• Title/Summary/Keyword: mobile radio

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Interference and noise analysis for hybrid FSO/RF-based 6G mobile backhaul

  • Soyinka Nath;Shree Prakash Singh;Sujata Sengar
    • ETRI Journal
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    • v.44 no.6
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    • pp.966-976
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    • 2022
  • Optical wireless communication, or free space optics, is a promising solution for backhauls in sixth-generation mobile systems. However, the susceptibility of optical links to weather conditions has led to FSO links being furnished with radio frequency (RF) backups. These Hybrid FSO/RF systems provide enhanced link availability but lead to RF resource wastage. Cognitive radio technology, in contrast, is well known for its optimal use of RF resources and may be combined with an FSO link to create a Cognitive Hybrid FSO/RF system. This work uses such a system to analyze a configuration for a mobile backhaul in sixth-generation mobile systems. This configuration can seamlessly coexist with established large scale RF cellular networks. The performance of this configuration is analyzed with respect to outage probability and average bit error by considering the impact of optical channel turbulence, misalignment loss, RF interference, and noise. Mathematical closed-form expressions are verified by simulations.

Design and Implementation of Multi-mode Mobile Device for supporting License Shared Access (면허기반 주파수 공동 사용을 위한 멀티모드 단말기 설계 및 구현)

  • Jin, Yong;Choi, Seungwon
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.12 no.4
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    • pp.81-87
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    • 2016
  • Recently, as the heterogeneous network (HetNet) has been deployed widely to support various kinds of Radio Access Networks(RANs) with a combination of Macro, Pico, and/or Femto cells, research and standardization efforts have been very active regarding the concept of Licensed Shared Access (LSA) for supporting spectrum sharing. In order for a mobile device to efficiently support the spectrum sharing, the mobile device shall be reconfigurable, meaning that its radio application code has to be adaptively changed in accordance with the hopping of desired spectral band. Especially, Working Group 2 (WG2) of Technical Committee (TC) Reconfigurable Radio System (RRS) of European Telecommunications Standards Institute (ETSI) has been a main driving force for developing standard architecture for Multi-mode Mobile Device (MD) that can be applied to the LSA system. In this paper, we introduce the Multi-mode MD architecture for supporting LSA-based spectrum sharing. An implementation of a test-bed of Multi-mode MD is presented in order to verify the feasibility of the standard MD architecture for the purpose of LSA-based spectrum sharing through various experimental tests.

Required Specification Analysis of CPRI Link of 4G Mobile Networks for Using WDM-PON Transmission (WDM-PON 전송을 이용한 4G 이동통신망 CPRI 링크의 시스템 요구규격 분석)

  • Kim, Sung-Man;Mun, Sil-Gu;Lee, Sang-Soo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.7B
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    • pp.499-504
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    • 2012
  • Recently, base stations composed of digital unit (DU) and radio unit (RU) have been widely used in 4G mobile networks. To connect DU and RU, CPRI (common public radio interface) is usually used as the interface standard. This CPRI link is considered as one of the application markets for WDM-PON. In this paper, we analyzed the required specification of WDM-PON for the CPRI link of the 4G LTE-Advanced base station composed of DU and RU. This analysis is important to set a target goal of the development of WDM-PON system for 4G mobile networks.

Radiation Pattern and Radio Sensitivity of PCS Band Mobile Phones with Internal Antenna and External Antenna (PCS 대역 안테나 내장형 단말기와 외장형 단말기의 방사패턴과 무선감도)

  • 공성신;오종대;양운근
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.15 no.4
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    • pp.397-405
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    • 2004
  • In this paper, performance analysis of mobile phone with internal antenna for PCS band was carried out. The radiation patterns for antenna and mobile phone with internal antenna were simulated by using 3D simulation program, HFSS and SEMCAD. Radiation pattern variation was observed according to installation of LED circuit and ground pattern and by using simulation radiation pattern was improved. And radiation patterns of mobile phones with internal and external antennas were measured by using for field measurement system and chamber. Measured radiation pattern for mobile phone with internal antenna shows good agreement with simulation result. And the radio sensitivities of mobile phones with internal and external antennas were measured by using Agilent E5515C and chamber and compared. The measured radio sensitivity of mobile phone with internal antenna shows proper performances comparable to other model with external antenna. Measured result shows that the difference on averaged co-polar radio sensitivity is 0.12 ㏈.

Implementation of Radio Access Network for Mobile Backhaul Network (이동 백홀 네트워크용 Radio Access Network 구현)

  • Park, Chun-Kwan;Song, Han-Young;Jeon, Byung-Chun
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.10 no.6
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    • pp.77-84
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    • 2010
  • This paper aims to implement RAN(Radio Access Network) transmission system that can reduce the transmission cost by installing between mobile base station and base station controller. This system can reduce the number of transmission links by sharing the transmission link that the mobile communication stations of various generation use separately. This also can classify the traffics non-sensitive to delay time, and then transfer them through Ethernet/IP network.

A study on the allocation of Radio Resource in Mobile Communication. (이동 통신에서의 무선 자원 할당에 관한 연구)

  • 조석팔
    • The Journal of Information Technology
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    • v.4 no.3
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    • pp.65-75
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    • 2001
  • Code-division multiple access has been widely accepted as the major multiple access scheme in mobile communication systems. Wide-band CDMA and its hybrid associate time-division CDMA are key elements in the mobile communication. Since 10 years ago, there has been enormous research activity in analysis of the capacity of these CDMA-based systems. Recently, upgrading service, high quality and the different service classes in radio resource allocation has recently increased. This paper presents an overview of Radio Resource Allocation on the CDMA-based systems that are flexible, support traffic services, minimize call blocking rate and have acceptable radio resource utilization.

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Wireless Internet-IMT-2000/Wireless LAN Interworking

  • Roman pichna;Tero Ojanpera;Harro Posti;Jouni Karppinen
    • Journal of Communications and Networks
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    • v.2 no.1
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    • pp.46-57
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    • 2000
  • Ongoing standardization effort on 3G cellular system in 3GPP (UNTS) is based on GPRS core network and promises a global standard for systems capable of offering ubiquitous access to internet for mobile users. Considered radio access systems(FDD CDMA, TDD CDMA, and EDGE) are optimized for robust mobile use. However, there are alternative relatively high-rate radio interfaces being standardized for WLAN (IEEE802.11 and HIPER-LAN/2) which are capable of delivering significantly higher data rates to static or semi-static terminals with much less overhead. Also WPANs(BLUETOOTH, IEEE802.15), which will be present in virtually every mobile handset in the near future, are offering low cast and considerable access data rate and thus are very attractive for interworking scenarios. The prospect of using these interfaces as alternative RANs inthe modular UMTS architecture is very promising. Additionally, the recent inclusion of M-IP in the UMTS R99 standard opens the way for IP-level interfacing to the core network. This article offers an overview into WLAN-Cellular interworking. A brief overview of GPRS, UMTS cellular architectures and relevant WLAN standards is given. Possible interworking architectures are presented.

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An Energy-efficient MAC Protocol in Cognitive Radio Environment (Cognitive Radio 환경을 고려한 에너지 효율적인 MAC 프로토콜)

  • Kim, Byung-Boo;Rhee, Seung-Hyong
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.7 no.2
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    • pp.81-91
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    • 2008
  • In mobile wireless communications, there is a new approach that uses the lacking spectrum efficiently. A cognitive radio is a device that can changes its transmitter parameters based on interaction with the environment in which it operates. At present, the wireless communication standard for wireless device contains power-saving modes or energy efficient mechanisms which cuts off the power of transmitter and receiver for power-saving. However, in cognitive radio environment, every device has the Quiet Period for searching channel and existing energy-saving method is not appropriate to be adjust to cognitive radio environment. In this paper, we propose an energy-efficient MAC protocol of mobile device in cognitive radio environment and prove the improvement of proposed method.

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Enhanced Energy-efficient Spectrum Sensing Scheme in Cognitive Radio Networks (모바일 기기의 에너지 소모를 줄이기 위한 인지 무선 통신에서 효율적인 스펙트럼 센싱 방법)

  • Shin, Younghwan;Seo, Sunho;Chung, Jong-Moon
    • Journal of Internet Computing and Services
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    • v.20 no.2
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    • pp.1-7
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    • 2019
  • The latest mobile applications such as augmented reality, virtual reality, and deep learning can be used efficiently in various fields such as emergency management and game. Accordingly the corresponding applications have been developed for these purposes. However modern mobile applications such as augmented reality and virtual reality increase the energy burden on mobile devices. In order for mobile devices to focus their energy on the latest mobile applications, energy consumption should be minimized for communication and networking, such as cognitive radio. In this paper, we propose a method to reduce the energy consumption of Centralized Cooperative Spectrum Sensing (CCSS) scheme in cognitive radio by devising Stop Reporting Algorithm (SRA). Simulation results show that SRA can reduce energy consumption of mobile devices using cognitive radio.

Uncoordinated Dynamic Frequency Allocation Schemes based on Cognitive Radio in Mobile Cellular Networks (이동셀룰러망에서 무선 인지 기반 비협력 동적 주파수 자원 할당 기법)

  • Yu, Hyun;Jung, Jun-Woo;Lee, Jong-Kwan;Lim, Jae-Sung
    • Journal of the Korea Institute of Military Science and Technology
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    • v.14 no.5
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    • pp.833-841
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    • 2011
  • In this paper, we propose uncoordinated dynamic frequency(channel) allocation schemes based on cognitive radio in mobile cellular networks(MCNs). Under the assumptions that mobile base stations are equipped with cognitive radio(CR) function and they construct uncoordinated network, the proposed scheme enables the MCNs by suppression of successive channel switching and management of channel allocation in a dynamic and distributed manner. The proposed scheme is composed of two phase processes. In the first phase, highly orthogonal sequences are generated and assigned to mobile base stations. In the second phase, each mobile base station is allocated a channel according to the pre-assigned orthogonal sequences. Simulation results show that the number of successive spectrum switching is reduced significantly compared with the random switching scheme.