A Study of PDCP Reorder Time in Dual Connectivity in Multiple Wireless Heterogeneous Base Stations

Author(s):  
Young-Gyun Kim ◽  
Sang-Hyo Kim
2021 ◽  
Author(s):  
Yoghitha Ramamoorthi ◽  
Masashi Iwabuchi ◽  
Tomoki Murakami ◽  
Tomoaki Ogawa ◽  
Yasushi Takatori

<p>The next generation 6G wireless systems are envisioned to have higher reliability and capacity than the existing cellular systems. The reconfigurable intelligent surfaces (RISs) is one of the promising solution to control the wireless channel by altering the electromagnetic properties of the signal. The dual connectivity (DC) increases the per-user throughput by utilizing radio resources from two different base stations. In this work, we propose the RIS assisted DC system to improve the per-user throughput of the users by utilizing resources from two base stations (BSs) in proximity via different RISs. Given an fairness based utility function, the joint resource allocation and the user scheduling of RIS assisted DC system is formulated as an optimization problem and the optimal user scheduling time fraction is derived. The heuristic is proposed to solve the formulated optimization problem with the derived optimal scheduling time fractions. The exhaustive simulation results for coverage and throughput of the RIS assisted DC system are presented with varying user, BS, blockage, and RIS densities for different fairness values. Further, we show that the proposed RIS assisted DC system provides significant throughput gain of 52% and 48% in certain scenarios when compared to the existing benchmark and DC systems.</p>


2021 ◽  
Author(s):  
Yoghitha Ramamoorthi ◽  
Masashi Iwabuchi ◽  
Tomoki Murakami ◽  
Tomoaki Ogawa ◽  
Yasushi Takatori

<p>The next generation 6G wireless systems are envisioned to have higher reliability and capacity than the existing cellular systems. The reconfigurable intelligent surfaces (RISs) is one of the promising solution to control the wireless channel by altering the electromagnetic properties of the signal. The dual connectivity (DC) increases the per-user throughput by utilizing radio resources from two different base stations. In this work, we propose the RIS assisted DC system to improve the per-user throughput of the users by utilizing resources from two base stations (BSs) in proximity via different RISs. Given an fairness based utility function, the joint resource allocation and the user scheduling of RIS assisted DC system is formulated as an optimization problem and the optimal user scheduling time fraction is derived. The heuristic is proposed to solve the formulated optimization problem with the derived optimal scheduling time fractions. The exhaustive simulation results for coverage and throughput of the RIS assisted DC system are presented with varying user, BS, blockage, and RIS densities for different fairness values. Further, we show that the proposed RIS assisted DC system provides significant throughput gain of 52% and 48% in certain scenarios when compared to the existing benchmark and DC systems.</p>


2019 ◽  
Vol 9 (15) ◽  
pp. 3018 ◽  
Author(s):  
Ren-Hung Hwang ◽  
Min-Chun Peng ◽  
Kai-Chung Cheng

Dual connectivity (DC) was first proposed in 3GPP Release 12 which allows one piece of user equipment (UE) to connect to two base stations in heterogeneous networks (HetNet) at the same time, to increase the flexibility of resource utilization. DC has been further extended to multiple connectivity in 5G New Radio (NR). On the other hand, different UE tends to have different bandwidth requirements. Thus, in DC, one of the challenging issues is how to integrate resources from two base stations to enhance the quality of service (QoS) as well as the data transfer rate of each UE. In this paper, we proposed novel resource management mechanisms to improve the QoS of UE in the co-channel dual connectivity network. In terms of resource allocation, we designed the (MTS) which, in principle, allocates a resource block to the UE with the best channel quality while considering the issues of intercell resource allocation and the QoS requirement of each UE. In order to balance the load of different cells, we designed a novel cell selection scheme based on the HetNet Congestion Indicator (HCI) which considers not only the signal quality of UE but also the remaining resources of each base station. To improve the QoS of cell edge UE, cell range expansion (CRE) and the Almost Blank Subframe (ABS) were proposed in 3GPP. In this paper, based on Q-learning, we designed an adaptive mechanism which dynamically adjusts the ABS ratio according to the network condition to improve resource utilization. Our simulation results showed that our MTS scheduler was able to achieve a 31.44% higher data rate than the Proportional Fairness Scheduler; our HCI cell selection scheme yielded a 2.98% higher data rate than the signal-to-interference plus noise ratio (SINR) cell selection scheme; the QoS satisfaction rate of our Q-learning dynamic ABS scheme was 4.06% higher than that of the Static ABS scheme. Finally, for the cell edge users who often suffer poor data transfer rate, by integrating the mechanisms of DC, CRE, and ABS, our experimental results showed that the QoS satisfaction ratio of cell edge UEs could be improved by 10.76% as compared to the single connectivity and no ABS situation.


2020 ◽  
Vol 99 (4) ◽  
pp. 344-350
Author(s):  
Evgeny V. Zibarev ◽  
A. S. Afanasev ◽  
O. V. Slusareva ◽  
T. I. Muragimov ◽  
V. A. Stepanets ◽  
...  

In recent years, in the Russian Federation there has been an increase in the levels of radiofrequency electromagnetic fields in residential areas, including due to an increase in the number of base stations (BS). The purpose of sanitary and epidemiological surveillance at the stages of placement and commissioning of base stations (BS) is to prevent their adverse effects on public health. The increase in the number of base stations, together with the advent of new electronic equipment and antennas, provide opportunities for improving the processes of their accounting at the stage of placement and monitoring of the levels of radiofrequency electromagnetic fields at the operation stage. This automation tool can be a geo-information portal for providing sanitary and epidemiological surveillance of cellular base stations. The prototype of the geo-information portal allows both calculating the size of sanitary protection zones (SPZ) and building restriction zones (RZ) from the BS in online mode, displaying the results of calculations in graphical form and issuing sanitary and epidemiological conclusions for the placement and operation of base stations. The geo-information portal has the ability to synchronize with the data of the radio frequency center. Federal Service for Surveillance on Consumer Rights Protection and Human Wellbeing will be able to receive up-to-date analytical data. There will be completely automated processes of collecting, processing and storing information on BS.


2020 ◽  
Vol E103.B (7) ◽  
pp. 796-803
Author(s):  
Junyao RAN ◽  
Youhua FU ◽  
Hairong WANG ◽  
Chen LIU

Author(s):  
Natalya Ivanovna Shaposhnikova ◽  
Alexander Aleksandrovich Sorokin

The article consideres the problems of determining the need to modernize the base stations of the cellular network based on the mathematical apparatus of the theory of fuzzy sets. To improve the quality of telecommunications services the operators should send significant funding for upgrading the equipment of base stations. Modernization can improve and extend the functions of base stations to provide cellular communication, increase the reliability of the base station in operation and the functionality of its individual elements, and reduce the cost of maintenance and repair when working on a cellular network. The complexity in collecting information about the equipment condition is determined by a large number of factors that affect its operation, as well as the imperfection of obtaining and processing the information received. For a comprehensive assessment of the need for modernization, it is necessary to take into account a number of indicators. In the structure of indicators of the need for modernization, there were introduced the parameters reflecting both the degree of aging and obsolescence(the technical gap and the backlog in connection with the emergence of new technologies and standards). In the process of a problem solving, the basic stages of decision-making on modernization have been allocated. Decision-making on the need for modernization is based not only on measuring information that takes into account the decision-makers, but also on linguistic and verbal information. Therefore, to determine the need for upgrading the base stations, the theory of fuzzy sets is used, with the help of which experts can be attracted to this issue. They will be able to formulate additional fuzzy judgments that help to take into account not only measuring characteristics, but also poorly formalized fuzzy information. To do this, the main indicators of the modernization need have been defined, and fuzzy estimates of the need for modernization for all indicators and a set of indicators reflecting the need for upgrading the base stations have been formulated.


Sign in / Sign up

Export Citation Format

Share Document