Edge Caching and Computing in 5G for Mobile AR/VR and Tactile Internet

As a result of increasing popularity of augmented reality and virtual reality (AR/VR) applications, there are significant efforts to bring AR/VR to mobile users. Parallel to the advances in AR/VR technologies, tactile internet is gaining interest from the research community. Both AR/VR and tactile internet applications require massive computational capability, high communication bandwidth, and ultra-low latency that cannot be provided with the current wireless mobile networks. By 2020, long term evolution (LTE) networks will start to be replaced by fifth generation (5G) networks. Edge caching and mobile edge computing are among the potential 5G technologies that bring content and computing resources close to the users, reducing latency and load on the backhaul. The aim of this survey is to present current state-of-the-art research on edge caching and computing with a focus on AR/VR applications and tactile internet and to discuss applications, opportunities and challenges in this emerging field.

Augmented reality and virtual reality (AR/VR) technologies have recently gained noticeable attention both from academia and industry. The concept of AR is to present virtual information over the reality such as deformation of real images, whereas in VR, the main idea is to place users in a virtual environment. In some applications, it is possible to observe a mix of AR and VR technologies where virtual and actual environments are smoothly combined. Despite the technology leap in the recent years, current state-of-the-art AR and VR technologies suffer from various deficiencies. For instance, the headsets are not able to track eye movements, facial expression and senses cannot be detected in details. More importantly, current AR and VR systems are widely limited to offline streaming where 360° navigable scenes are rendered using a powerful external computer to which the AR/VR device is attached to a cable. In addition, the majority of AR/VR applications do not support real-time interaction of multiple mobile users which is due to technology bottleneck in today's wireless networks. Mobile AR/VR applications require intensive computational capability and massive communication bandwidth with ultra-low latency to transmit high resolution/frame-rate videos that cannot be handled with current wireless infrastructure [i.e., long term evolution (LTE) networks].