Powerline network flood control restriction
View Patent ↗A transmit process that limits the time during which a reduced network bandwidth exists between two powerline nodes because a receiving node fails to respond to frame transmission attempts by a transmitting node is described. The transmit process restricts the number of retries that occur in a lower date rate transmission mode and, for a predetermined time period to follow, drops all subsequent frames destined for the non-responding node.
1. In a network of nodes, each node having a transmitter and a receiver, a method of operating a transmitter in a node comprises:
transmitting, in at least one transmission attempt, a frame over a shared channel to a receiver in another node, the frame being of the type for which a response is expected;
determining if no response is received from the receiver;
discarding the frame; and
discarding any subsequent frames destined for the receiver without any transmission attempt for a predetermined time interval.
2. The method of claim 1 , further comprising:
transmitting the frame to the receiver in reduced data rate transmission attempts until a threshold number of such reduced data rate transmission attempts have occurred without a response from the receiver.
3. The method of claim 1 , wherein the shared channel is a powerline-based communications channel.
4. The method of claim 1 , wherein the shared channel is an Ethernet-based communications channel.
5. The method of claim 1 , further comprising:
setting a timer to run for the duration of the predetermined time interval when the frame is discarded; and
causing a flag associated with the address of the receiver to be set while the timer is running.
6. The method of claim 5 , wherein discarding any subsequent frames comprises:
determining that each such subsequent frame is destined for the receiver;
determining, for each such subsequent frame destined for the receiver, if the flag is set for the receiver; and
discarding each such subsequent frame when it is determined that the flag is set for the receiver.
7. A computer program residing on a computer-readable medium for operating a transmitter in a node in a network of nodes each having a transmitter and a receiver, the computer program comprising instructions causing a computer to:
transmit, in at least one transmission attempt, a frame over a shared channel to a receiver in another node, the frame being of the type for which a response is expected;
determine if no response is received from the receiver;
discard the frame; and
discard any subsequent frames destined for the receiver without any transmission attempt for a predetermined time interval.
8. In a network of nodes, each node having a transmitter and a receiver, a transmitter in a node comprising:
means for transmitting, in at least one transmission attempt, a frame over a shared channel to a receiver in another node, the frame being of the type for which a response is expected;
means for determining if no response is received from the receiver;
means for discarding the frame; and
means for discarding any subsequent frames destined for the receiver without any transmission attempt for a predetermined time interval.
9. The transmitter of claim 8 , further comprising:
means for transmitting the frame to the receiver in reduced data rate transmission attempts until a threshold number of such reduced data rate transmission attempts have occurred without a response from the receiver.
10. The transmitter of claim 8 , wherein the shared channel is a powerline-based communications channel.
11. The transmitter of claim 8 , wherein the shared channel is an Ethernet-based communications channel.
12. The transmitter of claim 8 , further comprising:
means for setting a timer to run for the duration of the predetermined time interval when the frame is discarded; and
means for causing a flag associated with the address of the receiver to be set while the timer is running.
13. The transmitter of claim 12 , wherein means for discarding any subsequent frames comprises:
means for determining that each such subsequent frame is destined for the receiver;
means for determining, for each such subsequent frame destined for the receiver, if the flag is set for the receiver; and
means for discarding each such subsequent frame when it is determined that the flag is set for the receiver.
14. A media access control device for use in nodes in a powerline network, comprising:
a transmitter for transmitting frames onto the powerline network;
a control block coupled to the transmitter, the control block including a timer and a table for associating nodes on the powerline network with control information, the control information including a flag to indicate that the timer is running;
wherein the transmitter is operable to transmit, in at least one transmission attempt, a frame over a shared channel to a receiver in another node, the frame being of the type for which a response is expected;
wherein the transmitter is operable to set the timer and flag associated with the node in which the receiver resides if the frame is to be discarded for lack of a response from the receiver; and
wherein the transmitter is operable to determine from the flag if a subsequent frame destined for the receiver is to be discarded without any transmission attempt.