Light Behave As a Solid? a New Theory , tasks

Task1. Find words meaning the following:

1. Wandering

2. A great success;

3. To reproduce;

4. To happen;

5. To connec t;

6. To force something similarly magnetized or charged away from each other;

7. The conditions that affect a situation, event

Task2. Answer the following questions.

1. What do solid light photons and electrons have in common ?

2. Why is this property so important?

3. Do photons and electrons behave in a similar way under ordinary conditions?

4. What is a phase transition?

5. What does it mean for photons?

6. This phenomenon is well understood ,isn’t it?

Lmds: Broadband Wireless Access

Ground-based wireless networks delivering

the full range of broadband services can be deployed

quickly and inexpensively

by John Skoro

The past decade has seen explosive innovation by the telecommunications industry as it strives to satisfy a worldwide appetite for greater bandwidth. Several developments are fueling this growth—the proliferation of the Internet, increased dependence on data and a global trend toward deregulation of the industry.

Nowhere is the phenomenon more evident than in the quest to alleviate the local-loop bottleneck. This constriction occurs where local-area networks, which link devices within a building or a campus, join to wide-area networks, which criss-cross countries and hold the Internet together.

Advances in fiber technology have extended the capacity of wide-area networks to trillions of bits per second. Meanwhile local-area networks are evolving from 10 megabits per second (Mbps) to gigabits per second. The connections between these two domains have not kept pace, the vast majority of copper-wire circuits being limited to about the 1.5 Mbps rate of a so-called T1 line. The typical home user faces a more extreme case of the same affliction, with data crawling between computer and Internet about 30 times slower, through a modem and phone line operating at a mere 56 kilobits per second (kbps).

Of the variety of technologies developed for high-speed wireless access, local multipoint distribution service (LMDS) offers an ideal way to break through the local-access bottleneck. Like cell phone networks, LMDS is a wireless system but is designed to deliver data through the air at rates of up to 155 Mbps (typical cell phone voice calls use a mere 64 kbps, or 8 kbps in compressed digital systems). LMDS may be the key to bringing multimedia data to millions of customers worldwide. It supports voice connections, the Internet, videoconferencing, interactive gaming, video streaming and other high-speed data applications.

A major advantage of LMDS technology is that it can be deployed quickly and relatively inexpensively. New market entrants who do not have the luxury of an existing network, such as the copper wires or fiber of incumbent operators, can rapidly build an advanced wireless network and start competing. LMDS is also attractive to incumbent operators who need to complement or expand existing networks. For example, operators who are setting up a service primarily based on digital subscriber lines but who want their service to be universally available could use LMDS to fill in gaps in their coverage. And while cable modems are making inroads in the residential and home-office markets, the business market (where little to no cable network exists) remains a prime niche for LMDS.

The higher capacity of LMDS is possible because it operates in a large, previously unallocated expanse of the electromagnetic spectrum. In the U.S. the Federal Communications Commission has auctioned to LMDS operators a total bandwidth of about 1.3 gigahertz (GHz) in the “millimeter” waveband at frequencies of about 28 GHz. In other countries, depending on the local licensing regulations, broadband wireless systems operate at anywhere from 2 to 42 GHz. Canada, which is actively setting up systems around the country, has 3 GHz of spectrum set aside for local multipoint communications systems, as it is called there. Regular digital cell phone systems operate at about 0.8 GHz with a typical bandwidth allocation of 30 MHz or less.