3G - CDMA2000 1xEV-DO TECHNOLOGIES
CDMA2000 1xEV-DO (Evolution-Data Optimized) introduces new high-speed packet-switched transmission techniques that are specifically designed and optimized for a data-centric broadband network that can deliver peak data rates beyond 2 Mbps in a mobile environment. CDMA2000 1xEV-DO was approved as an IMT-2000 standard (cdma2000 High Rate packet Data Air Interface, IS-856) at the ITU Stockholm Conference in 2001.
CDMA2000 1xEV-DO Release 0 | CDMA2000 1xEV-DO Revision A (Rev A) | CDMA2000 1xEV-DO Revision B
CDMA2000 1xEV-DO Release 0
CDMA200 1xEV-DO Release 0 (Rel 0) offers high-speed data access of up to 2.4 Mbps and it was the first mobile broadband technology deployed worldwide, in 2002 in South Korea.
Key features of Rel 0 include:
- Broadband data: Provides a peak data rate of 2.4 Mbps in the forward link and 153 kbps in the reverse link in a single 1.25 MHz FDD carrier. In commercial networks, Rel 0 delivers average throughput of 300-700 kbps in the forward link and 70-90 kbps in the reverse link
- Offers an "always on" user experience
- Leverages the existing suite of Internet Protocols (IP), and hence supports IP-based network connectivity and software applications
- Applications: Supports broadband data applications, such as broadband Internet or VPN access, MP3 music downloads, 3D gaming, TV broadcasts, video and audio downloads. In many countries, it has been deployed as a DSL substitute.
In most all cases, CDMA2000 1xEV-DO devices include a CDMA2000 1X modem to be compatible with CDMA2000 1X and cdmaOne systems.
CDMA2000 1xEV-DO Release 0 network diagram
In addition to the air interface techniques described in the previous section on CDMA2000 1X, the following new high-speed packet data transmission enhancements are incorporated into CDMA2000 1xEV-DO Rel 0:
- High-Speed Packet-Switched Downlink Channelization Structure – bundling downlink resources into a packet data channel to enable high-speed data rate transmissions by combining all of the available Walsh codes and power
- Fast and Adaptive Modulation and Coding Schemes – to optimize the delivery of packets based on changes in the radio environment
- Fast and Adaptive Packet Data Scheduling – to rapidly adapt to changes in the radio link
- Fast Hybrid ARQ – to acknowledge correct receipt of data and retransmit erroneous data
- Incremental Redundancy Feedback in the Downlink – to increase the effective data rate in the uplink by terminating the transmission of a packet early if it is decoded earlier than expected
- Fast Downlink Rate Control – to rapidly adjust to changes in the radio environment
- Uplink Rate Control – to efficiently control the transmission of mobile devices
- Downlink Multiple User Separation – to efficiently assign the downlink channel to users
- Downlink Transmission Signaling – to indicate the downlink modulation and coding
- Closed Loop Downlink Power Control – to reduce power used by the base station
- Uplink Rate Detection – to enable correct decoding of uplink data traffic
- Short Transmission Time Intervals (TTI) – to accelerate the transmission of packets
CDMA2000 1xEV-DO Rel 0 Deployments
CDMA2000 1xEV-DO Rel 0 Devices
CDMA2000 1xEV-DO Revision A (Rev A)
Rev A is an evolution of CDMA2000 1xEV-DO Rel 0 that increases peak rates on reverse and forward links to support a wide-variety of symmetric, delay-sensitive, real-time, and concurrent voice and broadband data applications. It also incorporates OFDM technology to enable multicasting (one-to-many) multimedia content delivery.
Rev. A’s more symmetric uplink speeds enable users to send large files, email with attachments, high resolution photographs and personal videos from their mobile devices. With its low network latency, service tiering with Quality of Service (QoS) and IP-based broadband architecture, Rev A is able to support time-sensitive applications, such as Voice over IP (VoIP), Push-to-Talk (PTT) and video telephony. Rev A was launched in October 2006, and it is the only All-IP, advanced broadband technology commercially deployed today.
Key features of Rev A include:
- Improved broadband speeds : Provides a peak data rate of 3.1 Mbps in the forward link and 1.8 Mbps in the reverse link in a 1.25 MHz FDD carrier. In commercial networks, Rev A achieves average throughput of 450-800 kbps in the forward link and 300-400 kbps in the reverse link
- Higher spectral efficiency : Supports1.2 times Rel 0 forward link sector capacity and3.4 times reverse link sector capacity. Increased rate quantization on both forward and reverse link enables more efficient use air link resources, better network utilization and lower cost of delivery
- Increased Capacity – On both the forward and reverse link, Rev A allows operators to support more users and it improves the cost of delivering voice, data and multimedia services.
- Symmetry – By increasing uplink speeds, Rev A is the first commercially available wireless technology to deliver a true synchronic broadband experience. Symmetry is important for applications where users send packets of data as often as they receive them, such as receiving and sending email with attachments.
- Low latency : The average latency of Rev A is below 50 milliseconds, making it ideal for delay-sensitive applications.
- Advanced Quality of Service (QoS) mechanisms that support the prioritization and delivery of individual packets based on the type of application or user profile. These mechanisms ensure a consistent, high-quality user experience.
- All-IP: Internet Protocol (IP) is the foundation for CDMA2000 radio access networks. Like 1xEV-DO Rel 0, All-IP Rev A networks provide operators service flexibility and higher bandwidth efficiencies, which translate into greater control and significant cost savings.
- Advanced services : Enables the enhanced performance of real-time broadband, symmetric data link, and delay sensitive services such as VoIP, push-to-talk (PTT), push-to-media (PTM), video conferencing, multicasting, and rich 3D gaming with multiple players.
- Backward compatibility: Rev A networks support existing Rel 0 applications and devices. This backward compatibility preserves an operator’s previous network investments. Rev A it is backwards compatible with 1X and cdmaOne systems through multi-mode devices .
In addition to the air interface techniques used in CDMA2000 1X and 1xEV-DO Rel 0, the following new high-speed packet-switched uplink techniques are incorporated into CDMA2000 1xEV-DO Rev A:
- Fast Uplink Rate Control – to efficiently control the transmission of mobile devices
- Fast Hybrid ARQ in Uplink – to acknowledge correct receipt of data and retransmit erroneous data
- Incremental Redundancy Feedback in Uplink – to increase the effective data rate in the downlink by terminating the transmission of a packet early if it is decoded earlier than expected
- Uplink Channelization – to enable better control of the uplink data flows
- Short Transmission Time Interval (TTI) – to accelerate the transmission of packets
CDMA2000 1xEV-DO Rev A deployments
CDMA2000 1xEV-DO Rev A devices
CDMA2000 1xEV-DO Revision A: The Gateway to True Mobile Broadband Multimedia
By CDMA Development Group, August 2006
Mobile VoIP Over 1xEV-DO
By Paul Callahan, VP, Businesss Development, Airvana, July, 2006
CDMA2000 1xEV-DO Revision B
The Revision B (Rev B) is an evolutionary step of Rev A that consists of aggregating multiple EV-DO Rev A channels to provide higher performance for multimedia delivery, bi-directional data transmissions and VoIP-based concurrent services. The Rev B standard was published by the Third Generation Partnership Project 2 (3GPP2) under document number 3GPP2 C.S0024-B and by the Telecommunications Industry Association (TIA) and Electronics Industry Association as TIA/EIA/IS-856-B. Rev B will be commercially available in 2008.
Rev B builds on the efficiencies of Rev A by introducing the concept of dynamically scalable bandwidth. Through aggregation of multiple 1.25 MHz Rev A channels, Rev B enables data traffic to flow over more than one carrier and hence improve user data rates, latencies on both forward and reverse link. Peak data rates are proportional to the number of carriers aggregated. When 15 channels are combined within a 20 MHz bandwidth, Rev B delivers peak rates of 46.5 Mbps in forward link and 27 Mbps in the reverse link. With the 64-QAM scheme, the peak data rate in the forward link increase in a single 1.25 MHz carrier to 4.9 Mbps, an aggregated 5 MHz will deliver up to 14.7 Mbps and within 20 MHz of bandwidth up to 73.5 Mbps. By increasing the bandwidth, an operator can support more users per sector or lower their cost per megabyte to encourage longer usage. To achieve this performance, the 1.25 MHz carriers do not have to be adjacent to one another, thus giving operators the flexibility to combine blocks of spectrum from different bands. This is unique benefit of Rev B that is not available to WCDMA/HSDPA.
In addition to supporting mobile broadband data and OFDM-based multicasting, the lower latency characteristics of Rev B improve the performance of delay-sensitive applications such as VoIP, push-to-talk, video telephony, concurrent voice and multimedia and multiplayer online gaming. Rev. B also allows operators to consider the deployment of “hot zones” where the demand for data is high.