Device-to-Device (D2D) communication is a new technology that offer many advantages for the LTEadvanced network such us wireless peer-to-peer services and higher spectral efficiency. It is also considered as one of promising techniques for the 5G wireless communications system and used in so many different fields such as network traffic offloading, public safety, social services and applications such as gaming and military applications. The goal of this paper is to present advances on the current 3GPP LTE-advanced system related to Device-to-Device (D2D). In this paper, we provide an overview of the D2D types based on the communication spectrum of D2D transmission, namely Inband D2D communication and Outband D2D communication. Then we present the advantages and disadvantages of each D2D mode. Moreover, architecture and protocol enhancements for D2D communications under LTE-A network are described.

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With The rapid growth of mobile networks data and the emergence of the new services and applications, Mobile operators should provide a several solutions to cope with the challenges of the next 5G mobile networks and to reduce costs. For these reasons, SDN was proposed to be one of the key technology trends that will facilitate the required architectural agility needed in the next 5G mobile networks. Software Defined Networking (SDN) is the highly promising technology to provide innovation and enforce the main drivers in 5G mobile networks such as flexibility, suability, service-oriented management and to reduce costs by the softwarization of the 5G Core networks functions. Thus, there is an immediate need to study the fundamental architectural principles of SDN, and to analyze the integration and application scenarios of this architecture into the next 5G mobile networks. In this paper, we present a survey on the most relevant research works on SDN concepts and SDN integration in mobile networks. We propose a SDN-based architecture for 5G mobile network; we give an overview of SDN requirements and challenges for SDN integration in 5G, we address the benefits of IPv6 over SDN in 5G and finally we provide the benefits of SDN integration in 5G mobile networks.

Energy is the most valuable resource in wireless sensor networks; this resource is limited and much in demand during routing and communication between sensor nodes. Hierarchy structuring of the network into clusters allows reducing the energy consumption by using small distance transmissions within clusters in a multihop manner. In this article, we choose to use a hybrid routing protocol named Efficient Honeycomb Clustering Algorithm (EHCA), which is at the same time hierarchical and geographical protocol by using honeycomb clustering. This kind of clustering guarantees the balancing of the energy consumption through changing in each round the location of the cluster head, which is in a given vertex of the honeycomb cluster. The combination of geographical and hierarchical routing with the use of honeycomb clustering has proved its efficiency; the performances of our protocol outperform the existing protocols in terms of the number of nodes alive, the latency of data delivery, and the percentage of successful data delivery to the sinks. The simulations testify the superiority of our protocol against the existing geographical and hierarchical protocols.