Ad-hoc Networks have been proposed for a variety of applications where support for real time, multimedia services may be necessary. In order to operate ad hoc networks several protocols, for media access control, power control, routing, and transport are needed. We take a holistic approach to the problems in ad hoc networks. We start by postulating general design principles for power control based on the effect of transmit power on various performance metrics. These are used to design a set of protocols which attempt to optimize different performance metrics, as all the metrics cannot be simultaneously optimized in general. Some of these protocols have been implemented in the Linux kernel in an architecturally appropriate manner. Extensive testing was not possible due to the limitations of the current generation of hardware, and so performance results obtained through NS2 simulations are used to illustrate the potential benefits of the power control protocols. Our work at the routing layer is motivated by the difficulty in implementing on-demand routing protocols for ad hoc networks in common operating systems. It provides an API and its implementation in Linux as a user-space library (ASL), which facilitates implementation of on-demand routing protocols. It has been used to implement a few routing protocols.