What is Evdo?

EVDO is a protocol for high -speed wireless broadband. It is also known as EV-do, 1xevdo and 1xev-do, it is one of the main wireless data standards of the third generation (3G). Mobile devices that use EVDO technology can quickly record and download data and technology is always "ON" whenever there is a signal from the wireless tower. Unlike WIFI® connection, EVDO devices may not be near wireless hotspot; Instead, the mobile phone can become a hotspot itself and share your Internet connection with other devices. The abbreviation EVDO is short for "evolution, only data" or "evolution, data optimized", reflects the fact that this is the further development of the previous code distribution of multiple access 2000 (CMDA2000) wireless products. The EVDO standard was developed in 1999, but the protocol has been upgrading its speed since then.

3G and CDMA

3G is designed to transmit voice and high -speed mobile data to people on travels. Several competing technologies are involved in the development of the 3G network, as technology companies are working on the best way to manage demand for installation without wireless services around the world. Many companies invested in the development of networks and 3G technologies use access to the code division divisions (CDMA), which proved to be highly effective for mobile phone networks.

The largest obstacle to the implementation of high -speed wireless networks is the lack of bandwidth or the range of usable frequencies. Like only so many radio stations, you can push the FM on the FM dial, only so much data can be transferred through the available bandwidth. As the user's load increases, the available frequencies are tightened and users can experience delay, drop data, and other awakening. So providers are working to find ways to use the bandwidth more efficiently without sacrificing clarity and KV for their usersalite.

how does CDMA

work

CDMA uses advanced mathematical techniques to allow more wireless devices to transmit to the same radio frequency simultaneously. Each device, such as a mobile phone, is assigned a unique mathematical signature. The transmitters will use this signature on the original signal and submit the modified version. The receiver applies inversion of mathematical operations to restore the original signal.

The term 'CDMA' is used both to indicate the access to the channel and the specific technologies that use this method as a spine for radio transmission. The intended meaning is usually clear from context. For example, the CDMA2000 is a standard for data processing that uses CDMA technology.

How does evo

work

traditional wireless networks create a direct path between receiving and sending equipment, as well as traditional telephone networks. Instead, EVDO divides data into individual packets, the same technique for processing the data used on the Internet. Every packet isSending independently of all other packets. This saves the bandwidth for use by other devices; For example, if no party calls a phone call, the connection consumes no bandwidth. When access to the Internet is, no bandwidth is used until the site starts sending a web page.

The original EVDO protocol, called revision 0, has a theoretical permeability of 2.4 megabites per second (MBPS). It is as fast as many widespread DSL and cable connections that are currently available in the United States. Upgrade to revision and increases speed to a theoretical 3.1 Mbps. The third upgrade to revision B was issued in January 2010, although not fully deployed; The developer Qualcomm predicts download speeds in some situations up to 14.7 Mbps.

Qualcomm has created an impressive demonstration of the abbey F EVDO. On one, a video conference with a passenger participant in a car was 60 km / h (96 km / h). Transfer of large amounts of data needed for videoThe conference is the main challenge, especially at such speeds. During the next demonstration, the phone call was listed from a bullet moving exceeding 150 mph (240 km/h).

UMTS and HSDPA

The biggest challenge for EVDO was the universal mobile telecommunications system (UMTS). UMTS-KTERY is sometimes known as its standard interface interface, broadband CDMA (WCDMA)-uses larger belts to transfer data. This approach may be less vulnerable to resistance and interference than some other wireless technologies. However, data transfer speeds are slower than EVDO, with speeds of up to 2 Mbps.

HSDPA, which means high -speed access to downlink packets, was built on WCDMA technology, but with a number of significant changes in the way the data is dealing with. This protocol is considered 3.5 g or improved 3G, step above 3G, but not the fourth generation. HSDPA shares one transmission channel among multiple users and schedules data transmission to make use of the best possible conditions; This means that DAtta can be sent to multiple users simultaneously. Different speed versions of HSDPA are usually available for consumers, with download speeds ranging from 1.8 Mbps to 21 Mbps or higher.

How does this affect users?

The advantage of EVDO is that it uses the same broadcast frequency as the existing CDMA network. Since the purchase of spectrum from regulatory agencies is extremely expensive, it reduces the cost of construction and use of new networks. HSDPA, while offering faster download speeds with higher service levels, can also be more expensive for consumers.

Mobile Internet users should remember that the standard is used for data transfer, usually depends on the network; For example, Verizonuv's mobile phone will have access to EVDO, but not HSDPA. Users who travel in foreign countries with wireless devices may want to check if they are supported in a given network. For frequent travelers, it may be appropriate to consider investing in a device that BUDE to work reliably on international networks to avoid problems with released calls, inability to send data and other problems.

As new wireless standards develop, the quality of wireless services tends to improve. Different options are not available in all areas and may have a different level of power. Newer technologies can be supplied with unexpected breaks and service plans can be more expensive. Soon adoptors may also be difficult to gain access to technical support and help, as technicians may not be so familiar with the products they use.