Novel algorithm for time division multiple access in broadband ISDN passive optical networks

For shared access to a broadband communication network using the asynchronous transfer mode (ATM) a passive optical network (PON) has previously been proposed. A novel algorithm to evaluate the time division multiple access (TDMA) protocol which controls the traffic from the various subscribers towards the shared access equipment (upstream direction) is proposed. It uses counters to estimate the moment of a data packet arrival at the subscriber side. By this ‘look-ahead’ technique no extra upstream channels are needed to initiate the polling by the subscriber. The algorithm guarantees fair access for all subscribers and minimizes the necessary overhead. Both the maximum access delay and overhead may be readily calculated, and the obtained results were supported by numerical simulation. Applicability in the standard broadband network environment has been proved by hardware design simulation.     

PON with Automatic Protection switching for high reliable communication

PON (Passive Optical Network) permits the economical deployment of FTTH (Fiber to the Home) networks by sharing a single optical subscriber line among multiple subscribers. Especially since 2002, the deployment of PON systems has grown rapidly. This paper introduces the current status of FTTH in Japan then proposes a redundant optical access system with APS (Automatic Protection Switching) over PON which enables PONs for FTTBus (Fiber to the Business).     

Design Philosophy and Hardware Implementation for Digital Subscriber Loops

This paper presents various requirements and configurations in the information network system (INS) NTT's version of the integrated services digital network (ISDN)- such as field trials, and technologies and equipment design of the digital subscriber loop using balanced wire pairs. The main aspects characterizing digital subscriber loops, are a customer access structure, a digital transmission system on existing subscriber loops, and customer interface. A configuration of two-wire digital subscriber loops with two customer access channels, which is adopted in the field trials, will be described. The time-shared two-wire digital transmission and power feeding methods on subscriber loops are discussed. The common mode rejection ratio (CMRR) is discussed in detail, since CMRR is one of the main factors which affects the transmission ability of balanced wire pairs. A proposed self-clocked four-wire customer interface utilizes time division multiplexing technique. The digital subscriber loop operates on a call-by-call basis for link establishment to avoid excessive power dissipations as well as to avoid impairments caused by crosstalk from other lines within a cable. Its design objectives and implementation are also discussed.     

Evolutionary architecture for an all-services ATM access network

This paper presents a flexible concept for a broadband subscriber access network which minimizes investment costs by predominantly using the existing network infrastructure. The target network may consist of either a coaxial tree-and-branch structure or symmetrical copper pairs to the subscriber, and is connected to the central head station with the aid of optical feeder lines which can be implemented or enhanced by a passive optical network (PON). In the event of an increase in bit rate requirements, the coaxial network can be expanded by dividing it into smaller, optically fed subnetworks or by supplementing it with optical overlay systems. Flexibility, expandability and low costs are achieved through the standard ATM format implemented for the signals of all interactive services down to the network termination units on the subscriber side. Those signals are transmitted in the coaxial network in frequency bands above the CATV band in accordance with a multiple of the CATV channel width to ensure that the modulation and demodulation is implemented in a cost-efficient manner while providing ‘bit rate on demand’ for a suitably high number of subscribers. Separation of the network termination unit from the customer premises equipment enables a flexible, cost-efficient subscriber configuration to be selected, existing domestic wiring to be used and several completely different subscriber terminals to be simultaneously connected.     

Low‐Cost,Low‐Power,High‐Capacity 3R OEO‐Type Reach Extender for a Long‐Reach TDMA‐PON

This paper proposes a low‐cost, low‐power, and high‐capacity optical‐electrical‐optical‐type reach extender that can provide 3R frame regeneration and remote management to increase the reach and split ratio with no change to a legacy time division multiple access passive optical network. To provide remote management, the extender gathers information regarding optical transceivers and link status per port and then transmits to a service provider using a simple network management protocol agent. The extender can also apply to an Ethernet passive optical network (E‐PON) or a gigabit‐capable PON (G‐PON) by remote control. In a G‐PON, in particular, it can provide burst mode signal retiming and burst‐to‐continuous mode conversion at the upstream path through a G‐PON transmission convergence frame adaptor. Our proposed reach extender is based on the quad‐port architecture for cost‐effective design and can accommodate both the physical reach of 60 km and the 512 split ratios in a G‐PON and the physical reach of 80 km and the 256 split ratios in an E‐PON.     

Implementation of a broadband integrated services hybrid network

The issues involved in the design of a broadband integrated services digital network (B-ISDN), that utilizes optical fibers in the subscriber loop, are considered. A hybrid scheme that provides integrated access to ISDN and broadband services by delivering voice/data signals in a digital format while using an analog format for full-motion video services to subscribers is proposed. The discussion covers planning for a B-ISDN, the system concept, implementation, the loop fiber network, subscriber equipment, and cost comparison and analysis     

Feasibility of a 1 Gbit/s/ 565 Mbit/s bidirectional single-mode-fibre subscriber line for B-ISDN using 1279 nm/ 1315 nm wavelength division multiplexing

A laboratory system, transmitting 1 Gbit/s signals to a subscriber station and 565 Mbit/s signals back to a head station via one 20 km-long single-mode fibre, has been realised. Wavelength division multiplexing via two 3 dB fibre couplers of selectivity ?0.04 dB/nm has been used. The experiment demonstrates that bidirectional single-mode-fibre transmission is applicable to a future B-ISDN subscriber network.     

The wireless art and the wired force of subscriber access

Different technologies for subscriber access are put side by side. Starting from the various transmission media characteristics of all systems, the well-known twisted pair lines with their corresponding digital subscriber line services are evaluated against wireless local loops, communications over ubiquitous power lines, high-bandwidth cable modems, and mobile radio. Each technology has its advantages and disadvantages. The different technologies will find their fields of applications. Most networks will have to provide a mixture of solutions for individual subscribers and customer segments to meet their boundary conditions. As a result, the future of subscriber access is a hybrid solution     

发展光接入网的新途径

简述通信接入网的发展概况,指出现代通信网的用户接入网部分正在从原来的无源光网络向超级无源光网络(superPON)发展,它将真正实现光纤连至每个家庭,而且将显著加大接入的带宽能力、数字信息速率和延长传输距离范围。用户家庭不再需要中间站的接入节点(AN),而是经过光纤放大器直接连至核心网中的AN。文中具体叙述superPON的结构、主要技术和协议,包括光放大器、光突发接收机和媒体接入控制(MAC)协议,并讨论降低成本的可能性和未来演进。     

Error correction performance in digital subscriber looptransmission systems

The author describes an error correction system for digital subscriber loop transmission systems which use time compression multiplexing (TCM). An interleaved block code is used to correct the burst errors due to impulse noise from analog telephone circuits. This interleaving method requires no extra hardware and contributes no additional delay. To evaluate the transmission performance of this error correction system, the bit error rate after decoding is derived on the basis of a burst error model for 200 kb/s digital subscriber transmission using the alternate mark inversion (AMI) line code. The experimental results for a 200 kb/s TCM system show that burst errors are substantially reduced     

Simulation and experimental studies on the concept of arate-adaptive digital subscriber loop (RA-DSL)

The authors report simulation results and prototype control protocols for a digital subscriber loop transmission system, which will find and operate at the highest common bidirectional transmission rate that is viable on a given loop while preserving a specified noise margin. A prototype implements the rate-adaptation and transmission protocols over a captive multigauge cable facility. Simulation results predict the accompanying symbol rate versus reach characteristics for a transceiver with the same structure as basic rate access (BRA) systems under RA-DSL control. Results show that 1.5 Mb/s could be delivered to loops of up to 2 km while subscribers out to 10 km could receive 80 kb/s. For a number of specialized or short-notice situations, RA-DSL could be the basis for a fast and flexible response vehicle. If RA-DSL cannot serve an individual combination of distance and capacity, existing methods remain. However, a statistical assessment with metro population data shows the potential for RA-DSL to satisfy 4-6 times more n×DS-0 access requests than BRA on existing copper, without carrier serving area constraints     

Time-Shared Two-Wire Digital Subscriber Transmission System and Its Application to the Digital Telephone Set

Adopting digital techniques in the local network area will enhance the possibility of extending digital operation capability to the subscriber's equipment. The problem is to convey digital signals at a bit rate of at least 64 kbits/s in both directions over existing two-wire subscriber loops. This paper describes a time-shared two-wire digital subscriber transmission system in which the directional separation of two signals (GO and RETURN) is accomplished by the time division bidirectional transmission method in burst-mode, and also reports results of investigations on the feasibility of an all digital telephone subscriber loop system.     

Performance Evalution of 2B1Q Data Echo Canceller in Digital Subscriber Access Networks

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Channel Enlargement of PON System Using Nonreciprocal Multiplexing Filter Based on CWDM

We propose a nonreciprocal filter based on coarse wavelength division multiplexing (CWDM) that reduces the upstream channel insertion loss in a passive optical network (PON). We also propose a method to increase the number of channels/optical network units (ONUs) in PON systems using the proposed filter to reduce the service cost per subscriber. Experimental results show that the PON system with the proposed 4‐channel filter can reduce the power budget of the upstream and increase the number of ONUs by 3 to 4 times that of a conventional time‐division multiplexing PON.     

Broadband access using subcarrier multiplexing and asymmetric digital subscriber lines

A broadband access system using subcarrier multiplexing on optical fibre and asymmetric digital subscriber lines (ADSL) or very high‐speed digital subscriber lines (VDSL) on unshielded twisted‐pair is proposed to provide broadband access. In this hybrid‐fibre/twisted‐pair (HFTP) system, the digital multiplexing/demultiplexing process is moved back to the central office by using subcarrier multiplexing for fibre transmission. Instead of installing in remote node, ADSL/VDSL transceivers are installed at the central office to greatly reduce the remote node complexity. The local node simply down‐converts the subcarrier multiplexed ADSL/VDSL signal to the baseband, suitable to send directly into the twisted‐pair. The reduction of complexity could result in a lower initial installation cost, especially for a low service penetration rate. Copyright © 2000 John Wiley & Sons, Ltd.     

Upgrade of passive optical subscriber network

An upgrade method is described for a two-way broadband service transmission of a previously proposed passive optical subscriber network (PASS-NET) PASS-NET uses optical frequency division multiplex/time-division multiplex (OFDM/TDM) techniques for downstream transmission and time division multiple access (TDMA) for upstream. Fundamental experiments for downstream transmission to two subscribers are executed to demonstrate the possibility of the upgrade method. Two wavelengths emitted by a distributed Bragg reflector-laser diode (DBR-LD) tunable laser with a 5-GHz (0.04-nm) space between them are directly intensity modulated at 32 Mb/s. Each wave transmits narrowband service to each subscriber. The third wavelength emitted by another DBR-LD tunable laser with an 11-nm separation from the two wavelengths is directly intensity modulated at 100 Mb/s and overlaid     

基于ATM的无源光接入网中ONT的设计考虑

介绍了 ATM- PON系统中的 ONT的概念及其核心功能 ,分析了 ONT与 PON和用户端的接口。结合协议模型解释了各层的主要功能 ,并给出了 ONT的结构框图及其 PON传输子层的实现框图。     

Low-current 1.3 ?m edge-emitting LED for single-mode-fibre subscriber loop applications

Index-guided InGaAsP edge-emitting LEDs couple 7 ?W into single-mode fibre at a drive current of only 20 mA. These devices can be modulated at data rates in excess of 432 Mbit/s, and their operating characteristics are ideal for single-mode-fibre subscriber loop applications.     

全业务网APON光纤接入传输系统

介绍在国家八六三计划资助下研制成功的全业务网接入传输系统 ,首先简述了系统构成、用户业务接口和传输帧结构 ,接着对 HFC双向光纤传输系统进行了简介 ,最后介绍了 ATM- PON系统和HFC系统的性能指标     

ATM-PON系统的突发同步技术

在采用ＴＤＭＡ协议的无源光网络中,突发同步是一项关键技术,一般采用基于多相对钏的关键字检测法。本文提出了一种新颖的基于数据地的突发同步技术,采用了高速ＦＰ－ＧＡ和ＥＣＬ有源延时器的方式实现１５５Ｍｂｉｔ／ｓ突发同步器。由于膝用同一主时钏对数据抽样,不需要进行相位校准,简化了电路的设计;相对于传统的ＡＳＩＣ设计方案,该 开发成本低、开发周期短的优点。