Tài liệu KRONE - White paper - ADSL Service Delivery - 2003 pptx

Analyzed methods include dedicated pair count, protected jumper, wire-wrap management cabinet and the KRONE Asymmetric Digital Subscriber Line ADSL delivery solution.. Remote Terminal Pa

White Paper

ADSL Service Delivery

January 21, 2003

A comprehensive look at the challenges of rapidly delivering

ADSL services, keeping up with the subscriber demand, and

controlling operating expenses.

This white paper analyzes several methods of connecting a Digital Subscriber Line Access Multiplexer (DSLAM; and splitter) to the outside plant Analyzed methods include dedicated pair

count, protected jumper, wire-wrap management cabinet and the KRONE Asymmetric Digital

Subscriber Line (ADSL) delivery solution The analysis primarily focuses on remote equipment deployments serving lines provisioned on pair-gain or Digital Loop Carrier (DLC) systems

General

ADSL has emerged as the broadband access technology of choice for most telephony providers throughout the world While the initial deployment of DSLAMs rushed to keep pace with

burgeoning customer demand, current conditions require greater consideration of regulatory and economic factors Increased scrutiny mandates no less than optimal deployment of capital spending

In contrast to dial-tone, DSL is not ubiquitously available While the location of DSLAM

deployment is critical, the efficiency of the equipment’s interface with the outside plant is

paramount Slight idiosyncrasies in this interface can result in substantial service interruptions (both voice and data), underutilization of the DSLAM and dramatic increases in operating

expenses

ADSL service is unique in that it can be deployed on the existing cable pair, sharing the line with voice dial-tone While this equates to cost savings for the operating company and subscriber, it also comes with some deployment issues The customer’s dial-tone must be interrupted and then re-routed through the DSL equipment to be combined with the data The combined voice and data must then be connected back to the cable pair

ADSL is deployed in central offices, Controlled Environmental Vaults (CEV), and from Remote Terminals (RT) No matter where the service is deployed the process to deliver the service is the same The Plain Old Telephone Service (POTS) dial-tone must be re-routed into a splitter (filter) where it is combined with the data service This combination must then be connected back to the cable pair

DSLAM

Fiber or Copper T1

From Central Office

POTS in from RT

ADSL and POTS Subscriber line to Customer

Remote Terminal

Before looking at each of the ADSL deployment methods this section will review the basic remote

terminal The trend for several years has been to deploy remote terminal cabinets instead of

building new central offices when network growth is required Digital Loop Carrier (DLC) systems

have been widely used throughout the network These cabinets are equipped with active

electronic equipment creating a derived dial-tone These cabinets can be fed by copper T1

circuits or fiber optics The DLC remote terminals can be deployed quickly when additional

capacity is needed in the network In the past, operating companies would have to place more

feeder cable to increase capacity Now, remote terminals increase capacity quickly The diagram

below shows the basic remote terminal and will be the basis of discussion for each of the ADSL

deployment methods

Remote Terminal Pairgain System

Cross box

Telephone NID

Drop Fiber feed to CO

Existing Remote Terminal

Typical Remote Terminal

Methods of ADSL delivery

The following diagram will be used to illustrate several methods of ADSL delivery

Remote Terminal

Pairgain System

Cross box

(Feeder)

(Distribution)

Telephone

NID Drop

Remote Terminal with ADSL

Various methods of ADSL Delivery

ADSL Solution

1.

2.

3.

Computer Microfilter

W ire Management

Cabinet

Fiber feed

to CO

Connecting a DSLAM to the Outside Plant:

Dedicated Pair Counts Method

Description

This ADSL deployment method dedicates a particular pair count for ADSL in the feeder cable that

leaves the remote terminal It requires dedicated pairs for the voice inputs and then dedicated

pairs for the combined output This method provides the capability to address multiple cross

boxes However each feeder cable would have some pairs dedicated for ADSL (See item 1 in

above diagram)

Service Delivery

This method requires the technician to access the cross connect cabinet, then identify the

distribution pair that has requested service The cross connect jumper that is connecting the

distribution pair to the feeder pair must be removed During this time the customer’s service is

dropped New jumpers must then be run from the distribution pair binding post to the ADSL

output binding post in the cross box Then a jumper must be run from the feeder binding post to

the ADSL input binding post The dial-tone is routed into the DSL solution and then back from the

DSLAM to the cable pair with the voice and data combined

To disconnect service, the technician must remove the two jumpers that are running to the

DSLAM input/output binding post and run a new jumper between the feeder pair and the

distribution pair The customer’s service is dropped during this disconnect and re-wire

period.

Connecting a DSLAM to the Outside Plant:

Protected Jumper Method

Description

With this approach, a protection field within the remote terminal is used to gain access to the dial-tone and re-route into the DSLAM A custom protector unit is equipped with a 2-pair jumper wire that exits the rear of the protector module Inside the RT cabinet a connecting block is added for the inputs to the DSLAM splitter and the combined outputs Typically, this is a wire-wrap block

and is cabled to the DSLAM solution (See items 2 on above diagram)

Service Delivery

To activate service, the technician unplugs the protector module on the selected cable pair The customer’s service is dropped during this re-wiring process The protector with the 2-pair

jumper is inserted into the protector field The jumper is then routed inside the cabinet to the ADSL interface terminal block The technician strips and wire-wraps the ends of the jumper to the respective voice input and combined output The completed process activates ADSL service for the customer

To disconnect service, the technician removes the protected jumper coil from the protector field

and inserts a standard protector The customer’s service is dropped during this process.

Connecting a DSLAM to the Outside Plant:

Wire Management Cabinet with Wire-wrap Interface Method

Description

This delivery method utilizes a separate cabinet to handle the ADSL circuit wiring A separate cabinet either attaches directly to the remote terminal, or can stand alone on a nearby pad The cabinet is equipped with wire-wrap blocks for the ADSL input/output and blocks for the pair-gain/cable pair appearances Every one of the dial-tone circuits appear in this special cabinet Each of the pair-gain terminal blocks is equipped with small straps that connect through the dial-tone to the cable pair Basically the pair-gain and cable pair appearances within the wire

management cabinet are positioned between the dial-tone source and the cross connect box

(See items 3 on above diagram)

Service Delivery

To deploy service with this method, a technician gains access to this cabinet and removes the

wire-wrap straps from the cable pair requesting service The customer’s service is dropped during this step Next the technician must add a jumper from the pair-gain (dial-tone) to the

ADSL input terminal block and another jumper back to the cable pair block This re-routes the dial-tone into the ADSL solution and back to the customer cable pair

To disconnect service the technician must remove the jumpers from the input and output and

place small wire-wrap straps back into position between the cable pair and the feeder circuit The customer’s service is dropped during this operation.

Connecting a DSLAM to the Outside Plant:

KRONE ADSL Delivery Solution Method

Description

Two variants of the KRONE Series 2 block are used in this application, the Disconnection block

and the Switching block They share many features, yet each has a unique function that creates

a streamlined ADSL delivery platform

The Series 2 Disconnection Block has a built-in cut-through so that if the remote terminal

dial-tone is connected to the top of the block and the cable pair is connected to the bottom of the

block, the subscriber dial-tone is connected and there are no additional straps or connections

required

This cost-effective and timesaving solution enables access to the dial-tone pair, yet in the idle

state all subscribers maintain POTS service One of the best features of this solution is that

nothing must be added back to the Series 2 Disconnection Block when disabling ADSL service

and reconnecting dial-tone to the cable pair No additional straps or jumpers are required to

reconnect dial-tone to the customer

The KRONE Series 2 Switching Block is used for the connection of the ADSL input (voice) to

the splitter which is wired to the bottom of the block, and for the ADSL combined output (voice

and data) from the splitter wired to the top Since this block is an open circuit block (until a

connection is made using a test plug, protection device, etc.), the test port is perfect for storing

KRONE’s plastic Disconnection Plugs, which are essential for the next piece of the KRONE

solution

Diagram

Remote Terminal Pairgain System

Cross box

(Feeder)

(Distribution)

Telephone

NID Drop

Existing Remote Terminal with KRONE ADSL Delivery System

ADSL Solution

KRONE ADSL Delivery Cabinet

T R To Field

T R PairGain

ADSL In ADSL Out

KRONE series 2 switching module used for the ADSL in / out terminations

1 to Pairgain

2 to Crossbox

3 From ADSL system

4 to ADSL system

1.

2.

3.

4.

KRONE ADSL Delivery cabinet detial

Computer

Microfilter Fiber feed to CO

Service Delivery

The KRONE solution enables ADSL service when the technician simply connects a jumper to the cable pair appearance and routes it to the ADSL input (voice) The technician then terminates another jumper from the cable pair appearance (directly below the dial-tone on the Series 2 Switching Block) to the ADSL output (voice and data) This position happens to be directly above

the input on the Series 2 Switching Block It is important to note the technician has

maintained the subscriber’s POTS service during all wiring activities Thus, the dial-tone

is still connected to the cable pair and there is no service interruption.

The last step is to insert a KRONE Disconnection Plug into the dial-tone / cable pair block

(Series 2 Disconnect Block) This plug was removed from the ADSL block (Series 2 Switching Block) prior to connecting the jumpers When this plug is inserted, the cut-through between the dial-tone and cable pair is opened and the dial-tone is re-routed into the ADSL splitter where it is combined with the data The signal is then routed back up to the cable pair and out to the

subscriber

To disconnect service the technician would remove the disconnect plug from the Switching block, instantly restoring the internal bridge of RT dial tone to cable pair The jumpers are then removed

from both the Disconnect and Switching block Again, there is no service interruption during

this process.

The KRONE ADSL delivery solution is modular and can be deployed in a central office, CEV, or

cross box The idea of having a separate location to gain access to the dial-tone and re-route into the DSLAM with the extra testing capabilities offered by the KRONE system, creates a cost effective, streamlined ADSL delivery platform

KRONE Solution in large cross

box 1800 pairs 600 ADSL

KRONE Solution in smaller application

ADSL Deployment Issues Dedicated Pairs Protected

Jumper

Wire-wrap interface

KRONE Solution

Can solution be expanded easily as

growth is required?

Does not require removal of special

wiring to disconnect ADSL and restore

POTS?

Is solution familiar to field technicians? Yes No No Yes

Is customer’s POTS maintained when

wiring the circuit for ADSL?

Does the solution offer test access

without lifting wires?

Can ADSL delivery solution be

implemented quickly?

Can solution be deployed in CO, CEV,

and cross box?

No Potentially Potentially Yes Does solution address 100% of available

pair count?

Only if single cross box

Yes Only in single

cabinet arrangement

Yes

Does solution offer a quick visual of who

has ADSL and who does not?

Is customer’s POTS maintained when

disconnecting ADSL?

Conclusion

There are several ways to approach ADSL service delivery All address the main issue of re-routing the dial-tone to be combined with the ADSL solution There are several matters operating companies should consider when choosing a method

• What may seem to be a low-cost method at first, and seems quickly deployed, may have issues that in the long run could cause more problems and cost more money

• Solution should be scalable Planning may show a particular growth rate for an area, yet this may be exceeded quickly The method must address expansion, which may be accomplished easily without a lot of rework

• The solution should be technician friendly Training technicians is costly and a

straightforward method of implementation simplifies training issues

• Solution should lend itself to “doing it right” It should be easy and straightforward for the technicians; this will help to ensure successful mass deployment

• Default to customer having POTS service To provide ADSL service the customer’s tone must be re-routed Make sure the selected solution offers default to customer dial-tone Do not depend on the technician re-wiring, or placing jumpers back into place to ensure that the customer’s fall back position is dial-tone

• It is important that the solution offers complete customer satisfaction The goal is to increase ADSL market share, maintain satisfied customers, and have an ADSL network that is reliable The connection system should be viewed as a critical part of the equation

• Long-term reliability, with minimal trouble The method should provide many years of trouble free service, so that everyday system use and the connects/disconnects

performed over time do not deteriorate and begin to cause more problems