On the remote end of the line, HDSL uses a minimal amount of power, making remote powering from the central office feasible. HDSL solutions are deployable in over 99 percent of the local loop plant. No cable conditioning, bridged tap removal or cable plant reinforcement is required with HDSL. The elimination of repeaters increases overall system reliability and transmission performance.
No separate monitoring equipment is required with HDSL. Through today's advanced electronics, HDSL is immune to crosstalk, while yielding signal quality comparable to fiber optics, bit error rate BER The first such application involves services provided by the phone companies, generically labeled public network access or data network access.
The local phone company provides that service and charges you for it, based on applicable local tariffs. In this setting there is a natural role for HDSL to play. Outside of the telco setting, HDSL is becoming increasingly effective in campus area networks.
In this context, a campus is defined as a setting where multiple locations or buildings are located a few miles or kilometers apart, a single building with multiple floors or a single building spread over an expanse of real estate e. The implied commonality in any of these campus situations is an embedded copper cable plant. Traditionally, campus area networks are prevalent in a number of industries, including local, state and federal governments and utility companies.
Fiber backbone extension-using HDSL and traditional copper circuits to connect with high-speed fiber optic backbones across acampus network. There are several opportunities within a campus setting in which HDSL implementation is extremely effective-where it can be established quickly, cost-effectively and where it can serve a specialized, valuable function. Fiber access In many larger metropolitan areas, cities have gone to great lengths, and spent millions of dollars, to install vital fiber backbones using SONET Synchronous Optical Network in the U.
Due to cost and logistical factors, the scope of these backbones is limited, with only a relatively small percentage of sites being able to tap directly into the backbone.
There often remains a great many associated city buildings and end users that could benefit from access to this fiber, but direct fiber connection is prohibitive. This situation is a perfect fit for HDSL. With HDSL, satellite locations can be linked quickly, transparently and inexpensively, using existing copper to produce fiber optic-quality transmission BER Traditionally, fiber is employed within a campus area network on a more conservative basis, usually being used to connect a small number of buildings or to connect critical users at just one site.
These limits are designed to provide reasonable protection against harmful interference when the equipment is operated in a commercial environment.
This equipment generates, uses, and can radiate radio frequency energy and, if not installed and used in accordance with the instruction manual, may cause harmful interference to radio communications. Operation of this equipment in a residential area is likely to cause harmful interference in which case the user will be required to correct the interference at his own expense. Cautions indicate the possibility of equipment damage or the possibility of personal injury. If it has been damaged in transit, report the extent of the damage to the transportation company and to ADC immediately.
Order replacement equipment if necessary. If you need to store the unit for several days or more before installing it, return it to the original packaging. Features of the Line Unit Surge Protection Install the Line Unit Some cards may support fewer rates or only one rate. User manuals, Pairgain Modem Operating guides and Service manuals.
There are NO accessories, manual, or software included. ConferenceI'd like to recommend the place where everyone could probably find pairgain hre manual arts, but probably, you would need to register there. This action must be confirmed by pressing Y. Dashes -- indicate an inactive line.
OFF indicates an inactive line. Figure 41 shows a point-to-point NTU Interface screen. Table 24 on page 52 describes the fields displayed. Figure 44 shows a point-to-multipoint application. Table 24 describes the fields displayed. The normal range of a typical margin is from 6 to 22 dB, with a value of 6 dB corresponding to a predicted BER of Low Margin dB Indicates the lowest margin since startup or the last hour history clear.
High Margin dB Indicates the highest margin since startup or the last hour history clear. The normal range of pulse attenuation is from 1 to 32 dB. Pair Exchange Indicates whether the HDSL pairs carrying the traffic are correctly connected or have been interchanged. The system automatically compensates for an interchange of pairs. The system automatically compensates for an interchange of wire leads. Clear Hour History Clears all hour history counters including G.
Press H to select the History menu. Figure 45 shows the History menu for a point-to-point application with no doubler. Figure 46 shows the History menu for a point-to-point application with one doubler. Figure 47 on page 54 shows the History menu for a point-to-multipoint application. A dash - represents a count of zero. First Date and time the alarm first occurred.
Last Date and time the alarm last occurred. Count Number of times the alarm has occurred since the alarms were last cleared. If no alarm has occurred since the last alarms were cleared, the message No Alarms Reported is displayed on the appropriate line for each alarm.
These alarms signal the conditions listed in Table The Span 2 menu is available with one doubler in the network and the Span 3 menu is available with two doublers. The entire display consists of six screens, each showing sixteen minute intervals 4 hours of performance history.
If no alarm has occurred since the last alarms were cleared, the message No Alarms Reported displays on the appropriate line for each alarm.
Table 28 on page 63 describes the fields displayed in each Inventory screen. Press I to display the Inventory screen. Figure 57 shows an Inventory screen for a point-to-point application.
SW Date Displays the date that the firmware was released. These loopbacks include configurations for point-to-point, point-to-multipoint, and doubler applications. Figure 60 on page 65 shows all possible loopback paths. The available loopbacks are listed in Table 29 on page When loopbacks are activated the system generates an AIS past the loopback point toward the far unit.
During a loopback, the Loopback LEDs on the front panel indicate the type of loopback in progress. The system reverts to normal transmission of payload data after the specified timeout period has elapsed. If a timeout period is not specified, the loopback must be manually disengaged before normal transmission of data can resume. Test loopbacks disrupt the normal end-to-end transmission of customer data.
Be sure you are authorized to bring an operational circuit out of service before engaging any loopbacks. The circuit does not revert to normal until loopbacks are disengaged manually or until after the specified loopback time-out period has expired.
Bevor man irgendwelche Schleifenbetriebe aktiviert, stellen Sie sicher, dass nur autorisiertes Personal einen aktivierten Stromkreis ausschalten duerfen. The remaining loopback options are available exclusively from the Console screens or management unit interface. Local Interface Loopback Data is looped back at the closest point in the local unit toward customer equipment.
The HDSL link is maintained during this loopback. Customer to LTU interface loopbacks Loopbacks are not supported. Local or Interface Loopback Data is looped back at the local unit or remote unit back toward the remote DTE equipment. The injected test data and loopback verification must still be performed at the remote unit site.
Local equipment outputs an AIS for the duration of this test. This is available at the the Local Equipment local Console screen for the duration of this test. There is no independent control for either interface. The test is run at the full 2. BER results are accumulated continuously and updated on the Console screen at intervals of approximately 16 seconds bits at 2.
The BER test must be stopped before leaving the Test screen in order to restore normal payload transmission. Must STOP before leaving screen. Bevor man es verlaesst muss es gestopt werden. Figure 61 shows the Test screen for a point-to-point application. Figure 62 is a Test screen for a point-to-point application using one doubler. Figure 63 on page 69 shows the Test screen for a point-to-point application using two doublers. Figure 66 on page 78 is a Test screen for a point-to-multipoint application.
Table 31 on page 70 describes the Test screen loopback options and Table 32 describes the BER options. Test Screen for Point-to-Point Applications The loopback remains active until the timeout elapses or the configuration changes.
Loopback location and status are indicated by displaying the characters " ]"on the network diagram. If the characters are displayed in flashing reverse video, the loopback is active. If the characters are displayed in solid reverse video, the loopback is disabled. LOOP1 Only loop 1 is used in the loopback test. LOOP2 Only loop 2 is used in the loopback test.
In PTM mode, this loopback is not supported if both loops are selected for loopback. STOP Terminates the current test and resumes normal transmission of user payload. Prior BER tests are maintained for reference on the screen. The actual pattern used is a 2e15 pattern as defined by reselecting this option pressing the ENTER key while the test is running.
This entry re-initiates the BER values and restarts the test. The BER meter accumulates errors once per test interval 16 seconds. In a high bit error environment the test interval is shortened and the BER meter is updated every second. This field is updated every 30 seconds, with a maximum value of per update. This field is updated very 16 seconds, as is displayed in exponential form. The lowest positive displayable value is 1x The upper area of the menu displays the configuration options, and the lower area displays messages during the download process.
Instructions for using the download menu are provided Figure The number of data bits is fixed at 8, with no parity and 1 stop bit. Table 34 describes how to navigate the firmware download menu.
While downloading, the line card front panel LEDs all light, then a binary count sequence indicates progress. When downloading is complete, the unit resets. It is essential that when the equipment is installed in a receiver, the minimum creepage and clearance distances between the equipment and any devices that use or generate hazardous voltages With the exception of the host connection, the minimum distance must be maintained between the card and all other assemblies that use or generate the voltages shown.
The larger distance shown in brackets applies where the local environment within the host is subject to conductive pollution or dry non- conductive pollution that could become conductive due to condensation. Failure to meet these minimum distances would invalidate the approval. The HDSL cord must remain disconnected from the telecommunications system until the card has been installed and the cover replaced onto the receiver.
Nx64k Interface The Nx64k serial interface provides a high-speed synchronous interface for the transport of serial data at rates from 64 kbps to 2. The user can configure the rate, in 64 kbps increments, at which the HDSL card transmits and receives data from the Nx64k interface. An example is shown in Figure Select Unstructured Mode for applications using Nx64k interface ports at both ends of the circuit. Transmission of Nx64k Serial Data Figure 68 shows a fractional application where the Nx64k serial data is being transferred over an E1 network.
The application mode must be structured and the maximum data rate available at the Nx64k port is kbps. Time slot 0 is regenerated at the G. ADC offers V. Line units are always configured as DCE. Overhead bits are stripped and processed, and time slots are output to the G. It is recommended, however, that the pairs not be swapped in order to ease diagnosis and repair of loop-related problems.
Reversals of Tip and Ring wires for each pair are also automatically detected and accommodated. Timing for the signals transmitted over the HDSL link is nominally derived from the selected primary timing source. In case of failure of the primary timing source, the system uses the internal 2. Figure 69 on page 81 illustrates the Transmit Clock circuit function.
When the data port has Nx64k selected as its primary timing source, the transmit clock is fixed to External. The purpose of this selection is to compensate for a possible phase shift between SD and ST due to long interface cables or delay added by the DTE.
Local and Remote Power Supplies The line units are powered by dc voltage. Monitoring circuits automatically disable the power feed mode if the voltage on a line exceeds V or if the current exceeds 50 mA.
The Remote Power Feed mode should not be enabled on LTUs that are connected to baseband analog circuits that are part of the public telecommunication network in the United Kingdom. The NTR 14 limits the maximum open circuit voltage to Vdc. Der Betrieb der Fernenergiezuspeisung sollte nicht auf LTUs aktiviert werden, welche an analoge Stromkreise des Basisbandes angeschlossen werden und die an das englische allgemeinen Fernmeldenetzes sind.
The appropriate application mode can be selected when configuring the HDSL system. Unstructured Mode Unstructured mode provides unframed transport of data at up to 2. Dual-port operation use of both the G. Figure 70 illustrates a typical unstructured mode application. The options and settings listed in Table 36 are defined in Table 10 on page 24 and Table 11 on page This allows the fractional allocation of the total 2. Figure 71 on page 85 illustrates a typical structured mode application.
Table 37 on page 85 lists the typical structured mode system settings. The options and settings listed in Table 37 are defined in Table 10 on page 24 and Table 11 on page Time slot 16 is transported transparently between G. Typical Structured Mode Application Table In structured mode, with the CRC-4 mode enabled or disabled, time slot 0 is regenerated according to G.
All other time slot 16s in the multiframe are used for ABCD signaling bits which give supervision information for each payload time slot. The MA signal is applied as necessary to obtain frame alignment in mixed interface applications such as G. In the case of a single loop failing, the time slots in that loop will be set to 0xFF, with the remaining time slots unaffected.
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