Energy and Spatial Reuse Efficient NetworkWide RealTime Data Broadcasting in Mobile Ad Hoc Networks

1
Energy and Spatial Reuse Efficient Network-Wide
Real-TimeData Broadcastingin Mobile Ad Hoc
Networks

• B. Tavli and W. B. Heinzelman
• Julián Urbano
• jurbano_at_vt.edu

2
Overview

• Introduction
• Background
• MH-TRACE
• NB-TRACE
• Simulation
• Conclusions

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Introduction
4
Network-Wide Real-TimeData Broadcasting

• Military networks
• Broadcast
• QoS
• Can not restrict to single-hop
• Energy efficiency, efficient spatial reuse and
  QoS are mandatory
• No architecture proposed so far addressing all
  them
• Network-wide Broadcasting through Time
  Reservation using Adaptive Control for Energy
  efficiency (NB-TRACE)
• Based on MH-TRACE

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Background
6
Energy Dissipation

• Different Categories
• Transmit mode
• Receive mode
• Idle mode
• Carrier sense mode
• Sleep mode

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Energy Dissipation (II)

• How to Achieve it?
• Unnecessary carrier sensing
• Idle energy dissipation
• Overhear irrelevant packets
• Transmit energy dissipation
• Reduce overhead

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Energy Dissipation (III)

• Before
• IEEE 802.11 supports ATIM
• Ad Hoc Traffic Indication Message
• Reduces idle time but doesnt address overhear
• Focused on unicast traffic
• SMAC
• Periodically shuts off radios to reduce idle time
• With low traffic outperforms IEEE 802.11
• TSMAC and RSMAC

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Energy Dissipation (and IV)

• About overhearing
• Information Summarization (IS) packet
• RTS/CTS packets on top of IEEE 802.11
• Power Aware Multiaccess protocol with Signaling
  for Ad Hoc Networks (PAMAS)
• Redundant IS packet? Go sleep!
• Delay, throughput and transmit dissipation
• There is an optimum transmit radio DOP
• Beyond DOP multi-hop outperforms single-hop
• Great for constant transmit range radios

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Efficient Spatial Reuse

• retransmissions required for a packet to be
  received by every node
• Algorithms
• Non-coordinated
• Fully coordinated
• Create a Minimum Connected Dominating Set
• Partially coordinated
• Create a MCDS, almost

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Efficient Spatial Reuse (II)

• Non-coordinated
• Flooding
• With Random Access Delay (RAD) from 0 to TRAD
• Gossiping
• With RAD and probability pGSP

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Efficient Spatial Reuse (III)

• Fully coordinated algorithms
• Based on global info
• NP-problem

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Efficient Spatial Reuse (and IV)

• Partially coordinated algorithms
• Based on local info
• Counter-Based Broadcasting (CBB)
• Count packets until broadcast timer expires
• If received less than NCBB retransmit
• Distance-Based Broadcasting (DBB)
• Based on received power strength
• If closest received is beyond DDBB retransmit

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Quality of Service

• Necessitates
• Low delay
• hops traversed and contention level
• Low jitter
• Deviation from periodicity of packet receptions
• High Packet Delivery Ratio (PDR)
• Drops and collisions
• Parameters
• TDROP 150ms
• Packet Generation period (TPG)
• PDR 95

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Quality of Service (and II)

• Highly related to energy efficiency
• Centralized Control?
• Not practical in Mobile Ad Hoc
• High overhead
• Clustering with Cluster Heads (CH)
• Schedule the channel access
• Some nodes can sleep

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MH-TRACE
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MH-TRACE

• Multi-Hop Time Reservation using Adaptive Control
  for Energy efficiency

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MH-TRACE (and II)

• Gain access through the contention slots
• If gets access fill out the corresponding IS slot
• Transmit in the corresponding data slot
• until it finishes? Starvation?
• Network synchronization through GPS

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NB-TRACE
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Design Principles

• Integrate energy-efficiency in MH-TRACE
• Flooding
• IS (IDnode, IDpacket)
• Go sleep!
• Problems with other algorithms
• MH-TRACE is application-based
• NB-TRACE floods the network and prunes
• Maintain a Control Dominating Set (CDS)

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Overview

• Time Division Multiple Access (TDMA)
• Initially flood to the whole network
• ACK the upstream nodes
• If no ACK in TACK cease rebroadcast
• Algorithm
• Initial Flooding (IFL)
• Pruning (PRN)
• Repair Branch (RPB)
• Create Branch (CRB)
• Activate Branch (ACB)

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Initial Flooding

• Broadcast packets to one-hop neighbors
• Contend channel access and rebroadcast
• Eventually every node has received
• IFL IDD1 for TIFL so every node wakes up

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Pruning

• 3 states for nodes
• Passive
• Active
• Activate Branch (ACB)
• Problem stop ACKing from outermost leaf
• Eventually, only the source node broadcasts
• Solution CHs always rebroadcast
• Maintain the Non-Connected Dominating Set

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Pruning (and II)

• Eventually 1, 3, 5 and 7 go to passive mode
• 0, 2, 4 and 6 make up the broadcast tree
• 5 stops rebroadcast after TACK, 3 stops after
  2TACK, 1 stops after 3TACK
• Problem the nodes are mobile
• Re-flood again? Not efficient

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Repair Branch

• Mobility causes CHs to go out and come in
• New CH stays in startup mode
• Mark the beacon packet
• Every node rebroadcasts it
• Problem broken trees

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Create Branch

• If a node detects an inactive CH in TCRB
• Switch to active and rebroadcast

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Activate Branch

• If a node does not receive for TACB
• Go to ACB mode
• Send ACB packet with pACB
• Into the IS slots in order not to modify MH-TRACE
• If a node receives an ACB packet
• Switch to active and begin relying
• If there is nothing to send, they go to ACB mode
• If an ACB node receives data
• Switch to active and begin relying

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Packet Drop Threshold

• TDROP used throughout the network
• TDROP-SOURCE used at the source node
• TDROP-SOURCETPG

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Simulations
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Overview

• QoS and energy dissipation on
• NB-TRACE
• MH-TRACE with
• Flooding
• IEEE 802.11 and SMAC with
• Flooding
• Gossiping
• CBB
• DBB

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Environment

• Data packets of 110bytes
• Node mobility speed from 0.0 to 5.0m/s
• 2.50.2m/s
• 2.2 0.4m/s
• 1km wide network
• 80 nodes
• Data rate of 32Kbps

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Performance Analysis

• 3B IFL, PRN and RPB
• 4B IFL, PRN, RPB and CPB

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Performance Analysis (II)

• Time
• 81.4 in sleep
• 16.7 in idle
• 2.8 in transmit, receive and carrier sense
• 19.4 of the total energy dissipation
• Energy
• 82.4 packet transmissions
• 7.5 IS transmissions
• 10.1 other control packet transmissions

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Performance Analysis (III)
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Performance Analysis (and IV)
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Varying the Data Rate

• Adjust the superframe size
• Adjust of data slots per frame
• Superframe timeTPG25ms.

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Varying the Data Rate (and II)
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Varying the Node Density

• 1 by 1km network with 48Kbps

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Conclusions
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Overview

• Most of the work to date targeted at deducing
  transmit energy dissipation only
• NB-TRACE also targets receiving, idle, sleep and
  carrier sense dissipation
• According to the 2 (experimental) energy models,
  transmit energy is not as dominant as thought

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Quality of Service

• Satisfies QoS requirements under several
  different scenarios
• Robustness of the broadcast tree
• Maintenance of the NCDS
• Cross-layer design
• Automatic renewal of channel access

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Energy Dissipation

• It is way lower
• Coordinated channel access
• Packet discrimination
• Lower Average Retransmitting Nodes (ARN)

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Delay

• It is larger with small networks
• Restricted channel access
• Maintains a regular delay with bigger networks
• It is much lower with larger networks
• High node density
• High data rates

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Jitter

• Lower to all but MH-TRACE
• Channel access granted by CHs after contend

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Spatial Reuse

• Better than the others
• Robustness of channel access
• Full integration with MAC layer
• IEEEs MAC doesnt prevent excessive collisions
• No data!

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Energy Model

• Energy savings are related to the model
• Some radios do not support sleep mode or the
  dissipation difference is small
• However, NB-TRACE performs well

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Future Work

• Extend TRACE to multicast and unicast
• The blocks are reusable
• CHs can become multicasting group members as they
  always broadcast
• Realistic environments with channel errors
• MH-TRACE is shown to outperform IEEE