CR系统用成像板(IP)来接收X线的模拟信息，然后经过模／数转换来实现影像的数字化。对IP的曝光过程就是信息采集。

关于IP的叙述错误的是

A:IP作为辐射接收部件替代了常规X线摄影用的胶片 B:IP在X线下受到第一次激发时储存连续的模拟信息 C:IP被扫描后所获得的信息可以同时进行存储和打印 D:曝光后的成像板，由于吸收X线而发生电化学反应 E:IP的影像数据可通过施加强光照射来消除

目前最流行的 IP传送技术有三种，即 IP Over ATM、________和IP Over WDM。

IP Over SDH

目前最流行的IP传送技术有（ ）。

A:IPOver ATM B:IP Over WDM C:IP Over SDH D:IP Over RPR

目前最流行的IP传送技术有三种，即IP Over ATM、 (　)和IP Over WDM。

A:IP Over VSAT B:IP Over CATV C:IP Over SDH D:IP Over EDFA

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 。

To satisfy the users QoS requirements, the network architecture design should include (　).

A:Voice -over -IP B:the quality mechanism C:workload D:Video-on-Demand