What is WAP

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WAP, which stands for wireless access point, is a device used for the formation of a wireless network through connection of wireless communication devices. It often connects to a wired network, enabling it to transmit data between wired and wireless devices.

A larger, “roaming”-enabled network may be formed by linking together several WAPs. A WAP is also able to serve as the arbitrator of a network, since it is able to negotiate the durations for which each nearby client device will be able to transmit data over the network. However, this function is generally bypassed, with most IEEE 802.11 networks implementing a distributed pseudo-random algorithm instead.

In the early 2000’s, Wi-Fi WAPs experienced a popularity boost among consumers. This is because of the advantages that having a Wi-Fi WAP offers, such as: low cost; easy installation, as wireless networks do not require having to install cables through walls and ceilings; and mobility, since users are now free to roam, using a device that does not require being cabled to the wall.

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There are various ways in using WAPs to form networks. Inside households, there is generally only one WAP, often a wireless router, used to connect all the computers within. For large businesses, several WAPs are usually attached to a wired network to provide wireless access to the local area network (LAN) in the office.

The end user is enabled a full network connection, as well as mobility within the WAP range, so the WAP serves as a gateway, enabling clients to access the wired network. Another way would be to bridge two wired networks using WAPs in conditions that wired networks would be unsuited for.

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Another would be to make use of the wireless topology known as a lily-pad network. A lily-pad network is a series of WAPs deployed over a large geographical area, with each WAP connected to a different network in order for multiple networks to be interconnected. As a result, wireless clients can connect to the Internet using hot spots in the network, regardless of which particular network they have attached to for the moment. Clients are able to roam over a large area while staying connected.

The average range of communication of an IEEE 802.11 WAP is a 100 m radius for 30 client devices, although there are a number of variables that affect this, such as indoor or outdoor placement, altitude, power output of the device, signal interference caused by other devices operating on the same frequency, obstructions within the area, weather, antenna type, and operating radio frequency. Repeaters and reflectors, which are able to bounce or amplify radio signals, may be used in order to extend the range of WAPs.

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Since wireless networks broadcast messages using radio, a network becomes prone to eavesdropping and unauthorized access to its services by nearby users. As a solution to this problem, wireless traffic encryption schemes have been developed. The first of these, Wired Equivalent Privacy (WEP), had a lot of weaknesses, so new schemes such as Wi-Fi Protected Access (WPA) and the IEEE 802.11i standard (also known as WPA2) were developed. Provided that a strong enough password is used, WPA and WPA2 are both considered secure.

What is EDGE

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EDGE, short for Enhanced Data rates for GSM Evolution, and also known as Enhanced GPRS (EGPRS), is a standard of technology in wireless telecommunications introduced in 2003 that increases data transmission rates and improves data transmission reliability in GSM-enabled mobile phones.

It is usually classified as a second and three-quarters generation (2.75G) technology because although it fits the International Telecommunications Union criteria to qualify as third generation (3G) technology, it runs at a slower network speed (up to 236.8 kbps for 4 timeslots, 473.6 kbps for 8 timeslots).

It is also classified as 2.75G technology because of its variability: EDGE devices have different classes. EDGE devices of Class 3 and below only qualify as second generation (2G), but devices of Class 4 and above qualify as 3G.

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EDGE may be used for any packet-switched application, for example, connecting to the internet. The increased data capacity of EDGE makes it important for the use of high-speed data applications such as video services and other multimedia.

Upgrading to EDGE is simple for existing GSM and GPRS networks, as it is a bolt-on enhancement, requires no hardware or software changes to be made in GSM core networks, and is able to function on any network with GPRS deployed on it.

However, EDGE does require some modification to base stations, such as installation of EDGE-compatible transceiver, as well as upgrade of the base station subsystem (BSS) to support EDGE. Upgrading to EDGE also requires new mobile terminal hardware and software for decoding and encoding the new modulation and coding schemes, as well as for carrying higher user data rates in order to implement new services.

EDGE uses nine modulation and coding schemes (MCS). One of these is Gaussian minimum-shift keying (GMSK), and another, used for the upper five MCS, is 8-phase shift keying (8-PSK). In EDGE, a 3-bit word is produced for every change in carrier phase, effectively tripling the gross data rate that GSM provides. Similarly to GPRS, EDGE employs a rate adaptation algorithm that adapts the MCS according to the quality of the radio channel, inclusive of the data transmission’s bit rate and robustness.

Incremental Redundancy is a new technology for EDGE that was not included in GPRS. In this process, redundancy information is sent to be combined in the receiver, rather than retransmitting disturbed packets. The probability of correct decoding is increased as a result of this process.

There is a new technology, EDGE Evolution, that serves as an improvement on EDGE. It features the following enhancements: reduced latency, possibly going down to 100 ms, accomplished by using dual carriers and lowering the Transmission Time Interval from 20 ms to 10 ms; bit rates that are increased up to 1 Mbps peak speed; a higher symbol rate and higher-order modulation, using 32 Quadrature Amplitude Modulation (32QAM) and 16QAM rather than 8-PSK; turbo codes to improve error correction; and better signal quality, achieved through the use of dual antennas.