Methods of Connecting to the InternetTUTORIAL INTRODUCTION: The following are 10 possible methods of internet connection for consumers that I'm aware of. Most hi speed internet connections are asymmetrical meaning that they intentionally throttle back the upload speed to about 1/3 to 1/7th or less of the download speed so customers won't be tempted to use it instead of an expensive T1 connection for server purposes. Kbps stands for kilo bits per second, not to be confused with KBps which is kilo bytes per second. There are 8 bits in a byte. Computers measure in bytes, but internet transmissions are measured in bits just so us poor consumers are confused :-) A typical JPG picture might be 60 KB (kilo bytes) & if you multiply that times 8, it would be 480 Kb (kilo bits), so a dial up modem that has a maximum speed of 56 kbps would take at least 8.57 seconds to download the picture (480 divided by 56 = 8.57) & in actual practice it would be more like 12 seconds. From my perspective, the current limitations & bottlenecks in the internet limit things like playing movies to about 400 Kbps for continuous reliable downloading, though most hi speed internet connections are capable of bursts much faster than that, the servers often can't sustain continuous delivery much faster than that right now. For that reason, as a very rough rule of thumb, I would consider any internet connection capable of download delivering 400 Kbps or faster as being high speed. All consumer internet connections seldom work at anywhere near their maximum rated speed because of server bottlenecks, latency delays, etc. DIAL UP: Maximum speed is 56 Kbps in both directions (upload or download)(called symmetrical) but typically you can't rely on a continuous stream any faster than about 2/3 rds that speed or about 38 Kbps (quite slow). It ties up the phone line so you can't use it for phone calls & too often drops the connection & isn't considered an always on connection unless you've paid for an extra phone line dedicated for this. DSL: Occasionally & more accurately referred to as ADSL (asymmetrical digital subscriber line). DSL piggybacks on analogue phone lines but sends a digital signal across the line which uses a different part of the unused spectrum. A filter is required at each phone jack so that the digital portion doesn't interfere with the analogue portion. You can use your phone at the same time as using the internet & the internet is an always on connection. DSL Internet speeds started out at 960 Kbps download (they usually round that up & refer to that as a 1000 Kbps or a 1K connection). Upload speeds are 120 Kbps (quite slow) to 320 Kbps depending on your service provider. Recently in some urban areas ISPs have started to offer speeds up to 3000 Kbps download & upload speeds of 800 Kbps at no additional charge. DSL is most suited to communities with high density because it requires a run of wire no more than 5 kilometres (3 miles) from a hub, so it often is not cost effective for the local phone company to install in rural areas (like cottage or farm country), although some telephone companies in Ontario such as Amtelecom are way ahead of Bell in this area (certain remote cottages on the western end of Lake Manitou on the Manitolin Island have DSL coverage). Ultra high speed DSL is also available, 4000 Kbps download & 800 Kbps upload. Some ISPs also offer a "lite" DSL package for not much more than the price of dial up, but twice the speed of dial up in both directions (128 Kbps). CABLE: Cable is usually not an option outside of cities because of the need to run wires underground. Typical cable internet speed can be up to 3000 Kbps download although the fastest burst speed I was ever able to get under ideal conditions with Rogers was 2500 Kbps, which is still amazingly fast. Upload speeds are typically throttled to about 384 Kbps. Express versions can be up to 5000 Kbps download & 800 Kbps upload. My limited experience is that cable is a more reliable, faster connection than DSL. Cable modems in theory can handle up to 10,000 Kbps (10 Mbps), but cable company servers don't have the server capacity to handle that speed, nor do they need to offer it from a competitive point of view right now, but internet via cable still has a lot more potential, whereas DSL does not. Some cable companies offer one or two "lite" cable internet packages that are 2-4 times dial-up speeds, either 128 Kbps download & 64 Kbps upload, or 256 Kbps download & 56 Kbps upload, for not much more than the price of dial up ($19.95 & $29.95 CDN). Cable internet customers who are not also cable TV customers are often charged a monthly surcharge of $5. - $10. Wi-Fi (Wireless Fidelity): This is the big internet
buzz word & growing very rapidly. Coffee shops, marinas, hotels,
airport lounges & other places that cater to mobile business
people wanting to high speed log on to the internet with their laptops,
are installing the base transmitter/receivers (transceivers) so
that business customers will visit their establishments. Wi-Fi usually
requires the ISP to invest quite a bit in transceivers using the
IEEE 802.11b spectrum & protocol. Potential up to about 11,000
kbps or 11Mbps in speed, but almost always throttled back by the
ISP (Verizon is maximum 1544 Kbps) so several users
can share the same transceiver. Another version of Wi-Fi can handle
up to 54,000 kbps (54 Mbps). I'm not convinced that Wi-Fi has a
good rate of return on investment for those installing transceivers,
but coffee chains like Starbucks, or restaurants like MacDonald's,
or marinas probably don't care because it brings many more customers
into their store. Transceivers usually only work within a maximum
of 400 meters (1300 feet) direct line of site & much less when
it has to go through lots of walls with metal in them. The further
you are away, the slower the connection speed. Practical range is
about 90 meters (300 feet) from the transceiver
using normal powered transmitters. Some marinas have more powerful
Wi-Fi transceivers that can handle up to 900 - 1500 meters (about
3000 - 5000 feet) but they also require the user to have a high
powered transceiver Wi-Fi on their computer (not as common). Wi-Fi
operates very similarly to the wireless router hub for networking
in your house, except that users can't usually network with each
others computers, only with the internet & it's slower. Intel
is currently building Wi-Fi technology into it's Centrino chips
& many laptops come equipped for Wi-Fi. Those that don't can
inexpensively buy a Wi-Fi transceiver that plugs in the credit card
size slot. The problem is if you travel around, you are sometimes
logging on to Wi-Fi systems that are owned & operated by various
ISPs, so you pay for an access charge & time on each system.
If you are considering Wi-Fi for computers that stay in one area,
then a simple monthly charge like an ISP uses would accommodate
easy accounting, although it is usually a higher cost than conventional
hi speed connections (some charge $39. U.S. per month). Wi-Fi is
usually considered an always on technology because at least 7 or
more end users can be sharing the same master transceiver &
still each be able to get up to 1544 Kbps. Because Wi-Fi requires
an infrastructure like cell sites only with far less range, I don't
think this is a technology with far reaching potential & it
doesn't piggyback on existing technology. Wi-Fi uses the unlicensed
radio spectrum of 2.4 GHz. Some links: WiMax: Also known as 802.16a. Worldwide
Interoperability
of Microwave
Access is what
WiMax stands for. WiMax is a lot like Wi-Fi, but
unlike Wi-Fi's typical 150-foot range, WiMax has a range of up to
30 miles, (but typically about one to three miles in a city and
up to 10 miles in rural areas), offering a way to bring the Internet
to entire communities without having to invest billions of dollars
to install phone or cable lines (last mile connectivity). WiMax
greatly improves non-line-of-sight performance, and it is the most
appropriate technology available when obstacles such as trees and
buildings are present. WiMax has adaptive modulation support, which
allows for trade-off of bandwidth for range to reach customers up
to 30 miles away. In a typical cell radius deployment of three to
ten kilometres, WiMAX Forum Certified™ systems can be expected
to deliver capacity of up to 40 Mbps per channel (sometimes 70 Mbps),
which is enough bandwidth for thousands of residences to use DSL
type speed connectivity. WiMax will use frequencies in the 2 GHz
to 11 GHz range, specifically stronger powered licensed frequencies
of 2.5 GHz and 3.5 GHz & some unlicensed frequencies (weaker
power) such as 5.8 GHz. Approved in January, 2003, 802.16a (WiMax)
provides wireless, last-mile broadband access to connect homes,
businesses and wireless LAN hot spots. Experimental WiMax is occurring
in 2005, with new models reaching the marketplace in 2006 &
full-scale deployment of WiMax is expected to begin in 2007. There
are two main flavours of WiMax; 802.16d, which will be aimed at
broadband fixed wireless use, and 802.16e, which offers mobility
but is further away from commercial launch than 802.16d. WiMax will
be to DSL and cable modems what cellular was to land-line phones,
a freeing of the tether of hardwiring so you can roam, especially
when the second stage known as 802.16e extension to 802.16a introduces
nomadic capabilities that let users connect while roaming outside
their home service areas. WiMax should also be a great advantage
to rural communities where cable & DSL wasn't available &
to developing nations so they don't need to go to the expense of
hardwired infrastructure. Additional reading http://www.intel.com/netcomms/technologies/wimax/ Cell phone: Verizon & other cell phone providers in the U.S.A. are piggybacking on their existing cell infrastructure to use cell phones as an internet connection so they can sell more minutes & larger packages. To introduce this to people, Verizon is currently offering a free internet connection (no email address & no web site, just a connection to the internet like you would get free at the library). All you have to do is have one of their current cell phones capable of this service & purchase a $50. cable that allows you to plug your cell phone into your computer (via the Ethernet connection). It's unlimited usage after 9pm & simply uses up your minutes if you phone during the day. They probably have a more expensive plan that can be used at any time of the day. Speed is not exactly high speed, but there might be the potential to increase it. Analogue is 14 Kbps & digital (where available) I think bursts up to 160 Kbps but I was able to sustain 64 Kbps, so it's faster than dial up & useable anywhere you can get cell coverage (which is almost anywhere in the U.S.A. for Verizon). The advantage of this is that it requires no additional infrastructure, piggybacking on existing cell site coverage & you can use it while you are moving. Disadvantage is that it probably doesn't have the bandwidth for truly high speed access. Also, I found that with Verizon having just introduced this service, they don't have the server technology down pat yet so the server hops were often 10 times slower latency than normal which is a bottleneck & causes time outs, but that is probably not related to the cell technology, it is simply a matter of improving their backbone connections to the internet. There is no reason I know of why Bell or Roger/ATT couldn't introduce this technology in Canada at a better level than Verizon has done, since they already have a cell site infrastructure & are established as internet service providers too. 3G, or third-generation wireless will help to increase internet speeds over cell phones. 1xEV Wide Area Wireless: "Wide Area Wireless"
is slower than Wi-Fi but using the newer 1xEV protocol
(Verizon Wireless and Sprint PCS) it is capable of 600 to
800 Kbps which is still what I call high speed. It piggybacks
on existing cell sites which means that you have a 12 mile (19 kilometre)
range rather than 150 - 300 feet (with Wi-Fi). It also hands over
the connection from one tower to the next when traveling so you
have seamless uninterrupted internet coverage while traveling just
like with a cell phone. It might take quite awhile to roll out 1xEV
Wide Area Wireless, but I think it has much more potential for the
long term than Wi-Fi. Single direction Geostationary Satellite TV: Some TV satellite companies already offer a high speed internet connection using the existing satellite TV infrastructure for downloading & a dial up phone connection for uploading. Personally I don't think this is an ideal solution because it ties up the phone line & because satellites for TV are all in geosynchronous orbit around the earth at the equator, which at my part of the world (London, Ontario, Canada) is 43 degrees latitude, which means the signal has to travel through the atmosphere on an extreme angle, hence more interruptions from weather & more atmosphere to attenuate the signal. There are also latency issues for internet data because of the great distances involved. The advantage is that it is available now from some satellite TV providers & piggybacks on existing infrastructure. Some satellite TV companies say they have plans to eventually upload via the customers TV satellite dish (see geostationary satellite below) so you don't need a phone line, but that would require an (expensive) transmitter on the customers dish, probably a larger dish, a completely clear line of site to the satellite & very exact aiming to transmit to the satellite 22,236 miles out in space. Bi-directional satellite transmission also introduces significant latency issues because of the distances involved. Bi-directional Geostationary Satellites: Also
known as geosynchronous. Satellites are positioned in a fixed spot
22,236 miles (35,786 km) above the earth (the Clark belt) at the
equator. This is the point where gravity is exactly offset by centrifugal
force & the satellite stays fixed (doesn't orbit the earth).
Because of the great distance & since radio waves travel at
about 186,000 miles per second, there is a fraction of a second
delay (240 milliseconds at equator & more towards the poles)
for one way direction & another 240 millisecond delay or more
if the signal is bi-directional, which can be annoying on duplex
phones & this delay causes significant latency for internet
transmission (about half a second to get signal to where it's going),
when expecting a reply such as when mouse clicking on a web site,
the return signal has to travel this path again which means about
a 1 second delay between a mouse click & getting the start of
a result when browsing. The great distance also means that personal
mobile earth transmitters either have to be very strong, or aimed
with a large dish at the satellite. A completely clear line of site
is required with absolutely no trees in the path, because the microwave
transmission to the satellite could harm birds in trees. This technology
was used in the video phones for news coverage during the 2003 Iraq
war. There are 4 newest version satellites already in place to cover
most areas on earth through the Inmarsat3 (International Maritime
Satellite). Satellite bandwidth time & equipment is still very
expensive, although this will come down significantly over the long
haul as America replaces it's shuttle fleet so that it's cheaper
to put satellites in orbit. Current data rate is 64 Kbps
bi-directional using version 3 satellites. In 2005 they will have
in place the Inmarsat I-4 satellite system for Broadband Global
Area Network (B-GAN) which supports mobile & data (internet)
up to 432 Kbps, however current default buffer size of TCP/IP hardware
only allows 64 Kbps with the latency of Geostationary Satellites,
so this high speed is not well suited to internet use, especially
for time sensitive applications such as online games, NetPhone,
NetMeeting, etc. Non-Geostationary orbiting (NGSO) satellite networks:
Orbits (17,000 MPH) around the earth once each 90 minutes at low
altitude, usually 200 - 500 miles (321 - 804 km). Low orbit requires
many more satellites (hundreds) than geostationary satellites because
the satellites are low (not far out in space) so more are needed
to cover a given area. Possible problems that could wreck a satellite
could be all the space junk found at these low altitudes. Advantage
is that weak portable phones on earth can transmit to low orbit
satellites much easier, with less power & smaller antennas because
they are closer & because they aren't transmitting through as
much atmosphere & weather (at least in non equator regions),
they transmit straight up vertically. Low earth orbit also eliminates
delay in full duplex talking & latency problems for internet
data. A consortium (Iridium Mobile Satellite Services) undertook
to put up enough non-geostationary satellites for satphone coverage
to cover the earth. The companies went bankrupt before they could
get enough satellites in place to cover the whole earth, but they
are back in business again (see link below). Low orbit satellites
in my opinion have absolutely enormous potential for satphone &
data (internet) in the long run because it completely eliminates
the need for last mile wiring or cell site infrastructure on earth,
which makes it inexpensive for developing nations to start using
satphones or the internet. One satellite can cover the same region
as hundreds of cell sites (NGSO has a 700 km circular footprint).
With enough satellites, coverage would be uniform (no area on earth
not covered) & it can be used for internet & phone coverage
which frees us all up to go anywhere on earth & still be able
to be reached on a satellite phone (satphone) or to access the internet
on our laptop or PDA. I predict that low earth orbit Satellite holds
out the best long term practicality for universal
mobile coverage & probably will be the main method of mobile
communication throughout the world in the future. By Doug Hembruff. |
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