Qo S Routing In Ad Hoc Networks


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  • Qo S Routing In Ad Hoc Networks

    1. 1. QoS Routing in Ad Hoc Networks --Literature Survey Presented by: Li Cheng Supervisor: Prof. Gregor v. Bochmann
    2. 2. Outline <ul><li>QoS routing overview: targets and challenges </li></ul><ul><li>Classification of QoS routing protocols </li></ul><ul><li>Typical QoS routing protocols </li></ul><ul><li>Conclusion and Open Issues </li></ul>Video frame without QoS Support Video frame with QoS Support
    3. 3. Features of MANET <ul><li>Mobile Ad-hoc Network </li></ul><ul><li>Definition: a self-configuring network of mobile routers (and associated hosts) connected by wireless links—the union of which form an arbitrary topology ( www.wikipedia.org ) </li></ul><ul><li>Features </li></ul><ul><ul><li>Dynamic and frequently changed topology </li></ul></ul><ul><ul><li>Self-organizing </li></ul></ul><ul><ul><li>Nodes behaving as routers </li></ul></ul><ul><ul><li>Minimal configuration and quick deployment </li></ul></ul><ul><ul><li>Limited resources </li></ul></ul>
    4. 4. Ad Hoc vs. Cellular Networks <ul><li>Multi-hop route vs. One-hop route </li></ul><ul><ul><li>In an Ad Hoc network, every nodes has to behave as a router </li></ul></ul><ul><li>Self-administration vs. Centralized Administration </li></ul><ul><ul><li>Ad hoc networks are self-creating , self-organizing , and self-administering </li></ul></ul>PSTN MSC OMC AC VLR BSC BSC BSC BTS BTS BTS MS Cellular wireless network Ad Hoc wireless network GMSC HLR MS
    5. 5. Target of QoS Routing <ul><li>To find a feasible path between source and destination, which </li></ul><ul><ul><li>satisfies the QoS requirements for each admitted connection and </li></ul></ul><ul><ul><li>Optimizes the use of network resources </li></ul></ul>A B C D E F G <2,4> <3,3> <4,5> Tuple: <BW,D> QoS requirement: BW≥4 <2,2> <5,4> <4,4> <5,3> <4,2> <3,4> Shortest path QoS Satisfying path
    6. 6. Challenges of QoS Routing in Ad Hoc Networks <ul><li>Dynamic varying network topology </li></ul><ul><li>Imprecise state information </li></ul><ul><li>Scare resources </li></ul><ul><li>Absence of communication infrastructure </li></ul><ul><li>Lack of centralized control </li></ul><ul><li>Power limitations </li></ul><ul><li>Heterogeneous nodes and networks </li></ul><ul><li>Error-prone shared radio channel </li></ul><ul><li>Hidden terminal problem </li></ul><ul><li>Insecure medium </li></ul><ul><li>Other layers </li></ul>
    7. 7. Criteria of QoS Routing Classification <ul><li>Routing information update mechanism </li></ul><ul><ul><li>Proactive/table-driven: QOLSR, EAR </li></ul></ul><ul><ul><li>Reactive/On-demand: QoSAODV, PLBQR, TBP </li></ul></ul><ul><ul><li>Hybrid: CEDAR </li></ul></ul><ul><li>Use of information for routing </li></ul><ul><ul><li>Information of past history: QOLSR, QoSAODV, TBP </li></ul></ul><ul><ul><li>Prediction: PLBQR </li></ul></ul><ul><li>State maintenance </li></ul><ul><ul><li>Local: PLBQR, CEDAR </li></ul></ul><ul><ul><li>Global: TDMA_AODV, TBP </li></ul></ul><ul><li>Routing topology </li></ul><ul><ul><li>Flat: QOLSR, QoSAODV, PLBQR, TBP </li></ul></ul><ul><ul><li>Hierarchical: CEDAR </li></ul></ul><ul><li>Interaction with MAC layers </li></ul><ul><ul><li>Independent: PLBQR, QoSAODV, TBP </li></ul></ul><ul><ul><li>Dependent: CEDAR, PAR </li></ul></ul><ul><li>Number of Path Discovered </li></ul><ul><ul><li>Single path: QoSAODV , CEDAR, PLBQR </li></ul></ul><ul><ul><li>Multiple paths: TDMA_AODV, TBP </li></ul></ul><ul><li>Utilization of Specific Resources </li></ul><ul><ul><li>Power aware routing: PAR, EAR </li></ul></ul><ul><ul><li>Geographical information assisted routing: PLBQR </li></ul></ul>
    8. 8. Typical Routing Mechanism <ul><li>Proactive routing: QOLSR </li></ul><ul><li>Reactive routing: QoSAODV </li></ul><ul><li>Ticket-based Routing: TBP </li></ul><ul><li>Hierarchical Routing: CEDAR </li></ul><ul><li>Predictive & Location-based routing: PLQBR </li></ul><ul><li>Power aware routing </li></ul>
    9. 9. Proactive QoS Routing: QOLSR <ul><li>Optimized Link State Routing [RFC3626] </li></ul><ul><li>Aiming at large and dense MANETs with lower mobility </li></ul><ul><li>Only selected nodes as multi-point relays (MPRs) forwards broadcasting messages to reduce overhead of flooding </li></ul><ul><li>MPR nodes periodically broadcast its selector list </li></ul><ul><li>QoS extensions </li></ul><ul><ul><li>QOLSR [IETF Draft] : Hello messages and routing tables are extended with parameters of maximum delay and minimum bandwidth , and maybe more QoS parameters </li></ul></ul><ul><li>Advantage: ease of integration </li></ul><ul><li>in Internet infrastructure </li></ul><ul><li>Disadvantages: Overhead to keep </li></ul><ul><li>tables up to date </li></ul>Black nodes: MPRs
    10. 10. Reactive QoS Routing: QoS Enabled AODV <ul><li>AODV: Ad-hoc On-demand Distance Vector routing [RFC3561] </li></ul><ul><li>Best effort routing protocol </li></ul><ul><li>On need of a route, source node broadcasts route request(RREQ) packet </li></ul><ul><li>Destination, or an intermediate node with valid route to destination, responses with a route reply(RREP) packet. </li></ul><ul><li>QoS extensions [IETF Draft] : maximum delay and minimum bandwidth are appended in RREQ, RREP and routing table entry </li></ul><ul><li>Disadvantages </li></ul><ul><ul><li>No resource reservation, which unable to guarantee QoS </li></ul></ul><ul><ul><ul><li>Improved with bandwidth reservation: TDMA_AODV [7] </li></ul></ul></ul><ul><ul><li>Traversal time is only part of delay </li></ul></ul>RREQ1 (delay=100) RREQ1 (delay=70) RREQ1 (delay=20) RREP1 (delay=0) RREP1 (delay=50) RREP1 (delay=80) Delay(C->D)=50 QAODV example: Delay Requirement Source Node A Node B Traversal_time=30 Delay(B->D)=80 Node C Traversal_time=50 Dest. Node D RREQ2 (delay=20) Rejected!
    11. 11. Ticket-based Probing [5] : Features <ul><li>Objective: To find delay/bandwidth-constrained least-cost paths </li></ul><ul><li>Source-initiated path discovery, with limited tickets in probe packets to decrease overhead </li></ul><ul><li>Based on imprecise end-to-end state information </li></ul><ul><li>QoS metrics: Delay and bandwidth </li></ul><ul><li>Redundancy routes for fault tolerance during path break </li></ul><ul><li>Destination initiated Resource Reservation </li></ul>A B C D E p 1 (1) p 2 (2) p 3 (1) p 4 (1) p 4 (1) p 1 (1)
    12. 12. Tickets-relative Issues <ul><li>Colored tickets: yellow ones for smallest delay paths, green ones for least cost paths </li></ul><ul><li>For source node, how many tickets shall be issued? </li></ul><ul><ul><li>more tickets are issued for the connections with tighter or higher requirements </li></ul></ul><ul><li>For intermediate nodes, how to distribute and forward tickets? </li></ul><ul><ul><li>the link with less delay or cost gets more tickets </li></ul></ul><ul><li>How to dynamically maintain the multiple paths? </li></ul><ul><ul><li>the techniques of re-routing, path redundancy, and path repairing are used </li></ul></ul>
    13. 13. Disadvantages and Enhancement of TBP <ul><li>Enhanced TBP Algorithm [13] </li></ul><ul><ul><li>Color-based ticket Distribution </li></ul></ul><ul><ul><li>Ticket optimization using historical probing results </li></ul></ul><ul><li>Disadvantages </li></ul><ul><ul><li>Based on assumption of relatively stable topologies </li></ul></ul><ul><ul><li>Global state information maintenance with distance vector protocol incurs huge control overhead </li></ul></ul><ul><ul><li>Queuing delay and processing delay of nodes are not taken into consideration </li></ul></ul>Ticket blocking Color-based ticket distribution
    14. 14. Hierarchical Routing: CEDAR [6] <ul><li>Core Extraction Distributed Ad Hoc Routing </li></ul><ul><li>Oriented to small and middle size networks </li></ul><ul><li>Core extraction: A set of nodes is distributivedly and dynamically selected to form the core, which maintains local topology and performs route calculations </li></ul><ul><li>Link state propagation: propagating bandwidth availability information of stable high bandwidth links to all core nodes, while information of dynamic links or low bandwidth is kept local </li></ul><ul><li>QoS Route Computation: </li></ul><ul><ul><li>A core path is established first from dominator (neighboring core node) of source to dominator of destination </li></ul></ul><ul><ul><li>Using up-to-date local topology, dominator of source finds a path satisfying the requested QoS from source to furthest possible core node </li></ul></ul><ul><ul><li>This furthest core node then becomes the source of next iteration. </li></ul></ul><ul><ul><li>The above process repeats until destination is reached or the computation fails to find a feasible path. </li></ul></ul>
    15. 15. CEDAR: routing example G H D B F K E J C A S G H D B F K E J C A S G H D B F K E J C A S Links that node E aware of Partial Route constructed by B <ul><li>Core Node </li></ul><ul><li>Links that node B aware of </li></ul>Complete, with last 2 nodes determined by E Node S informs dominator B <ul><li>Disadvantages of CEDAR: </li></ul><ul><ul><li>Sub-optimal route </li></ul></ul><ul><ul><li>Core nodes being bottleneck </li></ul></ul>
    16. 16. Predictive Location-based QoS Routing: PLBQR [8] <ul><li>Motivation: to predict a future physical location based on previous location updates, which in turn to predict future routes </li></ul><ul><li>Update protocol: each node broadcasts its geographical update and resource information periodically and in case of considerable change </li></ul><ul><li>Location and delay prediction: </li></ul><ul><ul><li>Using similarity of triangles and </li></ul></ul><ul><ul><li>Pythagoras’ theorem, </li></ul></ul><ul><ul><li>(x p ,y p ) can be calculated </li></ul></ul><ul><ul><li>End-to-end delay from S to D </li></ul></ul><ul><ul><li>is predicted to be same as delay of latest update from D to S </li></ul></ul><ul><li>QoS routing </li></ul><ul><ul><li>Neighbor discovery with location-delay prediction </li></ul></ul><ul><ul><li>Depth-first search to find candidate routes satisfied QoS requirements </li></ul></ul><ul><ul><li>Geographically shortest route is chosen </li></ul></ul><ul><ul><li>Route is contained in data packets sent by source </li></ul></ul><ul><li>Disadvantages </li></ul><ul><ul><li>No resource reservation </li></ul></ul><ul><ul><li>Inaccuracy in delay prediction </li></ul></ul>Direction of motion Predicted location (x 2 , y 2 ) at t 2 (x 1 , y 1 ) at t 1 (x p , y p ) at t p v(t p -t 2 )
    17. 17. Power-aware QoS Routing <ul><li>Objective: </li></ul><ul><ul><li>to evenly distribute power consumption of each node </li></ul></ul><ul><ul><li>to minimize overall transmission power for each connection </li></ul></ul><ul><ul><li>to maximize the lifetime of all nodes </li></ul></ul><ul><li>Power-Aware Routing [9] : using power-aware metrics in shortest-cost routing </li></ul><ul><ul><li>Minimize cost per packet, with cost as functions of remaining battery power </li></ul></ul><ul><ul><li>Minimize max node cost of the path to delay node failure </li></ul></ul><ul><li>Maximum battery life routing [10] : Conditional Max-Min Battery Capacity Routing (CMMBCR) </li></ul><ul><ul><li>To choose shortest path if nodes in possible routes have sufficient battery </li></ul></ul><ul><ul><li>Avoiding routes going though nodes whose battery capacity is below threshold </li></ul></ul><ul><li>Energy Aware Routing [11] : selecting path according to its probability, which is inversely proportional to energy consumption, using sub-optimal paths to increase network survivability </li></ul>
    18. 18. Conclusion <ul><li>QoS routing is key issue in provision of QoS in Ad Hoc networks </li></ul><ul><li>Number of QoS routing approaches have been proposed in literature, focusing on different QoS metrics </li></ul><ul><li>No particular protocol provides overall solution </li></ul><ul><li>Some Open Issues </li></ul><ul><ul><li>QoS metric selection and cost function design </li></ul></ul><ul><ul><li>Multi-class traffic </li></ul></ul><ul><ul><li>Scheduling mechanism at source </li></ul></ul><ul><ul><li>Packet prioritization for control messages </li></ul></ul><ul><ul><li>QoS routing that allows preemption </li></ul></ul><ul><ul><li>Integration/coordination with MAC layer </li></ul></ul><ul><ul><li>Heterogeneous networks </li></ul></ul>
    19. 19. Primary References <ul><li>[1] T.Clausen, P.Jacquet, Optimized Link State Routing Protocol(OLSR), IETF RFC3626 , Oct.2993. </li></ul><ul><li>[2] H.Badis, K.Agha, Quality of Service for Ad hoc Optimized Link State Routing Protocol (QOLSR), IETF Draft , Oct.2005 </li></ul><ul><li>[3] C.Perkins, E. Royer and S. Das, Ad hoc On-Demand Distance Vector (AODV) Routing, IETF RFC3561 , Oct.2993. </li></ul><ul><li>[4] C.Perkins, E. Royer and S. Das, Quality of Service for Ad hoc On-Demand Distance Vector Routing, IETF Draft , Jul.2000. </li></ul><ul><li>[5] S.Chen,K.Nahrstedt, Distributed Quality-of-Service Routing in Ad Hoc Network, IEEE Journal on Selected Areas in Commun, Aug 1999. </li></ul><ul><li>[6] R.Sivakumar, P.Sinda and V. Bharghavan, CEDAR: A Core-Extraction Distributed Ad Hoc Routing Algorithm, IEEE Journal on Selected Areas in Commun, Aug 1999 . </li></ul><ul><li>[7] C.Zhu, M.Corson, QoS routing for mobile ad hoc networks, IEEE Infocom 2002. </li></ul><ul><li>[8] S.Shah, K.Nahrstedt, Predictive Location-Based QoS Routing in Ad Hoc Networks, IEEE ICC 2002 . </li></ul><ul><li>[9] S. Singh, M.Woo and C.Raghavendra, Power-aware Routing in Mobile Ad Hoc Networks, MOBICOM’98 . </li></ul><ul><li>[10] C. Toh, Maximum Battery Life Routing to Support Ubiquitous Mobile Computing in Wireless Ad Hoc Networks, IEEE commun, Magazine , Jun 2001. </li></ul><ul><li>[11] R Shah, J.Rabaey, Energy Aware Routing for Low Energy Ad Hoc Sensor Networks, IEEE WCNC 2002. </li></ul>
    20. 20. Secondary References <ul><li>[12] S.Chen,K.Nahrstedt, Distributed QoS Routing with Imprecise State Information, IEEE ICCCN’98. </li></ul><ul><li>[13] L.Xiao,J.Wang and K.Nahrstedt, The Enhanced Ticket-based Routing Algorithm, IEEE ICC , 2002 </li></ul><ul><li>[14] C.Murthy, B.Manoj, Ad Hoc Wireless Networks, Pentice Hall , 2004 </li></ul><ul><li>[15] M.Ilyas, I.Mahgoub, Mobile Computing Handbook, Auerbach Publications , 2005 </li></ul><ul><li>[16] S.Chakrabarti, A.Mishra, QoS Issues in Ad Hoc Wireless Networks, IEEE Commun. Magzine, Feb. 2001 </li></ul>
    21. 21. Thanks for your time Any Questions?