IEEE Communications Magazine

Presents the guest editorial for this issue of the publication.

Due to the increasing demands of multimedia services supporting high bit rates and mobility, ATM, TCP/IP, and satellite technology are going to be associated to form the internetwork infrastructure of future global systems. In this scenario, distinctions between terrestrial and satellite communications systems, as well as between fixed networks and 3G mobile networks, will cease to exist in a global coverage wireless system. The European Action COST252 actively participated in developing the satellite component of UMTS.

We discuss the design of a multicast event distribution service intended to support extremely large-scale event distribution. To date, event notification services have been limited in their scope due to limitations of the infrastructure. At the same time, Internet network and transport layer multicast services have seen limited deployment due to lack of user demand (with the exception of streaming services, e.g., on Sprint's US core network and in the Internet II). Research in active networks and reflective middleware suggests a way to resolve these two problems at one go. The goal of this article is to describe a reflective middleware system that integrates the network, transport, and distributed middleware services into a seamless whole. The system integrates this "low-level" technology into an event middleware system, suitable for telemetry, novel mobile network services, and other as yet unforeseen applications.

Extruded subnets is the name given to a new type of subnetworks, connected to the Internet through "wideband" residential access lines, such as asynchronous digital subscriber line (ADSL) or cable connections, but seamlessly integrated into their remote corporate network. Extruded subnets are designed to completely hide the fact that they are remote. This article presents the constraints and requirements of extruded networks, and discusses the problems and solutions of their implementation. A new solution is proposed. It is based on IPSec and Realm Specific IP protocol (RSIP), a protocol published as an RFC, mainly as an alternative to Network Address Translating (NAT). An extension is proposed to RSIP in order to improve the scalability of the solution. The use of IPSEC and the extended RSIP satisfies all the requirements for extruded subnets and enjoys excellent scalability. This extruded subnet implementation is now available as open source software.

Presents the guest editorial for this issue of the publication.

We present an overview of research activities on space-time coding for broadband wireless transmission performed at AT&T Shannon Laboratory over the past two years. The emphasis is on physical layer modem algorithms such as channel estimation, equalization, and interference cancellation. However, we also discuss the impact of space-time coding gains at the physical layer on throughput at or above the networking layer. Furthermore, we describe a flexible graphical user interface attached to our physical layer simulation engine in order to explore the performance of space-time codes under a variety of practical transmission scenarios. Simulation results for the EDGE cellular system and the 802.11 wireless LAN environment are presented.

We present an overview of the Open Services Gateway Initiative (OSGi/spl trade/) technology and its associated mechanisms for accessing devices. A technical description of work currently underway to map various industry device and service discovery protocols to OSGi is presented, followed by an illustrative usage case for a home networking environment. Finally, the authors describe the benefits OSGi discovery technology offers in home networking and discuss potential future work in this area.

The hybrid fiber coax architecture deployed by the cable service providers has been successful in capturing a substantial piece of the residential broadband access market. In the United States over five million homes connect to the Internet using DOCSIS cable modems. We describe an evolution path to enhance the HFC plant to provide, initially, Gigabit Ethernet (and eventually multi-Gigabit Ethernet) on the trunk and feeder portions, and 100 Mb/s Ethernet on the subscriber drops. This next-generation HFC network will enable cable service providers to address the vast and underserved small and medium-sized business market, as well as offer emerging applications and services to the residential market.