Evolution-Data Optimized
is a telecommunications standard for the wireless transmission of data through radio signals, typically for broadband Internet access.
EV-DO is an evolution of the CDMA2000 (IS-2000) standard which supports high data rates and can be deployed alongside a wireless carrier's voice services.
It is a part of the CDMA2000 family of standards and has been adopted by many mobile phone service providers around the world particularly those previously employing CDMA networks.
The EV-DO feature of CDMA2000 networks provides access to mobile devices with forward link air interface speeds of up to 2.4 Mbit/s with Rel.
B) was published, whose features include the ability to bundle multiple carriers to achieve even higher rates and lower latencies (see TIA-856 Rev.
B involves a software update of the cell site modem, and additional equipment for new EV-DO carriers.
Initially, the standard was called High Data Rate (HDR), but was renamed to 1xEV-DO after it was ratified by the International Telecommunication Union (ITU) under the designation TIA-856.
Originally, 1xEV-DO stood for "1x Evolution-Data Only", referring to its being a direct evolution of the 1x (1xRTT) air interface standard, with its channels carrying only data traffic.
This means that a single mobile has full use of the forward traffic channel within a particular geographic area (a sector) during a given slot of time.
The modulation to be used to communicate with a given mobile unit is determined by the mobile device itself; it listens to the traffic on the channel, and depending on the receive signal strength along with the perceived multi-path and fading conditions, makes a best guess as to what data-rate it can sustain while maintaining a reasonable frame error rate of 1-2%.
It then communicates this information back to the serving sector in the form of an integer between 1 and 12 on the "Digital Rate Control" (DRC) channel.
If after decoding the first slot the mobile is able to determine the entire data packet, it can send an early acknowledgement back at that time; the remaining three sub-packets will be cancelled.
In the closed loop, the reverse link power is adjusted up or down 800 times a second, as indicated by the serving sector (similar to 1x).
[6] All of the reverse link channels are combined using code division and transmitted back to the base station using BPSK[7] where they are decoded.
Also included were protocols that would decrease connection establishment time (called enhanced access channel MAC), the ability for more than one mobile to share the same timeslot (multi-user packets) and the introduction of QoS flags.
A, and provides the following enhancements: Qualcomm early on realized that EV-DO was a stop-gap solution, and foresaw an upcoming format war between LTE and determined that a new standard would be needed.
UMB's use of OFDMA would have eliminated many of the disadvantages of the CDMA technology used by its predecessor, including the "breathing" phenomenon, the difficulty of adding capacity via microcells, the fixed bandwidth sizes that limit the total bandwidth available to handsets, and the near complete control by one company of the required intellectual property.
[14][15] In November 2008, Qualcomm, UMB's lead sponsor, announced it was ending development of the technology, favoring LTE instead.
[16] However, during the ongoing development process of the 4G technology, 3GPP added some functionalities to LTE, allowing it to become a sole upgrade path for all wireless networks.
