Sami Hakola

Bio: Sami Hakola is an academic researcher from Nokia. The author has contributed to research in topics: Random access & Telecommunications link. The author has an hindex of 13, co-authored 32 publications receiving 1385 citations. Previous affiliations of Sami Hakola include Broadcom & Nokia Networks.

Resource allocation for d2d communication

Abstract: There is provided a mechanism for allocating communication resources of a cellular communication network to a D2D communication. After an eNB has configured a number of resource pools indicating a set of resources usable in the D2D communication, D2D clusters which share a same resource pool are enabled to obtain resources for their respective D2D communication. By detecting the current resource utilization state in the allocated resource pool by measurement on the UE side, it is decided whether suitable resources are available or not. An overload situation is signalled to the eNB if no suitable resource can be detected.

Device-To-Device (D2D) Communication in Cellular Network - Performance Analysis of Optimum and Practical Communication Mode Selection

Abstract: In a cellular network system one way to increase its capacity is to allow direct communication between closely located user devices when they are communicating with each other instead of conveying data from one device to the other via the radio and core network. The problem is then when the network shall assign direct communication mode and when not. In previous works the decision has been done individually per communicating device pair not taking into account other devices and the current state of the network. We derive means for getting optimal communication mode for all devices in the system in terms of system equations. The system equations capture information of the network such as link gains, noise levels, signal-to-interference-and-noise-ratios, etc., as well as communication mode selection for the devices. Using the derived equations performance bounds for the cellular system where D2D communication is an additional communication mode are illustrated via simulations. Further, practical communication mode selection algorithms are used to evaluate their system performance against the achievable bounds. Analysis show the usability of the system equations and the potential of having D2D operation integrated into a cellular system when there is enough local communication occurring.

The investigation of power control schemes for a device-to-device communication integrated into OFDMA cellular system

Abstract: Power control is one of the key functions which are able to co-ordinate the system interference. In this paper, several power control schemes are investigated for a hybrid LTE system, which combines the direct device-to-device (D2D) mode communication and the normal cellular mode communication. In the system study, the power control for the D2D mode communication is emphasized. In general, the utilization of local area transmission for D2D communications provides a better SINR than normal cellular communications. In this case, the proper power control for D2D communications can be a flexible way to improve (and balance) the overall system performance. Naturally, the low power transmission of D2D communications leads to many potential advantages, such as low interference level (to normal cellular users) and low power consumption. From the power control point of view, the low power transmission provides more freedom to tune the Tx power. However, power control is not an efficient solution to avoid the strong mutual (co-channel) interference between different types of UEs. In this case, the join consideration of mode selection, resource scheduling, link adaption and power control is needed.

Apparatus and method for mode selection for device-to-device communications

Abstract: In accordance with an example embodiment of the present invention, a method is disclosed that comprises measuring a first link quality of a first link based at least in part on a first power value; measuring a second link quality of a second link based at least in part on a second power value; and determining a suitable device-to-device (D2D) mode for a D2D connection based at least in part on the first link quality, the second link quality, and one or more D2D user equipment (UE) constraints.

Network controlled Device-to-Device (D2D) and cluster multicast concept for LTE and LTE-A networks

Abstract: In this paper we introduce a reliable multicast concept for Device-to-Device (D2D) communication integrated into cellular network. In addition to the introduction of the basic concept, initial simulation results are presented as well. Clustering closely located devices which have local communication needs is a feasible and efficient way of solving the increasing data traffic requirements in the future cellular network. Reliable D2D multicast concept introduced in this paper is designed to be scalable and efficient solution for local communication needs such as file transfer and even streaming services. Due to the network involvement in controlling the local D2D communication, sufficient quality of service can be guaranteed. In addition, due to the flexible mode switching between direct and cellular modes in the integrated operation the service continuity can be provided.

A Survey on Device-to-Device Communication in Cellular Networks

Abstract: Device-to-device (D2D) communications was initially proposed in cellular networks as a new paradigm for enhancing network performance. The emergence of new applications such as content distribution and location-aware advertisement introduced new user cases for D2D communications in cellular networks. The initial studies showed that D2D communications has advantages such as increased spectral efficiency and reduced communication delay. However, this communication mode introduces complications in terms of interference control overhead and protocols that are still open research problems. The feasibility of D2D communications in Long-Term Evolution Advanced is being studied by academia, industry, and standardization bodies. To date, there are more than 100 papers available on D2D communications in cellular networks, but there is no survey on this field. In this paper, we provide a taxonomy based on the D2D communicating spectrum and review the available literature extensively under the proposed taxonomy. Moreover, we provide new insights into the over-explored and under-explored areas that lead us to identify open research problems of D2D communications in cellular networks.

A Survey on Device-to-Device Communication in Cellular Networks

Abstract: Device-to-Device (D2D) communication was initially proposed in cellular networks as a new paradigm to enhance network performance. The emergence of new applications such as content distribution and location-aware advertisement introduced new use-cases for D2D communications in cellular networks. The initial studies showed that D2D communication has advantages such as increased spectral efficiency and reduced communication delay. However, this communication mode introduces complications in terms of interference control overhead and protocols that are still open research problems. The feasibility of D2D communications in LTE-A is being studied by academia, industry, and the standardization bodies. To date, there are more than 100 papers available on D2D communications in cellular networks and, there is no survey on this field. In this article, we provide a taxonomy based on the D2D communicating spectrum and review the available literature extensively under the proposed taxonomy. Moreover, we provide new insights to the over-explored and under-explored areas which lead us to identify open research problems of D2D communication in cellular networks.

Resource Sharing Optimization for Device-to-Device Communication Underlaying Cellular Networks

Abstract: We consider Device-to-Device (D2D) communication underlaying cellular networks to improve local services. The system aims to optimize the throughput over the shared resources while fulfilling prioritized cellular service constraints. Optimum resource allocation and power control between the cellular and D2D connections that share the same resources are analyzed for different resource sharing modes. Optimality is discussed under practical constraints such as minimum and maximum spectral efficiency restrictions, and maximum transmit power or energy limitation. It is found that in most of the considered cases, optimum power control and resource allocation for the considered resource sharing modes can either be solved in closed form or searched from a finite set. The performance of the D2D underlay system is evaluated in both a single-cell scenario, and a Manhattan grid environment with multiple WINNER II A1 office buildings. The results show that by proper resource management, D2D communication can effectively improve the total throughput without generating harmful interference to cellular networks.

Operator controlled device-to-device communications in LTE-advanced networks

Abstract: This article studies direct communications between user equipments in the LTE-advanced cellular networks. Different from traditional device-to-device communication technologies such as Bluetooth and WiFi-direct, the operator controls the communication process to provide better user experience and make profit accordingly. The related usage cases and business models are analyzed. Some technical considerations are discussed, and a resource allocation and data transmission procedure is provided.

Device-to-Device Communication in LTE-Advanced Networks: A Survey

Abstract: Among the LTE-A communication techniques, Device-to-Device (D2D) communication which is defined to directly route data traffic between spatially closely located mobile user equipments (UEs), holds great promise in improving energy efficiency, throughput, delay, as well as spectrum efficiency As a combination of ad-hoc and centralized communication mechanisms, D2D communication enables researchers to merge together the long-term development achievements in previously disjoint domains of ad-hoc networking and centralized networking To help researchers to have a systematic understanding of the emerging D2D communication, we provide in this paper a comprehensive survey of available D2D related research works ranging from technical papers to experimental prototypes to standard activities, and outline some open research problems which deserve further studies