From HSPA to LTE… and beyond
New UMTS Forum White Paper explores mobile broadband evolutionary roadmap

13 February 2009: A white paper from The UMTS Forum charts the technical and commercial path towards a new generation of high-speed mobile broadband systems.

Titled Mobile Broadband Evolution: the roadmap from HSPA to LTE, the white paper takes a holistic view of tomorrow’s widely predicted ‘data explosion’. In the global context of rapid growth in voice and IP traffic over both fixed and mobile networks, the paper paints a compelling case for 3G LTE (Long Term Evolution) as a vital next step for operators to anticipate and exploit the challenges of tomorrow’s data-driven world.

Following the large-scale introduction of HSPA, 3G network operators are already experiencing a massive increase in non-SMS mobile data traffic. Driven by applications such as consumer video, new networks with lower carriage costs per bit will be required to satisfy sustained growth in mobile broadband traffic over the next decade and beyond.

The white paper argues that HSPA+ and LTE technologies – deployed either in new or refarmed spectrum – will deliver spectral efficiencies capable of providing the required performance. The emergence of LTE as the next technology of choice for both 3GPP and non-3GPP networks will also result in unprecedented global economies of scale, further improving the cost per bit characteristics of these networks.

Based on an all-IP core plus a new radio interface based on OFDM, LTE promises downlink peak data rates up to 300 Mbps with increased spectral efficiency and more capacity for simultaneous users in the same cell.

LTE offers exceptional flexibility in the use of operators’ current and future spectrum assets. It can be deployed in either paired or unpaired spectrum: and while its full potential will be realised in bandwidths of up to 20MHz, it is also quite feasible to deploy LTE in far smaller tranches of just a few Megahertz.

LTE’s low latency and fundamental support for packet services takes the mobile experience far closer to the look-and-feel of fixed access networks. Furthermore, flexible service provisioning for LTE operators will be complemented by simpler interworking with fixed networks.

“From a carrier’s point of view, the economics of LTE are compelling”, says UMTS Forum Chairman Jean-Pierre Bienaimé . “Manufacturers are offering a cost-effective route for 3G operators to migrate their radio networks to LTE by reusing parts of their existing infrastructure. Underpinning these technical arguments are simple considerations of size. With a global GSM/UMTS/HSPA footprint in excess of 3.5 billion customers, subscribers already benefit directly from incredible economies of scale manifested as affordable tariffs and a broad range of terminals at all price points from a few dollars upwards.”

LTE will usher in a new wave of high bit rate, interactive services. These will include high quality video conferencing and music/video streaming and downloads, P2P sharing of rich media, super-fast web browsing, real-time online gaming across both fixed and mobile networks, broadcast TV services and rapid completion of payment transactions via mobile.

The new white paper also looks further into the future, where new radio access technologies and more spectrum will eventually be needed to deliver anticipated volumes of IP traffic.

The ITU has already started the “IMT-Advanced” process: 3GPP is now working on the specifications of the LTE-Advanced technology that will satisfy IMT-Advanced requirements and will be based on further evolutions of LTE. It is envisioned that IMT-Advanced will support peak data rates of up to 100 Mbit/s for high mobility and as high as 1 Gbit/s for low mobility scenarios. It will also need to deliver worldwide roaming capability, the ability to interwork with other radio access systems, and compatibility of services with fixed networks.