“31. I intend to apply that approach. I take particular note of: i) The requirements not to be unfair to the patentee by allowing an artificially narrow definition, or unfair to the public (and the defendant) by going so broad as to “dilute” the CGK. Thus, as Counsel for Alcon accepted, there is an element of value judgment in the assessment. ii) The fact that I must consider the real situation at the priority date, and in particular what teams existed. iii) The need to look for an ‘established field’, which might be a research field or a field of manufacture. iv) The starting point is the identification of the problem that the invention aims to solve.” 32. In the present case, the problem that the invention aims to solve is not in dispute: it is a narrow one of how to allocate PDCCH search spaces. 33. The established field in which this problem was in fact located was RAN1. The PDCCH was not a field in its own right. Prof Lozano accepted that no one would have had a scope of work that matched it. It was too narrow for that. There was no RAN1 sub-group or sub-plenary devoted to it. 34. Thus I reject Apple’s argument that the skilled person would have been a PDCCH person in the sense Apple meant that. It is a “blue Venezuelan razor blade” kind of argument (see [62] in Illumina ), though not nearly as extreme in degree as that imaginary example. 35. Optis’ view of the skilled person has the benefit that RAN1 clearly was an established field, and that the problem that the invention aims to solve is within its scope. 36. However, in my view Optis treated the analysis that the skilled person is a RAN1 person as an opportunity to carry out some inappropriate dumbing-down through dilution, of the kind deprecated in Mayne v. Debiopharm[2006] EWHC 1123 (Pat) and cited by Birss J in Illumina and recognised by me in Alcon . RAN1 is a broad umbrella and probably no one real person had the knowledge, skills and experience to cover the whole of its field. One can see that by the number of people participating in the discussions, and by the fact that major companies had teams on RAN1, either attending as delegates or participating in the background. 37. Where this is of potential practical importance in the present case is in Optis’ contentions that the skilled person would not be comfortable with, for example and in particular, modular arithmetic, or hashing functions/random numbers. This was basically a submission that the skilled person would lack the basic tools to do the task which Ericsson set - to assess its function and then improve it if necessary. The submission was rather grounded in the idea of the skilled person being an individual spread so thin across RAN1 that their CGK on any particular aspect of it must be very shallow. For the reasons I have just given, I reject this as a matter of principle and on the facts. 38. My conclusion in this respect is supported by the principle expressed by Pumfrey J in Horne v. Reliance[2000] FSR 90 (also cited in Illumina ) that the attributes of the skilled person may often be deduced from assumptions which the specification clearly makes about their abilities. In the present case the specification of the Patents gives the skilled person some parameters for use as A, B and D in the LCG of the claims, but it assumes that with only the modest amount of help that the specification gives, the skilled person would be able to find more options for the parameters if they wanted to. 39. Thus I conclude that the skilled person in this case is a “RAN1 person” of the kind attending meetings or providing back-up, with the aptitudes and CGK appropriate to the tasks that RAN1 would require of them. In real life, as I say, the organisations involved will have had multiple people to give this coverage, but in the present case I can refer in the singular to “the skilled person”. 40. While the “dilution” point is of potential general importance, the RAN1 v PDCCH point only matters for the case over Knuth, since Optis accepts that the RAN1 skilled person starting from Ericsson would know or look up the material relied on by Apple. The common general knowledge 41. There was no dispute as to the applicable legal principles: to form part of the CGK, information must be generally known in the art, and regarded as a good basis for future action. It is not a requirement for CGK that the skilled person would have memorised it; CGK includes information that the skilled person would refer to as a matter of course. 42. In relation to obviousness, the Court also may have regard to information which the skilled person would acquire as a matter of routine if working on the problem in question. Information of that kind is not CGK as such (although the effect may be very similar) but rather may be taken into account because it is obvious to get it. See KCI v. Smith & Nephew[2010] EWHC 1487 (Pat) at [108]-[112], approved on appeal at [2010] ECWA Civ 1260. 43. As is now usual, the parties submitted a document setting out the agreed matters of CGK, which I have used as the basis for the next section of this judgment. Where I have removed material it is because I think it of low relevance, not because I disagree with it. 44. The section on “Collisions and Blocking” was produced during trial after I asked what the position was on the state of CGK on that topic. Its contents are not accepted by Optis as being CGK because Optis (successfully) disputed that the skilled person is a PDCCH person (see above), but Optis does accept that its contents would be “apparent” to a RAN1 person reading Ericsson or “otherwise tasked specifically with the problem of control signalling on the PDCCH”. 45. I take this to mean that the contents of the section can by agreement be treated as CGK for the practical purposes of the case starting from Ericsson, and that is how the argument proceeded. In some cases it could be important that information found by routine research would not be known to the skilled person right at the outset of their consideration of the prior art, but only after they had identified a problem. But in the present case the skilled person would acquire the information about collisions and blocking straight away, since it is necessary to understanding Ericsson. 46. There was also a dispute about the relevant sources of CGK. Usually, CGK is proved by means of well-established textbooks and the like. In this field there was no textbook specific to LTE. But in any event, the dispute was really about the path from Ericsson to Knuth, and I deal with it in the context of obviousness. At this stage I merely observe that what one is considering is whether particular information was CGK; it is legitimate for a party to put forward materials as examples of how information would be obtained, without necessarily saying that those materials are themselves CGK. Agreed common general knowledge Background to LTE and RAN1 47. LTE stands for “Long Term Evolution” and is (or at least became) a “fourth generation” (4G) Radio Access Network (RAN). It succeeded the second and third generation systems (2G and 3G). It was driven by EU, US, Chinese, Japanese, South Korean and (to some extent) Indian initiatives. 48. In 3GPP, Technical Specification Group (TSG) RAN Working Group 1 (RAN1) is responsible for the physical layer (L1) specifications. 49. There was no actual LTE network at the Priority Date (19 February 2008 ). The first technical specifications defining LTE were published in 2007 as part of Release 8, which was the Release current at the Priority Date. Division of radio resources within a cellular network 50. In a cellular communications system, a “resource” is a term used to refer to the way in which the radio spectrum is divided up and allocated so that different transmissions can be distinguished from one another. Resources can be defined in different ways, such as by a given period of time, at a particular frequency, or using particular codes. 51. In LTE, as with other cellular systems, the radio resource is divided between resources used for transmissions from UEs (i.e. mobiles) to the eNodeB (i.e. base station), which is referred to as the “uplink”, and resources used for transmissions from the eNodeB to UEs, referred to as the “downlink”. 52. In addition to the division between uplink and downlink transmissions, cellular networks also need a way of allocating resources between transmissions from and to different UEs, and between transmissions on different channels (e.g., those for sending control information or user data). These techniques are referred to as multiple access technologies. Protocols and Layers 53. A common way of conceptualizing mobile communications systems is the Open Systems Interconnection (OSI) model. The OSI model divides the processes by which data is transmitted and received into different protocol ‘layers’, in which each layer relates to particular functionality. A group of layers that communicate with each other to transmit and receive data is referred to as a protocol “stack”
“63. Of particular importance in this case, in view of the way that the issue has been developed by the parties, is the difference between the plodding unerring perceptiveness of all things obvious to the notional skilled man and the personal characteristics of real workers in the field. As noted above, the notional skilled man never misses the obvious nor sees the inventive. In this respect he is quite unlike most real people. The difference has a direct impact on the assessment of the evidence put before the court. If a genius in a field misses a particular development over a piece of prior art, it could be because he missed the obvious, as clever people sometimes do, or because it was inventive. Similarly credible evidence from him that he saw or would have seen the development may be attributable to the fact that it is obvious or that it was inventive and he is clever enough to have seen it. So evidence from him does not prove that the development is obvious or not. It may be valuable in that it will help the court to understand the technology and how it could or might lead to the development. Similarly evidence from an uninspiring worker in the field that he did think of a particular development does not prove obviousness either. He may just have had a rare moment of perceptiveness. This difference between the legal creation and the real worker in the field is particularly marked where there is more than one route to a desired goal. The hypothetical worker will see them all. A particular real individual at the time might not. Furthermore, a real worker in the field might, as a result of personal training, experience or taste, favour one route more than another. Furthermore, evidence from people in the art as to what they would or would not have done or thought if a particular piece of prior art had, contrary to the fact, been drawn to their attention at the priority date is, necessarily, more suspect. Caution must also be exercised where the evidence is being given by a worker who was not in the relevant field at the priority date but has tried to imagine what his reaction would have been had he been so.” 185. And there are many general statements in the authorities stressing that secondary evidence is, indeed, secondary . E.g. Molnlycke v Procter & Gamble[1994] RPC 49 at 112: “Secondary evidence of this type has its place and the importance, or weight, to be attached to it will vary from case to case. However, such evidence must be kept firmly in its place. It must not be permitted, by reason of its volume and complexity, to obscure the fact that it is no more than an aid in assessing the primary evidence.” 186. Not infrequently, secondary evidence may be rejected simply because the workers in the field in question were not aware of the cited prior art (or it is unknown if they were aware of it). That does not apply here. The RAN1 workers in question were specifically aware of Ericsson and were working on it. So subject to the other caveats identified above, this is a case where the secondary evidence could be more likely than usual to play a role. 187. Another factor clearly established in the case law in relation to “why was it not done before” is the closeness in time between the prior art and the making of the invention. As Jacob LJ commented in Schlumberger v EMGS[2010] RPC 33 at [77]: “[Secondary evidence] generally only comes into play when one is considering the question ‘if it was obvious, why was it not done before?’ That question itself can have many answers showing it was nothing to do with the invention, for instance that the prior art said to make the invention obvious was only published shortly before the date of the patent, or that the practical implementation of the patent required other technical developments.”
“28. Where, however, the patentee merely patents an old idea thought not to work or to be practical and does not explain how or why, contrary to the prejudice, that it does work or is practical, things are different. Then his patent contributes nothing to human knowledge. The lion remains at least apparent (it may even be real) and the patent cannot be justified.” 190. Optis responded by citing the decision of Mann J in Buhler v. Spomax[2008] EWHC 823 (Ch) . Mann J cited the above passage in Pozzoli , and also referred to what Jacob LJ had said when a judge at first instance in Union Carbide v. BP[1998] RPC 1 , that invention can lie in “ finding out that that which those in the art thought out not to be done, ought to be done .”
“Q. And they would see the same things that we have just discussed, so they would see the problem of the continuing collisions between subframes and they would see the problem of C=16 if they put some numbers in? A. Certainly the C=16 I would suggest they would. The other one you would have to get the right UEIDs to find that to work, but yes. Q. So whether the skilled person just eyeballs the Ericsson function, if I can put it like that, or whether they put some numbers in, then they are going to see that the Ericsson function does not have the desired properties? A. Ultimately, probably they will come to that conclusion, yes.” 214. Optis sought to meet this in two main ways. First, it said that the secondary evidence showed that the “lockstep” problem (see below) was not an obvious one, and second it said that Ms Dwyer’s cross-examination as referred to above was about “could” and not “would”
“So, my Lord, a hashing function has two purposes. One is to map a big number of inputs down to a smaller number of outputs, so there is a squeezing process, and the other one is to randomise these mappings so that two very similar inputs do not get mapped to two very similar outputs to minimise confusions. So the mod C, the outer mod C, is doing the squeezing down part of the hashing, and it is a standard way of doing it. It has been used in 3GPP before. It had been proposed already many months before the priority date to do this squeezing down by Motorola, and it is actually in Ms. Dwyer's report. So that is well understood, the squeezing down. The discussion here, and the work that was taking place, was around the randomisation part, the randomisation part. So the randomisation part here is K x+L, right, because the rest is the mod C which is doing the squeezing down, concentrating the many input into the few outputs. So randomisation is done by K x+L and is not doing a good job at that.” 224. Later, he said: “Well, like I said, the Skilled Person here is looking for something that randomises properly; that is it. That is all that is missing here. The rest is fine. The outputs are 0 to C-1 as they should be, so that part is functioning well. What is not functioning well is the randomisation part, so one would look to randomise things so you look at the book and see what it says about the number generators and pick an off-the-shelf solution.” 225. I accept this and think that while the skilled person would certainly have to think about the overall effect of the whole function, it would stand out clearly that the mod C part had the object and effect for which Apple contends. It would not require insight to retain mod C if possible (there is a specific point about using mod C which interfaces with the issues on the specified claims and with which I deal below). 226. Ms Dwyer came close to accepting much of this. She accepted that mod C would be seen as having the “squeezing down” effect to which I have referred. She said “ I think people would look to change part of the equation, agreed, and the mod C does map the output to the range that is desired. So I think that if they were trying to keep it similar to the original format that is true. ” 227. I therefore accept Apple’s contention that an obvious route was to retain mod C, on the basis that it was adequately performing a well-understood and necessary task, and look to remedy the problem, apparent at this stage, with the Kx + L randomisation part. Literature search 228. With work focusing on changing (K*x + L), Apple’s case was that the skilled person would look in the literature for an appropriate RNG, and find LCGs in Knuth or other sources. 229. Ms Dwyer resisted strongly the proposition that the skilled person would look online or in a textbook for a RNG to replace (K*x + L). She said that was a leap and another simpler approach would be just to change x, which she said some of the RAN1 participants had looked at. Against that background she was asked whether it would be a reasonable or sensible route for the skilled person to look up an RNG. She replied that they could take that route. 230. Unsurprisingly, Counsel for Optis submitted that “could” was not good enough. I agree that in itself it is not, but my task is to weigh the evidence of Prof Lozano who clearly said that is what the skilled person would do (there being other possibilities, of course, and I have to weigh that up as well), against the evidence of Ms Dwyer who would not go that far, although my sense at the time was that she was as close as may be to accepting “would”. 231. I prefer Prof Lozano’s evidence; I found him the more persuasive expert for reasons given in my overall assessment of the witnesses above. One sensible thing to do would be to look in the literature for an established and understood way to generate randomness. I think it would be the most natural way forward, and certainly one of the leading ones. It is the reliable, routine, systematic approach of the uninventive skilled person. 232. Prof Lozano was fair in putting this forward. He did not reject other options as being possible. Ms Dwyer’s idea of modifying x was not really explored with him, but he was asked about the possibility of varying K and/or L by subframe, the idea put to him being that it would create more decorrelation between subframes. Prof Lozano agreed that changing K and/or L this way was something that the skilled person might do, and indeed it was discussed in RAN1 (suggested by Dr Parkvall). 233. I do not think the existence of such other options makes it any less natural or obvious that the uninventive skilled person would look for an established RNG. The Ericsson function had turned out to be bad for the task in hand; it was not of an existing type that was well-understood; the ideas of varying x or K and/or L were fine as concepts but the skilled person would not have had guidance from the CGK as to how to do it, so it seems a good deal less likely to appeal than looking to standard literature. Getting to Knuth 234. Apple’s key point was that by one means or another, having embarked on a literature search, the skilled person would find their way to Knuth. 235. I accept this. Knuth is a standard reference work, a “bible”, and it is possible that the skilled person might get to it just by asking a librarian or similar. Apple’s case, though, was built on the skilled person taking either Wikipedia as a jumping-off point, or using NRC and getting to Knuth that way. 236. Prof Lozano specifically said that he thought NRC would be the most natural thing to turn to first, and since he himself had it on his shelves, that is what he did. I accept that that is what he did, and that it is representative of what the skilled person might well do. 237. However, there is a significant complication, which is that Prof Lozano had the second edition of NRC on his shelves, and there was a third edition, which he did not have, and which was published six months before the priority date. The difference is of great significance potentially, because the third edition strongly deprecates LCGs in ways which the second edition did not. I address this below. 238. No criticism is made of Prof Lozano personally for finding only the second edition of NRC (whereafter he was led to check out Knuth from his University library), but the legal issue for me is what was CGK to the notional skilled person. I have no doubt that the CGK will usually include the latest edition of established standard works, except perhaps in marginal cases where the latest edition is published very shortly before the priority date. That is not the case here. Apple’s case was that NRC was a CGK source, and it must live with the consequences that that must include the third edition, warts and all. Apple argued that the second edition did not stop being CGK. I do not accept that and it seems an impractical and unreal route to start down for patent cases generally, but it makes little or no difference because what the third edition makes clear is that the attitude of the art to LCGs was worsening over time. From here on where I refer to NRC I mean the third edition. 239. For these reasons, I think the CGK attitude to LCGs must be assessed from NRC, Knuth and, to a significantly lesser extent, Wikipedia. I accept Ms Dwyer’s evidence that the skilled person would not use Wikipedia as a sole source of specific functions, formulae or analysis, but she accepted that it was a useful starting point for finding something reliable, and there is a clear pointer to Knuth in it. 240. The third edition of NRC came into the case late; Counsel for Optis told me, and I accept, that it was only found shortly before trial because Optis had no reason to think Prof Lozano would not have used the latest edition. Accordingly, neither he nor Ms Dwyer put in written evidence on it specifically. 241. NRC Chapter 7 deals with random numbers. The last paragraph on page 340 and the first paragraph on page 341 say: “The pragmatic point of view is thus that randomness is in the eye of the beholder (or programmer). What is random enough for one application may not be random enough for another. Still, one is not entirely adrift in a sea of incommensurable applications programs: There is an accepted list of statistical tests, some sensible and some merely enshrined by history, that on the whole do a very good job of ferreting out any nonrandomness that is likely to be detected by an applications program (in this case, yours). Good random number generators ought to pass all of these tests or at least the user had better be aware of any that they fail, so that he or she will be able to judge whether they are relevant to the case at hand. For references on this subject, the one to turn to first is Knuth. Be cautious. about any source earlier than about 1995, since the field progressed enormously in. the following decade.” 242. This illustrates an important facet of Apple’s argument, which is that the skilled person would make a case-specific decision about how much randomness was needed. There is also a clear signpost to Knuth. 243. Section 7.1 of the same chapter includes the following: “The greatest lurking danger for a user today is that many out-of-date and inferior methods remain in general use. Here are some traps to watch for: - Never use a generator principally based on a linear congruential generator (LCG) or a multiplicative linear congruential generator (MLCG). We say more about this below. - Never use a generator with a period less than ~ 2 64 ≈ 2 x 10 19 , or any generator whose period is undisclosed. - Never use a generator that warns against using its low-order bits as being completely random. That was good advice once, but it now indicates an obsolete algorithm (usually a LCG). - Never use the built-in generators in the C and C++ languages, especially rand and srand . These have no standard implementation and are often badly flawed. If all scientific papers whose results are in doubt because of one or more of the above traps were to disappear from library shelves, there would be a gap on each shelf about as big as your fist. You may also want to watch for indications that a generator is overengineered, and therefore wasteful of resources: - Avoid generators that take more than (say) two dozen arithmetic or logical operations to generate a 64-bit integer or double precision floating result. - Avoid using generators (over-)designed for serious cryptographic use. - Avoid using generators with period > 10 100 . You really will never need it, and, above some minimum bound, the period of a generator has little to do with its quality. Since we have told you what to avoid from the past, we should immediately follow with the received wisdom of the present: An acceptable random generator must combine at least two (ideally, unrelated) methods. The methods combined should evolve independently and share no state. The combination should be by simple operations that do not produce results less random than their operands.” 244. And then the authors give what they say is a reliable generator. 245. Not only does this deprecate LCGs, Optis submitted, but it says that an “acceptable” random number generator must combine at least two methods. 246. At the end of page 344, NRC says this: “Looking back, it seems clear that the field's long preoccupation with LCGs was somewhat misguided. There is no technological reason that the better, non-LCG, generators of the last decade could not have been discovered decades earlier, nor any reason that the impossible dream of an elegant "single algorithm" generator could not also have been abandoned much earlier (in favor of the more pragmatic patchwork in combined generators). As we will explain below, LCGs and MLCGs can still be useful, but only in carefully controlled situations, and with due attention to their manifest weaknesses.” 247. Optis submits that the last sentence only condones LCGs in the controlled situations referred to, and in combination with another method. 248. On the other hand, it was clear from Prof Lozano’s evidence, accepted by Ms Dwyer and also supported by NRC and Knuth (and Wikipedia for what it is worth) that LCGs were very well known, had a long history, and were fast and easy to understand and implement. 249. Ms Dwyer disagreed that any of NRC or Knuth or Wikipedia was CGK, but she did agree that if the skilled person wanted to use a RNG they would look it up and come across LCGs as one of the categories (and as I have said, she accepted Wikipedia as a jumping off point). She accepted that if the skilled person looked them up, they would find out: i) The basic formula; ii) The parameters; iii) The sensitivity of the LCG to the choice of parameters; iv) That LCGs were easy to implement and fast and that the theory behind them was easy to understand. 250. Drawing this together, the skilled person would appreciate from routine research that they would undertake if they considered that the Ericsson function should be replaced, that LCGs had much to commend them, and had been widely used for a long time. The skilled person would see Knuth as a reliable source of the teaching about how to implement LCGs that I have identified above in the section dealing with the teaching of Knuth. 251. The potentially very large “but” in Apple’s way lies in the comments in NRC that LCGs were actually poor, or even very poor random number generators, and should not be used on their own. Optis deployed this heavily. 252. Although initially very striking, I think the statements in NRC are of low relevance, at most, to the issue of obviousness in this case. I accept Prof Lozano’s evidence that what is under consideration in NRC is demanding situations where very long sequences of very random numbers are needed (“very random” in the sense that they pass extremely stringent tests intended to identify even the smallest signs of a pattern; an example was called “Diehard”). He was clear that sometimes sequences as long as 10 30 or 10 40 were needed, and that for cryptography sequences were needed and were produced that were “ longer than the [age] of the universe measured in seconds ”, but that that was “ way beyond what anyone at RAN1 would even think about. At RAN1 we have never seen sequences of more than a few thousand or maybe tens of thousands of repetition of period .”