Mikko Säily

Improved mobility performance in LTE co-channel hetnets through speed differentiated enhancements

This paper analyzes the mobility performance of LTE (Long Term Evolution) co-channel heterogeneous networks (HetNet) with macro and pico cells. Improved methods for differentiating offload and mobility robustness as a function of the UE (User Equipment) mobility are proposed. The suggested solution comprises two key elements, namely enhanced UE MSE (Mobility State Estimation), as well as optimized methods such that high speed users are primarily kept at the macro layer, while the offload to pico cells for low speed users is maximized. The proposed methods are designed as UE autonomous solutions, requiring minimum assistance and signaling from the network. Extensive system level simulations are used to quantify the benefits. Results confirm that the proposed solutions offer improvements in several mobility key performance indicators such as radio link failure, number of handovers, offload to pico layer.

Mobility performance of LTE co-channel deployment of macro and pico cells

This paper aims at analyzing the mobility performance in heterogeneous 3GPP (3rd Generation Partnership Project) Long Term Evolution (LTE) networks. The main objective is to analyze the behavior of LTE macro/pico co-channel networks with different mobility parameters, such as the “Time-To-Trigger” (TTT). For this purpose, a system simulator has been utilized to assess the performance. The system must have different settings depending on the user velocity and on which cell-layer user is being serviced. Additionally, we have considered scenarios with a mixture of users moving freely or constrained to a hotspot, and different pico cell deployments.

GSM/Edge : evolution and performance

Acknowledgements. Acronyms. PART I GSM/EDGE STANDARDIZATION. 1 GSM Standardization History (Guillaume Sebire). 1.1 Introduction. 1.2 History. 1.3 Phase 1. 1.4 Phase 2. 1.5 Phase 2+. References. 2 3GPP Release 7 (Eddie Riddington, David Navratil, Jurgen Hofmann, Kent Pedersen and Guillaume Sebire). 2.1 Introduction. 2.2 EGPRS2. 2.3 Downlink Dual Carrier. 2.4 Mobile Station Receiver Diversity. 2.5 Latency Reductions. References. 3 3GPP Release 8 (Jurgen Hofmann, Vlora Rexhepi-van der Pol, Guillaume Sebire and Sergio Parolari). 3.1 Introduction. 3.2 Interworking with LTE. 3.3 A Interface over IP. 3.4 Multi-Carrier BTS (MCBTS). References. 4 3GPP Release 9 and Beyond (Jurgen Hofmann, Eddie Riddington, Vlora Rexhepi-van der Pol, Sergio Parolari, Guillaume Sebire and Mikko Saily). 4.1 Introduction. 4.2 Voice Evolution. 4.3 Data Evolution. 4.4 H(e)NB Enhancements. 4.5 Security Improvements. 4.6 Local Call Local Switch. References. PART II GSM/EDGE PERFORMANCE. 5 Fundamentals of GSM Performance Evaluation (Mikko Saily, Rauli Jarvela, Eduardo Zacarias B. and Jari Hulkkonen). 5.1 Introduction. 5.2 On the GSM Radio System Performance Engineering. 5.3 Simulation Tools. 5.4 Key Performance Indicators. 5.5 EFL Methodology. 5.6 Further Reading. References. 6 EGPRS2 and Downlink Dual Carrier Performance (Mikko Saily, Kolio Ivanov, Khairul Hasan, Michal Hronec, Carsten Ball, Robert Mullner, Renato Iida, Hubert Winkler, Rafael Paiva, Kurt Kremnitzer, Rauli Jarvela, Alexandre Loureiro, Fernando Tavares and Guillaume Sebire). 6.1 Introduction. 6.2 Overview of GSM Data Performance Evolution. 6.3 EGPRS2 Link Performance. 6.4 EGPRS2 System Performance. 6.5 Downlink Dual Carrier Performance. 6.6 DTM performance. 6.7 GSM Data Evolution Performance Summary. References. 7 Control Channel Performance (Eddie Riddington and Khairul Hasan). 7.1 Introduction. 7.2 Repeated SACCH. 7.3 Repeated Downlink FACCH. References. 8 Orthogonal Sub-Channels with AMR/DARP (Mikko Saily, Jari Hulkkonen, Kent Pedersen, Carsten Juncker, Rafael Paiva, Renato Iida, Olli Piirainen, Seelan Sundaralingam, Alexandre Loureiro, Jon Helt-Hansen, Robson Domingos and Fernando Tavares). 8.1 Introduction. 8.2 Overview of GSM Voice Evolution. 8.3 AMR and SAIC Performance. 8.4 OSC and VAMOS Performance. 8.5 Conclusion. References. 9 Wideband AMR Performance (Robert Mullner, Carsten Ball, Kolio Ivanov, Markus Mummert, Hubert Winkler and Kurt Kremnitzer). 9.1 Overview. 9.2 Introduction. 9.3 Audio Bandwidth Extension for More Natural Sounding Speech. 9.4 End-Users Quality Perception by Listening Tests. 9.5 Impact of AMR-WB on Network Planning. 9.6 Network Quality and Capacity Advantage of AMR-WB over AMR-NB. 9.7 Conclusion. References. 10 DFCA and Other Advanced Interference Management Techniques (Sebastian Lasek, Krystian Majchrowicz and Krystian Krysmalski). 10.1 Introduction. 10.2 Frequency Hopping Basics. 10.3 Intra-Site Interference Management. 10.4 Inter-Site and Intra-Site Interference Management. 10.5 Dynamic Frequency and Channel Allocation. References. 11 Advanced Admission and Quality Control Techniques (Sebastian Lasek, Krystian Krysmalski, Dariusz Tomeczko and Sebastian Lysiak). 11.1 Introduction. 11.2 Quality of Service Management. 11.3 Admission Control. 11.4 Quality Control. 11.5 Performance of the QoS-aware GERAN Networks. 11.6 Enhanced GERAN Performance towards Conversational Services. References. 12 Capacity Enhancements for GSM (Kolio Ivanov, Carsten Ball, Robert Mullner, Hubert Winkler, Kurt Kremnitzer, David Gallegos, Jari Hulkkonen, Krystian Majchrowicz, Sebastian Lasek and Marcin Grygiel). 12.1 Introduction. 12.2 Progressive Power Control for AMR. 12.3 Temporary Overpower. 12.4 Handover Signaling Optimization. 12.5 Separate Radio Link Timeout Value for AMR. 12.6 AMR HR to AMR FR Handover Optimization. 12.7 Service Dependent Channel Allocation. 12.8 Advanced Abis Solutions. References. 13 Green GSM: Environmentally Friendly Solutions (Sebastian Lasek, Krystian Krysmalski, Dariusz Tomeczko, Andrzej Maciolek, Grzegorz Lehmann, Piotr Grzybowski, Alessandra Celin and Cristina Gangai). 13.1 Introduction. 13.2 Energy Optimized Network Design. 13.3 Coverage Improvement Techniques. 13.4 Capacity Improvement Techniques. 13.5 Energy Savings through Software Solutions. 13.6 Energy-Efficient BTS Site. 13.7 Renewable Energy Sources. 13.8 Energy Savings for Controllers and Transcoders. References. PART III EXTENDING THE GSM PARADIGM. 14 GSM in Multimode Networks (Jurgen Hofmann). 14.1 Introduction. 14.2 Standardization of MSR Base Station for Multimode Networks. 14.3 Status in Regulatory Bodies. 14.4 Use of MSR Base Stations in Multimode Networks. References. 15 Generic Access Network: Extending the GSM Paradigm (Juha Karvinen and Guillaume Sebire). 15.1 Introduction. 15.2 Drivers for Convergence. 15.3 GAN Architecture. 15.4 GAN Management Functionality. 15.5 Mobility Features in GAN. 15.6 Voice Service over GAN. 15.7 Supplementary Services and SMS over GAN. 15.8 Packet Switched Data (GPRS) over GAN. 15.9 Emergency Call Support in GAN. 15.10 GAN in 3GPP Releases. 15.11 Implementation Aspects for a GAN-enabled Device. 15.12 Considerations for GAN Deployment. References. Index.

Random Access Capacity Evaluation with Synchronized MTC Users over Wireless Networks

Increased attention has been drawn to machine type communication (MTC) lately, which represents important extension for user functionality in todays technologies, as well as an important potential for marketing expansion. GERAN studies over MTC has mainly focused on applications requiring low throughput and wide coverage such as smart meter, which could cause some impacts over normal data users if operating in a synchronous manner. This paper proposes a new methodology for studying the impact on signaling channels when mixture of synchronous and asynchronous traffic is present in the network. This is based on statistical analysis, considering signaling accessing attempts as driven by a Poisson process. In this approach successive random access attempts by the mobile stations are considered as well as the response on the network side. First implementation is held for GSM/GPRS network, although generalization of the method for other technologies is possible. The simulated results show potential problems to be solved when a large number of synchronized users is present. Additionally, an analysis on the effects of the different levels of synchronization and the addition of extra signaling channels is included. Results also point out possible development paths that could be taken when designing new features to make networks more robust to synchronized traffic.

Overload Control Method for Synchronized MTC Traffic in GERAN

Increasing attention has been drawn in Machine Type Communications (MTC), also known as Machine to Machine (M2M) Communications, since it enables implementation of new services, and expansion of revenue sources for mobile equipment manufacturers and mobile network operators. This potential is high, but some issues have to be solved to enable the wide application of MTC services, especially those which could request connections in a synchronized manner. In GSM networks, synchronized channel requests can result in signaling channel overload, which would delay the access procedure for all users trying to access the network. This paper presents a solution for this problem, in which devices connecting in a periodical manner request a future network access already during a previous connection. Simulation results have shown that by using this technique, overload on the access channels is reduced, improving the access delay of normal users and enabling more MTC devices to be included in the network.

GSM Evolution Importance in Re-Farming 900 MHz Band

Re-farming of 900 MHz band into HSPA has been started and is likely to happen later with LTE. Typically operators have less than 10 MHz block of 900 MHz spectrum and therefore co-existence of two systems in that band is causing challenges. One of the major issues is the high GSM voice traffic that will remain in the GSM network. How to cope the same traffic with significantly less bandwidth for GSM? Orthogonal Sub-Channel (OSC) is a new method to increase voice capacity in the GSM system. OSC intends not only increase the GSM voice capacity but enables very efficient usage of hardware and spectrum resources. In this paper a detailed analysis on OSC performance is made based on system level simulations. Aim is to provide results that show how OSC can be used for refarming of the 900 MHz band into HSPA or LTE. Simulations are carried in the GSM network evaluating capacity for different bandwidths and site configurations. Released frequency spectrum can be used for HSPA or LTE to provide good coverage for rural area mobile broadband. Results show that OSC is an efficient method to release resources for the new systems.

A novel state model for 5G Radio Access Networks

With the trends towards Internet of Things (IoT) and massive Machine-Type Communications (mMTC) it is expected that the 5th Generation of mobile communications (5G) will have a significant amount of battery powered devices (e.g. sensors, baggage tags, etc.). Therefore, battery efficiency and duration will be essential, especially for those devices in remote locations and/or restricted areas. It would be difficult to predict all the 5G use cases, for example, that may arise from IoT however it is expected that for some of these the tradeoff between efficient power savings modes and low-latency system access might be essential. In order to solve this tradeoff, called herein User Equipment (UE) sleeping problem, the paper proposes a novel state model for 5G Radio Access Networks (RAN) that relies on a novel state called “connected inactive” where both the UE and the network does not throw away context information. The state is envisioned to be highly configurable in order to address unpredictable use cases possibly with different requirements. It is shown via protocol signaling diagrams that that the proposed solution enables a quick and lightweight transition from inactive to active data transmission.

GSM voice evolution using orthogonal subchannels

The explosive growth of mobile communications, and the overly crowded and expensive spectrum have pushed both system engineers and operators to make their systems as spectrally efficient as possible in order to accommodate the increasing traffic demand. This article is a tutorial introduction to the orthogonal subchannel (OSC) technique. OSC was adopted to improve the capacity of the GSM/EDGE radio access network GERAN, and it is a new concept in which two users can simultaneously share the same GSM radio resource (time slot and frequency) in both the downlink and in uplink directions. Potentially, OSC could not only provide increased network capacity, but also reduce network-associated costs through more efficient usage of hardware and spectrum resources. In addition, this article presents some challenges related to this method, as well as solutions and their respective impact. The results provided herein may contribute to guidelines for network dimensioning and optimization, as well as list potential enhancements to the OSC radio resource management mechanisms needed to further exploit the benefits of OSC. Currently, in real OSC network deployments a capacity gain of 50 percent has been achieved at the cell level. As an indication of the importance of OSC, GSMA awarded it (called Quad Rate) the Best Technology Breakthrough award at Mobile World Congress 2012 [1].

Resource Allocation Algorithm for GSM-OSC Cellular Systems

We consider one of the latest feature included in the Release 9 of the GSM/EDGE standard: the Orthogonal Sub Channel (OSC) transmission scheme. OSC aims at doubling the cell capacity by multiplexing two co-cell users on the same radio resource. In this work we deal with the challenge of finding the optimum pairing strategy among co-cell OSC users exploiting the Adaptive QPSK (AQPSK) modulation in both up- and down-link scenarios. The aim of the proposed scheduling algorithm is to i) find the best association among the users and the available OSC logical channels, and ii) select the optimum transmitting powers. The criterion for optimization is the minimization of the overall transmitted power constrained to service quality targets. The proposed scheduling algorithm is performed locally at the BS, exploiting channel state information reported by the users. Numerical results show significant power saving provided by the algorithm in heterogeneous scenarios with variable cell load.

Improving the Speech Quality with OSC: Double Full-Rate Performance Assessment

Speech quality is an important measurement for performance evaluation in a wireless mobile communication system since voice is still the most used service on it. The speech quality evaluation in GSM system employing narrowband and wideband AMR codecs with Orthogonal Sub Channel (OSC) technique is addressed in this paper. OSC is a feature proposed in 3GPP GERAN to double circuit switched capacity in GSM networks. It has introduced two new channel modes, namely Double Full-rate (DFR), and Double Half-rate (DHR), which have doubled capacity when compared to legacy AMR channel modes.Many of the efforts in standardization are concentrated on studying hardware improvements lead by AMR DHR usage over AMR HR channel mode. Although AMR DFR has not brought hardware efficiency improvements over legacy channel modes, in this paper it is shown that speech quality is improved over AMR HR with the same blocking capacity; therefore it is a good solution for some interference limited networks. Furthermore, we also investigate the speech quality of wideband AMR DFR codecs which provides a substantial improvement when compared with narrowband AMR.