Applications supporting various multimedia data in wireless multimedia sensor networks (WMSNs) have specific QoS requirements on bandwidth, delay, and/or packet loss. Perception of applications' QoS requirements and detection of link states are indispensable for the design of QoS-aware routing mechanism. Software defined networking (SDN) is suitable for the purpose since it provides visibility of network resources and programmable interfaces. OpenFlow is the most recognized realization of SDN. We propose a QoS-aware routing mechanism for OpenFlow-enabled WMSNs. The mechanism consists of a framework and routing algorithms on SDN controller. The framework includes two functions: detection of link states among OpenFlow-enabled nodes and determination of flow's QoS requirements. The routing algorithms are achieved in two steps. First, the SDN controller seeks the feasible paths that satisfy QoS requirements of a flow. If there is no path which satisfies the required QoS, the path will be decided by the proposed algorithms depending on flow types: delay-sensitive, bandwidth-sensitive, and best-effort traffic. We conducted experiments on a SDN testbed to evaluate our mechanism and compared the results with conventional routing protocols. The results show that proposed routing mechanism increases the throughput by 43% for video data and reduces the delay by more than 30% for audio data.

In mobile SCTP, a mobile terminal has two or more network interfaces and vertical handover occurs when it moves from one network to another. The delay due to the handover process and the slow-start phase of SCTP's congestion control after handover cause substantial performance degradation. If the mobile node goes back and forth frequently, excessive handovers occur and data transmission quality deteriorates. In order to provide the required level of QoS for on-going application, the frequency of handovers should be kept minimized. In this paper, we propose a transport layer handover mechanism using the mobile SCTP. We take the QoS requirements of application as the major criterion in deciding path switching. In our mechanism, the mobile node in overlapping area does not perform handover if the current network metrics satisfy the QoS requirements of on-going application. Both analytic evaluation and simulation results show that the proposed mechanism significantly improves the throughput by suppressing unnecessary handovers. Our research results can also be applied to distributed mobile sensor networks.

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In the environment of data explosion, how to make an effective and accurate personalized point of interest (POI) recommendation in location-based social networks (LBSNs) is a challenging and meaningful task. Fortunately, there is a lot of information that we can use. We can make recommendations by mining the rich information hidden in user check-in records. In this paper, we propose a recommend system named GFP-LORE. Specifically, we have designed a framework, which integrates various influencing factors. First, we modeled friend sign-in frequencies and POI popularity as a power-law distribution and the experiment proved that it is effective. Then, we got the influence of geographic information by modeling it according to the longitude and latitude of the user's check-in location. After that, we sorted the historical check-in records of all users according to time and then mine an overall pattern of location transfer-order pattern. Then, we combine it with each user's own unique location transfer record to get the possibility of the user going to the next POI. Finally, we synthesize the above four influence factors into a unified correlation probability rating and recommend a new location by this probability rating. We tested our system on the open real check-in data set, and the results of our simulation experiments show that the recommendation effect of our system is better than those algorithms used in the contrast test.

SUMMARYInformation Centric Networking (ICN) is a promising architecture as an alternative paradigm to traditional IP networking. The innovative concepts, such as named data, name-based routing, and innetwork caching bring lots of benefits to Wireless Sensor Networks (WSNs). Simple and robust communication model of ICN, based on interest/data messages exchange, is appealing to be deployed in WSNs. However, ICN architectures are designed for power supplied network devices rather than resource-constrained sensor nodes. Introducing ICN-liked architecture to WSNs needs to rethink the naming scheme and forwarding strategy to meet the requirements of energy efficiency and failure recovery. This paper presents a light weight data centric routing mechanism (GRMR) for interest dissemination and data delivery in location-aware WSNs. A simple naming scheme gives assistance for routing decision by individual nodes. Greedy routing engaging with regional multicast mechanism provides an efficient data centric routing approach. The performance is analytically evaluated and simulated in NS-2. The results indicate that GRMR achieves significant energy efficiency under investigated scenarios.

Abstract. With the proliferation of mobile device and applications, a large number of mobility management solutions have been proposed to support mobility in IP networks. Mobile IP and its derivatives are basically network layer solutions for terminal mobility problems. However, there are several shortages in those solutions, such as large overhead, high latency, lack of scalability and weak security. Software Defined Networking (SDN) provides a flexible centralized approach to handle mobility in IP networks. In this paper, we propose a network based secure mobility management architecture. SDN controller manages the mobility with full authority and controls OpenFlow Switches to forward packets for mobile nodes in optimal path. The implementation and test results show a better delay and throughput performance during the handover process. IntroductionWith the growing number of mobile devices (e.g., smart phones, tablets, and laptop computers), the demand for mobility management is becoming a primary requirement in current mobile infrastructure. Today's cloud-enabled, everything-as-a-service (XaaS) [1] network environments expect to provide simple and secure mobile access to all the data and applications for users, regardless of their physical location. Service providers want to make it easy to locate users and provision their services ubiquitously. Currently, IP mobility solutions (Mobile IP (MIP) [2] with its derivatives, variations, and auxiliary [3][4][5][6]) are insufficient in terms of scalability and resource utilization to large scale mobile networks. It is urgent to excogitate more flexible and easier methods to provide world-wide mobility support. Software Defined Networking (SDN) [7] is an emerging network architecture approach. The separation of control plane with data plane is its essential feature and the evolution comparing with traditional fixed IP networks. In SDN, the underlying network infrastructure is abstracted from applications while network structures, functions and status are logically centralized. OpenFlow [8] is the potential protocol for the communication between controllers and OpenFlow Switches (OFSs). OFSs are simply responsible for data forwarding based on their flow table which is configured by controller. SDN controllers expose and abstract various network functions and * Corresponding author.

Mobile Edge Computing (MEC) technology brings the unprecedented computing capacity to the edge of mobile network. It provides the cloud and end user swift high-quality services with seamless integration of mobile network and Internet. With powerful capability, virtualized network functions can be allocated to MEC. In this paper, we study QoS guaranteed multicasting routing with Network Function Virtualization (NFV) in MEC. Specifically, data should pass through a service function chain before reaching destinations along a multicast tree with minimal computational cost and meeting QoS requirements. Furthermore, to overcome the problems of traditional IP multicast and software-defined multicasting approaches, we propose an implementable multicast mechanism that delivers data along multicast tree but uses unicast sessions. We finally evaluate the performance of the proposed mechanism based on experimental simulations. The results show that our mechanism outperforms others reported in the literature.

Throughout the last decade, overlay multicast is a hot issue for media distribution services. High bandwidth consumption and multi-source multicasting in widely distributed networks is a critical issue for a wide range of applications including video conferencing, multi-party games, content distribution etc. A number of research projects have explored to use multicast as an efficient and scalable mechanism to deal with group oriented communications. However, there are still some limitations, such as long latency, duplicated packet transmission at certain points and lack of network equipment functionality support. With the appearance of Software Defined Networking, represented by OpenFlow devices, network control and management becomes possible to remote administrators. With the support of OpenFlow, it is possible to do some optimizations of existing media distribution mechanisms in overlay networks. In this paper, we proposed a novel method to improve the traditional overlay multicast relay networks with available limited number of OpenFlow devices, to cut down the bandwidth expenditures and perform a good control and management of media distribution services.