| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 126-133 |
| Abstraksi Narasi | : | The authors present an overview of new multiple access schemes based on a combination of code division and multicarrier techniques, such as multicarrier code-division multiple access (MC-CDMA), multicarrier direct sequence CDMA (multicarrier DS-CDMA), and multitone CDMA (MT-CDMA). |
| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 44-53 |
| Abstraksi Narasi | : | The ATLANTA switching architecture described in this article has the following distinguishing characteristics: 1) is nonblocking, 2) scales modularly over a wide range of switching and buffering capacities using commonly available implementation technology, 3) achieves high buffer utilization while using distributed buffers, 4) has low complexity, and 5) provides a clear path for future growth in featues. The ATLANTA architecture uses an innovative structure with ingress and egress buffers, where selective backpressure is applied from the fabric to the ingress cards. Selective backpressure makes the buffers in the ingress cards act as an extension of the output buffers in the fabric, achieving `sharing` of the distributed buffers and buffer utilization comparable with a centralized shared-memory switch. The advantage is that the majority of the buffers are in the ingress and egress port cards, and are implemented using low-cost off-the shelf memories regardless of the total switching capacity. Different arrangements are possible for the switch fabric. In the smallest configuration, the fabric consists of a single standalone switching module; for larger switching capacities, the fabric is a modular three-stage memory/space/memory (MSM) arrangement. The ATLANTA architecture provides optimal support of multicast traffic. The ATLANTA chipset provides the complete set of building blocks for implementing ATM switches ranging in capacity from 622 Mb/s to 25Gb/s. The chipset consists of four chips, two devices to be used in the fabric and two in the port cards. The port devices provides full-duplex ingress and egress functionality at 622 Mb/s port rate (plus the overhead due to the local header used internally to the switch). The physical interface to the incoming/outgoing lines supports the UTOPIA II multiplexing standard, and the port devices manage multiplexing/demultiplexing from/to a maximum of 30 subports per port. Although our current implementation of the architecture is targeted primarily to ATM, the principles behind the architecture are more general, apply to IP switching and routing technologies. |
| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 54-68 |
| Abstraksi Narasi | : | Providing quality-of-service quarantees in both cell- and packet-based network requires the use of a scheduling algorithm in the switches and network interfaces. These algorithms need to be implemented in hardware in a high-speed switch. In this article the authors present a number of approaches to impelement scheduling algorithms in hardware. The authors begin by presenting a general methodology for the design of timestamp-based fair queuing algorithms that provide the same bounds on end-to-end delay and fairness as those of Weighted Fair Queuing, yet have efficient hardware implementations. Based on this general methodology, the authors describe two specific algorithms, Frame-Based Fair Queuing and Starting Potential-Based Fair Queuing, and discuss illustrative implementations in hardware. These algorithms may be used in both cell switches and packet switches with variable-size packets. A methodology for combining a traffic shaper with this class of fair queuing schedulers is also presented for use in network interface devices, such as an ATM segmentation and reassembly device. |
| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 72-77 |
| Abstraksi Narasi | : | This article presents a new systematic approach to network evolution, considering access and core network evolution as a whole. The evolution phases are designed to fulfill the following evolution requirements. Each phase provides an incentive to the operator and the customer by providing more functionality, higher bit rates, or reduced cost. The phases are realistic for low penetration and match the growth of infrastructure to the gradual growth of the demand. Technologies are independently introduced in the access and core networks depending on demand. The evolution scenario starts with ADSL and evolves toward ultra-broadband access networks based on SuperPON architectures. The new Enhanced APON architecture is introduced as a practical intermediate evolution phase. For the first time, the principle of segmentation is applied to APONs/SuperPoNs to enable gradual in number of subscribers and network capacity. Optical channels and wavelength-division multiplexing are introduced in the core network. |
| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 22-35 |
| Abstraksi Narasi | : | Contemporary wireless communications are based on digital communications technologies. The recent commercial success of mobile cellular communications has enabled in part successful designs of digital signal processor with appropriate on-chip memories and specialized accelerators for digital transceiver operations. This article provides an overview of fixed point signal processors and ways in which they are used in cellular communications. Directions for future wireless-focused DSP technology developments are discussed. |
| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 88-93 |
| Abstraksi Narasi | : | There is a worldwide effort to define a full-service access network. The Broadbandloop project was formed by a European consortium funded by the European Union with the objective of defining a strategy for evolution from a narrowband voice and data network to a broadband network. The project is defining a system concept based on new innovative PON technology, which enables fiber to cost effectively penetrate close to the customer, and VDSL technology for transmission over twisted copper pairs. The system concept is validated in field trials in Denmark, Portugal, and Poland. The article describes the different requirements for a full-service access network, the system concept, and technologies developed. Result from modeling of broadband traffic and the corresponding bandwidth are given. The cost effectiveness of using new fiber vs. reusing existing telephone copper plants has been evaluated, and results from these studies are presented. |
| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 116-124 |
| Abstraksi Narasi | : | Three challenges for deploying services are the time-consuming process of service creation, the interoperability over heterogeneous platforms, and the gap between the needs of service management and the functionalities of network management. In this article we describe a methodology to attack the first two challenges, namely, to simplify the process of service creation and provide a platform-independent framework for service operations. A set of broadband service-independent building blocks (SIBs) are designed and used to create and customize SIB graphs for broadband services. During service running time, the service agent interprets a SIB graph and executes SIB procedures which are all downloaded from the service provider. Web, Java, and CORBA are the technological elements of this methodology. Two examples, video conferencing and video on demand, are given to demonstrate the feasibility of this approach. |
| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 78-87 |
| Abstraksi Narasi | : | This article analyzes options for transporting CATV distribution, pay-per-view, and video-on-demand over a residential broadband network. It provides clearly tabulated evaluations of video coding alternatives, ATM service category alternatives, ATM adaption layer alternatives, and methods for dealing with errors and delay. Conslusions are drawn regarding buffer requirements, congestion control, and error control. |
| Nama Pengarang | : | Bernard Sklar, David J. Wright, Ying-Dar Lin et al, Niels Engell Andersen et al, Zoran Kostic, Selvaraj Seetharaman, M. Oskar van Deventer et al, Anujan Varma, Dimitrios Stiliadis, Fabio M. Chiussi, Joseph G. Kneuer, Vijay P. Kumar, Shinsuke Hara, Prasad, Ramjee , Razavi, Behzad, Patrick R. Trischitta, Antonio Jose Garcia Medina, Roberto Cofre Remedi, Ali N. Akansu et al |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 94-101 |
| Abstraksi Narasi | : | The goal of this article is to describe the main ideas the new class of codes called turbo codes, whose performance in terms of bit error probability has been shown to be very close to the Shannon limit. In this article, the mathematical measures of a posteriori probability and likelihood are reviewed, and the benefits of turbo codes are explained in this context. Since the algorithms needed to implement the decoders have been well documented by others, they are only referenced here, not described in detail. A numerical example, using a simple concatenated coding scheme, provides a vehicle for illustrating how error performance can be improvrd when soft outputs from the decoders are used in an iterative decoding process. |
| Nama Pengarang | : | - |
| Nama Majalah/Jurnal | : | IEEE Communications Magazine |
| Volume / Nomor Edisi | : | - |
| Nomor Halaman | : | 34-40 |
| Abstraksi Narasi | : | An overview of the current status of wideband wireless local access technologies is provided. Service scenarios and availability of the market and products for wireless LAN and wireless ATM technologies are discussed. Similarities among IEEE 802.11 and HIPERLAN standards for wireless LANs and the developing prototypes for wireless ATM are evaluated. An update on the status of the available unlicensed bands in the United States as well as status of the wideband projects in the European Community and Japan is presented. |
Unduh Dokumen Berkas PDF Utama