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BGP prefix hijacking is one of the top threats on the Internet. The traditional approaches are mainly to analyze the prefix changes of the control plane, or to use the active measurement detection method to obtain the reachability of the prefix to determine whether there is prefix hijacking. These approaches rely on extensive infrastructures, wide coverage of measurement points, and long-term continuous detection. In this paper, we propose a BGP prefix hijacking detection method based on multi-dimensional historical data analysis, which can avoid the high deployment cost and long detection delay of active measurement methods. We test the proposed method on 1487 prefix hijacking events identified by BGPStream, from which more than 99% (1475/1487) prefix hijacking events are detected. The results show that the proposed method can effectively and accurately detect prefix hijacking.

In order to meet the needs of real-time services in the low-orbit communication network, the paper draws on the related research of edge computing technology in the ground broadband network and applies it to the LEO satellite constellation communication network, sinking the processing power of the backend cloud center (CC) to the nodes close to the user terminals, thereby reducing the response delay of the task and the bandwidth consumption of the backhaul network in the LEO constellation networks. This paper proposes a sever selection strategy based on queuing theory and weighting method. For the computing offload requests submitted by frontend users, this strategy first regards the nearest accessing satellite edge computing node as the first choice to offload computing tasks; if it is not qualified, then synthetically consider various factors, such as the total energy consumption of the data transmission and calculation for the request, the load balancing among the computing nodes, and the response delay to the user, etc. These factors for candidate computing nodes are scored separately, and the all-around score is finally used to select the most suitable computation offloading node. Comprehensive simulation experiments show that, compared with another two approaches, the proposed strategy can ensure that user requests are well satisfied, and can reduce the average response delay in the range from 17% up to 34%.

The combination of edge computing and LEO satellite broadband network has the potential to provide ground users enhanced services with significantly lower latencies. This paper derives a offloading model and a user model of LEO satellite constellation networks and proposes a multi-level computation offloading scheme. This scheme designs a multilevel edge-projection pursuit (MLEPP) model and uses an optimization method to find the optimized projection direction in order to obtain the most suitable offloading choices. On the other hand, a discrete event-based Monte Carlo simulator is developed to evaluate the proposed computation offloading scheme. Comparative evaluation experiments have been conducted, and the results indicate that, in resource-restricted scenarios, using the derived multi-level offloading scheme can effectively and efficiently decrease the average request blocking probability, the average request corresponding delay, and keep the average request cost at a restricted level.

Network emulation is a vital testing and verification approach for networking protocols of all layers, as well as for application software during a network’s entire life-cycle from designing to maintenance phases. Network emulation method combines the merits of simulation and test-bed, and balances cost and accuracy. This paper introduces a promising cloud-based network emulati on platform, which leverages a set of novel virtualization and cloud related technologies to implement flexibility, agility and scalability in network emulation domain. Aiming at realizing high fidelity (HiFi) network emulation, External physical network nodes should be able to connect and communicate with the emulated nodes. This paper elaborates an innovative strategy to integrate outside physical nodes with virtual nodes inside of the emulation platform to implement virtual and physical nodes fused network emulation. Functional tests are carried out and indicate that the proposed strategy can effectively bridge the physical node to the virtual platform to achieve HiFi network emulation. Besides, performance evaluation also illustrates that the derived strategy can efficiently utilize the limited computation and networking resources of the platform so to achieve sufficient scalability and flexibility for the typical emulation scenarios.

Information Centric Networking (ICN) is a promising future networking architecture, and Named Data Networking (NDN) is considered to be its authoritative and representative scheme. In recent years, applying ICN/NDN concept in Mobile Ad-hoc Network (MANET), i.e. Name Data Mobile Ad-hoc Network (NDMANET), becomes a research hotspot. Compared with traditional IP protocol, NDN scheme is thought to be more robust and profitable to the node mobility and dynamically changed topologies in MANET. This paper focuses on NDMANET’s in-networking caching strategy, which provides a great flexibility and efficiency for data dissemination and is a vital feature of NDMANET. Firstly, the paper investigates and analyzes some existing caching strategies which are widely applied in the ICN/NDN domain. On that basis, a novel Content Popularity and Distance based Interval (CPDI) caching strategy is derived for NDMANET, with the purpose of improving its network performance. Comprehensive simulation experiments have been carried out and the results illustrate that the proposed CPDI caching strategy can introduce considerable improvements on the average cache hit ratio, the average number of cached data packets, and the average energy consumption with only slightly degrading the average download delay.

In the recent past, satellite TV faces fierce market competitions with cable TV, IPTV, and the increasingly prevalent Internet TV. It can be anticipated that, in order to successfully survive in the next decade, satellite TV operators will deliver a larger number of TV channels with diverse programs in enhanced video formats, such as ultra-HD and 3D, to bring viewers much richer video and audio experience. Consequently, a lot more bandwidth will be needed in satellite TV broadcast networks, in particular in the satellite-ground links. In this paper, we firstly propose a conceptual transmission model which is promising for the next generation satellite TV systems. Then, we derive an adaptive coding and modulation (ACM) based TV channel multicast scheme to reduce frequency bandwidth resource consumption. We have carried out comprehensive simulation experiments to illustrate that the proposed ACM-based multicast scheme can effectively and efficiently reduce the Ka-band bandwidth consumption in spot-beams more than 2/3, with only slightly degrading the CBP up to 2%.

Television industry lately started to provide viewers with ultra-HD (UHD) TV programs, which considerably increases the transmission bandwidth requirements, in particular in satellite TV broadcasting systems. This paper proposes a hybrid broadcast & multicast channel transmission scheme for the next generation satellite TV systems, which according to the simulation results can effectively decrease frequency bandwidth consumption while still providing users affordable QoE.

IPTV services in vehicular networks are currently attracting increasingly more attentions. One essential challenge is to efficiently utilize the limited radio resources in vehicular access networks. This paper assumes that scalable video coding (SVC) is used to encode TV channels. Since TV channels usually possess different popularities, the paper proposes a novel transmission scheme, which employs differentiated modulation and coding scheme (MCS) profiles for channels of different popularities. The principle is to use more robust MCS profiles for more popular channels while to adopt higher efficient MCS profiles for less popular channels. Comparative simulation experiments are conducted and show that the proposed scheme can effectively and efficiently improve the gross channel availability (GCA) up to 10% compared to the baseline method.

IPTV clients' sequential zapping behavior can introduce extra traffic load in underlying transmission networks, which may greatly degrade client Quality of Experience (QoE). It is therefore highly desirable to enhance IPTV channel availability (one of the most important QoE metrics) in IPTV systems with clients zapping channels sequentially. To this end, this paper proposes an Active Channel Changing Delay (ACCD) admission control method in combination with an n-layered (one base layer and n-1 enhancement layers) Scalable Video Coding (SVC) profile to alleviate the aforementioned impact caused by client sequential zapping. Comprehensive simulation experiments are carried out and show that the proposed ACCD method are capable of significantly improving channel availability and hence can enhance client QoE in bandwidth restricted IPTV delivery networks, with only slightly increasing the average service delay of channel enhancement layers.

Vehicular Networks represent one of the main topics in the communication systems area. Increased deployment of vehicular networks together with new possibilities for Internet Protocol Television (IPTV) services has spurred the interest in providing mobile IPTV via vehicular networks. Provisioning of IPTV services over vehicular networks can be expected to play a significant role in the next generation of TV systems. Users will choose IPTV based on the Quality of Experience (QoE). Among QoE measures, TV channel availability is one of the most significant. In this paper, we investigate the channel availability in IPTV services with different traffic intensity and a varying number of TV channels offered to find out the acceptable availability of TV channels or the Call Blocking Probability (CBP) in our study. Comprehensive experiments are carried out by means of our own simulation tool, i.e., a Monte Carlo simulator to conduct the evaluations for numerous scenarios taking into account realistic IPTV user behavior.

The current trend of network convergence has been best exemplified by the recent emergence of new services such as Broadband TV (BTV) offered by Telcos around the world. A very relevant research topic is to improve the quality of experience (QoE). This paper focuses on decreasing the user call blocking probability (CBP), which is one of the most important BTV QoE metrics. At first, we analyze a currently typical BTV network architecture. And then, a state-vector-based simulation model is proposed to evaluate the CBP (on a single link). After that, we present a class-based distribution model of channel watching probabilities, and based on this distribution model, we elaborate a general TV channel access control (TCAC) scheme in order to reduce the CBP. This scheme is flexible and can be applicable in many different scenarios. Finally, a case study is carried out, and it demonstrates the potential of this TCAC scheme to improve the BTV QoE by decreasing the CBP on a single link.