, calibrations and the expensive trimming techniques to produce upto 14-bit accu-racy at a very high speed segmented current-steering DACs. This work describes an alternative approach to design a low cost DAC IP core suitable for truely System-on-Chip application usign standard CMOS process. The architecture

1. Networking trends 2. QoS over data networks 3. Label switching 4. Gigabit, 10 Gb Ethernet, RPR 5. Storage area networks 6. IP over DWDM 7. Wireless 8. Voice over IP

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Abstract: Mobile ad hoc networks (MANETs) and wireless sensor networks (WSNs) are two recently-developed technologies that uniquely function without xed infrastructure support, and sense at scales, resolutions, and durations previously not possible. While both offer great potential in many applications, developing software for these types of networks is extremely dffcult, preventing their wide-spread use. Three primary challenges are (1) the high level of dynamics within the network in terms of changing wireless links and node hardware con gurations, (2) the wide variety of hardware present in these networks, and (3) the extremely limited computational and energy resources available. Until now, the burden of handling these issues was put on the software application developer. This dissertation presents three novel programming models and middleware systems that address these challenges: Limone, Agilla, and Servilla. Limone reliably handles high levels of dynamics within MANETs. It does this through lightweight coordination primitives that make minimal assumptions about network connectivity. Agilla enables self-adaptive WSN applications via the integration of mobile agent and tuple space programming models, which is critical given the continuously changing network. It is the rst system to successfully demonstrate the feasibility of using mobile agents and tuple spaces within