【正文】 原稿 出處： William Enck、 Patrick Traynor、 Patrick McDaniel and Tho mas La Porta。 在接收短信時(shí)，要對傳入數(shù)據(jù)包的內(nèi)容檢錯(cuò)，必要時(shí)，轉(zhuǎn)換成短信的格式并復(fù)制。移動(dòng)交換中心 除了呼叫路由外，還有移動(dòng)設(shè)備的認(rèn)證，本地基站的管理，網(wǎng)路切換和充當(dāng)連 接公眾交換電話網(wǎng)絡(luò)的網(wǎng)關(guān)等功能。因此，所有連接網(wǎng)絡(luò)的移動(dòng)設(shè)備周期性地檢測公用控制信道上的語音和 SMS 信號(hào)。 空中接口交付的最后階段見圖 。由于業(yè)務(wù)信道漸漸達(dá)到飽和，基于語音電話服務(wù)就變得毫無價(jià)值，然而，即使在最擁擠的地區(qū)，短信仍然能被成功接收，因?yàn)槎绦攀褂每刂菩诺?，它并不擁塞，因此，短信傳送仍然有效? 在討論任何有關(guān)移動(dòng)網(wǎng)絡(luò)攻擊的具體情況時(shí)，必需要從對手的角度來審視這些系統(tǒng)。 我們通過系統(tǒng)的傳輸協(xié)議、傳輸速率和接口特性來度量系統(tǒng)的特征。由于實(shí)際條件的限制，每個(gè) SMSC 的只有隊(duì)列的每個(gè)用戶的郵件數(shù)量有限。而對 Verizon 公司的短消息服務(wù)中心測試的結(jié)果不一樣。在這種情況下，與 全球移動(dòng)通信系 統(tǒng) 的標(biāo)準(zhǔn)一樣，移動(dòng)手機(jī)會(huì)從歸屬位置寄存器返回一個(gè)基站緩存溢出標(biāo)志。 畢業(yè)設(shè)計(jì)（論文） 外文翻譯 6 Exploiting Open Functionality in SMSCapable Cellular Networks 1． SMS/CELLULAR NETWORK OVERVIEW This section offers a simpli?ed view of an SMS message traversing a GSMbased system from submission to delivery. These procedures are similar in other cellular works including CDMA. Submitting a Message There are two methods of sending a text message to a mobile device via another mobile device or through a variety of External Short Messaging Entities (ESMEs). ESMEs include a large number of diverse devices and interfaces ranging from and webbased messaging portals at service provider websites to voic services, paging systems and software applications. Whether these systems connect to the mobile phone work via the Inter or speci?c dedicated channels, messages are ?rst delivered to a server that handles SMS traf?c known as the Short Messaging Service Center (SMSC). A service provider supporting text messaging must have at least one SMSC in their work. Due to the rising popularity of this service, however, it is being increasingly mon for service providers to support multiple SMSCs in order to increase capacity. Upon receiving a message, the contents of ining packets are examined and, if necessary, converted and copied into SMS message format. At this point in the system, messages from the Inter bee indistinguishable from those that originated from mobile phones. Messages are then placed into an SMSC queue for forwarding. Routing a Message The SMSC needs to determine how to route messages to their targeted mobile devices. The SMSC queries a Home Location Register (HLR) database, which serves as the permanent repository of user data and includes subscriber information (. call waiting and text messaging), billing data, availability of the targeted user and their current location. Through interaction with other work elements, the HLR determines the routing information for the destination device. If the SMSC receives a reply stating that the current user is unavailable, it stores the text message for later delivery. Otherwise, the response will contain the address of the Mobile Switching Center (MSC) currently providing service. In addition to call routing, MSCs are responsible for facilitating mobile device authentication, location management for attached base stations (BS), performing handoffs and acting as gateways to the Public Switched Telephone Network (PSTN). 畢業(yè)設(shè)計(jì)（論文） 外文翻譯 7 When a text message arrives from the SMSC, the MSC fetches information speci?c to the target device. The MSC queries a database known as the Visitor Location Register, which returns a local copy of the targeted device’s information when it is away from its MSC then forwards the text message on to the appropriate base station for transmission over the air interface. A diagram of a mobile phone work is depicted in Figure , followed by a simpli?ed SMS message ?ow in Figure . Figure SMS Network Figure Simplified examples of an SMS Network and message flow Wireless Delivery The air interface is divided into two parts the Control Channels (CCH) and Traf?c Channels (TCH). The CCH is further divided into two types of channels the Common CCH and Dedicated CCHs. The Common CCH, which consists of logical channels including the Paging Channel (PCH)