1. Multipath Multimedia Transmission in MANETs 1 Marcin Michalak RVS Multipath Multimedia Transmission in MANETs SWAN & NOMAD Marcin Michalak michalak@iam.unibe.ch

2. Multipath Multimedia Transmission in MANETs 2 Marcin Michalak RVS Agenda Basic questions and assumptions Discussed Scenario Related work: – SWAN: Stateless Wireless Ad-hoc Networks – NOMAD: Filters for Mobile IP Role of Layers Network/Application interaction Summary & Goals Questions

3. Multipath Multimedia Transmission in MANETs 3 Marcin Michalak RVS Basic questions how to effectively transfer real-time (multimedia) traffic in mobile ad-hoc networks? how to cater for: –mobility –highly unreliable, shared medium –changing conditions

4. Multipath Multimedia Transmission in MANETs 4 Marcin Michalak RVS Assumptions Practical approach: –changing network as little as possible –some nodes may not be improvement- aware (transparent) –no heavy QoS infrastructure –good quality at low cost

5. Multipath Multimedia Transmission in MANETs 5 Marcin Michalak RVS Discussed scenario streaming live video RTP/UDP transport multipath routing mobile ad-hoc network

6. Multipath Multimedia Transmission in MANETs 6 Marcin Michalak RVS SWAN Stateless Wireless Ad-hoc Networks –intermediate nodes don’t keep per-flow or aggregate state information differentiate real-time and best-effort traffic QoS-capable MAC not needed AIMD algorithm (+  *  - like TCP window) uses feedback information (ECN – explicit congestion notification) http://comet.ctr.columbia.edu/swan/

7. Multipath Multimedia Transmission in MANETs 7 Marcin Michalak RVS SWAN - principles rate control: per-hop MAC delay measurements, performed locally at every node source-based admission control: aggregated real-time traffic info implemented in ns-2 and Linux/AODV

8. Multipath Multimedia Transmission in MANETs 8 Marcin Michalak RVS SWAN operation classifier: differentiates RT and BE packets shaper: –processes BE packets (leaky bucket) –delays them (rate) no admission control in intermediate nodes admission controller: –estimates local bw –sends probe

9. Multipath Multimedia Transmission in MANETs 9 Marcin Michalak RVS SWAN – rate control each node independently regulates best effort traffic packet delay -> shaper (from MAC ACK) local-rate control for best-effort traffic quickly adapts to changes

10. Multipath Multimedia Transmission in MANETs 10 Marcin Michalak RVS SWAN – AIMD rate control algorithm if (n > 0) s= s * (1 – r/100); else s= s+c; if ((s-a) > a * g/100) s=a*(1+g/100); 1+ packets have delays > threshold Procedure called every T seconds: decrease r% increase by c kbps shaping rate – actual rate > g% of actual rate – adjust

11. Multipath Multimedia Transmission in MANETs 11 Marcin Michalak RVS SWAN – admission control task: efficiently estimate local bandwidth availability – listen to medium and measure RT traffic rate (running average) sender-based admission control -> real-time + dynamic regulation of real- time traffic

12. Multipath Multimedia Transmission in MANETs 12 Marcin Michalak RVS SWAN: Admission control procedure S sends a probe packet -> D –estimate bw available –UDP with bottleneck bw field –intermediate nodes update field –no bw reservation admission? of the flow D S UDP bw=? UDP bw=8 UDP bw=8 UDP bw=6

13. Multipath Multimedia Transmission in MANETs 13 Marcin Michalak RVS SWAN – regulation algorithm each node measures continuously utilization of its real-time traffic congestion detected: mark ECN bits  destination destination notifies source reestablishment of the session

14. Multipath Multimedia Transmission in MANETs 14 Marcin Michalak RVS SWAN – network map check bw find route admit? flow regulate bw update bw mark ECN regulate bw drop flow

15. Multipath Multimedia Transmission in MANETs 15 Marcin Michalak RVS SWAN - simulations ns-2 50 nodes, 1500 x 300m 4 voice (32 kbps), 4 video (200kbps) flows video: MPEG-1 stream background: TCP mixture of FTP/Web mobility: –random waypoint model –speed up to 72km/h –node chooses destination, moves, pauses when reached –average 3 hops

16. Multipath Multimedia Transmission in MANETs 16 Marcin Michalak RVS SWAN - results RT Delay below 8 ms (33-77% better) -> 15-20% less TCP traffic Much lower jitter

17. Multipath Multimedia Transmission in MANETs 17 Marcin Michalak RVS SWAN – impact on mobility RT traffic delay much lower and more constant sacrifices TCP traffic Average RT Traffic Delay (ms) Average TCP goodput (kbps)

18. Multipath Multimedia Transmission in MANETs 18 Marcin Michalak RVS SWAN – advantages and results simple & fast effective: –lower delay & jitter for RT traffic –TCP-friendly works with mobility & ad-hoc no complex signalling mechanism Questions & ideas: –how does it behave when implemented partially? –applying multipath – multiflow? –interaction with applications?

19. Multipath Multimedia Transmission in MANETs 19 Marcin Michalak RVS NOMAD: Mobile IP and ad-hoc NOMAD: IST project: Uni Bremen, Telscom, HUT, OTE, T-SYSTEMS and MARAC Filters developed by COMNETS-ikom from University of Bremen Filters for Mobile IP: 2 IETF drafts (v4 and v6) NOMADHOC draft Purpose: –simultaneous use of multiple points of attachment on a single Mobile Device –distribution of multiple flows –distribution of single flow GPRS UMTS

20. Multipath Multimedia Transmission in MANETs 20 Marcin Michalak RVS NOMAD - Modes of operations Multiple Flow DistributionFlow DropSingle Flow Distribution Reg. Filter Weight=0 Index=1 Reg. FC Weight=20 Index=1 Reg. Filter Port=5000 Weight=80 Index=1 Proto=udp & Port=5000 Proto=udp &

21. Multipath Multimedia Transmission in MANETs 21 Marcin Michalak RVS NOMAD Filtering Request

22. Multipath Multimedia Transmission in MANETs 22 Marcin Michalak RVS Filter Modules Types of Filter Modules –DSCP / Flow Label, Traffic Class –Protocol Number –Source Address –Source Network –Source Port Number –Source Port Number Range –Destination Port Number –Destination Port Number Range –Free form, specifies the value of an area anywhere within the packet OR between Filter Module Predicates (src port == 500 || 600) AND between Filter Modules (proto == udp & src port == 500) OR between Filters (src port == 500 || src port == 600)

23. Multipath Multimedia Transmission in MANETs 23 Marcin Michalak RVS NOMADHOC Extensions: AODV Enabling Multiple Paths  F bit on RREQ & RREP Processing Filters  By Source (RREP-ACK, F bit on)  Filter extensions are attached to the RREP-ACK  Destination applies reverse filtering  No changes apply to intermediate nodes draft-nomadhoc-manet-filters-00.txt

24. Multipath Multimedia Transmission in MANETs 24 Marcin Michalak RVS Adaptation of Layers Network Layer Transport Layer Session Layer Application Layer AOMDV + NOMAD UDP m+RTP (multipath) MDC (video) Link Layer802.11 How are layers affected by the new approach?

25. Multipath Multimedia Transmission in MANETs 25 Marcin Michalak RVS Application make it ad-hoc aware: –wireless –mobility –multipath –how to do it? multipath multimedia encoding –Multiple Description Coding (MDC) Network Layer Transport Layer Session Layer Application Layer Link Layer

26. Multipath Multimedia Transmission in MANETs 26 Marcin Michalak RVS Session + Transport meta-RTP/UDP: –resequencing at the receiver react on link changes using RTCP messages more frequent than in wired networks to be continued... Network Layer Transport Layer Session Layer Application Layer Link Layer

27. Multipath Multimedia Transmission in MANETs 27 Marcin Michalak RVS Network IP + AOMDV (or another multipath) NOMAD filters for flows distribution (multi- path/interface) allocation + admission of flows (SWAN): –how to recognize them? –how to interact with application? Network Layer Transport Layer Session Layer Application Layer Link Layer

28. Multipath Multimedia Transmission in MANETs 28 Marcin Michalak RVS Link Layer WLAN 802.11(b) shared medium –no control –adaptation to changing conditions possible ACKs delay can be computed (SWAN) -> available bandwidth Network Layer Transport Layer Session Layer Application Layer Link Layer

29. Multipath Multimedia Transmission in MANETs 29 Marcin Michalak RVS Networkapplication interaction Application Network mark flows indicate flow priority (indicate flow band width) Application Network admit/reject flows congestion info (bandwidth left) Protocol: - transparent for the network - stateless - light

30. Multipath Multimedia Transmission in MANETs 30 Marcin Michalak RVS Flows and distribution 2 flows: –enough distribution –more: too much overhead, hard to find/keep independent 2+ routes flow label to indicate (sub)flows –process ID (16 bits) + flow ID (4 bits) –odd/even flows: different paths (e.g. 2x video + 2x audio) (+ TOS/Traffic class to indicate RT data) 128 bits Source Address 128 bits Destination Address 4 bits Version = 6 8 bits Traffic class 20 bits Flow label 16 bits Payload length 8 bits Next header 8 bits Hop Limit 8 bits Traffic class 20 bits Flow label IPv6 header

31. Multipath Multimedia Transmission in MANETs 31 Marcin Michalak RVS Summary SWAN: –flow admission –flow control –effect: decreases delay & jitter NOMAD filters – flow distribution across: –multipath –multiple interfaces application-network interaction –flow indication (flow label) –congestion indication

32. Multipath Multimedia Transmission in MANETs 32 Marcin Michalak RVS Goals creating complete architecture: –SWAN –NOMAD extensions –user/application/network interaction making it work

33. Multipath Multimedia Transmission in MANETs 33 Marcin Michalak RVS Related Topics load balancing QoS Policy Routing, Active Routing Internet Gateways for ad-hoc

34. Multipath Multimedia Transmission in MANETs 34 Marcin Michalak RVS Questions?