HSPA (high-speed packet access) and MBMS (multimedia broadcast and multicast service) bring important capability enhancements to W-CDMA. However, they do not match broadcasting technologies (such as DVB-H) or broadband wireless access (such as WiMAX) for delivering mobile TV, Internet access and other important services. 3G may need a major leap forward in capabilities to remain competitive. The relatively little-known 3G LTE (Long-Term Evolution) standard, often termed ‘Super 3G’, may provide the necessary breakthrough, to support a range of new services from 2009.

By adopting many of the same techniques as alternative wireless technologies, such as WiMAX, 3G LTE is aiming to achieve a peak downlink data rate of 100Mbit/s, an increase in capacity of three to five times compared to HSPA (in the same bandwidth) and latency as low as 20ms. While its performance in a real network implementation remains to be seen, such capabilities have the potential to enable some significant new service opportunities.

Fixed-mobile substitution, when customers cease using fixed voice services altogether, is a great opportunity for mobile-only operators. However, the need to be competitive with DSL, in terms of performance and pricing, places great demands on wireless technology. HSPA does not achieve the capacity, latency or cost per Mbyte needed to compete head-on with fixed DSL services. But according to report co-author Mark Heath, “3G LTE could bring the step change needed for mobile operators to offer a realistic alternative to fixed services."

Mobile TV and video are increasingly seen by mobile operators as ‘must have’ services. However, by the time the majority of users have migrated to 3G networks, HSPA will only be able to support a few minutes of unicast viewing per day. Moreover, within the confines of current 3G paired-frequency allocations, the MBMS broadcasting capability will only support a small number of channels compared to DVB-H.But, as Mark Heath points out, “3G LTE could enable mobile operators to offer an attractive mix of broadcast and unicast content without needing DVB-H."

The advent of 3G LTE could also make cellular VoIP (voice over IP) commercially viable for the first time. VoIP could bring major benefits for mobile operators, including cost savings and the ability to integrate voice and multimedia services. “While there is insufficient rationale for using VoIP over HSPA, due to IP overheads, there may be a compelling case with 3G LTE," says Heath.

Although 3G LTE could revolutionise the capabilities of 3G networks, there are some important challenges to overcome. According to report co-author Alastair Brydon, “The full benefits of 3G LTE will only be achieved if mobile operators are able to use it in 20MHz of bandwidth, which will require new spectrum allocations." This means that mobile operators will need to secure additional spectrum, such as the GSM extension band, and ensure that other technologies or new entrants do not get access to this valuable spectrum. “While 3G LTE is being designed to minimise the cost of upgrades for mobile networks, there are still great uncertainties over the investments that operators will need to make, in terms of network infrastructure and spectrum," says Brydon. The 3G community will need to address these uncertainties quickly if it is to build momentum in 3G LTE.

Prospects for the Evolution of 3G and 4G studies the options for the evolution of 3G networks, focusing on the forthcoming 3G LTE and 4G standards. It evaluates the realistic capabilities of 3G LTE in terms of throughput, capacity, latency and cost per Mbyte. By modelling a typical network, it quantifies the practical gains that will be achieved by 3G LTE and the service mixes that it will be able to support. The report identifies actions to enable mobile network operators and equipment vendors to seize the opportunities that the evolution of 3G networks will provide. www.analysys.com