330 likes | 448 Views
Augmenting the Backpressure Collection Protocol to Support Multiple Sinks . Varun Shimoga Prakash, Dr. Omprakash Gnawali Networked Systems Laboratory Dept. of Computer Science University of Houston. Problem Statement.
E N D
Augmenting the Backpressure Collection Protocol to Support Multiple Sinks Varun Shimoga Prakash, Dr. Omprakash Gnawali Networked Systems Laboratory Dept. of Computer Science University of Houston
Problem Statement • Enable the Backpressure Routing technique to route packets to multiple sinks within a network.
Expectations from the Solution • Small Memory Overhead • Packet Delivery Performance • Adherence to conditions imposed by Backpressure Routing.
Possible Solutions • Virtualization of Queue Management • Clustering of Network • Feedback based model.
Virtualization of Queue Management • Each node stores its local backpressure to each of the sink in the network. • Single Queue of Packets • Backpressure values create a virtual queue for each sink. • Backpressure values propagated through beacons or snooping.
Source Node 2 Sink Node 2 Source Node 3 Source Node 1 Source Node 4 Sink Node 3 Sink Node 1
2 3 1 4 { Sink_1: Active }
2 { Sink_2: Active } 3 1 4
2 3 { Sink_1: 1 Sink_2: 1 } 4
2 3 1 4 { Sink_3: Active }
2 3 1 { Sink_3: 1 }
2 { Sink_3: 2 Sink_1: 2 Sink_2: 2 } 3 1
2 3 { Sink_3: 2 Sink_1: 3 Sink_2: 3 } 1
Disadvantages • More the number of sinks, larger the packet header and storage of local backpressure to sinks.
Possible Solutions • Virtualization of Queue Management • Clustering of Network • Feedback based model.
Clustering of Network • Create imaginary clusters in the network where sinks are the centroids. • Controlled Broadcast until packets reach a node in the desired cluster of a sink.
The Network is clustered around each Sink. There is an affiliation of each of the Nodes towards the cluster to which it belongs.
Source Sink
This node has a gradient sloping towards the local sink. Route message through Backpressure routing.
Disadvantages • Controlled Broadcasting does not allow Linear Networks. • Without controlled broadcasting, undesirable redundancy of messages increases.
Possible Solutions • Virtualization of Queue Management • Clustering of Network • Feedback based model.
Feedback Based Model • Sink sends feedback to the last node before it. • Feedback propagate to all nodes in network. • Based on feedback and past performance, nodes choose their next hop.
Source Node 2 Sink Node 2 Source Node 3 Source Node 1 Source Node 4 Sink Node 3 Sink Node 1 Task: Send packets from Source Node 3 to Sink Node 1
2 3 Initially Broadcast the packet 1
2 Broadcast 3 1 Broadcast
2 3 Broadcast 1 Negative Feedback
2 Negative Feedback 3 Broadcast 1 Positive Feedback Sink Node 1
2 Positive Feedback 3 1 Sink 1: Sink Node 1
Sink 1: 2 Positive Feedback 3 1 Sink 1: Sink Node 1
Sink 1: 2 Positive Feedback Sink Node 2 3 1 Sink 1: Sink 2: Sink 3: Sink Node 1
Disadvantages • Convergence of the entire network takes more time in case of mobile sinks. • New weight parameter (feedback) to be considered to calculate weight.