1. Routing and Scheduling for mobile ad hoc networks using an EINR approach Harshit Arora Advisor : Dr. Harlan Russell Mobile ad Hoc Networks A self-configuring network. Does not require any infrastructure. Can have any arbitrary topology at a time. Can operate in a standalone fashion and thus can be helpful in disaster management and military conflicts. EINR model EINR is energy to interference + noise ratio. At a node: Received energy and received interference at the receiver are estimated by using a propagation model. No is the thermal energy of the noise at the receiver. SURE 2007 A B C D Motivation behind the EINR approach Transmission range model. A wants to sent to B, C wants to send to D Using transmission range model Using the EINR model EINR at B EINR at D If EINR at B and D is greater than the EINR threshold (β) then both transmisions are possible. Channel Access protocol 8 time slots. A particular time slot is selected if the following three conditions hold: 1. The time slot is available to both Tx and Rx. 2. Rx satisfies the EINR criterion. 3. All other transmissions continue to maintain acceptable EINR. 1.Transmit data from 1 to 4. 2.Transmit data from 4 to 5. 3.Transmit data from 5 to 3. 4.Transmit data from 2 to 6. Assume that each node has 3 time slots. 4 1 5 3 6 2 Slot 1Slot 2Slot 3 1414 4545 2626 5353 Routing protocol Dijkstra’s algorithm. Links are assigned weight using the ENR (energy to noise ratio) criterion. At any node: Suppose link(4,8) has to be assigned weight. 8 1 2 5 3 7 4 6 No node other than 8 is assumed to transmit. ENR criterion: If ENR > threshold, weight[4,8] =+ve otherwise 0. 1. If threshold = β  Problem!!! 2. Threshold = β*η is a better choice. η is called the interference margin. Tx Rx Routing metrics Min-hop routing: If ENR > β*η link weight = 1 otherwise 0. Disadvantage: If β*η=3.0, for both links wt. = 1. Although link(1,3) is far better than link(2,4) min. hop approach shows no difference. Distance metric approach: If ENR > β*η link weight = otherwise 0 Proposed metric approach: If ENR > β*η link weight = otherwise 0 1 4 2 3 ENR =3.1 ENR =10 Weight =1 Description of Simulation model A randomly generated network topology of N nodes, whose location is randomly decided, is considered in a square region. Links are assigned weights. The network is checked for connectivity. A source and a destination pair is randomly chosen. A route between the source and the destination is obtained. The ‘network diameter’ is the number of links in the longest min-hop route. Slots are allocated to each link in the route. If slot allotment is successful for all links, the route is termed a success. The total number of such successful pairs is determined and is called ‘network capacity’. Simulation Results η=4 η=2 η=1.5 η=1 η=4 η=2 η=1.5 η=1 β=4 N=100 For a fixed β=4, η=2 gives the best nework performance. η=2 N=100 β=0.01 β=1.0 β=4 Proposed approach Min hop approach Distance metric The proposed approach performs better than the min-hop and the distance metric approaches. Background Simulation model Results Conclusion Analysis of different Network topologies show that a low value of β reduces the network dependence on interference. The proposed routing metric protocol gives better network performance. For a fixed area a lower value of β increases the network capacity drastically but average diameter is very small.