6LoWPAN Ad Hoc On-Demand Distance Vector Routing (LOAD)

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6LoWPAN Ad Hoc On-Demand Distance Vector Routing
(LOAD)
IETF 6LoWPAN WG 66th, Montreal, CA

• Ki-Hyung Kim, S. Daniel Park, G. Montenegro, S.
  Yoo, and N. Kushalnagar

draft-daniel-6lowpan-load-adhoc-routing-02.txt
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Mesh Routing underneath to IPv6 Layer
Application
Application
Application
Transport
Transport
Transport
IPv6
IPv6
IPv6
Adaptation
Adaptation
Adaptation
802.15.4 MAC
802.15.4 MAC
802.15.4 MAC
PHY
PHY
PHY
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LoWPAN Optimizations

• Sub-IP Routing
• Allows efficient header compression, smaller
  route tables
• Use EUI-64 or 16 bit addresses
• Use prot_type field to indicate AODV control
  messages instead of UDP ports
• Utilization of 6lowpan characteristics
• Use the route cost by utilizing the LQI of the
  6LoWPAN PHY
• Allow multiple schemes such as hop counts,
  aggregated LQI values, and minimum LQI value
  along a route
• Hello messages are not used, instead use 802.15.4
  link layer mechanisms such as ACKs, beacon
  responses, overhearing packets, etc
• Use broadcast in the route discovery

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LoWPAN Optimizations II

• Minimize power consumption and complexity
• Do not use the destination sequence number
• Only destination Replies to RREQ by RREP
• Do not use the local repair
• Report back to the originator by RERR upon a link
  break
• Do not maintain the precursorlist
• Send RERR only to the originator of the data
  which caused the link break
• Utilize Efficient RERR reporting
• Reuse existing specs, such as AODV and DYMO, as
  much as possible

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Change Log

• Define the route cost by LQI and weak links
• Hop counts while avoiding weak links
• Several comments
• Default value of weak LQI ? Is there a systematic
  way to determine it
• The necessity of the sequence number
• To prevent a routing loop ? Only destination
  replies to RREQ
• Sequence numbers could also be used as an
  indicator of the freshness of routes ? Sequence
  number could be beneficial for routing ability
• Interaction between QoS metric and distance
  vector routing (Introduction of weak links in
  addition to the hop count)
• Lifetime definition
• Link monitoring (route timeout by timers?) ?
  should consider the expiration policy of routing
  entries based on energy consumption
• Weak link indicator by LQI
• Unidirectional links?
• RERR for low battery and route cost not
  supported should be avoided

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LOAD/DYMO-low Implementations in Progress

• By Pere Salvatella, Wireless Networks Group,
  Technical University of Catalonia (UPC)
•        ------------------------------------------
  ---         Aplication Layer (WebServer,
  TelnetServer)        --------------------------
  -------------------               IP Layer
  (uIP IPv4 Stack TCP/UDP)         
   --------------------------------------------- 
              Routing Layer (DYMO-low, LOAD)    
            -------------------------------------
  --------            6lowpan header (simplified
  version)            ---------------------------
  ------------------           Physical Layer
  (IEEE 802.15.4 radio)          
   ---------------------------------------------

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Prototype Implementation

• http//www.6lowpan.org
• Test bed Implementation
• Segmentation and Reassembly
• Header compression (Format document)
• Gateway between 6lowpan and IPv6 networks
• LOAD/DYMO-low
• Hi-Low

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Overall Architecture of the 6lowpan Testbed
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Protocol stack of 6lowpan router
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Performance Results of LOAD/DYMO-low
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Topology for Testing
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Identifying Weak Links
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Delivery Ratio
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Transmission Delay
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Summary

• Feedback is welcome
• Accept it as a WG item ?