Satoshi Nagata

Licensed-Assisted Access to Unlicensed Spectrum in LTE Release 13

Exploiting the unlicensed spectrum is considered by 3GPP as one promising solution to meet ever-increasing traffic growth. As a result, one major enhancement for LTE in Release 13 has been to enable its operation in the unlicensed spectrum via licensed-assisted access (LAA). In this article, we provide an overview of the Release 13 LAA technology including motivation, use cases, LTE enhancements for enabling the unlicensed band operation, and the coexistence evaluation results contributed by 3GPP participants.

LTE-advanced pro: part 1 [Guest Editorial]

The mobile Internet that will be enabled by LTE-Advanced Pro and the way in which we interact with it will change significantly within the next few years. From a usage point of view, it is anticipated that by 2020, each person, globally speaking, will consume on average as much as 5 GB of data each month, in addition to the traffic generated by 20-30 billion connected things. More significantly, not only will the mobile network be significantly faster, but even more applications will become possible. The video experience will be improved globally; mobile virtual reality will be available; networked vehicles and perhaps self-driving cars will roam our streets; the Internet of Things will enrich and make our lives more productive; and a mobile cloud will allow access to our data anytime, anywhere.

LTE-advanced pro: Part 1

Long Term Evolution (LTE) has become the most successful mobile wireless broadband technology, serving over one billion users as of the beginning of 2016. However, looking at the penetration rate, LTE serves only 14.5 percent of the current 7.3 billion mobile subscriptions. Consequently, there is still significant room for LTE to grow as a mobile technology; it will be serving users for a long time to come.

Prediction and validation of propagation loss in urban micro-cell environment by using ray tracing simulation

Field test and ray tracing (RT) simulation results for an adaptive array antenna (AAA) for micro-cell environments in central Tokyo area, is presented. The radio frequency was 3.35 GHz. The AAA at the base station was installed at the height below the buildings, i.e. microcell environment was considered. The AAA element spacing was set to be eight wave-length for space diversity. The height of a transmitter antenna at a mobile was 2 m. The distance ranged from 30 to 100 m between the receiver and transmitter antennas. Propagation characteristic measurements show that maximum delay time is less than 0.5-symbol period and averaged delay spread throughout the course is less than 0.05/spl mu/ sec. So the channel is regarded as frequency-flat. RT simulation results are compared with measured ones with respect to the received power at the AAA. The RT simulation results provide good approximation in line-of-sight (LOS) sections and slightly shadowed non-line-of-sight (NLOS). Contrary, in deeply shadowed NLOS area, it gives a large error.