Next-generation mobile networks in Asia are performing impressively out of the gate, but their success reflects network design as much as air interface achievements, according to Signals Research Group, which recently drive tested TD-LTE in Tokyo and LTE Advanced over an FDD network in Seoul.
Click here for a larger view.
The company achieved a peak downlink data rate of 92.3 Mbps on SoftBank's TD-LTE network in Japan. Even more impressive was the blazing peak downlink data rate of 141.0 Mbps on an LTE Advanced carrier aggregated network operated by an unspecified South Korean mobile carrier. SK Telecom, LG U+ and Korea Telecom have all launched LTE Advanced carrier aggregation.
So will U.S. operators see such dramatic speeds when they roll out LTE Advanced carrier aggregation? Probably not, because South Korean and U.S. mobile network designs are dissimilar. For one thing, South Koreans have built out mobile networks with very high cell site density.
"There may be thousands and thousands of users in Korea, but you've also got hundreds and hundreds of cells vs. in the U.S. where you have tens and tens of cells," Michael Thelander, CEO of Signals Research, told FierceBroadbandWireless.
"When it comes to carrier aggregation in the U.S., whatever speed you're getting today, you'll basically double it," he said.
Because the Japanese and South Korean LTE networks use different frequency bands and channel bandwidths and because the geographic size of the test areas in the two countries differed, Thelander also said it is not fair to directly compare results gleaned from the two networks.
He noted the recent Asian speed tests used the Accuver XCAL drive test solution and XCAP post-processing software. Extensive testing over a multi-day period was performed using typical user applications, such as VoLTE, Skype, video telephony, 1080p video streaming and more.
Signals Research tested SoftBank's TD-LTE and LTE FDD networks in Japan using two test USIMs supplied by the operator and access to a high-bandwidth FTP server that was used for testing purposes. The research firm also used a Qualcomm (NASDAQ:QCOM) test platform with a form factor comparable to that of a commercial device.
SoftBank has deployed a 1 x 20 MHz channel of TD-LTE in Band 41, where the center frequency is 2565 MHz. "We observed an average downlink data rate of 31.3 Mbps and a peak downlink data rate of 92.3 Mbps in the SoftBank LTE TDD network while concurrently testing the operator's FDD network," Thelander said.
Signals Research tested LTE Advanced Release 10 carrier aggregation in Seoul, leveraging 2 x 10 MHz carriers with multiple devices. The firm also had access to a high-bandwidth FTP server in the country and augmented that server with a second FTP server located outside of the country and a UDP server located in North America.
In Seoul, the company bought an LG G2 smartphone that supports carrier aggregation and an LG Optimus smartphone that was limited to LTE Release 8 capabilities. Both smartphones came with service contracts. The research firm also rented two LTE smartphones to take advantage of the USIMs, which offered unlimited daily usage.
Signals Research recorded an average downlink data rate of 62.0 Mbps and a peak downlink data rate of 141.0 Mbps during the LTE Advanced carrier aggregation testing in Seoul.
"Based on our preliminary analysis and observations while collecting the data, we believe that both networks are capable of achieving even higher average throughput based on currently implemented technologies," said the firm's report.
- see the Signals Research website
Huawei, Turkcell demo 900 Mbps LTE Advanced performance
NTT DoCoMo gears up for 150 Mbps LTE service
Sprint adds Clearwire's 2.5 GHz band to LTE coverage area
SK Telecom: Take a closer look at its LTE Advanced rollout
LTE Advanced is the next competitive battleground for operators
Macrocells struggle to deliver indoor coverage