We describe a system, a wireless overlay on existing hybrid fiber/coax digital packet-based networks, for high-speed, short-range wireless access to video programming services, to the Internet, and to the telephone, cellular mobile, and other communication networks. Wireless access may be provided to both fixed (residential) users and to passersby with portable devices. Smart transponder nodes and antennas are densely distributed along the access cable line for wireless communication with user nodes. The antennas along a cable access line form an adaptive "superantenna" that is excited, for downstream transmission, by short sequences of vector signals that cancel radio interference. These excitations can be derived from a stable adaptive process. Upstream transmission from a subscriber node is designed so that the vector received by the superantenna can be used to separate this signal from that of other users' transmitters. Cooperation among end users is not necessary but is possible. Antenna excitation signals are controlled from the system headend, based on processing that uses measured channel parameters between the sets of access line and user antennas. A program controller in the headend, responding to end user requests, manages delivery of selected program streams and other customer services through generation of superimposed superantenna excitation signals that target multiple end users. This model offers opportunities for flexible capacity allocations and a wide range of programming and customized private.

Presents the welcome message from the conference proceedings.

This Special Issue of JCN explores architectures and implementation challenges for network elements into which executable software can be safely installed and run during normal operation. Unlike traditional network elements. that are pre-programmed by manufacturers or operators. this new type of element, which is usually but not necessarily a switch or router, can be dynamically programmed and can run multiple instances of ontrol and data processing functions. The applications of multicast, traffic control, and DiffServ implementation are addressed in this issue. Many people working in this area feel that support of multiple virtual private networks. each with its own sustomized control plane. will be an important commercial application in the future. More generally. programmable network element. encourage an open market in control and traffic-processing software. promising cost savings and imaginative new services capabi lities for the operators of future networking infrastructure.

Presents the guest editorial for this issue of the publication.

Introduction to Data Communications. Theoretical Foundations of Digital Communications. Error Correcting and Detecting Codes. Baseband Pulse Transmission. Passband Data Transmission. Synchronization. Optimum Data Transmission. Automatic and Adaptive Equalization. Echo Cancellation. Topics in Digital Communications. Index.