HSDPA Broadband questions (3 broadband)

mcguyver

Hi can anyone answere these,

Does HSDPA have a contention ratio? if there is loads connected to the same cell will it be slower, how can i fine out where the closest cell is to me.

What is 3's Upload speed?

Is there any restrictions in place?

thebman

I'd like to know about 3's coverage. Anyone know if they have coverage in all areas marked 3G on the website or how to find out where their coverage is?

watty

mcguyver wrote:

Hi can anyone answere these,

Does HSDPA have a contention ratio? if there is loads connected to the same cell will it be slower, how can i fine out where the closest cell is to me.

What is 3's Upload speed?

Is there any restrictions in place?

Contention is terrible on WiFi and 3G/GPRS.

With a perfect system and ten users you get 1/10th of the bandwidth. On WiFi you would get maybe 1/30th of bandwidth. On 3G/HSDPA not as bad, maybe 1/12th or 1/15th.

The 3Mbps-ish is total cell bandwidth. It HAS TO get slower, basic mathematics. Unless it is a 100% perfect signal and 100% perfect protocol the slowdown is always more (worse = smaller) than (Peak speed)/(Num active users). I think it only supports up to 25 users on a cell and then the 26th gets NOTHING bps. No connection.

Weaker signal also means slower.
Cell Breath means that as more users added in center of cell someone nearer cell edge @1Mbps or faster might suddenly have no signal.

On fixed wireless contention is controlled and generally would only be at advertised maximum contention if everyone was using BW to full amount at the same time. You can't decide how many mobile users will be in a cell. So fixed wireless is generally better than busy mobile cells.

Upload on all 3G/HSDPA is limited typically 70kbps is cell is not busy. A busy cell maybe 8 to 12kbps. Mousing & keyboard only needs average of about 0.04kbps. So sending email, uploads and VOIP can be a serious strain on it. Hence Vodaphone claim that VOIP is unreliable. A cell can only cope with maybe 3 or 4 VOIP clients, or even only one if G711 is used rather than a high compression codec.

cold_filter

watty wrote:

On 3G/HSDPA not as bad, maybe 1/12th or 1/15th.

Vodafones HSDPA is 1/12th still a lot better than 1/48!

watty

No it's not. It's however many people are in the cell. If they enforced 1/12th then the 13th person would not get connected.

Also the 1/48 on DSL or Fixed wireless could be for 500 users. On some fixed wireless systems you might be on a 1Mbps max package and the SECTOR bandwidth is 50Mbps = HSDPA cell band width of 1.8Mbps or 3.6Mbps. Actually strictly it means what ever the number of users the cable segment/ DSLAM for DSL or Wireless sector supports the Comreg rule is that a minimum of 1/48th of the Bandwidth that all users together have been sold must be provided. Since in real life the actual number of users a DSLAM, fixed wireless sector or cable segment could be 20 to 50 times what a mobile sector /cell supports, statistics work in your favour on fixed system and savagely against you on a Mobile system.

Which would you rather be? one of 12 people sharing 1.8Mbps (about 100k or less really) who are all actually using the cell or 1 of 500 people, many who are only potentially using the sector/cable/DSLAM, sharing 50Mbps or more? In the 2nd case youo will mostly get your 1Mbps due to the statistical nature of it.

But when a total usage is 12, the experience is bumpy. There's no direct comparison between Mobile Contention and Contention on Cable, DSL or Fixed Wireless. You aren't looking at the same kind of thing.

If I was a user trying to get a connection, I rather the Mobile cell supported up to 24 rather than up to 12. Though a limit of 12 is very possible.

thebman

So is this a lie then:

With 3's new 3DataModem, you have access to fast speeds of up to 3.6Mbps guarantee smooth Internet surfing and online video/audio streaming. This neat little external mini USB device provides an interface for easy connection to laptops and desktops etc

Given they can't guarentee anything since it depends on the number of people in a Cell and since its mobile broadband, they don't know how many users are in each cell at any given time.

I'm looking at getting this for my parents because they don't have broadband. For some reason I got a proper map, the last time I went to the site, I got a different map the last time I went there and they have HSDPA coverage in my parents area.

Is it slower, the further you are from masts? They don't need it for gaming but for browsing and mail with some large photo attachments.

watty

Below a certain signal level I think it gets slower.

Marketing varies between the optimistic and naive to downright lies.

Sponge Bob

brim4brim wrote:

So is this a lie then:

not quite, its marketing ****e but not quite a lie

Given they can't guarentee anything since it depends on the number of people in a Cell and since its mobile broadband, they don't know how many users are in each cell at any given time.

so they guarantee no minimum speed . no lie there

and IF you got 3.6mbits this is true ...at that speed of course and you are guaranteed nothing as you know.

"speeds of up to 3.6Mbps guarantee smooth Internet surfing"

very true ...no lie there.

I would be very sceptical if I was able to get 1bar at 3 miles from a mast today. I know exactly what will happen if there is any sort of decent takeup between now and christmas.

At 400m away , full bars , and a perfect line of sight to the quietest sector on my cell I may feel luckier

philstar

when im testing 3 for speed, using the program "myspeed pc" what should i choose for test type...HTTP or socket??