A rising number of mobile operators are touting LTE-Advanced progress, some in real networks, like SK Telecom’s, some in field tests, like Turkcell’s which reported peak speeds of 900Mbps approaching the 1Gbps which is the official definition of ‘4G’. Even the most advanced LTE-A deployer, as we have discussed before, is implementing more than a small subset of the huge menu of options included in Release 10 and 11 of the 3GPP standards, with the focus heavily on carrier aggregation, and with eICIC (for HetNets) and advanced MIMO also popular early choices. However, while LTE-A will remain a small part of the commercial 4G landscape for a couple of years, confined to the most cutting edge and/or capacity-challenged cellcos, these moves are certainly moving the technology forward at a faster rate than was seen in previous generations.
While Release 10 is the current bedrock, LTE-A, as well as HSPA+, are further refined in Release 11, whose features were frozen in December 2012 (for the core network) and in March 2013 for the RAN.
For HSPA+, Rel-11 introduces new capabilities including eight-carrier downlink operation; downlink 4-branch MIMO to double maximum theoretical downlink rates to 336Mbps; downlink multiflow transmission; uplink dual-antenna beamforming; uplink MIMO with 64QAM; several CELL_FACH (Forward Access Channel) state enhancements (for smartphone type traffic); and non-contiguous HSDPA carrier aggregation.
For LTE, as outlined in a new white paper from the 4G Americas trade group, Rel-11 provides enhancements to Release 10 technologies such as carrier aggregation; MBMS; self-organizing networks (SON); CoMP for coordinated scheduling and/or beamforming and better cell edge performance; enhanced Physical Downlink Control Channel (EPDCCH); and further enhanced enhanced Inter-Cell Interference Coordination (FeICIC) for devices with interference cancellation.
Release 11 also looks beyond phones and beyond the 3GPP technologies by addressing machine communications, IMS and Wi-Fi integration, plus enhanced support for femtocells (Home NodeB and Home e-Node B).
Chris Pearson, president of 4G Americas, said in a statement: ‘The technical evolution of LTE, teamed with more spectrum and innovative regulatory policies, will go a long way in meeting the difficult mobile broadband demand challenge that society has placed on wireless carriers.’
Progress in standards gives the mass of operators the confidence to migrate to LTE-A, in a way that advanced, and often semi-proprietary, early mover deployments do not. However, more carriers are joining the LTE-A race, trailing in the wake of first mover SK Telecom of Korea, which has now expanded its carrier aggregation-enabled services to the downtown areas of 84 cities, working with Ericsson.
But SK’s 150Mbps speeds could be dwarfed if Turkcell brings its latest technology to market. So far confined to labs, the approach delivers a peak of 900Mbps, said CEO Sureyya Ciliv, using Huawei kit. He told a conference: ‘Last year, we doubled our mobile internet speed by renewing our 3G network with dual-carrier technology and ensured a speed of up to 43.2Mbps. In the tests carried out today, the indicator reached approximately 900Mbps, which set a new record for Turkey.’ Turkcell conducted the ‘the first LTE test of Turkey’ in collaboration with Ericsson in 2009, reaching a speed of 170Mbps in the lab environment.
Another carrier which is always pushing the limits in terms of wireless speeds is Telstra of Australia, whose latest move is to deploy carrier aggregation across its 900MHz and 1.8GHz bands, working with Ericsson on the first CA deployment to use this combination of frequencies (both refarmed from 2G). The test was completed in a commercial network in Queensland and Mike Wright, the operator’s executive director of networks, commented: ‘The capacity, higher data speeds and efficiencies provided by LTE-A will help manage growth in data traffic as more customers choose our network. This will allow us to continue providing additional capacity and high-quality service ‘ When we get access to 700MHz spectrum in 2015 we also intend to deploy the next-generation of LTE-A by combining larger blocks of spectrum in the 700MHz and 1.8GHz bands to deliver blistering peak speeds in the theoretical range of 300Mbps.’
Finally, Smart of the Philippines has become the latest Asian operator to test LTE-A, as European cellcos appear to lag behind (though they have the kind of broad swathes of spectrum, often in the standardized bands of 2.6GHz, 1.8GHz or 800MHz, which will enable them to access mainstream devices as these become available, and to deliver the higher speeds enabled by CA quickly and at relatively low cost when they need to.
Smart, the mobile unit of Philippines telco PLDT, is working with Huawei on its trials and has already achieved downlink speeds of 209Mbps in the lab.