Lecture Series in Mobile Telecommunications and Networks (1583KB)

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To the edge of chaos? The complexity and the promise of a technology and service-neutral future exaggerated on this slide, for clarity – and this could be their 3G licence. What actually happens in many countries is that they have to pay, give over hard cash, to gain access to the spectrum they want typically long before the market for the product that uses the spectrum emerges. Hence in this case the operators were sitting on £g spectrum unable to use it until sometime later. Essentially, this is the picture of how things are now. And this is the picture of how things could be. We would like to take this cube and think that anyone can use any chunk of spectrum for whatever service they want, and deliver it using whatever technology they want. This slide really depicts a technology and service neutral future in which spectrum is tradable and can fluidly pass from one owner to the next. Think reconfigurable The other cubes in the diagram show some aggregation of spectrum blocks. Large chunks of spectrum become used for a particular service with a particular technology because the market demands that – not because of a decision made in advance. The technology and services that succeed come to the top, rather than somebody on high deciding in advance what those things should be. Of course saying that I know advocating the market place in the current times is not necessarily welcome! And of course there is always the danger – even though I am staying with Utopia for the moment – that this kind of thing happens and nobody wants it, and I suppose we need to recognise that. We can now add reconfigurability to the mix and see what happens. The technologies that are now emerging are adaptive and reconfigurable. With these in mind you can see how a very fluid future might emerge. Suppose I have some spectrum. I buy more, because I need to deliver a greater service to a greater area, and I want more frequencies. Then along comes a competitor. How can the competitor be accommodated? What we see here now on the slide are the spectrum ranges over which each entity can operate. I can operate over a much greater range of frequencies due to superior reconfigurable features and frequency agile hardware in my system. Think different scales What could possibly emerge is the following picture, where the really flexible entity sells some spectrum to the less flexible entity and reconfigures itself to use the remaining spectrum around it. Again, this is a very Utopian way of describing things, in nice neat boxes. But I am trying to present this whole idea of consumers using spectrum as they see fit and consumers making use of reconfigurable technology and hence opening up a different way of thinking about how services might be delivered, and what would happen if spectrum changes hands and is traded from one entity to another. You can also think of spectrum and spectrum management on different scales. At the beginning of this, with my Rubik’s cube, I just arbitrarily put in scales, and this timespan can be quite long – but you can begin to think of it, and take any individual block and sublet and sub-sublet it. The smallest time scale can represent ‘just in time’ spectrum. In the case of the larger blocks, you might talk about large The Royal Academy of Engineering 27
chunks of spectrum where you are interested in more stability, where entities provide services for a longer time. In the case of the smaller blocks end-user devices that get spectrum on a per-session basis. It is very important to keep that kind of scale and timescale in mind – when you read things in this area, they become all jumbled into one timescale and different timescales enable different ways of working. Think different regimes You can also think in terms of different regimes when looking at these cube diagrams. If you look at any one of those cubes and think, ‘I am a spectrum consumer’, then you are not dictating how that spectrum within a cube should be used. The spectrum consumer can operate a commons within the cube for example or any regime they see fit. So this representation is a very general framework, to get people thinking more about a far more fluid way of dealing with spectrum than we currently do. Think more heterogeneously Finally, you could think more heterogeneously than I have depicted the story so far. I am not good at draw so I have not done this completely but essentially all of blocks do not need to have the same size, shape or timespan. The reason for using these diagrams is basically to pose questions about how we management spectrum and to help think about it in a much more fluid form. What, ideally, would that fluid environment look like, and how would we technical achieve this? I need to take a reality check now, because there are many challenges and difficulties in thinking like that. This is another art piece that I saw some time ago, called Digital Shelter, which was created by the artist, Pedro Sepúlveda. Essentially, the whole notion here is that you get a kit – that contains some kind of RF jammer – and you put the jammer down and you tape off an area around the jammer so that you can say, ‘I am free from mobile phone signals in this space.’ This is more conceptual art where people are playing with ideas. I supposes I have been speaking in these very neat terms myself up to now and acting as if transmissions of signals have nice neat borders. In reality, there is a huge amount of interference in the world in which we live. You can have adjacent channels, co-channel interference, intermodulation effects etc. If I take translate these concepts back into the Rubik’s cube like diagrams that I have been drawing, a far more messed up picture would result. So when we compare new and old regimes we see how you can control what frequencies are used where, i.e. frequency re-use distances and the co-channel interference can be managed when there is a single spectrum consumer. Whereas in the very fluid system you have random neighbouring blocks leading to a much more difficult situation. Again here you see how guard bands can help a situation in terms of adjacent channel interference – and are more easily planned when who is using what spectrum to provide which services with a specified technology is known in advance. 28 The Royal Academy of Engineering
Page 1 and 2: Lecture Series in Mobile Telecommun
Page 3 and 4: Foreword This compilation brings to
Page 5 and 6: From wireless networks to sensor ne
Page 7 and 8: From wireless networks to sensor ne
Page 9 and 10: As far as the routing of packets is
Page 11 and 12: easons. In the internet, one never
Page 13 and 14: Implementation with laser pointers,
Page 15 and 16: here of laptops, and all these lapt
Page 17 and 18: adds a great deal of discrete compl
Page 19 and 20: Questions & Answers Mike Walker: Th
Page 21 and 22: Human beings will also evolve and w
Page 23 and 24: Welcome and introduction Professor
Page 25 and 26: ComReg Collection - Start 16/Apr/20
Page 27: evidence that people give in favour
Page 31 and 32: As an aside, I was reading a few of
Page 33 and 34: Of course, it is not just one mask,
Page 35 and 36: I apologise for hopping between top
Page 37 and 38: Questions & Answers Michael Walker:
Page 39 and 40: Nobody - believe you me, it came ou
Page 41 and 42: The second aspect of my comment is
Page 43 and 44: want to call it - that sits there a
Page 45 and 46: From plain old Telephony to flawles
Page 47 and 48: From plain old Telephony to flawles
Page 49 and 50: You can see that there is much room
Page 51 and 52: 1024, we transmit 10 bits, so to sp
Page 53 and 54: Bandwidth extension with hidden sid
Page 55 and 56: 4 Vision: ambience audio communicat
Page 57 and 58: Questions & Answers Michael Walker:
Page 59 and 60: I said five years ago and what I he
Page 61 and 62: them and perhaps leave out some of

Lecture Series in Mobile Telecommunications and Networks (1583KB)

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