1 / 34

MIPMANET – Mobile IP for Mobile Ad Hoc Networks

MIPMANET – Mobile IP for Mobile Ad Hoc Networks. J ö sson, Alriksson, Larsson, Johansson, and Maguire IEEE MOBIHOC 2000. Abstract. I. INTRODUCTION. Motivation Mobility and IP are two strong trends nowadays.

galeno
Download Presentation

MIPMANET – Mobile IP for Mobile Ad Hoc Networks

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MIPMANET – Mobile IP for Mobile Ad Hoc Networks Jösson, Alriksson, Larsson, Johansson, and Maguire IEEE MOBIHOC 2000

  2. Abstract

  3. I. INTRODUCTION • Motivation • Mobility and IP are two strong trends nowadays. • Desire for mobility concerning access to information on the Internet is increasing. • The need to utilize Ad-hoc network and Mobile IP • Ad hoc network • Formed on temporary basis • Easy to set up • Can operate without any preexisting infrastructure • Untethered multihop communication • IETF MANET (Mobile Ad-hoc Network) working group • Mobile IP allows roaming between different networks.

  4. I. INTRODUCTION -2 • This paper looks into • how an ad-hoc network using on-demand routing can be connected to the Internet • and how to provide roaming service that Mobile IP enables. • This paper proposes a solution called MIPMANET (Mobile IP for Mobile Ad-hoc Network) • Simulation • Using Network Simulator 2 (ns-2) • Using AODV (Ad-hoc On-demand Distance Vector) routing algorithm within ad-hoc networks

  5. II. PROTOCOL DESCRIPTIONS • A. Mobile IP • Proposed for location independent routing • Makes mobility transparent for the applications and higher level protocols like TCP and UDP • Allows mobile nodes to have seamless and untethered access to the Internet while roaming between different networks

  6. II. PROTOCOL DESCRIPTIONS -2 • Every mobile node is registered to its home agent (HA) in the home network and is assigned a home address. • When the mobile node (visiting node, VN) is attached to a network other than its home network (foreign network), it must register to a foreign agent (FA) with its home address and its authentication. The FA notifies and authenticates to the HA of the VN. • The VN then uses the care-of address, which is the address of the FA. • When a node, the corresponding node (CN), tries to send packets to a VN, it first sends packets to the HA of the VN. The HA tunnels the packets to the FA and informs CN about the care-of address of the VN so that the CN can tunnel subsequent packets directly to FA.

  7. II. PROTOCOL DESCRIPTIONS -3 • The need of care-of address for VN • All nodes in the same network use the same network ID of the IP address. • VN needs an care-of address that is accessible in the FN, e.g. DHCP can be used. • Selecting a FA • FA broadcasts Agent Advertisement periodically for a VN to select the FA. • VN broadcasts Agent Solicitation. FA receiving Agent Solicitation unicasts Agent Advertisement to the requesting VN.

  8. II. PROTOCOL DESCRIPTIONS -4 B. AODV • A distance vector routing protocol for ad-hoc networks, that operates on-demand. • Distance Vector • Using traditional routing table, one entry per destination, but without periodic routing table exchanges. • Only the nodes that lie on the path between the two end nodes keep information about the route. • On-demand • Routes are only set up when a node wants to communicates with some other node.

  9. II. PROTOCOL DESCRIPTIONS -5 • On-demand routing • When a node wants to communicates with a destination, it initiates route discovery, by flooding with Route Request (RREQ) packets. • Every node receiving RREQ looks in its routing table to see if it is the destination or it has a fresh route to that destination. • If it does, it unicasts a Route Reply (RREP) back to the source through the reverse route created by the RREQ, otherwise it rebroadcasts the RREQ. • It keeps a set of predecessor nodes for each entry, indicating the set of neighboring nodes that use that entry to route packets.

  10. II. PROTOCOL DESCRIPTIONS -6 • Local connectivity maintenance • Each node keeps track of its local connectivity, i.e. its neighbors, by either • Periodic exchange of HELLO messages, or • Feedback from the data link layer upon unsuccessful transmission. • If a node detects the next hop node of some routes is unreachable, it will propagate an Route Error (RERR) message to all the upstream neighbors of these routes. • A node receiving a RERR message will do the same connectivity check and will propagate RERR further toward the source.

  11. II. PROTOCOL DESCRIPTIONS -7 • Table freshness maintenance and routing loop check • Each entry has a sequence number. • All routing packets carry this sequence. • The entry is expired if it is not used recently. • Every packets are checked to see if it passes twice.

  12. III. INTERNET ACCESS A. Route and Address • Traditional Internet routing • All nodes in the same network use the same network ID of the IP address. • To use one route for the entire network • Ad-hoc network routing • Nodes in an ad hoc network may have different network Ids • Since data link connectivity with all other nodes is not possible, thus IP layer routing must be used. • On-demand routing has been shown preferable

  13. III. INTERNET ACCESS -2 • Problems in routing for ad-hoc networks • Can’t route using network ID of a node. • No routes are known beforehand for on-demand routing. • The destination may be found unreachable after route discovery. • How to make a node reachable for the Internet?[Sol.] A border node with reachable IP address is needed between an ad-hoc network and the fixed Internet.

  14. III. INTERNET ACCESS -3 B. Mobile IP • Since ordinary Mobile IP was designed primarily for the fixed Internet and the wireless leaf networks, problems arise when applying to ad hoc networks: • B.1 Implications of Multihop Communication • Instead of using link-layer connectivity, FA and VN must use network-layer routing. • Broadcasts are more costly (bandwidth and energy) for a multihop ad hoc network than on a single link. • To select among several possible FA’s by the quality of multiple links, not by a single link. • Nodes not using Mobile IP suffer with the flooding of Agent Advertisements and Agent Solicitations. • B.2 Implications of On-Demand Routing • Mobile IP uses proactive routing, while many promising routing protocols for ad hoc networks are on-demand.

  15. IV. MIPMANET • To use Mobile IP foreign agents as the access points to the Internet • To keep track of in which ad hoc network a node is located • To direct packets to the border of that ad hoc network • Ad hoc routing protocol is used to deliver packets between FA and VN. • A layered approach with tunneling is used for the outward data flow to separate the Mobile IP functionality and the ad hoc routing protocol.

  16. IV. MIPMANET -2 • MIPMANET works as follows: • VN registers to a FA with its home address • To send a packet to the Internet: • Tunnel the packet to the FA • To receive packets from a host on the Internet: • The packets are routed to the FA by the ordinary Mobile IP mechanism • The FA will then deliver the packets to the node in the ad hoc network • Nodes that do not need Internet access will see the ad hoc network as a stand-alone network

  17. IV. MIPMANET -3 • The layering of Mobile IP and ad hoc routing functionality is illustrated in Fig. 1. • By the use of tunneling, the ad hoc network becomes transparent to the Mobile IP.

  18. IV. MIPMANET -4 • A. Foreign Agents and Tunneling • Using a single care-of address, a node with arbitrary home address can attach to any ad hoc network. • Since an ad hoc network dose not have a network ID, it is not possible to decide whether a destination is located within the same ad hoc network or not by simply looking at the destination’s network ID. • MIPMANET lets the route discovery mechanism of the ad hoc network search for the destination within the ad hoc network. If the destination is not within the same ad hoc network, the packet is tunneled to the FA by the ad hoc routing mechanism. • If a node is not registered to any FA, the destination is considered to be unreachable.

  19. IV. MIPMANET -5 • Only registered VN’s get Internet access. • The only traffic that will enter the ad hoc network from the Internet is the traffic that is tunneled from the HA of a registered VN. • The only traffic that will leave the ad hoc network is the traffic that is tunneled to the FA from a registered VN.

  20. IV. MIPMANET -6 B. Adapting Mobile IP • Instead of using link-layer addresses, network-layer identifier, i.e. IP addresses, must be used. • B.1 Periodic Agent Advertisement • In ordinary Mobile IP, the minimum time between two consecutive Agent Advertisements is 1 second. • In ad hoc networks, every periodic advertisement involves flooding, thus the advertisement period should be longer. (5 seconds is used in the simulation)

  21. IV. MIPMANET -7 • B.2 Movement Detection • ∵Multiple hops between FA’s and VN’s.∴None of the movement detection methods provided by Mobile IP is suitable. • Lazy Cell Switching (LCS): • A node should stick to a FA for as long as possible • Eager Cell Switching (ECS) • It assumes movement along a straight line • It does not allow a VN to switch back and forth between two FA’s. • MIPMANET uses hop count as the metric to decide whether to switch FA’s. • A registered VN should register to another FA if it is two hops closer to this FA than to the FA currently registered.

  22. IV. MIPMANET -8

  23. IV. MAC PROTOCOL -2 • B. MAC Signaling • The radio capacity with OFDM-CDMA is structured as • Korthogonal codes that can be used simultaneously. • Each code is used in a time-division multiple-access fashion; a time slot carries a MAC_PDU (TSLOT = TMAC_PDU). • [RT ID, Other Info., Data Load] • Time is structured into frames (TFRAME) lasting N time slots by K * N * MAC_PDUs. • The structure is referred to as the TC-matrix (time slots-code matrix).

  24. IV. MAC PROTOCOL -4 • The capacity assignment is performed frame by frame. • Each RT can transmit (uplink) on several time slot-code pairs (TC-pairs) without restrictions.

  25. IV. MAC PROTOCOL -5 • The basic MAC signaling consists of • the request channel (ReqCh) • an UL ( Uplink Logical) channel to make capacity requests • the allocation channel (AlCh) • a DL (Downlink Logical) channel to answer the requests • The ReqCh and AlCh is structured in minislots. • A ReqCh-AlCh minislot pair is dedicated to each RT.

  26. IV. MAC PROTOCOL -6 • The ReqCh in UL is structured in minislots: • Each minislot contains the bandwidth request. • [RT ID, Request GB Class, Request BE Class] • The request issued in the kth frame by each RT is just the number of MAC_PDUs of each service class found in the RT at the beginning of the kth frame for which there is no pending request.

  27. IV. MAC PROTOCOL -7 • The AlCh in DL has the same minislot structure as the ReqCh. • Each minislot contains the allocation reply. • [Starting Code, Starting Offset, No. of TC-pairs] • The RN uses the AlCh to signal to each RT • the number of assigned TC-pairs, • the starting code (the row of the TC-matrix) • the starting offset in the code row. • A ReqCh-AlCh minislot pair is dedicated to each RT. • Detailed format and dimensioning of ReqCh and AlCh are re-ported in [14].

  28. IV. MAC PROTOCOL -3 (1) UL Request Channel RN to RT (2) DL Allocation Channel RT to RN (N =3)

  29. V. THE FWA SYSTEM AS AN ACCESS RSVP CLOUD

  30. VI. PERFORMANCE ANALYSIS

  31. VII. CONCLUSION

More Related