Mechanical Transport of Bits - Part II

Jue Wang and Runhe ZhangEE206A In-class presentationMay 5, 2004

Outline

A Message Ferrying Approach for Data Delivery in Sparse Mobile Ad Hoc Networks (MobiHoc 2004) W. Zhao et al.

Intelligent Fluid Infrastructure for Embedded Networks (MobiSys 2004) A. Kansal et al.

Sparse MANET What is Sparse MANET? What are the challenges for Sparse

MANET? What are the solutions?

Extending transmission range Store – carry – forward Reactive vs Proactive

Related Work Ad Hoc Network Routing:

DSR, DSDV, AODV, GPRS, ZRP, LAR, CEDAR

Ad Hoc Network Routing for Sparse Networks (in detail next slide)

Capacity of Wireless Network Gupta and Kumar Grossglauser and Tse

Topology Control

Related Work:sparse – MANET Infostation: (Goodman et al): High bit rate

connection, geographically distributed, discrete coverage

DataMule: (Shah et al): Static sensor nodes, controllable mobile entities to ‘move’ data

DTN: (Fall et al): no control over the network, nodes stay there, hope for the best

Range extension (Ahmed et al): increase range to overcome the partitions

SWIM (Small and Hass): combines infostation and ad hoc networking architecture (has been presented – Whale)

Sparse – MANET (cont.) Mobility assisted: Proactive, Reactive Epidemic routing: (Vahdat et al) Flooding

(pros: robustness, cons: redundant messages)

Mobile Relay Protocol: (Nain et al) take advantage of node mobility to overcome message delivery

Actively modify trajectories to transmit as soon as possible (hard to have multiple transmission simultaneously)

Message Ferrying (MF) Proposed in this paper Two different types:

Node-Initiated MF (NIMF) Ferries move around the deployed area according to known

routes and communicate with other nodes they meet. With knowledge of ferry routes, nodes periodically move close to a ferry and communicate with the ferry.

Ferry-Initiated MF (FIMF) Ferries move proactively to meet the nodes. When a node

wants to send packets to other nodes, it generates a service request and transmits it to a chosen ferry using long range radio. Upon reception of a service requests, the ferry will adjust its trajectory to meet up with the nodes.

Node-initiated Msg Ferrying

NIMF – node operation

NIMF – Ferry Operation

FIMF – node operation

FIMF – Ferry Operation

Performances NS: Network Simulator 802.11 with 250m communication range 5000x5000m – make sparse 40 nodes, Random Waypoint Models Single Ferry, 15m/s, buffer size 400

message, route: rectangle with (1250,1250), (3750,3750) as diagonal pts.

25 nodes chose to send message every 20 seconds

Performance: Impact of Buffer Size

Performance: Impact of mobility pattern

Performance: FIMF: impact of transmission range

Application

Crisis Driven Battlefield and disaster applications

Geography Driven Wide area sensing and surveillance app.

Cost Driven Service Driven

Conclusion

Sparse network Solution: Proactive vs Reactive Proposal: two schemes for message

ferry Simulation results.

Intelligent Fluid Infrastructure for Embedded Networks

A. Kansal et al. (MobiSys 2004)

What is the paper talk about?

Use of external mobility for improving network performance.

External mobility: Controllable mobility – autonomous mobile router

Network: Sensor Network

Type of Mobility Random Mobility

Increase capacity (Grossglauser and Tse) Application: Whale, Zebranet Problem: Unbounded Delay

Predictable Mobility Chakrabarty et al. (commuter bus model) Problem: Usually mobility pattern is not predictable

Controlled Mobility This paper: External mobility – (for ecological or

habitat researches, no free mobile components, these mobiles may be limited in capacity, maneuverability, etc.)

Another application: DTN

Advantages using controlled mobility – 1

Increased system life time. How? In paper: Reducing the packet sent

(relays – fewer hops) - reducing energy consumption.

More: when you reduce the hop count, you increase the spatial reuse, you also increase the throughput

Advantages using controlled mobility – 1 – Simulation

Advantages using controlled mobility – 2

Data Fidelity The less hop it is, the less probability of

error it occurs. Increase quality of received data,

decrease the number of retransmission.

Advantages using controlled mobility – 3

Advantages using controlled mobility – 3

Reduced latency No mobile router case:

Tideal=T(A,A,B)+T(A,B,Base)+T(B,B,Base) Mobile router case:

Tmobile=D(Base,A)+T(A,A,MR)+D(A,B)+T(B,B,MR)+D(B,Base)

+T({A,B},MR,base)

Advantages using controlled mobility – 4 and others

Sparse and disconnected Networks Reduced communication range Reduced energy consumption

Less hop counts, easier synchro-nization

Security Localization

Processing Platform Stargate xScale 802.11 cards Motes Packbot (60W)

Adaptive Motion Control - Constraint

Energy limitations Terrain constraints Disturbances, noises Environment constraints

Adaptive Motion Control - Objective

Maximize the lifetime of the system Maximize the total amount of data

collected Minimize the data transfer delay Minimize the buffer size Minimize the recharge time? Formulate as Optimization Problem?

Influence of speed of data collection

No effect onpackets/second

Latency Sensitive Data Collection

SCD: Stop to Collectdata Stop at locations

where static nodes are found waiting with data

Latency Sensitive Data Collection ASC: Adaptive Speed Control

Move slower in regions where data collection is moderately poor and stop in regions where data loss is severe.

N1: nodes with low delivery % N2: nodes with high delivery % T: round traversal time Delta = T/2 * 1/(n1+n2/2) SL : encounter of node type N2 ST : encounter of node type N1 TE : current time timer expired Sigma : duration which a timer is reset

Latency Sensitive Data Collection

Latency Sensitive Communication in sparse networks

Propose to use SCD algorithm

Experimental Results – 1

Experimental Results – 2

Experimental Results – 3

Conclusion and Future Works

Controllable Mobility introduced Advantages for using mobile router 2 Strategies for moving 1 mobile

router

Collaboration between mobile routers Scenarios where the sensor nodes are

moving themselves – MANET

Thank you!