Browsing by Author "Dube, Rohit"
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Item A Comparison of the Memory Management sub-systems in FreeBSD and Linux(1998-11-18) Dube, RohitIn this article we seek to compare the memory management sub-systems of two popular and freely available operating systems - FreeBSD and Linux. First a framework is developed, spelling out the components of a generic and modern memory management system. The framework is then used in a design level comparison of memory management in the two operating systems. (Also cross-referenced as UMIACS-TR-98-45)Item Improving NFS Performance over Wireless Links(1998-10-15) Dube, Rohit; Rais, Cynthia D.; Tripathi, Satish K.NFS is a widely used remote file access protocol that has been tuned to perform well on traditional LANs which exhibit low error rates. Users migrating to mobile-hosts would like to continue to use NFS for remote file accesses. However, low bandwidth and high error-rates degrade performance on mobile-hosts using wireless links thus hindering the use of NFS. In this paper, we present two mechanisms to improve NFS performance over wireless links : an aggressive NFS client and link-level retransmissions. Our experiments show that these mechanisms improve throughput by up to 200%, which brings the performance to within 5% of that obtained in zero error conditions. (Also cross-referenced as UMIACS-TR-95-126)Item Reducing Router-Crossings in a Mobile Intranet(1998-10-15) Dube, Rohit; Korpeoglu, Ibrahim; Tripathi, Satish K.Current general purpose mobility solutions like Mobile-IP involve multiple router-crossings even when the mobile host moves within an intranet from one subnet of a router to another. An environment consisting of a large number of mobile hosts would congest the router causing hosts to experience high latency and jitter. This paper presents a mechanism to eliminate multiple router-crossings in a mobile intranet, which reduces the load on the routers and the hand-off and data latency at the mobile hosts. (Also cross-referenced as UMIACS-TR-97-01)Item Signal Stability based Adaptive Routing (SSA) for Ad-Hoc Mobile Networks(1998-10-15) Dube, Rohit; Rais, Cynthia D.; Wang, Kuang-Yeh; Tripathi, Satish K.Unlike static networks, ad-hoc networks have no spatial hierarchy and suffer from frequent link failures which prevent mobile hosts from using traditional routing schemes. Under these conditions, mobile hosts must find routes to destinations without the use of designated routers and also must dynamically adapt the routes to the current link conditions. This paper proposes a distributed adaptive routing protocol for finding and maintaining stable routes based on signal strength and location stability in an ad-hoc network and presents an architecture for its implementation. (Also cross-referenced as UMIACS-TR-96-34)