This study is a comparison of three routing protocols proposed for wireless mobile ad-hoc networks.The protocols are: Destination Sequenced Distance Vector (DSDV), Ad-hoc On demand Distance Vector (AODV) and Dynamic Source Routing (DSR).Extensive simulations are made on a scenario where nodes moves randomly.Results are presented as a function of a novel mobility metric designed to reflect the relative speeds of the nodes in a scenario.Furthermore, three realistic scenarios are introduced to test the protocols in more specialized contexts.In most simulations the reactive protocols (AODV and DSR) performed significantly better than DSDV.At moderate traffic load DSR performed better than AODV for all tested mobility values, while AODV performed better than DSR at higher traffic loads.The latter is caused by the source routes in DSR data packets, which increase the load on the network.routers and hosts, thus a node may forward packets between other nodes as well as run user applications.Mobile ad-hoc networks have been the focus of many recent research and development efforts.Ad-hoc packet radio networks have so far mainly concerned military applications, where a decentralized network configuration is an operative advantage or even a necessity.Networks using ad-hoc configuration concepts can be used in many military applications, ranging from interconnected wireless access points to networks of wireless devices carried by individuals, e.g., digital maps, sensors attached to the body, voice communication, etc. Combinations of wide range and short range ad-hoc networks seek to provide robust, global coverage, even during adverse operating conditions.Permission to make digital or hard copies of all or part of this work for personal or classroom use is granted without fee provided that copies are not made or distributed for profit or commercial advantage and that copies bear this notice and the full citation on the tirst page.To copy otherwise, to republish, to post on servers or to redistrihute to lists.requires prior specific permission and/or a fee.

For some time, the networking community has assumed that it is impossible to do IP routing lookups in software fast enough to support gigabit speeds. IP routing lookups must find the routing entry with the longest matching prefix, a task that has been thought to require hardware support at lookup frequencies of millions per second.We present a forwarding table data structure designed for quick routing lookups. Forwarding tables are small enough to fit in the cache of a conventional general purpose processor. With the table in cache, a 200 MHz Pentium Pro or a 333 MHz Alpha 21164 can perform a few million lookups per second. This means that it is feasible to do a full routing lookup for each IP packet at gigabit speeds without special hardware.The forwarding tables are very small, a large routing table with 40,000 routing entries can be compacted to a forwarding table of 150-160 Kbytes. A lookup typically requires less than 100 instructions on an Alpha, using eight memory references accessing a total of 14 bytes.

Wireless i~; becoming a pop•ular way to connect mobile computers to the Internet and other networks.The bandwidth of wireless links will probably always be limited d1lf to properties of the physical medium and regulatory limits on the n~;e of frcqncncies for radio communication.Therefore.it is necessary for network protocols to utilize the available bandwidth efficiently.If enders of IP packc/s arc growing and the bandwidth required for transmitting headers is increasing.With the coming of I Pvfj the addre8.ssize in creases from 4 to 16 bytes and the basic IP head a increases from 20 to 4 0 bytes.Monovcr, most mobility schemes tunnel packets addressed to mobile hosts by adding an extra JP header o1• eJ:lm routing information, typically increasing the .size of TCP/IPv4 headers to 60 bytes and TCP/!Pvfi headers to 100 bytes.In this paper, we provide new header compres~;ion schemes for UDP/IP and TCP/IP protocols.IVc show how to reduce the size of UDP /IP headers by an order of magnitude, down to four to five bytes.Our method worl.'s Ol'el' simplex links, lossy links, multi-access links, and supporls multicast communication.IVe also shou.: how to generali.~ethe mo::;l commonly used method for header compres~;ion for 'J'CP/IP!•.{, dereloped by liau Jacobson, to !Pv6 and nwltiple JP headtrs.The resulting scheme nnfortun at ely reduces TCP throughput ova los~;y link$ due to unfavorable interaction with TCP's congestion control mechanisms.However, by addin_q two•This work was supported by grants from the c..,nt.re for Dist.anceSpanning Technology (COT).Lul<!t•, Sweden, and Ericsson Radio Systems AB.