Did I press something... ?:-) But so glad I asked. A wonderful reply. The video presentation and the obscurantist documentation that avoided providing real clue to back the claims irritated me.
I await his next version with credible independent metrics showing a live deployment in a busy city block and as you suggest not limiting the porn on offer. Christian Gord Slater wrote: > > > On 9 December 2014 at 14:10, Christian de Larrinaga <[email protected] > <mailto:[email protected]>> wrote: > > Hi Gord, > > ? http://www.artemis.com/pcell > Be interested to learn if anybody has got under the veil of this one? > > > I haven't seen that before, but I can guess having skipped through the > the "tech" vid in a minute or less. What follows is a common rant, > tailored to the "wow technology!" being > pushed|sold|wavedabout|linked-to .... > > > Instead of quite a lot of radio station sites oriented in cells, which > works OK until capacity is reached in that service area, they will use > lots of little radio stations, effectively forming smaller and smaller > cells. Nowt new - some cells are tiny, like femtocells. Some users use > P2P methods if they want the same things that other do. Nowt new > BitTorrent or VHS copy sharing are examples. To share effectively means > proximity, awareness and similar needs. > > Every single radio station of any form that had capacity or throughput > issues has used a similar technique since day one. Not all had good > marketing. > > Reduce the range and you improve co-channel interference (as well as the > side effect of reduced adjacent channel interference due to lower EIRPs, > both wanted and spurious). As long as each new small, local site has not > hit maximum capacity, for the required users in that service area, > everything is sweet. > A soon as a limit is reached, you have to reduce the service areas, with > reduced powers (which doesn't always mean reduced performance as you > might think), by adding more cells. The process repeats until someone > has a good idea. Limit hit, add more sites or upgrade tech to faster or > wider or $something_normal. > > Every now and again, someone has a good idea. Some of these need > marketing, some gain traction own their own merits, some are obvious as > soon as you see it. Some are purely theoretical and may take decades and > several generations of kit to be practical. > > In the days of morse and trained telegraphists, a station could hit it's > capacity in various ways. Staffing limits (morse training takes time and > good fists take decades to become good), lack of telegraphy equipment > and links, power and cooling constraints (watercooled sub-megawatt > stations existed in many countries), paperwork/procedural > inefficiencies, weather and climatic problems. Originally, none of these > where limitations of the "ether" as the transmission medium was called. > Eventually, there were so many stations that more and more frequencies, > or groups of them, known as "bands", needed to be used, as well as some > form of planning to make sure that the could co-exist without saturating > the medium. Lower power, shorter range stations were introduced, in a > similar method to nano-cells. They were shorter range not really by > design, but by chance, unused bands that were less suitable to long > range working could be utilised for shorter range use at certain times > of the day. > > At this point in history, we have frequency division (different > frequencies and bands), time division (operators allowing other traffic > on a time-sharing basis), range-limiting (where long range working > wasn't needed), backhaul limitations (onward transmission by telegraph > cables), procedural optimisation (streamlining message handling), > beamforming (using one or more directional antennae and exploiting them > actively, often by human intervention). > At this point in the tale, we're looking at the late 1920's and early > 1930s. > > In the remaining 90 years, throughput speeds have increased, equipment > has become more portable, cheaper in relative terms for the end-user > (arguable), all-pervasive and an expected part of everyday life. > > The problem of the 20's and 30's are the same today. > User expectations, which should be high, are in effect destroyed by bad > experience of mobile communications especially in busy areas. Cells are > large due to lack of investment and forward thinking. Backhaul is a > problem, as it is everywhere, until you have enough. If "enough" > backhaul can't scale up when demand goes up, you hit the problems when > the limit is reached. > > The actual radio media (the "ether") hasn't changed, the same laws of > physics are the same as they were 100 years ago, and probably have > always been similar to what we see today (or think we see), we (RF > people as a subset of tech society) may understand them better, that's > all. The obvious solution to most of the perceived problems are to use > diverse backhaul (install femtocells on xDSL all over the place), or > massively diverse backhaul (use technologies like bittorrent or similar > P2P) to provide more and more sites (cells) to provide the service to > the users. > > Nearly 90 years ago the same thing happened:- > > More radio stations were installed where needed to provide capacity as > needed, not just fill in gaps in coverage > ..and.. > Radio ops would share the weather and traffic lists and even rebroadcast > it to stations further away or with less advanced equipment, using > diverse methods. > > > That makes 3 assumptions - customers had to be willing to pay, companies > wouldn't overspend or under-provide and that weather was wanted by many > people. > > he selling point of this pCell $product|concept seems to be based on the > assumption that everyone wants the same Netflix movie at roughly the > same time. It claims to be able to provide 100% capacity to every user. > As long as they want the same Netflix movie. > > I'm not convinced that the speaker knows the physics or understands the > No1 problem he's creating for the customer - if user 1 wants to watch > porn and user 2 doesn't, then user 3 had better have the porn that user > 2 wants or the 100% claim is bullshit. You can only have 100% once, not > twice, if the content is different, in a given spectrum and coverage > area. Yes, the coverage areas are small (probably near-field). Yes, it's > new to him. It's possibly new to the audience. There are many parallels > to what he|they have claimed to invent|find|do. > Hell, the POTS telephone system itself is a possible analogy back to the > days of dial-a-disc and speaking clock. Limited content in the case of > dial-a-disc or speaking clock. Shared information at the end of the link > (you set your watch by it and could tell people that asked you the time > thereafter). Backhaul and coverage was extended until almost every > building in the country was served by a local dissemination station that > provided the service. Humans provided the P2P bit at the end. > Near-field, local comms, were by acoustic dissemination between people > who wanted the information/message/content. Service area is limited by > the laws of physics (transmission lines, EMC issues, power). You can > optimise the exchanges to improve speed (STD). > > For datacomms over RF we have come so far as a society from those early > days that the users are far, far removed from the technology that they > can't understand the physics or identify the limiting factors in their > troubles. > It's an exciting technology in the same way that blue smarties were > exciting. They are still smarties and are fucking chocolate inside. > There are only so many in a box. If you want, you could cut them up and > move your mouth closer to eat them. You could pop one in your mouth and > share with your neighbour if they want one. Smarties can't be > duplicated. You cannot break the laws of physics, or smarties. > > Forgive me if I chuckle at the audience at the end. Either it's a polite > audience or he's completely baffled them. I give 10/10 to the heckler, > the "tech" not so much. > > The team are obviously having fun and I don't want to piss on that for > one minute, but it's hardly a breakthrough in historical terms as well > as communications technology terms. I wish them well. I feel sorry for > people who buy into that expecting to use it to solve a problem unless > it's a netflix problem AND everyone wants the same. > Enthusiasm for something like that is hard to exude when the only > TV-style media I watch are MST3K shows from the nineties. I doubt anyone > nearby me would benefit even if I did rebro them locally at low power. I > accept that groups of people tend to want to watch the same things, > sometimes at roughly the same times. They tend to group closely > together. That's a software opportunity for delivery efficiency, > certainly not an RF breakthrough. > > There is only one 100%, even using "means diverse" as we all it. You > cannot provide 101%, nor can nature, without some convenient > assumptions. I wish he'd found an unlimited number of universes we could > parallel up by using bonding, *that* would help. Actually, I wish he'd > found a better compression algorithm for Netflix movies. > > > PS: Sorry, due to ranting nature of this I haven't spell-checked it or > read for continuity. Several phone calls interrupted it so read between > the lines and paras to get the sentiment. > > -- > sent via Gmail web interface, so please excuse my gross neglect of > Netiquette -- Christian de Larrinaga FBCS, CITP, MCMA ------------------------- @ FirstHand ------------------------- +44 7989 386778 [email protected] -------------------------
