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Unformatted text preview: eterministic guarantee in the worst case, in the sense that if any of them is left out then it is not true anymore that the arising backbone is connected for any underlying flat network. MobilityAdaptive Protocols for Managing Large Ad hoc Networks
Properties of Bprotocol
1. 2. 3. Each node in flat network knows only its onehop neighbors. This induces the minimum possible overhead Blink establishment is run at each Bnode only with no knowledge of the surrounding Bnodes. Again, this induces the minimum overhead Every Bnode serves a number of Fnodes each of which is at most threehops away. Bnode selection protocol guarantees that all the Fnodes are served by only one neighboring Bnode 4. 5. There are no two Bnodes that are neighbors in the flat network. This guarantees that Bnodes are evenly distributed in the network Bnode selection is based on the node's current status (weight) MobilityAdaptive Protocols for Managing Large Ad hoc Networks
Properties of Bprotocol
1. 2. The Bnetwork is always connected provided that the underlying flat network is connected Bprotocols takes into account different technologies and mechanisms that can be used to link the Bnodes in the network. Two types of Blinks are provided; namely physical and virtual links. Physical links are used when there is a direct link between Bnodes at most three hops away and virtual links are used when there is a direct link cannot be established MobilityAdaptive Protocols for Managing Large Ad hoc Networks
Simulation Environment A simulator used for an ad hoc network of nodes ranges 100  1000 Nodes can freely move around in a rectangular region (a grid) Node movements are discretized to grid units of 1 meter A node determines its direction randomly by choosing between its current direction (with 75% probability) and uniformly among all other directions (with 25% probability) When a node hits a grid boundary, it bounces back into the region with an angle determined by the incoming direction Fixed transmission range of each node (250 m) and the grid size have been chosen to obtain a good network connectivity Each packet contains the timestamped, node identified weight of the sending node. All packets are sent for the onehop neighbors only MobilityAdaptive Protocols for Managing Large Ad hoc Networks
Simulation Results k is the total number of Fnodes a Bnode can serve at any point in time Three cases: k < n (where n is total number of nodes in network) k<4 k<8 Figure 1: Number of Bnodes (% w.r.t the number of the network nodes) MobilityAdaptive Protocols for Managing Large Ad hoc Networks
Simulation Results k is the total number of Fnodes a Bnode can serve at any point in time Three cases: k < n (where n is total number of nodes in network) k<4 k<8 Figure 2: Number of Blinks (%) when a physical link between any two Bnodes can be established directly. MobilityAdaptive Protocols for Managing Large Ad hoc Networks
Simulation Results k is the total number of Fnodes a Bnode can serve at any point in time Three cases: k < n (where n is total number of nodes in network) k<4 k<8 Figure 3: Number of Blinks (%) when a link between Bnodes is implemented by a physical path with at most three hops away SPAN: An EnergyEfficient Coordination Algorithm for Topology Maintenance in Ad hoc Wireless Networks
[Chen+ 2002] SPAN is a power saving technique for multihop ad hoc networks that reduces energy consumption with the consider...
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 Spring '08
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