Robotics Sportster Flash x2 Manual de usuario descargar pdf (Pagina 3)

equipment located in the neighborhood. In many cases it is provided as a digital

extension of the switching equipment.

This is good for x2 because it extends the digital portion of the network to the

neighborhood and reduces the length of the analog portion (the portion most susceptible

to interference and distortion). The equipment that aggregates lines and performs signal

conversion is often called a DLC (digital loop carrier).

There are other cases, often when the switching equipment is not capable of digital

“extensions,” in which analog lines are provided from the switching equipment. In these

cases, the analog signals are converted to digital for transmission over the digital carrier

to the neighborhood, then converted back to analog for delivery to the subscriber’s home

or business.

Although this is a simple method of modernizing the local loop, providing higher

quality voice transmission and more lines over fewer copper wires (reducing the need to

tear up streets to add capacity), the additional analog-to-digital conversion prevents the

operation of x2.

There are also other conditions that affect the local loop and either prevent x2 or reduce

the maximum speed. The farther a customer’s site is from the switching equipment, the

more likely that “load coils” have been installed on the line. Load coils are typically

employed on longer wire lengths, and are used to offset some of the negative effects of

these longer loop lengths on voice transmission. They will often reduce the speed,

affecting V.34 and other modulation techniques as well as x2. Other problems may

include poor wiring either in the telephone network or even inside homes or businesses.

2. Problems within the network

Many problems that can occur within the network will likely be intermittent and vary

from call to call, and are more likely to occur on long-distance calls. The reason these

are intermittent is that the “path” a call takes varies from call to call, and a call from

one point to another may take a different path each time the call is placed depending on

the current utilization of “inter-office trunks” and other switching gear.

The most common issue is a digital pad where the digital bits (PCM) are manipulated to

reduce the volume. This causes problems for x2, but it has been overcome using

complex mathematical computations within the modems at each end. The presence of

digital pads may cause a minor speed reduction, but it should not prevent x2 from being

achieved altogether.

It is possible that we have not identified all the possible pads. If you see a line that

should work, but does not, please try to grab the ATI6, ATI7, ATI11 and ATY11

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Robotics Sportster Flash x2 Manual de usuario Pagina 3