C.DBMS包括DB和DBS D.DBS与DB和DBMS无关
89、数据库系统中，DBA使用的数据视图用（A）描述。 A.外模式 B.内模式 C.存储模式 D.概念模式
90、分布式数据库中的数据操作的原子性指的是（C）。 A.当多个用户访问同一数据的不同副本时，有完全相同的视图
B.需要在多个节点上完成的操作必须全部提交，若有一个节点提交失败必须全部撤销 C.数据存放在不同节点上，这些节点不共享磁盘，但逻辑上属于同一个整体 D.数据存放的节点以及数据存放的物理细节等对用户是透明的
91-92、在通信专业中，TCP的英文全称是（D），“认证”英文通常翻译为（A）。 A.Transmission Control Process B.Transfer Control Protocol
C.Transmission Connecting Protocol D.Transmission Control Protocol
A.authentication B.authorization C.control D.encryption
93、802.11n is a WLAN standard approved by the （B）, which can be used ti support data rate uo to 600Mbps. A.IEIF B.IEEE C.ITU D.ISO
94、The VoIP gateway can perform the digitization, （D） and encapsulation required, and it controls the setup of VoIP calls between the calling device and the called device. A.amplification B.depression C.radiation D.compression
95、To maintain a telephone conversation over the Internet. The voice packets must arrive at their destination in （A）. A.a continuous stream B.a burst stream C.a delayed stream D.a burst mode
96-97、A Next Generation Network(NGN) is a （D） network ,which is able to provide Telecomunication Services ti users and to make use of multiple broadband, QoS-enable transport technologies and in which service-related functions are （B） of the underlying transport-related technologies. A.ISDN B.ATM C.circuit-based D.packet-based
A.dependent B.independent C.related
D.depend
97-100、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 （A） in conventional cellular communication networks, Because of （A）, 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 （B）. A.better than B.maturer than C.as good as D.not as good as
A.the different network administrative domains
B.the same network administrative domains and mobile users C.mobile users
D.the same network administrative domains
A.Voice -over -IP B.the quality mechanism
C.workload
D.Video-on-Demand
