Wednesday 26 October, 2016, 19:12 - Spectrum Management
Posted by Administrator
It seems that consultants RealWireless have been at it again. At what again, you ask? Back in May 2014, Wireless Waffle reported that a report, produced for Ofcom had been modified to seemingly correct a factor of 1000 error in the forecasts for future mobile data traffic thus fatally skewing their forecasts for the amount of spectrum needed for mobile services.Posted by Administrator
This time, in a new report for the European Commission entitled, 'Identification and quantification of key socio-economic data to support strategic planning for the
introduction of 5G in Europe' (admittedly led by Tech4i˛ but where you can bet your bottom dollar that RealWireless were the spectrum experts), the mathematical brainiacs have declared that the amount of radio spectrum required for the next generation of mobile service (5G) by 2025 will be between 19 and 76 GHz depending on the 'sharing scenario', meaning that if operators are prepared to get along nicely and co-operate to use the same spectrum, somewhat less will be needed (as if that is going to happen!)
The report specifically considered a number of scenarios and concluded that it is in the use of 5G on motorways where the demand for spectrum is highest. This is based on the notion that there are :
1000 vehicles along a 1km stretch of motorway, most of which (75%) are using high rate (4K/UHD) and pervasive video applications and devices operating simultaneously in vehicles. The usage in vehicles on a busy motorway within a Smart City with traffic building up due to an accident, is estimated to be 215 Mbps per vehicle as described in the transport ‘day in the life of’ story.
Er, firstly, it doesn't take 215 Mbps to deliver 4K/UHD video: Netflix purportedly manage to deliver 4K video at 18 Mbps, so what is the other 200 Mbps per vehicle for? Obviously that is the driver playing 'Interactive 4D Battle Death Wars XIV' which streams live data from 200 other players to create a 'fully-immersive real-time near-death experience'. Obviously the driver can do this because the car drives itself.
Of course the amount of spectrum needed to deliver this connectivity, even if it did prove necessary, could be reduced by increasing the number of base stations. One every 4 to 5 metres should do it.
These silly preductions, and it's not just RealWireless, because based on the latest ITU estimates, we will all be streaming 4K video 24 hours of every day by 2043, are designed for one purpose only: to allow the mobile industry, most notably the manufacturers of network infrastructure (such as Ericsson and Huawei) to convince the world that more spectrum is needed, so that they can flog a load more of new equipment.
Are the mobile operators themselves clamouring for new spectrum? There is little evidence to suggest that they are. The latest spectrum auction in the US has failed, so far, to raise enough money from the mobile operators to pay the broadcasters to budge over and make way for the 'big boys'. And there are several spectrum bands that have been available for mobile services for 10 years or more (notably the 2 GHz TDD bands, and the 3.4-3.6 GHz band) for which no widespread services have been launched.
It's hard to see how the estimated 76 GHz of spectrum could possibly be needed in 9 years time, and even less so, why operators would invest in spectrum and infrastructure to allow bored drivers to play 'Interactive 4D Battle Death Wars' whilst stuck in a traffic jam. Wireless Waffle predicts that the real amount of spectrum needed by 2025 will be at least 10 times less than this. So, the gauntlet has been thrown down, let's come back in 2026 and see who was right!
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Various media outlets reported that singer Kylie Minogue (and other famous television personalities) are using radio waves to get a facelift. At Wireless Waffle we like a good radio related story and if it involved Kylie then we are triply interested.
So what are the 'collagen waves' that the report claims are giving Ms Minogue her youthful look? It turns out that it is not strictly radio waves that are being used, but that very high frequency ultrasound is to blame. There are several articles online with titles such as:
So, effectively, the treatment causes damage to the various bits of the skin under the surface, presumably older bits, and the body then repairs the area, presumably with new bits. This is done by introducing:
Wireless Waffle decided to test the approach using similar equipment available in our test facilities using the following, scientifically accurate procedure:
It therefore seems very plausible that the reason Ms Minogue remains to tasty as she approaches her 50th birthday is due to the application of high power ultrasound radio-waves. Maybe others would like to replicate our experiment and report back on how tasty they were able to make their thighs.
So what are the 'collagen waves' that the report claims are giving Ms Minogue her youthful look? It turns out that it is not strictly radio waves that are being used, but that very high frequency ultrasound is to blame. There are several articles online with titles such as:
- Radio Waves for the treatment of Skin Laxity; or
- Facial Skin Rejuvenation with High Frequency Ultrasound
to induce thermal damage to thus stimulate neocollagenesis in deep layers of the skin and subcutaneous tissue
So, effectively, the treatment causes damage to the various bits of the skin under the surface, presumably older bits, and the body then repairs the area, presumably with new bits. This is done by introducing:
a selective and controlled rise in tissue temperature.
Wireless Waffle decided to test the approach using similar equipment available in our test facilities using the following, scientifically accurate procedure:
- First we took the only thing hanging around that needed an improvement in its 'skin laxity' this being a chicken thigh that was in the fridge destined for a nice casserole or being barbequed.
- As we did not have 3 MHz ultrasound equipment available, we opted instead for the 2.4 GHz waves induced by our microwave oven.
- It is also said that Ms Minogue uses Pond's cream to improve her skin tone. To replicate this, we coated the chicken thigh in a layer of mayonnaise.
- As the areas surrounding the face will absorb some of the radio signal, we placed the chicken thigh on some cold, pre-cooked pasta and a few carrots and a piece of broccoli to simulate the neck and shoulders.
- As the power levels used for the collagen wave treatment are claimed to be between 50 and 200 Watts, and as our microwave was 900 Watts, we set it to '10%' to simulate a 90 Watt collagen wave signal.
Before | After |
Information on broadcast radio stations that are actually on-air in various cities around the world is sometimes easy to get hold of, and sometimes very difficult. For many African countries, the situation is quite dynamic as stations come and go, and also many stations have no web presence (whether web-site or streaming) making verifying things very complex.
As occasional readers may be aware, the Wireless Waffle team travel to some pretty out-of-the-way places in pursuit of digging out the most important factlets regarding all matters related to radio spectrum. And with that in mind, we bring you a bandscan of the FM band in Lomé, the capital city of Togo in West Africa.
For a country where the average annual income is just US$650, there sure are a lot of radio stations on the air!
As occasional readers may be aware, the Wireless Waffle team travel to some pretty out-of-the-way places in pursuit of digging out the most important factlets regarding all matters related to radio spectrum. And with that in mind, we bring you a bandscan of the FM band in Lomé, the capital city of Togo in West Africa.
Frequency | Station | Notes | |
---|---|---|---|
89.9 | City FM | Stereo | |
91.5 | RFI 1 Afrique | Stereo. RDS: Radio France Internat | |
91.9 | Sport FM | Stereo | |
92.3 | Zephyr | Stereo | |
93.1 | Taxi FM | Stereo | |
93.5 | Kanal FM | Stereo | |
94.3 | Radio Zion | Stereo | |
95.5 | Nana FM | Stereo. RDS: Test 123 | |
96.1 | Victory FM | Aflao, Ghana | |
96.3 | Victoire FM | Stereo | |
97.1 | Radio Metropolys Lome | ||
97.5 | BBC World Service | Stereo | |
97.9 | Radio Maria Togo | ||
98.7 | Bonne Nouvelle | ||
99.5 | Radio Lome | Stereo | |
100.7 | Radio De L'Evangile | Stereo | |
101.1 | Radio Horizon | ||
101.5 | Radio Kara | Stereo | |
102.7 | KNTB | ||
103.1 | Radio Carre Jaune | ||
103.9 | Frequence 1 | ||
105.1 | Radio Ephphata La Voix Du Presbyterien | RDS: RADIO | EPHPHATA | LA VOIX | DU | PRESBYTE | RIEN | |
105.5 | Sinai | Stereo. RDS: FM 105.5 | |
106.3 | Providence | ||
Correct as of 30 June, 2016 |
Since the 1980s, extensive amounts of time and resources around the world have been focussed on the search for extra-terrestrial intelligence (SETI). One of the primary methods of doing so, is listening for radio transmissions from far away worlds. But how do you decide what frequencies to listen on?
The main frequency that SETIologists believe would be the primary real-estate for aliens wishing to make themselves known is around what is termed the 'water-hole' at frequencies close to 1.5 GHz. This frequency range includes the so-called hydrogen line (1420.4 MHz) and hydroxyl line (1666 MHz) which are frequencies that are generated by naturally occuring processes within atoms. The other advantage is that Earth's atmosphere, which comprises quite a large percentage of water, is relatively transparent at these frequencies making Earth based observations easier. The logic is that any intelligent life would be as aware of these lines in the spectrum as we are, and would figure that these are good places to transmit. Whether the transparency of the atmosphere at these frequencies on the planets they inhabit would also point them in the direction of the water-hole is a moot point.
Other frequencies that have been considered are twice the water-hole frequencies (after all, intelligent life would surely be able to multiply by 2 - assuming their number system used the same integers as we do), or 4.462 GHz which is the hydrogen line times pi (because circles are a universal phenomena, right?)
But could we actually receive a transmission on such a frequency? Let's do the link budget calculation...
But path loss is dependent on frequency, and so if a lower frequency was used, say 100 kHz instead of 1500 MHz, the path loss (from Alpha) drops from 368 dB to a more managable 284 dB (84 dB less). Unfortunately the gain of the receive dish also falls from 51 dB to a measly -33 dB (also 84 dB different). But instead of a dish, we could use a long-wire to receive the signals, at 1.5 km long, it would have a gain of 2 dBi, so overall we would gain 33 dB in our link budget calculation.
"A-ha", you say, "but the transmitting antenna would have a lower gain too, so nobody really wins. If I do the maths right, the required transmitter power is now 284+0+0-168 which is 116 dBm or 400 MegaWatts, which is a bit far fetched isn't it?" Maybe, but it's easier to generate 400 Megawatts at 100 kHz than it is at 1.5 GHz (or it is for humans anyway). In fact, this kind of power is generated every day on Earth by... lightning storms.
It may come as no surprise, therefore, that researchers at the University of St Andrews believe that signals that were received in 2009 from exoplanet HAT-P-11b might well have been caused by lightning storms on the distant planet. But what use is this, it doesn't represent extra-terrestrial intelligence, just extra-terrestrial weather (and we already know that even the other planets in our own solar system exhibit different weather characteristics).
The point, if there is one, is that if we could modulate lightening storms, or perhaps induce them in a way that allowed them to occur in a predictable fashion, we could make signals big enough to be transmitted across inter-stellar space. According to Climate Viewer:
But if lightning can be heard many light years away, perhaps these artificially induced lightning strikes are nothing to do with their stated objective but are actually to 'send messages extra-terrestrially'. Maybe the signals received from HAT-P-11b are not just random lightning storms and despite the Daily Mail claiming that these are not messages from space, perhaps they are an attempt at communication after all. After all, stranger things have been true!
The main frequency that SETIologists believe would be the primary real-estate for aliens wishing to make themselves known is around what is termed the 'water-hole' at frequencies close to 1.5 GHz. This frequency range includes the so-called hydrogen line (1420.4 MHz) and hydroxyl line (1666 MHz) which are frequencies that are generated by naturally occuring processes within atoms. The other advantage is that Earth's atmosphere, which comprises quite a large percentage of water, is relatively transparent at these frequencies making Earth based observations easier. The logic is that any intelligent life would be as aware of these lines in the spectrum as we are, and would figure that these are good places to transmit. Whether the transparency of the atmosphere at these frequencies on the planets they inhabit would also point them in the direction of the water-hole is a moot point.
Other frequencies that have been considered are twice the water-hole frequencies (after all, intelligent life would surely be able to multiply by 2 - assuming their number system used the same integers as we do), or 4.462 GHz which is the hydrogen line times pi (because circles are a universal phenomena, right?)
But could we actually receive a transmission on such a frequency? Let's do the link budget calculation...
- The path loss from our nearest star, Alpha Centauri, which is 4.37 light years (41,315,094,156,000 km) away at 1.5 GHz is 368 dB.
- If we use a BIG dish, say 30 metres in diameter, to receive the signal, it would have a gain of 51 dBi.
- Let's also assume that the aliens are transmitting using a similar sized dish (and they are pointing it directly at Earth).
- If the signal is very low bandwidth data (say 100 bits per second) we would need a receiver bandwidth of around 100 Hz, giving a noise floor for a cryogenically cooled receiver of -168 dBm.
- The necessary transmitter power to overcome the noise is therefore 368-51-51-168 or 98 dBm or 6.3 MegaWatts.
But path loss is dependent on frequency, and so if a lower frequency was used, say 100 kHz instead of 1500 MHz, the path loss (from Alpha) drops from 368 dB to a more managable 284 dB (84 dB less). Unfortunately the gain of the receive dish also falls from 51 dB to a measly -33 dB (also 84 dB different). But instead of a dish, we could use a long-wire to receive the signals, at 1.5 km long, it would have a gain of 2 dBi, so overall we would gain 33 dB in our link budget calculation.
"A-ha", you say, "but the transmitting antenna would have a lower gain too, so nobody really wins. If I do the maths right, the required transmitter power is now 284+0+0-168 which is 116 dBm or 400 MegaWatts, which is a bit far fetched isn't it?" Maybe, but it's easier to generate 400 Megawatts at 100 kHz than it is at 1.5 GHz (or it is for humans anyway). In fact, this kind of power is generated every day on Earth by... lightning storms.
It may come as no surprise, therefore, that researchers at the University of St Andrews believe that signals that were received in 2009 from exoplanet HAT-P-11b might well have been caused by lightning storms on the distant planet. But what use is this, it doesn't represent extra-terrestrial intelligence, just extra-terrestrial weather (and we already know that even the other planets in our own solar system exhibit different weather characteristics).
The point, if there is one, is that if we could modulate lightening storms, or perhaps induce them in a way that allowed them to occur in a predictable fashion, we could make signals big enough to be transmitted across inter-stellar space. According to Climate Viewer:
DARPA wants to trigger lightning to protect infrastructure, satellites, and use the artificially generated ELF waves to send messages worldwide. Lightning strikes are “triggered” at the University of Florida and University of Arizona, a network of sensors called the Holographic Array for Ionospheric Lightning (HAIL) collects info on these strikes, and HAARP has a large role in the whole process.
But if lightning can be heard many light years away, perhaps these artificially induced lightning strikes are nothing to do with their stated objective but are actually to 'send messages extra-terrestrially'. Maybe the signals received from HAT-P-11b are not just random lightning storms and despite the Daily Mail claiming that these are not messages from space, perhaps they are an attempt at communication after all. After all, stranger things have been true!