While 3G gains commercial momentum, standardization bodies and R&D departments are already defining the next step in the evolution of WCDMA networks.
As penetration and use of packet data services increases and more high-bandwidth services are introduced, operators need to provide ever-higher data rates while maintaining or improving quality of service.
For WCDMA, the next step in meeting these requirements is the introduction of High Speed Downlink Packet Access (HSDPA), as specified by 3GPP Release 5. HSDPA improves the current WCDMA standard to facilitate data rates of up to 14Mbit/s in the downlink, reduce delay and provide between two and three times more capacity than current WCDMA systems.
HSDPA's capabilities are based on technological advances including shared channel transmission, 16QAM modulation, fast link adaptation and scheduling, and advanced requesting mechanisms ("soft-combining").
What is more, no new spectrum is needed for operators to roll out HSDPA and, as with WCDMA, it can simultaneously provide voice and data services on the same carrier.
The greatest beneficiaries of what is also referred to as WCDMA Evolved are applications such as file downloads, gaming, streaming services and wireless access to corporate LANs and intranets. For example, download times will typically be reduced from over four seconds to one second for a 30kB JPEG image and from over 130 seconds to just over four seconds for a 1MB MP3 audio file.
While HSDPA will enable more advanced wireless broadband applications, the next stage of WCDMA evolution is already under way, with the objective to further improve uplink capacity.
Read more about WCDMA Evolved at
http://www.ericsson.com/products/white_papers_pdf/wcdma_evolved.pdf.