To white space or not to White Space: That is the trial within the Ofcom TV White Spaces pilot

摘要

TV White Space (TVWS) has taken a big step forward with the UK regulator Ofcom initiating a pilot of the technology in the UK, based on rules for White Space Devices (WSDs) standardized and harmonized at the European level by ETSI. This paper reports on a subset of the work undertaken by our large-scale trial within the Ofcom Pilot, investigating what is achievable in TVWS in terms of availability and capacity, and strongly focusing on the potential to aggregate white space resources. Moreover, this paper provides some experimental results and observations from our trial, particularly around issues such as performance testing and assessment of appropriate scenarios for TVWS deployments. Some of the key observations in this paper, among numerous others, include: (i) In the UK, it seems likely that TVWS has most performance/benefit potential in below-rooftop receiver and indoor/underground deployments. For availability and capacity analyses, we particularly define and assess TVWS scenarios that we term as ???mobile broadband downlink??? and ???indoor wireless local-area networking??? based on this realization. We further demonstrate the strength of TVWS for indoor communications through a range of challenging experiments inside the Strand Campus of King's College London. (ii) There is ample TVWS available in much of the UK and particularly in the London area, although this is affected greatly by the scenario that is considered and can be very highly variable. The mobile broadband downlink scenario is particularly affected by availability reduction and variability outside of the London area. Impressive capacities can be achieved by optimal aggregation in TVWS. Achievable area capacity in TVWS is high. (iii) In a number of cases, and particularly under some aggregation scenarios, subsets or indeed all WSD spectrum mask classes give similar performance. (iv) A worst case 700 MHz spectrum reassignment for ITU Region 1 in WRC 2015 could significantly affect availability/- apacity in some TVWS usage scenarios, for lower quality spectrum mask class WSDs.