Ekhaatvensters
Executive Member
Speed and latency are unrelated, especially when you're comparing two different access mediums.
The rest of this thread was discussing that too if you read. :/
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Speed and latency are unrelated, especially when you're comparing two different access mediums.
The rest of this thread was discussing that too if you read. :/
AirWolf
Honorary Master
If you followed V3g's explanation it is related. But only the speed of one link out of many is increased, so even though the difference in latency may not be hugely significant [yet] doesn't mean there is no improvement.
Pitbull
Verboten
Still to be proven.
It is not related. Period. If you have used the internet for more than just browsing and e-mail you would have noticed that. No matter how you try and say it is. You can speed it up as much as you want, there is just too many routes that needs to be traveled and there is various obstacles that influences the latency. Increasing the upload speed will not affect your latency to such an extent that you will notice it.
I can prove this to you by connecting on any service provider at different speeds. You will see a latency difference when moving from GSM to UMTS. But the different speeds on UMTS does little to nothing in relation to latency.
To have a good latency, you need a very strong and reliable routing system, you need very good BW and it also depends on the congestion. I can connect to the internet at 7.2mbps but that does not mean I will connect to a UK server at sub 100ms (Latency) You can increase the speed of your connection to as much as you want, you will never break the 100ms mark to the UK no matter what.
If you Had a latency of 200-300 ms without HSUPA you will have a latency of 200 - 300 ms latency with HSUPA. You can increase the bit rate to as much as you want. It means data is being pushed thru quicker, it doesn't mean that it gets to its destination and back at a higher rate...... get what I'm saying.
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AirWolf
Honorary Master
Pitbull
Verboten
If something goes faster how will that not decrease the time taken on the round trip?
No.
If you have info that needs to be processed on my machine aka Server, and my Server is a 386 Machine. Will you get it back quicker than you used to before ?
What I'm saying is, if you double the speed at what you upload or download... according to what you guys are saying, it will the 1/2 your latency. That is not true.
example:
GPRS - Latency = 800ms (GSM)
3G - Latency = 600 - 700ms (UMTS)
HSDPA - Latency = 500 - 600ms (UMTS)
see the difference. This is Just an example. I sucked the speeds and latency out of my thumb
But that will paint the picture I'm talking about. See the difference is huge between the speeds, does that make a real difference in the latency ? Now tomorrow I connect again.
GPRS - Latency = 900ms
3G - Latency = 700 - 800ms
HSDPA - Latency 600 - 700 ms
Now what happened ?
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AirWolf
Honorary Master
No because only a portion of the total route has an increase.
Pitbull
Verboten
Sorry you where to quick for me, see the examples, and pls tell me what happened.
Pitbull
Verboten
Ok let's put a little spanner in the works.
You live 100m from the nearest tower.
1000ms = 1 sec of Lag (Latency)
Your data travels to the tower in a fraction of a millisecond. And you receive it back at the same rate.
So in essence to what you are saying if I up my upload speed i will save about 200m distance of increase in latency for a distance of about 15000 km's one way (if not more). That would prob save me about 2ms (Yes I'm feeling generous)
You live 100m from the nearest tower.
1000ms = 1 sec of Lag (Latency)
Your data travels to the tower in a fraction of a millisecond. And you receive it back at the same rate.
So in essence to what you are saying if I up my upload speed i will save about 200m distance of increase in latency for a distance of about 15000 km's one way (if not more). That would prob save me about 2ms (Yes I'm feeling generous)
Pitbull
Verboten
Damn, it took me long to find it
Here you go
http://en.wikipedia.org/wiki/Throughput
and
http://en.wikipedia.org/wiki/Relationship_Between_Latency_and_Throughput
Here you go
http://en.wikipedia.org/wiki/Throughput
and
http://en.wikipedia.org/wiki/Relationship_Between_Latency_and_Throughput
Providing the service as part of the bigger bundles is a viable option and one the P&S guys do look at continuously.
How do you get the 'trailing MTN' bit? Last time I looked the VC-3.6 service was available on every tower around the country while forumites over in the MTN sub-forum were hard-pressed to find a few 3.6 towers and no 7.2 at all. Seemed (at launch time) the only place MTN 3.6 and 7.2 was available was in the Sunday paper ads.
Might be a bit better now but I still know of only 1 MTN-7.2 tower in Cape Town (Harrington st).
Yea I say Vodacom does seem to be trailing MTN Latency wise.
Download speeds and upload speeds with Vodacom are really impressive, but for online gaming its terrible. In WOW i get 1000 - 2000ms (with lots of disconnections from the game) with Vodacom and AOC I get around 600 - 700ms but very unstable too.
MTN on the other hand, offers me mediocre download speeds and terrible upload speeds, but the Latency is amazing, for WOW i get 300 - 400ms very stable at all times and AOC i get 200 - 300ms (late at night the connection to AOC actually drops to around 150ms).
By the way the Vodacom tower is much closer then MTN tower where I live and I use an aerial anyways.
This was not always the case with Vodacom though, they at a certain time they had really good latency, but that changed around September last year.
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lilDeath
Executive Member
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RoosTa
Expert Member
Speed <> Bandwidth
Speed <> Latency
Latency = Time
Speed = Distance/Time (remember that in school?)
In a perfect word, latency is calculated by using the good old "s = d/t" formula (simple math & science). However, in the real world, latency is also effected by bandwidth and priority (shaping).
Bandwidth is the amount that can travel down the pipe at the same time. The bigger the pipe then more data can pass through a point, at the same speed. If a bottle neck occurs, less data will be transmitted, but speed will remain the same.
Speed <> Latency
Latency = Time
Speed = Distance/Time (remember that in school?)
In a perfect word, latency is calculated by using the good old "s = d/t" formula (simple math & science). However, in the real world, latency is also effected by bandwidth and priority (shaping).
Bandwidth is the amount that can travel down the pipe at the same time. The bigger the pipe then more data can pass through a point, at the same speed. If a bottle neck occurs, less data will be transmitted, but speed will remain the same.
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A WoW Gamers Perspective
For those of us that utilise our monthly bandwidth for playing online games the most important aspect is reliable, low international latency.
I stay in Midrand (not far from Vodaworld and less than 200m from a Vodacom Tower) so signal strength is not an issue for me, I play WoW nearly every weeknight from around 19h00 till 01h00, using a Huawei E220 (firmware upgraded to connect at 7.2Mbps) USB Modem.
My latency between the EU Server and myself sits around the 700ms, on a good night. In the past several months however Vodacom's Network has been "spiking" alot and the latency is all over the place (latency sitting well over 2000ms) which is highly annoying for any online gamer! From 00h00 onwards my latency will often drop below 550ms.
What Pitbull and I want to know is does HSUPA offer a lower, stable international latency?
If the answer is "Yes" then please provide the results of your testing!
If the answer is "No" then please provide the results of your testing!
Seriously thou would Vodacom be prepared to improve on the service they offer by "tweaking" their systems to allow for a low, stable international latency for online gamers specifically?
After reading through this thread I realise 3G is a best effort service, results will vary from location to location and not only online gamers use Vodacom's Services so I suppose my question to Vodacom is like farting against thunder.
But for what I use the internet for I will move to which ever Service Provider will offer me the best experience!
Thanks
Magician
For those of us that utilise our monthly bandwidth for playing online games the most important aspect is reliable, low international latency.
I stay in Midrand (not far from Vodaworld and less than 200m from a Vodacom Tower) so signal strength is not an issue for me, I play WoW nearly every weeknight from around 19h00 till 01h00, using a Huawei E220 (firmware upgraded to connect at 7.2Mbps) USB Modem.
My latency between the EU Server and myself sits around the 700ms, on a good night. In the past several months however Vodacom's Network has been "spiking" alot and the latency is all over the place (latency sitting well over 2000ms) which is highly annoying for any online gamer! From 00h00 onwards my latency will often drop below 550ms.
What Pitbull and I want to know is does HSUPA offer a lower, stable international latency?
If the answer is "Yes" then please provide the results of your testing!
If the answer is "No" then please provide the results of your testing!
Seriously thou would Vodacom be prepared to improve on the service they offer by "tweaking" their systems to allow for a low, stable international latency for online gamers specifically?
After reading through this thread I realise 3G is a best effort service, results will vary from location to location and not only online gamers use Vodacom's Services so I suppose my question to Vodacom is like farting against thunder.
But for what I use the internet for I will move to which ever Service Provider will offer me the best experience!
Thanks
Magician
vodacom3g
Vodacom Representative
The HSDPA / HSUPA connection is just the few hundred meters from you to the base station.
From then on it's all fixed line (mostly Telkom), right to the server you play on.
Latency on wireless will always be higher than on copper or fiber. It's just how the technology works.
TheRoDent
Cool Ideas Rep
This is actually not entirely true. As a statement on it's own, it is true, however in context of a deployed HSDPA/HSUPA network latency
is affected more by many other factors.
The problem with latency wireless technologies such as 3G/HSxPA, WiMAX etc is due to the fact that it is a shared medium.
This means that base stations have to poll, or assign timeslots to each device that wants to "talk" on that frequency, as mutliple devices "talking" at the same time will cause a malformed packet to be received. Some technologies such as CDMA use coded (bitmapped) transmissions that allows more than one talker to communicate at the same time, however there is always some form of polling involved.
Devices further away from a base station, also have to use a different modulation just to be able to successfully transmit a frame, for example QPSK is used further away, and QAM when closer to the BTS. Using a different modulation helps the packet "make" it to the BTS, but uses more radio resources because the different modulation schemes all have different efficiencies.
Thus, latency on a wireless connection is more a factor of how many users are connected to that basestation, how far away they are on average from the basestation and what traffic they are doing, because they are sharing a common frequency medium.
In essence, more users, more traffic, and distance introduces more latency.
This is also one of the reasons why wireless technologies latencies "jitter" more than dedicated medium connections such as ADSL, Fibre or Ethernet.
A user on the edge of a cell, can also bugger it up for everyone due to the system having to give him more timeslots due to his less efficient modulation scheme. Many users on the edge of the cell, could make it untenable for everyone, even though the users close by have a good signal. This is why cell planning is important.
Of course, as Vodacom3G points out, an increase in the spectral efficiency (number of bits per Hertz) does mean that each user requires less time to receive or transmit the same amount of data than in a less spectrally efficient system, and hence the latency will decrease.
But overall, from a users perspective spectral efficiency has much less of an impact on latency than general cell conditions and load (number of users/traffic) has.
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TheRoDent
Cool Ideas Rep
Speed, in a shared medium is related to latency, as well as the number of users, and other factors discussed above.
In dedicated mediums, such as fibre and adsl however, your statement holds true in a sense, depending on what you refer to as "speed".
Speed could either be the "maximum allowed bitrate" allowed by your service provider, or the actual underlying speed/encoding capability of the transmission medium.
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vodacom3g
Vodacom Representative
Yup, a (connected) user out on the edge of the cell can play havoc with users closer to the tower who try and connect.
As can be seen from some of the points TheRoDent made above, high-speed wireless networks are massively complex and just the fact that they can compete with fixed line networks is amazing in itself.