Issue 1 • Date First Quarter 1999
Cited by: Papers (7) | Patents (1)
Several government- and industry-funded prototyping and development activities in WDM optical networks are being conducted at various R&D centers. Optical networks can be deployed on top of an existing physical fiber plant that can provide a transparent all-optical signal path to its upper layer, thereby providing broadband services. For instance, an all-optical layer between the physical and ATM layers in a B-ISDN network will significantly improve both efficiency and flexibility for the provision of broadband services. One attractive feature of optical networks is the ease of its logical reconfigurability, i.e., any desired logical network topology can be embedded on top of any given physical fiber plant, subject to the limitations on the number of available wavelengths and transceivers. The logical topologies can be broadly classified into two categories: arbitrary and regular. Nodal connectivity patterns in regular topologies are very systematic and well defined, which simplifies routing and management operations. However, it is difficult to add an arbitrary number of nodes to a regular topology and still maintain its well-defined structure. Over the past few years, several regular logical topologies have been proposed for optical networks. In this article we provide brief descriptions of these regular logical network topologies and a comparative study of their various performance metrics, e.g., average hop distance (viz. network utilization), routing, fault tolerance, and scalability. View full abstract»
Cited by: Papers (22) | Patents (2)
Bidirectional cable TV networks using hybrid fiber coaxial (HFC) systems are good examples of broadcast environments where a contention resolution algorithm is needed in order to allocate the multiaccess medium (in this case the upstream link) among the various nodes. Recent activities of the IEEE 802.14 working group aimed at defining the physical and medium access control (MAC) layer protocols for HFC cable networks have focused on the study and evaluation of several contention resolution solutions for inclusion in the MAC protocol specifications. In this article several contention resolution algorithms considered by the IEEE 802.14 group are reviewed. Different implementations for several well known contention resolution algorithms such as tree-based and p-persistence are presented. Their performance is evaluated in the HFC context with respect to upstream channel allocation, roundtrip delay, various traffic types, and number of stations in the network. Simulation results for configurations and scenarios of interest are also presented. View full abstract»
Cited by: Papers (36) | Patents (10)
Active networks represent a new approach to network architecture. Routers can perform computations on user data, while packets can carry programs to be executed on routers and possibly change their state. Currently, the research community is divided concerning the usefulness of active networks. On the one hand, active networks provide a much more flexible network infrastructure, with increased capabilities. On the other hand, they are obviously more complex than traditional networks and raise considerable security issues. The purpose of this article is to provide a broad survey on active networks. The first goal is to highlight their efficiency in a variety of applications. After presenting some key points on each application, we discuss some current experimental technologies and assess the usefulness of active networks in congestion control, multicasting, caching, and network management. The second goal is to address the security issues that active networks raise: the problem is defined, and techniques for solving it are presented and elaborated upon with a description of a specific implementation of a secure environment and related performance measures. Issues related to the design of a programming language for active networks are also discussed. The third goal is to classify active network architectures based on their design approach. Thus an inclusive presentation of currently proposed architectures, which focuses on their design attributes, capabilities, performance, and security, is given. View full abstract»
Cited by: Papers (15) | Patents (2)
An overview is given of previously-proposed measurement-based connection admission control (CAC) methods. First we address requirements for CAC methods, and then provide a taxonomy for CAC methods. Measurement-based CAC methods are discussed in detail, classified according to the taxonomy, and compared against each other with respect to the requirements. We conclude that measurement-based CAC methods based on effective bandwidth and bufferless models are promising because they do not require complex hardware and are less dependent on assumptions regarding traffic than methods in which the effect of buffer is considered. View full abstract»
Aims & Scope
IEEE Communications Surveys & Tutorials is an online journal published by the IEEE Communications Society for tutorials and surveys covering all aspects of the communications field. Telecommunications technology is progressing at a rapid pace, and the IEEE Communications Society is committed to providing researchers and other professionals the information and tools to stay abreast.
Meet Our Editors
Ekram Hossain, Ph.D., P.Eng.
University of Manitoba