For both wired and wireless technology, the range of transmission is an issue. You can't move your laptop 15 feet from the wall jack when depending on a 10-foot cable. Similarly, you can't go out for a jog and expect your in-home cordless phone to keep a connection five miles away from its receiver. But if you get either a 20-foot cable or a wireless connector of sufficient power, you can move your laptop 15 feet away from the wall jack; and if you get a cellular phone, you can go jogging five miles away from your house and still take calls (as long as your service provider has a reasonable antenna set up).
The methods of connection and ranges of service available vary in wireless technology just as they do in wired technology. Home telephones with a wireless handset have a more limited range than cellular phones; infrared transmissions have a more limited range than radio-wave (including microwave) transmissions. Different types of wireless solutions can communicate ten feet, ten miles, or with a satellite in orbit.
Fixed line Connectivity
ADSL is a modem technology on the access network, which changes the existing infrastructure of the copper pair from the customer's house and the entire communications network, into a broadband network from end to end. ADSL enables, under optimum conditions, the transfer of multimedia, video, audio, high-speed Internet, by means of the existing access network up to a speed of 8 Mbps from the exchange to the subscriber, and up to 768 Kbps from the subscriber to the exchange (hence the name "asymmetric subscriber line").
The basic idea behind the technology is the need to transfer large amounts of information from the exchange to the subscriber's home (downloads of games, movies, etc.) while in the upstream channel (from the subscriber's home to the x exchange) a slower channel is sufficient, enabling communication with the content provider, sending emails or uploading to FTP servers.
ADSL technology uses the existing copper infrastructure deployed all over the country, making the broadband network possible without having to set up a new infrastructure. The technology enables maximum utilization of the typical bandwidth of the copper lines by means of complex data processing and encoding. Instead of using frequencies of 4 kHz, as was done until now, we use a range of frequencies between 0 KHz and 1.1 MHz, where standard ADSL system use 256 frequency channels (for the information moving downstream to from the exchange to the subscriber and for the upstream channel) with a bandwidth of 4 KHz per channel, thus enabling the transfer of much more information.
Satellites are ideal for Internet and private network access over long distances and to remote locations. Satellite based IP connections provide an ubiquitous and instantaneous solution to companies seeking to include into their corporate network subsidiaries and production facilities, also in regions with a poor telecommunications infrastructure.
Fiber Line connectivity
An optical fiber (or fibre) is a glass or plastic fiber that carries light along its length. Fiber optics is the overlap of applied science and engineering concerned with the design and application of optical fibers. Optical fibers are widely used in fiber-optic communications, which permits transmission over longer distances and at higher data rates (a.k.a "bandwidth") than other forms of communications. Fibers are used instead of metal wires because signals travel along them with less loss, and they are also immune to electromagnetic interference. Fibers are also used for illumination, and are wrapped in bundles so they can be used to carry images, thus allowing viewing in tight spaces. Specially designed fibers are used for a variety of other applications, including sensors and fiber lasers.
Light is kept in the "core" of the optical fiber by total internal reflection. This causes the fiber to act as a waveguide. Fibers which support many propagation paths or transverse modes are called multi-mode fibers (MMF). Fibers which can only support a single mode are called single-mode fibers (SMF). Multi-mode fibers generally have a larger core diameter, and are used for short-distance communication links and for applications where high power must be transmitted. Single-mode fibers are used for most communication links longer than 200 meters.
Joining lengths of optical fiber is more complex than joining electrical wire or cable. The ends of the fibers must be carefully cleaved, and then spliced together either mechanically or by fusing them together with an electric arc. Special connectors are used to make removable connections.