NEW YORK — Nokia announced upgraded base stations that let operators migrate WiMax networks to TD-LTE Advanced. The company’s 3.5 GHz carrier aggregation-capable system aims to smooth the transition to more advanced networks as well as improve service in dense user environments.
“There are still operators with WiMax [Worldwide Interoperability for Microwave Access] operation... stuck in a spectral efficiency dimension, which will not evolve. TD-LTE will accommodate more traffic and more users in the same amount of spectrum,” Arne Schaelicke, Nokia’s LTE marketing manager, told EE Times. “This would allow for four times more traffic flow, with carrier aggregation and higher MIMO schemes.”
Nokia’s Flexi Multiradio 10 Base Station has integrated WiFi for reducing network interference and power consumption. The 3.5 GHz LTE band -- allocated in approximately 70 countries -- lets operators free up to 200 MHz of spectrum for additional capacity, according to the company release.
Improved spectral efficiency will allow for improvements in download and upload speeds. Using 20 MHz, TD-LTE can carry 110 Mbit/s peak on a dowlink. Downlink on a network with carrier aggregation is 330 Mbit/s peak.
Schaelicke said Nokia hopes to go beyond 330 Mbit/s data rates, which the company demonstrated at Mobile World Congress 2014. At MWC, Nokia achieved peak data rates of up to 450 Mbit/s with up to 60 MHz of spectrum on its Flexi Multiradio 10 Base Station.
Nokia's carrier aggregation software selects the best carriers in the network appropriate for each user. A Nokia blog outlined a situation where a Category 6 device capable of supporting aggregation of two carriers at up to 40 MHz was used in a network featuring three carriers aggregating up to 60 MHz. Nokia’s network software allocated the two best carriers to “add network capacity by freeing-up the 20 MHz bandwidth not allocated to this device to those users who can benefit from that frequency.”
The software also support load balancing, which will increase in importance as LTE networks take on growing amounts of video traffic and additional users.
The TD-LTE radio and associated software was announced alongside the Flexi Metro Remote Radio Head (RRH) with 60 MHz carrier aggregation for dense networks. Officials at Nokia said the RRH’s small volume at less than 5 liters and less than 5 kg weight will allow operators to take advantage of a wide range of sites typically unsuitable for conventional units. Additionally, the RRH’s sensitivity can be tuned and output varied from 2x5 W down to 2x50 mW to meet the needs of different networks.
“Operators are making their networks more dense by splitting macro cells or adding more network layers for the vital extra capacity needed especially in metropolitan areas,” Thorsten Robrecht, vice president of Mobile Broadband portfolio management at Nokia Networks, said in the press release. “As the distance between cells decreases and network layers increase, mobile devices cause greater interference,” an issue Nokia's product mitigates, he claims.
The low-power radio enables Nokia and operators to connect a variety of dense areas that are laden with fiber optics as well as small-cell networks without fiber, Stephane Daeuble, Nokia's marketing manager for Small Cells/HetNet, told EE Times.
“We’re preparing for the commercial introduction of Cat 9 smartphones or user devices, which can support carrier aggregation up to 60 MHz,” Schaelicke said. “We expect smartphones to be able to support this next year, but we need to prepare the network.”
— Jessica Lipsky, Associate Editor, EE Times