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  1. 1. DILLA UNIVERSITY COLLEGE OF ENGINEERING & TECHNOLOGY School of Computing & Informatics M. Sc in Computer Science & Networking By Chapter-03 COET, Dilla University 1 Course Number CN6117 Course Title Mobile Computing
  2. 2. Mobile Computing CHAPTER-03 1. Mobile ad-hoc networks 2. Mobile IP COET, Dilla University 2
  3. 3. 1. MOBILE AD-HOC NETWORKS  MANET stands for Mobile adhoc Network also called as wireless adhoc network or adhoc wireless network that usually has a routable networking environment on top of a Link Layer ad hoc network.  They consist of set of mobile nodes connected wirelessly in a self configured, self healing network without having a fixed infrastructure.  MANET nodes are free to move randomly as the network topology changes frequently.  Each node behaves as a router as they forward traffic to other specified node in the network. COET, Dilla University 3
  4. 4. Cont..  MANET may operate as standalone fashion or they can be the part of larger internet.  They form highly dynamic autonomous topology with the presence of one or multiple different transceivers between nodes.  The main challenge for the MANET is to equipped each devices to continuously maintain the information required to properly route traffic.  MANETs consist of a peer-to-peer, self-forming, self- healing network MANET’s typically communicate at radio frequencies (30MHz-5GHz).  This can be used in road safety, ranging from sensors for the environment, home, health, disaster rescue operations, air/land/navy defense, weapons, robots, etc. COET, Dilla University 4
  5. 5. MANET (Mobile Ad Hoc Networks) • Formed by wireless hosts which may be mobile • No pre-existing infrastructure • Routes between nodes may potentially contain multiple hops – Nodes act as routers to forward packets for each other – Node mobility may cause the routes change A B C D A B C D 5 COET, Dilla University
  6. 6. • Advantages: low-cost, flexibility – Ease & Speed of deployment – Decreased dependence on infrastructure • Applications – Military environments • soldiers, tanks, planes – Civilian environments • vehicle networks • conferences / stadiums • outside activities – Emergency operations • search-and-rescue / policing and fire fighting Why MANET? 6 COET, Dilla University
  7. 7. • Collaboration – Collaborations are necessary to maintain a MANET and its functionality. – How to collaborate effectively and efficiently? – How to motivate/enforce nodes to collaborate? • Dynamic topology – Nodes mobility – Interference in wireless communications Challenges 7 COET, Dilla University
  8. 8. 8 Comparison • MANETs vs. Wired networks – In MANETs, each node also works as router for forwarding packets – In wired networks, routers perform routing task • MANETs vs. Managed wireless networks – No infrastructure in MANETs – Special node known as access point (AP) in managed wireless networks COET, Dilla University
  9. 9. MANETS COET, Dilla University 9
  10. 10. Characteristics of MANET  Dynamic Topologies  Bandwidth constrained, variable capacity links  Autonomous Behavior  Energy Constrained Operation  Limited Security  Less Human Intervention COET, Dilla University 10
  11. 11. Cont.. Dynamic Topologies: Network topology which is typically multi hops, may change randomly and rapidly with time, it can form unidirectional or bi-directional links. Bandwidth constrained, variable capacity links: Wireless links usually have lower reliability, efficiency, stability, and capacity as compared to wired network. The throughput of wireless communication is even less than a radio’s maximum transmission rate after dealing with the constraints like multiple access, noise, interference conditions, etc. Autonomous Behavior: Each node can act as a host and router, which shows its autonomous behavior. COET, Dilla University 11
  12. 12. Cont.. Energy Constrained Operation: As some or all the nodes rely on batteries or other exhaustible means for their energy. Mobile nodes are characterized with less memory, power, and lightweight features. Limited Security: Wireless network are more prone to security threats. A centralized firewall is absent due to its distributed nature of the operation for security, routing, and host configuration. Less Human Intervention: They require minimum human intervention to configure the network, therefore they are dynamically autonomous in nature. COET, Dilla University 12
  13. 13. Types of MANETs  Vehicular Ad hoc Network (VANETs)  Smart Phone Ad hoc Network (SPANC)  Internet based Mobile Ad hoc Network (iMANETs)  Hub-Spoke MANET  Military or Tactical MANETs  Flying Ad hoc Network (FANETs) COET, Dilla University 13
  14. 14. Cont.. Vehicular Ad hoc Network (VANETs) • Enable effective communication with another vehicle or with the roadside equipments. • Intelligent vehicular ad hoc networks(InVANETs) deals with another vehicle or with the roadside equipments. Smart Phone Ad hoc Network (SPANC) • To create peer-to-peer network without relying on cellular carrier networks, wireless access points or traditional network infrastructure. • Here peer can join or leave the network without destroying it. Internet based Mobile Ad hoc Network (iMANETs) • It supports internet protocols such as TCP/UDP and IP. • To link mobile nodes and establish routes distributed and automatically. COET, Dilla University 14
  15. 15. Cont.. Hub-Spoke MANET • Multiple sub MANET’s may be connected in hub-spoke VPN to create a geographically distributed MANET. • Normal Ad-hoc routing algorithm does not apply directly. Military or Tactical MANETs • This is used by the military units. • Emphasis on data rate, real time demand, fast re-routing during mobility, security, radio range, etc. Flying Ad hoc Network (FANETs) • This is composed of unmanned aerial vehicle (commonly known as drone). • Provides links to remote areas and mobility. COET, Dilla University 15
  16. 16. Benefits of MANET  Highly suitable network in such circumstances where fixed infrastructure is too much costly, untrustworthy, not trusted and due to unavailability of such a network.  Quickly installation with least possible user intervention.  Detailed planning and installation of base stations is not required.  Ad hoc networks can be attached to the WWW or Internet, thereby incorporating many different devices and making possible for other users to use available services.  Capacity, range and energy arguments promote their use in tandem with existing cellular infrastructures as they can extend coverage and interconnectivity.  MANET also fitted to use the 4G architecture and their services, aims to provide ubiquitous computer environments that support users in completing their tasks, accessing information and communicating anywhere , anytime and from any device . COET, Dilla University 16
  17. 17. Applications of MANET Some distinctive MANET applications include: • Military field • Cooperative work • Confined level • PAN and Bluetooth • Business Sector • Sensor Networks • Backup Services • Educational sector COET, Dilla University 17
  18. 18. Cont.. Military field: Ad-Hoc networking can permit army to exploit benefit of conventional network expertise for preserving any info network among vehicles, armed forces, and headquarters of information. Cooperative work: To facilitate the commercial settings, necessity for concerted computing is very significant external to office atmosphere and surroundings as compared to inner environment. People want getting outside meetings for exchanging the information plus cooperating with each other regarding any assigned task. Confined level: Ad-Hoc networks are able to freely associate with immediate, in addition momentary hypermedia network by means of laptop computers for sharing the info with all the contestants’ e.g. classroom and conference. Additional valid and confined level application may be in domestic network where these devices can interconnect straight in exchanging the information. COET, Dilla University 18
  19. 19. Cont.. PAN and Bluetooth: A PAN(Personal Area Networks) is localized and tiny range network whose devices are generally belong to a specified individual. Limited-range MANET such as Bluetooth can make simpler the exchange among several portable devices like a laptop, and a cell phone. Business Sector: Ad-hoc network could be used for rescuing and emergency processes for adversity assistance struggles, for instance, in flood, fire or earthquake. Emergency saving procedures should take place where damaged and non- existing transmissions structure and quick preparation of a transmission network is required. Sensor Networks: Managing home appliances with MANETs in both the case like nearby and distantly. Tracking of objects like creatures. Weather sensing related activities. COET, Dilla University 19
  20. 20. Cont.. Backup Services: liberation operations, tragedy recovery, diagnosis or status or record handing in hospitals, replacement of stationary infrastructure. Educational sector: arrangement of communications facilities for computer-generated conference rooms or classrooms or laboratories. COET, Dilla University 20
  21. 21. Challenges in Mobile Environments  Limitations of the Wireless Network  packet loss due to transmission errors  variable capacity links  frequent disconnections/partitions  limited communication bandwidth  Broadcast nature of the communications  Limitations Imposed by Mobility  dynamically changing topologies/routes  lack of mobility awareness by system/applications  Limitations of the Mobile Computer  short battery lifetime  limited capacities 21 COET, Dilla University
  22. 22. Routing  Routing is the process of selecting a path for traffic in a network or between or across multiple networks.  Packet forwarding is the transit of network packets from one network interface to another.  Intermediate nodes are typically network hardware devices such as routers, gateways, firewalls, or switches. COET, Dilla University 22
  23. 23. Routing protocol  A routing protocol specifies how routers communicate with each other to distribute information that enables them to select routes between any two nodes on a computer network.  A routing protocol shares this information first among immediate neighbors, and then throughout the network. COET, Dilla University 23
  24. 24. MANET Main Classification Reactive On-Demand Proactive Table-Driven Hybrid •DSDV •WARP •DREAM •DSR •AODV •TORA •ZRP •HARP Ad Hoc Routing Protocols Main Classification 24 COET, Dilla University
  25. 25. 25 Proactive Protocols Proactive: maintain routing information independently of need for communication • Update messages send throughout the network periodically or when network topology changes. • Low latency, suitable for real-time traffic • Bandwidth might get wasted due to periodic updates COET, Dilla University
  26. 26. 26 On-Demand or Reactive Routing • Reactive: discover route only when you need it • Saves energy and bandwidth during inactivity • Can be bursty -> congestion during high activity • Significant delay might occur as a result of route discovery • Good for light loads, collapse in large loads COET, Dilla University
  27. 27. 27 Hybrid Routing • Proactive for neighborhood, Reactive for far away (Zone Routing Protocol, Haas group) • Proactive for long distance, Reactive for neighborhood (Safari) • Attempts to strike balance between the two COET, Dilla University
  28. 28. MANET Routing Protocols Classification Source: MINEMA Uniform routing Proactive routing Wireless Routing Protocol (WRP) Destination Sequence Distance Vector (DSDV) routing protocol Fisheye State Routing (FSR) Distance Routing Effect Algo. for Mobility (DREAM) Location-based routing Reactive routing Dynamic Source Routing (DSR) protocol Temporally-Ordered Routing Algorithm (TORA) Adhoc On-demand Distance Vector Routing (AODV) Location Aided Routing (LAR) Location-based routing Associativity Based Routing (ABR) protocol Link-stability based routing protocol Signal Stability-base adaptive Routing (SSR) Link-stability based routing protocol Non-uniform routing Zone-based routing Zone Routing Protocol (ZRP) Hybrid routing protocol Hybrid Adhoc Routing Protocol (HARP) Hybrid routing protocol Zone-based Hierarchical Link State routing (ZHLS) Hybrid routing protocol Grid Location Service (GLS) Location service Cluster-based routing Clusterhead Gateway Switch Routing (CGSR) Hierarchical State Routing (HSR) Cluster Based Routing Protocol (CBRP) Core-node based routing Landmark Adhoc Routing (LANMAR) Proactive routing Core-Extraction Distributed Adhoc Routing (CEDAR) Proactive routing Optimised Link State Routing protocol (OLSR) Proactive routing COET, Dilla University
  29. 29. 2. Mobile IP COET, Dilla University 29
  30. 30. 2. Mobile IP Mobile IP (or MIP) is an Internet Engineering Task Force (IETF) standard communications protocol that is designed to allow mobile device users to move from one network to another while maintaining a permanent IP address. COET, Dilla University 30
  31. 31. COET, Dilla University Why Mobile IP? • What do cellular networks and wireless LANs provide? – Wireless connectivity – Mobility at the data link layer • What is Dynamic Host Configuration Protocol (DHCP)? – It provides local IP addresses for mobile hosts – Is not secure – Does not maintain network connectivity when moving around • What they do not provide: – Transparent connectivity at the network layer – Mobility with local access
  32. 32. COET, Dilla University 6.32 What is Mobile IP? • Mobile IP provides network layer mobility • Provides seamless roaming Ability that a user roams in a secure way across, different networks while keeping connected and not disturbing ongoing sessions and conversations. • ‘‘Extends’’ the home network over the entire Internet
  33. 33. COET, Dilla University 6.33 What Mobile IP does: • Mobile IP solves the following problems – if a node moves without changing its IP address it will be unable to receive its packets, – if a node changes its IP address it will have to terminate and restart its ongoing connections every time it moves to a new network area (new network prefix). • Mobile IP is a routing protocol with a very specific purpose. • Mobile IP is a network layer solution to node mobility in the Internet. • Mobile IP is not a complete solution to mobility, changes to the transport protocols need to be made for a better solution
  34. 34. Requirements to Mobile IP (RFC 2002) • Transparency – mobile end-systems keep their IP address – continuation of communication after interruption of link possible – point of connection to the fixed network can be changed • Compatibility – support of the same layer 2 protocols as IP – no changes to current end-systems and routers required – mobile end-systems can communicate with fixed systems • Security – authentication of all registration messages • Efficiency and scalability – only little additional messages to the mobile system required (connection typically via a low bandwidth radio link) – world-wide support of a large number of mobile systems in the whole Internet 34 COET, Dilla University
  35. 35. COET, Dilla University 6.35 Mobile IP Terminology • Mobile Node (MN) – system (node) that can change the point of connection to the network without changing its IP address • Home Agent (HA) – system in the home network of the MN, typically a router – registers the location of the MN, tunnels IP data grams to the COA • Foreign Agent (FA) – system in the current foreign network of the MN, typically a router – forwards the tunneled datagrams to the MN, typically also the default router for the MN • Care-of Address (COA) – address of the current tunnel end-point for the MN (at FA or MN) – actual location of the MN from an IP point of view – can be chosen, e.g., via DHCP • Correspondent Node (CN) – communication partner
  36. 36. Mobile IP Diagram COET, Dilla University 36
  37. 37. Cont.. COET, Dilla University 37
  38. 38. 38 Mobile IP • Three Mobile IP mechanisms – 1. Discovering – 2. Registering – 3. Tunneling COET, Dilla University
  39. 39. 39 Mobile IP (cont) 1. Discovery – Extension of ICMP Router Advertisement – Home agents and foreign agents broadcast agent advertisements at regular intervals – Agent advertisement Allows for the detection of mobility agents Lists one or more available care-of addresses Informs the mobile node about special features Mobile node selects its care-of address Mobile node checks whether the agent is a home agent or foreign agent COET, Dilla University
  40. 40. 40 Mobile IP Agent Advertisement Message COET, Dilla University
  41. 41. 41 Mobile IP (cont) • 2. Registration – Once a mobile node has a care-of address, its home agent must find out about it COET, Dilla University
  42. 42. 42 Registration request Message Registration reply Message COET, Dilla University
  43. 43. 43 Mobile IP (cont) • Secure the Registration Procedure – The home agent must be certain registration was originated by the mobile node and not by some malicious node – Security association: Message Digest 5 (MD5) – Replay attacks A malicious node could record valid registrations for later replay, effectively disrupting the ability of the home agent to tunnel to the current care-of address of the mobile node at that later time Identification field that changes with every new registration Use of timestamp or random numbers COET, Dilla University
  44. 44. 44 Message Digest 5 (MD5) • One-Way Hash Function – With some good properties, … – Produces a 128-bit message digest • Example – Two communicating parties A and B – A and B share a common secret value SAB – When A has a message (M) to send to B, it calculate MDM = H(SAB || M) – It then sends [ M || MDM ] to B – Because B possesses SAB, it can re-compute H(SAB || M) and verify MDM. COET, Dilla University
  45. 45. 45 Mobile IP (cont) 3. Tunneling to the care-of address COET, Dilla University
  46. 46. 46 Two Tunneling Methods IP-within-IP Encapsulation Minimal Encapsulation COET, Dilla University
  47. 47. 47 Mobile IPv6 • Mobility support in IPv6 – Follows the design for Mobile IPv4, using encapsulation to deliver packets from the home network to the mobile point of attachment • Route Optimization – Similar to IPv4 – Delivering binding updates directly to correspondent nodes (home address, care-of address, registration lifetime) • Security – IPv6 nodes are expected to implement strong authentication and encryption features COET, Dilla University
  48. 48. 48 Problems facing Mobile IP • Routing inefficiencies – Asymmetry in routing: Triangle routing – Route optimization requires changes in the correspondent nodes that will take a long time to deploy • Security issues – Firewalls Blocks all classes of incoming packets that do not meet specified criteria It presents difficulties for mobile nodes wishing to communicate with other nodes within their home enterprise networks COET, Dilla University
  49. 49. References Reference Text Books: • J. Schiller, Mobile Communications, Addison Wesley, 2003. • Alexander Kukushkin, Introduction to Mobile Network engineering GSM,3G-WCDMA, LTE and the Road to 5G, Wiley COET, Dilla University 49
  50. 50. THANK YOU COET, Dilla University 50