Blooming America

ATT belongs to Bell Lab.

At this time, they are studying a thing.

- Broadband.

The ATT does not want the meeting to be husted on the comet plan.

In addition, ATT also has its own plan.

The thing they are now doing - R & D belongs to their own broadband network.

Catherine is a broadband network across the United States.

However, ATT has no support for the US government, although the five-corner building is stupid, but they will not invest in the same thing, so ATT is only

You can choose to use their existing techniques to break through the network's seal lock.

The power of the Internet has been paid attention to, and this power contained in the interests have been noticed by ATT.

They can't ignore this market.

And in a sense, they are more advantageous than Catherine.

Optics requires a dedicated broadband, but ATT's plan, but uses telephone lines they already have to access the Internet.

Catherine is indeed aggressive, but ATT is not full of defense.

In fact, as long as they want to do, their advantages are more huge than Catherine.

For ATT, for a long time, the telephone user's telephone is connected to the city exchange bureau, and enter public exchange network

(PSTN), pick up to the telephone number of the other user, so that the two sides will session each other.

A frequency band of 300 ~ 3400 Hz is provided for the traditional simulation call. ATT has tried the modem to make the rate of 33K in order to adapt to the telephone user using low-speed data communication.

s and up to 56K

The data signal of S can implement data communication with the other party through analog voice strip. This is the beginning of their Tang Ge.

Although the double-stranded copper wire does not have a bandwidth limit, they also have the same level, but the switch in the communication network is limited,

It is only assigned a voice band for telephone communication. Although the user's data information is transmitted by the modem, the switch does not recognize that it is a data signal from the modem, but only treats it as a voice signal.

At the same time, at this time, ATT also hit a difficult situation in history.

That is, one "last km".

The original meaning of this word refers to the last mileage of long journeys, and is incorporated herein by reference to the end of a matter (usually explaining this step by difficulty). The communication industry often uses "last kilometers" to refer to the connection between the computer room switches of the communication service provider to terminal devices such as user computers. Users involved in the "Last Gri" refer to users and individuals in the network terminal, rather than large commercial users or professional communications companies, so connecting the service providers and users Will be a single-mode fiber that is usually used by osse thousands of networks. "The last kilometer" also involves the problem of wiring the location where the terminal equipment such as the user's computer is different. Since each user has different rooms, communication service providers, real estate developers and users need to consider the actual situation. How to connect user equipment into the network, how to migrate to other locations and how to log out of user services.

In this way, there is a problem.

Therefore, ATT thinks is a transmission mode similar to ADSL, which is part of Catherine's "digitization".

In fact, with the traditional telephone line system is the low frequency part of the copper wire. Their technical practicality is already completely no problem, but if such, ATT discovers, the system's transmission speed It is a difference that is universal.

The techniques they use now are DMT (discrete multi-audio) technology, and the original telephone line 40kh frequency band 506 frequency width is a sub-band of 4.3125 kHz. The frequency band of 4kHz below is used to transmit the TS (traditional telephone service), 20kHz to 138 kHz, used to transmit the upper line signal, and the 138kH band is used to transmit the downlink signal. The DMT technology can adjust the number of bits modulated on each channel according to the case of the line to sufficiently use the line. In general, the larger the signal-to-noise ratio of the subchannel, the more bits modulated on the channel, and if a subchannel signal to noise ratio is poor, it is not necessary. At present, ADSL can reach upstream 640K

PS, downstream 8M

PS data transfer rate.

In other words, in theory, up to 3.5m can be provided without affecting normal telephone communication.

PS upstream speed and up to 24m

PS downstream speed.

That is, the download speed is up to 3MB

S.

Although it is the theoretical speed, this speed has been able to fight Catherine's broadband.

Through such DMT technology, ATT can use the user's line to avoid narrowband voice switches, it can be "digital subscriber line".

ATT called Tal-Su

-ne, that is, DSL.

DSL technology supports symmetrical and non-symmetrical transmission modes on the user line of the traditional telephone network, solves the issue of the "last kilometer" transmission bottleneck in the network service provider and the end user. Since the telephone subscriber loop has been laid a large amount, how to make full use of existing cable resources, high-speed access through copper twisted pair is a focus of ATT next research.

But when it is time, their technologies will definitely be practical. At that time, Catherine was nothing.

This conclusion is that it is a rejoiced message for Att.

... When studying at ATT rejoicing, Catherine is already a Thunder laboratory.

Now in this world can be comparable to the Bell Lab, there is only a Thunder laboratory.

However, Catherine did not preach his own plan.

In fact, Catherine At this time, the Thunder laboratory that is interested in the future is ready to come.

One is preparing to plan to develop a mechanical UPS power supply.

UPS (NTE)

Le-we

-System, that is, uninterruptible power supply.

This is an uninterruptible power supply containing constant voltage constant frequencies containing the energy storage device with inverters. Mainly used to provide uninterrupted power supply to a single computer, computer network system, or other power electronics. When the main electricity input is normal, the UPS supplies the market to the load, at this time, the UPS is an exchange of electric motor regulators, and it also charges the battery in the machine; when the city is interrupted (accident shutdown) When the UPS immediately continues to supply 110V AC electricity through the method of inverter conversion, so that the load is maintained normally and protects the load, the hardware is not damaged.

In general, the Super Computer Center requires a UPS power supply to protect data from the security of data.

Inside the North American computer center, a series of UPS power supplies, which are the core of the power storage, which is produced.

These UPS ensure that they can initiate the generator in time when suddenly occurring power failure, maintain the normal operation of the supercomputer.

But such power storage UPS is not perfect.

So this time, Thunder laboratory is thinking about a solution that can be perfectly resolved.

This is now their conclusions a mechanical battery.

That is, the flywheel battery.

Prior to the use of the battery, the uninterruptible power supply has supplied electrical supply to the load using the flywheel and the internal combustion engine, which is called a flywheel or rotary uninterrupted power supply. The flywheel uninterruptible power supply consists of rectifier, DC motor, flywheel, diesel engine (or gasoline engine) and generators. In the case where the grid is powered, the DC drive motor supplied from the rectifier drives the flywheel, and the generator is powered by the load. Due to the inertial role of the flywheel, the generator speed can be balanced. At this time, the uninterruptible power supply functions as a scramble of the filter grid. When the grid is disconnected, the flywheel continues to rotate the rotor of the generator while starting the diesel engine with a generator power generation, and replacing the original grid to power supply.

In now, this flywheel battery has been resected.

This is a new program of Thunder Lab ... according to the design of Thunder laboratory, there is a motor in the flywheel battery. When charging, the motor is operated in the form of a motor. Under the driving of the external power supply, the motor drives the flywheel to rotate, that is, electricity The flywheel battery "charging" increases the speed of the flywheel to increase its function; when discharging, the motor is operated in the state of generator, and the electrical energy is output in the flywheel, and the mechanical energy (kinetic energy) to the electrical energy conversion.

When the flywheel battery is applied, the flywheel speed gradually decreases, and the flywheel of the flywheel battery is operated in a vacuum environment and the speed is extremely high. "The bearing used is a non-contact magnetic bearing. This allows effectively to reduce friction." Technician really tells her.

(This is useful to use the legendary magnetic suspension?) Catherine spits in the heart.

The flywheel battery, Catherine also heard, but Catherine didn't use it.

In fact, Catherine has very little contact for UPS.

But this does not affect Catherine to optimize the prospect of this industry. This is already enough even yourself.

So Catherine is very satisfied with this plan. "You can do it well, I support!"

She said like this.

"It's not enough to say it ...

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