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One cell has 2 TRXs （14 timeslots used for TCH).How many Erlang can this cell carry if t

One cell has 2 TRXs (14 timeslots used for TCH).How many Erlang can this cell carry if the QoS (blocking rate) is 2%？（）

A.2.7 Erlang

B.8.2 Erlang

C.16.0 Erlang

D.14.0 Erlang

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更多“One cell has 2 TRXs （14 timesl…”相关的问题

第1题

Which of the following statements is incorrect？（)

A.One TG consists of up to 16 TRXs

B.One TG can be connected to a maximum of 32 cells

C.A cell can be connected to one only

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第2题

Use the enclosed Erlang Table to work out which is the optimum SDCCH configuration usi

ng four TRXs, if the SDCCH/TCH traffic ratio is 30% and the required GoS on the TCH is 2%. (Assume no cell broadcast and no immediate assignment on the TCH.)()

A.SDCCH/8

B.SDCCH/8 + SDCCH/4

C.2*SDCCH/8

D.2*SDCCH/8 + SDCCH/4

E.3*SDCCH/8

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第3题

AT&T plans to spend 18 billion dollars in 2010【D1】______ its wireless networks to 【D2】

______the increasing amount of new traffic. This is roughly $2 billion more than the company had 【D3】______ in the previous year. Specifically, AT&T will add 2, 000 new cell sites and upgrade existing cell sites with three times more fiber links than it had in 2009. This will increase【D4】______ to connect the cell towers to AT&Ts main network. AT&T, which is the only wireless【D5】______ in the US selling the iPhone, has been the【D6】______of much criticism over this past year, as many iPhone 【D7】______, particularly in densely populated urban areas, have【D8】______ about dropped calls, slow Internet access, and poor service. Some critics claim the company has not been spending enough on network upgrades to【D9】______ with growing demand. AT&T has【D10】______ that it has faced some difficulties, particularly in big cities. But the company is "closing the gap".

【D1】

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第4题

Cells have several ways of ensuring that their daughters remember what kind of cells they should be. How do differentiated cells maintain their identity？

A．One of the simplest and most important is through a positive feedback loop, where a master transcription regulator activates transcription of its own gene,in addition to that of other cell-typespecific genes. Each time a cell divides, the regulator is distributed to both daughter cells, where it continues to stimulate the positive feedback loop.？The continued stimulation ensures that the regulator will continue to be produced in subsequent cell generations.？Positive feedback is crucial for establishing the “self-sustaining” circuits of gene expression that allow a cell to commit to a particular fate—and then to transmit that decision to its progeny.

B．Although positive feedback loops are probably the most prevalent way of ensuring that daughter cells remember what kind of cells they are meant to be,there are other ways of reinforcing cell identity. One involves the methylation of DNA．In vertebrate cells, DNA methylation occurs on certain cytosine bases. This covalent modification generally turns off the affected genes by attracting proteins that bind to methylated cytosines and block gene transcription. DNA methylation patterns are passed on to progeny cells by the action of an enzyme that copies the methylation pattern on the parent DNA strand to the daughter DNA strand as it is synthesizeD

C．Another mechanism for inheriting gene expression patterns involves the modification of histones. When a cell replicates its DNA,each daughter double helix receives half of its parent’s histone proteins, which contain the covalent modifications that were present on the parent chromosom

E．Enzymes responsible for these modifications may bind to the parental histones and confer the same modifications to the new histones nearby. It has been proposed that this cycle of modification helps reestablish. the pattern of chromatin structure found in the parent chromosome

D．Because all of these cell-memory mechanisms transmit patterns of gene expression from parent to daughter cell without altering the actual nucleotide sequence of the DNA,they are considered to be forms of epigenetic inheritanc

E．These mechanisms, which work together, play an important part in maintaining patterns of gene expression, allowing transient signals from the environment to be remembered by our cells—a fact that has important implications for understanding how cells operate and how they malfunction in diseas

E．

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第5题

一个ULTRASITE机架最多能带（）个TRXS

A.1

B.2

C.6

D.12

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第6题

【A popular service that has attercted the interest of companies and has home users alike i

s the sending of voice signals over an IP-based network, such as the Internet. The practice of making telephone calls over the internet has had a number of different names, including packet voice, voice over packet, voice over the internet, internet telephone, and Voice over Ip（Voip）. But it appears the industry has settled on the term”Voice ove IP” in reference to the internet protocol, which controls the transfer of data over the internet. There are currently three ways to deliver VoIp to users, the first technique is found at the corporate level. Many companies are offering VoIP systerms that operate over a local area network. These systems involve a fair amount of equipment, such as VoIP servers, special IP-enabled telephones, and routers that can direct telephone calls. Today a large portion of corporate sites have converted their older internal telephone systems to VoIP systems that opreate over a LAN, thus converging two systems into one. A second common solution is the one often encountered at home. Using existing telephones, a special converter is added between the telephone and a high speed internet（DSL or cable modem）connection. The converter digitizes the voice signal and creates a stream of packets that are then sent over an ip connection.The third technique involves smart cell phones. Never cell technologies are all packet-based, thus requiring a telephone call to be converted to digital packets and sending those packets over IP networks.】

From the paragraph above，a popular service that has attracetd the interest of companies and home users,is termed as （） . The data transfer over the Internet is controlled by the （） . At corporate level, many companies have replaced their older internal telephone systerms with （） that oprerate over a local area network.

A、voice over the internet B、voice over packet C、Voice over IP D、internet telephony A、packet B、internet protocol C、industry D、VoIp servers A、VoIP systems B、IP-enablde telephones C、VoIP servers D、routers

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第7题

Shortages of flu vaccine are nothing new in America, but this year' s is a whopper. Until

last week, it appeared that 100 million Americans would have access to flu shots this fall. Then British authorities, concerned about quality-control problems at a production plant in Liverpool, barred all further shipments by the Chiron Corp. Overnight, the U.S. vaccine supply dwindled by nearly half and federal health officials found themselves making an unusual plea. Instead of beseeching us all to get vaccinated, they' re now urging most healthy people between the ages of 2 and 64 not to. "This reemphasizes the fragility of our vaccine supply," says Dr. Martin Myers of the National Network for Immunization Information, "and the lack of redundancy in our system."

Why is such a basic health service so easily knocked out？ Mainly because private companies have had little incentive to pursue it. To create a single dose of flu vaccine, a manufacturer has to grow live virus in a 2-week-old fertilized chicken egg, then crack the egg, harvest the virus and extract the proteins used to provoke an immune response. Profit margins are narrow, demand is fickle and, because each year's flu virus is different, any leftover vaccine goes to waste. As a result, the United States now has only two major suppliers (Chiron and Aventis Pasteur)--and when one of them runs into trouble, there isn' t much the other can do about it. "A vaccine maker can't just call up and order 40 million more fertilized eggs," says Manon Cox, of Connecticut-based Protein Sciences Corp. "There's a whole industry that's scheduled to produce a certain number of eggs at a certain time. "

Sleeker technologies are now in the works, and experts are hoping that this year's fiasco will speed the pace of innovation. The main challenge is to shift production from eggs into cell cultures--a medium already used to make most other vaccines. Flu vaccines are harder than most to produce this way, but several biotech companies are now pursuing this strategy, and one culture-based product (Solvay Pharmaceuticals' Invivac) has been cleared for marketing in Europe.

For Americans, the immediate challenge is to make the most of a limited supply. The government estimates that 95 million people still qualify for shots under the voluntary restrictions announced last week. That' s nearly twice the number of doses that clinics will have on hand, but only 60 million Americans seek out shots in a normal year. In fact, many experts are hoping the shortage will serve as an awareness campaign--encouraging the people who really need a flu shot to get one.

Shortages of flue vaccine show that ______.

A．America relies too much on foreign suppliers

B．the demand of flue vaccines is high this year

C．quality problem is a serious problem in flu vaccine production

D．the supply of flu vaccines is rather weak and America has no back-up measures to make it up

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第8题

Being fat is bad for you.【B1】______that, almost everyone agrees. It is just possible,【B2】_

_____, that almost everyone is wrong. In fact, getting fat may be a mechanism that【B3】______the body. The health problems【B4】______with fatness may not be caused by it but be another【B5】______, another symptom, of overeating. That is the【B6】______of Roger Unger and Philip Scherer. Dr. Unger and Dr. Scherer have been reviewing the science of what has come to be known as metabolic syndrome. This is a cluster of symptoms such as high blood【B7】______, insulin resistance and fatness that seem to increase the【B8】______of heart disease and strokes, diabetes and liver disease. "Syndrome" is the medical term for a(n) 【B9】______of symptoms whose common cause is not【B10】______understood. The symptom of metabolic syndrome that appears first is usually【B11】______, so this is generally【B12】______as the underlying cause. Dr. Unger and Dr. Scherer,【B13】______, turn this logic on its head. They point out that there is usually a period of many years between a person becoming【B14】______and his developing the other【B15】______. If the growth of adipose tissue(the body cells in which fat is stored)were【B16】______harmful, that would not be the【B17】______. This is one of the lines of evidence that has led them to the conclusion that,【B18】______its role in storing energy as a hedge against future famine, getting fat is a protective mechanism【B19】______metabolic syndrome. Their thesis is that lipids(the group of molecules that includes fats), which are needed in small amounts to make cell membranes, are toxic in larger quantities.【B20】______them into adipose tissue is one of the bodys ways of dealing with that toxicity.

【B1】

A．In

B．At

C．With

D．On

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第9题

Generation N is also challenging society’s traditional ideas about love, marriage and

children. Researchers __(1)__ that Gen N’s are more individualistic. They want their own personal space and freedom. This is resulting __(2)__ many people choosing to marry later, or not at all. One marketing and research company discovered the__(3)__attitude among Gen N’s: There’s no need to marry if you can lead a happy and independent life __(4)__ . For those __(5)__ do marry, they’re waiting until they’re older. They’re also choosing to have children later. Many Gen N’s come __(6)__ homes where both parents work. This has made them the generation with more disposable income than any other. And marketers haven’t lost __(7)__ of this fact. These days, __(8)__ from cell phones to credit cards is marketed directly toward Generation N. As a group, they enthusiastically welcome rapidly changing technology. And they eagerly buy and use the newest products. Unfortunately, Gen N’s also have a great willingness to buy on credit. They worry __(9)__about going __(10)__ debt than previous generations.

(1)、A、said

B、says

C、stated

D、state

(2)、A、in

B、to

C、for

D、from

(3)、A、followed

B、follows

C、following

D、follow

(4)、A、lonely

B、lone

C、alone

D、along

(5)、A、that

B、which

C、whom

D、who

(6)、A、from

B、in

C、out

D、of

(7)、A、view

B、sight

C、vision

D、idea

(8)、A、anything

B、nothing

C、something

D、everything

(9)、A、more

B、much

C、less

D、little

(10)、A、to

B、into

C、on

D、for

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第10题

第二篇Not content with its doubtful claim to produce cheap food for our own population, th

第二篇

Not content with its doubtful claim to produce cheap food for our own population, the factory farming industry also argues that "hungry nations are benefiting from advances made by the poultry(家禽) industry". In fact, rather than helping the fight against malnutrition(营养不良) in "hungry nations", the spread of factory farming has, inevitably aggravated the problem.

Large-scale intensive meat and poultry production is a waste of food resources. This is because more protein has to be fed to animals in the form. of vegetable matte than can ever be recovered in the form. of meat. Much of the food value is lost in the animal' s process of digestion and cell replacement. Neither, in the case of chicken, can one eat feathers, blood, feet or head. In all, only about 44% of the live animal fits to be eaten as meat.

This means one has to feed approximately 9～10 times as much food value to the animal than one can consume from the carcass. As a system for feeding the hungry, the effects can prove disastrous. At times of crisis, grain is the food of life.

Nevertheless, the huge increase in poultry production throughout Asia and Africa continues. Normally British or US firms are involved. For instance, an American based multinational company has this year announced its involvement in projects in several African countries. Britain's largest suppliers of chickens, Ross Breeder, are also involved in projects all over the world.

Because such trade is good for exports, Western governments encourage it. In 1979, a firm in Bangladesh called Phoenix Poultry received a grant to set up a unit of 6,000 chickens and 18,000 laying hens. This almost doubled the number of poultry kept in the country all at once.

But Bangladesh lacks capital, energy and food and has large numbers of unemployed. Such chicken-raising demands capital for building and machinery, extensive use of energy resources for automation, and involves feeding chickens with potential famine- relief protein food. At present, one of Bangladesh' s main imports is food grains, because the country is unable to grow enough food to feed its population. On what then can they possibly feed the chicken？

In this passage the author argues that______。

A. efficiency must be raised in the poultry industry

B. raising poultry can provide more protein than growing grain

C. factory farming will do more harm than good to developing countries

D. hungry nations may benefit from the development of the poultry industry

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