Every day, the communications industry’s media run stories about LTE. As the fastest ever growing communications technology, LTE is certainly taking center stage. After all, LTE is obviously where the 4G action is. Right?
Well, let’s not forget that HSPA is the world’s most widely deployed radio access technology, and is likely to remain so for many years, servicing more and more subscribers. The numbers speak for themselves. HSPA+ is deployed in 457 commercial networks in almost 200 countries. HSPA connections are also showing vast increases year on year. Estimated to grow at a CAGR of about 30% between 2011 and 2016, they will hit 2.5 billion in 2016, driven by a mass market that can choose from over 3,000 available devices.
What’s more, the performance of HSPA is evolving rapidly through standardization, and HSPA is fast becoming a viable technology that can deliver a 4G-like service either as an alternative to, or alongside, LTE networks.
The latest developments of HSPA are being finalized in 3GPP Release 11. They allow HSPA to meet the ITU’s IMT-Advanced requirements, which set minimum targets for the peak spectral efficiency, average and cell edge spectral efficiency, as well as for issues such as spectrum flexibility, handover interruption and system latency. In other words, they specify the system’s ability to give subscribers a 4G experience.
The key developments that turn HSPA into a real 4G contender are:
- 8 carrier (8C) aggregation, giving up to eight times faster data speeds. 8C-HSDPA builds on the dual-band HSDPA concept present in the standards since Release 9
- 4×4 MIMO (Multiple Input, Multiple Output) in the downlink, roughly doubling peak data rates and system capacity for devices with four receiver antennas
- Uplink improvements that increase the peak data rate, user specific performance and cell capacity
- Multiflow which increases downlink user throughputs at the cell edge
Nokia Siemens Networks has driven much of this evolution, and has long been working to make HSPA a viable 4G technology. In December 2010, we published our vision for Long Term HSPA Evolution, much of which is now included in 3GPP Release 11. Together with T-Mobile USA, we have been promoting the Long Term HSPA Evolution standard that will allow operators to achieve peak data rates of more than 650 megabits per second (Mbps).
Together with Qualcomm, we also originated HSPA+ Multiflow, which allows devices located close to the edge of a mobile base station’s cell to connect with a second base station serving a neighboring cell. By deploying HSPA+ Multiflow in its network, an operator can double the throughput (data speeds) for users at the cell edge. Again with Qualcomm, we were the first to demonstrate an HSPA+ data call with peak throughput of 336 Mbps, showing how HSPA+ speed and capacity can be increased by using multi-carrier and multiband technology.
Working with Nokia Siemens Networks, operators can realize the full potential of their existing HSPA networks and evolve them into a complementary offering to their LTE-based 4G services.
Find out more about how HSPA is becoming more able to deliver higher performance in a new White Paper entitled “Long Term HSPA Evolution meets ITU IMT-Advanced requirements”.
This post is by Lauri Oksanen, head of research and technology, Nokia Siemens Networks.