Broadband Wireless Access

In 2020, mobile access networks will experience significant challenges as compared to the situation of today. Traffic volumes are expected to increase 1000 times, and the number of connected devices will be 10-100 times higher than today in a networked society with unconstrained access to information and sharing of data available anywhere and anytime to anyone and anything. One of the big challenges is to provide this 1000-fold capacity increase to billions of devices in an affordable and sustainable way. Low energy consumption is the key to achieve this. This paper takes as starting point the situation of today, and tries to pinpoint important focus areas and potential solutions when designing an energy efficient 5G mobile network architecture. These include system architecture, where a logical separation of data and control planes is seen as a promising solution; network deployment, where (heterogeneous) ultra dense layouts will have a positive effect; radio transmission, where the introduction of massive antenna configurations is identified as an important enabler; and, finally, backhauling solutions that need to be more energy efficient than today.

Seamless handover in wireless networks is to guarantee both service continuity and service quality. In WiMAX, providing scalability and quality of service for multimedia services during handover is a main challenge because of high latency and packet loss. In this paper, we created four scenarios using Qualnet 5.2 Network Simulator to analyze the hard handover functionality of WiMAX under different conditions. The scenarios such as Flag with 5 and 10 sec UCD and DCD interval values, Random mobility scenario and DEM scenario using 6 WiMAX Cells have been considered. This study is performed over the real urban area of JNU where we have used JNU map for scenarios 1, 2 and 3 but for scenario 4, the JNU terrain data has been used. Further, each BS of 6 WiMAX cell is connected to four nodes. All nodes of each scenario are fixed except Node 1. Node 1 is moving and performing the handover between the different BSs while sending and receiving real time traffics. Flag mobility model is used in Scenario 1, 2 and 4 to model the movement of the Node 1 while we use random mobility model in sceanrio3. 5 seconds time interval is used for Scenarios 1, 3, and 4 while 10 seconds time interval is used for scenario 2 to study the effect of management messages load on handover. Further, the statistical measures of handover performance of WiMAX in terms of number of handover performed, throughput, end-to-end delay, jitter, and packets dropped are observed and evaluated.

Smart antennas enable space division multiple access, that is they manage access to a network by accounting for where users are spatially and using antenna technology to better isolate signals from noise and interference. For mobile systems, the benefits are increased capacity from existing cell sites, maximum return on infrastructure investment, and improved network efficiency and performance. In mobile systems, all the benefits for base-to-mobile and mobile-to-base paths occur as a result of smart antennas being installed at the base site. For fixed wireless systems, smart antennas are practical for both the base station and the remote station (RS). This paper discusses the increase in throughput that is realized by using smart antenna technology in a fixed wireless system. The management of packet transmission and reception, a key component of maximizing capacity, is described. Also included is a discussion of the user benefits and capacity impact of smart antennas at a remote station.

The delivery of Voice, Video and Data has transformed in the last number of years with the migration from co-axial trunks to fibre delivery and major protocol shifts, in the background from Asynchronous Transfer Mode (ATM) to Internet Protocol (IP). Telephone/fax line at the customer residence changed to Integrated Services Digital Network (ISDN) then to Asynchronous Digital Subscriber Line (ADSL), which is changing to Gigabit Passive Optical Network (GPON) and Gigabit Ethernet Passive Optical Network (GEPON). During this migration a major group of consumers, particularly those living in rural areas have been left to rely on Wireless solutions to provide access to services. To meet with the speeds that urban networks receive Wireless Internet Services Providers (WISP) and Mobile Operators need imaginative solutions to deliver services.
While traditional carriers like Eircom have tended to leverage their existing telephone networks by offering ADSL, the limited range of this technology has left gaps in coverage. In Ireland, in particular the timing of the sale of Eircom has left the country with a patchy broadband deployment based on the new owner’s commercial interests. Community broadband schemes using Wireless Local Area Networks (WLAN) solutions evolved into a patchwork of Wireless Internet Service Providers (WISP) upon which the mobile operators have layered what can be accurately described 3G midband to close the difference.
In this white paper the author looks at the solutions used currently for wireless provision of Internet Access. He also discusses at Long Term Evolution (LTE) and Wireless MAX (WiMAX), two solutions vying to provide wireless broadband for the future.

Many advanced data services are driving up wireless technology, which is further boosted by growth in advanced market segments. The wireless industry is evolving from a Web of independent networks into a single integrated network with multiple standards; the expectation is that WI-FI, WI-MAX and 3G will coexist to enable a host of exerting new applications and business models. This paper focuses on concepts of WI-MAX technology, which employs microwave for the transfer of data wirelessly, and it also presents its comparison with WI-FI, and 3G technologies. WI-MAX is delivering broadband wireless access to the masses and represents alternative to digital subscriber lines (DSL) and cable broadband access. WI-MAX is based on IEEE 802.16 standard and is scalable. It stands for wireless (WI) microwave access (MAX). WI-MAX will provide anywhere, anytime connectivity. Features of WI-MAX are OFDM i.e. orthogonal frequency division multiplexing, sub channelization, directional antennas and adaptive modulation, which make WI-MAX as the technology of today. The Benefit of WI-MAX technology is that the signals can be run very close to each other on wireless channels. Super narrow lanes can put a lot of traffic over them without disturbance. Many technologies currently available can only provide line of sight (LOS) coverage; the technology behind WI-MAX has been optimized to provide excelled non-line of sight (NLOS) coverage.

Wireless access networks today consume 0.5 percent of the global energy. Rapidly growing demand for new services and ubiqutious connectivity, will further increase the energy consumption. This situation imposes a big challenge for mobile operators not only due to soaring cost of energy, but also increasing concern for global warming and sustainable development.

This thesis focuses on the energy efficiency issue at the system level and studies how to incorporate energy-awareness into the design of future wireless access networks. The main contributions have been given in the areas of energy efficiency assessment, architectural and operational solutions, and total cost of investment analysis.

The precise evaluation of energy efficiency is the first essential step to determine optimized solutions where  metrics and models constitute the two key elements.
We show that maximizing energy efficiency is not always equivalent to minimizing energy consumption which is one of the main reasons behind the presented contradictory and disputable conclusions in the literature. Further we indicate that in order to avoid the debatable directions, energy efficient network design problems should be formulated with well defined coverage and capacity requirements. Moreover, we propose novel backhaul power consumption models considering various technology and architectural options relevant for urban and rural environments and show that backhaul will potentially become a bottleneck in future ultra-high capacity wireless access networks.


Second, we focus on clean-slate network deployment solutions satisfying different quality of service requirements in a more energy efficient manner. We identify that the ratio between idle- and transmit power dependent power consumption of a base station as well as the network capacity requirement are the two key parameters that affect the energy-optimum design.
While results show that macro cellular systems are the most energy efficient solution for moderate average traffic density, Hetnet solutions prevail homogeneous deployment due to their ability to increase the capacity with a relatively lower energy consumption and thus enable significant energy savings in medium and high capacity demand regions.
%Considering the fact that orders of magnitude of more mobile data traffic will be generated at indoors in the near future, \emph{blasting the signals over the walls} is neither energy efficient nor feasible to satisfy the growing capacity demand.
Moreover, we investigate the energy saving potential of short-term energy aware management approach, i.e., cell DTX, taking advantage of low resource utilization in the current networks arising from strict QoS requirements. With the help of developed novel quantitative method, we show that Cell DTX  brings striking reduction in energy consumption and further savings are achievable if the networks are designed taking into account the fact that network deployment and operation are closely related.

Finally, we develop a general framework for investigating the main cost elements and for evaluating the viability of energy efficient solutions.
We first reveal the strong positive impact of spectrum on both energy and infrastructure cost and further indicate that applying sustainable solutions might also bring total cost reduction, but the viability highly depends on unit cost values as well as the indirect cost benefits of energy efficiency.

Results obtained in this dissertation might provide guidelines for the network designers to achieve future high-capacity and sustainable wireless access networks.

Abstract—The telecommunication industry has been through disruptive times, but data networking service revenue has continued to rise. The telecom industry is expected to continue to grow as demand increases for cable and high-speed Internet in previously unserviced locations ...

Wireless broadband technologies provide ubiquitous broadband access to wireless users, enabling services that were available only to wireline users. In this paper, we summarize emerging wireless broadband access technologies, ranging from WLANs to satellite communications.,We explain the latest standards,in the IEEE 802.11 and IEEE 802.16 families in detail. The MAC layer mechanisms of IEEE 802.11e, 802.11n, and 802.11s standards

The demand for high-speed services and multimedia applications anywhere and anytime has led to the rise of wireless communications. In particular, WiMAX technology is nowadays considered one of the most prominent solutions capable to provide a Broadband Wireless Access ...

In this paper we are concerned with broadband wireless access via high altitude platform system, providing the Internet access and broadband multimedia services to passengers equipped with WLAN terminals connecting through a collective terminal mounted on the train. The main challenge in such scenario is the development of efficient and reliable radio interface for the broadband communication link in the mobile wireless access segment. We are focusing on performance analysis of the adaptive coding and modulation scheme in the communication link between a high altitude platform and a collective terminal on-board moving train. In order to increase the reliability of the communication system in a fading environment we also exploit space and platform diversity. The proposed approach significantly increases the throughput of the wireless access system, while bit error rate remains below the target value regardless of the considered propagation environment.

Abstract—Worldwide Interoperability for Microwave Access is an emerging wireless access networks offering high data rates and good range. These features, in addition to moderate installation and maintenance costs, make it an appealing last-mile delivery net-work for IPTV and ...

Mobile WiMAX standard defines air interface for mobile broadband wireless access (BWA) systems and aimed to provide high data rate with seamless mobility while maintaining the quality of service (QoS). However, QoS of real - time applications depends on the link quality, which necessitate the channel -aware
connection admission control (CAC) and scheduling schemes. In this paper Modulation aware CAC scheme and base station (BS) uplink scheduling algorithm are proposed to improve the system capacity and QoS performance respectively. The proposed CAC scheme aims to increase the admission of higher priority real time services by degrading the bandwidth of admitted lower priority connections on the basis of their channel status without deteriorating their QoS performance much. The performances of proposed algorithms are evaluated through simulation by considering the metrics like throughput, delay and number of connections admitted
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We investigate the provisioning of optical-frequency (wavelength) resources in optical networks that support broadband wireless access networks (BWANs). Millimeter-wave-over-fiber technology with operation in the 60-GHz license-free band is considered for the BWANs. The WDM-based optical network (handling BWAN traffic) is heterogenous, implying that it also bears traffic originating from (or destined for) wireline terminals. A discrete-event simulation is devised to ascertain the minimum number of wavelength channels required for various cases. Three WDM transmission schemes (pure, semihybrid, and hybrid) are described and used in the simulations. Hybrid WDM was observed to require the least number of wavelengths. However, the easily implementable pure-WDM scheme could be considered even if only a limited number of wavelength converters were deployed in the network.

WiMAX is a broadband wireless access technology facing the challenges of 3G and beyond communication systems. As frequency licensing is becoming commercially available throughout the world, it is still unclear whether WiMAX will be better positioned than its main competitors, such as UMTS. Therefore, it is critical to evaluate the technology within the foreseen all-IP communications. In the context of the WEIRD project, an architecture that includes the WiMAX technology in an all-IP communication system has been developed. The main capabilities of the WEIRD system include mechanisms to support adequate quality of service levels for a broad range of applications, from basic web traffic to multimedia and specialized applications, such as telemedicine and fire prevention. This paper presents a solution for macro mobility in an all-IP network with WiMAX as the access technology, based on the basic WEIRD architecture. The proposed approach has been implemented on a test-bed of the WEIRD system and evaluated in order to address the impact of the developed mechanisms upon the overall system performance. The results have shown that the mobility mechanisms introduce a rather small overhead, while having the capability to support a “make-before-break” handover process.

Digital systems are more flexible and environment-process-tolerant than analogue systems. They are more reliable and robust against cross-talk, interference and channel noises, and are capable of covering higher dynamic range than analogue systems. Wideband electronic analogue to digital conversion (ADC) systems have critical problems encountered in high-frequency broadband communication systems that the recent electronic ADCs (EADC) have experienced those such as uncertainty of sampling time. In this paper, an 80Gigasample/s all photonic sampling and quantization ADC and photonic digital to analogue conversion system with six effective number of bits (ENOB) is designed. By using this Photonic ADC (PADC), a digital radio over fibre link for wireless radio frequency (RF) signal transportation over 50 km single mode fibre has been designed whose performance is investigated in this paper.

International Journal of Wireless & Mobile Networks (IJWMN) is a bi monthly open access peer-reviewed journal that publishes articles which contribute new results in all areas of Wireless & Mobile Networks. The journal focuses on all technical and practical aspects of Wireless & Mobile Networks. The goal of this journal is to bring together researchers and practitioners from academia and industry to focus on advanced wireless & mobile networking concepts and establishing new collaborations in these areas.