Mårten Ericson

Total Network Base Station Energy Cost vs. Deployment

Energy efficient radio networks, i.e. radio base stations and transport network mainly, are something that becomes more and more important with the increase of installed base stations globally. This study evaluates the total base station energy consumption per area (

Mixed Traffic HSDPA scheduling - Impact on VoIP Capacity

W/km^2

Capacity study for fixed multi beam antenna systems in a mixed service WCDMA system

) for different cell sizes (deployments). This is done by theoretical calculations assuming a certain minimum received power at the cell edge regardless of cell size and channel model. This study shows that with just a minimal fixed power consumption overhead factor for each cell (e.g. 0.1 W per cell), it is never optimal to build a cellular network as dense as possible from an energy consumption per area point of view. Only when there is no fixed overhead at all, the optimal cell size from an energy per area perspective, is as small as possible. With a rather low fixed overhead (1-5 W), the optimal inter-site-distance is around 300-700 m. With the current (high) fixed power consumption overhead, as large inter-site-distances as possible are the most energy efficient.

Assessment of Alternatives for Reducing Energy Consumption in Multi-RAT Scenarios

IMS multimedia telephony (MMTel) for cellular systems is currently being standardized in 3GPP. MMTel comprises a number of media components such as voice over IP (VoIP), real-time video, text messaging and file sharing. In this paper down-link scheduling performance of MMTel services for various scheduling algorithms is investigated in an HSDPA system. The studied service mixes include VoIP and file download (FTP), as well as VoIP and real-time video. The investigation of the schedulers is done over a wide range of traffic mix ratios, in order to give a full understanding of the performance. This paper shows that it is beneficial to have separate schedulers for each media flow. For an MMTel scenario with VoIP and file downloading, the best performance is achieved when using a delay scheduler for VoIP and a proportional fair (PF) scheduler for FTP. An extra priority weight for VoIP over FTP (or v.v.) makes it possible to control the wanted total service mix. With simultaneous VoIP and real-time video the best performance is achieved when both services utilize a delay scheduler, this since the VoIP and video flows shall be synchronized. However, the scheduler for the video flow requires different parameter settings, compared to the VoIP flow, in order to give the best performance.

Effects of simultaneous circuit and packet switched voice traffic on total capacity.

Antenna arrays at the base stations allow capacity enhancement in cellular WCDMA networks. In this contribution we compare the relative downlink capacity between a system employing standard three sector site configurations with a system employing four fixed beam antenna systems. Since different packet services are expected to contribute largely to the traffic demand within a few years after initial deployment, this comparison is made in a mixed traffic environment. By realistic computer simulations it is found that a substantial gain can be expected by the introduction of adaptive (smart) antenna base stations. In this contribution a fixed multi beam system is considered, which is a fairly low complex adaptive antenna implementation. The simulations show that generally, a threefold capacity increase can be gained by employing a 4 beam antenna system. For some scenarios even higher gains can be achieved.

WCDMA system level performance with fast fading and non-ideal power control

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 network and conclude that with traffic according to predictions for 2015 the average cell will be idle 95% of the time and the additional energy consumption due to the user plane traffic is only 1.4%. We also show that even a significant future traffic increase will only have a minor impact on the energy consumption. We further show in this paper that a multi-RAT RBS where the RATs share the digital unit (PA) have the potential to reduce the site energy consumption with 40% compared to a multi-RAT RBS with separate PAs for each RAT. For operators with multiple RATs on the same site but using separate PAs per RAT, it is still possible to reduce energy consumption by utilizing load balancing between the RATs. This study shows that a potential energy reduction in the order of 30% is possible by utilizing load balancing between HS and LTE.

Agile resource management for 5G: A METIS-II perspective

Introducing packet switched (PS) voice in cellular systems is often discussed in terms of circuit switched (CS) voice replacement. In this study, we investigate the differences in downlink resource consumption or capacity in a WCDMA system with both CS and PS voice traffic on the same 5 MHz carrier. The PS traffic is gradually increased, representing a migration from CS to a PS only scenario. The study comprises both theoretical calculations and system simulations of downlink voice traffic. The results show that gradually introducing PS voice traffic on the same carrier as CS speech gives equally good or better voice capacity without compromising the QoS requirements. Further on, introducing PS voice on the same carrier can be done in a very flexible way. The CS admission control thresholds can control the power usage for CS, and PS voice can thereafter use the remaining base station power. This means that the CS admission control can decide the ratio of CS and PS voice users, and increase the PS ratio gradually as the PS voice traffic becomes more common

Downlink capacity comparison between different smart antenna concepts in a mixed service W-CDMA system

This paper shows the need to include detailed link level characteristics in a system performance analysis and how this is implemented in a system simulator. It is a well-known fact that CDMA systems need accurate power control to achieve good performance. Detailed models of link level characteristics are needed in order to achieve reliable system level performance estimates of the power control algorithms. By including characteristic link level parameters such as FER, C/I and BER, together with multipath fading and a complete implementation of the closed and outer loop power control algorithms, we have created an environment for realistic simulations of the system algorithms. This enables us to study the effects on the system performance of e.g. delay, measurement errors, velocities of mobiles, multipath fading, and our power control algorithms in a dynamic cellular environment. The driving force behind our simulator implementation is to continuously improve the performance of the system algorithms and thus, in the end, to increase the capacity. The results show that a system simulator which includes detailed link level characteristics is a useful tool when studying the effects of the non-ideal power control.

The effect of F-DPCH on VoIP over HSDPA Capacity

An explosive growth in the demand for higher data rates and capacity along with diverse requirements set by massive and ultra-reliable machine-type communications are the main drivers behind the development on new access technologies as part of the fifth generation (5G) networks. Currently, different air interface (AIF) and/or AIF variants, optimized based on the frequency band of operation and use case, are envisioned for such a network. Developing an agile resource management framework for 5G networks is one of the main goals of the METIS-II project. The METIS-II project builds strongly upon the EU flagship project METIS, which has laid the foundation of 5G. This framework will take into account the multi-link and multi-layer constraints currently envisioned for 5G. In this paper, we provide our first insights into agile resource management and the associated synchronous control functions. We will discuss the essential building blocks in terms of technology enablers and their mapping to 5G services and deployments. The introduced agile resource management framework for 5G is expected to enable enhanced interference management, dynamic traffic steering, fast radio access network (RAN) moderation, efficient context management, and optimized integration with legacy networks.

Evaluation and Analysis of SIP and VOIP Performance with Presence Traffic over HSPA

The capacity of W-CDMA systems in which base stations are equipped with adaptive antennas (AA) is investigated in mixed service scenarios. The simulations show that generally, a threefold downlink (DL) capacity increase can be gained by employing a fixed or steered beam antenna system. For some scenarios, DL capacity gains of 4 to 6 times can be achieved. Further, a DL capacity comparison between the steered beam concept and the fixed (multi) beam AA concept is presented.