Papers by Dawit Hadush Hailu
Indonesian Journal of Electrical Engineering and Computer Science
Wireless sensor networks (WSNs) are now adopting mobile sensors due to their increased popularity... more Wireless sensor networks (WSNs) are now adopting mobile sensors due to their increased popularity in research and industry. To enhance WSNs' performance, mobility can be utilized to gather data. But, if the collector's route is fixed and movement is not manageable, current quality of service (QoS) strategies and protocols are ineffective in achieving timely data delivery while maintaining energy efficiency. In the real world, WSN networks use both actuator - actuator and sensor - actuator coordination. To conserve energy in communicati on tasks with heavy traffic and high volume, sensors/actuators can be relocated to desired locations. This study introduces a routing protocol that optimizes delivery latency and energy conservation in WSNs. The proposed latency, energy, and quality of ser vice aware (LEQA) protocol uses a cooperative approach to track the sink and coordinate communication between sensors and actuators. Each sensor schedules its time division multiple access (...
arXiv (Cornell University), Dec 16, 2019
With the advent of several new Cloud Radio Access Network (C-RAN) technologies, today's networkin... more With the advent of several new Cloud Radio Access Network (C-RAN) technologies, today's networking environment is dramatically altered and is experiencing a rapid transformation. One of the most important is Ethernet based C-RAN, in support of which many products such as optical Ethernet switches have recently appeared on the market. This paper presents the performance analysis of such switches with respect to Packet Loss Ratio (PLR), Latency and Packet Delay Variation (PDV). We employed the Simula based on Discrete Event Modelling on Simula (DEMOS), a context class for discrete event simulation to simulate a cut-through optical Ethernet switch under two types of traffics: High priority (HP) traffic and Low priority (LP) traffic. In this way, the paper evaluates the optical Ethernet switch performance quantitatively. The results obtained from the simulator showed that the high quality of service was reflected on HP traffic and the low quality of service in LP traffic. Hence, HP traffic can be used for transporting Radio over Ethernet (RoE) traffic while LP traffic can used for transporting time insensitive application. It is also found that HP traffic experiences a PDV equals to the duration of maximum sized LP traffic in Optical Ethernet switch.
ArXiv, 2019
Today, deployment of optical fiber has offered large transmission capacity which cannot be effici... more Today, deployment of optical fiber has offered large transmission capacity which cannot be efficiently utilized by the electronic switches. Rather, Integrated Hybrid Optical Network (IHON) is a promising approach which combines both packet and circuit switching techniques. As a result, it achieves efficient utilization of the bulk capacity and guarantees absolute Quality of Service (QoS) by optimizing the advantages of the two switching schemes while diminishing their disadvantages. Transpacket has developed a Fusion node implementing IHON principles in Ethernet for the data plane. Hence, this paper investigates and evaluates IHON network for 5G access networks. The simulated results and numerical analysis confirm that the Packet Delay Variation (PDV), Delay and Packet Loss Ratio (PLR) of Guaranteed Service Transport. (GST) traffic in IHON network met the requirements of 5G mobile fronthaul using CPRI. The number of nodes in the network limits the maximum separation distance between...
Increasing mobile data traffic due to the rise of both smartphones and tablets has led to high-ca... more Increasing mobile data traffic due to the rise of both smartphones and tablets has led to high-capacity demand of mobile data network. To meet the ever-growing capacity demand and reduce the cost of mobile network components, Cloud Radio Access Network (C-RAN) has emerged as a promising solution. In this network, the mobile operator s Remote Radio Head (RRH) and Base Band Unit (BBU) are often separated and the connection between them has very tight timing and latency requirements imposed by Common Public Radio Interface (CPRI) and 3rd Generation Partnership Project (3GPP). This fronthaul connection is not yet provided by packet based network. To employ packet-based network for C-RAN fronthaul, the carried fronthaul traffic are needed to achieve the requirements of fronthaul streams. For this reason, the aim of this study was focused on investigating and evaluating the feasibility of Integrated Hybrid Optical Networks (IHON) and Ethernet networks for mobile fronthaul. The fronthaul requirements used to evaluate and investigate these networks were maximum End to End (E2E) latency, Packet Loss Ratio (PLR) and Packet Delay Variation (PDV). TransPacket AS (www.transpacket.com) develops a fusion switching that efficiently serves both Guaranteed Service Transport (GST) traffic with absolute priority and packet switched Statistical Multiplexing (SM) best effort traffic. Dedicated wavelength is used to provide a deterministic circuit switched transport and uses the leftover capacity on the wavelength to transport the best effort traffic without affecting the absolute priority packets. We verified how the leftover capacity of fusion node can be used to carry the low priority packets and how the GST traffic can have deterministic characteristics on a single wavelength by delaying it with Fixed Delay Line (FDL). For example, for SM load=0.3 the added SM traffic increases the 10GE wavelength utilization up to 89% without any losses and with SM PLR=1E-03 up to 92% utilization. The simulated results and numerical analysis confirm that the PDV and PLR of GST traffic in IHON network and the PLR of High Priority (HP) traffic in Ethernet network meet the requirements of mobile fronthaul using CPRI. However, the PDV of HP traffic meets the fronthaul network when the number of nodes in the Ethernet network is at most four. For both IHON and Ethernet network, the number of nodes in the network limits the maximum separation distance between BBU and RRH (link length); for increasing the number of nodes, the link length decreases. Consequently, Radio over Ethernet (RoE) traffic should receive the priority and Quality of Service (QoS) only GST or HP can provide. On the other hand, SM or Low Priority (LP) classes are not sensitive to QoS metrics and should be used for transporting time insensitive applications and services. Furthermore, we numerically evaluated the performance of active Wavelength Division Multiplexing (WDM) when Optical Transmission Network (OTN) encapsulation is employed and dedicated fronthaul net- works in terms of the maximum one-way latency and the maximum separation distance between BBU and RRH provided that the typical values of BBU are known
Optical Switching and Networking, 2018
Switched (OPS) technology is under study as a promising solution for addressing the rapid growth ... more Switched (OPS) technology is under study as a promising solution for addressing the rapid growth of network-intensive applications having different Quality of Service (QoS) requirements. By employing Optical Circuit Switched (OCS) networks, an optimized Packet Loss Ratio (PLR), delay and Packet Delay Variation (PDV) performance can be obtained. It is, however, very demanding to offer a QoS comparable to OCS network through the OPS network in order to support a significant and growing number of applications. Thus, moving from OCS to OPS network, QoS is a critical issue. Hence, this paper analyzes the QoS requirements of network-intensive applications and services. Moreover, the paper derived an expression for performance metrics of a single OPS switch and ring OPS network. It is found that the International Telecommunication Union-Telecommunication (ITU-T) classification is extended with the new requirements of applications and services. For example, the upper bound delay, PDV and PLR of video streaming requires (100 ms, 400 ms), 50 ms and 1E −05 respectively. In this work, these values are improved as delay within 10 ms, PDV in micro seconds and PLR of 1E −07 at full load. It is also shown that a Fixed Delay Line (FDL) has to be considered when low PLR is required and when PDV and delay are not critical issues.
Wireless Personal Communications, 2020
Recently, to satisfy the ever-growing data needs, Long Term Evolution (LTE) has been deployed by ... more Recently, to satisfy the ever-growing data needs, Long Term Evolution (LTE) has been deployed by many operators. LTE enables better spectrum management and avoids the adjacent channel interference by using the Orthogonal Frequency Division Multiple Access (OFDMA) for downlink and Single Carrier Frequency Division Multiple Access (SC-FDMA) for uplink connection. Even though the spectrum is limited, the number of active devices is increasing which requires the need for extra spectrum. OFDM is capable of better Quality of Service (QoS) as it avoids the multipath fading using equalization and immune to inter-symbol interference, in addition to its attractive spectral efficiency. However, the LTE system is suffered from Peak to Average Power Ratio (PAPR) which reduces the QoS of the communication. Therefore, in this paper, we have proposed a QoS enhancement using a hybridized clipping-selective mapping (Clip-SLM) technique. Different QoS enhancement methods are evaluated for different modulation techniques, phase sequences, and number of sub-carriers. From the simulation results, we have shown that the proposed hybridized technique results in significant PAPR reduction which results in substantial Bit Error Rate (BER) reduction and hence QoS enhancement.
Heliyon, 2020
In optical networks, such as OPS/OBS, the network results into significant loss in the network la... more In optical networks, such as OPS/OBS, the network results into significant loss in the network layer. When the loss significantly deteriorates the QoS by increasing the Bit Error Rate (BER), a viable approach can be used to increase the performance. This paper presents state of the art of Quality of Service (QoS) schemes used for improving the performance of optical networks. Furthermore, some possible applications and performance data are summarized based on Packet Loss Rate (PLR), secrecy, survivability and other parameters. The different states of art methods proposed by several authors are compared with Coded Packet Transport (CPT) scheme. We believe that this study is valuable to researchers envisaging a novel approach to enhance the performance of optical networks for telecommunications networks of the future.
Indonesian Journal of Electrical Engineering and Computer Science, 2019
The major enemy of wireless communication is multipath fading that highly degrades the received s... more The major enemy of wireless communication is multipath fading that highly degrades the received signal. Spatial diversity highly reduces deep fades of the wireless communication. Higher signal to noise ratio (SNR) requirement can be reduced by using space time coding. In this paper, the error performance of un-coded MIMO, different diversity combing methods, space time block codes and space time trellis codes are analyzed using different parameters including number of antennas, M-array modulations, trace criteria, rank and determinant. The simulation results have shown that the Bit Error Rate (BER) significantly reduces with increasing number of receiver antennas. However, the number of antennas that a mobile device can have is limited by its size and this is inconvenient for mobile communication. Hence, this paper suggests space time codes to mitigate multipath problems in mobile communication. So, BER performance of space time block codes scheme was evaluated by varying the number...
Indonesian Journal of Electrical Engineering and Computer Science, 2019
There are many students and researcher who doesn’t really understand the practical operating prin... more There are many students and researcher who doesn’t really understand the practical operating principle of digital communication system. Hence in this paper, the digital communication system is studied and simulated. In the system kit development text and audio inputs are taken and encrypted with different encryption techniques including additive cipher, multiplicative cipher and affine ciphers. The encrypted data is converted in to an 8-bit binary, channel encoded with distinct channel coding styles like linear block encoder, cyclic encoder and convolutional encoder, line coded and band pass modulated by different digital modulation techniques. Finally, the developed software is tested with equivalent inputs of the current national TV broadcasting and the results found are correct according to the theoretical analysis of the discussion.
Indonesian Journal of Electrical Engineering and Computer Science, 2020
Today, deployment of optical fiber has offered large transmission capacity which cannot be effici... more Today, deployment of optical fiber has offered large transmission capacity which cannot be efficiently utilized by the electronic switches. Rather, Integrated Hybrid Optical Network (IHON) is a promising approach which combines both packet and circuit switching techniques. As a result, it achieves efficient utilization of the bulk capacity and guarantees absolute Quality of Service (QoS) by optimizing the advantages of the two switching schemes while diminishing their disadvantages. Transpacket has developed a Fusion node implementing IHON principles in Ethernet for the data plane. Hence, this paper investigates and evaluates IHON network for 5G access networks. The simulated results and numerical analysis confirm that the Packet Delay Variation (PDV), Delay and Packet Loss Ratio (PLR) of Guaranteed Service Transport. (GST) traffic in IHON network met the requirements of 5G mobile fronthaul using CPRI. The number of nodes in the network limits the maximum separation distance between...
Indonesian Journal of Electrical Engineering and Computer Science, 2020
With the advent of several new cloud radio access network (C-RAN) technologies, today’s networkin... more With the advent of several new cloud radio access network (C-RAN) technologies, today’s networking environment is dramatically altered and is experiencing a rapid transformation. One of the most important is ethernet based C-RAN, in support of which many products such as optical Ethernet switches have recently appeared on the market. This paper presents the performance analysis of such switches with respect to packet loss ratio (PLR), latency and packet delay variation (PDV). We employed the Simula based on discrete event modelling on Simula (DEMOS), a context class for discrete event simulation to simulate a cut-through optical ethernet switch under two types of traffics: high priority (HP) traffic and low priority (LP) traffic. In this way, the paper evaluates the optical Ethernet switch performance quantitatively. The results obtained from the simulator showed that the high quality of service was reflected on HP traffic and the low quality of service in LP traffic. Hence, HP traf...
Optical Switching and Networking, 2018
C-RAN is an architecture for future 5G cellular networks, which has the potential of combining em... more C-RAN is an architecture for future 5G cellular networks, which has the potential of combining emerging technologies from both the wireless and the Information Technology (IT) industries by incorporating cloud computing into Radio Access Networks (RANs). This paper presents a comprehensive review of the transport options for constructing mobile fronthaul, capable of supporting applications and services beyond LTE advanced. The architecture of C-RAN is first studied which comprises mobile backhaul, mobile fronthaul and the User Equipment (UE). Then, it describes the different fronthaul transport options that are capable to the drastic increase of wireless bandwidth as well as the massive deployment of small cells. It also numerically evaluated the End to End (E2E) latency, the maximum possible separation distance between Remote Radio Head (RRH) and Base Band Unit (BBU), and Packet Delay Variation (PDV) of the mobile fronthaul solutions with emphasis on Ethernet network. Moreover, the paper explains Ethernet frame format for transporting Radio over Ethernet (RoE) traffic. Finally, the paper presents a summary of emerging research directions, opportunities and challenges in optical networking in mobile fronthual networks.
Heliyon, 2019
Wireless communication requires an effective antenna synthesis that characterizes adequate infras... more Wireless communication requires an effective antenna synthesis that characterizes adequate infrastructures to provide the broader bandwidth and reduced interference. Antenna design with minimal signal degradation, optimal gain directive main beam to sustain minimal loss has been a hot issue among many communication engineers for several years. In this paper, the effects of eccentricity of the antenna, element-spacing, number of elliptical rings and number of elements are evaluated. For efficient antenna synthesis, deep Side Lobe Level (SLL) reduction and superior directivity are critical. We have also studied the significance of hyper beamforming in Elliptical Cylindrical Antenna Array (ECAA) in comparison to the geometric configuration of the antenna parameters (eccentricity of the antenna, element-spacing, number of elliptical rings and number of elements). The hyper beam exponent has resulted in flexible pattern synthesis while simultaneously reducing the side lobe of the proposed antenna array, thus decreasing the SLL and increasing directivity that are vital for wideband applications.
Indonesian Journal of Electrical Engineering and Computer Science, 2017
Increasing mobile data traffic due to the rise of both smartphones and tablets has led to high-ca... more Increasing mobile data traffic due to the rise of both smartphones and tablets has led to high-capacity demand of mobile data network. To meet the ever-growing capacity demand and reduce the cost of mobile network components, Cloud Radio Access Network (C-RAN) has emerged as a promising solution. In such network, the mobile operator’s Remote Radio Head (RRH) and Base Band Unit (BBU) are often separated and the connection between them has very tight timing and latency requirements imposed by Common Public Radio Interface (CPRI) and 3rd Generation Partnership Project (3GPP). This fronthaul connection is not yet provided by packet based network. To employ packet-based network for C-RAN fronthaul, the carried fronthaul traffic are needed to achieve the requirements of fronthaul streams. For this reason, the aim of this paper is focused on investigating and evaluating the feasibility of Ethernet networks for mobile fronthaul. The fronthaul requirements used to evaluate and investigate th...
Indonesian Journal of Electrical Engineering and Computer Science, 2017
Cloud Radio Access Network (C-RAN) has emerged as a promising solution to meet the evergrowing ca... more Cloud Radio Access Network (C-RAN) has emerged as a promising solution to meet the evergrowing capacity demand and reduce the cost of mobile network components. In such network, the mobile operator's Remote Radio Head (RRH) and Base Band Unit (BBU) are often separated and the connection between them has very tight timing and latency requirements. To employ packet-based network for C-RAN fronthaul, the carried fronthaul traffic are needed to achieve the requirements of fronthaul streams. For this reason, the aim of this paper is focused on investigating and evaluating the feasibility of Integrated Hybrid Optical Network (IHON) networks for mobile fronthaul. TransPacket AS (www.transpacket.com) develops a fusion switching that efficiently serves both Guaranteed Service Transport (GST) traffic with absolute priority and packet switched Statistical Multiplexing (SM) best effort traffic. We verified how the leftover capacity of fusion node can be used to carry the low priority packets and how the GST traffic can have deterministic characteristics on a single wavelength by delaying it with Fixed Delay Line (FDL). For example, for L1GE SM =0.3 the added SM traffic increases the 10GE wavelength utilization up to 89% without any losses and with SM PLR=1E-03 up to 92% utilization. The simulated results and numerical analysis confirm that the PDV and PLR of GST traffic in Ethernet network meet the requirements of mobile fronthaul using CPRI. For Ethernet network, the number of nodes in the network limits the maximum separation distance between BBU and RRH (link length); for increasing the number of nodes, the link length decreases. Consequently, Radio over Ethernet (RoE) traffic should receive the priority and Quality of Service (QoS) HP can provide. On the other hand, Low Priority (LP) classes are not sensitive to QoS metrics and should be used for transporting time insensitive applications and services.
Optical Fiber Technology, 2017
With the growth of Internet traffic, an inevitable use of optical networks provide a large bandwi... more With the growth of Internet traffic, an inevitable use of optical networks provide a large bandwidth, fast data transmission rates and Quality of Service (QoS) support. Currently, Optical Burst Switched (OBS)/ Optical Packet Switched (OPS) networks are under study as future solutions for addressing the increase demand of Internet traffic. However, due to their high blocking probability in the intermediate nodes they have been delayed in the industries. Packet loss in OBS/OPS networks is mainly occur due to contention. Hence, the contribution of this study is to analyze the file loss ratio (FLR), packet overhead and number of disjoint paths, and processing delay over Coded Packet Transport (CPT) scheme for OBS/OPS network using simulation. The simulations show that CPT scheme reduces the FLR in OBS/OPS network for the evaluated scenarios since the data packets are chopped off into blocks of the data packet for transmission over a network. Simulation results for secrecy and survivability are verified with the help of the analytical model to define the operational range of CPT scheme.
EURASIP Journal on Wireless Communications and Networking, 2019
Among the hot issues of the Fifth Generation (5G), developing by the Third Generation Partnership... more Among the hot issues of the Fifth Generation (5G), developing by the Third Generation Partnership Project (3GPP), advanced antenna design significantly improves the wireless communication qualities. However, limited number of researches have been published on how the smarter antenna design satisfies the 5G antenna design requirements. Hence, in this paper, we have shown that effective antenna designing techniques achieve substantial antenna performance enhancements that are essential input for the current and next-generation communication engineering. First, the excitation weights of the individual array elements are optimized to obtain enhanced antenna performances including reduced side lobe level (SLL), high directivity, reduced power consumption, and flexible radiation pattern. Then, a novel SLL attenuation technique is introduced to further reduce the SLL, power wastage, and interference. In general, the proposed technique of radiation pattern synthesis has resulted in to much better SLL reduction, directivity improvement, power wastage and interference reduction.
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Papers by Dawit Hadush Hailu