back to article 3G networks appeal for power boost

Ofcom is considering allowing UK's mobile operators to quadruple the power of their 3G transmissions, to improve coverage and maybe roast a few more brain cells. The request came from Vodafone, but when Ofcom consulted the other operators they all wanted in, so now the regulator has published a consultation (pdf) with plans to …

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  1. Mage Silver badge
    Boffin

    Read how cellular works

    It's really only on isolated sectors/isolated rural cells/very large cells that this is any use. In normal cell configuration the distance of the cell beyond the next cell limits the power otherwise the handset/modem in that cell would have poorer performance.

    For most situations this makes no difference.

    With more Smart phones, iPhones, iPads, iTablets, mobile Sling, 3 modems, then you need more smaller cells to increase capacity and power is not a problem. only money to pay for backhaul and bases. Current Data is subsidized by expensive voice calls.

    If the % of data use rises and cells thus have to be smaller to increase capacity, then data prices will quadruple.

    1. Dino Saur
      Stop

      Take your own advice ...

      I always love when people give 'expert advice'.

      1) You are right that in a capacity limited network extra power does bugger all good, due to all of the cells interfering with each other. But for 3G, this applies to around 10% of the networks, mostly in the big cities.

      Look at the stats. '3' have 12,000 sites to cover the UK. Everyone else has less than 7000. 3G coverage is patchy at best, so they are coverage limited. Half of the time (or more) you are actually making a call on a 2G network with a "3G" phone.

      More power means larger cells (potentially).

      [Actually cell size is determined by CPICH power, rather than max nominal PA power, but CPICH is usually 10% of the max nominal.]

      2) At capacity, a single CDMA cell is power limited. Each code is allocated a certain amount of power to reach the scheduled user, and when you have a full set of users, the power for each is a fraction of the max nominal power. Since achievable throughput is related to the signal level at the receiver, increasing the total power and hence the power per code/user increases the throughput per user and, thus, the throughput and capacity of the cell. This is particularly the case with HSPA when CPICH is maintained at the same absolute level so that the cell size is not increased when the power is increased.

      3) Capacity is only a problem in dense city areas. Operators are already using 2 or 3 channels in these areas, but the vast majority of 3G sites are only one channel. Operators can simply double capacity in most cells by adding a second channel without impacting the ICNIRP limits at all. They don't need to increase the power for capacity in these cases, so why would they waste money trying to change the rules? They wouldn't gain as much capacity and they'd still have to upgrade the basestation sites.

      Increasing the power is more about coverage (including indoors) and reducing the number of sites needed to have a decent network.

  2. Anonymous Coward
    Thumb Up

    Never noticed this before:

    "Read more: * Ofcom * 3g * Tinfoil Hats * Power"

    How have I never noticed that third tag before?

  3. Anonymous Coward
    Megaphone

    What I'd like to know....

    ....is how the operators think that increasing the downlink power is going to help them that much. You need a balanced system, so if Tx power goes up by 3-6dB then Rx sensitivity needs to go up by 3-6dB too. And that isn't easy because the receiver is already operating at very close to the theoretical thermal noise limit and it can't be made entirely noiseless.

    I'd be interested to see how the operators plan to make their link budgets balance with this change.

    1. Dino Saur

      And the answer is ...

      You don't need a balanced system for asymmetric traffic. Most internet traffic (including mobile) is downlink biased, so you need more downlink capacity than uplink. Same as your DSL connection.

      Of course, as people upload more and more content, this will stop being true, but we are a long way from that.

      More basestation power means more downlink capacity (& coverage), as long as you are not limited by interference.

      Stop thinking of symmetrical services like voice or video calls and it'll all make sense.

  4. Ian 62
    Flame

    Marketing spin

    400% coverage increase!

    4 x the signal quality

    etc

    etc

    Wait for the cynical marketing to appear once its switched over to 11.

    1. Dino Saur
      Boffin

      Not quite ...

      6 dB is roughly four times the power, but you don't get the coverage. In free space, signal level decreases at 20 dB per decade of distance, so an extra 6dB would give you twice the distance and four times the area.

      If you Google for path loss models, you'll find that free space does not apply to mobile systems, since they are close to the ground amongst the clutter. Typical planning rules use values between 30 and 45 dB per decade. At 30 dB per, that's 2.5 times the coverage and at 40 dB per it's twice the coverage. Still, halving the number of required basestation sites is a nice saving for the operators.

      Regarding 'signal quality', 6 dB would give you a fair increase in throughput if you are near the cell limit, so would do nicely for improved indoor coverage (e.g. at home where most people seem to browse for pr0n with their dongles active).

      By the way, the limit is actually a **maximum**, so most transmitters operate at a lower nominal power with some margin to avoid breaching the limit. And, as the article notes, the limit was all about avoiding interference rather than protecting the tin-foil hat brigade.

  5. Gary F

    Nooo! My brain is friend enough thank you

    How can I object to this? The long term effects on people are still unproven. Can't they use something less harmful like sub-space or something?

    1. Mike Hanna

      Perhaps...

      ...they could use cups-and-string instead?

      The very vast majority of base stations radiate around 5% of the ICNIRP limits in place. Would this value need to be logarithmatically messed up or can we assume that with the base stations turned up to 11 that they will move up to 20% of the ICNIRP limits? Still well within the limits in place

      However, been able to pick up a stronger signal from a base station and getting more bars filled in on your phone does not mean that you can push more data, which should be the operators main effort...

    2. Piggy and Tazzy

      Mine too

      My brain is my friend too.

  6. Anonymous Coward
    Paris Hilton

    no doubt...

    a few incursions into a 3G operator or 2's security perimeters will occur in the next few months and a load of laptops containing sensitive data about how they plan to bribe the UK.gov into ignoring the WHO upper emissions limits again, will go walkies.

    (no doubt the prince of darkness is looking forward to getting his EFI suit ((in black obviously) though x-green Cross code man will no doubt be unhappy he is being sidelined by some dandy impersonator, and no doubt nicking all his gigs, hob-nobbing with the rich and famous)

    with DAB-HD2 having its abysmaly recieved signal being upped in output levels and the 3g brigade trying to upp the absurd limits, do we stand a chance to get issued with EFI/RFI proof suits so we can go outside without boiling from the inside out in deepest midwinter ????

    the Emmisions safety reports are STILL being suppressed (in sections) by the DTi and £g operators, the rest of the EU is looking to wind the power levels down

    (except Romania, which is about to start cooking large sections of thier own population and Ukraine's with the bushy white elephant missile sheild).

    Sorry but >>> ) <<< is more likely to be better at shielding the Romanians against missiles or balista's.

    even my pet cat is getting seizures and muscle spasms from the ridiculously high emissions levels of RFI from the local 3G towers and 3G/GPRS/Satnav systems fitted to the local post office vans that are hammering past my front door all hours of day and night....

    and when some plonkers in blue go past with their Tetra radios going at full belt, gahhhh........

    were not even immune from the taxis, my hi-fi system fizzes and clicks when they pick up or drop off fairs near my place.

    Paris... cos even her poor pussy gets abused all hours of the day and night by rough ugly blokes who don't care...

    1. Anonymous Coward
      WTF?

      You know they have medication for that

      Perhaps its best you posted as AC...otherwise some lovely men and women in white coats would be bringing you to a nice padded room by now. Ever consider taking the cat to the vet to have its epilepsy treated? Let me guess....its not epilepsy its DA EVEL RFI *rolls eyes*

      They have proven time and time and time again, none of you RF sensitives can tell if the RF system is on or off, some will even claim its on when the item in question is an empty plastic shell, yet when they see the evil cell phone "my head my head my head!!".....bollocks is what I say to that.

      You do realise your microwave oven likely kicks out way more energy?

      oh and your electrical wiring will do the same, 240volts wrapped round the house like a giant aerial

  7. Anonymous Coward
    Dead Vulture

    the ICINIRP are only qualified...

    to make the tea, all-be it in a microwave oven.

    those guys are not micro-biologists, they have not a clue what PMR does to the guts of a bio-logical cell. you start talking cells to them and all they can relate to is batterys and how many base stations you can fill a powerpoint/excel grid up with.

    they, NSA, all the Telecoms and Mandy and co are suppressing the data that prooves that living near or using a handheld device is gonna cause some serious molecular damage and probably end up killing you, (especially if your using one in pakistan/yeman/afganistan or any other abnormally hot region) as there is inadequate screening for or control of cancer groups (almost anywhere)

    though the yanks are working tirelessly to erradicate the cancerous spread of some expanding groups in those countrys...

    and the first to go here will be all the numpty crack-berry adicts who cant stop twitering and doing email whilst doing 80+ zigzagging between ASR camera lanes down the motorway in thier Toyota's and Lexus's..... (oh-shi! my brakes are gone... i cant stop... help!)

    (one less twit and the average level of IQ for worlds population just rose a point)

  8. Anonymous Coward
    Anonymous Coward

    We really need lower 3G frequencies

    Mobile networks would really begin to perform for customers if O2 and Vodafone released some of their 2G spectum for ALL of the mobile operators to apply 3G coverage in the 900 band. We're not talking blanket UK coverage here just places where the networks dont even provide basic coverage yet.

    Vodafone and O2 have shown total arrogance in refusing to budge thus nothings going to change in the near future.

    OFCOM and the Government are now needed to force them to release the spectrum perhaps? Unless we are happy to continue settling for the crap coverage they currently brag about.

  9. Badbob
    Coat

    'bout time too...

    I am based in the middle of nowhere (in fact, that assumes nowhere is a place with a beginning, middle and end).

    I work in Fault Response for a large railway infrastructure owner, and often I am told to wait at a critical location for a report of a failure. This often results in long hours spent in a Transit van in a motorway service area waiting to hear which part of the railway network I need to dash to. Therefore I have a laptop and a 3G modem to hold off cabin fever. Coverage is patchy at best though, even on the motorway network. So an increase in coverage area and signal would be appreciated so i can load the network with more iPlayer downloads and avoid having to go do work.

    Mine is the hi-viz orange one with the multimeter in one pocket and good book in the other.

  10. Joe 34

    Where are these figures coming from???

    Has anyone worked out that 68dBm is about 6.3 kilowatts? A typical Nokia WCDA module produces around 20 watts, more like 43dBm.

    1. Dino Saur
      Boffin

      It's a little thing called EIRP ...

      That's 43 dBm **nominal** at the top of the basestation cabinet. Take off cable loss than add 18 dB of antenna gain gets you to around 60 dBm effective isotropic radiated power (EIRP). Antennas focus the power in one direction and that looks like a higher power radiated from a point source.

      Then allow 2 to 3 dB for PAR, production tolerance and temperature variation, then you could bust the current limit.

      From 40W, you get about 63 dBm EIRP, or higher if you increase the antenna gain or reduce the cable loss. Some people have been known to talk 60W per channel PAs.

  11. Anonymous Coward
    WTF?

    +68dBm = 6.3 kilowatts

    Ah, that's a lot. I'm not a member of the tinfoil hat crowd, but at that power level, I would not want to live in the close proximity

    1. David Hicklin Bronze badge

      Re: +68dBm = 6.3 kilowatts → #

      Go and live near a TV mast then - they put out up to 1 Megawatt

  12. Anonymous Coward
    Thumb Down

    "...TV mast..."

    I wouldn't live near a 1 megawatt TV mast either. But 3G masts are *far* more common.

  13. Mage Silver badge

    Rural Cells

    Data devices rather than Voice usage means they need x 100 times capacity for same number of users or it is rubbish. Compare usage patterns and 3G voice codec vs youTube video datarate.

    It is rubbish in many areas in Ireland due to capacity. Other areas the coverage is non-existent and needs more cells, not more power.

    http://www.boards.ie/vbulletin/showthread.php?t=2055115306

    http://www.boards.ie/vbulletin/forumdisplay.php?f=1147

    More power will help, but only on lightly used isolated cells. What they really need is more Cells.

    And any protocol other than Brain dead CDMA which should never have been the underlying 3G Air interface. Politics.

    http://www.radioway.info/comparewireless/img3.html

    http://www.techtir.ie/forums/showthread.php?t=1832

    Fixed Wireless Broadband can easily make use of more power to double data Rate at same range, because due to exclusively using chimney/outdoor directional aerials the "intercell" interference issue is very very much less. Typically allowing x16 performance in the same spectrum.

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