MPR-Aware Performance Improvement for Inter-Domain

Routing in MANETs

You Lu, Yenan Lin, Biao Zhou, Mario Gerla

UCLA

Outline

– Introduction & Previous Work

– New features– Dynamic TDMA– MPR-aware Slot Allocation for OLSR– MPR-aware Gateway selection– Simulation Results

– Throughput increased efficiency– Reduced Control Overhead

– Conclusions

Previous Work

– Inter-Domain Routing for MANETs– Group Mobility– One Cluster head per Group– Cluster heads periodically advertise member list– Advertisements propagate via dissemination

LISTA

A

B

LISTB

Previous Work

– TDMA domain is the bottleneck– Inefficient slot usage

– Three categories of TDMA– Static TDMA– Cluster TDMA– Dynamic TDMA

GWS RAODVCSMA2Mbps

OLSRTDMA2Mbps

Our Approach: DTDMA

Slot Allocation for Node 1 contention area

DTDMA with OLSR +MPR

– DTDMA performance much better than STDMA– Same slot reused in different contention areas

– However:– Can we further improve performance?– Yes, if OLSR is used in the TDMA domain– Key idea: assign multiple slots to “popular”

nodes, such as Multipoint Relay Nodes (MPR)

OLSR: Multi Point Relays

New Feature: multiple slots for MPRs

– MPR-aware slot allocation:– MPR nodes get more slots than regular nodes– Motivation: MPRs form the “backbone”– They are the nodes that do most store and

forwarding

– MPRS = MPR Selector, the node that selects that MPR

– The more Selectors, the more popular the MPR

DTDMA : MPR Selectors

Selectors for MPR in node 3

MPR

MPRSMPRS

MPRS

MPRS

More on MPR

MPR- aware Gateway selection- Can further improve performance by selecting as

Gateway a popular MPR Node

- Assign candidate Gateways the WEIGHT:

Performance Evaluation

Simulator: Qualnet 5.0.2–Data traffic: CBR, pkt size 512 byte–Geographic area: 2000m × 2000m–Mobility model: RPGM

– In each domain the Reference Point moves randomly. All nodes in the domain move around the RP

– intra-group speed: 0-5m/s– pause time is 10 seconds

–MAC protocols: CSMA & TDMA–Routing protocols: AODV & OLSR

– Metrics: –Average Receiver Throughput & Normalized Control Overhead

Average Delivered Throughput

The larger the density, the larger the frame for the Contention set => the lower the throughput

Normalized Control Overhead

Conclusion

– Dynamic TDMA +OLSR:– MPR-aware Slot Allocation – MPR-aware Gateway Selection

– We get:– Throughput improvement– Reduced Control Overhead

Thanks

Q & A