Electrical - Electronic Engineering / Elektrik - Elektronik Mühendisliği

Permanent URI for this collectionhttps://hdl.handle.net/11147/11

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  • Article
    Citation - WoS: 28
    Citation - Scopus: 28
    Multi-Helper Noma for Cooperative Mobile Edge Computing
    (Institute of Electrical and Electronics Engineers, 2022) Yılmaz, Saadet Simay; Özbek, Berna
    The next-generation wireless networks are expected to support a number of computation-intensive and delay-sensitive applications such as virtual reality (VR), autonomous driving, telesurgery and unmanned aerial vehicles (UAVs). Since many devices are computation and power limited, mobile edge computing (MEC) has been deemed as a promising way to enhance computation service. In this paper, we propose a novel cooperative MEC that exploits the combination of non-orthogonal multiple access (NOMA) and multiple helpers. In the proposed system featuring a user, multiple helpers and a base station (BS), the user can simultaneously offload its computation-intensive tasks to the helpers using NOMA when there is no strong direct transmission link between the user and the BS. Then, the helpers can compute and offload these tasks through NOMA. Thus, in the proposed scheme, the computation and offloading modes at the helpers are determined with respect to the optimized task offloading decision factor. The simulation results show that the proposed NOMA-based cooperative MEC significantly increases the total offloading data under the latency constraints compared to the benchmark schemes featuring one helper with strong direct transmission link. IEEE
  • Conference Object
    Citation - WoS: 2
    Citation - Scopus: 2
    Gezgin Rölelerin Dfbçe Tabanlı Hücresel Ağ Performansına Etkisi
    (Institute of Electrical and Electronics Engineers Inc., 2014) Baştürk, İlhan; Özbek, Berna
    OFDMA-based mobile relay enhanced cellular networks which have lower infrastructure cost and larger coverage areas are important technologies for the next generation communication systems since they allow to communicate at higher data rates. However, it is required to develop efficient radio resource management algorithms in order to reveal these advantages. Thus, in this study, relay selection and resource allocation algorithms are proposed for the mobile relay enhanced cellular networks. It is revealed that the number of satisfied users and the data rate of the cell-edge users that are far from the base station and have lower channel gains are increased by using mobile relays with the proposed algorithms.
  • Article
    User-Relay Assisted Cellular Networks With Multiple Antennas
    (Taylor & Francis, 2019) Baştürk, İlhan; Özbek, Berna
    User-relay assisted OFDMA-based cellular networks have gained great importance recently since these networks are indicated as one of the powerful technologies that will contribute the 5G standard. These networks can be used with novel three-phase frame structure unlike classical two-phase frame structure and can be enhanced with multiple antennas to utilise the advantages of them. The main advantage of the three-phase frame structure is taking care of the limitations of the current transceiver design in practical systems and not allowing users to be relay and user simultaneously. Diversity and capacity gains are also the advantages of extending the network with multiple antennas. In this paper, we will use the novel three-phase frame structure for downlink MISO-OFDMA cellular networks and develop resource management algorithms as relay selection and resource allocation to observe the benefits of this system.
  • Conference Object
    Citation - WoS: 2
    Citation - Scopus: 19
    New Concepts for Traffic, Resource and Mobility Management in Software-Defined Mobile Networks
    (Institute of Electrical and Electronics Engineers Inc., 2016) Ahmad, Ijaz; Liyanage, Madhusanka; Namal, Suneth; Ylianttila, Mika; Gurtov, Andrei; Faigl, Zoltan; Bokor, Laszlo; Perez, Oscar Lopez; Itzazelaia, Mikel Uriarte; Eckert, Marcus; Bauschert, Thomas; Saygun, Ece; Akyıldız, Hasan Anıl; Özbek, Berna; Ulaş, Aydın
    The evolution of mobile telecommunication networks is accompanied by new demands for the performance, portability, elasticity, and energy efficiency of network functions. Network Function Virtualization (NFV), Software Defined Networking (SDN), and cloud service technologies are claimed to be able to provide most of the capabilities. However, great leap forward will only be achieved if resource, traffic, and mobility management methods of mobile network services can efficiently utilize these technologies. This paper conceptualizes the future requirements of mobile networks and proposes new concepts and solutions in the form of Software-Defined Mobile Networks (SDMN) leveraging SDN, NFV and cloud technologies. We evaluate the proposed solutions through testbed implementations and simulations. The results reveal that our proposed SDMN enhancements supports heterogeneity in wireless networks with performance improvements through programmable interfaces and centralized control.