Using newly licensed and existing spectrum the highest 4G speeds will be achieved by the very latest devices which are LTE Advance LTE Category 6 capable. These devices can achieve peak download speeds of 300 Mbps by carrier aggregation of two 20 MHz carriers. Such devices as the just announced Samsung Galaxy Note 4 use the Qualcomm Snapdragon 805 system on a chip SoC in combination with the latest modem family Gobi 9×35. Otherwise customers with Category 4 phones which have LTE Band 28 700MHz capability such as Samsung Galaxy S5 and Desire 610, HTC One M8 and LG G3 (equipped with older Qualcomm Snapdragon 801 and Gobi 9×25 chips) will be able to achieve up to 150 Mbps using a 20 MHz carrier or by aggregating two 10MHz carriers. The newly announced iPhone 6 and 6 Plus are also only Category 4 (150Mbps) capable but they do cover all currently used and planned LTE bands including Optus’ 2300MHz TDD LTE in their 20 LTE band repertoire.
There are grand plans for ever increasing carrier aggregation capability built into, and being developed for, the LTE standard. The Qualcomm diagram below shows the possibilities of combining spectrum from different LTE bands, both FDD and TDD, and both licensed and unlicensed spectrum as well as “Multiflow” combining data streams from multiple base stations to achieve faster speeds and greater capacity.
In December 2013 Optus upped the ante in the aggregation speed stakes demonstrating 520Mbps using 4X20MHz of its 2.3GHz TDD LTE spectrum at St Marys Sydney. Optus was using Huawei network kit. In May 2014 Telstra demonstrated 450Mbps using three LTE channels however in June 2014 Nokia and SKT trumped everyone and announced trials in which they achieved 3.8Gbps by aggregating 10X20MHz channels combining TDD and FDD LTE. This is twice the number of carriers (5X20MHz) which 3GPP foresees being used. No doubt this will change with the relentless desire for increased speed and capacity.
The speed race can only get more interesting (and complex) from here.
