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    Switching of routing algorithms in wireless networks for fire fighting
    (Springer, 2013)
    An, Chunlei
    ;
    Luo, Yunqi
    ;
    Timm-Giel, Andreas
    Fire fighters often work in dangerous and dynamic environments, which results in frequent change of network topologies and routing requirements. While the existing routing protocols are not able to cope with such a changeable environment, this paper proposes a self adaptive hybrid routing algorithm. This routing algorithm can switch between the proactive routing algorithm and reactive routing algorithm for each node pair automatically. An analytical model is created to describe the routing switch decision making algorithm. This model is based on a set of the cost functions. A numerical example shows the necessity of switching routing algorithms to reduce the overall control message overhead. © Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2013.
    Publicationtype: Conference Paper
      71
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    QoS impact of hierarchical routing in multi-channel sensor networks
    (Springer, 2013)
    Torres, Luis
    ;
    Killat, Ulrich
    Enabling integration of Wireless Sensor Networks (WSN) and smart objects with the Internet is an important milestone towards the so called Internet of Things. Providing these networks with QoS capabilities is crucial for emerging applications that have end-to-end requirements on the border wireless network domain. Impairments such as delays and losses are heavily influenced by the quality of the communication channels, the routing, the MAC protocol and the interactions of these influential factors. In this work we report on a hierarchical routing scheme for sensor networks with multi-channel radios aiming at improving QoS. The scheme decouples the aforementioned influences: The MAC-protocol is responsible for a scheduling in a set of nodes called a cluster. Neighboring clusters use different frequencies. The routing is done at the level of clusters. The (distributed) algorithms executed by the network nodes to support this architecture are evaluated against optimal solutions for clustering, frequency allocation and routing derived from Integer Linear Programming. © Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2013.
    Publicationtype: Conference Paper
      67
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    Prototype: OConS multi-path content delivery with NetInf
    (Springer, 2013)
    Udugama, Asanga
    ;
    Görg, Carmelita
    ;
    Timm-Giel, Andreas
    One of the primary activities of today's networks is the movement of content. This has made the point-to-point communication architecture of current networks unsuitable for today's needs. Information Centric Networking (ICN) changes this model with newer networking architectures such as the Network of Information (NetInf). The multipath capabilities that are much admired in current networks, have also been integrated into these architectures. But, these architectures do not define formal mechanisms to utilise these multiple paths to avail their benefits. The prototype presented in this work demonstrates the use of multi-path content delivery in NetInf based ICN networks through the Open Connectivity Services mechanisms and framework.
    Publicationtype: Conference Paper
      97
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    A re-optimization approach for virtual network embedding
    (Springer, 2013-09-02)
    Melo, Márcio
    ;
    Carapinha, Jorge
    ;
    Sargento, Susana
    ;
    Killat, Ulrich
    ;
    Timm-Giel, Andreas
    Network Virtualization is claimed to be a key component of the Future Internet by enabling the coexistence of heterogeneous (virtual) networks in the same physical infrastructure, providing the dynamic creation and support of different networks with different paradigms and mechanisms in the same physical network. A major challenge in the dynamic provision of virtual networks resides in the optimal embedding solution of virtual resources into physical ones. Since this problem is known to be NP-hard, previous research focused on designing heuristic-based algorithms; most of them do not consider either a simultaneous optimization of the node and the link mapping or the re-optimization of VNs, leading to non-optimal solutions. This paper proposes an extension of Virtual Network Embedding - Node-Link Formulation to support the re-optimization of existing VNs and to provide the optimal bound. It also presents an evaluation of the proposed approach when applied to a previous heuristic in the literature. Simulation experiments show significant improvements when using the VN re-optimization process: not only the bandwidth consumption have been reduced by 17.5%, but the same is true for the maximum utilization levels on the CPU and on the memory. © Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2013.
    Publicationtype: Conference Paper
      132
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    Uplink QoS aware multi-homing in integrated 3GPP and non-3GPP future networks
    (Springer, 2013)
    Toseef, Umar
    ;
    Zaki, Yasir
    ;
    Timm-Giel, Andreas
    ;
    Görg, Carmelita
    Future wireless networks will consist of a mixed heterogeneous 3GPP and non-3GPP access technologies. The 3rd Generation Partnership Project 3GPP has already facilitated the integration of non- 3GPP access by standardizing the System Architecture Evolution (SAE) where non-3GPP access technologies can co-exist with 3GPP access networks. In such heterogeneous networks though the seamless vertical handovers can be performed between the available access networks, the question still remains whether the Quality of Service (QoS) demands of user applications can be satisfied from QoS unaware non-3GPP access technologies? Within the context of the Open Connectivity Services (OConS) of the SAIL European project[1], this work investigates the effects of the integration of two network types on user Quality of Experience (QoE) in the uplink direction. In order to realize QoS guaranteed service from non-3GPP access technologies, this paper proposes two novel resource estimation and management algorithms. With the help of simulation it is shown that integration of non-3GPP technologies in the existing 4G networks extends the network capacity without compromising the user QoE when the proposed schemes are deployed.© Institute for Computer Sciences, Social Informatics and Telecommunications Engineering 2013.
    Publicationtype: Conference Paper
      202