On Nonblocking Multiconnection Networks

In the paper, four theorems describing conditions under which a three-stage multiconnection network is nonblocking for different routing strategies are formulated and proved. These theorems hold for any values of the structural parameters of a network. For some networks having a small number of outer stage switches, these theorems give significantly lower numbers of required middle stage switches than theorems currently known.     

Rearrangeability of multicast Clos networks with middle-stage fan-out

The sufficient and necessary conditions under which a three-stage Clos network is rearrangeable for multicast connections are given. It is assumed that only switches of the middle stage have the fan-out property. Such an assumption is valid for some practical switching systems, e.g., high-speed crossconnects.     

Optical networks—the electro-optic reality

A general overview of the current status and future trends in optical networking is given. Special attention is given to the coexistence of optical and electronic technologies in telecommunications networks. After reviewing the advantages of both technologies, their use in different network areas is discussed. A critical survey of current and new transport technologies in optical core and metropolitan networks is given, including SDH/SONET and its enhancements, OTN, RPR, and Ethernet. The current status and prospects for photonic switching are briefly presented. The paper is concluded with an overview of the control plane for optical transport networks.     

Novel type of switching network composed of digital switching matrices

A new type of one-stage switching network comprising digital switching matrices is proposed. In many cases such a network contains fewer matrices than currently known networks. The proposed one-stage networks can be used as submodules for cost-effective multistage networks.<>     

Quality of resilience as a network reliability characterization tool

With the increased role of resilience in modern networks, the existing quality of service is required to be expanded with service availability and maintainability. Recently, studies have shown the strong limitation of the common availability metrics for measuring the user?s quality of experience. In this article a joint specification of QoS definitions with a sophisticated service resilience characterization is proposed, and a concept called quality of resilience is defined. In this unified performance metric, the frequency and length of service interruption are evaluated. It can be used as a tool for characterization of network reliability, as well as comparison and selection of recovery methods. Additionally, by including it in service level agreements, new and more complex requirements of commercial applications can be guaranteed.     

New structure for digital switching network

Methods for the design of cost-effective one-stage PCM switching networks composed of digital switching matrices are proposed. These one-stage networks have, in many cases, a more regular structure and contain fewer elements than networks currently known. The proposed one-stage networks can also be used as submodules for multistage networks.<>     

Cost-effective digital switching network

A method for the design of cost-effective one-stage PCM switching networks composed of uniform time-space elements is proposed. These one-stage networks can be used as submodules for multistage networks, having, in many cases, fewer elements than currently known networks.     

Rearrangeable one-sided switching networks composed of uniform time-space elements

One-sided rearrangeable switching networks composed of uniform time-space elements are considered. Two theorems presenting conditions under which two- and four-wire networks are rearrangeable are given and proven. These theorems are also applicable for multiple-linkage space-division switching networks.