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  3. Smartphones A smartphone is one device that

Smartphones A smartphone is one device that

游客2023-08-29  24
问题                                 Smartphones
    A smartphone is one device that can take care of all of your handheld computing and communication needs in a single, small package.
Basics of a Smartphone

    Unlike many traditional cell phones, smartphones allow individual users to install, configure(设定)and run applications of their choosing. A smartphone offers the ability to conform the device to your particular way of doing things. Most standard cell-phone software offers only limited choices for re-configuration, forcing you to adapt to the way it’s set up. On a standard phone, whether or not you like the built-in calendar application, you are stuck with it except for a few minor adjustments. If that phone were a smartphone, you could install any compatible calendar application you like.
    Since cell phones and PDAs are the most common handheld devices today, a smartphone is usually either a phone with added PDA capabilities or a PDA with added phone capabilities. Smartphones can do many things: sending and receiving mobile phone calls, Personal Information Management(PIM)including notes, calendar and to-do list, communication with laptop or desktop computers, data synchronization(同步)with applications like Microsoft Outlook and Apple’s iCal calendar programs, E-mail, instant messaging, and playing audio and video files in some standard formats.
    Future applications promise to be even more impressive. For example, the Nokia 613li is a phone utilizing near field communication(NFC)to allow the phone to act as a wireless credit card. The phone uses a two-way communication system to transfer payment information to pads at certain retail stores. Currently, it’s still in the trial phase of development.
Network Protocols
    Smartphones use cell-phone network technology to send and receive data(such as phone calls, web browsing, file transfers, etc.). Developers classify this technology into generations. The first generation includes analog(模拟)cell phone technology. Digital cell phones require more advanced protocols, which constitute the second generation. Between generation two and three, network engineers created protocols that are more advanced than generation two’s digital technology but not so innovative that they are a truly new generation. Developers refer to these protocols as generation 2. 5. This generation includes several early smartphone protocols, some of which are still used today.
    General Packet Radio Services(GPRS)is a wireless, packet-based communication service and until recently was the standard 2. 5G protocol used in most smartphones. Unlike a circuit-switched voice connection, this is a packet-switched, "always on" connection that remains active as long as the phone is within range of the service. It allows smartphones to do things like run applications remotely over a net-work, interface with the Internet, participate in instant messenger sessions, act as a wireless modem for a computer and transmit and receive e-mails.
Flexible Interfaces
    The core services on smartphones all tie in to the idea of a multi-purpose device that can effectively multitask. A user can watch a video clip, field a phone call, then return to the video clip after the call, all without closing each application. Or he or she can flip through the digital calendar and to-do list applications without interrupting the voice call. All of the data stored on the phone can be synchronized with outside applications or manipulated by third-party phone applications in any number of ways.
    Systems supported by smartphones include Bluetooth, a short-range, wireless radio service that allows phones to wirelessly link up with each other and with other nearby devices that support it. This includes things like printers, scanners, input devices, computers and headsets. Some varieties of Bluetooth only allow communication with one device at a time, but others allow simultaneous connection with multiple devices.
    Also included is data synchronization. The phone keeping track of your personal information, like appointments, to-do lists, addresses, and phone numbers, needs to be able to communicate with all of the other devices you use to keep track of those things. There are hundreds of possible platforms and applications you might use for this in the course of a day. If you want to keep all of this data in synchronization with what’s on your phone, then you generally have to look for a cell phone that speaks the languages of all of the devices and applications you use. Or you can go out and buy new applications that speak the language of your cell phone.
    Then there is Open Mobile Alliance(OMA), a collaborative organization with the mission to "facilitate global user adoption of mobile data services by specifying market-driven mobile service enablers that ensure service interoperability(互用性)across devices, geographies, service providers, operators, and networks, while allowing businesses to compete through innovation and differentiation". The OMA formed a Data Synchronization Working Group, which is continuing the work begun by the SyncML Initiative. SyncML is an open-standards project designed to eliminate the trouble of worrying about whether your PIM(个人信息管理)devices sync up with your phone and vice-versa(反过来也一样). The project is designed so that any kind of data can be synchronized with any application on any piece of hardware, through any network, provided that they are all programmed to OMA standards. This includes synchronization over the Web, Bluetooth, mail protocols and TCP/IP networks.
The Future of Smartphones
    Smartphones are getting thinner and cheaper, and as a result are entering the consumer market. Analysts predict that one billion smartphone handsets will be sold by 2011.
    Perhaps the most challenging consideration for the future is security. Smartphones and PDAs are already popular among many corporate executives, who often use their phones to transmit confidential information. Smartphones may be vulnerable to security breaches such as an Evil Twin attack. In an evil twin attack, a hacker sets a server’s service identifier(标识符)to that of a legitimate hotspot or network while simultaneously blocking traffic to the real server. When a user connects with the hacker’s server, information can be tapped and security is compromised.
    One downside to the openness and configurability(可配置性)of smartphones is that it also makes them susceptible to viruses. Hackers have written viruses that attack SymbianOS(操作系统)phones. The viruses can do things like turning off anti-virus software, locking the phone completely or deleting all applications stored on the phone.
    On the other side, some critics argue that anti-virus software manufacturers greatly exaggerate the risks, harms and scope of phone viruses in order to help sell their software.
    The incredible diversity in smartphone hardware, software and network protocols restrain practical, broad security measures. Most security considerations either focus on particular operating systems or have more to do with user behavior than network security.
    With data transmission rates reaching fast speeds and the incorporation of WiFi(无线局域网)technology, the sky is the limit on what smartphones can do. Possibly the most exciting thing about smartphone technology is mat the field is still wide open. It’s an idea that probably hasn’t found its perfect, real-world implementation yet. Every crop of phones brings new designs and new interface ideas. No one developer or manufacturer has come up with the perfect shape or size yet. The next generation smartphone could look like a flip phone, a tablet PC, a candy bar or something no one has conceived of yet. [br] According to developers, analog cell phone technology belongs to______.
选项 A、generation 1
B、generation 2. 5
C、generation 3
D、generation 2
答案 A
解析 文中说研发人员将传输和接收数据的技术分为几代，其中模拟数字技术是第一代，故选[A]。
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