It is wise to understand the technologies involved in a broadband. The way you access the Internet using a broadband connection can vary greatly depending on the technology used. The speed and accuracy of data transfer rely mainly on the type of broadband connection you are using. The different broadband technologies are:
Cable
Digital Subscriber Line (DSL)
ADSL (Asymmetric Digital Subscriber Line)
SDSL (Symmetric Digital Subscriber Line)
Satellite
Wireless
Broadband via Cable
Cable broadband pioneered the way to high speed Internet in the late nineties. Internet service is delivered through cable infrastructure that comprises primarily of the (i) cable modem terminating system (CMTS) - at the headend of the cable company, (ii) the existing coaxial cable networks (belonging to the cable TV network) and (iii) cable modem (CM) - at the users end. The pre-existing network is shared to deliver cable and broadband as well. The cable modem facilitates access of the digital signals sent over the cable lines. The capacity of this broadband facility is about 10 Mbps.
Pros and cons of cable broadband
Cable broadband is a top option for long distances and can be made available to all houses that have a cable connection. It is twice as fast as DSL and is easy on the pocket too. Installation is simple and the providers render good technical support. However, the down side of using cable broadband is that it uses a shared line and hence can pose security threats. It is traffic sensitive, in that, when many users are logged in simultaneously, speed drops. Cable broadband uses shared bandwidth and subscribers have no option of buying broadband standalone.
Digital Subscriber Line
DSL technology utilises telephone lines to broadcast digital signals. Digital signals are carried over telephone lines and are filtered using micro filters that separate internet data (more than 4 KHz) from voice data (less than 4 KHz). DSL is more secure than cable broadband because it uses a dedicated bandwidth instead of a shared bandwidth. It has its own disadvantages too. While urban areas see a lot of DSL connections, the rural areas don't. Furthermore these services are expensive too. It is distance sensitive, the longer the distance from the telephone exchange, the lesser the speeds achieved are.
DSL operates in many ways but the major two are - ADSL and SDSL.
ADSL Asymmetric Digital Subscriber Line
In ADSL, the upstream and downstream values are not the same, they are asynchronous. The download speeds are always higher than the upload speeds. This type of connection is ideal for home usage.
SDSL (Symmetric Digital Subscriber Line)
Both the download and upload limits are the same and hence the name symmetric DSL. These services are well suited for business purposes. Though these signals are carried over copper wires, it is not the traditional telephone lines that they rely on. Instead, special lines are deployed for this purpose.
Satellite Broadband and its types
While DSL and cable cater to urban broadband needs, there are places in rural areas were the same is not feasible. Satellite broadband is promising in such situations. Satellites provide wireless high-speed Internet access that is received by a dish antenna installed at the user end. There are one-way and two-way satellite broadband connections. One way connections supply the downlink but the uplink is provided by another system like a dial-up system.
Some drawbacks
On the other hand, cost of installation is high and another drawback is latency. As the signals have to travel long distances (from the user end to the satellite in geostationary orbit and all the way back) in this type of connection, time delays called latency need to be encountered. Though this type of connection offers high speeds compared to dial-up it is slow compared to its broadband counterparts.
Wireless broadband
Using radio point-to-point or point-to-multipoint microwaves in varying frequencies to provide a link between the subscriber and the operator's network is accomplished by wireless broadband. Wireless broadband reaches those areas (especially urban places) where the other technologies have not been able to provide connectivity. This type of Internet connection provides the advantages of cable and DSL.
How it works?
There are two categories of wireless broadband - one requiring line-of-sight (LOS is an unhindered view from transmitter to receiver) and the other that does not requires LOS, called non line-of-sight (NLOS is transmission over a partially obstructed path). LOS needs an aerial fitted at the point of reception while this is not a requirement for NLOS. Satellite broadband requires LOS and cellular technologies like GSM, CDMA, WiFi etc do not require LOS. Therefore, in terms of deployment and network coverage NLOS types are advantageous.
