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3.1 Resultat Resultaten som simulatorn indikerar är lovande. Figur 3-5 visar andelen mottagna meddelanden av de skickade. När hastigheten ökas från 0 till 10 meter per sekund sjunker andelen en aning tills 5 m/s är nås. Därefter avtar minskningen en aning tills 8 m/s nås. Detta fenomen verkar finnas i de andra graferna också. 
Fig. 3-5 
Fig. 3-6 Grafen i figur 3-6 visar att mycket få RQM-meddelanden skickas även under höga hastigheter. Tiden det tar att upptäcka rutter till destinationer i medeltal är uppvisad i figur 3-7. Grafen verkar vara mera självständig från de andra med en större standardavvikelse. 
Fig. 3-7 Varje graf visar en försämring av resultaten från 0 - 5 m/s. Därefter blir resultaten bättre ända tills 8 m/s är nås. Det är möjligt att hastigheten i det skedet är så hög att inte båda RQMen misslyckas med att hitta sin destination, d.v.s. en ny rutt har bildats när det andra RQMet försöker hitta sin destination. Latenstiden för att hitta rutter är kort, men ännu kortare kunde man göra den med aktiv ruttföråldring på samma sätt som AODV. Resultaten är inte direkt jämförbara med andra protokoll men de indikerar goda egenskaper som kommer att kunna bli grunden för ett bra protokoll. References [Lei+97] Ad Hoc Networking with Mobile IP, Hue Lei and Charles E Perkins, Proceedings of 2nd European Personal Mobile Communication Conference, 1997. [Perkins+01] Ad Hoc Networks, Charles E Perkins, Addison-Wesley, 2001. [Karn90] A new Channel Access Method for Packet Radio, P. Karn, ARRL/CRRL Amateur Radio 9th Computer Networking Conference, Sept. 22 1990. [Bakre+95] I-TCP: Indirect TCP for mobile hosts, A. Bakre and B. Badrinath, Proc. 15th Intl. Conf. on Distributed Computing Systems (ICDCS), Vancouver, Canada, May 1995. [Kim+01] TCP-BuS: Improving TCP Performance in Wireless Ad Hoc Networks, Dongkyun Kim, C.-K. Toh, and Yanghee Choi, Journal of Communications and Networks, vol3, no.2, June 2001. [Stevens97] RFC 2001: TCP Slow Start, Congestion Avoidance, Fast Retransmit, and Fast Recovery Algorithms, W. Stevens, 1997. [Chandran+98] A Feedback Based Scheme For Improving TCP Performance In Ad-Hoc Wireless Networks, Kartik Chandran, Sudarshan Raghunathan, S. Venkatesan, Ravi Prakash, The 18th International Conference on Distributed Computing Systems, Amsterdam, Netherlands, 1998. [Toh02] Ad Hoc Wireless Mobile Wireless Networks, C-K Toh, Prentice Hall PTR, 2002. [IEEE99] ANSI/IEEE Std 802.11, 1999 Edition. [Bharghavan+94] MACAW: A Media Access Protocol for Wireless LAN's 1994, Vaduvur Bharghavan, Alan Demers, Scott Shenker, Lixia Zhang, ACM SIGCOMM Computer Communication Review Volume 24 Issue 4, October 1994. [Talucci+97] MACA-BI (MACA by invitation) - A Receiver Oriented Access Protocol for Wireless Multihop Networks, F. Talucci, M. Gerla, and L. Fratta, Proceedings of IEEE PIMRC, 1997. [Singh+98] PAMAS: Power-Aware Multi-Access protocol with Signalling for Ad Hoc Networks, S. Singh and C. S. Raghavendra. ACM Computer Communication Review, July 1998. [Deng+98] Dual Busy Tone Multiple Access (DBTMA): A New Medium Access Control for Packet Radio Networks, J. Deng and Z. Haas, Florence, Italy, 1998. [Bao+02] Hybrid Channel Access Scheduling in Ad Hoc Networks, Lichun Bao J.J. Garcia-Luna-Aceves, Proceedings of the 10th IEEE International Conference on Network Protocols, 2002. [Tanenbaum03] Computer Networks Fourth Edition, Andrew S Tanenbaum, Prentice Hall PTR, 2003. [Lin+95] A Distributed Control Scheme in Multi-hop Packet Radio Networks for Voice/Data Traffic Support, Chun-hung Richard Lin and Mario Gerla, Proceedings of IEEE ICC, 1995. [Hu93] Distributed Code Assignments for CDMA Packet Radio Networks, Limin Hu, Member, IEEE/ACM Transactions on Networking, vol. 1, No. 6, December 1993. [Ibáñez] Unicast Routing Protocols for Mobile Ad Hoc Networks (MANETs): Overview, issues and perspectives, Guillermo Ibáñez, Telemática Universidad Carlos III de Madrid. [Kim+02] Performance analysis of power-aware route selection protocols in mobile ad hoc networks, Dongkyun Kim, J.J. Garcia-Luna-Aceves, Katia Obraczka, Juan-Carlos Cano and Pietro Manzoni, Proceedings of the 5th ACM international workshop on Modeling analysis and simulation of wireless and mobile systems, Atlanta USA, 2002. [Perkins+99] Ad-hoc On-Demand Distance Vector Routing, Charles E. Perkins, Elizabeth M. Royer, Proceedings of the 2nd IEEE Workshop on Mobile Computing Systems and Applications, New Orleans, February 1999. [Johnson+96] Dynamic Source Routing in Ad Hoc Wireless Networks, D.B. Johnson and D.A. Maltz, Mobile Computing, chapter 5, pp.153-181, Kluwer Academic Publishers, 1996. [Tschudin+00] Active Routing for Ad Hoc Networks, Christian Tschudin and Henrik Lundgren, Uppsala University, Henrik Gulbrandsen, Ericsson Research, x IEEE Communications, 2002. 1 This text talks almost exclusively about multi-hop networks, which means that intermediate hosts must relay messages between hosts not in direct contact of each other. This is called forwarding. 2 The MAC layer is a sub layer of the data link layer, which is the second layer in the OSI model. 3 802.11b does not specify how the secret keys should be distributed. 4 Advanced Configuration Power Interface (ACPI) and Operating System Power Management ( OSPM) 5 Defense Advanced Research Projects Agency 6 The transmission technique is specified at the physical layer. 7 FHSS in IEEE 802.11b hops between 79 frequency channels; each is 1 MHz wide every 400msec (or less) and transfers data at max. 11Mbps. 8 Bluetooth (as do 802.11) operates in the 2.4 GHz ISM band of 83.5 MHz in which 79 RF channels spaced 1 MHz apart are available for frequency hopping spread spectrum. 9 Bluetooth devices are identified with a 48bit MAC address. 10 Internet Engineering Task Force 11 Data link layer consists of the logical link control layer and the MAC layer. 12 Poisoned-reverse & split horizon 13 The word bandwidth is used here to denote the data transfer rate. 14 A node in promiscuous mode registers every packet it hears even if it is not addressed to the node. 15 This picture is part of a demonstration found at the OLSR homepage http://menetou.inria.fr/olsr/mpr-flooding.html 16 Proactive protocols can be either a link state or distance vector type protocol. Reactive schemes cannot be of link state type. Examples of reactive schemes are distance vector and source routing. 17 MAC nivån är en under nivå av data link nivån som år den andra nivån i OSI modellen. Download 298.62 Kb. Share with your friends:
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