I and P frames from an MPEG format of video multicast; and
automatically retransmitting at least some of the I and P frames.
13 . A network device of a data communication network, for increasing delivery probability of multicast video transmissions, the network device comprising:
a processor;
a video multicast detection module, communicatively coupled to the processor, the video multicast detection module to detect a video stream within a multicast transmission of network packets to multicast members;
a unicast conversion module, communicatively coupled to the processor and the video multicast detection module, the unicast conversion module 220 to, responsive to a number of multicast members being below a threshold, convert the multicast transmission to a plurality of unicast transmissions, wherein the unicast transmission provides an acknowledgment for received network packets from the multicast members;
a data rate grouping module, communicatively coupled to the processor and the unicast conversion module to, responsive to the number of multicast members meeting or exceeding the threshold:
determine data rate capabilities for each of the multicast members,
group the multicast members into two or more groups based on corresponding data rate capabilities, and
generate a multicast stream for each of the groups at distinct data rates; and
a network interface, communicatively coupled to the network interface and the unicast conversion module and to the data rate grouping module, the network interface to send two or more multicast transmissions downstream to the multicast members groups at the distinct data rates.