1. Improving Routing & Network Performances using Quality of Nodes
Navid Nikaein
Sophia-Antipolis.fr

2. Motivation Wireless Mobile Ad Hoc Networks: Goals:
Limited wireless resources  low-capacity
Mobility  time-varying topology
Lack of fixed Infrastructure  fully-distributed
Low-capacity time-varying resources with a fully mobile infrastructure
Goals:
Avoid the cause of link failure at the network layer:
Node mobility
Lack of resources reside in nodes
Trade off between routing overhead & E-2-E delay

3. Outline Basic Idea Quality of nodes  avoid the link failure (goal 1)
Forest construction  reduce overhead (goal 2)
Zone partitioning  improve delay (goal 2)
Results
Conclusion

4. Assumptions Fully symmetric environment Capabilities:
All nodes have identical capabilities
Capabilities:
Transmission range, battery life, processing capacity, buffer capacity
Each node periodically sends a Beacon

5. Network Topology Forest Basic Idea TREE TREE …. TREE ZONE ZONE …. ZONE
BEACON
Forest
Quality of Nodes
TREE TREE …. TREE
BEACON
ZONE ZONE …. ZONE

6. Quality of Nodes V =   s +   b +   p
Power level p  battery lifetime
Buffer level b  available unallocated buffer
Stability level s 
t=t1-t2: period
V =   s +   b +   p

7. Quality of Nodes We classify the quality of nodes into:
High
Medium
Low
Selfish
The quality of nodes is captured using six bits
Two bits per metric to keep low routing overhead, and fast routing decision
If selfish, then ceases to act as a router

8. Forest Construction Preferred neighbor election:
PN(x)={y | V = max ( V ( Nx ) )}, where V can be:
V= Node Degree, OR
V =   s +   b +   p  Quality of Connectivity
If two identical V, then elect the higher ID.
Theorem: connecting each node to its preferred neighbor yield to a forest

9. Zone Partitioning Each tree of the constructed forest forms a zone
Each zone is maintained proactively by exchanging periodical beacon …
Hence, network can be seen as a set of non-overlapping zones

10. Network Topology before & after the Algorithmz2 c h c h d g d g w b w k b k x v z a x v z f a y f z1 y u s t s u i n t e i n e z3

11. Results - Simulation Model
Traffic model:
CBR
512 byte/packet
4 packets/second
Source 10
Performance Metrics:
Packet-delivery-ratio
Acquisition delay
Routing overhead
Movement model:
50 nodes
1500mx300m
0-20 m/s
900 simulated seconds
Pause time=0, 30, 60, 150, 300, 600, 900
10 scenarios for each pause time

12. Packet-Delivery-Ratio

13. Acquisition Delay

14. Routing Overhead (Packets)

15. Routing Overhead (bytes)

16. Conclusion We suggest:
Quality of nodes/connectivity as one of the key parameters in routing and network performances
an architecture that separates logical topology creation from route determination

17. Improving Routing & Network Performances using Quality of Nodes
Thank you

18. Research on Mobile Ad Hoc Networks
Infrastructureless
Wired
Fixed
Mobility
Infrastructured
Wireless