MANET: Introduction

Reference: “Mobile Ad hoc Networking (MANET): Routing Protocol Performance Issues and Evaluation Considerations”; S. Corson and J. Macker, RFC 2501, 1999. (rfc2501.htm)

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Introduction• Mobile Ad hoc Networking (MANET)

– To support robust and efficient operation in mobile wireless networks by incorporating routing functionality into mobile nodes

– Such networks are envisioned to have dynamic, sometimes rapidly-changing, random, multihop topologies which are likely composed of relatively bandwidth-constrained wireless links

– Goal: to extend mobility into the realm of autonomous, mobile, wireless domains, where a set of nodes– which may be combined routers and hosts– themselves form the network routing infrastructure in an ad hoc fashion

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Applications

• Industrial and commercial applications involving cooperative mobile data exchange

• “Wearable” computing and communications

• Combined with satellite-based information delivery

– Provide an extremely flexible method for establishing communications for fire/safety/rescue operations or other scenarios requiring rapidly-deployable communications with survivable, efficient dynamic networking

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Characteristics• MANET

– Autonomous system of mobile node

– Nodes are equipped with wireless transmitters and receivers using antennas (omni-directional or highly directional, etc)

• Characteristics– Dynamic topologies

– Bandwidth-constrained variable capacity links

– Energy-constrained operations

– Limited physical security

– The need for scalability

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Routing Issues

• Qualitative properties of routing protocols

– Distributed operation

– Loop-freedom

– Demand-based operation

– Proactive operation

– Security

– “Sleep” period operation

– Unidirectional link support

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Routing Issues (cont)• Quantitative metrics

– End-to-end data throughput and delay

– Route Acquisition Time

– Percentage out-of-order delivery

– EfficiencyAverage number of data bits transmitted/data bit

delivered

Average number of control bits transmitted/data bit delivered

Average number of control and data packets transmitted/data packet delivered

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Routing Issues (cont)

• Networking context– Network size (number of nodes)

– Network connectivity (average number of neighbors of a node)

– Topological rate of change

– Link capacity

– Fraction of unidirectional links

– Traffic patterns

– Mobility patterns

– Fraction and frequency of sleeping node