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Publications (357)
On 4–8 December 2023, IEEE GLOBECOM 2023 unfolds with grandeur in the bustling city of Kuala Lumpur, the capital of Malaysia, welcoming more than 2,000 attendees among research scholars, industry experts, and governmental representatives worldwide.
Crosstalk among different orbital angular momentum (OAM) states, mainly caused by the atmospheric turbulence and the misalignment between the transmitting and receiving antennas, leads to the increase of error probability of OAM transmission systems. Considering the OAM-based multiple-input multiple-output (OAM-MIMO) transmission system with unalig...
This study focuses on the downlink (DL) transmission of massive multiple-input-multiple-output (MIMO) with the support of simultaneous wireless information and power transfer (SWIPT) system based on a power-splitting (PS) scheme. To reach the green design target in the concept of wireless communication networks, this paper maximizes the system's en...
Peatland is important to rural communities’ livelihood due to its potential for aquaculture and agriculture. Nonetheless, human activities such as slash-and-burn can greatly increase forest fire risk, which can release a great amount of greenhouse gases and carbon dioxide into the atmosphere. To sustainably manage and restore peatlands, the Interne...
Peatland forest fires are a serious threat to the biodiversity-ecosystem and to human health in South East Asia, especially in the dry season. Here, approximately 2.13 million hectares of peat swamp forests are found and made up of 6.5% of the total land area. However, monitoring and management of sustainable peat swamp forests can be improved, as...
In this paper, the power transmission and energy efficiency (EE) in downlink multi-cell massive multiple-input–multiple-output (MIMO) systems are investigated and optimized. Most of the existing works do not take into account different user quality of service (QoS) requirements. These models also depend on a fixed transmit power consumption, which...
With the development of wireless mobile communication technology, the demand for wireless communication rate and frequency increases year by year. Existing wireless mobile communication frequency tends to be saturated, which demands for new solutions. Terahertz (THz) communication has great potential for the future mobile communications (Beyond 5G)...
A cognitive radio sensor network (CRSN) is a solution that enables sensor nodes to opportunistically access licensed radio channels. Data transmitted over a network are divided into packets. In machine-to-machine communication, which is a heterogeneous nature of wireless networks, small-size packets are the common form of traffic. Due to the nature...
In many low-cost mobile device applications, the drawback of high crest factor (CF) may outweigh all the potential benefits of broadband communication systems. Orthogonal
frequency division multiplexing (OFDM) is considered to be one of the important multicarrier standards in broadband communication systems. However, high CF is the major problem of...
In 6LoWPAN, IPv6 packet’s fragments are forwarded using multi-hops route-over routing protocols. Although conventional route-over achieves high packet delivery ratio, it has high delay due to the hop-by-hop fragmentation and reassembly. Conversely, enhanced route-over reduces the delay through avoiding the hop-by-hop fragmentation and reassembly. H...
The 802.11e Task Group has established to enhance Quality of Service (QoS) provision for time-bounded services in the current IEEE 802.11 Medium Access Control (MAC) protocol. The QoS is introduced throughout Hybrid Coordination Function Controlled Channel Access (HCCA) for the rigorous QoS provision. In HCCA, the station is allocated a fixed Trans...
This paper presents a novel low complexity technique for reducing the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing systems followed by an efficient hardware co-simulation implementation of this technique by using a Xilinx system generator on field programmable gate array. Unlike the conventional scheme, the propo...
This paper presents a novel low complexity technique for reducing the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing systems followed by an efficient hardware co-simulation implementation of this technique by using a Xilinx system generator on field programmable gate array. Unlike the conventional partial transmit...
Article ID: JST-S0149-2016
Digital predistortion is one of the most widely used techniques to linearize a power amplifier (PA) to
reduce the error vector magnitude (EVM) distortion and spectral regrowth. By far, the lookup table (LUT)
predistorters are most frequently used scheme to mitigate the effects of non-linear power amplifier. In
this paper,...
Mobile operators currently encounter numerous challenges caused by the centralized architecture of mobile networks. A single mobility anchor placed at the network core maintains the entire mobility and data traffic forwarding in the existing centralized mobility management (CMM) solutions. The CMM approach confronts several issues in scalability, r...
In this paper, we propose a novel technique to reduce the crest factor (CF) in orthogonal frequency division multiplexing systems. It consists of two inverse fast Fourier transform (IFFT) blocks, the input symbols of the first IFFT are the mapped symbols, whereas the input symbols of the second IFFT are the summations of the absolute value of the r...
Efficiently scheduling various service classes while fulfilling performance targets is one of the main challenges in 3GPP Long-Term Evolution (LTE) communication systems. However, Quality of Service (QoS) and fairness provisioning for all different service classes are generally unstable due to insufficient radio resources, especially in heavily loa...
In Long Term Evolution-Advanced (LTEA) networks, different aspects of radio resource scheduling such as fairness and Quality of Service (QoS) assurance must be provided for heterogeneous traffic, having different characteristics. However, the ever-growing number of mobile devices sharing the limited radio resources leads to the high cost and diffic...
This paper presents a novel low-complexity technique for reducing the peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems followed by an efficient hardware co-simulation implementation of this technique by using a Xilinx system generator on a field programmable gate array (FPGA). Through the comparison of...
Agile-SD is one of the latest versions of loss-based congestion control algorithm (CCA), which has been proposed to improve the total performance of transmission control protocol (TCP) over high-speed and short-distance networks. It has introduced a new mechanism, called agility factor mechanism, which shortens the epoch time to reduce the sensitiv...
This article presents a Hybrid Latency Low handover mechanism for PMIPv6 wireless networks (HLL-PMIPv6). It aims to provide ubiquitous Internet access for mobile host with a high-speed mobility environment. The HLL-PMIPv6 introduces a new entity called, iHLMA, which is responsible to coordinate mobile host’s intra and inter handovers and maintains...
In Mobile WiMAX, a Base Station (BS) delivers security keys to Mobile Stations (MSs) through a key distribution scheme to guarantee security and access control. The MSs need to perform ciphering operations to access the keys upon rekeying process. In this way, the MSs consume energy to receive and decrypt the keys for further communication with a B...
Presents key events and topics in the global communications industry.
IEEE 802.11e standard introduces HCF Controlled Channel Access (HCCA) to support quality of service (QoS) for multimedia traffics. In HCCA, the traffics scheduled according to their mean characteristics which favors the Constant Bit Rate (CBR) trans- mission approach. However, it does not efficiently cope with the fluctuation of the Variable Bit Ra...
Coping with customer interests to employ Wireless Sensor Networks (WSN) in the new applications requires dealing with the fact of nodes variety that implies the heterogeneous nature of the traffic. This necessitates employing differentiation techniques that lead in the end to implementing prioritization in some processes of the system. The medium a...
The growing variety and consumption of the mobile services throughout the Long Term Evolution (LTE) mobile networks lead to various challenging issues in radio resource scheduling. One of the main challenges in LTE resource management is how to allocate the scare available bandwidth, especially in overload states of the network, to the services whi...
The inherent character of the Power Amplifier (PA) on its non-linearity causes unwanted amplitude and phase distortions at the PA output signal. Faster information transmission speed together with the rapid changes in temperatures of electrical components incurs Memory Effects, the undesired spreading of the PA output signal. Digital Pre-distortion...
In this paper, we propose a novel technique to reduce the crest factor (CF) in orthogonal frequency division multiplexing systems. It consists of two inverse fast Fourier transform (IFFT) blocks, the input symbols of the first IFFT are the mapped symbols, whereas the input symbols of the second IFFT are the summations of the absolute value of the r...
Opportunistic frequency-domain scheduling and link adaptation enable the long term evolution (LTE) cellular systems to maximize the throughput. Successful scheduling and link adaptation require perfect channel state information (CSI) at the eNodeB. However, for multi-carriers systems, a huge undesirable amount of signaling overhead is required to r...
In Cognitive Radio (CR), the conventional narrowband spectrum sensing requires either random channel sensing order or predefined channel sensing sequence to sense all channels in a specified spectrum band in order to detect vacant channels. This may be inefficient in energy constraint devices networks such as Cognitive Radio Wireless Sensor Network...
The rapid expansion of wireless monitoring and surveillance applications in several domains reinforces the trend of exploiting emerging technologies such as the cognitive radio. However, these technologies have to adjust their working concepts to consider the common characteristics of conventional wireless sensor networks (WSNs). The cognitive radi...
A low-complexity peak-to-average power ratio (PAPR) reduction scheme in an orthogonal frequency division multiplexing system is proposed. The proposed scheme utilizes a new phase sequence based on a gray code structure and a similarity measurement block. Due to the ordered phase sequences, a noteworthy reduction capacity is obtained in terms of the...
This study presents subblocks interleaving partial transmit sequence (SBI-PTS) technique having low complexity for reducing the peak-to-average power ratio in orthogonal frequency division multiplexing systems. In this technique, a new subblocks interleaver is proposed, in which each subblock is interleaved with the others. Moreover, a new optimisa...
As the initial scope of supporting communications inside substation automation systems, IEC 61850 was defined to be mapped on Ethernet as the layer 2 communication network technology. It is because the Ethernet is the dominant technology for the Local area network – LAN and it brings significant advantages of high bandwidth and low latency especial...
The 802.11E Task Group has been established to enhance Quality of Service (QoS) provision for time-bounded services in the current IEEE 802.11 Medium Access Control (MAC) protocol. The QoS is introduced throughout Hybrid Coordination Function Controlled Channel Access (HCCA) for the rigorous QoS provision. In HCCA, the station is allocated a fixed...
The IEEE 802.11e standard introduced by IEEE 802.11 Task Group E (TGe) enhances the Quality of Service (QoS) by means of HCF Controlled Channel Access (HCCA). The scheduler of HCCA allocates Transmission Opportunities (TXOPs) to QoS-enabled Station (QSTA) based on their TS Specifications (TSPECs) negotiated at the traffic setup time so that it is o...
Quality of Service (QoS) is provided in IEEE 802.11e protocol by means of HCF Controlled Channel Access (HCCA) scheduler which is efficient for supporting Constant Bit Rate (CBR) applications. Numerous researches have been carried out to enhance the HCCA scheduler attempting to accommodate the needs of Variable Bit Rate (VBR) video traffics which p...
IEEE 802.11e standard defines two Medium Access Control (MAC) functions to support Quality of Service (QoS) for wireless local area networks: Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). EDCA provides fair prioritized QoS support while HCCA guarantees parameterized QoS for the traffics with rigid QoS requirem...
Transmission Control Protocol (TCP) has been profusely used by most of internet applications. Since 1970s, several TCP variants have been developed in order to cope with the fast increasing of network capacities especially in high Bandwidth Delay Product (high-BDP) networks. In these TCP variants, several approaches have been used, some of these ap...
Recently, high-speed and short-distance networks are widely deployed and their necessity is rapidly increasing everyday. This type of networks is used in several network applications; such as Local Area Networks (LAN) and Data Center Networks (DCN). In LANs and DCNs, high-speed and short-distance networks are commonly deployed to connect between co...
The IEEE 802.11e standard introduced by IEEE 802.11 Task Group E (TGe) enhances the Quality of Service (QoS) by means of HCF Controlled Channel Access (HCCA). The scheduler of HCCA allocates Transmission Opportunities (TXOPs) to QoS-enabled Station (QSTA) based on their TS Specifications (TSPECs) negotiated at the traffic setup time so that it is o...
New mobility solutions are required for mobile environments characterised by an everincreasing
number of mobile devices and volume of internet data traffic. A single mobility
anchor in the current Centralised Mobility Management (CMM) performs all mobility and
routing functionalities. Distributed Mobility Management (DMM) paradigm is introduced
rec...
In LTE systems, multicast services must be delivered efficiently in response to the need for strong QoS support. However, each class of quality services has its own requirements to be satisfied. These quality constraints limit the scheduling flexibility, and the LTE downlink resource allocating algorithms need to assimilate these con- straints whil...
To enhance network performance, PHY and MAC layer has direct influence besides other factors as these are major layers of OSI based communication system. One way of enhancing network performance is the managing the radio resources intelligently. As cross layer based systems might be faster responding in case of network resource distribution and due...
Mobile network operators urgently need to scalable and reliable mobility management solutions to cope with the explosive increase of the mobile users and internet traffic. Although the network-based PMIPv6 protocol is considered the favorable solution to solve the problems of host-based MIP protocol, these protocols are based on centralized mobilit...
The development of a computational platform of a communication network for an automation system using the precepts of IEC 61850 has become a great trend in substation automation systems (SASs) research. Recent developments in wireless communication technologies, especially the IEEE802.11 have enabled cost-effective remote control systems with a cap...
The frequency domain scheduling gain can be maximized when precise channel information is available at the eNodeB for the whole bandwidth. To compensate for the continuous variations of channel conditions in time and frequency domains, a huge undesirable amount of signaling overhead is required to report the channel quality indicator (CQI). On the...
To satisfy the demand for higher data rate while maintaining the quality of service, a dense long-term evolution (LTE) cells environment is required. This imposes a big challenge to the network when it comes to performing handover (HO). Cell selection has an important influence on network performance, to achieve seamless handover. Although a succes...
It is well-known that clustering partitions network into logical groups of nodes in order to achieve energy efficiency and to enhance dynamic channel access in cognitive radio through cooperative sensing. While the topic of energy efficiency has been well investigated in conventional wireless sensor networks, the latter has not been extensively exp...
High data rates in long-term evolution (LTE) networks can affect the mobility of networks and their performance. The speed and motion of user equipment (UE) can compromise seamless connectivity. However, a proper handover (HO) decision can maintain quality of service (QoS) and increase system throughput. While this may lead to an increase in comple...
IEEE 802.11e standard defines two Medium Access Control functions to support Quality of Service (QoS) for wireless local area networks: Enhanced Distributed Channel Access (EDCA) and HCF Controlled Channel Access (HCCA). EDCA provides fair prioritized QoS support while HCCA guarantees parameterized QoS for the traffics with rigid QoS requirements....
The deployment of different types of wireless technologies led to additional challenges to the issue of mobility management in next generation wireless networks. In addition to the regular movement of the mobile users in a heterogeneous environment, users’ demand for more real time services results in more handover complexity. Even though the netwo...
Orthogonal frequency division multiplexing systems suffer from one main drawback which is a high peak-to-average power ratio (PAPR) that leads to power efficiency degradation and when feed to a power amplifier operating in the nonlinear region yields adjacent channel interference and inferior bit error rate performance. There are many methods to ov...
Peak to average power ratio (PAPR) is one of the main imperfections in the broadband communication systems with multiple carriers. In this paper, a new crest factor reduction (CFR) scheme based on interleaved phase sequence called Dummy Sequence Insertion Enhanced Partial Transmit Sequence (DSI-EPTS) is proposed which effectively reduces the PAPR w...
The drawbacks of centralized mobility management (CMM) schemes, such as scalability, non-optimal routes, and single points of failure, led to the development of a distributed mobility management (DMM) scheme. The new DMM paradigm proposes a flatter system by moving the mobility functionalities closer to the user and distributing the control and dat...
The 802.11E Task Group has been established to enhance quality of service (QoS) provision for time-bounded services in the current IEEE 802.11 medium access control protocol. The QoS is introduced throughout hybrid coordination function controlled channel access (HCCA) for the rigorous QoS provision. In HCCA, the station is allocated a fixed transm...
Over the past few years, the wireless mesh network (WMN) with a multi-radio multi-channel (MR-MC) has attracted increasingly high attention because of its wider coverage area. The use of multiple radios and the function of multi-hop forwarding allows WMN to achieve a greater capacity and coverage area. MR-MC can be used to utilize the radio spectru...
Due to no feedback process and simplicity in searching algorithm, conventional selected mapping (CSLM) is an efficient crest factor reduction (CFR) technique in orthogonal frequency division multiplexing (OFDM) systems. However high number of inverse fast Fourier transform (IFFT) block is required to achieve the desired PAPR reduction performance....
Wireless Mesh Network (WMN) has recently emerged as a costeffective solution for the next generation ofWireless Networking. It has the potential to be widely deployed and widely used by Internet Service Providers (ISPs) worldwide. Unfortunately, current standards and protocols are severely inadequate to achieve the architectural design goals of wir...
In 6LoWPAN, IPv6 is capable to provide identity and wireless embedded internet aims for efficiently providing IP global connectivity for wireless, small size, low power, low rate, limited memory and limited computation capabilities embedded smart objects. However, the relatively huge header size of upper layer protocols (e.g. TCP, UDP and IPv6) wil...
This paper presents the application of IEC 61850 protocol in electrical power engineering industry for data communication systems between substations. This IEC 61850 protocol presents new challenges for real-time communication performance between Intelligent Electronic Devices (IEDs) within substation because of the Generic Object Oriented Substati...
Over recent years, enormous amounts of research in wireless sensor networks (WSNs) have been conducted; this is because of its multifarious applications such as in environmental monitoring, object tracking, disaster management, manufacturing, monitoring and control. Nevertheless, optimising the energy consumption of sensor nodes (SNs) in WSNs and r...
The idea of multiple antenna arrays has evolved into multiple-input multiple-output (MIMO) system, which provides transmit and receive diversities. It increases robustness of the effect of multipath fading in wireless channels, besides yielding higher capacity, spectral efficiency and better bit error rate (BER) performance. The spatial diversity g...
Energy efficient spectrum sensing and data
communication to extend the lifetime of cognitive radio sensor
network is becoming increasingly important due to resource
constraint of CR-WSN inherent from WSN. This paper presents
an energy-aware clustering (EAC) algorithm that enhances
spectrum sensing performance and reduces network energy
consumption...
Multicast IPv6 is an efficient way of transmitting data simultaneously to a group of IPv6 users. It has the advantage of reducing the required bandwidth of IPv6 data delivery compared to unicast transmission. The data rate of multicast transmission over WLAN is confined by the user with the lowest rate in the multicast group, which is called the fi...
Supporting visual data applications in the real-time communication systems are among the most challenging issues over the next generation wireless communication systems. This challenge is further magnified by the fact that the quality of reception is highly sensitive to transmission delay, data losses and bit error rate (BER) in such applications....
Enhanced partial transmit sequence (EPTS) and cross-correlation-PTS are two techniques for reducing peak-to-average power ratio (PAPR) in orthogonal frequency division multiplexing (OFDM) systems. EPTS is a low complexity technique compared to conventional partial transmit sequence (CPTS) and cross-correlation-PTS techniques which outperforms the c...
Power Efficiency in Broadband Wireless Communications focuses on the improvement of power efficiency in wireless communication systems, especially of mobile devices. Reviewing cutting-edge techniques for conserving power and boosting power efficiency, the book examines various technologies and their impact on consumer devices. It considers each tec...
IPv6 Low-power Personal Area Networks (6LoWPANs) have recently found renewed interest because of the emergence of Internet of Things (IoT). Mobility support in 6LoWPANs for large-scale IP-based sensor technology in future IoT is still in its infancy. The hospital wireless network is one important 6LoWPAN application of the IoT, it keeps continuous...