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Access point base station
From Wikipedia, the free encyclopedia
An Access Point Base Station - sometimes called a femtocell, is a scalable, multi-channel, two-way communication device extending a typical base station by incorporating all of the major components of the telecommunications infrastructure. A typical example is a UMTS access point base station containing a Node-B, RNC and GSN with only an Ethernet (or ATM/TDM) connection to the Internet or Intranet. Application of VoIP allows such a unit to provide voice and data services in the same way as a normal base station, but with the deployment simplicity of a WiFi access point. Other examples include CDMA-2000 and WiMAX solutions. The main benefits of an Access Point Base Station are its simplicity of deployment, low-cost and scalable design. Design studies have shown that access point base stations can be designed to scale from simple hot-spot coverage through to large deployments by racking such units into full-scale base-stations.
Access Point Base Stations are stand-alone units that are typically deployed in hot-spots, in-building and even in-home. Variations include attaching a WiFi router to allow a WiFi hot-spot to work as back-haul for a cellular hot-spot, or vice-versa.
Femtocells work with handsets compliant with existing RAN technologies (see UMA), a major benefit of introducing these elements. The reuse of existing RAN technologies, however, also creates problems since introduction of these elements represents a significant operational challenge due to introduction of a large number of potential sources of interference with the existing mobile network.
Femtocells typically rely on the Internet on connectivity with the mobile core. This reduces backhaul expenses for mobile operators, but will introduce security risks that have not been considered in the existing standards.
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[edit] History
In 2002, a group of engineers at Motorola in Swindon UK started a skunkworks team, called the AFG, to develop new technologies. Some of their major achievements included the world's smallest full power UMTS base station, one of the first demonstrations of television to mobile, and the invention and development of the access point base station.
[edit] Regulatory issues
Although a panacea for straightforward system deployment, access point base stations, in common with all other public communications systems are, in most countries, required to comply with legal intercept requirements. This has implications on the type of network to which access point base stations are attached, and in some cases mean that a simple 'WiFi-like' access point base station cannot be deployed at all.
Other regulatory issues, which may eventually be overcome, relate to the requirement in most countries, for the operator of a network to be able to show exactly where each base-station is located. There are issues in this regard for access point base stations sold to consumers for home installation, for example.
Finally, licensed spectrum allocation is made to operators on a fee basis, and deployment of equipment must meet the strict requirements of the spectrum allocation. To make best use of spectrum, operators use frequency and cellular planning tools to optimise the best coverage for a given amount of spectrum. The introduction of access point base stations using licensed spectrum that are sold directly to the customer has implications for frequency and cellular planning since an unexpectedly located access point base station can be an interferer to other closely located base stations.
[edit] References
- See also WiFi access point
