摘要 :
B206 г. Минкомсвязи России были приняты нормативные правовые акты, позволяющие строить сети подвижной радиотелефонной связи на...
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B206 г. Минкомсвязи России были приняты нормативные правовые акты, позволяющие строить сети подвижной радиотелефонной связи на базе технологии LTEc предоставлением голосовых услуг и использованием нумерации телефонной сети общего пользования. Анализируются особенности построения сетей LTEна основе технологии IMS. Показано, что новые схемы построения позволяют достичь существенной экономии при строительстве опорной сети.
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There is currently a high level of consciousness of the importance and impact of formally testing communicating networks. By applying formal description techniques and formal testing approaches, we are able to validate the conform...
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There is currently a high level of consciousness of the importance and impact of formally testing communicating networks. By applying formal description techniques and formal testing approaches, we are able to validate the conformance of implementations to the requirements of communication protocols. In this context, passive testing techniques are used whenever the system under test cannot be interrupted or access to its interfaces is unavailable. Under such conditions, communication traces are extracted from points of observation and compared to the expected behavior formally specified as properties. Since most works on the subject come from a formal model context, they are optimized for testing the control part of the communication with a secondary focus on the data parts. In the current work, we provide a data-centric approach for black-box testing of network protocols. A formalism is provided to express complex properties in a bottom-up fashion starting from expected data relations in messages. A novel algorithm is provided for evaluation of properties in protocol traces. Experimental results on Session Initiation Protocol (SIP) traces for IP Multimedia Subsystem (IMS) services are provided.
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The third-generation partnership project (3GPP) and 3GPP2 have standardized the IP multimedia subsystem (IMS) to provide ubiquitous and access network-independent IP-based services for next-generation networks via merging cellular...
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The third-generation partnership project (3GPP) and 3GPP2 have standardized the IP multimedia subsystem (IMS) to provide ubiquitous and access network-independent IP-based services for next-generation networks via merging cellular networks and the Internet. The application layer Session Initiation Protocol (SIP), standardized by 3GPP and 3GPP2 for IMS, is responsible for IMS session establishment, management, and transformation. The IEEE 802.16 worldwide interoperability for microwave access (WiMax) promises to provide high data rate broadband wireless access services. In this paper, we propose two novel interworking architectures to integrate WiMax and third-generation (3G) networks. Moreover, we analyze the SIP-based IMS registration and session setup signaling delay for 3G and WiMax networks with specific reference to their interworking architectures. Finally, we explore the effects of different WiMax-3G interworking architectures on the IMS registration and session setup signaling delay.
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The IP multimedia subsystem (IMS) is able to deliver the multimedia messages through different types of networks, and alleviate the message losing in the single or fixed line network. With IMS supported, many applications can be i...
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The IP multimedia subsystem (IMS) is able to deliver the multimedia messages through different types of networks, and alleviate the message losing in the single or fixed line network. With IMS supported, many applications can be integrated in the seamless networking environment, so that users can access the network applications anytime and at anywhere. In this paper, we will introduce an on-line monitoring system with IMS platform for integrated networks. The proposal is able to associate with many value-added services, and users can access the services in the easy and convenience way. By the comparisons to other systems, our proposal not only is easily to use and deploy, but also provides most functions.
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The services of next generation networks are envisioned to be potentially capable of seamless mobility in spite of the heterogeneity in underlying access technologies. It is undoubted that to accomplish seamless services across he...
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The services of next generation networks are envisioned to be potentially capable of seamless mobility in spite of the heterogeneity in underlying access technologies. It is undoubted that to accomplish seamless services across heterogeneous networking environments gets harder in case of simultaneous mobility. In this article, we propose a mobile-initiated network-executed (MINE) session initial protocol (SIP)-based handover mechanism to facilitate simultaneous mobility in IP multimedia subsystem over heterogeneous accesses. The novelty of the proposed approach is that no changes are required to the existing network infrastructure since handover decision is fully made by the mobile host (MH) and handover execution is performed by a new-added application server called mobility server (MS). When the MH decides to initiate a handover and obtains a new IP address, it will send a SIP Publish message to trigger the MS to carry out the handover execution. With the network-executed design of the MINE, the MS can perform third-party registration for security re-association and third-party call control for session re-establishment in parallel. Moreover, the Master-Slave Determination procedures derived from H.245 are used in the MS to handle fairly the racing conditions resulting from simultaneous mobility such that redundant message flows are eliminated. Mathematical analyses present that the MINE can shorten the handover latency and reduce power consumption, as observed from a comparison with the integrated solution of an optimized macro-mobility mechanism and a receiver-side simultaneous mobility approach.
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Next Generation Networks (NGN) provide multimedia services to a large set of users by maintaining concurrent sessions for multimedia services using IP multimedia sub-system (IMS). SIP protocol are used for building, keeping and de...
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Next Generation Networks (NGN) provide multimedia services to a large set of users by maintaining concurrent sessions for multimedia services using IP multimedia sub-system (IMS). SIP protocol are used for building, keeping and detaching session with clients. The main problem is that intruders can launch SIP flooding attacks that cause a bottleneck at IMS entities. In this paper, we have presented a Dual Server based Intrusion Detection and Prevention System (DS-IDPS) to guard against INVITE flooding attack. We have proposed two-level security for VoLTE environment by involving two servers titled helper and main servers to handle spoofing and attack detection respectively. We have defined three thresholds at main server by utilizing CUSUM algorithm to generate alarms by detecting intrusion. By attaching DS-IDPS at the middle of client and server, our system filters every request. We have developed a test bed using OpenlMS to develop IMS entities and launch attacks by malicious nodes and detect the intrusion in the system. It reduces CPU load and memory stack from P-CSCF. Results prove that DS-IDPS produces lesser false alarms and detect more number of malicious or bogus requests. Our proposed approach dominates as compared to preliminaries in terms of memory utilization, response time, malicious requests recognition ratios and CPU load consumption.
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Nowadays, users of the internet are becoming increasingly popular, because of this rising load packets of network and delay requests. In this paper, we offer a method to improve allocation resource in the IMS servers. Implementati...
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Nowadays, users of the internet are becoming increasingly popular, because of this rising load packets of network and delay requests. In this paper, we offer a method to improve allocation resource in the IMS servers. Implementation of technology for balancing of loading in practice allows to optimize the decision of distribution tasks of signal and information flows on telecommunication networks. In case of uniform loading of the IMS servers and routers of a backbone network (devices of the network), the average time of a time delay of signal and information packets is minimum. Uniformity of loading of network devices is reached due to the uniform distribution of a flow of packets. The criterion of efficiency of methods of distribution of flows is the average square deviation (a balanced index) of congestion of network devices.
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摘要 :
Nowadays, users of the internet are becoming increasingly popular, because of this rising load packets of network and delay requests. In this paper, we offer a method to improve allocation resource in the IMS servers. Implementati...
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Nowadays, users of the internet are becoming increasingly popular, because of this rising load packets of network and delay requests. In this paper, we offer a method to improve allocation resource in the IMS servers. Implementation of technology for balancing of loading in practice allows to optimize the decision of distribution tasks of signal and information flows on telecommunication networks. In case of uniform loading of the IMS servers and routers of a backbone network (devices of the network), the average time of a time delay of signal and information packets is minimum. Uniformity of loading of network devices is reached due to the uniform distribution of a flow of packets. The criterion of efficiency of methods of distribution of flows is the average square deviation (a balanced index) of congestion of network devices.
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In Next Generation Network (NGN), IP Multimedia Subsystem (IMS) plays an important role to offer IP-based multimedia services. Based on Chunghwa Telecom's NGN/IMS, we develop linear-type data transmission applications such as Bull...
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In Next Generation Network (NGN), IP Multimedia Subsystem (IMS) plays an important role to offer IP-based multimedia services. Based on Chunghwa Telecom's NGN/IMS, we develop linear-type data transmission applications such as Bulletin Board System (BBS) or forum-based websites to deliver new articles to the mobile users. We propose the push-N method that pushes every N articles from the BBS server to the user. When the user actually connects to the BBS, the not-yet-pushed messages are pulled by the user. Our study indicates that by selecting appropriate N values, push-N can balance against the push and the pull operations, and therefore improves the user access experience without wasting too much network resources.
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