back to article EU releases 2G GSM-reserved spectrum into wild

The EU has officially released the 900MHz spectrum formerly reserved for 2G GSM services, allowing other technologies into the space assuming that local regulators can sort out the historical mess. The Council of Ministers has approved the Commission's proposal to allow other technologies into the slices of 900MHz where 2G GSM …

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  1. Sean Aaron

    That would certainly help

    I've been with 3 for a few years now and the lack of signal penetration into structures by 3G signal even when I've got masts nearby is a real problem. I've actually considered moving to O2 just to be able to have a phone that could be run 2G rather than 3G so I can get better signal in my flat!

    Mobile is mature enough that hopefully we can avoid the non-interoperability of hardware that the US was saddled with during the time when Europe enjoyed the increased competition afforded the GSM interoperability.

    I say bring it on; if Vodaphone and O2 get some of their share taken away (they didn't pay for it in the first place, so they have no right to complain) and assigned to other carriers it can only benefit the consumer. I know I'll be more likely to stay with 3 if I can get a phone that does 900MHz (selling iPhones wouldn't hurt either).

  2. Andy Watt
    Stop

    Gah! Noise floor/cell size!!

    Hang on. 3G is spread spectrum, with a noise floor limitation. Greater coverage, bigger cells, more phones in one cell: noise floor issues!!! Not to mention worse bandwidth (possibly?) than 2.1GHz 3G!

    I still say EDGE is good enough, at least you get a timeslot to yourself!

    Penetration through walls is all very well, but won't that mean two phones in the same room shouting to be heard through the brickwork would keep throwing each other off the outside 900MHz (or 2.1ghz) cell?

    This simply doesn't stack up, does it?

  3. Anonymous Coward
    Anonymous Coward

    900MHz is a good thing for 3G

    @Andy, It's GSM that is noise floor limited, 3G is interference limited. A subtle but important difference. Okay so a 900MHz cell can be larger due to reduced attenuation. We have to trust the operators to dimension the networks such that the load in a cell is acceptable. Load doesn't come from area, it comes from subscribers and the services they choose to use. A 5MHz carrier at 900MHz has the same capacity as a 5MHz carrier at 2100MHz.

    EDGE timeslots are shared between users (TDMA).

    Two 900MHz 3G phones in a room will work better than two 2100MHz phones in a room. They will not interfere directly with each other as they transmit and receive on different frequencies. The base stations will receive a signal from both of them, each attenuated by the wall and the free space path loss. Sure there will be intracell interference, but no worse than is the case today at 2100MHz, 900MHz does not make the situation worse. The signal to interference ratio will be the same but the signal to noise ratio will be better.

    The problems come with the reduced gain of hanset antennas at 900MHz compared to 2100MHz... also, is the duplex spacing reduced which would lead to increased interference?

  4. Andy Watt

    @AC - ok, but...

    "Two 900MHz 3G phones in a room will work better than two 2100MHz phones in a room. They will not interfere directly with each other as they transmit and receive on different frequencies."

    Well, there is duplex spacing to consider, but they do both babble in the same 5MHz spaces at the same time - that's WCDMA, isn't it? Shared spectrum, they will interfere with each other, but the whole raison d'etre of WCDMA is extracting the original signal from the noise (raising it above the noise floor) by reverse application of the spreading code assigned to the mobile...

    Hence, my comments about noise floor - WCDMA has an acceptable noise floor in the cell - go above this, and you can't get sufficient SNR to get a mobile signal from the noise.

    Why is GSM noise floor limited? A timeslot exists on a frequency, and a mobile has exclusive (scheduled - right enough, the slots are shared thanks to MAC) access to TX on that timeslot at that time period within that frequency. EDGE specified new air interface encoding and GPRS coding schemes to give more bandwidth to a single slot.

    My question still stands: I still don't see how WCDMA at 900MHz is any better than 2100 - it's a license to make cells bigger, and bigger cells will (should! Cell breathing, remember) cover more area, therefore more devices will use one cell. Contention, spreading codes, etc -> less bandwidth for each device, and how do you manage the noise problem when someone on the edge of a densely populated 900MHz 3G cell starts ramping up their channel requests in their attempt to get a channel to make a move to the cell?

  5. Jón Frímann Jónsson
    Boffin

    Using 3G 900 in Iceland and Finland

    They are using 3G 900 in Finland and Iceland at the moment. I am Iceland, so I know. But Siminn has started to use 3G 900 few weeks back on remote areas (but they need use 3G in towns too in my opinion).

    But it is good that EU has opened the 3G on 900Mhz for all.

  6. This post has been deleted by its author

  7. c 1

    @andy watt - real world proves you wrong

    there are a number of commercial UMTS 850 networks that are providing great coverage and performance. UMTS 900 deployments should be almost identical. Down here in Oz we have a national UMTS 850 network (99.9% population coverage) that gives consistent real world data speeds (with the right device) of 6-10Mbps or even higher. Indoor coverage is fantastic. Voice calls are never a problem.

    With decent cell planning the simplistic potential problems you describe don't manifest to the end user. That is a fact.

  8. Anonymous Coward
    Anonymous Coward

    Noise and Interference

    @ Andy, you're muddling noise and interference, they are different things. Interference attenuates and noise doesn't.

    If you don't see why lower frequency means that the UMTS operators can use bigger cells you're missing some pretty fundamental understanding of how CDMA works. I also think you are exaggerating the impact of cell breathing, admission control maintains good margins preventing cell load getting high enough to significantly affect coverage.

  9. An nonymous Cowerd
    IT Angle

    silly question re 3G @ 900MHz

    will the current generation of smartphones and 3G business phones be able to use the 3G waveform at 900megs?, I presume that eg my Nokia E65 has the 3G radio hardwired to the 2GHz antenna and the 2G radio to the 900 antenna? I've only opened the phone to repair the screen myself, I never stripped the phone down to find the evolved antenna.

    Any comments on which terminal hardware is used in Iceland and Australia?

  10. Anonymous Coward
    Anonymous Coward

    3G @ 900

    Most current 3G handsets work at UMTS900 as well as UMTS2100. I beleive the whole Nokia range does, not sure about others.

  11. Anonymous Coward
    Coat

    Re: 3G @ 900

    Ok, thanks.

    I found that the Nokia website phone technical specification lists the "Operating Frequency"

    of their devices, my E65 isn't WCDMA 850/900MHz, whilst the newer E75 is.

    (in some areas!) quote from the E75 spec.

    Operating Frequency

    * Nokia E75-1 Quad-band EGSM 850/900/1800/1900, WCDMA 900/1900/2100 HSDPA

    * Nokia E75-2 Quad-band EGSM 850/900/1800/1900, WCDMA 850/1900/2100 HSDPA

    and the Nokia 6555 spec.

    Operating frequency

    * WCDMA 850/2100MHz (Europe, Middle East, Africa and Brazil)

    * GSM/EDGE 850/900/1800/1900MHz (Global)

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