STRIKE: spectrally efficient fixed wireless network based on dual standards

5G network is an enhanced communication network, designed to converge the requirements of quality of service (QoS) parameters, data and capacity, by means of signals with high QoS and high-speed data rate. Several state-of-art technologies are involved to obtain the requirement of energy efficient communication system with increased number of users, devices, higher data rate with low latency. This paper presents a system which demonstrates the energy and spectral efficiency achieved for various number of nodes in a specific area. This study addresses the improvement in energy and spectral efficiency when the proposed algorithm is used. The proposed algorithm is a combination of swarm based artificial bee colony (ABC) algorithm with neural network. Experimental results have been carried out to observe the performance of QoS parameters such as bit error rate (BER), throughput, power consumption and mean square error (MSE). The maximum energy efficiency achieved is 34% and Spectral efficiency is 36%.

We investigate the use of a multi-element antenna array (MEA) at the base station (BS) in a time division multiple access (TDMA) broadband fixed wireless access (BFWA) system. At high data rates the intersymbol interference (ISI) induced by dispersive channels becomes a technological bottleneck. Space-time processing at the BS offers a solution to improve the wireless link quality in the uplink. First, we investigate the performance of a space-time decision feedback equalizer (DFE) trained with the LMS algorithm for a single user BFWA system (i.e. one user per frequency channel and per time slot). Then we propose an algorithm for space division multiple access (SDMA) in the uplink based on a combination of adaptive space-time equalization and successive interference cancellation (SIC). It is shown via simulations that this combined approach offers an improvement in the probability of symbol error (P/sub s/) for a two-user system (i.e. two users per frequency channel and per time slot) compared to a space-time DFE without SIC. The RLS algorithm is used for the two-user system to ensure fast convergence. The proposed iterative approach offers a low complexity solution compared to minimum mean square error solutions based on direct matrix inversion, which would be costly for the expected delay spreads associated with BFWA systems.

Research into cutting-edge systems that can satisfy the rising needs for greater data rate and increased reliability is becoming more and more necessary as wireless communication technologies continue to evolve. To enhance the spectral and energy efficiencies, this study examine the performance of massive multiple input multiple output (mMIMO) communication systems using wavelet-order orthogonal frequency division multiplexing (W-OFDM). Also, a communication system was created based on W-OFDM Massive MIMO using MATLAB to model its operation. The simulated system's various stages of operation was examined through detailed analysis and its performance was compare with prior studies and practical networks on OFDM. Key performance metrics, specifically the data throughput, was evaluated to assess the effectiveness and viability of the system. The simulation results indicates that W-OFDM can achieve up to 35% reduction in peak-to-average-power-ratio (PAPR) compared to the traditional OFDM, with a 20% improvement in BER performance under Rayleigh fading conditions. Also, the spectral efficiency of W-OFDM mMIMO outperforms convectional OFDM by 15%, making it a viable technology for future communication networks requiring high data rates and reliability. This implies that, the analytical evaluation confirms that W-OFDM mMIMO provides substantial benefits for improving energy and spectral efficiencies in wireless communication systems, addressing the challenges of increased user demands for high spectrum. This study contributes to the understanding of MIMO systems' performance optimization, highlighting the importance of antenna configuration and cell distance. Comprehensive analysis of spectral efficiency and energy efficiency trade-offs in MIMO systems and identification of optimal antenna configuration for maximum energy efficiency, addressing some of the challenges of future wireless communication systems.

The importance of the development of laser telemetry for reception of scientific data from space is pointed out by J. Bland-Hawthorn et al. in their Policy Forum “Laser telemetry from space” (26 July, p. 523). The authors consider the limitations to data communication in the microwave range due to spectrum allocations, but they do not consider the fundamental limitations for both radio and optical communications due to the signal-to-noise average power ratio as expressed by Shannon ([1][1], [2][2]). The spectrum allocation limit is relevant for near-Earth applications, but for the important case of communication at distances of 0.1 astronomical units (AU) and beyond, the signal-to-noise limit is dominant. At large distances, the radio and optical communication rates feasible in the next 15 years are comparable. This situation is illustrated in the figure, which plots data rate as a function of distance for three cases: (i) NASA's current radio Deep Space Network (DSN), (ii) optical technology expected to be available by 2010, and (iii) a future large radio array, such as discussed recently in Science (“Tuning in the radio sky,” R. Irion, 3 May 2002, p. [830][3]). ![Figure][4] Comparison of current and future radio and optical communication rates at astronomical distances. Data rate ( 3 ) versus distance for DSN (blue), expected optical technology (purple), and a future large radio array (red). The leveling off of the radio data rate at distances less than 0.2 AU (about 30 million km) is due to spectrum allocations of 50 MHz for the current DSN at 8.4 GHz and 500 MHz at 32 GHz for a future large array. The data rate in bits/second can exceed the bandwidth in hertz by using multilevel coding but has a flat logarithmic dependence on signal-to-noise ratio and, hence, distance. At the distance of Jupiter, the current radio data rate is limited by signal-to-noise ratio on the order of 50 kbits/s, which is three orders of magnitude lower than the spectrum allocation. An important goal is video data rates from the outer planets, which requires on the order of 5000 kbits/s. This rate is feasible with SKA-class large radio arrays that are under development for radio astronomy and are under consideration by NASA for space communications. Other factors such as the proven reliability of current spacecraft radio transmitters, sensitivity to location of the sun, spacecraft vibration and pointing requirements, and availability due to weather conditions (clouds) all need to be considered. Radio spectrum allocations of several GHz in the 100-GHz frequency range have yet to be explored. Both optical and radio communications need to be developed for future space communications of scientific data. 1. 1.[↵][5]1. C. Shannon , Bell System Tech. J. 27, 379 (1948)623. [OpenUrl][6][CrossRef][7][Web of Science][8] 2. 2.[↵][9]The Shannon limit is given by C = B .log2 (1 + S / N ), where C is the data rate in bits/s, B is the channel bandwidth in Hz, and S and N are the average signal and noise powers. It is important to note that N is proportional to B and refers to additive noise due to background sources and detectors and not the fluctuations due to the Poisson distribution of signal photons. 3. 3.The data rates in the figure are all for 50 W of DC power consumption and similar communication equipment mass of 18 kg at the spacecraft and assume 9 dB of link margin to account for atmospheric variations, error-correction coding efficiency, and component degradations. The 2010 optical link assumes a 10-m receiving antenna on Earth, a 0.3-m-diameter transmit antenna, a background noise level (daytime) of 10 quanta, and a data rate increase of of 1/ln 2 = 1.442 allowed by the Shannon limit for an optimum bandwidth much greater than data rate. The current radio link assumes a 70-m DSN antenna, 1.5-m-diameter transmit antenna, and total system noise of 54 quanta ( T sys = 22 K at 8.4 GHz). The future large array assumes 3600-by 12-m-diameter antennas, 1.5-m transmit antenna, and total system noise of 26 quanta ( T sys = 40K at 32 GHz). # Response {#article-title-2} Radio communication technology has been around for a very long time and is now so nearly optimized that little improvement can be anticipated unless increasingly large and correspondingly costly antenna arrays are constructed. Optical/near-infrared communications are still in their infancy. But, in many applications, the high inherent bandwidth of optical frequencies should ultimately make them far more powerful than radio waves. Our Policy Forum anticipated that near-infrared telemetry techniques would take the lead in communication across space sometime in the next decade. Weinreb correctly points out the importance of Shannon's limit on data transmission rates in telemetry across vast stretches of space. Our Policy Forum took this limit into full account, albeit without specific mention. For transmission from the astronomically important Lagrangian point L2 at 0.01 AU, Weinreb's plot clearly illustrates the large advantage that optical telemetry has even over the most ambitious currently projected radio techniques. Over greater interplanetary distances, Weinreb's plot shows the future radio array winning out at radio frequencies, but this is only because he compares laser transmission with a relatively small 0.3-m transmitting antenna to radio transmission with a 1.5-m-diameter antenna. With comparable transmitting dishes, the two systems would perform equally well. For regular access from space, ground receiving stations need to be distributed around the globe to assure communication at all times of day. The anticipated ground stations for near-infrared telemetry are expected to be affordable and more easily installed at widely distributed sites. The billion-dollar Square Kilometer Array will be a wonderfully powerful astronomical instrument, but it should, and most probably will, be used primarily for exquisitely sensitive radio astronomical observations rather than for spacecraft telemetry. [1]: #ref-1 [2]: #ref-2 [3]: /lookup/doi/10.1126/science.296.5569.830 [4]: pending:yes [5]: #xref-ref-1-1 View reference 1. in text [6]: {openurl}?query=rft.jtitle%253DBell%2BSystem%2BTech.%2BJ.%26rft.volume%253D27%26rft.spage%253D379%26rft_id%253Dinfo%253Adoi%252F10.1002%252Fj.1538-7305.1948.tb01338.x%26rft.genre%253Darticle%26rft_val_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Ajournal%26ctx_ver%253DZ39.88-2004%26url_ver%253DZ39.88-2004%26url_ctx_fmt%253Dinfo%253Aofi%252Ffmt%253Akev%253Amtx%253Actx [7]: /lookup/external-ref?access_num=10.1002/j.1538-7305.1948.tb01338.x&link_type=DOI [8]: /lookup/external-ref?access_num=A1948UH03900001&link_type=ISI [9]: #xref-ref-2-1 View reference 2. in text

Within the last years a discrepancy between the spectrum licenses and the actual usage of spectrum has been observed. While the vast majority of frequency bands attractive for wireless communication are licensed, measurement campaigns have shown that large portions of the spectrum are temporarily unused in many locations. Sensing-based opportunistic spectrum re-usage has been identified as an attractive approach to overcome this discrepancy. In this approach Cognitive Radio (CR) based Secondary Users (SUs) sense the licensed frequency bands owned by Primary Users (PUs) for available spectrum and use the temporarily available spectrum on an opportunistic basis with the constraint to vacate the spectrum as soon as the license holder returns. An apparent challenge for such secondary spectrum usage is the reliable detection of the PU communication. The SUs have to ensure that the licensed spectrum is always vacated in a timely manner and that no harmful interference is created to the PUs. However, not only the protection of the PU communication is a challenging task for such CR networks but also the maintenance of a proper Quality of Service (QoS) for the secondary communication. Due to the strict access priority of the PUs, the secondary communication potentially has to be often relocated to new, temporarily available frequency bands. In this thesis we present and evaluate a CR system design, which is able to cope with these two challenges. We show that the proposed system design can achieve both reliable PU protection and secondary QoS support even for small secondary networks consisting of simple, low complexity CRs using energy detection-based spectrum sensing for the PU protection. Using a proper amount of spectral overhead for spectrum sensing and for secondary QoS support, reliable PU protection and secondary QoS support can also be maintained in environments with very high variability of temporarily available spectrum. We evaluate the tradeoff between both overheads and show that there exists an optimal joint spectral overhead which maximizes the spectral efficiency. We further show that, while the spectral efficiency of initially small network deployments based on the proposed system design might be low, it is still significantly greater than zero. Furthermore, the spectral efficiency is improved, as the network size increases. This makes the proposed CR design an ideal approach for initial deployments of very small and cheap CR networks, which are perfectly scalable: with an increase of network size (which usually goes hand in hand with an increase in spectrum demand), also the spectral efficiency is increased.

Fixed Broadband Wireless Access (FBWA) technology is designed to serve as a wireless DSL replacement technology to provide broadband access in underserved areas where no other access technology exists. Due to the enormousness of the target service area, relay equipment play an important role in such networks, and the installation and maintenance cost of the network is directly proportional to the cost of the relay equipment. To minimize the network operational cost, we develop an optimization framework which computes the minimum number of relay stations and their placement in the network such that the demands from the end users are met.

The next-generation mobile communication network (5G) is a heterogeneous network, and it has the added advantage in the wireless communication field. Users will feel uninterrupted communication over the 5G network. It required a higher bandwidth in order to achieve a higher data rate. 5G is classified into three categories such as ultra-reliable low latency communication (URLLC), massive machine-type communication (mMTC), and enhance mobile broadband (eMBB) by the International Telecommunication Union (ITU). 5G will provide the higher data rate (Gbps), low latency, enhance quality of service (QoS), low energy consumption at a low cost per transmission, better spectral efficiency (SE), energy efficiency (EE), quality of service (QoS), improved throughput and better user experience. There will be so many challenges to achieve the above-mentioned factors. The main challenges are to reduce Interference, latency, power consumption, and enhance data rate. The paper highlights the different issues and challenges of 5G and compare different existing methodologies for mitigating these challenges.Keywords5GHeterogeneous networkMillimeter waveCoverage areaInterferenceLatencySpectral efficiencyEnergy efficiencyLow power consumption

Long Term Evolution (LTE) is one of the standards in 4G cellular technologies which offer different data rates for voice, video conference and other services. The Orthogonal Frequency Division Multiple Access (OFDMA) is a well suited multiple access scheme of LTE for supporting variable bit rate services. OFDMA-based Cellular communication network face serious challenges in providing good Quality of Service (QoS) to the users. In order to provide good QoS, network operators have to make the effective use of their available resources, which leads to effective network design and network planning. Erlang capacity is the dominant parameter used for effective network design and network planning. Co-channel Interference is an important limiting factor for Erlang capacity in OFDMA-based cellular systems. The capacity of a OFDMA cellular network is determined by the amount of CCI it can tolerate. In this paper a new method is proposed for the evaluation of Erlang capacity of a OFDMA system under CCI. The Erlang capacity of OFDMA-based cellular systems under CCI is evaluated and compared for different number of co-channel interferers, various spectral efficiencies, voice activity factors and various data rates.

Wireless Multimedia Sensor Networks (WMSN) are designed to transmit audio and video streams, still images and scalar data. Multimedia transmission over wireless sensor network has many killer applications like, video surveillance system, object tracking, telemedicine, theft control system and traffic monitoring. Researchers are facing many challenges such as higher data rate, lower energy consumption, reliability, signal detection and estimation, uncertainty in network topology, Quality of Service and security related issues to accomplish various applications of WMSN. Multiple Node Multiple Input Multiple Output (MN-MIMO) properties have been used to improve system performance in terms of data rate, energy consumption and channel capacity. In this paper, mathematical model is presented to calculate and analyze various parameters of the network like, SNR, channel capacity and data rate. Simulation results demonstrate the effect of various channel models on output in deep fading environment and proposed channel model performs better for WMSN compare to non-adaptive system in terms of Bit Error Rate.

The increased uplink traffic of enhanced mobile broadband (eMBB) applications necessitates high data rates, extreme spectral efficiency, low latency, and less pending data in the buffer. Besides, radio resource management and optimal use of the limited spectrum have consistently been the most critical issues to address across successive generations of mobile networks. Hence, fulfilling quality of service (QoS) requirements for eMBB uplink applications and Improving the users' quality of experience (QoE) while optimizing the use of limited resources is very challenging. This paper focuses on eMBB applications whose challenges lie in improving the bit rate reached by the user, avoiding the buffer's overflow by downsizing the pending data in the buffer, and taking efficient decisions to use the limited radio resources appropriately. Our scheduling algorithm solution, uplink based, aims to share radio resources appropriately and meet the requirements of eMBB uplink applications. The paper discusses and details the method used to optimize the radio resources while improving the flow efficiency by exploiting the buffer state parameter. The simulation results show that the solution presented in this paper is more accurate than other algorithms in the literature based on spectral efficiency and buffer state and provides a good compromise between resource sharing equity level and the end user's data rate while guaranteeing a minimum acceptable throughput to edge cell users.

In order to tackle the increasing heterogeneous global Internet traffic, mixed-line-rate (MLR) optical wavelength division multiplexed (WDM) networks have emerged as the cost- and power-efficient solution. In MLR WDM networks, channels are structured as sub-bands, each of which consists of wavelengths operating at a similar data rate. By reducing the (1) spacing within a sub-band, or (2) spacing between sub-bands operating at different data rates, spectral efficiency can be improved. However, owing to high physical layer impairment levels, decrease in sub-band spacing adversely affects transmission reach of the channels, which results in higher power consumption due to requirement of increased signal regeneration. In this work, we compare power efficiency of various MLR and single-line-rate (SLR) solutions, and also investigate the trade-off that exists between spectral and power efficiency in a WDM network. Simulation results indicate that (1) for high transmission capacities, a combination of 100 Gbps transponders and 40 Gbps regenerators will obtain the highest power efficiency; (2) for long connection distances, a point ofmerging occurs for various SLR and MLR designs, where power consumption is independent of the frequency band distribution; and (3) for MLR systems, both spectral and power efficiency can be improved by using either shorter links with higher bandwidth assignment to 100 Gbps wavelengths, or longer links with higher bandwidth assignment to 40 Gbps wavelengths. Finally, the results indicate that focusing on spectral efficiency alone results in extra power consumption, since high quality of transmission and spectral efficiency leads to increased regeneration.

ETXOP: A resource allocation protocol for QoS-sensitive services provisioning in 802.11 networks

Green deployment for cellular eNodeBs has been proposed recently to save power and reduce the huge amount of carbon dioxide (CO 2) emitted by traditional power‐hungry base stations. Green eNodeBs should also be subjected to restrictions on high data rate and quality of service (QoS), which both entail a high level of power consumption. In this regard, this paper addresses the trade‐off between energy efficiency (EE) and spectral efficiency (SE) in both traditional and green long‐term evolution eNodeBs without sacrificing the QoS. EE is proved to monotonically increase with SE in traditional macrocells and quasi‐concave in green macrocells. Accordingly, a new mapping between channel quality indicator and modulation and coding scheme is proposed to address EE–SE trade‐off with the use of a multi‐criteria decision‐making technique. Then, a self‐configured link adaptation (SCLA) algorithm is developed to ensure that the priority weights related to EE and SE are adapted according to network load with the use of real‐time cross‐layer optimization. Simulation results show that the proposed SCLA provides a significant gain in EE and 52% reduction of CO 2 while maintaining SE close to the optimal value. Current and next‐generation cellular networks require such interactive techniques in order to be self‐optimised without complex modifications. Copyright © 2014 John Wiley & Sons, Ltd.

Enhanced mobile broadband (eMBB) is a major scenario in the prospective fifth generation (5G) wireless communications. Achieving high user experienced data rate (UEDR) is one of vital goals of eMBB, which needs to consume massive bandwidth. Considering the limited radio frequency (RF) spectrum resource has got heavily congested, we explore the multi-packet reception (MPR) aided visible light communications (VLCs) system to support eMBB services in this paper. MPR can efficiently alleviate collisions for VLC system and enhance UEDR. However, the implementation of MPR in random access system is challenging because of dynamic and unpredictable transmissions of eMBB terminals. For fully utilizing MPR capability and promoting UEDR maximally, we design a two-period frame structure including the access request period (ARP) and the data transmission period (DTP). UEDR emphasizes not only the data rate measured in physical layer but also the network operation behaviour experienced by users which connects closely with quality of service (QoS). In this paper, effective capacity (EC) is employed to depict UEDRs for eMBB terminals for the first time, which provides an efficient link model to evaluate data rates with consideration of statistical delay QoS. Then, the aggregate UEDR is derived and defined as a system metric, which reflects the transmission features of both two periods. We formulate the hybrid access algorithm for eMBB terminals with heterogeneous QoS requirements as an aggregate UEDR maximization problem and find the optimum access probability (for ARP) and optimal resource allocation strategy (for DTP) via the particle swarm optimization-initialization intervention (PSO-II) algorithm.

The demand for higher data rate and better quality of service (QoS) in wireless communications was growing fast in the past few years. Obtaining these requirements becomes challenging for wireless communication systems due to the problems of channel multi-path fading, higher power and bandwidth limitations. One of the most promising solutions to this problem is Multiple Input Multiple Output (MIMO) system. This paper proposed a combined spatial multiplexing MIMO scheme with beamforming for high data rate wireless communication. The proposed transmission scheme combines the benefits of both techniques and the system was able to transmit parallel data streams as well as providing beamforming gain. Actually, these diverse techniques, share the same requirement of multiple antenna elements, but differ in the antenna element spacing necessary for the different schemes to work. Thus, smart antenna array was proposed as a possible solution and was adopted at the both transmitter and the receiver. The hybrid technique provides higher spectral efficiency and improve better Bit error rate (BER) of the system than the conventional MIMO, spatial multiplexing and beamforming techniques under the same simulation environment.