首页
外语
计算机
考研
公务员
职业资格
财经
工程
司法
医学
专升本
自考
实用职业技能
登录
考研
Until recently, mobile radio was to wireless communications what the Yugo was to transportation. With a mixed clientele ranging
Until recently, mobile radio was to wireless communications what the Yugo was to transportation. With a mixed clientele ranging
admin
2009-04-26
28
问题
Until recently, mobile radio was to wireless communications what the Yugo was to transportation. With a mixed clientele ranging from truckers using CBs to police armed with walkie-talkies to taxi drivers dispatched by radio, it was viewed as an unglamorous business and a technological backwater.
But specialized mobile radio, as it is known, has been rediscovered. It is now considered one of the biggest prizes in the all-out war for the public airwaves. The reason: high-tech companies have figured out how to profitably rebuild the antiquated dispatching system into an advanced cellular-telephone network that can take on the likes of AT&T and the giant Baby Bells. Upstart Nextel Communications sent shock waves through the industry last week when it agreed to buy Motorola’s SMR frequencies for $1.8 billion.
That could pose a serious threat to cellular hegemony. Although both systems are based on the same basic technology, SMR systems are digital and cover almost 25 times as much area as the average cellular network. SMR handsets won’t work on cellular systems and tend to be bulkier than cellular phones, though they provide more features, like a digital pager service. And while cellular growth has tripled to some 13 million subscribers since 2000, the technology has been losing ground. It is running out of channel capacity so fast, in fact, that 40% of cellular calls in high-density areas like Manhattan and Los Angeles fail to be completed. SMRs have capacity to spare, and service could eventually be priced 10% to 15% less than cellular. Dispatchers predict they will have at least 10 million subscribers by the end of the decade. There are now about 1.5 million users of SMRs.
The addition of another contender to an already crowded field of telephone systems will surely multiply the confusion. By the year 2010, consumers will be able to choose from at least half a dozen vendors of a dizzying array of wireless-communications services, including pagers, voice mail answering machines and cellular phones. Phone and cable television operators, such as Bell South, MCI and Cox Enterprises, are developing so-called personal communications networks, or PCNs, a highly advanced portable-phone system that is expected to cover a wider area, connect to a greater variety of services and be cheaper to operate than conventional cellular.
And many companies that have gambled on the wrong technological standards, and invested billions trying to develop the same markets, will undoubtedly lose a great deal of money before the shakeout is over. "The winners", says Nextel chairman Morgan O’Brien, "will be those who can make the choice for consumers easy". With all the anticipated confusion—mindful of the early years of personal computers—it is likely to be years before anyone calls the purchase of wireless products an "easy" choice.
选项
A、Its technological features have radically changed.
B、It has been rebuilt to cater to various subscribers.
C、Its dimensions have been reduced by wide margins.
D、It was connected to a greater variety of services.
答案
A
解析
转载请注明原文地址:https://kaotiyun.com/show/Iha4777K
0
考研英语一
相关试题推荐
LightninghasbeenthesecondlargeststormkillerintheUSoverthepast40yearsandis______onlybyflood.
TheInternetaffordsanonymitytoususers,ablessingtoprivacyandfreedomofspeech.Butthatveryanonymityisalsobehind
Readthefollowingtextandchoosethebestanswerfromtherightcolumntocompleteeachoftheunfinishedstatementsinthele
Readthefollowingtextandchoosethebestanswerfromtherightcolumntocompleteeachoftheunfinishedstatementsinthele
Writeanessaybasedonthefollowinggraphexplainingtheupgradingofmassentertainmenttransformationbroughtaboutbythei
KimiyukiSudashouldbeaperfectcustomerforJapan’scar-makers.He’sayoung,successfulexecutiveatanInternet-servicesco
Musicisamystery.Itisuniquetothehumanrace:nootherspeciesproduceselaboratesoundfornoparticularreason.Ithasb
Musicisamystery.Itisuniquetothehumanrace:nootherspeciesproduceselaboratesoundfornoparticularreason.Ithasb
We’refairlygoodatjudgingpeoplebasedonfirstimpressions,thinslicesofexperiencerangingfromaglimpseofaphototoa
随机试题
身段表情是指与一定情绪状态相联系的躯干或四肢的动作变化。根据上述定义,下列属于身段表情的是:
是函数f(x)在点x=x0处连续的()
患者,男,51岁。有慢性咳喘病史10余年,平素易汗出,劳动后尤甚,易外感,体倦乏力,恶风,舌苔薄白,脉细弱。该患者治疗首选
有位商人外出经商多年不归。他妻子因思念丈夫,致胸脘痞满,不思饮食,倦怠乏力,日渐消瘦。某医诊治后,其父高声责骂她,女子无故被骂,既气又怒,放声大哭。大哭后渐有食欲,开始进食,病情好转。按照七情致病特点,请回答下列问题:其所致气机紊乱是
当事人对人民法院委托的鉴定部门作出的鉴定结论有异议申请重新鉴定,提出证据证明存在下列情形之一的,人民法院应予准许:()
甲、乙、丙、丁、戊公司均为增值税一般纳税人,适用的增值税税率为17%,2014年12月31日,甲公司资产负债表有关项目期末余额为:货币资金项目18500万元,应收账款项目3600万元,预收款项项目800万元,应交税费项目100万元,12月份相关交易事项
A、 B、 C、 D、 D第一套图黑点全在里面,第二套图黑点全在外面。
技术壁垒是商品进口国在实施贸易进口管制时,通过颁布法律、法令、条例、规定、建立技术标准、认证制度、卫生检验检疫制度、检验程序以及包装、规格标签和标准等,提高对进口产品的技术要求,增加进口难度,最终达到限制进口、保障国家安全、保护消费者利益和保持国际收支平衡
唐朝有关亲属相奸的内容规定在()。
A、0.B、一∞.C、+∞.D、不存在但也不是∞.D因为et=0,故要分别考察左、右极限.由于因此应选D.
最新回复
(
0
)