CDMA EV-DO vs. HSPA Network Technology

The difference between CDMA EV-DO and HSPA Network Technologies

Both CDMA EX-DO and HSPA are network technologies, but there are some differences between them. CDMA EV –DO is a move towards cell phone technology that will be able to deliver data at rates higher than 2 Mbps.

Even though many of the EV-DO techniques are part of HSPA, HSPA is able to achieve spectral efficiency. This includes turbo coding and adaptive modulation schemes. HSPA is a packet based technology that in theory should be able to provide a maximum data rate of 14.4 Mbps downlink and 5.8 Mbps uplink.

CDMA EV-DO

As part of the standards set down by the 3GPP2 for CDMA 2000, there have been three releases of this technology:

  • CDMA2000 1xEV-DO Release 0 (Rel 0)
  • CDMA2000 1xEV-DO Revision A (Rev A)
  • CDMA2000 1xEV-DO Revision B (Rev B)

Release O and Revision A are the releases that are currently in use. They have 2.4 Mbps and 3.1 Mbps downlinks and 153Kbps and 1.8 Mbps uplinks respectively. The radio channels use a bandwidth of 1.25MHZ. This means that the data rates are lower when compared to UMTS. However, these networks are important because of the full packet based network in the backend. You can receive a good quality VoIP with Revision A networks because they are so similar to HSPA. There is no data available for Revision B networks because they have not yet been used commercially.

HSPA (High Speed Packet Access)

This is the term used to describe the 3GPP Release 5, also known as HSDPA and 3GPP Release 6, also known as HSUPA. It does have a much higher rate of data as compared to that of 3G and GPRS. Release 7 (HSPA+ and HSPA) and beyond also belongs in this family and will correspond with the 3G LTE network standards. It is usually referred to as the technology used for 3.5G networks. In theory, the downlink speed can reach a maximum of 14.4 Mbps and the uplink speed can reach a maximum of 5.8 Mbps which is about three or four times higher than the current 3G speeds and fifteen times higher than the current GPRS.

Current networks have the ability to provide 3.6Mbps downlink and from 500kbps to 2 Mbps uplink when a radio channel bandwidth of 5MHz. In order to upgrade the networks from 3G to HSPA, it is necessary to change the existing downlink to HSDPA technology (High Speed Downlink Packet Access) and change the existing uplink to HSUPA technology (High Speed Uplink Packet Access).

For the majority of WCDMA networks these upgrades were mostly software related and the hardware wasn’t affected. With higher order digital modulation, such as 16QAM to 64QAM, higher data rates are also possible with MIMO.

Summary

  1. The radio interface bandwidth for CDMA EX-DO is 1.25MHz and the bandwidth for HSPA is 5MHZ.
  2. HSPA downlink data rates are much faster at 14.4 Mbps, compared to those of CDMA at 2Mbps.
  3. The data rates for CDMA uplinks start at 153kbps in Release 0 and those for HSUPA are 5.8Mbps
  4. CDMA is standard for 3G networks and HSPA is considered to be for 3.5G.