A station in the mobile service the emissions of which are i

With the explosive popularity of mobile devices, we have witnessed a steady increase in demand for mobile date service. In addition mobile users also expect to connect to the Internet for communicate and access to services through the best suitable connection, anywhere and at anytime. Although the seamless roaming capability is well supported in conventional. Cellular communication networks, roaming and interworking technologies are still immature in heterogenous wireless networks. Seamless roaming over heterogenous wireless networks will be an ongoing and improved process, due to the requirements from both end users and network administrators. From the wireless access networks belonging to different administrative domains, mobile users cannot always identify at every instance which network is the best one to access for their service. It is highly demanded to establish a network architecture which can facilitate mobile terminals to access the appropriate network in a cost-effective way. If a mobile user wants to move from one network to another with continuous service, the terminals have to cope with network change to maintain service seamlessly. Quality of service is a major issue that the end users should be provided with the satisfying service, while the network workload and cost should not too much increased. In addition, since end users are provided with numerous service ranging from Voice-over-IP to Video-on-Demand services, it is expected that users can experience the same quality for all the different service. Therefore, the network architecture need to be designed in such a way that the quality mechanism is incorporated so that users are served according to their individual QoS requirements. Based on the paragraph above, at present, seamless roaming over heterogenous wireless network is () in conventional cellular communication networks, Because of (), mobile users cannot always identify at every instance which network is the best one to access for their services. To satisfy the users QoS requirements, the network architecture design should include () A.better than

B.maturer than

C.as good as

D.not as good as

49.A.the different network administrative domains

B.the same network administrative domains and mobile users

C.mobile users

D.the same network administrative domains

50.A.Voice -over -IP

B.the quality mechanism

C.workload

D.Video-on-Demand

请帮忙给出每个问题的正确答案和分析，谢谢！

（ ）is a style of computing in which dynamically scalable and offer virtualized resources are provided as a service over the Internet.

A. Cloud computing B. Big dataC. Social media D. Mobile computing

Optimism and pessimism are both powerful __(1)__, and each of us must choose which we want to shape our outlook and our expectations. There is enough good and bad in everyone's life —ample sorrow and happiness, sufficient joy and pain—to find a rational basis for __(2)__ optimism or pessimism. It's ourdecision: __(3)__ which perspective do we want to view life? Will we look up in hope or down in __(4)__?

Years ago, I drove into a __(5)__ station to get some gas. As I walked into the station to pay for the gas, the attendant said to me, ―How do you feel?

That seemed like an odd question, but I felt fine and told him __(6)__ You don’t look well, he replied. This took me completely __(7)__surprise. A little less confidently, I told him that I had never felt better. Without hesitation, he__(8)__ to tell me how bad I looked and that my skin appeared yellow.__(9)__ the time I left the service station, I was feeling a little uneasy. About a block away, I pulled over to the side of the road to look at my face inthe mirror. Did I have a bad liver? By the time I got home, I was beginning to feel a little __(10)__. Had I picked up some rare disease?

(1)A、friends

B、forces

C、features

D、expectations

(2)A、neither

B、not

C、either

D、both

(3)A、In

B、According to

C、From

D、To

(4)A、joy

B、frustration

C、pain

D、despair

(5)A、railway

B、bus

C、broadcasting

D、service

(6)A、this

B、so

C、too

D、that

(7)A、by

B、in

C、to

D、for

(8)A、managed

B、tried

C、continued

D、wenton

(9)A、On

B、By

C、From

D、In

(10)A、sick

B、joyful

C、sad

D、great

CDMA for cellular system can be described as follows. As with FDMA, each cell is allocated a frequency （71） , when is split into two parts, half for reverse (mobile unit to base station) and half for （72） (base station to mobile unit). For full-duplex （73） , a mobile unit both reverse and forward channels. Transmission is in the form. of direct-sequence spread （74） , which used a chipping code to increase the data rate of the transmission, resulting is an increased signal bandwidth. Multiple access is provided by assigning （75） chipping codes to multiple users, so that the receiver can recover the transmission of an individual unit from multiple transmissions.

A.ware

B.signal

C.bandwidth

D.domain

All client computers on your company network run Windows 7 and are members of an Active Directory Domain Services domain. Your company policy requires that all unnecessary services be disabled on the computers. The Sales department staff has been provided with new mobile broadband adapters that use the Global System for Mobile Communications (GSM) technology. You need to ensure that portable computers can connect to the broadband GSM network. Which service should be enabled on the portable computers?（）

A.WLAN AutoConfig

B.WWAN AutoConfig

C.Computer Browser

D.Portable Device Enumerator Service

Most smart phones have（ ）service capabilities, which means that apps that combine the phone user&39;s location with the availability of retail stores and services can be interwoven into creative mobile business opportunities.

A. short messaging service B. global positioning satellite(GPS)C. online banking D. EDI

【An overall cellular network contains a number of different elements from the base transceiver station (BTS) itself with its antenna back through a base station controller (BSC), and a mobile switching centre (MSC) to the location registers (HLR and VLR) and the link to the public switched telephone network (PSTN). Of the units within the cellular network, the BTS provides the direct communication with the mobile phones. There may be a small number of base stations then linked to a base station controller. This unit acts as a small centre to route calls to the required base station, and it also makes some decisions about which of the base station is best suited to a particular call. The links between the BTS and the BSC may use either land lines of even microwave links. Often the BTS antenna towers also support a small microwave dish antenna used for the link to the BSC. The BSC is often co-located with a BTS. The BSC interfaces with the mobile switching centre. This makes more widespread choices about the routing of calls and interfaces to the land line based PSTN as well as the HLR and VLR.】 From the paragraph above, in a cellular network, the （98） can provide direct communication with a mobile phone, the （99） acts as a small centre to route calls to the required base station, and it also makes some decisions about which of the base station is best suited to a particular call.（100） can be used to link the BSC with related BTS。

A. BSC B. BTS C. MSC D. VLR A. BSC B. BTS C. MSC D. HLR A. Land lines B. Microwave links C. Microwave dish antenna D. Land lines or microwave links