Indoor Short Range Wireless Broadband Communications Based on Optical Fiber Distribution

In order to serve the explosive demands of triple play services or multimedia services with high quality of data transmission in Fifth Generation (5G) communication systems which has availability of large spectrum unlike Fourth Generation (4G), low latency, improved transmission, and increased reliability, an access networks with optical fiber distribution network and wireless enabled technology is urgently needed and therefore, a prominent technology known as Radio over Fiber (RoF) is suggested by researcher/Scientists due to a perfect blend of flexible fiber technology and wireless mobility. RoF technology is helping the data transmission systems from last thirty years with great success and has numerous advantages such as scalability, transparency, antenna site complexity reduction, low installation cost, accessibility of radio carrier by diverse antenna sites dynamically. Millimeter waves (Mm waves) integration in 5G wireless RoF systems comes out to be an encouraging candidate to cater the bandwidth hungry current as well as future generation internet application such as high definition TV (HDTV), online games, video conferencing, and voice over IP (VoIP) etc. For the prolonged reach, economical installations, and improved performance, optimal Mm wave generation methods should be incorporated in 5G such as employing multi carrier generation technique (MCG). Deployment of single mode fiber (SMF) in 5G offers high speed, large capacity, improved security, etc., but also has a prominent limitation of nonlinear effects and it is unwanted phenomenon which degrade the system performance by introducing intermodulation distortion, distortion of signal phase, harmonic distortion, and interference in the neighbouring channels. Minimum modifications of architecture and minimum cost should be spent on the compensation of nonlinear effects or Kerr’s effects in RoF systems and recently mode division multiplexing has emerged as an ultimate solution. In this review article, detailed discussion of an evolutionary technology, i.e., RoF is presented with a literature review, present evaluations, and future challenges. Our utmost goal is to enrich the young researchers with precious aspects for RoF technology on single platform and also encourage them to conduct the technology advancement research works in various fields such as nonlinear compensation, Mm wave generation, dispersion compensation, cost reduction, complexity reduction, and security enhancements for 5G RoF systems.

현재 이동통신망에서 요구되는 많은 통신량을 수용하기 위해서 새로운 주파수 대역을 사용하는 5G New RAT(: Radio Access Technology) 에 대한 연구가 활발히 진행되고 있다. 하지만, 이러한 새로운 New RAT 기술이 이동통신에 적용되었을 때에 이를 유선 이동통신망에서 수용할 수 있을지에 대해서는 제대로 연구된 바가 없다. 따라서, 본 연구에서는 이러한 New RAT 기술을 RoF(: Radio over Fiber) 기술로 이동통신망의 Fronthaul에서 수용이 가능한지에 대한 연구를 진행하였다. 본 연구에서는 New RAT 의 기술로 밀리미터파 통신기술, 테라헤르츠파 통신기술, 무선 광통신 기술 등을 고려하고, 이들 각각에 대한 RoF 기술의 응용 가능성을 연구하였다. 연구의 결론을 요약하면, 10 년 이내의 범위에서 세 가지 New RAT 기술 중에 밀리미터파 통신기술에 대해서만 RoF 수용성을 고려하면 되는 것으로 판단되며, 빔포밍을 사용하는 경우에는 밀리미터파 통신기술의 요구 전송 대역폭이 너무 많아 Fronthaul 에서 RoF 기술로도 수용이 쉽지 않은 것으로 결론이 내려졌다. 5G New Radio Access Technology(: RAT) is studied by many researchers because the current radio frequency is insufficient to accommodate the increased mobile communication data traffic. However, there are few researches to study on the issue whether the wired mobile network can accommodate the new RAT. Therefore, in the paper, the study on the issue whether the Radio over Fiber(: RoF) system can accommodate the new RATs such as millimeter wave communication, terahertz communication, and optical wireless communication. As a result of the study, only millimeter wave communication deserve to be considered in ten years and even RoF system may not support the increased bandwidth of the millimeter wave communication when beamforming is used.

Demand for broadband access networks has grown rapidly with the increased demand for Internet connectivity and multimedia services. Fixed broadband wireless access systems based on the IEEE 802.16 standard may become a viable alternative to wired systems. In particular, the mesh networking capability added into the standard will potentially provide significantly wider broadband wireless coverage without requiring line-of-sight. In this paper, we present a transmission scheduling algorithm for the IEEE 802.16 mesh mode standard. To the best of the authors' knowledge, this is the first scheduling algorithm for a multihop network based on the 802.16 standard. Simulation results show that the proposed algorithm achieves high channel efficiency while providing equal transmission opportunity (i.e., fair access) to all nodes in the network. This study will aid network designers in fine-tuning the details of the communication system for satisfactory performance in the field

As wireless devices and the useful services they can deliver become more pervasive and affordable; the need for wireless broadband technologies meeting the demands of emerging market countries is growing. In this paper the technology choice in wireless broadband access and service architecture is discussed with reference to three important wireless broadband technologies and relevant parameters such as service activation, authentication and delivery, cost effectiveness and sustainability. The main focus of the article is towards wireless broadband technology deployment in developing countries and rural communities for providing innovative wireless broadband services.

In the present paper, radio-over-fiber (RoF) technology has been proposed, which is the integration of the optical and radio networks. With a high transmission capacity, comparatively low cost and low attenuation, optical fiber provides an ideal solution for accomplishing the interconnections. In addition, a radio system enables the significant mobility, flexibility and easy access. Therefore, the system integration can meet the increasing demands of subscribers for voice, data and multimedia services that require the access network to support high data rates at any time and any place inexpensively. RoF has the potentiality to the backbone of the wireless access network and it has gained significant momentum in the last decade as a potential last-mile access scheme. This paper gives the comprehensive review of RoF technology used in the communication system. Concept, applications, advantages and limitations of RoF technology are also discussed in this paper.

Microwave wireless and optical fiber technologies are widely used for several applications in communication, sensing, imaging, and so on. We propose an electro-optic (EO) modulator with a planar stripline feed to a gap-embedded patch-antenna for hybrid uplinks to an optical fiber and microwave wireless networks. The proposed device is designed on an EO crystal with simple and compact structure. The gap-embedded patch-antenna on the EO modulator can be operated for optical modulation to the optical fiber network. The proposed device can be also operated for microwave transmission to the air or wireless networks. Characteristic and analysis of the designed device for optical modulation and wireless microwave transmission are reported and discussed.

Future broadband access networks in the 5G framework will need to be bilateral, exploiting both optical and wireless technologies. This paper deals with new approaches and synergies on radio-over-fiber (RoF) technologies and how those can be leveraged to seamlessly converge wireless technology for agility and mobility with passive optical networks (PON)-based backhauling. The proposed convergence paradigm is based upon a holistic network architecture mixing mm-wave wireless access with photonic integration, dynamic capacity allocation and network coding schemes to enable high bandwidth and low-latency fixed and 60GHz wireless personal area communications for gigabit rate per user, proposing and deploying on top a Medium-Transparent MAC (MT-MAC) protocol as a low-latency bandwidth allocation mechanism. We have evaluated alternative network topologies between the central office (CO) and the access point module (APM) for data rates up to 2.5 Gb/s and SC frequencies up to 60 GHz. Optical network coding is demonstrated for SCM-based signaling to enhance bandwidth utilization and facilitate optical-wireless convergence in 5G applications, reporting medium-transparent network coding directly at the physical layer between end-users communicating over a RoF infrastructure. Towards equipping the physical layer with the appropriate agility to support MT-MAC protocols, a monolithic InP-based Remote Antenna Unit optoelectronic PIC interface is shown that ensures control over the optical resource allocation assisting at the same time broadband wireless service. Finally, the MT-MAC protocol is analysed and simulation and analytical theoretical results are presented that are found to be in good agreement confirming latency values lower than 1msec for small- to mid-load conditions.

Chapter 4 - Multimedia Services over Wireless Metropolitan Area Networks

Lots of emerging wireless technologies has evolved with their own advantages and disadvantages. Through the convergence of technologies, one can eliminate the drawbacks of the other. In this work, the authors first established limitations of the popular WiFi (IEEE 802.11 wireless router) radio in terms of high end multimedia data services and then redesign the IEEE 802.11 N(draft) wireless router based cells taking WiMax technology as the back bone network which results in a WMCN System. Instead of using standard DSP/BIOS based RTOS kernel, they are working on XPC target based RTOS kernel provided by Matlab using a standalone PC. This approach has enhanced the performance of the total system. The modeling and simulation of the different sub systems of WMCN are realized using Matlab & Simulink. These simulations are being ported through XPC target mode to a standalone PC for the completion of the project. Additionally, the theoretical design of Pico cell structure for the campus has been finalized. Accordingly, they are trying to invest and develop 40 such WMCN systems and run these systems for wireless multimedia broadband service.

Selective delivery of gigabit-per-second wireless and wired services is demonstrated in an integrated fiber-wireless access network using the millimeter-wave (mm-wave) radio-over-fiber (RoF) system employing the dual-sideband optical carrier suppression technique. A dual-electrode Mach-Zehnder modulator is used in this technique to generate 40 GHz carrier to distribute 1.25 Gbps data via direct modulation (DM) over a 20 km RoF system. The results show that selective signal delivery can be achieved using a low-cost DM laser diode drive current of 20 mA. The advantage of the proposed system is that it provides versatility to control the gigabit-per-second (Gbps) signal delivery in an integrated ROF-PON system with a common high frequency oscillator shared for the whole system. © 2016 Wiley Periodicals, Inc. Microwave Opt Technol Lett 58:1768–1773, 2016

The radio over fiber (RoF)-distributed antenna system (DAS) over a wavelength division multiplexing-passive optical network (WDM-PON) with multiple input multiple output (MIMO) employing bandpass-sampling and optical time division multiplexing (TDM) techniques has been proposed to realize next generation broadband wireless access with higher throughput and its preliminary feasibility has been confirmed. To investigate the performance of bandpass-sampled and time domain multiplexed optical signals, and enhance the transmission performance in the wireless link of the RoF-DAS over WDM-PON, we perform two-tone signal transmission experiments with 2.4 GHz band radio frequency (RF) signals and analyze the RF carrier power, third-order intermodulation distortion (IMD) power and noise power. The analysis results confirmed that the nonlinearity of the proposed system is mainly caused by a lithium niobate-Mach-Zehnder modulator (LN-MZM) as with the other RoF systems and that the dominant noise components are the signal-spontaneous beat noise arising from the amplified spontaneous emission (ASE) of two erbium doped fiber amplifiers (EDFAs) and the signal-signal beat noise caused by the interference between the optical TDM pulses. The latter is the specific noise component in the proposed system. In addition, we clarify the principle of the signal-signal beat noise generation and report that the signal-spontaneous beat noise can be reduced by the gain optimization of the two EDFAs.

Summary form only given. Emerging demands for high data rate multimedia based services and high spectral efficiency are the key drives for the continued technology evolution in wireless communications. Recently, several advancements have been introduced for 3G wireless communication systems to further enhance the data rate and the system performance. However, due to the proliferation of wireless multimedia applications and services such as video teleconferencing, network gaming, and high-quality audio/video streaming, it is apparent that 3G wireless systems will be unable to comply with this ever increasing demand for broadband wireless services. The next generation wireless communication systems (namely, fourth generation (4G) or beyond 3G (B3G) systems) are expected to support much higher data rate services compared to evolving 3G systems (up to 100 Mbit/s in outdoor environments and up to 1 Gbit/s in indoor environments). The major technical challenges will be achieving high spectral efficiency and handling high frequency-selectivity due to the use of large bandwidth. Hence, it has become crucial to incorporate the recent technical advances in the physical layer into the future wireless systems. In this keynote speech, an overview of leading technological advances and future trends in the physical layer that enable truly ubiquitous broadband wireless capabilities will be presented. The topics include multiple-input multiple-output (MIMO) technologies, adaptive modulation, cooperative diversity, multicarrier CDMA, ultra wideband (UWB) transmission, and cognitive radio.

Microwave photonic filters (MPFs) based on stimulated Brillouin scattering (SBS) and their applications in various microwave systems are extensively reviewed. This work summarizes the state of the art, emphasizing new methods, experimental proofs, and optimized passband properties of SBS-based MPFs. Important topics include frequency-tuning-range-extended MPFs, switchable MPFs, high-selectivity rectangular filters, and bandwidth-reconfigurable MPFs, addressing significant issues in traditional filters. Photonic technology in microwave photonics (MWP) enables processing of broadband, high-frequency microwave signals with excellent selectivity, stability, and adjustable passband properties. Applications span optical wireless communication, optical signal processing, radio over fiber (RoF) systems, satellite communications, optical sensors, and instrumentation. This review offers valuable insights into the advancements and potential impact of SBS-based MPFs in microwave systems

Demonstration high-order QAM transmission based on one-bit delta-sigma modulation in radio-over-fiber system

A novel method to generate ultra-wideband (UWB) signals based on two differential group delay modules and one Mach-Zehnder Modulator is proposed. Both simulation and experiments verified that the method could generate two kinds of UWB monocycles using low bit-rate non-return-to-zero data source (1Gbps). The monocycles have a fractional bandwidth of 127% at centre frequency 5.5GHz. Keywords: Ultra wideband (UWB), radio-over-fiber (RoF), differential group delay (DGD) 1. INTRODUCTION Ultra-wideband (UWB) is a fast emerging technology for short-range broadband wireless communication such as wireless personal area network and sensor network, etc. The UWB signal occupies wide bandwidth and has low power density, and it has immunity to multi-path fading [1]. As a carrier-free modulation scheme, direct-sequence impulse radio is more cost-effective and simpler compared with multi-band orthogonal frequency scheme. Since UWB is a room-scaled short range wireless communication technique, the wireless networks can operate mainly in indoor environment in standa lone mode. Considering the integration of UWB access networks and fixed wired networks, the combination of UWB-over-fiber technology and fiber-to-the-home (FTTH) technology is a competitive candidate for future wideband access networks [2]. So many all-optical schemes that fit for UWB-over-fiber technology to generate and distribute UWB impulses have been reported recently. Zeng et al. proposed two approaches to generate UWB impulses using one phase modulator (PM), and 25-km single mode fiber (SMF) or FBG to convert phase-modulated light to UWB pulses [3, 4]. Wang and Dong proposed UWB signal generation using cross-gain modulation or cross-phase modulation in semiconductor optical amplifier [5, 6], which requires two laser sources and may increase the system complexity. Chen proposed a scheme based on optical polarization time delay [7]. It is a simple method, but the elect rical signal source needs at least twice bit-rate compared to the carried data. Most of the schemes n eed an electrical Gaussian pulse source, which is comm only composed of a high-speed pulse pattern generator (PPG). This is an expensive construction, for which the PPG should work at least 10 Gbps. Furthermore, if data are carried on the UWB pulses, another modulator should be added to the systems, which increase the system cost and complexity. In this paper, we proposed and experimentally demonstrated a simple method to generate data-carried UWB monocycle pulses based on two differential group delay (DGD) modules and one Mach-Zehnder modulator (MZM). Instead of the data pattern “1000 0000 ”, which has one “1” followed by several “0”s to form the UWB signal, we use electrical non-return-to-zero (NRZ) data. The NRZ data modulate the optical signal in MZM to get an optical binary phase shift keying (BPSK) signal, which is then fed into two cascade DGD module s while the polarization of the light is carefully adjusted