Showing papers in "IEEE Communications Magazine in 2010"
TL;DR: This article surveys existing mobile phone sensing algorithms, applications, and systems, and discusses the emerging sensing paradigms, and formulates an architectural framework for discussing a number of the open issues and challenges emerging in the new area ofMobile phone sensing research.
Abstract: Mobile phones or smartphones are rapidly becoming the central computer and communication device in people's lives. Application delivery channels such as the Apple AppStore are transforming mobile phones into App Phones, capable of downloading a myriad of applications in an instant. Importantly, today's smartphones are programmable and come with a growing set of cheap powerful embedded sensors, such as an accelerometer, digital compass, gyroscope, GPS, microphone, and camera, which are enabling the emergence of personal, group, and communityscale sensing applications. We believe that sensor-equipped mobile phones will revolutionize many sectors of our economy, including business, healthcare, social networks, environmental monitoring, and transportation. In this article we survey existing mobile phone sensing algorithms, applications, and systems. We discuss the emerging sensing paradigms, and formulate an architectural framework for discussing a number of the open issues and challenges emerging in the new area of mobile phone sensing research.
2,316Â citations
TL;DR: A concept of a novel adaptation scheme in SLICE called distance-adaptive spectrum resource allocation, which can save more than 45 percent of required spectrum resources for a 12-node ring network, is presented.
Abstract: The rigid nature of current wavelength-routed optical networks brings limitations on network utilization efficiency. One limitation originates from mismatch of granularities between the client layer and the wavelength layer. The recently proposed spectrum-sliced elastic optical path network (SLICE) is expected to mitigate this problem by adaptively allocating spectral resources according to client traffic demands. This article discusses another limitation of the current optical networks associated with worst case design in terms of transmission performance. In order to address this problem, we present a concept of a novel adaptation scheme in SLICE called distance-adaptive spectrum resource allocation. In the presented scheme the minimum necessary spectral resource is adaptively allocated according to the end-to-end physical condition of an optical path. Modulation format and optical filter width are used as parameters to determine the necessary spectral resources to be allocated for an optical path. Evaluation of network utilization efficiency shows that distance-adaptive SLICE can save more than 45 percent of required spectrum resources for a 12-node ring network. Finally, we introduce the concept of a frequency slot to extend the current frequency grid standard, and discuss possible spectral resource designation schemes.
831Â citations
TL;DR: A concept of cell zooming is introduced, which adaptively adjusts the cell size according to traffic load, user requirements and channel conditions, which can greatly reduce the energy consumption, which leads to green cellular networks.
Abstract: Cell size in cellular networks is in general fixed based on the estimated traffic load. However, the traffic load can have significant spatial and temporal fluctuations, which bring both challenges and opportunities to the planning and operating of cellular networks. This article introduces a concept of cell zooming, which adaptively adjusts the cell size according to traffic load, user requirements and channel conditions. The implementation issues of cell zooming are then presented. Finally a usage case of cell zooming for energy saving is investigated. Centralized and distributed cell zooming algorithms are developed, and simulation results show that the proposed algorithms can greatly reduce the energy consumption, which leads to green cellular networks.
751Â citations
TL;DR: In this article, a holistic approach for energy efficient mobile radio networks is presented and the matter of having appropriate metrics and evaluation methods that allow assessing the energy efficiency of the entire system is discussed.
Abstract: Mobile communications are increasingly contributing to global energy consumption. In this article, a holistic approach for energy efficient mobile radio networks is presented. The matter of having appropriate metrics and evaluation methods that allow assessing the energy efficiency of the entire system is discussed. The mutual supplementary saving concepts comprise component, link and network levels. At the component level the power amplifier complemented by a transceiver and a digital platform supporting advanced power management are key to efficient radio implementations. Discontinuous transmission by base stations, where hardware components are switched off, facilitate energy efficient operation at the link level. At the network level, the potential for reducing energy consumption is in the layout of networks and their management, that take into account slowly changing daily load patterns, as well as highly dynamic traffic fluctuations. Moreover, research has to analyze new disruptive architectural approaches, including multi-hop transmission, ad-hoc meshed networks, terminal-to-terminal communications, and cooperative multipoint architectures.
621Â citations
TL;DR: It is pointed out that a popular assumption - that multipath channels are sparse in their equivalent baseband representation - has pitfalls and there are over-complete dictionaries that lead to much sparser channel representations and better estimation performance.
Abstract: Compressive sensing is a topic that has recently gained much attention in the applied mathematics and signal processing communities. It has been applied in various areas, such as imaging, radar, speech recognition, and data acquisition. In communications, compressive sensing is largely accepted for sparse channel estimation and its variants. In this article we highlight the fundamental concepts of compressive sensing and give an overview of its application to pilot aided channel estimation. We point out that a popular assumption - that multipath channels are sparse in their equivalent baseband representation - has pitfalls. There are over-complete dictionaries that lead to much sparser channel representations and better estimation performance. As a concrete example, we detail the application of compressive sensing to multicarrier underwater acoustic communications, where the channel features sparse arrivals, each characterized by its distinct delay and Doppler scale factor. To work with practical systems, several modifications need to be made to the compressive sensing framework as the channel estimation error varies with how detailed the channel is modeled, and how data and pilot symbols are mixed in the signal design.
553Â citations
TL;DR: The main current and emerging solutions that are suitable for WHANs, including ZigBee, Z-Wave, INSTEON, Wavenis, and IP-based technology are surveyed.
Abstract: Wireless home automation networks comprise wireless embedded sensors and actuators that enable monitoring and control applications for home user comfort and efficient home management. This article surveys the main current and emerging solutions that are suitable for WHANs, including ZigBee, Z-Wave, INSTEON, Wavenis, and IP-based technology.
531Â citations
TL;DR: A survey of the MIMO techniques in the two standards, IEEE 802.16e/m and 3GPP LTE/LTE-Advanced, which compares the features of the two and depicts the engineering considerations.
Abstract: IEEE 802.16m and 3GPP LTE-Advanced are the two evolving standards targeting 4G wireless systems. In both standards, multiple-input multiple-output antenna technologies play an essential role in meeting the 4G requirements. The application of MIMO technologies is one of the most crucial distinctions between 3G and 4G. It not only enhances the conventional point-to-point link, but also enables new types of links such as downlink multiuser MIMO. A large family of MIMO techniques has been developed for various links and with various amounts of available channel state information in both IEEE 802.16e/m and 3GPP LTE/LTE-Advanced. In this article we provide a survey of the MIMO techniques in the two standards. The MIMO features of the two are compared, and the engineering considerations are depicted.
511Â citations
TL;DR: The architectures and various ROADM implementations including colorless, directionless, and contentionless add/drop structures are presented and the effect of scaling bit rates beyond 100 Gb/s onROADM architectures is reviewed including providing variable channel bandwidth depending on bit rate.
Abstract: Flexibility to support mesh topologies, dynamic capacity allocation, and automated network control and light path setup are key elements in the design of next-generation optical transport networks. To realize these capabilities, reconfigurable optical add/drop multiplexers with dynamic add/drop structures, embedded control planes, and lightpath characterization are required. This article presents the architectures and various ROADM implementations including colorless, directionless, and contentionless add/drop structures. The effect of scaling bit rates beyond 100 Gb/s on ROADM architectures is reviewed including providing variable channel bandwidth depending on bit rate. Automated provisioning and restoration using the GMPLS control plane and optical measurement approaches for lightpaths are also discussed.
484Â citations
TL;DR: The objective of this article is to illustrate the power of spatial models and analytical techniques in the design of wireless networks, and to provide an entry-level tutorial.
Abstract: The performance of wireless networks depends critically on their spatial configuration, because received signal power and interference depend critically on the distances between numerous transmitters and receivers. This is particularly true in emerging network paradigms that may include femtocells, hotspots, relays, white space harvesters, and meshing approaches, which are often overlaid with traditional cellular networks. These heterogeneous approaches to providing high-capacity network access are characterized by randomly located nodes, irregularly deployed infrastructure, and uncertain spatial configurations due to factors like mobility and unplanned user-installed access points. This major shift is just beginning, and it requires new design approaches that are robust to spatial randomness, just as wireless links have long been designed to be robust to fading. The objective of this article is to illustrate the power of spatial models and analytical techniques in the design of wireless networks, and to provide an entry-level tutorial.
446Â citations
TL;DR: In this paper, a brief review of continuous and non-continuous CA techniques is given, followed by two data aggregation schemes in physical and medium access control layers, and possible technical solutions for the asymmetric CA problem, control signaling design, handover control and guard band setting are reviewed.
Abstract: In order to achieve up to 1 Gb/s peak data rate in future IMT-Advanced mobile systems, carrier aggregation technology is introduced by the 3GPP to support very-high-data-rate transmissions over wide frequency bandwidths (e.g., up to 100 MHz) in its new LTE-Advanced standards. This article first gives a brief review of continuous and non-continuous CA techniques, followed by two data aggregation schemes in physical and medium access control layers. Some technical challenges for implementing CA technique in LTE-Advanced systems, with the requirements of backward compatibility to LTE systems, are highlighted and discussed. Possible technical solutions for the asymmetric CA problem, control signaling design, handover control, and guard band setting are reviewed. Simulation results show Doppler frequency shift has only limited impact on data transmission performance over wide frequency bands in a high-speed mobile environment when the component carriers are time synchronized. The frequency aliasing will generate much more interference between adjacent component carriers and therefore greatly degrades the bit error rate performance of downlink data transmissions.
446Â citations
TL;DR: The emerging 802.11 standard is overviewed and its finalized amendments and those under development are highlighted, to address the technical context of its extensions.
Abstract: The introduction of IEEE's 80211 standards has enabled a mass market, with a huge impact in the home, office, and public areas Today, laptops, PCs, printers, cellular phones, VoIP phones, MP3 players, Blu-Ray players, and many more devices incorporate wireless LAN technology With low-cost chipsets and support for high data rates, 80211 has become a universal solution for an ever increasing application space As a direct consequence of its high market penetration, several amendments to the basic 80211 standard have been developed or are under development They fix technology issues or add functionality expected to be required by future applications In this article we overview the emerging 80211 standard and address the technical context of its extensions The article highlights its finalized amendments and those under development
TL;DR: The role of forward error correction has become of critical importance in fiber optic communications, as backbone networks increase in speed to 40 and 100 Gb/s, particularly as poor optical-signal-to-noise environments are encountered.
Abstract: The role of forward error correction has become of critical importance in fiber optic communications, as backbone networks increase in speed to 40 and 100 Gb/s, particularly as poor optical-signal-to-noise environments are encountered. Such environments become more commonplace in higher-speed environments, as more optical amplifiers are deployed in networks. Many generations of FEC have been implemented, including block codes and concatenated codes. Developers now have options to consider hard-decision and soft-decision codes. This article describes the advantages of each type in particular transmission environments.
TL;DR: The existing access methods for femtocells together with their benefits and drawbacks are explained and the need for hybrid access methods and several models are presented.
Abstract: Femtocells are a solution that helps to reduce the capital and operational expenditure of a mobile network while enhancing system coverage and capacity. However, the avoidance of interference is still an issue that needs to be addressed to successfully deploy a femtocell tier over existing macrocell networks. Moreover, interference is strongly dependent on the type of access control, which decides if a given user can or cannot connect to the femtocell. In this article the existing access methods for femtocells together with their benefits and drawbacks are explained. A description of the business model and technical impact of access methods in femto/macro networks is also provided. Finally, the need for hybrid access methods and several models are presented.
TL;DR: Support for carrier aggregation requires enhancement to the LTE Release 8/9 PHY, MAC, and RRC layers while ensuring that LTE Release 10 maintains backward compatibility to LTE Release8/9.
Abstract: Carrier aggregation is one of the most distinct features of 4G systems including LTEAdvanced, which is being standardized in 3GPP as part of LTE Release 10. This feature allows scalable expansion of effective bandwidth delivered to a user terminal through concurrent utilization of radio resources across multiple carriers. These carriers may be of different bandwidths, and may be in the same or different bands to provide maximum flexibility in utilizing the scarce radio spectrum available to operators. Support for this feature requires enhancement to the LTE Release 8/9 PHY, MAC, and RRC layers while ensuring that LTE Release 10 maintains backward compatibility to LTE Release 8/9. This article provides an overview of carrier aggregation use cases and the framework, and their impact on LTE Release 8/9 protocol layers.
TL;DR: The development of the EEE standard and how energy savings resulting from the adoption of EEE may exceed $400 million per year in the U.S. alone are described and results show that packet coalescing can significantly improve energy efficiency while keeping absolute packet delays to tolerable bounds are presented.
Abstract: Ethernet is the dominant wireline communications technology for LANs with over 1 billion interfaces installed in the U.S. and over 3 billion worldwide. In 2006 the IEEE 802.3 Working Group started an effort to improve the energy efficiency of Ethernet. This effort became IEEE P802.3az Energy Efficient Ethernet (EEE) resulting in IEEE Std 802.3az-2010, which was approved September 30, 2010. EEE uses a Low Power Idle mode to reduce the energy consumption of a link when no packets are being sent. In this article, we describe the development of the EEE standard and how energy savings resulting from the adoption of EEE may exceed $400 million per year in the U.S. alone (and over $1 billion worldwide). We also present results from a simulation-based performance evaluation showing how packet coalescing can be used to improve the energy efficiency of EEE. Our results show that packet coalescing can significantly improve energy efficiency while keeping absolute packet delays to tolerable bounds. We are aware that coalescing may cause packet loss in downstream buffers, especially when using TCP/IP. We explore the effects of coalescing on TCP/IP flows with an ns-2 simulation, note that coalescing is already used to reduce packet processing load on the system CPU, and suggest open questions for future work. This article will help clarify what can be expected when EEE is deployed.
TL;DR: A case study is presented that uses electromagnetic technology in a small-scale underwater wireless sensor network and the results demonstrate the likely effectiveness of the designated network.
Abstract: Most underwater wireless networks use acoustic waves as the transmission medium nowadays, but the chances of getting much more out of acoustic modems are quite remote. Optical links are impractical for many underwater applications. Given modern operational requirements and digital communications technology, the time is now ripe for re-evaluating the role of electromagnetic signals in underwater environments. The research presented in this article is motivated by the limitations of current and established wireless underwater techniques, as well as the potential that electromagnetic waves can offer to underwater applications. A case study is presented that uses electromagnetic technology in a small-scale underwater wireless sensor network. The results demonstrate the likely effectiveness of the designated network.
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TL;DR: In this article, the authors discuss interface technology options for Ethernet and OTN beyond 100G in light of the current 100G standards, taking into account likely evolution paths of interface technologies over the next 10 years.
Abstract: With 100G technologies standardized, in the context of both Ethernet and the optical transport network (OTN), 100G router ports and 100G optical transport interfaces are commercially available. At the same time, heavily data-centric users are starting to ask for higher-rate interfaces. First speculations include 400G as well as 1T as the next possible Ethernet standards. In this article we discuss interface technology options for Ethernet and OTN beyond 100G in light of the current 100G standards, taking into account likely evolution paths of interface technologies over the next 10 years.
TL;DR: This article discusses the evolution from opportunistic networking to opportunistic computing; a survey of key recent achievements in opportunism networking is surveyed; and the main concepts and challenges of opportunistic Computing are described.
Abstract: Personal computing devices, such as smart-phones and PDAs, are commonplace, bundle several wireless network interfaces, can support compute intensive tasks, and are equipped with powerful means to produce multimedia content. Thus, they provide the resources for what we envision as a human pervasive network: a network formed by user devices, suitable to convey to users rich multimedia content and services according to their interests and needs. Similar to opportunistic networks, where the communication is built on connectivity opportunities, we envisage a network above these resources that joins together features of traditional pervasive networks and opportunistic networks fostering a new computing paradigm: opportunistic computing. In this article we discuss the evolution from opportunistic networking to opportunistic computing; we survey key recent achievements in opportunistic networking, and describe the main concepts and challenges of opportunistic computing. We finally envision further possible scenarios and functionalities to make opportunistic computing a key player in the next-generation Internet.
TL;DR: The capabilities of available wireless communication technologies are explored in order to produce a win-win situation while selecting suitable carrier for a single application or a profile of similar applications.
Abstract: Intelligent transport systems are the rising technology in the near future to build cooperative vehicular networks in which a variety of different ITS applications are expected to communicate with a variety of different units. Therefore, the demand for highly customized communication channel for each or sets of similar ITS applications is increased. This article explores the capabilities of available wireless communication technologies in order to produce a win-win situation while selecting suitable carrier( s) for a single application or a profile of similar applications. Communication requirements for future ITS applications are described to select the best available communication interface for the target application(s).
TL;DR: Insight is provided to both relay standards that could be helpful for readers to fully comprehend practical ways of incorporating relays into 4 G wireless broadband networks.
Abstract: There are two candidates for IMT-Advanced (4 G) standards, LTE-Advanced by 3 GPP and 802.16 m by IEEE. This article focuses on relay architectures in 16 m and LTE-A, and discusses design principles and trade-offs leading to decisions in each standards group. Basically, 16 m relay and LTE-A Release 10 relay are very similar technologies where the relay is essentially an orthogonal frequency-division multiple access base station with a wireless backhaul link. However, some open issues, such as mobility, power saving, multihop architecture, transparent relaying, multi-arrier transmission, and cooperative transmission, are still left as challenges for engineers and researchers. This article provides insights to both relay standards that could be helpful for readers to fully comprehend practical ways of incorporating relays into 4 G wireless broadband networks.
TL;DR: DistressNet is presented, an ad hoc wireless architecture that supports disaster response with distributed collaborative sensing, topology-aware routing using a multichannel protocol, and accurate resource localization andimation techniques improve localization accuracy in difficult environments.
Abstract: Situational awareness in a disaster is critical to effective response. Disaster responders require timely delivery of high volumes of accurate data to make correct decisions. To meet these needs, we present DistressNet, an ad hoc wireless architecture that supports disaster response with distributed collaborative sensing, topology-aware routing using a multichannel protocol, and accurate resource localization. Sensing suites use collaborative and distributed mechanisms to optimize data collection and minimize total energy use. Message delivery is aided by novel topology management, while congestion is minimized through the use of mediated multichannel radio protocols. Estimation techniques improve localization accuracy in difficult environments.
TL;DR: It is shown that although the existing standardized point-to-point MIMO channel models can be applied to a certain extent to model cooperative M IMO channels, many new challenges remain in cooperative MIMo channel modeling, such as how to model mobile-to -mobile channels, and how to characterize the heterogeneity and correlation of multiple links at the system level appropriately.
Abstract: Cooperative multiple-input multiple-output technology allows a wireless network to coordinate among distributed antennas and achieve considerable performance gains similar to those provided by conventional MIMO systems. It promises significant improvements in spectral efficiency and network coverage and is a major candidate technology in various standard proposals for the fourth-generation wireless communication systems. For the design and accurate performance assessment of cooperative MIMO systems, realistic cooperative MIMO channel models are indispensable. This article provides an overview of the state of the art in cooperative MIMO channel modeling. We show that although the existing standardized point-to-point MIMO channel models can be applied to a certain extent to model cooperative MIMO channels, many new challenges remain in cooperative MIMO channel modeling, such as how to model mobile-to-mobile channels, and how to characterize the heterogeneity and correlation of multiple links at the system level appropriately.
TL;DR: The market and technological perspectives for SONs are introduced and a self-booting mechanism for a newly added evolved NodeB without a dedicated backhaul interface is illustrated, and mobility load balancing as one of the most important selfoptimization issues for Long Term Evolution networks is discussed.
Abstract: With the rapid growth of mobile communications, deployment and maintenance of cellular mobile networks are becoming more and more complex, time consuming, and expensive. In order to meet the requirements of network operators and service providers, the telecommunication industry and international standardization bodies have recently paid intensive attention to the research and development of self-organizing networks. In this article we first introduce both the market and technological perspectives for SONs. Then we focus on the self-configuration procedure and illustrate a self-booting mechanism for a newly added evolved NodeB without a dedicated backhaul interface. Finally, mobility load balancing as one of the most important selfoptimization issues for Long Term Evolution networks is discussed, and a distributed MLB algorithm with low handover cost is proposed and evaluated.
TL;DR: The IEEE 802.15.4a standard is presented, the first international standard that specifies a wireless physical layer to enable precision ranging, and introduces new options for the physical layer in order to support higher data rates, extended range, improved robustness against interference, and mobility, while enabling new applications based on distance information of the devices in a low-rate wireless personal area network.
Abstract: This article presents the IEEE 802.15.4a standard, the first international standard that specifies a wireless physical layer to enable precision ranging. As an amendment to the popular IEEE 802.15.4-2006, the IEEE 802.15.4a-2007 standard introduces new options for the physical layer in order to support higher data rates, extended range, improved robustness against interference, and mobility, while enabling new applications based on distance information of the devices in a low-rate wireless personal area network.
TL;DR: The growing trend of warehouse-scale mega- datacenter computing, the Internet transformation driven by mega-datacenter applications, and the opportunities and challenges for fiber optic communication technologies to support the growth of mega- Datacentre computing in the next three to four years are reviewed.
Abstract: In this article we review the growing trend of warehouse-scale mega-datacenter computing, the Internet transformation driven by mega-datacenter applications, and the opportunities and challenges for fiber optic communication technologies to support the growth of mega-datacenter computing in the next three to four years.
TL;DR: The concept of ITSp is introduced and possible communication technology candidates for ITSp are analyzed to help improve the vehicles, traffic, and transportation safety, efficiency and sustainability.
Abstract: Recent years have witnessed numerous technical breakthroughs in electronics, computing, sensing, robotics, control, signal processing, and communications. These have significantly advanced the state of applications of intelligent transportation systems. More recently, as one leading effort toward the cyber-physical-social system, the concept of intelligent transportation spaces was proposed to further improve the vehicles, traffic, and transportation safety, efficiency and sustainability. ITSp integrate not only various ITS modules, but also pedestrians, vehicles, roadside infrastructures, traffic management centers, sensors, and satellites. With distributed and pervasive intelligence, ITSp clearly impose some stringent requirements on the information exchange among all entities within the ITSp, in terms of the information availability, reliability, fidelity, and timeliness. These requirements, together with the high mobility of vehicles and the highly variable network topology, make the communications and networking for ITSp very challenging. This article will introduce the concept of ITSp and analyze possible communication technology candidates for ITSp. Further discussions will also be provided at the end of this article.
TL;DR: This article compares interference management solutions across the two main 4G standards: IEEE 802.16m (WiMAX) and 3GPP-LTE and addresses radio resource management schemes for interference mitigation, which include power control and adaptive fractional frequency reuse.
Abstract: 4G cellular standards are targeting aggressive spectrum reuse (frequency reuse 1) to achieve high system capacity and simplify radio network planning. The increase in system capacity comes at the expense of SINR degradation due to increased intercell interference, which severely impacts cell-edge user capacity and overall system throughput. Advanced interference management schemes are critical for achieving the required cell edge spectral efficiency targets and to provide ubiquity of user experience throughout the network. In this article we compare interference management solutions across the two main 4G standards: IEEE 802.16m (WiMAX) and 3GPP-LTE. Specifically, we address radio resource management schemes for interference mitigation, which include power control and adaptive fractional frequency reuse. Additional topics, such as interference management for multitier cellular deployments, heterogeneous architectures, and smart antenna schemes will be addressed in follow-up papers.
TL;DR: This tutorial highlights some of the potentials of WLEDs, which have the potential to revolutionize how the authors use light, including not only for illumination, but also for communications, sensing, navigation, imaging, and many more applications.
Abstract: As we step further into the 21st century, the demand for sustainable energy-efficient technology grows higher. The important area of electric lighting, currently dominated by decades-old incandescent and fluorescent sources, is being taken over by white light emitting diodes, which are solid state devices with much greater energy savings. Replacement of current inefficient lighting by these LEDs will result in reduction of global carbon dioxide emissions, a major cause of global warming, among other things. WLEDs hold the potential, in the field of photonics, to be as transformational as the transistor was in electronics. This core device has the potential to revolutionize how we use light, including not only for illumination, but also for communications, sensing, navigation, imaging, and many more applications. In this tutorial we highlight some of the potentials.
TL;DR: An overview of opportunities and challenges related to joint deployments of macro and femtocells is provided and an analysis framework for quantifying macro offloading benefits in realistic network deployment scenarios by means of advanced performance analysis techniques is created.
Abstract: This article provides an overview of opportunities and challenges related to joint deployments of macro and femtocells. It provides insights on possible deployment architectures for femtocells along with an analysis framework for quantifying macro offloading benefits in realistic network deployment scenarios by means of advanced performance analysis techniques. Such benefits include potential enhancement in quality of radio signals for users served by the macro network in joint macro-femto deployments. This in turn translates into potentially better data rates (throughput) for macrocell users and may offer the possibility of adding more users to the macro network while preserving the network configuration -- resulting in direct capital expenditure savings. The approach taken in this article consists of creating a framework for quantifying macro offloading benefits in joint macro-femto deployments. A baseline configuration where all users (indoor and outdoor) are served by a traditional macro network (state-of-the-art macro only network) is considered first. The analysis is followed through joint macro-femto deployments, where femtocells serve indoor users. Through comparison of the baseline configuration and the joint macro-femto analysis, we quantify the benefits of the joint macro-femto deployment.
TL;DR: This article highlights QoS frameworks and features of OFDMA-based 4G technologies - IEEE802.16e, IEEE 802.16m, and LTE - to support various applications' QoS requirements to be future-proof to deliver the incumbent as well as emerging mobile Internet applications.
Abstract: A quality of service framework is a fundamental component of a 4G broadband wireless network for satisfactory service delivery of evolving Internet applications to end users, and managing the network resources. Today's popular mobile Internet applications, such as voice, gaming, streaming, and social networking services, have diverse traffic characteristics and, consequently, different QoS requirements. A rather flexible QoS framework is highly desirable to be future-proof to deliver the incumbent as well as emerging mobile Internet applications. This article highlights QoS frameworks and features of OFDMA-based 4G technologies - IEEE 802.16e, IEEE 802.16m, and LTE - to support various applications' QoS requirements. A few advanced QoS features such as new scheduling service (i.e., aGP), quick access, delayed bandwidth request, and priority controlled access in IEEE 802.16m are explained in detail. A brief comparison of the QoS framework of the aforementioned technologies is also provided.