Commercial LTE Research Articles

LTE enhancements for public safety and security communications to support group multimedia communications

Currently public safety and security communication systems depend on reliable and secure PMR networks that are mainly devoted to provide voice services. However, the evolutionary trend for professional mobile radio (PMR) networks is toward the provision of new value-added multimedia services such as video streaming, in order to improve situational awareness and enhance life-saving operations. The challenge here is to exploit the future commercial broadband networks to deliver voice and multimedia services satisfying PMR service requirements. In particular, a viable solution now seems to be the adaption of the new Long Term Evolution technology to provide IP-based broadband services with the security and reliability typical of PMR networks. This article outlines different alternatives to achieve this goal and, in particular, proposes a proper solution for providing multimedia services with PMR standards over commercial LTE networks.

LTE-R의 도시철도 터널 환경 적용성 분석

Unlike commercial LTE network, LTE-R railway network is arranged along a railroad track and the base stations of the network (RUs) are also installed on the waysides. For urban railway systems that are composed of underground tunnels, the leakage coaxial cables are widely used due to the radio propagation characteristics in tunnels. In theory, the tunnel sections are interpreted as the waveguide with blank spaces and for this reason, the tunnel sections are expected to be better than open ground sections in terms of the radio propagation characteristics. In this paper, we analyze the radio propagation characteristics based on this theory by replacing the leakage coaxial cables in the network with Yagi antennas. The test has been carried out in the 2.2km tunnel in the Daebul test track of KORAIL with 2.6GHz LTE-R Network. The LTE-R applicability in urban railways has been tested through the analysis on the radio propagation characteristics with the unmanned train operation system in Daebul tunnel.

Demonstration of digital fronthaul over self-seeded WDM-PON in commercial LTE environment.

CPRI between BBU and RRU equipment is carried by self-seeded WDM-PON prototype system within commercial LTE end-to-end environment. Delay and jitter meets CPRI requirements while services demonstrated show the same performance as bare fiber.

LTE 이동통신 시스템의 처리율과 무선 채널 상태와의 상관관계 분석

대표적인 4세대 이동통신 시스템으로서 LTE는 과거 이동통신 시스템에 비하여 훨씬 더 높은 전송 속도를 제공한다. 그러나 무선 환경의 특성 상 LTE가 제공하는 전송 속도는 무선 채널의 상태에 따라서 큰 영향을 받을 수 있다. LTE 시스템의 무선 접속을 통해서 제공되는 대부분의 서비스에 대한 사용자의 만족도는 전송속도에 일차적인 영향을 받게 된다. 따라서 본 논문에서는 무선 채널의 상태를 대표하는 다양한 품질 지표를 선정하고 이들에 대한 실체 측정을 실시하여 각 품질 지표의 변화에 대한 LTE 시스템의 전송 속도의 변화를 관찰하였다. 그 결과 채널의 상태가 나빠질수록 신호의 세기가 아닌 신호의 품질이 LTE 시스템이 제공하는 전송 속도에 밀접한 영향을 미친다는 사실을 알 수 있었다. As a representative system of the 4th generation mobile communication system, LTE provides much higher transmission rate than the former ones. Considering the varying property that a wireless environment shows, the transmission rate is influenced very deeply by the wireless channel conditions. The transmission rate is one of the most important attributes that has a primary effect on user's satisfaction of the service provided through the LTE system. After we have selected a few metrics that indicate the wireless channel quality, therefore, we have conducted a measurement for the metrics over the real commercial LTE system. By analyzing the measured results, we have found that the channel quality affect more on the transmission rate as the channel quality becomes poorer.

Interference Analysis of LTE Network and RF Optimization

The reasons interfering LTE network are analyzed. Combining with the actual data of existing commercial LTE network, RF optimization scheme of LTE network to suppress the interference is promoted. According to the data released by road test, the proposed RF optimization scheme can improve the network coverage and network performance, and can play a reference role to other similar cases.

Networks and devices for the 5G era

Mobile services based on 4G LTE services are steadily expanding across global markets, providing subscribers with the type of responsive Internet browsing experience that previously was only possible on wired broadband connections. With more than 200 commercial LTE networks in operation as of August 2013 [1], LTE subscriptions are expected to exceed 1.3 billion by the end of 2018 [2]. LTE's rapid uptake, based on exponential growth in network data traffic, has opened the industry's eyes to an important reality: the mobile industry must deliver an economically sustainable capacity and performance growth strategy; one that offers increasingly better coverage and a superior user experience at lower cost than existing wireless systems, including LTE. This strategy will be based on a combination of network topology innovations and new terminal capabilities. Simple network economics also require that the industry's strategy enable new services, new applications, and ultimately new opportunities to monetize the user experience. To address these pressing requirements, many expert prognosticators are turning their attention to future mobile broadband technologies and standards (i.e., 5G) as well as evolutions of the 3GPP's existing LTE standard and IEEE 802.11 standards.

First LTE-Advanced Commercial Network Deployed [Mobile Radio

The Russian operator YOTA Networks and Huawei Technologies Company, Inc. announced the launch of what they claim is the world's first long-term-evolution-advanced (LTE-A) commercial network in Moscow. Huawei modernized its end-toend single radio-access network (RAN) LTE/Evolved Packet Core solution for LTE-A [in terms of 3rd Generation Partnership Project (3GPP) rev10]. The solution features carrier aggregation technology, which provides downlink peak rates of up to 300 Mb/s, depending on the capacity of the radio channel. Huawei also announced that it has successfully conducted what it claims is the world's first LTE-A uplink coordinated multipoint (CoMP) trial on several commercial LTE networks in Europe and Asia. The results showed that uplink CoMP can effectively double data rates at cell edges for a single user, improving network performance in terms of coverage, spectrum efficiency, and throughput.

Small-Size Triple-Wideband LTE/WWAN Tablet Device Antenna

A small-size tablet device antenna with three wide operating bands to cover the Long Term Evolution/Wireless Wide Area Network (LTE/WWAN) operation in the 698 ~ 960-, 1710 ~ 2690-, and 3400 ~ 3800-MHz bands is presented. The antenna has a planar structure and is easy to fabricate on one surface of a thin FR4 substrate of size 10×45×0.8 mm <sup xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">3</sup> . The antenna is formed by adding a first branch (branch 1, an inductively coupled strip) and a second branch (branch 2, a simple branch strip) to a coupled-fed shorted strip antenna (main portion), and the two branches are configured with the main portion to achieve a compact antenna structure. The three widebands are easy to adjust and can cover the LTE/WWAN operation, which includes the most commonly commercial LTE bands and WWAN bands (698 ~ 960 and 1710 ~ 2690 MHz) and the LTE 3.5-GHz band (3400 ~ 3800 MHz).

Threshold Receiver Model for Throughput of Wireless Devices With MIMO and Frequency Diversity Measured in Reverberation Chamber

We present a simple theoretical model for the throughput data rate of a wireless LTE device including the improvements of data rate due to diversity in frequency (OFDM) and spatial domains (MIMO) under frequency selective fading. The model is based on defining an ideal threshold receiver for the line-of-sight (LOS) case, corresponding to reception with advanced error-correcting codes. The theoretical throughput model is in agreement with measurements in a reverberation chamber of a commercial LTE device for the 1 × 2 SIMO case, both regarding diversity and MIMO array gains, and it can therefore be used to complement measured results in evaluation of performance of LTE devices.

First Commercial LTE Network [Mobile Radio

TeliaSonera has launched the first fourth-generation (4G) services commercially to customers in Stockholm, Sweden, and Oslo, Norway. TeliaSonera's current 4G networks cover the central city areas of Stockholm and Oslo. The Stockholm 4G city network is supplied by Ericsson, and the Oslo 4G city network is supplied by Huawei. The modems at launch come from Samsung. The 4G network roll-out will continue to Sweden's 25 largest municipalities and recreation areas and to Norway's four largest municipalities.