Posted 30 December 2012 - 12:42
You get what you pay for. The less you pay for more likely it is that your provider will attract other customers also looking to pay as little as possible.
When cost is the main driving force, this makes it more likely that the ISP are also looking to cut their own costs resulting in lesser quality product (eg: spend less to get inferior networking equipment, spend less to have less backhaul that connects all their customers to the internet, spend less on staff and get less knowledgeable employees in the pool).
Even if you have an ADSL connection, your connection between you and your ISP will be fast, but then the connection between your ISP and the internet can be very slow at peak times if they are a budget ISP because all the ISP's customers will be sharing the same internet connection which goes from your ISP to the internet (this is called Backhaul).
A good ISP would buy a fast enough connection between themselves and the internet to ensure that even at peak times, it's still going to be enough for everyone, even if it is still probably going to be shared.
I would look at reviews for ISPs in your area for your area to see which are the good ones.
Generally ADSL, particularly ADSL2, ADSL2+, VDSL2, Fibre, etc. or other fixed services are going to be faster, because this speed is mostly constant between you and the ISP regardless of other users, it's just a matter if the ISP can handle the speed from their end with THEIR internet suppliers. With Wireless solutions, as said above, it is completed shared with all the other users connecting to the same radio tower in your area, regardless of how great the backhaul is from the Tower to the internet there is still this bottleneck.
Wireless radios work on different "frequencies" so that the wireless signals from other wireless radios do not interfere with each other. There is a finite amount of frequencies available for use because wireless radios are so common, from Radio Stations, Walky Talkies, CB Radio, Cordless Phones, Wi-Fi internet, Mobile Phones, TV, Radio, Military uses, Police/Emergency services, it is endless. A continuous group of frequencies is called spectrum (eg: all frequencies between 850mhz & 890mhz could be one spectrum).
The spectrum is auctioned off by the government to the highest bidder, and if it is your Wireless ISP who won it, then they only have between 850mhz and 890mhz to support all the Wireless internet connections in your area at once. In this example, 40mhz of spectrum (890mhz - 850mhz = 40mhz) can only possibly support a certain amount of users at maximum speed.
If you have more users than the 40mhz can handle, there are going to be slow downs unless your Wireless ISP can get new spectrum, which is a very long and expensive process to get the winning bid from the next government auction, and these auctions don't happen very often.
This is why fixed connections will always win over wireless. With a fixed connection, if the cable is not fast enough, the ISP can just dig up the ground and put in another. There is practically no speed limit (just have to pay for more digging and more cables) With Wireless, it is not so easy to add spectrum because there isn't much available to use, and when there is, it is an expensive long process to get it. You can't just start using someone else's spectrum without asking, because it will cause interference to their signals, it is extremely illegal and most likely would be hunted down by the government for doing it (Wireless radios can easily be traced to where they are coming from, just keep going in the direction where the signal is getting stronger).