What Is an EVDO Modem?

The abbreviation of CDMA2000 1xEV-DO is EVDO. EVDO (EV-DO) is actually an abbreviation of three words: Evolution (evolution) and Data Only. 1xEV means 'Evolution', which also means the development of the standard, and DO means Data Only (Later, in order to better express the meaning of this technology, Data Only was changed to Data Optimized, indicating that EV-DO technology is for CDMA2000 1X network is an effective means of enhancing data services).
CDMA2000 1x EV-DO Synonym EVDO generally refers to CDMA2000 1x EV-DO

Chinese name: Development of standards
Foreign name: CDMA2000 1x EV-DO

Short name: EVDO
begins at: Qualcomm's HDR technology

CDMA2000 1x EV-DO CDMA2000 1x EV-DO CDMA2000 1x EV-DO evolution process

The CDMA2000 1x EV-DO standard originated from Qualcomm's HDR technology. As early as 1997, Qualcomm proposed the concept of HDR (high-speed data) to the CDG. After continuous improvement and experiments, CDMA2000 1x was adopted in March 2000. The name of EV-DO submitted a formal technical solution to 3GPP2. CDMA2000 1xEV-DO is a stage of a path of CDMA2000 1x evolution (3G). This path has two stages of development. The first stage is called 1xEV-DO, or "Data Only". It allows operators to use a CDMA carrier frequency with the same bandwidth as IS-95 or CDMA2000 to achieve up to 2.4Mbps. The forward data transmission rate has been accepted as an international 3G standard by the ITU and is ready for commercialization. The second phase is called 1xEV-DV. 1xEV-DV stands for "Data and Voice". It can support both voice and data on a CDMA carrier frequency. In October 2001, 3GPP2 decided to use the L3NQS standard proposed by Lucent and Qualcomm as the framework, while absorbing some features of the 1xTREME standard proposed by Motorola and Nokia to formulate the 1xEV-DV standard. In June 2002, the standard was finalized, which can provide data transmission rates of 6Mbps or higher.

1x EV-DO is a CDMA2000 air interface technology optimized for high-speed packet data transmission. Two versions, Release 0 and Release A, have been developed. Among them, Release 0 can support non-real-time and asymmetric high-speed packet data services; Release A can support real-time and symmetric high-speed packet data services.

On the one hand, the market share of 1x EV-DO is constantly expanding; on the other hand, the future of 1x EV-DV is becoming increasingly uncertain. It can be considered that 1x EV-DO, as a more realistic evolution technology of CDMA2000 1x, will occupy an important position in the further development of CDMA2000 1x.

CDMA2000 1x EV-DO CDMA2000 1x EV-DO CDMA2000 1x EV-DO proposes background

In the late 1990s, as the demand for wireless access to the Internet increased, so did the demand for wireless packet data services. Although the wireless access technologies represented by wireless local area networks can provide higher bandwidth, their limitations in terms of security, billing, and coverage have limited their widespread application. The cellular mobile communication network can provide wide-area coverage, has a good billing system and a secure architecture. If combined with new high-speed wireless access technologies, it will have a bright application prospect in providing wireless Internet services. At the same time, considering the need to compete with the wired data network represented by ADSL, this new cellular network is required to provide at least the data bandwidth comparable to ADSL. In view of this, Qualcomm has developed HDR (High Data Rate) technology since 1996 and was accepted by the TIA / EIA as the IS-856 standard (Release 0 version) in 2000, also known as HRPD (High Rate Packet Data) or 1x EV-DO. 1x means it has the same RF bandwidth and chip rate as the CDMA2000 1x system, and has good backward compatibility; EV (Evolution) means it is an evolved version of CDMA2000 1x; DO (Data Optimization) means it is specifically targeted at Optimized technology for packet data services. 1x EV-DO was accepted by the ITU-R as one of the 3G technical standards in 2001.

CDMA2000 1x EV-DO CDMA2000 1x EV-DO CDMA2000 1x EV-DO Design Idea

The 1x EV-DO system was originally designed for non-real-time, asymmetric high-speed packet data services. High-speed transmission is a core functional requirement for the design of a 1x EV-DO system. High-speed means that based on limited bandwidth resources, cellular networks are used to provide mobile users with high-speed data services similar to wired networks (such as ADSL). When the 1x EV-DO system was originally designed, it was mainly designed to provide wireless Internet services such as web browsing and file downloading. They either had non-real-time characteristics and had no strict requirements on the QoS guarantee of the services; or they had asymmetric characteristics and required The transfer rate and throughput to the link are significantly higher than the reverse link. Obviously, as the business develops, the functional requirements for 1x EV-DO systems will also increase. In the CDMA2000 1x system, low-to-medium-speed data services and voice services are code-division multiplexed, sharing base station transmit power, spreading codes, and frequency resources. The base station compensates the influence caused by channel fading through fast closed-loop power control technology, thereby obtaining higher spectrum utilization efficiency. This is the best choice for low and medium speed data and voice services. However, for high-speed packet data services, this fast power control does not guarantee the system has a high spectrum utilization efficiency, especially when the high-speed packet data services and traditional voice services use code division to share frequency and base station power resources. Efficiency will be lower.

The basic design idea of the 1x EV-DO system is to separate high-speed packet data services from low-speed voice and data services, and use a separate carrier to provide high-speed packet data services, while traditional voice services and low- and medium-speed packet data services are provided by the CDMA2000 1x system. In this way, higher spectrum utilization efficiency can be obtained, and the network design is also more flexible. In the specific design, the compatibility between the 1x EV-DO system and the CDMA2000 1x system should be fully considered, and the interoperability of CDMA20001x / 1x EV-DO dual-mode terminals or Hybrid Access Terminals should be used to implement low-speed voice services. Common service with high-speed packet data services.

CDMA2000 1x EV-DO CDMA2000 1x EV -DO Development Status of CDMA2000 1x EV-DO

CDMA2000 1x EV-DO overview

Qualcomm started to develop HDR technology in 1996, and formed the 1x EV-DO standard in 2000. In 2002, 1x EV-DO products entered the commercial stage. As of the beginning of 2005, more than ten 1x EV-DO commercial networks have been established worldwide, and their markets The pace of change is gradually accelerating. The following describes the development of 1x EV-DO from three aspects, including standardization progress, commercial progress, and market prospects.

CDMA2000 1x EV-DO Standardization Progress

As a wireless extension of the Internet, 1x EV-DO was originally designed to provide asymmetric high-speed packet data services. To date, the 1x EV-DO air interface standard has developed Release 0 and Release A, corresponding to the TIA. The / EIA standards are IS-856-0 and IS-856-A, respectively.

IS-856-0 was released in October 2000. It supports a forward single user peak rate of 2.4576Mbit / s and a reverse single user peak rate of 153.6kbit / s. It is suitable for providing file-based downloads, web browsing and email. And other asymmetric packet data services.

In order to support some real-time multimedia services, Qualcomm enhanced the IS-856-0 in 2003, adding functions such as receive diversity, QoS guarantee, broadcast and channel equalization, and implemented baseband processing chips for terminals and systems. In order to upgrade, the introduction of zero-IF technology. However, these enhancements have not been released in a standard form.

With the development of multimedia data services, various new business forms continue to emerge, and requirements for system bandwidth and QoS guarantees have also increased. Due to the limitations of reverse link bandwidth and QoS guarantee, the 1x EV-DO Release0 system is difficult to meet the relevant requirements for business development. In March 2004, 3GPP2 released 1x EV-DO Release A, and was accepted as IS-856-A by TIA / EIA. IS-856-A supports a single user with a reverse peak rate of 1.8Mbit / s and a forward peak rate of 3.1Mbit / s. Multi-user packet and smaller packet encapsulation are used in IS-856-A to provide the fast access, fast paging, and low-latency transmission features required by real-time services to meet the different QoS requirements of different services; the introduction of multiple antennas Transmit diversity technology effectively improves the reliability of high-speed packet data in harsh wireless environments. With the development of the 1x EV-DO air interface standard, its A interface, terminal technical specifications, and new service specifications have also been formulated and continuously developed.

CDMA2000 1x EV-DO commercial progress

Since SKT launched the world's first 1x EV-DO commercial network in May 2002, 1x EV-DO has maintained rapid development momentum. As of January 2005, SKT, KTF, KDDI, Verizon, Vesper, Monet, etc.13 Each operator has successfully deployed a 1x EV-DO commercial network, and hundreds of 1x EV-DO terminals and more than ten network cards have entered commercial use. The number of 1x EV-DO users worldwide has exceeded 12 million.

At present, the vast majority of 1x EV-DO commercial systems and terminals are based on Release 0. A few equipment manufacturers are also developing or can provide 1x EV-DO devices based on Release 0 enhancements. 1x EV-DO Release A system products are expected to Entered commercial use at the end of 2005, and terminal products are expected to enter commercial use in 2006.

CDMA2000 1x EV-DO Market Prospect

The key to the success of 3G services is mainly whether the wireless data service can penetrate the hearts of the people and whether the content services provided can have great appeal to users. Operators in Japan, South Korea, and the United States have made use of rich content services such as high-quality music clips and high-definition movie clip downloads, which have greatly increased the traffic of data services and greatly increased the ARPU value.

On the one hand, 3G services require the network to have high data throughput and be able to provide high-speed data services. The technical characteristics of 1x EV-DO ensure this. 1x EV-DO can support all packet data services provided by CDMA2000 1x. For services with strict rate and QoS requirements, 1x EV-DO can provide better services and user experience. For example, for wireless data access services, the level of 1x EV-DO access services is close to the popular wired ADSL Internet access; for wireless data value-added services, 1x EV-DO can provide higher quality streaming media services and faster Audio and video large file download service.

CDMA2000 1x EV-DO Commercial Application

On the other hand, 3G services require close cooperation between operators, system manufacturers, terminal manufacturers and content service providers, and solve the problems on their industrial chain in a short period of time. First, operators and system manufacturers work together to solve network coverage and system stability issues in a short period of time. Operators provide a well-covered network for mobile streaming and other services, which can support business development; second, , Operators and terminal manufacturers work together to provide a variety of mobile phones that can support mobile streaming media and other services; Finally, operators and content providers work together to target the characteristics of mobile streaming media and other services in terms of content, combined with user use Habits and hobbies, jointly develop and quickly update the content of services such as mobile streaming.

At present, 1x EV-DO has achieved successful commercial applications in many countries. It has verified that 1x EV-DO is a wireless extension of the Internet and provides excellent performance in providing high-speed packet data services. It also indicates a broad market for 1x EV-DO. prospect.