1. Frank H.P. Fitzek
Aalborg University
Network Coding for Mobile Devices and Networks: A BME/AAU/SZTE Success Story

2. User Cooperation in Mobile Cloud

3. Reliable Multicast (1)

4. Reliable Multicast (2) ?

5. Collector‘s Problem P
buying
sharing N
P = N * ( ln (N) )

6. Resource Sharing for Mobile Clouds
App

7. Resource Sharing Display (1)

8. Resource Sharing Display (2)
Taken from the book „Mobile Clouds“, Fitzek/Katz

9. Resource Sharing Microphone
Single microphone ...
... vs. microphone array

10. Huge interest by the „Evil“...
Microsoft IPRs 2008
Apple IPRs 2008

11. … but we cover you …
F.H.P. Fitzek and M. Katz. Cooperation in Wireless Networks: Principles and Applications - Real Egoistic Behavior is to Cooperate! Springer.
F.H.P. Fitzek and M. Katz. Cognitive Wireless Networks: Concepts, Methodologies and Visions Inspiring the Age of Enlightenment of Wireless Communications Springer.

12. Inter flow network coding Intra flow network coding
What is network coding?
Inter flow network coding
XOR type of coding
COPE
CATWOMAN
...
Intra flow network coding
RLNC type of coding
MORE
...
SRC
DST R1 R2 R3 R4
50% 0% b a
a+b

13. Network Coding: The Butterflya
Two packets a and b should be conveyed to two destinations
Capacity per link can handle one packet per time slot
Bottleneck in the middle
Either packet a or b will path the bottleneck

14. Network Coding: The Butterfly
Let‘s try b instead of a
Same old problem a b a b a b b b a b b

15. Network Coding: The Butterflya
a+b
Ahlswede et. al. In 2000
Coding the packet
Other ideas were around
Max-flow min-cut theorem
Ahlswede, Rudolf; N. Cai, Shuo-Yen Robert Li, and Raymond Wai-Ho Yeung (2000). "Network Information Flow". IEEE Transactions on Information Theory, IT-46 46 (4): 1204–1216. 

16. Network Coding: The Butterfly
XOR operation
Bitwise operation
Same bit value results in „0“
Different bit value results in „1“
0101
0011
CODING
0101
XOR 0011
0110
0101
0011
0101
0110
0011
DECODING
0101
XOR 0110
0011
DECODING
0011
XOR 0110
0101
0110
0110
0101
0011
0101
0011

17. Network Coding: The Butterfly
Source: transmitting two information entities
Receiver: receiving two coded information entities

18. Network Coding: The Butterfly

19. Network Coding: The Butterfly

20. Network Coding: The Butterfly++a c b c a c a b b b
b+c ?
a+b a
a+b+c c a
a+c ? c ?
result = (Rank(A)==3) ? "decodable" : "better choice next time”; a c

21. Network Coding: The Butterfly++
What did you send?
What did you send? a c b c a c a b b
What did you send?
What did you send? b
b+c ?
What should we send?
a+b a
a+b+c c a
a+c ? c ?
What did you recveive?
What did you recveive? a c

22. Kirchhoff versus Network Coding
store
and
forward
compute
and
forward
All engineers follow this principle!
Now we are alone ...!

23. Application fields Communication Systems Storage P2P (fixed)
Satellites
Reliable Multicast
Channel Bundling
Wireless Mesh
Mobile Mesh
Storage
Distributed Cloud Storage

24. Random Linear Network Coding
No coding
Binary coding
RLNC coding S S S
a,b
a,b
a,b
a,b
a,b
a,b R R R R R R a
a,b a
a,b,a+b
αa+ βb
α’a+ β‘b D D D
Psucc = 0.5
Psucc =
Psucc = 1

25. S60 Implementation RLNC (2007)
pre-allocated the memory, generated the encoding vectors, so that we only had the raw encoding

26. Current coding speeds in 2012
[kByte/s]
Field size
Generation size
... and in 2007 we had 20 kByte/s for generation size of 50!

27. Current coding speeds in 2012
[kByte/s]
Field size
Generation size
... and in 2007 we had 20 kByte/s for generation size of 50!

28. First implementations
P. Vingelmann, P. Zanaty, F.H.P. Fitzek, and H. Charaf, “Implementation of random linear network coding on opengl-enabled graphics cards,” in European Wireless 2009, Aalborg, Denmark, May 2009.

29. Energy consumption: KODO

30. Energy consumption: KODO

31. What about the dynamic changes?

32. Measurement Setup

33. Testbed

34. What is network coding? XOR type of coding RLNC type of coding
Inter flow network coding
XOR type of coding
COPE
CATWOMAN
...
Intra flow network coding
RLNC type of coding
MORE
...
Inter & Intra flow network coding
Combine the best ...
CORE
...

35. CORE: How does it work?
Identify coding zones/regions

36. CORE: How does it work?
Identify coding zones/regions

37. S2 S1 R D1 D2
Challenge: channel losses
Overhearing is critical for
inter-session

38. CORE Idea: bridge inter- and intra-session network coding
Are we the first to think of combining the two?
No, it is a natural idea
Example: I2NC by Seferoglu et al
But both coding mechanism are treated in different layers and are agnostic to each other.
Intra-session: between TCP and IP
Inter-session: above MAC
What makes us different?
Code structure provided by RLNC (intra-session) used to strengthen inter-session 38

39. CORE

40. CORE

41. CORE

42. CORE

43. CORE

44. CORE

45. CORE

46. CORE

47. CORE

48. CORE

49. CORE

50. CORE

51. CORE

52. CORE

53. CORE

54. CORE

55. Distinctive Features Feedback from R to S1 and S2 Relay can XOR:
Reduces transmissions
May reduce collisions
Relay can XOR:
New packets from both flows
New packet from a flow with recoded packet from the other flow (using packets
Recoded packets from both flows
Receivers (D1 and D2) can:
Use XOR if overhearing was successful to recover their intended coded packet
Store XORed and overheard packets
Perform partial decoding for recovering intended coded packets

56. Throughput vs Offered Load
Symmetric losses
Loss prob = 0

57. Throughput vs Offered Load
Symmetric losses
Loss prob = 0.3

58. Throughput vs Offered Load
Symmetric losses
Loss prob = 0.5

59. Throughput vs Offered Load
Symmetric losses
Loss prob = 0.8

60. Demonstrator On youtube: http://www.youtube.com/watch?v=mKiHKtZRFVU
(Search for “CORE Network Coding”)

61. Cooperation Focus
Network coding sample application filed: FuturICT.hu (BME/AAU/SZTE)
Related topics:
Mobile cross-platform design patterns
Mobile P2P middleware design patterns and algorithms
Mobile cloud
Monitoring mobile and sensor networks
Model-driven application development for multiple mobile platforms

62. Cooperation Outcome (without having 1 Euro received)
Combined AAU/BME PhD program
1 completed
4 ongoing
Three book projects and one project with Wiley ongoing
Best Paper award at CCNC 2011 on network coding with iOS
StartUps in Berlin and Aalborg
Combined PhD courses (with Professor Medard from MIT)
Publications
1 edited book
1 book chapter (several on the own book projects)
2 journal (one submitted)
12 conference