Scott Nettles

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Many important applications must run continuously and without interruption, and yet also must be changed to fix bugs or upgrade functionality. No prior general-purpose methodology for dynamic updating achieves a practical balance between flexibility, robustness, low overhead, ease of use, and low cost.We present an approach for C-like languages that(More)
PLAN (Packet Language for Active Networks) is a new language for programs that form the packets of a programmable network. These programs replace the packet headers (which can be viewed as very rudimentary programs) used in current networks. As such, PLAN programs are lightweight and of restricted functionality. These limitations are mitigated by allowing(More)
The evolutionary history of a set of species is represented by a phylogenetic tree, which is a rooted, leaf-labeled tree, where internal nodes represent ancestral species and the leaves represent modern day species. Accurate (or even boundedly inaccurate) topology reconstructions of large and divergent trees from realistic length sequences have long been(More)
D. Scott Alexander, William A. Arbaugh, Michael W. Hicks, Pankaj Kakkar, Angelos D. Keromytis, Jonathan T. Moore, Carl A. Gunter, Scott M. Nettles, and Jonathan M. Smith University of Pennsylvania July 7, 1998 Abstract Active networks must balance the exibility of a programmable network infrastructure against the safety and security requirements inherent in(More)
We present PLANet: an active network architecture and implementation. In addition to a standard suite of Internet-like services, PLANet has two key programmability features: 1. all packets contain programs 2. router functionality may be extended dynamically Packet programs are written in our special purpose programming language PLAN, the Packet Language for(More)
PLAN (Programming Language for Active Networks) is a new language for programs that are carried in the packets of a programmable network. PLAN programs replace the packet headers (which can be viewed as`dumb' programs) used in current networks. As a header replacement, PLAN programs must be lightweight and of limited functionality. These limitations are(More)
This paper presents a new MAC protocol, Mitigating Interference using Multiple Antennas with Antenna Selection (MIMA/AS-MAC), which uses multiple antennas to mitigate both interference from neighboring transmitters and fading. The proposed MIMA/AS-MAC protocol employs spatial multiplexing with antenna subset selection for data packet transmission, while(More)
We have implemented the first copying garbage collector that permits continuous unimpeded mutator access to the original objects during copying. The garbage collector incrementally replicates all accessible objects and uses a mutation log to bring the replicas up-to-date with changes made by the mutator. An experimental implementation demonstrates that the(More)