- 10.1.1 The Challenge of Securing XG. - 10.5.1 The Provable Security Paradigm. - 12.4.8 Fitzgerald et al.: The Marmot Java Compiler. - In the end, one must understand and be prepared to deal with the requirements of the application and the user who uses it.. - In December 2004, a tsunami swept hundreds of thousands of people – we may never really know how many – to their deaths, and the Internet community asked “how might we have helped?” The answer turns out to use interesting aspects of both types of communication systems. - Many of those would be by Internet – the web, RSS feeds, authenticated electronic mail, and so on. - Emerging standards provide a comprehensive and commercially neutral indication of the most likely direction of mobile systems in the medium term (five to six years). - This refers to a subset of the “Next-generation Mobile System” defined above. - This is the radio/wireless network connecting the user terminal to the edge of the core network.. - Chapter 2 deals with the architectural aspects of the push toward a commercially viable next generation (XG) mobile network. - This chapter provides a brief introduction to each of the XG system imperatives. - Packet-switched networks were overlaid onto many of the 2G networks, in the middle of the 2G period. - E-mail: This is a killer application regardless of the mobile network generation. - As described in the introduction, a full integration of the Internet with wireless networks is a XG mobile system imperative. - To be precise, the problem is the limited bandwidth of the wireless access networks. - On top of the network infrastructure is a service platform, which is used for creating services. - Figure 2.1 shows the very high level organization of the UMTS network.. - Figure 2.2 presents a more detailed view of the network architecture. - A brief description of different subsystems follows, starting from the mobile station (MS), shown at the bottom of the figure. - The IuCS and IuPS interfaces connect all mobiles in the access network to the CS and PS domains of the CN respectively.. - This separation makes the core network somewhat independent of the bearer technology. - The PS domain consists of the GPRS support nodes, which are counterparts to the MSC in the CS domain;. - Figure 2.4 contains a diagram of the PDP context.. - Figure 2.5 shows some components of the IP multimedia subsystem. - Classmark 2 is a PersonalJava 4 device with the addition of the JavaPhone API 5 . - The latter consists of the packet control function (PCF), packet data support node (PDSN), mobile endpoint home agent (HA), and an authentication, authorization, and accounting (AAA) function. - The Service Transfer Point (STP) is a packet switch (not shown, but resides in the SS7 network) that connects the different components of the network.. - The tension between the smart core and the dumb core has been widely debated (Isenberg 1997) and is one of the key decisions in the architecture. - The so-called next-generation network (NGN) designs of the 1990s (Jain et al. - openness of the core elements (routers), and the attractive economics of computing at the edge of the network. - Figure 2.19 Schematic of the XG architecture. - Note that this diagram shows only one plane of the system.. - Figure 2.20 Layers and facets of the all-IP XG architecture. - Figure 2.21 shows a view of the architecture with an instantiation in terms of physical network and service elements. - Figure 2.21 An instantiation of the all-IP XG architecture. - For a detailed description of the IS-95 system, see (Garg 2000).. - These technologies are key to the success of the W-CDMA. - The output is a number of replicas of the transmitted QPSK symbol sequence. - Detecting the scrambling code mask timing of the best BS (determined using the least sum of propagation path loss plus shadowing). - Noticing that a lower-layer code can be expressed as an alternate combination of the. - Figure 3.17 illustrates an example of the structure of a Turbo encoder/decoder with a cod- ing rate of 1/3. - In the inner-loop operation, BS measures the SIR of the output from the Rake combiner.. - Let (s) b,l be the estimated received signal of the l-th (l = 1, 2. - The structure of the CEIGU is illustrated in Figure 3.23.. - The advantage of the Type-II HARQ is not obvious. - One of the most significant concerns in the uplink scheme design is the power con- sumption limit of mobile handsets (Sawahashi et al. - Details of the 2D spreading principle (Atarashi et al. - Figure 3.30 also shows the corresponding example of the OVSF scheme.. - Figure 3.32 shows the configuration of the VSF-OFCDM transmitter.. - SF is determined by the symbol rate of the physical channel. - Figure 3.34 shows a conceptual diagram of the VSCRF-CDMA scheme.. - The following subsections provide a brief outline of the MAC and PHY technologies in the WLAN standard. - Distributed Coordination Function (DCF) and Point Coordination Function (PCF) The distributed coordination function (DCF) is a contention-based function of the IEEE 802.11 MAC. - and Slot time is the value of the corresponding PHY characteristic. - The IFS is a time interval after a busy state of the channel. - Figure 4.9 shows the time chart of the CSMA/CA with RTS- CTS handshaking.. - This is one of the fundamental problems of broadband wireless access. - OFDM is one of the most spectrum-efficient multicarrier transmission methods.. - The multipath effect of the GI is shown in Figure 4.12. - This option would decrease installation costs for WLAN hotspots of the next generation.. - For details of the research, see (Gwon et al. - A new QoS enhancement of the IEEE 802.11 WLAN standard includes three features that support real-time applications:. - Local movement: Movement within the PHY range of the communicating stations (STAs), that is, movement within a Basic Service Set (BSS). - On the basis of the AP’s neighborhood graph, these methods are improved and the target APs are clearer. - The creation of the handoff key is illustrated in Figure 4.25. - This section provides an overview of the latest information on the IEEE 802.11e standard.. - This multiple frame exchange support is possible because of the TXOP. - On the basis of the admission control policy, the HC either accepts or rejects the request. - Another new feature of the IEEE 802.11e standard is the Direct Link Protocol (DLP). - The AS communicates with each STA implementing the IEEE 802.1X Supplicant through the Authenticator for mutual authentication of the AS and the STA. - The STA and the AP identify the RSNA capability on the basis of the RSN IE in the Beacon, Probe Response, and (Re)Association Requests.. - In this example, the EAP/TLS is used to have mutual authentication of the STA and the AS.. - On the basis of the PMK, the STA and the AP create a PTK after a four-way hand- shake. - Details of the TKIP and CCMP algorithms can be found in the IEEE 802.11i standard, which is expected to be published in mid 2004.. - Perhaps none of the Internet architectural principles is as misunderstood in the 3G mobile telephony community as the end-to-end principle. - The only failure that is acceptable for disrupting network service in the Internet is complete and total partitioning of the network.. - The routers that perform packet forwarding constitute the routing fabric of the Internet.. - In essence, the host is a leaf in the branching tree of the Internet.. - Local servers mirror some part of the global name space. - In order for packets to be able to reach the mobile host at its new care-of address, a router in the home network must be aware of the care-of address and ready to forward packets to the mobile host. - The source address of the packet is the correspondent host address, but the destination address is actually the address of the mobile host in the home network.. - Packets from the mobile host to the correspondent host must arrive at the correspondent host with the mobile host’s home address as the source address of the packet. - Figure 5.2 shows how packets get dropped prior to update of the home agent and correspondent host.. - The specified neighbor advertisement option is sent to the new router, either as part of the routing failure repair signaling or as a separate message, when the mobile host arrives on the new link. - Another issue in wireless link security is the security of the local link. - The home agent then performs the functions of the NAS. - The purpose of the home-address test message is to verify that the mobile host is, in fact, at the home address. - It is in this sense that the return routability procedure depends on the security of the routing infrastructure.. - These binding updates contain precise information about the topological location of the mobile host in the routing infrastructure. - In addition, if the interface identifier portion of an IPv6 address can be tied somehow to the owner of the mobile host (for example, through a telephone number), the identity of the user could be determined. - The exact location of the mobile host can be obscured, but not completely eliminated, by interposing a routing proxy between the mobile host and correspondent host. - During that time, the mobile host’s application protocols are not obtaining the full bandwidth of the link. - For Mobile IPv6, the primary function of the CARD protocol is to provide the mobile host with enough information to begin configuration of a care-of address prior to moving to the new subnet. - The mobile host can decide, on the basis of the characteristics, whether a router is a good choice for handover.. - The hardware and software implementation of the API is called the platform. - An API provides an abstract representation of the commands that the application can issue to the platform. - Interfaces 1 and 4 between the third-party applications and the framework provide the application with basic mechanisms (such as authentication, authorization, service discov- ery, service subscription, service negotiation, and integrity management) that enable the applications to make use of the service capabilities in the network. - The framework itself takes the role of the retailer of services.. - The application creates an instance of the Listener component to communicate with the Provider. - Enabler services can be accessed by a standardized interface in a way similar to the service components of the Parlay/OSA architecture.
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