Patrick Agyapong

Design considerations for a 5G network architecture

This article presents an architecture vision to address the challenges placed on 5G mobile networks. A two-layer architecture is proposed, consisting of a radio network and a network cloud, integrating various enablers such as small cells, massive MIMO, control/user plane split, NFV, and SDN. Three main concepts are integrated: ultra-dense small cell deployments on licensed and unlicensed spectrum, under control/user plane split architecture, to address capacity and data rate challenges; NFV and SDN to provide flexible network deployment and operation; and intelligent use of network data to facilitate optimal use of network resources for QoE provisioning and planning. An initial proof of concept evaluation is presented to demonstrate the potential of the proposal. Finally, other issues that must be addressed to realize a complete 5G architecture vision are discussed.

Database-aided energy savings in next generation dual connectivity heterogeneous networks

This paper studies potential energy savings that can be realized in dual connectivity heterogeneous networks (HetNets) with densely deployed small cells. Using the Phantom Cell Concept (PCC) as a reference architecture, a novel database-aided mechanism is introduced to provide macro cell-controlled sleep mode functionality to small cells. System level simulations show that a system with this capability can yield energy savings of up to 40% and throughput gains of about 25% in dense deployment scenarios compared to a system where no energy savings scheme is implemented.

Energy savings in heterogeneous networks with clustered small cell deployments

Ultra dense small cell deployments will play a critical role in addressing future capacity requirements in dense urban outdoor and indoor environments such as train stations and shopping malls. Effective interference and energy management schemes will be needed to make such deployments technically and economically viable. In this paper, we demonstrate the benefits of a database-aided energy savings scheme for clustered small cell deployments. System-level simulations demonstrate that the proposed scheme can yield energy savings of up to 30% even when the network is heavily utilized, and offer throughput gains of up to 25% in case few users are present in the network, with respect to a conventional small cell deployment without the energy savings feature.

5G service requirements and operational use cases: Analysis and METIS II vision

One of the objectives of METIS-II project is to facilitate discussion on scenarios, use cases, KPIs and requirements for 5G, building upon the comprehensive work conducted in the METIS-I project and taking the work of other European projects as well as other bodies such as ITU-R, NGMN, etc. into account. This paper analyses the landscape of 5G use cases and presents METIS-II 5G use cases that cover the main 5G services, have stringent requirements and whose technical solutions are expected to serve other similar use cases as well. It also links these use cases to the business cases defined by 5G PPP so that requirements of vertical industries can be taken into account when designing the 5G Radio Access Network (RAN).

Impact of Varying Traffic Profile on Phantom Cell Concept Energy Savings Schemes

Sleep mode techniques can provide energy savings in Phantom Cell Concept (PCC) systems. However, the impact of the traffic profile on the performance of these energy savings schemes is not well understood. In this paper, we evaluate the influence of the size of transmitted files on the network performance. Contrary to previous findings, we show that for smaller file sizes the connection latencies associated with different energy savings schemes do have a non-negligible impact on system performance. However, as the file size increases, the influence of the connection delays associated with different schemes becomes negligible. The particular file size inflection point depends on the ratio of bandwidth resources on the small cell and the macro cell.

File size-based small cell connection in Phantom Cell Concept energy savings schemes

Energy savings schemes, in which unused small cells are put into a low power sleep mode, are an efficient way to reduce the energy consumption in Phantom Cell Concept (PCC) systems. Existing energy savings schemes, in which a user equipment (UE) is connected to a small cell whenever it needs to receive data, yield a significant amount of energy savings. To further reduce the energy consumption of PCC systems, we introduce in this paper two methods making a user connect or not to a small cell, based on the size of arriving files. Performance results show that using the size of the file to be received as an additional cell selection parameter can yield a further 5% energy savings in certain conditions, at minimal cost to user quality of service (QoS), with respect to the amount of energy savings obtained with existing schemes.