4g is not "as yet unknown". LTE is not 4g. 4g is specified for 100Mbps per user for users moving at relatively high speed and 1Gb/s per user for static users.

http://en.wikipedia.org/wiki/4G

"Present implementations of WiMAX and LTE are largely considered a stopgap solution that will offer a considerable boost while WiMAX 2 (based on the 802.16m spec) and LTE Advanced are finalized. Both technologies aim to reach the objectives traced by the ITU, but are still far from being implemented.[7]

The first set of 3GPP requirements on LTE Advanced was approved in June 2008.[11] LTE Advanced will be standardized in 2010 as part of the Release 10 of the 3GPP specification. LTE Advanced will be fully built on the existing LTE specification Release 10 and not be defined as a new specification series. A summary of the technologies that have been studied as the basis for LTE Advanced is included in a technical report.[12]

Current LTE and WiMAX implementations are considered pre-4G, as they don't fully comply with the planned requirements of 1 Gbit/s for stationary reception and 100 Mbit/s for mobile.

Confusion has been caused by some mobile carriers who have launched products advertised as 4G but which are actually current technologies, commonly referred to as '3.9G', which do not follow the ITU-R defined principles for 4G standards. A common argument for branding 3.9G systems as new-generation is that they use different frequency bands to 3G technologies; that they are based on a new radio-interface paradigm; and that the standards are not backwards compatible with 3G, whilst some of the standards are expected to be forwards compatible with "real" 4G technologies."

The point about competition is that it shows that the NBN is not a clearly better choice for users. Furthermore, I don't know of any "killer app" that will make it so, do you?

By the way, I wasn't in the sticks, I was at Salisbury in Brisbane. The premises were simply not serviced by cable and the ADSL service was only available from Telstra at the time I chose wireless. I did get ADSL on, but the performance was so poor that I discarded it. Telstra were basically uninterested in fixing their line.

Rstuart,

Again we are arguing at cross purposes.

Assuming your calculations are correct, there are several assumptions that are absurd:

1 All the houses in the cell are connected to wireless broad band
2 They are also all connected and on line simultaneously
3 They are all in the centre of the cell with the lowest LTE.
4 There are no other spectrum such as the 3GHz and 5GHz available

If assumptions 1 is the more likely 30%, and 2 is 50%, this already boosts the rate up to nearly 2Mb/s.

When assumption 4 fails and the other band widths are opened up, this increases 10 fold or more.

Finally, the mobile broadband is not going to cater for those that need the 1TB of download capacity at 100Mb/s, but the smaller users that make up a large portion of the user base for whom 2Mb/s with 15GB per month is more than adequate.

Even now for $30p.m. you can get mobile broadband and VoIP for little more than the existing Teltra phone connection.

@Shadow Minister: All the houses in the cell are connected to wireless broad band

Fair enough. Shall we settle whatever figure the NBN is relying on? I think it was 70% or so. That would make the above figure 900 kbit/sec.

@Shadow Minister: They are also all connected and on line simultaneously

Nope, I don't assume that, and its damned clear from what I wrote that I didn't. It's also clear you are barely skimming what I've written. That's just plain rude, Shadow.

The 40:1 contention ratio accounts for the connections. If you don't understand how, go back, click on the bloody links that define the term and find out how for pete's sake. 40:1 is high. Internode for example uses 20:1.

@Shadow Minister: They are all in the centre of the cell with the lowest LTE.

The centre of the cell has the highest speeds, not the lowest. I was being generous. I know it sounds absurd that someone in the middle of a flame war could still try to be fair to the other side and not seize on the worst case every time, but not everyone is like you Shadow. If I was being accurate I would have chosen average, which is the 70 Mbit/sec.

@Shadow Minister: There are no other spectrum such as the 3GHz and 5GHz available

Ahh yes. Wasn't that were we left off a few posts ago? You said there was a spare 600 MHz per carrier lying around somewhere, as opposed to the 67 MHz required to get the current figures. Assuming that's true, you went on to say would change my 600 kbit/sec to 6Gb/sec. Obviously not. It would give you 6 Mbit/sec, which is still under ADSL speeds. Note: 10 times the spectrum, and still under ADSL speeds!

That aside, no one in their right mind would use 5GHz. From http://ez-bridge.com/Learning_Center/learning_center.htm :

"5GHz ... requires very good line of site and long distance links can be degraded by rain and snow."

You can find a list of possible spectrum allocations here: http://www.teleca.com/Renderers/ShowMedia.ashx?id=2a8fb418-6c6d-49d5-a3b0-e22583610188 Nothing above 3.6GHz.

@Antiseptic: 1Gb/s per user for static users.

I am struggling to put it more clearly than has already been done. Try this http://www.qualcomm.com/documents/files/lte-advanced-heterogeneous-networks.pdf :

"Figure 1. Spectral Efficiency is approaching theoretical limits".

and just above that:

"Comparing the performance of 3G and its evolution to LTE, LTE does not offer anything unique to improve spectral efficiency, i.e. bps/Hz. LTE improves system performance by using wider bandwidths if the spectrum is available."

My earlier statement "We are already squeezing pretty hard, aren't we?" wasn't a joke. It was a statement of fact. The metaphorical sponge I mentioned above has been squeezed dry. We are never going to send more data over a given chunk of spectrum then I assumed.

So where is this 1Gb/s figure coming from? It assumes a large chunk of spectrum. The wikipedia article does actually say you need 67MHz for 1Gb/s, but that's a theoretical figure. It;s actually 80MHz. From http://www.qualcomm.com/documents/files/lte-advanced-key-technology-messages.pdf :

"Although most operators do not have access to 100MHz of spectrum, LTE Advanced can provide 1 Gbps peak data rates when leveraging 4x4 MIMO (and using 80MHz of spectrum)"

4x4 means a 16 element phased-array antenna. Remember me mentioning that?

Compare that 80MHz for a single cell to the current 50MHz chunk of spectrum allocated to our carriers now. The 50MHz has to be divided among adjacent cells. If we were to give 80MHz to each cell we would have to allocate the carrier 400MHz to allow for cell overlap. The one trick LTE-Advanced brings to the party is that 400 MHz of spectrum doesn't have to be continuous. It can aggregate 20 Mhz chunks of disparate spectrum.

If you are keen on understaning this the only other thing I can suggest is reading http://en.wikipedia.org/wiki/System_spectral_efficiency to gain insight into the two figures mentioned on your favourite 4G page, http://en.wikipedia.org/wiki/4G One figure is the LTE-Advanced *link* spectral efficiency of 15 bit/s/hz, and other is the LTE-Advanced *system* spectral efficiency of 3 bit/s/cell/hz. The 3 bit/s/cell/hz (it's really 2.66) is the figure you multiply the carriers spectrum allocation by to get the peak stationary data rate.

Rstuart,

You are trying to compare wireless completely replacing fixed line, which with today's technology cannot be done, and I have never tried to claim so. What I have said is that there will sufficient wireless consumers to render the estimated returns on the NBN invalid.

Wireless is by far the fastest growing broadband market, but is still less than 10% of the sole household connection market. So your estimate of 70% connected is wrong.

For the top end users, wireless cannot compete with fixed line, but for a large chunk of consumers, it can meet their needs completely. If you recall we discussed previously the various applications used compared with bandwidth required, and very little needed more than 1Mb/s. The average download pm is about 6Gb but the median is far lower, and the lowest 1/3 probably use less than 2Gb. For them the $100 pre paid annual connection knocks the NBN into a cocked hat.

In the cities the networks provide adequate coverage for the present demand, the different spectrum are available, but require upgrades to towers, and to the dongles used, and while the consumption does not require the upgrade yet, in 5 years, it will.