Local Loop Applications Research Articles

A comparative evaluation of DECT, PACS, and PHS standards for wireless local loop applications

In a comparative analysis the performance and capacity of DECT, PACS, and PHS for wireless local loop applications have been investigated. This article reports the results of both qualitative and quantitative analyses. The qualitative evaluation consists of a detailed comparison of the parameters of each standard and their relevance in WLL applications. In the quantitative analysis detailed simulations were performed covering diverse sets of conditions. The results of both types of analysis are presented. A major conclusion is that all three standards provide satisfactory performance for WLL applications. For low traffic environments PACS, which can employ larger cells, performs better than the other two standards. In suburban areas where, in addition to coverage capabilities, capacity is an issue, DECT has better performance. For high traffic density urban areas with great capacity requirements, the three standards all have good performance.

A comparative evaluation of DECT, PACS, and PHS standards for wireless local loop applications

In a comparative analysis the performance and capacity of DECT, PACS, and PHS for WLL applications have been investigated. This article reports the results of both qualitative and quantitative analysis. The qualitative evaluation consists of a detailed comparison of the parameters of each standard and their relevance in WLL applications. In the quantitative analysis detailed simulations have been performed covering diversified sets of conditions. The results of both types of analysis are presented. A major conclusion is that all three standards provide satisfactory performance for WLL applications. For low-traffic environments PACS, which can employ larger cells, performs better than the other two standards. In suburban areas where, in addition to coverage, capacity is an issue, DECT has better performance. For high-traffic-density urban areas with great capacity requirements all three standards have good performance.

Low power consumption and low phase noise 2.4 GHzVCOusing SiGe HBT for WLL application

Using an RPCVD-grown SiGe-base HBT and a resonator consisting of a chip varactor and a microstrip line inductor, a 2.4 GHz VCO with a power dissipation of 28 mW and phase noise of –110 dBc/Hz (at 1 MHz off carrier) has been fabricated for wireless local loop (WLL) application.

Low-tier wireless local loop radio systems. I. Introduction

The article provides the results of a set of analyses conducted to compare two major radio technologies, DECT/PWT-E and PACS, for their suitability in the local loop in the United States to provide voice and data services. DECT, digital enhanced cordless telecommunications, is a radio interface standard developed in Europe mainly for indoor wireless applications and being promoted lately for wireless local loop applications as well. PWT, personal wireless telecommunications, is a DECT-based standard developed by the TIA in the United States for the unlicensed PCS applications. PWT-E, enhanced, is the version that is suitable for the licensed PCS applications. PACS, personal access communications systems, is a total system standard (i.e. radio interface and associated network infrastructures) developed in the United States for licensed PCS applications. (PACS-UA and PACS-UB are the standards for the unlicensed PCS applications.) For the wireless local loop (WLL), we make an assumption that the radio technologies operating in the licensed PCS spectrum are more suitable to provide a quality of service that is expected traditionally from a local exchange company (LEC). Therefore, this article focuses on the PACS and PWT-E, rather than PACS-UB and PWT. Also note that the article focuses on the North American version, PWT-E, rather than the European version, DECT. It provides an introduction to the PACS and PWT technologies.

PACS: Personal Access Communications System-a tutorial

The Personal Access Communications System (PACS) is an American National Standards Institute common air interface standard developed for the 1.9 GHz PCS band in the United States. PACS uses frequency division duplexing technology and is optimized to support low-mobility pedestrian outdoor usage and wireless local loop applications in a medium-range environment. PACS-Unlicensed B (PACS-UB) is a version of PACS using time division duplexing. PACS-UB has been optimized for private, indoor wireless PBX applications and cordless telephony. Both modes of operation are supported using the same portable hardware and the same signaling protocol.

PACS: personal access communications systems an alternative technology for PCS

The personal access communications system (PACS) is an American National Standards Institute common air interface standard developed for the 1.9 GHz PCS band in the United States. The PACS uses frequency division duplexing technology and is optimized to support low-mobility pedestrian outdoor usage and wireless local loop applications in a medium-range environment. PACS-Unlicensed B (PACS-UB) is a version of PACS using time division duplexing. The PACS-UB has been optimized for private, indoor wireless PBX applications and cordless telephony. Both modes of operation are supported using the same portable hardware and the same signaling protocol.

Optical networks for local loop applications

Some of the options for optical technology within the local loop environment are examined. In particular, passive shared access networks have been considered in some detail. These networks show great promise for delivering existing telephone services to small to medium business customers (4-30 lines) economically by the early 1990s. Extending fiber to the home will also be possible by virtue of a similar passive network infrastructure for customers requiring new broadband services beyond the single telephone line. For one-line plain old telephone service (POTS) customers, an intermediate approach of terminating the fiber network at the final network distribution point, with copper retained for the final leg, may be used prior to the provision of broadband services. A key feature of the passive optical network architecture is the use of wavelength-division multiplexing (WDM) as an upgrade strategy, allowing graceful upgrading from telephone services to multichannel high-definition television (HDTV) on gigabit/second bearers and full two-way switched broadband services employing wavelength routing across the network.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Laser coupling to single-mode fibre using graded-index lenses and compact disc 1.3 μm laser package

A 1.3 μm laser in a compact disc package is coupled to single-mode fibre using two graded-index lenses in a nearly confocal scheme. An increase in the alignment tolerance at the lens-lens interface by a factor of six suggests the design for a potentially very low-cost connectorised laser package. The coupling efficiency of approx. 6% (-12 dB) is shown to be adequate for local loop applications.