ITU Approves "LTE Advanced"

The Computer World article LTE-Advanced is the future, but no rocket ship reported that the ITU gave its approval to two new standards--LTE-Advanced and WirelessMAN-Advanced at the ITU Radiocommunication Assembly in Geneva last Wednesday. The article said carriers may start implementing LTE-Advanced later this year.

LTE-Advanced allows carrier aggregation, the technology AT&T will use to move downlink traffic to the spectrum that it is buying from Qualcomm. The FCC prohibited AT&T from using that spectrum for uplink (mobile/portable device to base station) communications. LTE-Advanced also allows the use of four or more antennas to improve MIMO (multiple input/multiple output) performance. LTE currently uses only two antennas per device. Due to the need to isolate the antennas, this may not be practical for cell phones but could work well for high-speed in-car communications. Other improvements include "heterogeneous networking", which the Computer World article said includes mechanisms "to make conventional macro cells work better with the smaller cells now being developed to better serve crowded and indoor areas." The article cautions that these improvements, however, are unlikely to lead to any significant increase in speed, even though there is potential for a true 100 Mbps mobile service if carriers wanted to build it.

Rethink-Wireless writer Caroline Gabriel reported Dish Network plans to go straight to LTE-Advanced when it starts building a terrestrial network using its mobile satellite spectrum, assuming the FCC grants a waiver for it to run terrestrial-only services in a band allocated for mobile satellite.

I have not had time to review the LTE-Advanced technology, but it appears these changes will make it easier to implement the "Broadcast-Overlay" next-generation TV standard and to dynamically share spectrum with wireless broadband. Carrier aggregation is a key part of this and the ability to use four or more antennas to achieve higher data rates or more reliable service, while not practical for hand-held devices, could make it easier to offer high definition services using an LTE-Advanced based broadcast-overlay to larger screens.

Doug Lung is one of America's foremost authorities on broadcast RF technology. He has been with NBC since 1985 and is currently vice president of broadcast technology for NBC/Telemundo stations.