Broadband Internet access
, often shortened to "broadband Internet
or just "Broadband
", is a high data-transmission rate internet
connection. DSL and cable modem, both popular consumer broadband technologies,
are typically capable of transmitting 256 kilobits per second or more, starting
at approximately four times the speed of a modem using a standard digital
Broadband Internet access became a rapidly developing market in many areas in
the early 2000s; one study found that broadband Internet usage in the United
States grew from 6% in June 2000 to over 30% in 2003.
Modern consumer broadband implementations, up to 30 Mbit/s, are several
hundred times faster than those available at the time of the popularization of
the Internet (such as ISDN and 56 kbit/s) while costing less than ISDN and
sometimes no more than 56 kbit/s; though performance and costs vary widely
Broadband is often called high-speed Internet, because it usually has
a high rate of data. In general, any connection to the customer of 256 kbit/s
(0.256 Mbit/s) or more is considered broadband Internet. The International
Telecommunication Union Standardization Sector (ITU-T) recommendation I.113 has
defined broadband as a transmission capacity that is faster than primary rate
ISDN, at 1.5 to 2 Mbit/s. The FCC definition of broadband is 200 kbit/s (0.2
Mbit/s) in one direction, and advanced broadband is at least 200 kbit/s in both
directions. The OECD has defined broadband as 256 kbit/s in at least one
direction and this bit rate is the most common baseline that is marketed as
"broadband" around the world. There is no specific bitrate defined by the
industry, however, and "broadband" can mean lower-bitrate transmission methods.
Some Internet Service Providers (ISPs) use this to their advantage in marketing
lower-bitrate connections as broadband.
In practice, the advertised bandwidth is not always reliably available to the
customer; ISPs often allow a greater number of subscribers than their
practice, the advertised bandwidth is not always reliably available
to the customer; ISPs often allow a greater number of subscribers
than their backbone connection can handle, under the assumption that
most users will not be using their full connection capacity very
connection can handle, under the assumption that most users will not be using
their full connection capacity very frequently. This aggregation strategy works
more often than not, so users can typically burst to their full bandwidth most
of the time; however, peer-to-peer file sharing systems, often requiring
extended durations of high bandwidth, stress these assumptions, and can cause
major problems for ISPs who have excessively overbooked their capacity. For more
on this topic, see traffic shaping. As take-up for these introductory products
increases, telcos are starting to offer higher bit rate services. For existing
connections, this most of the time simply involves reconfiguring the existing
equipment at each end of the connection.
As the bandwidth delivered to end-users increases, the market expects that
video on demand services streamed over the Internet will become more popular,
though at the present time such services generally require specialised networks.
The data rates on most broadband services still do not suffice to provide good
quality video, as MPEG-2 quality video requires about 6 Mbit/s for good results.
Adequate video for some purposes becomes possible at lower data rates, with
rates of 768 kbit/s and 384 kbit/s used for some video conferencing
applications. The MPEG-4 format delivers high-quality video at 2 Mbit/s, at the
high end of cable modem and ADSL performance.
Increased bandwidth has already made an impact on newsgroups: postings to
groups such as alt.binaries.* have grown from JPEG files to entire CD and DVD
images. According to NTL, the level of traffic on their network increased from a
daily inbound news feed of 150 gigabytes of data per day and 1 terabyte of data
out each day in 2001 to 500 gigabytes of data inbound and over 4 terabytes out
each day in 2002.
The standard technology in most areas is DSL, followed by cable modem. Newer
technologies for twisted pair phone lines such as VDSL and pushing optical fibre
connections closer to the subscriber in both telephone and cable plants are
opening up the possibility of higher performance for streaming data, such as
audio and video streams. There are now many streaming audio services, and
several streaming video services. In a few of the many areas not served by cable
or ADSL, community organizations have begun to install Wi-Fi networks.
ISDN is an older telephone data service that can operate at speeds of up to
128 kbit/s. It is therefore not really considered a true form of broadband, but
it does have the advantage that it can share an existing phone line, and it has
no distance limitations like DSL. When a phone call occurs, some of the
bandwidth is allocated to the call, reducing the connection speed. When the call
ends, the connection increases speed again. ISDN is a relatively low-cost option
for rural users with otherwise terrible dialup access speeds, but it is starting
to be phased out and is no longer available in some areas.
One of the great challenges of broadband is to provide service to potential
customers in areas of low population density, such as to farmers and ranchers.
In cities where the population density is high, it is easy for a service
provider to recover equipment costs, but each rural customer may require
thousands of dollars of equipment to get connected. A similar problem existed a
century ago when electrical power was invented. Cities were the first to receive
electric lighting, as early as 1880, while in the United States some remote
rural areas were still not electrified until the 1940's, and even then only with
the help of federally-funded programs like the Tennessee Valley Authority (TVA).
Several rural broadband solutions exist, though each has its own pitfalls and
limitations. Some choices are better than others, but depend on how proactive
the local phone company is about upgrading their rural technology.
|A DSL filter is an analog low-pass filter
installed between analog devices (such as telephones or analog
modems) and a POTS telephone line, in order to prevent interference
between such devices and a DSL service operating on the same line.
Without DSL filters, signals or echoes from analog devices at the
top of their frequency range can result in reduced performance and
connection problems with DSL service, while those from the DSL
service at the bottom of its range can result in line noise and
other issues for analog devices.
installation for an existing home involves installing DSL filters on
every telephone, fax machine, voiceband modem, and other voiceband
device in the home, leaving the DSL modem as the only unfiltered
device. For wall mounted phones, the filter is in the form of a
plate which hangs on the standard wall mount, and upon which the
phone hangs in turn.
In cases where it is possible to run new cables,
it can be advantageous to split the telephone line after it enters
the home, installing a single DSL filter on one leg and running it
to every jack in the home where an analog device will be in use, and
dedicating the other (unfiltered) leg to the DSL modem. Some
devices, such as monitored alarms and Telephone Devices for the
Deaf, mainly certain older models using an acoustic coupler, may be
hardwired and may not easily accept a DSL filter. Some of these
devices can be successfully filtered with a DSL filter or splitter,
especially if the hardwired connection is converted into a jacked
This employs a satellite in geostationary orbit to relay data from the
satellite company to each customer. Satellite Internet is usually among the most
expensive ways of gaining broadband Internet access, but in rural areas it is
often the only viable option. However costs have been coming down in recent
times to the point that it is becoming more competitive with other high speed
Satellite Internet also has a high latency problem caused by the signal
having to travel 35,000 km (22,000 miles) out into space to the satellite and
back to Earth again. The signal delay can be as much as 500 milliseconds to 900
milliseconds, which makes this service unsuitable for applications requiring
real-time user input such as certain multiplayer Internet games and first-person
shooters played over the connection. Despite this, it is still possible for many
games to still be played, but the scope is limited to real-time strategy or turn
based games. The functionality of live interactive access to a distant computer
can also be subject to the problems caused by high latency. These problems are
more than tolerable for just basic email access and web browsing and in most
cases barely noticeable.
There is no simple way to get around this problem. The delay is primarily due
to the speed of light being only 300,000 km/second (186,000 miles per second).
Even if all other signalling delays could be eliminated it still takes the
electromagnetic wave 233 milliseconds to travel from ground to the satellite and
back to the ground, a total of 70,000 km (44,000 miles) to travel from you to
the satellite company.
Since the satellite is being used for two-way communications, the total
distance increases to 140,000 km (88,000 miles), which takes a radio wave 466 ms
to travel. Factoring in normal delays from other network sources gives a typical
connection latency of 500-700 ms. This is far worse latency than even most
dialup modem users experience, at typically only 150-200 ms total latency.
Most satellite internet providers also have a FAP (Fair Access Policy).
Perhaps one of the largest cons against satellite internet, these FAPs usually
throttle a user's throughput to dial-up speeds after a certain "invisible wall"
is hit (usually around 200MB a day). This FAP usually lasts for 24 hours after
the wall is hit, and a user's throughput is restored to whatever tier they paid
for. This makes bandwidth-intensive activities nearly impossible to complete in
a reasonable amount of time (examples include P2P and newsgroup binary
Netbooks from Amazon.co.uk
Large Range Of NetBooks available. Small, light and inexpensive laptop computers suited for general computing and accessing web-based applications
This allows a service provider to set up DSL hardware out in the country in a
weatherproof enclosure. However, setup costs can be quite high since the service
provider may need to install fiberoptic cable to the remote location, using
horizontal boring equipment at a cost of US$360/metre (US$600,000 per mile). Also, the remote site has the same distance
limits as the metropolitan service, and can only serve an island of customers
along the trunk line within a radius of about 2 km (7000 ft).
Remote DSL access is becoming a sore point for many rural customers, as the
technology has been available for some time now and phone companies keep
promoting its availability, but at the same time the phone companies keep
dragging their feet and are not doing anything to install the remote services.
In the United States, this is particularly a problem with the very large
multistate conglomerates that serve mostly rural areas
This is a very new technology which allow DSL to travel longer distances to
remote customers. One version of the repeater is installed at approximately 3 km
(10,000 ft) intervals along the trunk line, and strengthens and cleans up the
DSL signal so it can travel another 3 km (10,000 ft).
This is a new service still in its infancy that may eventually permit
broadband Internet data to travel down standard high-voltage power lines.
However, the system has a number of complex issues, the primary one being that
power lines are inherently a very noisy environment. Every time a device turns
on or off, it introduces a pop or click into the line. Energy-saving devices
often introduce noisy harmonics into the line. The system must be designed to
deal with these natural signalling disruptions and work around them.
Broadband over power lines (BPL), also known as Power line communication, has
developed faster in Europe than in the US due to a historical difference in
power system design philosophies. Nearly all large power grids transmit power at
high voltages in order to reduce transmission losses, then near the customer use
step-down transformers to reduce the voltage. Since BPL signals cannot readily
pass through transformers, repeaters must be attached to the transformers. In
the US, it is common for a small transformer hung from a utility pole to service
a single house. In Europe, it is more common for a somewhat larger transformer
to service 10 or 100 houses. For delivering power to customers, this difference
in design makes little difference, but it means delivering BPL over the power
grid of a typical US city will require an order of magnitude more repeaters than
would be required in a comparable European city.
The second major issue is signal strength and operating frequency. The system
is expected to use frequencies in the 10 to 30 MHz range, which has been used
for decades by licensed amateur radio operators, as well as international
shortwave broadcasters and a variety of communications systems (military,
aeronautical, etc.). Power lines are unshielded and will act as transmitters for
the signals they carry, and have the potential to completely wipe out the
usefulness of the 10 to 30 MHz range for shortwave communications purposes.
This typically employs the current low-cost 802.11 Wi-Fi radio systems to
link up remote locations over great distances, but can use other higher-power
radio communications systems as well.
Traditional 802.11b was licensed for omnidirectional service spanning only
100-150 metres (300-500 ft). By focusing the signal down to a narrow beam with a
yagi antenna it can instead operate reliably over a distance of many miles.
Rural Wireless-ISP installations are typically not commercial in nature and
are instead a patchwork of systems built up by hobbyists mounting antennas on
radio masts and towers, agricultural storage silos, very tall trees, or whatever
other tall objects are available. There are currently a number of companies that
provide this service. One is firenet1.com base out of Southaven, Mississippi.
T-1/DS-1 is a type of service which is possible for a rural customer desiring
broadband speeds, but the cost can be in the hundreds or thousands of dollars
per month depending on the distance from the provider.
These are highly-regulated services traditionally intended for businesses,
that are managed through Public Service Commissions in each state, must be fully
defined in PSC tariff documents, and have management rules dating back to the
early 1980s which still refer to teletypes as potential connection devices. As
such, T-1 services have very strict and rigid service requirements which drive
up the provider's maintenance costs and may require them to have a technician on
standby 24 hours a day to repair the line if it malfunctions. (In comparison,
ISDN and DSL are not regulated by the PSCs at all.)
People attempting to establish rural service via a Wireless ISP, ISDN, or T-1
will run into an additional cost issue, where the physical connection (or local
loop) is considered separate from the actual Internet service provided from a
Point of Presence (POP). This is as if you had to pay the water utility to rent
the water main in the ground, in addition to paying to get water delivered
through the main from the tower. For a T-1, for example, in the US the loop
alone may cost $1200 per month, and the 1.5 megabit per second business-class
Internet service (with a fixed IP address and a subnet) may cost an additional
$1000 per month. Attempting to reduce monthly costs by establishing your own
non-profit Wi-Fi network and sharing the T-1 connection costs has an additional
pitfall: your service provider may want to charge you an additional "ISP
reseller's fee" of $800 per month.
Broadband subscribers per 100 inhabitants, by technology, December 2005 in
the OECD (source)