ADSL

Asymmetric Digital Subscriber Line (ADSL) is a form of DSL, a data communications technology that enables faster data transmission over copper telephone lines than a conventional voiceband modem can provide. It does this by utilizing frequencies that are not used by a voice telephone call.[1] A splitter - or microfilter - allows a single telephone connection to be used for both ADSL service and voice calls at the same time. ADSL can generally only be distributed over short distances from the central office, typically less than 4 kilometres (2 mi), but has been known to exceed 8 kilometres (5 mi) if the originally-laid wire gauge allows for farther distribution.

At the telephone exchange the line generally terminates at a DSLAM where another frequency splitter separates the voice band signal for the conventional phone network. Data carried by the ADSL is typically routed over the telephone company's data network and eventually reaches a conventional internet network.

Fiber to the node (FTTN)

Fiber to the Node (FTTN), also called fiber to the neighborhood or fiber to the cabinet (FTTCab), is a telecommunication architecture based on fiber-optic cables run to a cabinet serving a neighborhood. Customers connect to this cabinet using traditional coaxial cable or twisted pair wiring. The area served by the cabinet is usually less than 1,500 m in radius and can contain several hundred customers. (If the cabinet serves an area of less than 300 m in radius then the architecture is typically called fiber to the curb.)

Fiber to the node allows delivery of broadband services such as high speed internet. High speed communications protocols such as broadband cable access (typically DOCSIS) or some form of DSL are used between the cabinet and the customers. The data rates vary according to the exact protocol used and according to how close the customer is to the cabinet.

Unlike the competing fiber to the premises (FTTP) technology, fiber to the node can use the existing coaxial or twisted pair infrastructure to provide last mile service. For this reason, fiber to the node costs less to deploy. However, it also has lower bandwidth potential than fiber to the premises.

Fiber to the premises

Fiber to the premises (FTTP) is a form of fiber-optic communication delivery in which an optical fiber is run directly onto the customers' premises. This contrasts with other fiber-optic communication delivery strategies such as fiber to the node (FTTN), fiber to the curb (FTTC), or hybrid fibre-coaxial (HFC), all of which depend upon more traditional methods such as copper wires or coaxial cable for "last mile" delivery.

Fiber to the premises can be further categorized according to where the optical fiber ends:

FTTH (fiber to the home) is a form of fiber optic communication delivery in which the optical signal reaches the end user's living or office space.

FTTB (fiber to the building) is a form of fiber optic communication delivery in which the optical signal reaches the private property enclosing the home or business of the subscriber or set of subscribers, but where the optical fiber terminates before reaching the home living space or business office space, with the path extended from that point up to the user's space over a physical medium other than optical fiber (for example copper loops).

Wi-Fi

Wi-Fi networks use radio technologies called IEEE 802.11 to provide secure, reliable, fast wireless connectivity. A typical Wi-Fi set-up includes one or more access points (APs) and one or more clients. An AP broadcasts its SSID (service set identifier, or "network name") via packets that are called beacons, which are usually broadcast every 100 ms. The beacons are transmitted at 1 Mbit/s, and are of relatively short duration and therefore do not have a significant effect on performance. Since 1 Mbit/s is the lowest rate of Wi-Fi it assures that the client that receives the beacon can communicate at at least 1 Mbit/s. Based on the settings, the client may decide whether to connect to an AP. If two APs of the same SSID are in range of the client, the client firmware might use signal strength to decide with which of the two APs to make a connection.

The Wi-Fi standard leaves connection criteria and roaming totally open to the client. This is a strength of Wi-Fi, but also means that one wireless adapter may perform substantially better than another. Since Wi-Fi transmits in the air, it has the same properties as a non-switched wired Ethernet network, and therefore collisions can occur. Unlike a wired Ethernet, and like most packet radios, Wi-Fi cannot detect collisions, and instead uses an acknowledgment packet for every data packet sent. If a sender receives no acknowledgement within a certain time, the sender retransmits the corresponding packet. Also, a medium reservation protocol can be used when excessive collisions are experienced or expected (request-to-send and clear-to-send used for collision avoidance or CA) in an attempt to avoid collisions.

A Wi-Fi network can be used to connect computers to each other, to the Internet, and to wired networks (which use IEEE 802.3 or Ethernet). Wi-Fi networks operate in the unlicensed 2.4 GHz (802.11b/g/n) and 5 GHz (802.11a/n) radio bands, with an 11 Mbit/s (802.11b) or 54 Mbit/s (802.11a or g) data rate. They can provide real-world performance similar to that of the basic 10BASE-T wired Ethernet networks.