5G for the Connected World

3Radio Access Technology

Sami Hakola¹, Toni Levanen², Juho Pirskanen³, Karri Ranta‐aho³, Samuli Turtinen¹, Keeth Jayasinghe⁴, and Fred Vook⁵

¹Nokia, Oulu, Finland

²Tampere University, Tampere, Finland

³Wirepas, Tampere, Finland

⁴Nokia, Espoo, Finland

⁵Nokia, Naperville, USA

3.1 Evolution Toward 5G

3.1.1 Introduction

Cellular technologies have developed tremendously in past decades. The global system for mobile communications (GSM) technology as the best known 2G technology was highly successful for voice service, changing completely our way of communicating over telephone and being available everywhere and at any time. GSM also laid the foundation for cellular data services with the introduction of general packet radio service (GPRS). The 3G, i.e. Universal Mobile Telecommunications System (UMTS) with High Speed Downlink Packet Access (HSDPA) and High Speed Uplink Packet Access (HSUPA) features, started the real data boom with variety of different data applications in devices. At the same time different companies introduced new mobile phone types, more capable for data communication with different data application compared to earlier generation smartphones and without a real keypad like the iPhone. This data boom was further emphasized by introduction of Long‐Term Evolution (LTE) and formally 4G with Long‐Term Evolution Advanced (LTE‐A) features. The development in cellular technologies as well as development in wireless local area networks (WLANs), i.e. WLAN802.11 changed our thinking ...