The Infona portal uses cookies, i.e. strings of text saved by a browser on the user's device. The portal can access those files and use them to remember the user's data, such as their chosen settings (screen view, interface language, etc.), or their login data. By using the Infona portal the user accepts automatic saving and using this information for portal operation purposes. More information on the subject can be found in the Privacy Policy and Terms of Service. By closing this window the user confirms that they have read the information on cookie usage, and they accept the privacy policy and the way cookies are used by the portal. You can change the cookie settings in your browser.
Since the first cellular networks were trialled in the 1970s, we have witnessed an incredible wireless revolution. From 1G to 4G, the massive traffic growth has been managed by a combination of wider bandwidths, refined radio interfaces, and network densification, namely increasing the number of antennas per site. Due its cost-efficiency, the latter has contributed the most. Massive MIMO (multiple-input...
In this paper, we analyze the benefits of including downlink pilots in a cell- free massive MIMO system. We derive an approximate per-user achievable downlink rate for conjugate beamforming processing, which takes into account both uplink and downlink channel estimation errors, and power control. A performance comparison is carried out, in terms of per-user net throughput, considering cell-free massive...
The standardization of 5G radio interface has started in 3GPP since April 2016. For the design of retransmission schemes, some requirements such as flexible timing, low overhead, and fast feedback have already been identified. Considering these design requirements, the retransmission mechanisms for single-hop and multi-hop 5G scenarios are presented in this paper. A novel protocol for the HARQ/ARQ...
In this paper, we revisit the radio network energy performance evaluation methodology, commonly known as E3F, that was developed in the European EARTH project during 2010–2011. We propose updates to the large-scale deployment and long-term traffic models in order to reflect the situation in a 5G time frame, and also an improvement in the sense that the baseline network is dimensioned to exactly meet...
In this paper we consider a time-division duplex cell-free massive multiple-input multiple-output (MIMO) system where many distributed access points (APs) simultaneously serve many users. A normalized conjugate beamforming scheme, which satisfies short-term average power constraints at the APs, is proposed and analyzed taking into account the effect of imperfect channel information. We derive an approximate...
In this paper, we evaluate the technology potential of a new 5G radio access technology (RAT), here denoted 5G-NX, in terms of energy performance at the country level, in order to show what can be expected in the future when networks are being modernized and new technology is rolled out. To this end, per deployment area we calculate the daily energy consumption via system level simulations considering...
Field trial measurements of small cell sleep mode with three different wake-up solutions are presented in this paper. A small heterogeneous LTE test network consisting of one macro base station and four small cells was deployed in Bundang, South Korea. Two UEs, one stationary and one moving, were used in the field trial. The studied solutions were (1) uplink interference based stand-alone small cell...
In this paper we examine the energy and user performance that can be achieved by combining antenna muting and dynamic three-sector to psi- omni site reconfiguration. A detailed algorithm is proposed for how to change on a sub-second timescale between a MIMO capable sector covering mode optimized for capacity, to a single transmit antenna psi-omni covering mode optimized for low energy consumption...
This paper presents the energy performance of a new radio access technology (RAT) component in 5G, here denoted as 5G-NX. The 5G-NX RAT encompasses massive beamforming and an ultra-lean design as two of its key technology components. The user throughput, resource utilization of the cells and daily average area power consumption are evaluated by means of system level simulations in an Asian city scenario,...
This paper evaluates the technology potential of using massive MIMO beamforming as a tool to enhance energy performance of radio networks. The geometry, user bit rate, required inter site distance, area power, discontinuous transmission ratio, and relative power consumption during transmission is evaluated by means of system level simulations and the results are compared with a traditional three-sectorized...
This paper presents a clean slate radio network solution, that has been designed with the aim to maximize energy performance. In traditional radio network designs, the energy cost for providing coverage (idle mode functionality) is totally dominating the network energy consumption. Here, a logical separation between idle mode functions and user plane data transmission and reception will be assumed...
Dynamic base station downlink discontinuous transmission (DTX) operations have been proposed and under discussion in the standardization body as a candidate to reduce interference in the LTE network to support rapidly increasing demand for mobile broadband services and traffic volumes [1]. In this paper, we analyze the energy efficiency improvement of the dynamic base station DTX operations from three...
Modern radio base stations (RBSs) typically consist of components such as radio units (RUs) and digital units (DUs) that are capable of supporting multiple radio access technologies (RATs) at the same time. This enables several different possible configurations of a multi-RAT site and in this paper we assess the energy performance of some promising configurations. We start by evaluating an LTE-only...
In this paper we examine the potential impact on total network energy consumption and CO2 emissions when LTE is introduced into an existing cellular network. We note that by replacing existing 2G or 3G hardware with modern equipment the energy consumption per node can be reduced by approximately 50% already today. Furthermore, based on power models from the EARTH project, we predict that this potential...
An attractive approach to meet increasing traffic demands is to densify existing cellular networks with low power nodes. This creates a heterogeneous network. In this paper we analyse the impact of such a densification on the network energy consumption and the possibilities it offers to enhance the network energy efficiency. In a heterogeneous network, the user performance can be significantly improved...
Energy consumption in mobile networks, e.g. 3G networks, may be a substantial part of an operator's expenses. A large part of the total energy of the network is consumed by the radio access network. Today operators are saving energy by turning off carriers or cells during periods with low traffic by manually configuring on-off periods. At the same time, operators are seeking to increase cost efficiency...
Link level performance results for physical antenna port muting in LTE are presented. In this paper we examine the block error rate performance of the LTE downlink control channels (PBCH, PCFICH, PDCCH, and the PHICH) for different antenna muting configurations. Also the throughput performance of the LTE downlink data channel (PDSCH) is studied for 2Tx and 4Tx transmit diversity formats. The results...
The concept of antenna muting for reducing energy consumption in LTE is presented and system level evaluation results are provided. The results indicate that antenna muting can reduce the energy consumption with up to around 50% in a low load scenario without significantly affecting the user throughput. Results for 4TX, 2TX, and 1TX cell configurations are presented. The system level simulator used...
Energy consumption in mobile networks, e.g. 3G networks, may be a substantial part of an operator''s expenses. A large part of the total energy of the network is consumed by the radio access network. One promising way to reduce the energy consumption of the radio network is to deactivate radio units during periods with low load. Significant gains can be achieved using this approach since each radio...
This paper discusses how energy consumption can be significantly reduced in mobile networks by introducing discontinuous transmission (DTX) on the base station side. By introducing DTX on the downlink, or cell DTX, we show that it is possible to achieve significant energy reductions in an LTE network. Cell DTX is most efficient when the traffic load is low in a cell but even when realistic traffic...
Set the date range to filter the displayed results. You can set a starting date, ending date or both. You can enter the dates manually or choose them from the calendar.