The Tactile Internet has highly challenging technical requirements. For example, the end-to-end latency for the sensation of touch to be realistically conveyed to the end-user via communications, for the purpose of that end-user implementing control actions in response to that touch, must be less than 1 ms. This is equivalent to only 300 km propagation at the speed of light. Such constraints mean that many of the conventional approaches to communications, e.g., higher-layer retransmissions for reliability and congestion control, and even link-level retransmissions for reliability, can not apply. In this paper, we propose a novel solution for combining licensed access for reliability and control, with virtualized low-frequency sub-GHz access for good coverage and low latency, also removing receive-acknowledgement based reliability and congestion control mechanisms. Through the removal of these reliability/retransmission mechanisms, and by achieving a more direct path to the receivers through virtualization and better coverage maximizing (wireless) routing options, or even transmitting directly, this proposed solution minimizes latency and jitter while still being able to achieve the extremely challenging requirement for reliability of the Tactile Internet. We argue the benefits of our solution with reference to a major trial within the Ofcom TV White Spaces Pilot in the UK, as one readily-available means for such sub-GHz transmission. We also provide the example of such a realization as a viable means of achieving remote surgical operations across the London, UK area, with the surgeon(s) being physically located in only one or a small number of London hospitals.
['Oliver Holland', 'Stan Wong', 'Vasilis Friderikos', 'Zhijin Qin', 'Yue Gao']
Virtualized sub-GHz transmission paired with mobile access for the Tactile Internet