What’s EVDO?

[ad_1]

EVDO is a high-speed wireless broadband protocol. Also known as EV-DO, 1xEvDO and 1xEV-DO, it is a leading third generation (3G) wireless data standard. Mobile devices using EVDO technology can upload and download data quickly, and the technology is always “on” whenever there is a signal from the wireless tower. Unlike a WiFi® connection, a device with EVDO doesn’t need to be near a wireless hotspot; instead, the mobile phone can become a hotspot itself and share its Internet connection with other devices.

Officially, the name defined by the Telecommunication Industry Association for this technology is “CDMA2000, High Rate Packet Data Air Interface”. The acronym EVDO is short for “Evolution, Data Only” or “Evolution, Data Optimized,” a reflection of the fact that it is the next evolution of the earlier Code Division Multiple Access 2000 (CMDA2000) family of wireless products. The EVDO standard was developed in 1999, but the protocol has since been updated to improve its speed.

3G e CDMA

3G is designed to transmit high-speed mobile voice and data to people on the go. Several competing technologies are involved in the development of 3G networks as technology companies work on the best way to handle the growing demand for wireless services around the world. Many companies that have invested in the development of 3G networks and technologies use the Code Division Multiple Access (CDMA) approach, which has proven very effective with mobile phone networks.

The biggest obstacle to implementing high-speed wireless networks is the lack of usable bandwidth or frequency range. Just as only so many radio stations can be squeezed onto the FM dial, only so much data can be transmitted across the available bandwidth. As user load increases, available frequencies become narrower and users may experience lag, data loss, and other problems. Therefore, providers have worked to find ways to use bandwidth more efficiently without sacrificing clarity and quality for their users.
How CDMA works
CDMA uses advanced mathematical techniques to allow multiple wireless devices to transmit simultaneously on the same radio frequency. Each device, such as a mobile phone, is assigned a unique mathematical signature. Transmitters apply this signature to the original signal and send a modified version. A receiver applies the reverse math operation to recover the original signal.
The term “CDMA” is used both to refer generically to a channel access method and to specific technologies that use that method as the backbone for radio transmissions. The intended meaning is usually clear from the context. CDMA2000, for example, is a data management standard that uses CDMA technology.
How EVDO works
Traditional wireless networks create a direct path between receiving and sending devices, just like traditional telephone networks. Instead, EVDO breaks the data into individual packets, the same data management technique used on the Internet. Each packet is sent independently of all other packets. This saves bandwidth for other devices to use; when neither party in a phone call is speaking, for example, the connection consumes no bandwidth. When you access an Internet site, no bandwidth is used until the site starts serving the web page.
The original EVDO protocol, called Revision 0, has a theoretical throughput of 2.4 megabits per second (Mbps). This is as fast as many wired DSL and cable broadband connections currently available in the United States. Upgrading to Revision A boosts speed to a theoretical 3.1 Mbps. A third update, to revision B, was released in January 2010, although it has not been fully deployed; Qualcomm, the developer, expects download speeds of up to 14.7 Mbps in some situations.
Qualcomm has produced impressive demonstrations of EVDO’s capabilities. In one, a video conference was conducted with a participant traveling by car at 60 mph (96 km/h). Transferring the large amounts of data required for video conferencing is a major challenge, especially at such speeds. In another demonstration, a phone call was made from a bullet train moving at over 150km/h.
UMTS e HSDPA
The biggest challenge for EVDO was the Universal Mobile Telecommunications System (UMTS). UMTS, sometimes known by its radio interface standard name, Wideband-CDMA (WCDMA), uses larger bands for data transmission. This approach may be less vulnerable to eavesdropping and jamming than other wireless technologies. However, data transfer speeds are slower than EVDO, with speeds up to 2 Mbps.
HSDPA, which stands for High-Speed ​​Downlink Packet Access, was built on top of WCDMA technology, but with a number of significant changes in how data is handled. This protocol is considered 3.5G or Enhanced 3G, a step above 3G but not quite fourth generation. HSDPA shares a transmission channel among multiple users and schedules data transfer to take advantage of the best possible conditions; this means that data can be sent to multiple users at the same time. Different speed versions of HSDPA are typically available to consumers, with download speeds ranging from 1.8 Mbps to 21 Mbps or higher.
How does this affect users?
One advantage of EVDO is that it uses the same transmission frequencies as existing CDMA networks. Since purchasing spectrum from regulatory agencies is extremely expensive, this reduces the cost of building and operating new networks. HSDPA, while offering the fastest download speeds with the highest service levels, can also be more expensive for the consumer.
Mobile Internet users should remember that the standard used for data transmission is usually network dependent; a Verizon cell phone in the US will have access to EVDO, for example, but not HSDPA. Users who will be traveling to foreign countries with wireless devices may want to check if they are supported on a particular network. For frequent travelers, you might want to consider investing in a device that works reliably on international networks to avoid problems with dropped calls, unable to send data, and other problems.
As new wireless standards develop, the quality of wireless services tends to improve. Various options are not available in all areas and may have different performance rates. Newer technologies can present unexpected problems and service plans can be more expensive. Early adopters may also find it difficult to access technical support and assistance, as technicians may not be familiar with the products they are using.

[ad_2]