karthic Posted August 2, 2006 CID Share Posted August 2, 2006 hi guys i have one question for many years in my mind left unanswered why the upload speed is not the same as download speed? the cable which is going to be used is the same for both upload and download but why is this very large variation in upload and download speeds????????? Quote Link to comment Share on other sites More sharing options...
amc11890 Posted August 2, 2006 CID Share Posted August 2, 2006 because "they" are cheap. costs more for them to give you a faster upload Quote Link to comment Share on other sites More sharing options...
dlewis23 Posted August 2, 2006 CID Share Posted August 2, 2006 because "they" are cheap. costs more for them to give you a faster upload thats a good way to put it... karthic the main reason is when they setup the standards for DSL and Cable they set it up for more download speed. So what they do is they take from the upload and give it to the download basically, Quote Link to comment Share on other sites More sharing options...
tommie gorman Posted August 2, 2006 CID Share Posted August 2, 2006 I would also venture to say, it is partially because most peope D/L. Websurfing and such. Upload is not usually as impressive. Just my thoughts. Quote Link to comment Share on other sites More sharing options...
dn0 Posted August 2, 2006 CID Share Posted August 2, 2006 Another reason: A Docsis modem, for example, is receiving its downstream (or the data you are downloading) from a high end and very costly CMTS in a climate controlled head end or hub site. This downstream signal is being delivered over the optical network using again some high end and pricey DFB transmitters (if not DFB, then a higher level) at $6,000 to $10,000 a piece. And lastly, the downstream carriers are generally in a much cleaner spectrum (~80MHz thru 750MHz). The upstream or the upload side is being transmitted from a $30 cable modem through the upstream spectrum (5-42MHz) which is by nature noisy and difficult to keep clean. This is due to the fact that the upstream is susceptible to all the interfering signals that can originate from every single home or business in a node, which then travels back upstream to a common point at the node and then on back to the head end. All funneling back to one point at the receiver in the CMTS. The upstream transmitters are generally a cheaper type of transmitter that is located in the field and are susceptible to temperature extremes and severe weather. The most common modulation profiles used in Docsis are: Downstream: 64 QAM = ~27Mbps 256 QAM= ~38Mbps Upstream: QPSK= ~5Mbps 16 QAM= ~10Mbps The reason behind the lower data rates on the upstream is due to the difficulty in delivering that quality signal from the cheap cable modem through the noisy plant and through the cheaper node transmitters back up to the CMTS at the head end/hub. As time goes on, the error correction hardware will improve and allow the cable companies to place higher level modulation schemes and also multiple channels on the upstream which in turn will allow for higher speeds. My brain hurts now - sorry for rambling..lol. Hope this info helps. I am sure that the reasoning holds pretty similar for DSL users, also. Quote Link to comment Share on other sites More sharing options...
tommie gorman Posted August 2, 2006 CID Share Posted August 2, 2006 So let me get this straight. FIOS is faster because they are working with all new installed equipment. Where cable is working with old equip. and doing the best they probably can. And still make a profit. Am I close??? Quote Link to comment Share on other sites More sharing options...
dn0 Posted August 2, 2006 CID Share Posted August 2, 2006 So let me get this straight. FIOS is faster because they are working with all new installed equipment. Where cable is working with old equip. and doing the best they probably can. And still make a profit. Am I close??? That is arguable, but not necessarily incorrect. I'm sure Fios is still using a cheaper transmitter at the customer side than they are using at the CO side. Probably the reason that their Upload speeds are lower than the Download speeds. This is only an assumption, though. Another reason for all ISPs to limit upload is the obvious - Why does the consumer need all that upload bandwidth - excuse. Some day that mind set will change, we here in the USA just need more competitors to offer synchronous speeds, therefore forcing most ISPs to follow suit. Quote Link to comment Share on other sites More sharing options...
porsche6714 Posted August 2, 2006 CID Share Posted August 2, 2006 Upload is nice for online gaming. Thats about the only thing i use it for besides upload some pics to the web. Quote Link to comment Share on other sites More sharing options...
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