Telcordia Technologies

About: Telcordia Technologies is a based out in . It is known for research contribution in the topics: Network packet & Node (networking). The organization has 3097 authors who have published 4737 publications receiving 237882 citations.

Dispersion penalty analysis for LED/single-mode fiber transmission systems

Abstract: GREAT DEAL of attention has been focused recently on telecommunication systems based on single-mode fiber (SMF) and LED light sources for future deployment in the local network and subscriber loop. These systems combine the advantages of the low loss, large bandwidth, and upgrade potential of single-mode fiber with the high reliability and temperature stability, as well as the low cost of LED’s. Recent experiments have demonstrated the feasibility of LED-SMF ’ systems for transmission rates up to 560 Mbit/s and span lengths (at 140 Mbit/s) up to 50 km [1]-[lo]. Chromatic dispersion is a potential limitation at these bit rates and span lepgths, however, because of the broad spectral widths of LED’s. Even for a practical system of shorter transmission distance, the dispersion penalty remains an important consideration in the power budget since the total power coupled into single-mode fiber is relatively small for LED systems. It is thus important to have realistic estimates of dispersion penalties in LED-SMF system design. Penalties for chromatic dispersion in multimode fiber have been calculated for LED’s based on the assumptions of an optical receiver which has been re-equalized to compensate for the fiber dispersion, and an f receiver noise spectral density [ 111, [12]. In practical systems, however, these assumptions are often not applicable. In this paper we present a new calculation of dispersion penalties arising from intersymbol interference for LED-SMF systems with no re-equalization (the more commonly adopted scheme), and compare the results obtained with a treatment of the re-equalized system which considers both white, andf2 receiver noise spectral densities. Simple approximations of dispersion penalties are derived, and bitrate distance product limits are presented as a useful estimation tool for system feasibility studies. Single-mode fiber transmission experiments at 90, 140, and 560 Mbit/ s have been performed using 1.3- and 1.5-pm LED’s [3][6], and the measured dispersion penalties are compared with the results of the above analysis.

Method for cluster routing in direct link using two associated routing tables at node or signaling transfer point

Abstract: Method and apparatus for cluster routing and management of information from a remote node of a communications network to a network cluster in the presence of at least one direct linkset extending between the remote node and the cluster. The communications network includes a cluster and a plurality of nodes for communicating information to the cluster, which includes a plurality of members. The plurality of nodes includes the remote node and a node adjacent to the cluster in direct communication with the members. The method includes providing a direct linkset between the remote node and at least one of the members of the cluster so that the remote node is directly connected to the cluster, and performing cluster routing of information from the remote node to the members of the cluster not directly connected to the remote node.

Application layer mobility management scheme for wireless Internet

Abstract: This paper discusses an application layer framework that uses a set of standard IETF protocols for supporting real-time and non-real-time multimedia applications on mobile terminals of next generation wireless [3G/4G] networks. It describes a 3G-IP architecture and brings out the requirements and issues which are essential for supporting roaming users in the wireless Internet in a ubiquitous way. In addition it highlights ways of achieving endto-end mobility by means of signaling instead of using any agent in the middle of the network as often done currently.