1. Design and Implementation of
Low power Wireless IPv6 Routing
for NanoQplus
Jongsoo Jeong, Jaeseok Kim, and Pyeongsoo Mah

2. 2
Contents
 What is RPL?
 Features
 Objective
 Stack Overflow Issue
 IPv6 Stack for NanoQplus
 Evaluation
 Conclusion

3. 3
What is RPL?
CoAP
 RPL: IPv6 Routing Protocol
for LLNs UDP
 by IETF ROLL WG
 LLNs: IEEE 802.15.4, IEEE RPL
P1901, etc.
 Why RPL?
ICMPv6 IPv6
 Interoperability is essential.
6LoWPAN ND
 Core protocol of ‘Internet
of Things’
6LoWPAN Adaptation Layer
MAC: IEEE 802.15.4

4. 4
Features
 Traffic patterns
 MP2P: forward to a default router Upward (MP2P)
 P2MP: storing or non-storing
 P2P: combination of MP2P and P2MP
 Directed Acyclic Graph
 Distance-Vector (Rank)
 Proactive construction Downward
 Trickle timer
(P2MP)
 Objective Function
 To achieve various goals…
 How to calculate rank values?
 How to construct DAG?
Up+Down (P2P)
 Separated from core function
 User definable and adjustable

5. 5
Objective
 Implementing IPv6 including RPL on top of
NanoQplus.
 NanoQplus
 OS for small wireless sensors and actuators
 Multi-thread
 Up to 15 user threads
 Small stack space for each thread (default: 200 B)
 However, IPv6 network stack is too complex to
be operated in the small stack.

6. 6
Stack Overflow Issue
User
Thread
Stack Peak Stack Usage
Usage
MAC
Max
Stack 6LP
Size
IPv6
UDP
User thread
Time

7. 7
Stack Overflow Issue:
Solution
User
Thread
Stack
Usage
Task Q
Max
Post IP Stack
Size Peak Stack Usage
App
MAC
6LP
IPv6
Task Q User thread
UDP
UDP
Task Time
Pop Queuing
App IP

8. 8
Stack Overflow Issue:
Solution Example #1, #2
RPL
Router
User #3
Thread
Stack
Usage
Max
Posting
Stack
Size Task #3
Posting RPL MAC
Task #2 ICMPv6 6LP
IPv6
IPv6
MAC 6LP ICMPv6
Time
Task #1 Task #2 Task #3
Receiving a frame Receiving a RPL control message Sending a RPL control message

9. 9
Stack overflow safety
Forwarding IP 128
Sending UDP 179
Sending RPL Control 191
UDP ICMPv6 Sending NA 165
Sending NS 181
IPv6 Sending RA 167
Sending RS 177
6LoWPAN Receiving RPL… 109
Receiving NA 108
Receiving NS 108
IEEE 802.15.4
Receiving RA 122
Receiving RS 107
0 50 100 150 200
Maximum Stack Usage

10. 10
IPv6 Stack for NanoQplus
OFn
Applications OF0
RPL Routing
Table
UDP
ICMPv6
6LoWPAN ND Neighbor
Cache
IPv6
6LoWPAN input 6LoWPAN output
NanoMAC (IEEE 802.15.4)

11. 11
Evaluation
B
4 0
6 2
5 3 1
7 8
9

12. 12
Evaluation – Control overhead
250
Number of transmissions per minute
200 Initial state UDP
6LoWPAN-ND
RPL
150
100
Steady state
50
0
0 10 20 30
Time (min)

13. 13
Evaluation – Delivery ratio
100%
90%
80%
70%
99%
92%
Delivery ratio
60%
50%
40%
30%
20%
10%
0%
1025 2049 3073 4097
Rank

14. 14
Conclusion
 RPL Ready in NanoQplus
 Stable IPv6 and RPL operations IPv6 (RPL)
 We implemented the draft-ietf-roll-
rpl-13.
 After becoming RFC document, we will
update it.
 Future Works
 Implementing full fledge RPL with multiple
OFs.
 Supporting CoAP.
 Realizing the Internet of Things.

15. 15
Thank you.
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nos-developers@googlegroups.com