Interessant artikel van Qualcomm over de toekomst van LTE (Advanced) en de toepasbaarheid daarvan, oa mbv het combineren van de diverse frequentie zoals bijv. van micro/femto cells voor het vergroten van de bandbreedte door middel van Carrier Aggregation.
LTE Advanced brings multiple dimensions of enhancements including leveraging wider bandwidth, more antennas and heterogeneous networks (HetNets), all of which are crucial to address the looming 1000x mobile data challenge. Carrier aggregation is the first step in LTE Advanced commercialization, offering increased user data rates for all users in the cell. The higher data rates can also be traded off to offer increased capacity for bursty applications such as web browsing. Carrier aggregation continues evolve into various directions including more carriers (up to 5 carriers and up to 100MHz supported in standards), across FDD and TDD, across cells and more.
First with carrier aggregation
More carriers means more speed across the cell
Can double capacity for bursty applications
The increased data rates of carrier aggregation can be traded off to get twice or more capacity for bursty applications, while maintaining the same user experience, under typical network loading conditions. As evident, when carriers are aggregated, there are more resources, but due to trunking efficiency the overall capacity can be much more than the sum total of the capacity of the individual carriers. The increased capacity will help operators to address bursty smartphone traffic as well as increased use of social media applications, instant messaging and others.
Utilizing all spectrum resources
Generally, the available spectrum in most parts of the world is fragmented. Carrier aggregation is a glue that binds them together to offer wider bandwidths, while enabling utilization of all the available spectrum. Carrier aggregation allows combining lower and higher bands— leveraging better coverage of the former with higher availability of the latter. Supplemental Down Link (SDL) allows combining paired and unpaired spectrum to boost down link capacity. Similarly, carrier aggregation allows HetNets to make best use of spectrum, e.g. higher bands for small cell (3.5 GHz) and lower bands (700 MHz) for macros.
Carrier aggregation continues to evolve
The current aggregation of two 10 MHz carriers is only the beginning. It will evolve in many directions. In the near term, there could be aggregation across more carriers—up to five defined in LTE Advanced—and more band combinations—more than 45 being defined in 3GPP; aggregation in the uplink etc. There is currently work going on to facilitate aggregation across cells on the same carrier for load balancing, called MultiFlow; aggregation across paired and unpaired spectrum (LTE FDD and TDD) and many more.
Meer informatie: Presentatie Qualcomm over LTE Advanced