Tài liệu Dynamic Reconfiguration of Indoor Combination Networks Through the Use of Patch Panels pdf

4 484 0
Tài liệu Dynamic Reconfiguration of Indoor Combination Networks Through the Use of Patch Panels pdf

Đang tải... (xem toàn văn)

Thông tin tài liệu

Dynamic Reconfiguration of Indoor Combination Networks Through the Use of Patch Panels Executive Summary In terms of flexibility, the traditional combination networks found inside hubs and headends are quite rigid, making it difficult to change combination ratios. Adding radio-frequency patch panels to combination networks adds a high degree of flexibility and allows for different levels of combination without affecting network service. Issues in Traditional Configuration Networks Over the past few years, cable operators have encountered an unexpected problem integrating high-speed data and integrated telephony services. Initially, high-speed data and integrated telephony services were deployed using a design that assigned fixed ratios of combination between the number of homes and the controller inputs in hubs and headends. For example, operators often assigned 1,000 homes to a DOCSIS upstream input for cable-modem service. As a result, it’s common to find a first splitting stage just after the optical receivers inside the hubs in an upstream network. Following the first splitting stage is a series of combination stages that group the return path of the optical nodes in ratios that vary according to the provided service. Using high-speed data as an example, these stages could result the grouping of a signal coming from eight optical nodes into one CMTS upstream input. This creates a rigid ratio structure with fixed combiners and splitters that condition the service. A clear example can be seen in the following illustration, where the number of cable-modem users has grown and the combination networks limits the number of users that can be served by the network. APPLICATION NOTE www.adc.com • +1-952-938-8080 • 1-800-366-3891 Groups of 8 Upstream Signals Groups of 8 Upstream Signals Groups of 32 Upstream Signals Cable Modem Concentration Stage Distribution Stage Switch Opt. Rec. Opt. Rec. Opt. Rec. Opt. Rec. Opt. Rec. Opt. Rec. Switch Switch Integrated Telephony Concentration Stage Conditional Access and Monitoring Concentration Stage Alternative Through the Use of Radiofrequency Patch Panel Necessary Situation After Growth of Penetration In this example, subscriber penetration causes the need for change from Initial Situation to Necessary Situation. It forces reengineering the network along with adding and removing devices and cabling. One solution to this dilemma is to create a more flexible combination network. The inclusion of patch panels provides the needed flexibility, providing for growth without negatively affecting existing cabling and devices. The following diagram illustrates how, with the addition of patch panels, an operator can change the ratio of optical nodes attached per upstream input in the CMTS, resulting in the following advantages: • As the ratio changes, there is no effect on the fixed cabling as all the fixed cabling is on the rear side of the patch panels • Changes can be made without affecting service as it’s only necessary to make the change in the CMTS input • New services and nodes can be added without affecting service • New CMTS or Integrated Telephony cards can be added to the shelves without affecting service 7/05 • 1332621 Dynamic Reconfiguration Dynamic Reconfiguration of Indoor Combination Networks Through the Use of Patch Panels 2 www.adc.com • +1-952-938-8080 • 1-800-366-3891 CMTS Input 1 500 Users Maximum 2000 homes in 4 optical nodes 500 can be served 25% penetration 4:1 CMTS Input 1 500 Users Maximum 2000 homes in 4 optical nodes 1000 can be served 50% penetration 2:1 CMTS Input 2 500 Users Maximum 2:1 Initial Situation Distribution Stage Concentration Stage Opt. Rec.1 Opt. Rec. N Flexible with Patch Panels at Different Stages It’s important to note that while the diagram shows the return path of the network, the same philosophy should be applied to the downstream path. 7/05 • 1332621 Dynamic Reconfiguration Dynamic Reconfiguration of Indoor Combination Networks Through the Use of Patch Panels 3 www.adc.com • +1-952-938-8080 • 1-800-366-3891 4:1 4:1 CMTS 1 CMTS 2 4:1 CMTS 1 4:1 4:1 CMTS 1 CMTS 2 1. Initial Situation Combination of 4 Nodes per Upstream Input in the CMTS 2. Temporary Change Without Affecting Service to a Combination of 2 Nodes per Upstream Input in the CMTS 3. Final Situation Combination of 2 Nodes per Upstream Input in the CMTS SJ-2000 Jack The flexibility described in this example is based on the functionality of SJ-2000 jacks. The use of this jack allows instantaneous signal rerouting. Patch panels act as the mechanical support for the jacks. The two rear connectors are bridged as the jack acts as a loop with the front connectors 75 Ohm-terminated. When a jack is inserted into any of the front inputs, the corresponding rear connection is rerouted to the front and goes through the inserted jack. Simultaneously, the unconnected connections are grounded to avoid RF interference. ADC Telecommunications, Inc., P.O. Box 1101, Minneapolis, Minnesota USA 55440-1101 Specifications published here are current as of the date of publication of this document. Because we are continuously improving our products, ADC reserves the right to change specifications without prior notice. At any time, you may verify product specifications by contacting our headquarters office in Minneapolis. ADC Telecommunications, Inc. views its patent portfolio as an important corporate asset and vigorously enforces its patents. Products or features contained herein may be covered by one or more U.S. or foreign patents. An Equal Opportunity Employer 101107 9/05 Original © 2005 ADC Telecommunications, Inc. All Rights Reserved Web Site: www.adc.com From North America, Call Toll Free: 1-800-366-3891 • Outside of North America: +1-952-938-8080 Fax: +1-952-917-3237 • For a listing of ADC’s global sales office locations, please refer to our web site. APPLICATION NOTE Normal Operation Loop Patch Operation (Reconfiguration) Routing Through the Front Inserted Jack . Dynamic Reconfiguration of Indoor Combination Networks Through the Use of Patch Panels Executive Summary In terms of flexibility, the traditional combination. service 7/05 • 1332621 Dynamic Reconfiguration Dynamic Reconfiguration of Indoor Combination Networks Through the Use of Patch Panels 2 www.adc.com • +1-952-938-8080

Ngày đăng: 10/12/2013, 18:15

Từ khóa liên quan

Tài liệu cùng người dùng

  • Đang cập nhật ...

Tài liệu liên quan