Core decisions begin with HSPA

The way people communicate, stay informed and are entertained has changed dramatically over the past several years. Two major factors driving this change have been the Internet and mobile communication. As these drivers have come together to create the mobile Internet, mobile operator business models have rapidly evolved to address the opportunity with enhanced communications.

Moving forward, this evolution is now generating not one but three major disruptions in the industry - mobile broadband speeds, consumer-friendly billing plans and multimedia device usability - which combined will result in a traffic tidal wave that requires a true next-generation multimedia core network.

These drivers are fueling data traffic usage beyond expectations and placing unprecedented pressure on the packet core network. Today's non-HSPA packet core networks are designed to handle EDGE and WCDMA services that peaked at 384 kbps.

However, with the multi megabit performance of HSPA and growing subscriber base, the packet core network must become a multimedia core that is designed for this increasing demand. The packet core network must change drastically to provide the intelligence, performance and scale required for HSPA mobile broadband with always-on services - not to mention to be ready for LTE.

Disruptions in detail

Before going further, it's worth looking at the above disruptions in a little more detail.

The mobile world is moving from hundreds of kbps to multi-megabits rates well ahead of the mass market commercialization of LTE. The multi-megabit rates include both downstream and upstream bandwidth as the mobile Internet is migrating from email and basic Internet access to mobile TV, video on demand and advanced gaming services.

As a result, the evolution of EDGE/WCDMA networks to HSPA, HSPA+ and LTE is a major technology disruption offering speeds to mobile devices from 3 Mbps to 14Mbps today with HSPA, 28-42Mbps with HSPA+, and finally well over 100 Mbps with LTE. The average traffic per subscriber is expected to grow dramatically for each of the technologies.

While WCDMA is expected to provide 2x the average traffic per subscriber compared with EDGE, HSPA is expected to see average traffic per subscriber increases of 6x to 14x in contrast to EDGE. As services become richer and more varied, the core network becomes increasingly strategic for service providers as they shift from a communications-centric to communications and media centric solution.

Combine this increase of traffic and services with the large growth in subscriber numbers, and it is clear the packet core network is about to see a tidal wave of demand. If the right packet core is not in place for HSPA, trouble is ahead.

The introduction of flat rate data plans is a market disruption that has increased the consumption and variety of data services. With flat rate plans, users do not have to constantly monitor usage, allowing them more freedom to use new innovative services that will consume the mobile broadband bandwidth. The impact of flat rate billing is that usage patterns immediately change, and the network must be prepared to address unprecedented pressure on the packet core network.

The market disruption with potentially the greatest influence on stimulating traffic growth is improved usability of mobile devices and services. Users now have devices that make it significantly easier to access content and applications on the network.

This has shown to be a major market disruption on the network and has opened a crack in the flood gates of mobile Internet demand. The recently introduced multimedia devices are merely the start of the trend as all phones, laptops and other emerging mobile devices will dominate the market in the years to come.

The combination of new easy-to-use multimedia devices, a promise of mobile broadband connectivity, and a wide array of multimedia services is accelerating demand for HSPA networks. The projected number of worldwide HSPA subscribers is expected to surpass 600 million over the next five years and traffic growth will be an order of magnitude higher. HSPA moves from a minor portion of the network to the dominating technology for multimedia core networks. 

However, today's non-HSPA packet core networks are designed to handle EDGE and WCDMA services that peaked at 384 kbps. 

HSPA-optimized elements

One scaling option is to continually "stack" additional 2G/2.5G platforms. While providing a temporary band-aid, this option makes the network more complex and expensive and provides inferior "just good enough" performance, all the while not addressing long-term network needs. While stacking may work for traffic growth of 2x or 3x, what happens when this is off by an order of magnitude?

Using non-HSPA-optimized elements prevents operators from lowering the cost per byte/session as the network scales. The signaling and performance limitations of such platforms cause additional platforms to be 'stacked' before any savings can be realized. Just when the point arrives to start realizing cost savings, a new platform is required.

The enormous projected growth of traffic for HSPA and LTE requires a platform optimized for high bandwidth data services. There is an emerging traffic, cost and revenue challenge in the industry. Traffic is increasing at a rate larger than revenue. To maximize profit, operators must look at HSPA and LTE products and technologies that lower the cost of the network as traffic grows.

For service providers, making the wrong choice in HSPA infrastructure equipment will limit LTE deployment options. The HSPA platform must be designed to scale from HSPA to HSPA+ to LTE or directly from HSPA to LTE.

A tidal wave of data traffic is about to hit packet core networks across Asia and around the world. The question is how ready they are for 20x, 30x or even 50x leaps in packet traffic. A next-generation multimedia core platform is required to optimize the profitability as networks migrate to HSPA and eventually to LTE. It is very important to select a next-generation platform for HSPA to meet subscriber expectations and network demand. The same platform must evolve to support LTE without changing out or introducing new hardware.

The bottom line for today's WCDMA operators is this: you cannot wait for the deployment of LTE radios to evolve the packet core. The decision for the LTE Evolved Packet Core (EPC) network is today. It is the HSPA decision.

Jonathan Morgan is senior director of product marketing for Starent Networks