The document discusses the need for a new communication stack called the KSN Radio Stack to enable reliable wireless communication for data-intensive applications in sensor networks. The current Sun Stack is unreliable for transmitting large messages over multiple hops. The KSN Radio Stack aims to provide reliable delivery of large messages through mechanisms like the Single Hop Protocol (SHP) and by allowing for multiple communication stacks to run simultaneously on a single node. It also provides examples of how additional layers can extend the stack's capabilities, such as an AODV routing layer for multi-hop communication.

1. Markus Bestehorn Stephan Kessler
Andreas Leppert Sven Meisinger
KSN Radio Stack:
pp g
KSN Radio Stack:
Reliable Wireless Communication for Data-
intensive Applications in Sensor Networksintensive Applications in Sensor Networks
Sun SPOT Symposium 2009
London
www.kit.edu

2. Data-Intensive Application in WSN?
Wireless Sensor Network (WSN)
Large number of battery powered devices
Introduction
Data-Intensive
S St k
g y p
energy is valuable!
Exchanging data using wireless communication
User can access network through base station Sun SPOT
Sun Stack
KSN Radio Stack
Design Targets
SHP User can access network through base station
Countless Applications
Medical Care, Environment Monitoring, Object Tracking…
Su S O
SHP
Routing
Other Layers
Demo
What is data-intensive application in WSN?
2 variations:
Nodes generate Data
Comparison
KSN
Team g
Data must be transported to user / base station
Amount of data accumulates on the way
Base station has to distribute data to the whole network
Acitivities
Research
Q&A Base station has to distribute data to the whole network
2 examples follow
Slide 2Markus Bestehorn

3. Example 1: Data Gathering
Data Gathering Applications
A large number of nodes
Introduction
Data-Intensive
S St k
g
Generating / Measuring data (continously)
Sending measured data back to base station
Sun Stack
KSN Radio Stack
Design Targets
SHPSHP
Routing
Other Layers
Demo
More Sensor Nodes
Base
Comparison
KSN
Team
D it C i /A ti
Base
StationAcitivities
Research
Q&A
Despite Compression/Aggregation:
Messages of several KB have to transmitted reliably
Large part of result is lost if 1 message is lost!
Slide 3Markus Bestehorn

4. Example 2: Over-the-Air Deployment
Testbeds
Evaluate your software
Introduction
Data-Intensive
S St k
y
Test and debug software
Sun Stack
KSN Radio Stack
Design Targets
SHP Problem: Testing-Cycle very cumbersome
1. Connect SPOT to USB
2. Put SPOTs into position
SHP
Routing
Other Layers
Demo u S O s o pos o
3. Start testing / evaluation
1. Errors in software?
2 Find error fix code
Comparison
KSN
Team 2. Find error, fix code
4. Collect SPOTs and start with step 1
Solution:
Acitivities
Research
Q&A
Fixed infrastructure connected to nodes
Not possible/feasible or all deployments
Distribute software over-the-air (OTA)
Slide 4
( )
Markus Bestehorn

5. Example 2: Over-the-air Deployment (cont‘d)
Requires large files / messages to be transmitted
Query Processor suite file ~500 KB
Introduction
Data-Intensive
S St k
Q y
Libraries ~700 KB
„Large“ Number of Hops
I b d f 30 SPOT 9 H
Sun Stack
KSN Radio Stack
Design Targets
SHP In our testbed of 30 SPOTs max. 9 Hops
Any testbed requires transmission of large
SHP
Routing
Other Layers
Demo Any testbed requires transmission of large
messages over multiple hopsComparison
KSN
Team
Acitivities
Research
Q&A
Slide 5Markus Bestehorn

6. Requirements of data-intensive Applications
Communication software (stack) must
Deliver messages reliably
Introduction
Data-Intensive
S St k
g y
Cope with relatively large messages
Multiple Hops between sender and receiver node
P ti l l h d i t k
Sun Stack
KSN Radio Stack
Design Targets
SHP Particularly hard in sensor networks
Expect nodes to fail during transmission
React to topology changes due to external influences, e.g.,
SHP
Routing
Other Layers
Demo p gy g g
Weather
Closing/Opening of doors
Comparison
KSN
Team
SPOTs are shipped with a communication stack
Why not use this stack?
Acitivities
Research
Q&A
Slide 6Markus Bestehorn

7. Testing the Sun Stack (1)
Setup for evaluation
2-5 nodes in a line, i.e., 1-4 hops
Introduction
Data-Intensive
S St k
, , p
1 specified node sends a message of varying size
RadioStream was used
After sending node computes a hash value of the message
Sun Stack
KSN Radio Stack
Design Targets
SHP After sending, node computes a hash value of the message
1 specified node receives message
When receiving completes, receiver computes hash value over
received message
SHP
Routing
Other Layers
Demo received message
Transmission successful, if both hash values are equal
Code can be obtained from our homepage:
htt // i d i k l h d /KSN
Comparison
KSN
Team
http://www.ipd.uni-karlsruhe.de/KSNAcitivities
Research
Q&A
Sender Receiver
Slide 7Markus Bestehorn
Sender Receiver

8. Testing the Sun Stack (2)
Evaluation was conducted with the „Blue“ release (current)Introduction
Data-Intensive
S St kSun Stack
KSN Radio Stack
Design Targets
SHPSHP
Routing
Other Layers
Demo
Comparison
KSN
Team
Acitivities
Research
Q&A
Slide 8Markus Bestehorn

9. Motivation for a new stack
Sun stack is reliable and fast for small messages
Almost no errors for message sizes below 1KB
Introduction
Data-Intensive
S St k
g
Unreliable for large messages or high number of hops
Main reason: Design Goals for the Sun Stack
L P
Sun Stack
KSN Radio Stack
Design Targets
SHP Low Power
Efficient usage of low bandwidth available
Design not aimed at „data-intensive“ applications
SHP
Routing
Other Layers
Demo g „ pp
Messages are transmitted reliably
1 h
Comparison
KSN
Team
over 1 hop
802.15.4 layer works
Errors must occur above
Acitivities
Research
Q&A
Design new stack above MAC
Slide 9Markus Bestehorn

10. Agenda
Motivation: Why do we need another stack?
What does „data-intensive“ in sensor networks mean
Introduction
Data-Intensive
S St k
„
Demo and reliability evaluation data
KSN Radio Stack
D i & ddi i l f
Sun Stack
KSN Radio Stack
Design Targets
SHP Design targets & additional features
The core of the KSN Stack
Optional KSN stack layers
SHP
Routing
Other Layers
Demo p y
Possibilities for Optimization / Improvements
Reliability evaluation and Demo of the KSN stack
Comparison: Sun Stack vs KSN Stack
Comparison
KSN
Team
Comparison: Sun Stack vs. KSN Stack
The KSN Team
Projects
Acitivities
Research
Q&A
Research Agenda
Slide 10Markus Bestehorn

11. Design Targets - Reliability
Transmission of large messages over multiple hops must
work reliably
Introduction
Data-Intensive
S St k
y
Problems encountered during transmission must be fixed inside
the communication stack if possible
Handling of errors should not be mixed with application code
Sun Stack
KSN Radio Stack
Design
SHP Handling of errors should not be mixed with application code
Expect nodes to fail during transmission
External influences change communication behaviour of nodes
Weather
SHP
Routing
Other Layers
Demo
Weather
Closing doors
Sender must know if transmission failed on intermediate
Comparison
KSN
Team
nodes End-to-End ACKAcitivities
Research
Q&A
Sender Receiver
ACK
Slide 11Markus Bestehorn

12. Design Targets - Extendability
Different applications have different demands
Run Multiple Stacks parallely on one SPOT
Introduction
Data-Intensive
S St k
p p y
Adding / implementing new layers
Network Management might require another stack than Query
Processing
Sun Stack
KSN Radio Stack
Design
SHP Processing
Stack with less complex interfaces for student experiments,
more sophisticated stack to gather the result of their
experiments
SHP
Routing
Other Layers
Demo experiments
Comparison
KSN
Team
Acitivities
Research
Q&A
Slide 12Markus Bestehorn

13. Further Design Targets
Compatibility with 802.15.4
Interface-Compatibility to Sun Stack
Introduction
Data-Intensive
S St k Interface Compatibility to Sun Stack
Users have written applications using the Sun Stack
Migrating to our stack should not require rewriting the
application
Sun Stack
KSN Radio Stack
Design
SHP application
Link-Quality-awareness
Probability for failures increases, as link quality decreases
SHP
Routing
Other Layers
Demo
Communication hardware on SPOTs allows estimations about
link quality
Example: Quality-Aware Routing Layer
Comparison
KSN
Team p y g y
Acitivities
Research
Q&A
Slide 13Markus Bestehorn

14. Optimization is not a Design Target
Communication stacks for sensor nodes are usually
optimized regarding energy usage
Introduction
Data-Intensive
S St k
p g g gy g
Nodes are usually battery-powered
Reliability is the most important step towards efficiency
U t k t i i f ti
Sun Stack
KSN Radio Stack
Design
SHP Users query a sensor network to gain information
demand for information has to be satisfied (efficiently)
If failures prevent delivery of information
SHP
Routing
Other Layers
Demo
Energy used to acquire information until failure occured is wasted!
Users might retry Failure likely to occur again more waste!
Optimization is the step after functionality is ensured
Comparison
KSN
Team p p y
“We should forget about small efficiencies, say about 97% of
th ti t ti i ti i th t f ll il ”
Acitivities
Research
Q&A
the time: premature optimization is the root of all evil.”
(Donald Knuth)
Slide 14Markus Bestehorn

15. Foundation for Reliable Communication
Basic Operation of 802.15.4:
Sending a packet of 127 byte
Introduction
Data-Intensive
S St k
g p y
Receiver is a node within the radio range of the sender
Two variants of the Basic Operation:
B d R i dd i bl k“
Sun Stack
KSN Radio Stack
Design
SHP Broadcast: Receiver address is „blank“
No acknowledgement
Unicast: Receiver address identifies node
SHP
Routing
Other Layers
Demo
If transmission of 127 byte was successful, acknowledgement is
sent
If there was a failure, no acknowledgement is received and a
i i
Comparison
KSN
Team
timeout expires.
Reliable communication is based on this basic operation
First Step:
Acitivities
Research
Q&A First Step:
Design communication protocol for messages larger than 127
byte
Slide 15Markus Bestehorn

16. SHP – Single Hop Protocol
Single Hop Protocol (SHP) Layer provides interface for
Unicast of messages of arbitrary size
Introduction
Data-Intensive
S St k
g y
Broadcast of messages of arbitrary size
Preparation for sending (unicast or broadcast)
L t M M h i f b b t
M
Sun Stack
KSN Radio Stack
Design
SHP Let Message M have a size of b bytes
Decompose M into f fragments
Assign a sequence number s={1…p}
41 32
SHP
Routing
Other Layers
Demo g p
to each fragment
Compute checksum C from M
Sending process for unicast and broadcast different
C
Comparison
KSN
Team Sending process for unicast and broadcast different
starting with broadcast
Acitivities
Research
Q&A
Slide 16Markus Bestehorn

17. Single Hop Protocol - Broadcast
Two types of packets
BroadcastData: Contains fragments
Introduction
Data-Intensive
S St k
g
of 104 Byte, used for first f-1 fragments
BroadcastEnd: Contains last fragment
with sequence number s=f
Sun Stack
KSN Radio Stack
Design
SHP
with sequence number s f
Possible failures:
Unexpected sequence number
SHP
Routing
Other Layers
Demo
Timeout while waiting for next/last
fragment
Limitations (current implementation)
Comparison
KSN
Team ( p )
Sequence Number is 16-bit long
max. Broadcast ~ 6 MB
sufficient for SPOTs
Acitivities
Research
Q&A
Slide 17Markus Bestehorn

18. SHP – Possible Broadcast Improvement
Problem: Broadcast still inherently unreliable
Sender broadcasts f fragments to surrounding nodes
Introduction
Data-Intensive
S St k
f g g
Some receivers only receive k<f fragments
Receiver has spent energy, but message is incomplete
receiver discards all received fragments energy wasted!
Sun Stack
KSN Radio Stack
Design
SHP receiver discards all received fragments, energy wasted!
Possible improvement (not yet implemented):
Each receiver uses sequence numbers to determine, which k
SHP
Routing
Other Layers
Demo
fragments are missing
If k is sufficiently small compared to f, ask sender to resend
missing fragments with unicast
Comparison
KSN
Team
Open questions:
Caching mechanisms for broadcast messages on sender
What is sufficiently small“?
Acitivities
Research
Q&A
What is „sufficiently small ?
Slide 18Markus Bestehorn

19. Single Hop Protocol - Unicast
SHP - Unicast Protocol
1. Send UnicastRequest to receiver
Introduction
Data-Intensive
S St k
q
Contains Checksum C
Size b of Message M in bytes
receiver can abort transfer
Sun Stack
KSN Radio Stack
Design
SHP
2. Send f fragments to receiver
Receiver has to acknowledge each
fragment
SHP
Routing
Other Layers
Demo g
Unacknowledged fragments are
retransmitted after a timeout
3. Receiver checks if data is not
Comparison
KSN
Team
disrupted using checksum CAcitivities
Research
Q&A
Slide 19Markus Bestehorn

20. SHP – Unicast Improvements
Evaluation has shown:
Data rates with Sun stack higher than with KSN stack
Introduction
Data-Intensive
S St k
g
Comparable only for small messages due to reliability
Reason for lower data rate:
A k l d f h f
Sun Stack
KSN Radio Stack
Design
SHP Acknowledgment for each fragment
congestion
Less payload due to larger sequence numbers
SHP
Routing
Other Layers
Demo
Ideas for improvements: „TCP/IP-like ACK“
Aggregate ackowledgements and send 1 packet to
acknowledge several received fragments
Comparison
KSN
Team acknowledge several received fragments
Increase number of packets between ackowledgements
depending on link quality
Acitivities
Research
Q&A
Slide 20Markus Bestehorn

21. Summary Single Hop Protocol
SHP offers reliable delivery to 1-hop neighbors
Broadcast
Introduction
Data-Intensive
S St k
Unicast
Message size
B d d 6 MB f b d SPOT h
Sun Stack
KSN Radio Stack
Design
SHP Bounded to 6 MB for broadcast
Theoretically unbounded for unicast
VM defines boundaries for max. array length
SPOT has
512KB of
RAM
SHP
Routing
Other Layers
Demo
Layer still not fine-tuned
large room for improvements!
Comparison
KSN
Team
Design targets so far?
Extendability not yet
Acitivities
Research
Q&A
802.15.4 compatiblity done
Reliability only 1 hop
Slide 21Markus Bestehorn

22. Extendability – Multiple Stacks, 1 SPOT
All communication is based on reliable 1-hop communication
SHP usable as a foundation
Introduction
Data-Intensive
S St k
Idea to allow multiple stacks
Each Stack is assigned a globally unique ID
we used a simple byte value
Sun Stack
KSN Radio Stack
Design
SHP we used a simple byte value
max. 256 different stacks
Special byte indicates stack ID
E h d Di t h t
SHP
Routing
Other Layers
Demo
Each node uses a Dispatcher to
Pass incoming data to correct stack depending on stack ID
Pass outgoing data to SHP Layer
Comparison
KSN
Team
SHP Dispatcher has 4 functions
Register / unregister new
stack
Acitivities
Research
Q&A
Broadcast / unicast data
using SHP
Slide 22Markus Bestehorn

23. Extendability – More Stack-Layers
All new layers must implement LayerInterface
Methods for broadcast / unicast of data from upper layers
Introduction
Data-Intensive
S St k
pp y
Method, which takes incoming data from lower layers or the
SHP Level Dispatcher
Abstract Layer implementation is provided with our software
Sun Stack
KSN Radio Stack
Design
SHP Abstract Layer implementation is provided with our software
New Layers can be implemented with very few lines of code
Example of a AODV Routing Layer follows now
SHP
Routing
Other Layers
Demo
Comparison
KSN
Team
Acitivities
Research
Q&A
Slide 23Markus Bestehorn

24. Example Layer – Multi-Hop Routing
Up to this point, only 1-hop communication covered
Example for a new Layer: Routing Layer
Introduction
Data-Intensive
S St k
p y g y
Used Routing Mechanism:
Ad-Hoc On Demand Distance Vector Routing (AODV) [2]
Sun Stack
KSN Radio Stack
Design
SHP
Sun Stack also includes AODV implementation, but
No (working) End-to-End ACKs for Multi-Hop Unicasts
SHP
Routing
Other Layers
Demo ( g) p
Only 1 entry per Receiver no backup routes
Both problems affect reliability
Comparison
KSN
Team
will be addressed in the
following
Acitivities
Research
Q&A
Slide 24Markus Bestehorn

25. AODV Routing Mechanism
Basics of AODV:
Sender S wants to send message to Receiver R
Introduction
Data-Intensive
S St k
g
S broadcasts Route Request (RREQ)
Nodes receiving RREQs rebroadcast if
RREQ has not been broadcasted before
Sun Stack
KSN Radio Stack
Design
SHP RREQ has not been broadcasted before
Node already has a route to R stored in routing table
Receiver R receives the RREQ
Route Report (RREP) is sent back to S
SHP
Routing
Other Layers
Demo
Route Report (RREP) is sent back to S
Message is sent through shortest / fastest-available route
Comparison
KSN
Team
RREQRREQAcitivities
Research
Q&A
RREQRREQ RREQ RREPRREQ
ACKACKACK
Slide 25Markus Bestehorn
Sender Receiver

26. AODV – Routing Table Format
Routing Table without backup entries
1 entry for each receiver R
Introduction
Data-Intensive
S St k
y
If transfer fails, new RREQ is broadcast by sender S
Problem: RREQ very small message (1 packet)
might be transmitted reliably but larger messages fail
Sun Stack
KSN Radio Stack
Design
SHP might be transmitted reliably, but larger messages fail
same Route will be returned
transfer might fail again for larger message energy
wasted!
SHP
Routing
Other Layers
Demo wasted!
Solution:
Several entries for 1 receiver R
Comparison
KSN
Team
Use depth-first search to transmit
larger message to R
Can be adapted to use
Acitivities
Research
Q&A
quality information!
Slide 26Markus Bestehorn

27. AODV – End-to-End ACK
SHP sends ACK if message is transmitted correctly
Problem:
Introduction
Data-Intensive
S St k Problem:
Intermediate node fails while sending
Intermediate node has sent ACK already, but message is lost!
Sun Stack
KSN Radio Stack
Design
SHP Solution: Receiver sends End-to-End ACK to sender
Sender waits for End-to-End ACK
Length of timeout determined using hop count of routing table
SHP
Routing
Other Layers
Demo e g o eou de e ed us g op cou o ou g ab e
SHP-ACK
Comparison
KSN
Team
Design targets so far?
Sender ReceiverEnd-to-End ACK
Acitivities
Research
Q&A g g
Extendability done
802.15.4 compatiblity done
Reliability done
Slide 27
Reliability done
Markus Bestehorn

28. Other Layers
Reducing Data Size
Compression layer
Introduction
Data-Intensive
S St k
p y
Can be used with abitrary compression algorithm
We use a modified ZIP algorithm
Should be used above routing layer
Sun Stack
KSN Radio Stack
Design
SHP Should be used above routing layer
Avoids decompression on every hop
Protocol Dispatcher
SHP
Routing
Other Layers
Demo
Applications can use different protocols
on top of single stack!
Examples:
Comparison
KSN
Team p
PC-like with ports
LowPan
Acitivities
Research
Q&A
Slide 28Markus Bestehorn

29. KSN Radio Stack Demo
Message Size: 50 KB
Tested up to 1 MB with more than 10 hops
Introduction
Data-Intensive
S St k
p p
4 Hops
Output Power -30
Sun Stack
KSN Radio Stack
Design
SHP Difference to demo before
„Simulation“ of node failures by removing/exchanging nodes
Simulated „failure“ will cause delay
SHP
Routing
Other Layers
Demo S u a ed „ a u e cause de ay
Message delivered despite topology changes
„Application“ has not been changed
Comparison
KSN
Team
Acitivities
Research
Q&A
Sender Receiver
Slide 29Markus Bestehorn

30. Comparison of both Stacks
Sun Stack
Very fast and efficient for small messages
Introduction
Data-Intensive
S St k
y g
use for experiments where „every second counts“
Unreliable if
Messages become large
Sun Stack
KSN Radio Stack
Design
SHP Messages become large
Messages must be transmitted over a large number of hops
Other transmissions from other SPOTs run parallely
Was not shown here
SHP
Routing
Other Layers
Demo Was not shown here
IPv6 compatible
KSN Radio Stack
Comparison
KSN
Team
Reliable for large message sizes and large number of hops
Up to 1 MB
And 15 hops tested without losing messages
Acitivities
Research
Q&A
More overhead slower
Use for experiments where „counting bytes“ is sufficient
Currently not IPv6 compatible
Slide 30
Currently not IPv6 compatible
Markus Bestehorn

31. Agenda
Motivation: Why do we need another stack?
What does „data-intensive“ in sensor networks mean
Introduction
Data-Intensive
S St k
„
Demo and reliability evaluation data
KSN Radio Stack
D i & ddi i l f
Sun Stack
KSN Radio Stack
Design
SHP Design targets & additional features
The core of the KSN Stack
Optional KSN stack layers
SHP
Routing
Other Layers
Demo p y
Possibilities for Optimization / Improvements
Reliability evaluation and Demo of the KSN stack
Comparison: Sun Stack vs KSN Stack
Comparison
KSN
Team
Comparison: Sun Stack vs. KSN Stack
The KSN Team
Projects
Acitivities
Research
Q&A
Research Agenda
Slide 31Markus Bestehorn

32. Who is who @ KSN?
Stephan Kessler
Student Assistant
Introduction
Data-Intensive
S St k
KSN Serialization & Stack
Sun Stack
KSN Radio Stack
Design
SHP Andreas Leppert
Student Assistant
KSN Stack, Query Dissemination
SHP
Routing
Other Layers
Demo S S ac , Que y sse a o
Sven Meisinger
Comparison
KSN
Team
Student Assistant
KSN Serialization, Simulator
Acitivities
Research
Q&A
Markus Bestehorn
PhD student
Slide 32
Project Head
Markus Bestehorn

33. KSN – Other Projects
Management Application
Controlling large testbeds of SPOTs
Introduction
Data-Intensive
S St k
g g
Software deployment uses KSN Stack
Support for experiments, e.g., collect data
S i li ti f SPOT
Sun Stack
KSN Radio Stack
Design
SHP Serialization for SPOTs
Serialization used in JDK to store/send objects
not supported by Squawk VM
SHP
Routing
Other Layers
Demo
Pure Java serialization
Testbed
30+ nodes deployed at the IPD
Comparison
KSN
Team 30+ nodes deployed at the IPD
Real network for experiments
Acitivities
Research
Q&A
Many more…
Homepage: www.ipd.uni-karlsruhe.de/KSN
Slide 33Markus Bestehorn

34. KSN – Sensor Databases
Research Topic: Sensor Databases
Problem: Every new application for WSN requires complete
Introduction
Data-Intensive
S St k
y pp q p
development process
Design & implement new hardware
Design & implement new software
Sun Stack
KSN Radio Stack
Design
SHP
Design & implement new software
very costly
Idea: Provide database-like interface for WSN
Ad t U ft f WSN li ti l
SHP
Routing
Other Layers
Demo
Advantage: Use same software for new WSN application, only
change query
Example: SPOT 1 SPOT 2
Comparison
KSN
Team
Measurement stored distributedly in tables
Temp: 25.3°C
Hum.: 78%
Light: 124
Temp: 23.4°C
Hum.: 77%
Light: 120
Acitivities
Research
Q&A
Measurement stored distributedly in tables
Use SQL to query data, e.g.,
SELECT nodeID, temp FROM Sensors
Slide 34
Size of result depends on query data-intensive!
Markus Bestehorn

35. KSN – Current Research Topics
Approximate Query Processing
Reduce result quality to save energy
Introduction
Data-Intensive
S St k
q y gy
Different quality parameters possible
Precision of result
Security
Sun Stack
KSN Radio Stack
Design
SHP Security
Consistency
Query Distribution
SHP
Routing
Other Layers
Demo
Broadcast of query very energy consuming
Use structure of query to choose distribution strategy
try to reach all relevant nodes, but not all nodes!
Comparison
KSN
Team
Spatio-Temporal query processing in WSN
Moving object DBs provide operators to query object movement
Only for historical data stored in a DB server
Acitivities
Research
Q&A Only for historical data stored in a DB server
Idea: Try to provide these operators for object tracking in WSN
Slide 35Markus Bestehorn

36. Thank you for your attention!
Questions?
Introduction
Data-Intensive
S St k Questions?Sun Stack
KSN Radio Stack
Design
SHP
References
SHP
Routing
Other Layers
Demo
No. Reference
[1] MICA2 Sensor Node, http://www.xbow.com/
P ki R Ad h d d di t t ti M bil C ti
Comparison
KSN
Team
[2]
Perkins, Royer: Ad-hoc on-demand distance vector routing; Mobile Computing
Systems and Applications, 1999
Acitivities
Research
Q&A
Slide 36Markus Bestehorn