Workshop on Small Cell and 5G Networks (SmallNets)

Monday, 8 June 2015 • 09:00 – 18:00

WS-03: Small Cell and 5G Networks (SmallNets)

Organizer: Walid Saad (Wireless@VT, Virginia Tech, USA)

The demand for high-speed wireless access is expected to grow significantly in the foreseeable future. The emergence of new services such as mobile video streaming leads to stringent requirements on the quality-of-service that next generation wireless networks must deliver. This has urged wireless and mobile operators to examine new ways for improving their coverage, boosting their network's capacity, and lowering their expenditures. A promising approach to solving this problem is through network densification via the massive deployment of Small Cell Networks (SCNs). SCNs will enable next-generation networks to provide seamless, high-quality wireless access. Combined with emerging paradigms such as millimeter wave communication, SCNs are expected to lie at the heart of 5G wireless systems. This workshop will bring together academic and industrial researchers in an effort to identify and discuss the major technical challenges and recent results related to small cell and 5G networks.

Welcome Session

Keynote-1: Future Evolution of Small Cell Networks

Cellular traffic demand has been increasing exponentially over the past years, and current traffic forecasts indicate that this trend will continue with an expected 10x increase in the demand within the next 5 years. However, average revenues per user are declining, and energy consumption of networks already accounts for 1-2% of a country's total energy consumption. As a result meeting the future capacity demand with traditional macrocellular networks is infeasible. In recent years it has been widely recognized that deploying small cells are a key component to addressing the capacity problem, and today the number of deployed small cells has already exceeded the number of macrocells worldwide. In this presentation the limits of scaling capacity further by densification and alternative means such as using more spectrum and more antennas are explored. It is shown that we are still far from reaching the limits of densification. However, with increasing the number of cells, cost-effective deployment and management becomes paramount. Therefore, self-optimization is a key enabler for large scale deployments. Joint optimization of CellID, coverage and idle modes in a multi-vendor scenario is discussed as one example. Finally the impact of small cells on the energy efficiency of networks is discussed, and it is shown that when efficient idle modes are implemented, energy consumption is not a limiting factor anymore.

Modeling and performance analysis

Error Performance Analysis in K-tier Uplink Cellular Networks using a Stochastic Geometric Approach
Laila Hesham Afify and Hesham ElSawy (King Abdullah University of Science and Technology (KAUST), Saudi Arabia); Tareq Y. Al-Naffouri (King Abdullah University of Science and Technology, USA); Mohamed-Slim Alouini (King Abdullah University of Science and Technology (KAUST), Saudi Arabia)
pp. 87-93
A Cooperative Channel Estimation Approach for Coordinated Multipoint Transmission Networks
Qianrui Li (EURECOM, France); David Gesbert (Eurecom Institute, France); Nicolas Gresset (Mitsubishi Electric Research Centre Europe, France)
pp. 94-99
Jointly Optimal Spectrum Deployment and Cognitive Access for ASE Maximization of Macro-Femto HetNets
Lu Yang, Shenghui Song and Khaled B. Letaief (The Hong Kong University of Science and Technology, Hong Kong)
pp. 100-105

Flexible Duplexing Techniques and User Association

Hybrid Division Duplex for HetNets: Coordinated Interference Management with Uplink Power Control
Mehrnaz Afshang (Nanyang Technological University, USA); Zeinab Yazdanshenasan (Nanyang Technological University, Singapore); Sayandev Mukherjee (DOCOMO Innovations Inc., USA); Peter Han Joo Chong (Nanyang Technological University, Singapore)
pp. 106-112
A Centralized Algorithm for Dynamic TDD Frame Reconfigurations in Synchronized HetNets
Khanh Nguyen, Luca Zappaterra and Hyeong-Ah Choi (The George Washington University, USA)
pp. 113-118
An Interference-Aware Distributed Transmission Technique for Dense Small Cell Networks
Nurul H. Mahmood and Gilberto Berardinelli (Aalborg University, Denmark); Klaus Pedersen (Nokia Siemens Networks, Denmark); Preben Mogensen (Nokia Siemens Networks, Aalborg, Denmark)
pp. 119-124
Efficiency Analysis of Downlink and Uplink Decoupling in Heterogeneous Networks
Katerina Smiljkovikj (Ss. Cyril and Methodius University in Skopje, Macedonia, the former Yugoslav Republic of); Liljana Gavrilovska (Ss Cyril and Methodius University - Skopje, Macedonia, the former Yugoslav Republic of); Petar Popovski (Aalborg University, Denmark)
pp. 125-130
Dynamic Power and Layer Selection for Scalable Video Streaming in Femtocell Networks
Peng Si, Youkang Shi, Ruiyi Zhu, Jian Yang and Hong-Sheng Xi (University of Science and Technology of China, P.R. China)
pp. 131-135

Keynote-2: Femto-caching and device-to-device collaboration for wireless video networks

The ongoing explosive increase in the demand for video content in wireless networks requires new architectures to increase capacity without excessive costs. The talk will present a new architecture for solving this problem, exploiting a special feature of video viewing, namely asynchronous reuse. The approach is based on (i) distributed caching of the content in femto-basestations with small or non-existing backhaul capacity but with considerable storage space, called helper nodes, and/or (ii) usage of the wireless terminals themselves as caching helpers, which can distribute video through device-to-device communications. The talk will discuss the fundamental principles, scaling laws for the throughput, as well as practical implementation considerations. The new architecture can improve video throughput by one to two orders-of-magnitude.

Keynote-3: Comparing Massive MIMO at Sub-6 GHz and Millimeter Wave

Fifth generation cellular systems are going massive in the number of antennas at the base station. But will this happen at sub-6 GHz or millimeter wave frequencies? This presentation compares massive MIMO at sub-6GHz and millimeter wave frequencies. Based on stochastic geometry, a common mathematical framework is proposed to analyze SINR and rate distributions for downlink and uplink in both systems. Differentiating features between sub-6GHz and millimeter wave systems are incorporated by particular modeling assumptions. The analysis of sub-6GHz systems shows that to maintain the same SINR and rate distribution per user, the number of base station antennas should scale superlinearly with the number of scheduled users in a cell, as a function of the path loss exponent. Numerical results for the millimeter wave studies indicate that due to the presence of building blockages, a base station deployment is required to achieve a fair SINR coverage. The comparison concludes that while the benefits of going massive are confirmed for both systems, the advantage goes to sub-6 GHz for sparse deployments and to millimeter wave for dense deployments.

Interference and mobility management, D2D

Designing Wireless Broadband Access for Energy Efficiency: Are Small Cells the Only Answer?
Emil Björnson (Linköping University, Sweden); Luca Sanguinetti (University of Pisa & SUPELEC, Italy); Marios Kountouris (Huawei Technologies, France)
pp. 136-141
Using more channels can be detrimental to the global performance in interference networks
Chao Zhang (University paris sud, France); Samson E Lasaulce (CNRS - Supelec, France); Elena Veronica Belmega (ETIS / ENSEA - UCP - CNRS, France)
pp. 142-147
Dynamic Cell Muting for Ultra Dense Indoor Small Cell Deployment Scenario
Wang Xiaoyi (Nokia Networks, USA); Eugene Visotsky (Nokia Siemens Networks, USA); Amitava Ghosh (Nokia Networks, USA)
pp. 148-153

Poster Session 1 - Optimized Transmission Design

Self-Optimization of Uplink Power and Decoding Order in Heterogeneous Networks
Mathew Pradeep Goonewardena (University of Quebec & École de Technologie Supérieure, Canada); Animesh Yadav (UQAM, Canada); Wessam Ajib (Université du Québec à Montréal, Canada); Halima Elbiaze (University of Quebec at Montreal, Canada)
pp. 154-159
Filtered Multitone Transmission with Variable Subcarrier Bandwidths
Guanping Lu (Shanghai Jiaotong University, P.R. China); Jinsong Wu (Universidad de Chile, Chile); Rendong Ying (Shanghai Jiaotong University, P.R. China)
pp. 160-165
Simplicial homology based energy saving algorithms for wireless networks
Ngoc Khuyen Le (Telecom ParisTech, France); Philippe Martins (Telecom Paristech, France); Laurent Decreusefond (Telecom ParisTech & CNRS LTCI, France); Anaïs Vergne (Telecom ParisTech, France)
pp. 166-172
Modular IPM Strategy for Energy Conservation in Densely Deployed Networks
Kyounghye Kim (KAIST, Korea); Nah-Oak Song (Korea Advanced Institute of Science and Technology (KAIST), Korea); Peng-Yong Kong (Khalifa University of Science, Technology & Research, UAE); Junhyuk Kim and June-Koo Kevin Rhee (KAIST, Korea)
pp. 173-178
Impact of Mobility on QoS in Heterogeneous Wireless Networks
Mikaël Touati (Orange Labs & Telecom ParisTech, France); Jean-Marc Kelif (Orange Labs, France); Marceau Coupechoux (Telecom ParisTech, France)
pp. 179-184

Poster Session 2 - Coordination and Cooperation

Bi-directional Signaling for Dynamic TDD with Decentralized Beamforming
Laddu Praneeth Roshan Jayasinghe, Antti Tölli and Jarkko Kaleva (University of Oulu, Finland); Matti Latva-aho (UoOulu, Finland)
pp. 185-190
Handling Real-Time Video Traffic in Software-Defined Radio Access Networks
Ngo. c-D˜ung Ðào (Huawei Technologies Canada Co., Ltd., Canada); Hang Zhang (Huawei, Canada); Hamid Farmanbar (Huawei Technologies Canada Co., Ltd., Canada); Xu Li and Aaron Callard (Huawei, Canada)
pp. 191-196
Mode Selection for CoMP Transmission with Quasi Timing Synchronization
Zheqi Gu, Ning Wei and Zhongpei Zhang (University of Electronic Science and Technology of China, P.R. China)
pp. 197-202
The Effect of Out of Cluster Interference on Coordinated Beamforming in LTE-A HetNets
Jakob Belschner (Telekom Innovation Laboratories, Germany); Veselin Rakocevic (City University London, United Kingdom); Joachim Habermann (Technische Hochschule Mittelhessen, University of Applied Sciences, Germany)
pp. 203-209

D2D, Energy efficiency and Backhaul Issues

Mode Selection, User Pairing, Subcarrier Allocation and Power Control in Full-Duplex OFDMA HetNets
Radwa Aly Sultan (University of Houston, USA); Lingyang Song (Peking University, P.R. China); Karim G Seddik (American University in Cairo, Egypt); Yonghui Li (University of Sydney, Australia); Zhu Han (University of Houston, USA)
pp. 210-215
User Clustering for High-Speed Small Cell Backhaul over Coaxial Cable
Haleema Mehmood and John Cioffi (Stanford University, USA)
pp. 216-221
Guard Zone Based D2D Underlaid Cellular Networks with Two-tier Dependence
Zheng Chen (CentraleSupélec - CNRS - Université Paris Sud, France); Marios Kountouris (Huawei Technologies, France)
pp. 222-227

Panel-1 : Is 5G solely an Ultra Dense Network (UDN) technology? Which technologies will survive the 5G "hype" and blossom?

The panel will discuss the technologies that are bound to become an integral part of 5G networks. In particular, it will discuss whether ultra dense networks will be the foundations of 5G while shedding light on which technologies will survive the 5G hype.