WiMAX Service Research Articles

Drone Shaped Fractal Antenna with Defected Ground Structure for RF Energy Harvesting Applications

A proposed multiband drone shaped fractal antenna (Antenna-1) is introduced in this paper that targets the most required frequencies used for radio frequency energy harvesting applications, including WLAN-2.4G, WLAN-5G, WLAN-6G, Mobile DCS1700, Mobile LTE and WIMAX services. A novel fractal shape is designed and combined with a standard square geometrical shape in order to implement the front patch of the antenna. The antenna is simulated with CST Studio Suite software and fabricated on FR-4 substrate. Different antenna stages with parametric study and optimization were implemented to get the best performance from the drone shape fractal antenna. The multiband (Antenna-1) supports six resonate frequencies (1.7155 GHz, 2.424 GHz, 3.36 GHz, 3.789 GHz, 5.843 GHz, 6.886 GHz) with peak gain of (2.83 dBi) at the frequency 2.45 GHz and a maximum bandwidth of (0.4281 GHz) at the frequency 5.8 GHz that make it a suitable antenna for radio frequency energy harvesting applications.

Design and analysis of metamaterial inspired multiband, high gain superstrate patch antenna for military applications, WiMAX, and maritime mobile services

Design and analysis of metamaterial inspired multiband, high gain superstrate patch antenna for military applications, WiMAX, and maritime mobile services

A hybrid bandwith allocation algorithm for EPON-WiMAX integrated networks based on auction process

Integration of Ethernet passive optical network and WiMAX technologies is viewed as a great solution for next-generation broadband access networks. In the systems adopting this strategy, weighty bandwidth allocation schemes are fundamental to fulfill the quality of service and fairness requirements of different traffic classes. Existing proposals to overcome the bandwidth allocation problem in EPON/WiMAX networks dismiss collaboration between the self-interested EPON and WiMAX service providers. This study presents a novel EPON-based semi-dynamic bandwidth allocation algorithm to allow the integration process. In the proposed algorithm depending on the auction process, the optical line terminal runs an auction to adequately post the optical network unit bandwidth that distributes the most elevated bidders based on the measurement of the accessible bandwidth. Simulation results demonstrate massive upgrades compared with fair sharing using dual-service-level agreements, limited-service interleaved polling with adaptive cycle time methods, bandwidth allocation strategy using Stackelberg game, and bandwidth allocation strategy using coalition game regarding the quality of service parameters such as throughput and time delay. This will be extremely helpful for optical system upgrading and improvement with minimal effort.

Design of MIMO Antenna with an Enhanced Isolation Technique

The isolation between the microstrip patches has a great significance to examine the performance of the multiple-input-multiple-output (MIMO) antennas. The patch antennas are placed on the top of 1.46 mm thick Rogers RO3003 substrate having a length of 60 mm, a width of 50 mm, and relative permittivity of 3. The distance between the resonators is 0.06λ and they are stimulated by two coaxial probes extended from the bottom ground layer. The defective ground structure of the H-shape slot is inserted on the bottom ground layer to achieve high isolation (mutual coupling reduction). The proposed MIMO antenna operates at 5.3 GHz frequency, which can be used for WiMAX, Wi-Fi, and future 5G services all over the world. The results of the designed structure have been simulated in a finite element method-based solver high-frequency structure simulator (HFSS). The simulated results show that the reflection coefficient (S11) and isolation (S21) at the desired frequency are −32 dB and −41 dB, respectively.

Assessment of Electromagnetic Radiation from Base Station Antenna

In order to study the high level of non-ionizing electromagnetic radiation near base station antennas, the present paper deals with the study of amount of electromagnetic radiation in the close vicinity of the antennas installed for various communication purposes. Equivalent isotropically radiated power calculations have been done for the selected communication site. At this site; GSM, CDMA, 3G/UMTS, and WiMAX services are being offered. For this site, the overall ratio of EIRP and threshold EIRP combining all services has been calculated at ground level (0.0175123), and nearby buildings (0.0089344, 0.0089344, 0.0089344, 0.0089344). Calculation study revealed that the ratio of EIRP and threshold EIRP is less than unity and thus the particular site is normally compliant and does not impose any adverse health effects.

A printed expanded graphite paper based dual band antenna for conformal wireless applications

A flexible paper based and dual-band antenna is designed for UMTS service (1.9 GHz) and WiMAX services (5.8 GHz). Flexible paper is used as a substrate for the printed antenna. Expanded graphite ink is used to enable printing the antenna on the substrate. The antenna has been designed, simulated, fabricated, and measured. Steps of preparing the conductive printed ink and fabrication of the antenna have been discussed. The conductivity of the printed antenna is measured to be 1 × 104 S/square and the thickness is also measured with an average of 30 µm. Through the whole paper, good agreement between simulated and measured results is satisfied. In addition to the achieved flexibility, the antenna has demonstrated good measurement results. First, the antenna has a bandwidth of 300 MHz at 1.9 GHz and 400 MHz at 5.8 GHz with fractional bandwidth of 15.7% and 6.8% at the both bands, respectively. Second, the measured antenna radiation pattern has indicated that it is omnidirectional at 1.9 GHz and approximately omnidirectional at 5.8 GHz. Third, The antenna gain is 1.266 dB and 0.512 dB at the two bands, respectively. Finally, the antenna’s efficiency at the both bands is 35% and 55%.

A Quad-Band Dual-Sense Circularly-Polarized Square-Ring Antenna for Multi-Functional Wireless Applications

A quad-band dual-sense circularly-polarized (CP) antenna is presented for multi-functional wireless applications. Initially, the corner-fed square-ring radiator is designed with one end open-circuited. The surface currents flow along the circumference of the square-ring, which excite dual-band dual-sense CP radiation with a right-hand circular polarization (RHCP) at one frequency band and a left-hand circular polarization (LHCP) at the other band. Later, a rhombic-shaped slot and an inverted V-shaped parasitic element, used to balance the surface currents in horizontal and vertical directions at the middle and low frequency regions, excite two additional LHCP bands. The proposed antenna is systematically presented through a CP generation principle, a surface current distribution, and parametric analysis. The measured results yield an impedance bandwidth (IBW) of 83.9% (2.33–5.70 GHz) and the 3-dB axial ratio bandwidths (ARBWs) of 7.3% (2.38–2.56 GHz), 9.0% (2.75–3.03 GHz), 3.7% (3.42–3.53 GHz), and 7.1% (5.16–5.54 GHz). The maximum broadside gains achieved within the axial ratio bandwidths are 2.5, 2.9, 3.4, and 2.7 dBi, respectively. Compared to other reported works considering quad-band CP radiation, the proposed antenna achieves a wider ARBW and smaller size. To the best of the author’s knowledge, the proposed work is the first paper presenting a planar quad-band dual-sense CP antenna for WLAN (2.5/5.3 GHz), WiMAX (3.5 GHz), and Marine Service (3.0 GHz) wireless applications.

Performance Investigation of VoIP Over Mobile WiMAX Networks through OPNET Simulation

Worldwide Interoperability for Microwave Access (WiMAX) is regarded as a promising technology that can provide wireless communication because of its advantages which include, high-speed data rates, high coverage and low cost of development and maintenance. WiMAX also supports the performance of Voice over Internet Protocol (VoIP), which is expected to replace conventional circuit switched voice services. VoIP requires to accurately design of QoS configurations over WiMAX networks. This paper focuses on studying and analyzing the performance of VoIP over WiMAX mobile networks. WiMAX network and VoIP technology such as mobility, WiMAX service classes, number of nodes and VoIP codecs are studied and analyzed. WiMAX network is simulated in a different manner using the simulation program known as OPNET Modeler. Simulation results established that the service layer Unsolicited Grand Service (UGS) is more appropriate for VoIP service because it has the best standard and performance. It was also observed that the least delay and highest value of customer satisfaction rate of services is demonstrated by the G.723.1 best coding. It also maintains the minimum consumption of capacity.

P1: Competing in the Broadband Service Industry

In 2008, Packet One Networks (Malaysia) Sdn. Bhd., or P1, launched its Worldwide Interoperability for Microwave Access (WiMAX) service, P1W1MAX, in Kuala Lumpur. This event kicked off the company's pioneering effort to provide Malaysians with WiMAX wireless broadband access, which it promised to be a better alternative to the current wired and 3G broadband offerings. Within a year, it had built a customer base of about 80,000 subscribers, and achieved an average revenue per user of about RM89 (approximately US$30). One year later, the company rolled out its Sudah Potong (Cut Already) marketing campaign and by the end of 2010, it had gathered about 280,000 customers and its ARPU of RM72 was among the highest in the industry. P1's five-year, three-phase plan (2007–2012) involving an investment of RM1 billion (about US$330 million) for the development of its WiMAX services, aimed to reach 65% area coverage throughout Malaysia by 2012. In December 2010, it announced its goal to increase its customer base to 450,000 by the end of 2011 to achieve its planned break-even. These efforts, however, attracted increased attention from the public, and even more so from its industry rivals, which reacted aggressively to P1's expansion. P1's top management knew that the company needed to act quickly, especially since the company's breakeven target date had reportedly been deferred several times. This case provides a scenario that can stimulate discussion on business strategies to be pursued by the top management of a growing firm operating in a very competitive industry.

Performance Analysis of the Impact of the Propagation Environments on the WiMAX Service Classes

Performance Analysis of the Impact of the Propagation Environments on the WiMAX Service Classes

Editorial for Special Issue on “Advances on Vehicular Communication Systems”

Editorial: The joint efforts of academia and industry in the past years have led to the introduction of new on board applications and services. In addition, governments and standardization organizations have agreed upon a common set of standards (DSRC) specific to vehicle-tovehicle (V2V) and vehicle-to-infrastructure (V2I) communications. Combined with the cellular network infrastructure, they pave the way for a plethora of solutions empowered by vehicular communications. Among these solutions, we have emergency alerts, autonomous vehicles, infotainment, comfort services, cooperative road sensing and collaborative applications. Also, the integration between smartphones and vehicles has been addressed by many researchers, and a wide range of applications are already available, many more being expected. In terms of communication systems, mobility effects and channel conditions heavily affect the signal quality, introducing path-loss, fading, and received power fluctuations. Under such conditions, several issues remain open including message dissemination in congested environments, Quality of Service (QoS), efficient and adaptive routing, MAC layer enhancements, mobility prediction, efficient handovers, etc. For this special issue we have selected 6 high-quality papers among a total of 26 submissions. The first article, entitled “Implementation and Performance Evaluation of Distributed Autonomous Multi-Hop Vehicle-to-Vehicle Communications over TV White Space” by K. Tsukamoto et al., presents a two-layer control channel model able to establish the multi-hop network. In their proposal, the vehicles construct a swarm using location and direction information, while sharing route and channel information. The vehicles use GPS-driven oscillators for coarse synchronization, introducing a time margin to accommodate for the remaining drift. Simulation results show that the proposed idea is suitable for vehicular environments, providing efficient and stable V2V communication. The second article, entitled “Safety enhancement and Carbon Dioxide (CO2) reduction in VANETs” by A.F. Santamaria et al., discusses new approaches for road safety. In particular, the authors illustrate a novel cooperative architecture supporting both V2V and V2I connectivity. The idea, called SeAWave, takes advantage of the IEEE802.11p standard, enhancing it by adding useful messages to improve the vehicles’ active and passive safety systems based on information about the environment and road conditions. Simulations show good results for the proposed smart traffic management system. The third article, entitled “Target RSU Selection with Low Scanning Latency in WiMAX-enabled VANETs” by S.H. Ahmed et al., addresses the problem of handover management in VANETs, exploiting the potentialities of WiMAX services when users switch between C. T. Calafate (*) : P. Fazio Technical University of Valencia, Valencia, Spain e-mail: calafate@disca.upv.es

Information about Simulation Software for Testing of Wireless Network

Actual network testing is time consuming and costly for researcher so Solution for this problem is that to test wireless network using open source and free software is available for that .The paper reflects the number of software availability to network model design and its performance . Many authors have worked on various QoS parameters using different service classes in WiMAX. WiMAX is wireless technology for fixed and mobile access and also known by IEEE802.16 standard .Now a day’s WiMAX is fast and suitable wireless technology for urban and rural area which can cover maximum area with minimum infrastructure. IEEE 802.16e-2005 has been developed for mobile wireless communication which is based on OFDM technology and this enables going towards the 4G mobile in the future. In this paper, simulation model based on 802.16e OFDM-PHY baseband (WIMAX) and demonstrated in simulation scenarios with QPSK to find out the best performance of physical layer for WiMAX Mobile. All the necessary conditions were implemented in the simulation according to the 802.16e OFDMA-PHY specification. The study is conducted on various quality parameters impacting the WiMAX service performance of a WiMAX network and also introduces NS3 simulation software to test WiMAX network.

CINR Performance of Downlink Mobile WiMAX IEEE 802.16e Deployed Using Coexistence Cellular Terrestrial and HAPS

Deploying WiMAX through High Altitude Platform Station (HAPS) system is a new means of wireless delivery method and thus attracting much the attention in a telecommunication society. However delivering WiMAX through the terrestrial network has already been started a few years ago. Therefore, we need to look at the scenario of coexistence system both of HAPS and terrestrial in delivering WiMAX services. This paper evaluates the performance of coexistence system between cellular HAPS and terrestrial for the downlink scenario when they are transmitting WiMAX mobile 802.16e services. Our evaluation is based on the performance simulation of coexistence model using two methods. First method is a footprint exchange between the two systems.The second method is a combination of footprint exchange and HAPS footprint enhancement. The proposed methodsare then evaluated by computer simulation in terms of carrier to interference plus noise ratio (CINR) performance. In general, both methods resulting performance enhancement in CINR quality compared with coexistence deployment with normal scenario of the cell configuration used by HAPS and terrestrial. The method of combining footprint exchange and HAPS footprint enhancement is able to improve CINR more than 10 dB compared with the normal footprint configuration for all users location inside the coverage.

An Adaptive Weight Calculation based Bandwidth Allocation Scheme for IEEE 802.16 Networks

WiMAX standard also known as IEEE 802.16 is a wireless MAN standard driven by WiMAX Forum. WiMAX forum defines specification for QoS provisioning for manufacturing of WiMAX equipment by different vendors but the amount of bandwidth allocated to specific service in WIMAX is still an open issue. A number of algorithms have been presented to satisfy the diverse QoS requirements for traffic in WiMAX networks. The focus of all these algorithms is towards real time traffic. Non real time traffic like nrtPS and BE is quite often neglected. This paper is an attempt towards fair allocation of resources to non real time traffic simultaneously taking care of real time traffic also. The approach uses uncertainty principles of fuzzy logic to calculate new weights for different flows and makes allocation based on these new weights. Simulation results show that the proposed scheme was able to meet required performance levels for both kinds of traffic.

Radio-Over-Fiber Access Architecture for Integrated Broadband Wireless Services

This paper introduces two radio-over-fiber (RoF) architectures for the future broadband optical-wireless access network-all-band RoF and band-mapped 60-GHz RoF that can be integrated in ultra-dense wavelength division multiplexing passive optical network (UDWDM-PON). Legacy wireless services and multi-gigabit millimeter-wave (mm-wave) applications are integrated and delivered simultaneously under one shared infrastructure. With centralized system control and signal processing, the proposed systems provide cost-effective and protocol-transparent solutions for the next-generation multi-service bundle in heterogeneous networks (HetNets). In the all-band RoF network where wireless services are kept at their original carrier frequencies, Wi-Fi, WiMAX, and 60-GHz high-speed mm-wave services are transmitted based on subcarrier multiplexing (SCM) and dual-wavelength heterodyne beating techniques in avoidance of optical filters and large-bandwidth optoelectronic components. In the indoor environment, the band-mapped mm-wave RoF design is illustrated with real-time analog television signal, Wi-Fi, and high-speed digital baseband data-all of which are transmitted over unified optical and air links. By mapping various wireless signals into 60-GHz sub-bands, the novel architecture achieves higher spectral efficiency and lower power consumption.

Analyzing the Integration of WiMAX and Wi‐Fi Services: Bandwidth Sharing and Channel Collaboration

ABSTRACTSeveral emerging studies have focused on the pricing issue of bandwidth sharing between Wi‐Fi and WiMAX networks; however, most either concentrate on the design of collaborated protocols or figure out the issue without the overall consideration of consumer preferences and contract design. In this study, we explore a wireless service market in which there are two wireless service providers operating Wi‐Fi and WiMAX. One of the research dimensions given in this study is whether wireless service providers implement bandwidth sharing, while the other is whether they make decisions individually or jointly. By involving consumer preferences and a wholesale price contract in the present model, we find that bandwidth sharing would benefit a WiMAX service provider, yet a Wi‐Fi service provider would make no significant savings under a wholesale price contract. In addition, the profit of a WiMAX service provider may increase with Wi‐Fi coverage when bandwidth sharing has been implemented but decrease with Wi‐Fi coverage when both wireless services operate without bandwidth sharing. Furthermore, the WiMAX service provider allocates more capacity when the average usage rate increases, but lowers the expenditure of capacity when the average usage rate is too high.

Triple Band Annular Ring Loaded Stacked Circular Patch Microstrip Antenna

In this paper a novel structure of annular ring loaded stacked circular patch microstrip antenna is theoretically analysed to observe various parameters such as return loss, input impedance, gain, directivity and radiation pattern. It is found that antenna possess three band of operation which signify the compactness and multiband operation of antenna. The antenna is resonating at three operating frequencies 1.720, 2.950, 3.060 GHz. The proposed theory is verified by simulation using Ansoft's HFSS and theoretical results are in good agreement with simulated results. The antenna is useful for multi-services operations such as WLAN, GSM, UMTS, and WiMAX services.

Novel user centric, game theory based bandwidth allocation mechanism in WiMAX

AbstractBandwidth allocation plays a crucial role in ensuring overall quality of service in WiMAX. WiMAX supports non-contention based bandwidth allocation mechanism, where the responsibility of bandwidth allocation lies with the base station. In this paper, a novel user- centric, Game Theory-based bandwidth allocation algorithm is proposed. The Users/Mobile Station shall be grouped in pairs and bandwidth allocation is performed alternately between the two users of a group. In any given frame only one user from a pair is allocated bandwidth. The bandwidth thus allocated shall satisfy the requirements of the user/mobile station for two consecutive frames. Since, in any given frame, only one user/MS is allocated the bandwidth, the proposed algorithm reduces the frame overhead, thereby saving precious bandwidth that can be utilized to improve throughput. Simulation results show a 50% decrease in the uplink frame overhead and about 8% improvement in the uplink throughput per user/mobile station.

Cross‐layer channel selection and reward‐based power allocation for increasing system capacity and reward in multiple‐input–multiple‐output wireless communications

For increasing network bandwidth and guaranteeing quality of service in WiMAX, IEEE 802.16 m proposes the multiple-input–multiple-output (MIMO) technique that offers compatible specifications with the existing IEEE 802.16 family specifications. However, the performance of the IEEE 802.16 MIMO specification is significantly degraded in the high-mobility environment and high communication interference. As a result, a sender easily uses inaccurate modulation and coding scheme (MCS) and improper power allocation for different-priority users having different received signal-to-noise ratios. The system capacity is thus affected significantly. Additionally, the multiuser MIMO systems seldom consider that different-priority users and different-class traffic bring different rewards to the system. This study thus proposes a cross-layer reward-based approach (namely CLR) that consists of three schemes: adaptive modulation and coding determination, cross-layer dynamic channel selection, and reward-based weighting power allocation. The proposed CLR approach achieves accurate channel state information determination, optimal channel selection, and adaptive reward power allocation. Numerical results demonstrate that the proposed approach significantly outperforms the other approaches in system reward, system capacity, and the accuracy of the MCS determination.

Priority Based Uplink Scheduling Scheme for WiMAX Service Classes

IEEE 802.16 standard supports five different service classes in order to support different needs of the mobile users with different QoS criteria. But, this standard doesn't specify admission control and scheduling mechanisms and so far many solutions are proposed in the science world. In this paper we propose priority based uplink scheduling scheme for IEEE 802.16 standard that improves the QoS performances of the five WiMAX service classes, especially of the ertPS service class. Simulation experiments and analysis are done choosing the most adequate WiMAX simulator and the ns-2 simulation tool. Traffic load of the ertPS connections is changed from low to high in order to perform detailed performance analysis of the results. Results given in average delay, average jitter and average throughput are evaluated and compared with so far known uplink scheduling mechanism. The results show that our proposed uplink scheduling scheme based on the priority of the service classes improves the QoS performances especially in high loaded scenarios.