Performance analysis of a generalized and autonomous DRX scheme

A generalized and autonomous DRX (discontinuous reception) scheme, applicable to both 3GPP and IEEE 802.16e standards, is analyzed by two - level Markov chain modeling along with the ETSI packet traffic model. Numerical analysis showed that this scheme is capable of autonomously adjusting DRX cycle to keep up with changing UE activity level with no signaling overhead increase, thus produces a better tuned DRX operation. Quantitative comparison with the power saving schemes of 3GPP and 802.16e standards demonstrated that it is advantageous over and generalization of these power saving schemes

Characterization and Optimization of Resource Utilization for Cellular Networks.

Cellular data networks have experienced significant growth in the recent years particularly due to the emergence of smartphones. Despite its popularity, there remain two major challenges associated with cellular carriers and their customers: carriers operate under severe resource constraints, while many mobile applications are unaware of the cellular specific characteristics, leading to inefficient radio resource and handset energy utilization. My dissertation is dedicated to address both challenges, aiming at providing practical, effective, and efficient methods to monitor and to reduce the resource utilization and bandwidth consumption in cellular networks. Specifically, from carriers' perspective, we performed the first measurement study to understand the state-of-the-art of resource utilization for a commercial cellular network, and revealed that fundamental limitation of the current resource management policy is treating all traffic according to the same resource management policy globally configured for all users. On mobile applications' side, we developed a novel data analysis framework called ARO (mobile Application Resource Optimizer), the first tool that exposes the interaction between mobile applications and the radio resource management policy, to reveal inefficient resource usage due to a lack of transparency in the lower-layer protocol behavior. ARO revealed that many popular applications built by professional developers have significant resource utilization inefficiencies that are previously unknown. Motivated by the observations from both sides, we further proposed a novel resource management framework that enables the cooperation between handsets and the network to allow adaptive resource release, therefore better balancing the key tradeoffs in cellular networks. We also investigated the problem of reducing the bandwidth consumption in cellular networks by performing the first network-wide study of HTTP caching on smartphones due to its popularity. Our findings suggest that for web caching, there exists a huge gap between the protocol specification and the protocol implementation on today's mobile devices, leading to significant amount of redundant network traffic.PHDComputer Science and EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/94024/1/fengqian_1.pd

3G migration in Pakistan

The telecommunication industry in Pakistan has come a long way since the country\u27s independence in 1947. The initial era could be fairly termed as the PTCL (Pakistan Telecommunication Company Limited) monopoly, for it was the sole provider of all telecommunication services across the country. It was not until four decades later that the region embarked into the new world of wireless communication, hence ending the decades old PTCL monopoly. By the end of the late 1990\u27s, government support and international investment in the region opened new doors to innovation and better quality, low cost, healthy competition. Wireless licenses for the private sector in the telecommunication industry triggered a promising chain of events that resulted in a drastic change in the telecommunication infrastructure and service profile. The newly introduced wireless (GSM) technology received enormous support from all stakeholders (consumers, regulatory body, and market) and caused a vital boost in Pakistan\u27s economy. Numerous tangential elements had triggered this vital move in the history of telecommunications in Pakistan. Entrepreneurs intended to test the idea of global joint ventures in the East and hence the idea of international business became a reality. The technology had proven to be a great success in the West, while Pakistan\u27s telecom consumer had lived under the shadow of PTCL dominance for decades and needed more flexibility. At last the world was moving from wired to wireless! Analysts termed this move as the beginning of a new era. The investors, telecommunication businesses, and Pakistani treasury prospered. It was a win-win situation for all involved. The learning curve was steep for both operators and consumers but certainly improved over time. In essence, the principle of deploying the right technology in the right market at the right time led to this remarkable success. The industry today stands on the brink of a similar crossroads via transition from second generation to something beyond. With the partial success of 3G in Europe and the USA, the government has announced the release of three 3G licenses by mid 2009. This decision is not yet fully supported by all but still initiated parallel efforts by the operators and the vendors to integrate this next move into their existing infrastructure

Quantifying Potential Energy Efficiency Gain in Green Cellular Wireless Networks

Conventional cellular wireless networks were designed with the purpose of providing high throughput for the user and high capacity for the service provider, without any provisions of energy efficiency. As a result, these networks have an enormous Carbon footprint. In this paper, we describe the sources of the inefficiencies in such networks. First we present results of the studies on how much Carbon footprint such networks generate. We also discuss how much more mobile traffic is expected to increase so that this Carbon footprint will even increase tremendously more. We then discuss specific sources of inefficiency and potential sources of improvement at the physical layer as well as at higher layers of the communication protocol hierarchy. In particular, considering that most of the energy inefficiency in cellular wireless networks is at the base stations, we discuss multi-tier networks and point to the potential of exploiting mobility patterns in order to use base station energy judiciously. We then investigate potential methods to reduce this inefficiency and quantify their individual contributions. By a consideration of the combination of all potential gains, we conclude that an improvement in energy consumption in cellular wireless networks by two orders of magnitude, or even more, is possible.Comment: arXiv admin note: text overlap with arXiv:1210.843

Green Cellular Networks: A Survey, Some Research Issues and Challenges

Energy efficiency in cellular networks is a growing concern for cellular operators to not only maintain profitability, but also to reduce the overall environment effects. This emerging trend of achieving energy efficiency in cellular networks is motivating the standardization authorities and network operators to continuously explore future technologies in order to bring improvements in the entire network infrastructure. In this article, we present a brief survey of methods to improve the power efficiency of cellular networks, explore some research issues and challenges and suggest some techniques to enable an energy efficient or "green" cellular network. Since base stations consume a maximum portion of the total energy used in a cellular system, we will first provide a comprehensive survey on techniques to obtain energy savings in base stations. Next, we discuss how heterogeneous network deployment based on micro, pico and femto-cells can be used to achieve this goal. Since cognitive radio and cooperative relaying are undisputed future technologies in this regard, we propose a research vision to make these technologies more energy efficient. Lastly, we explore some broader perspectives in realizing a "green" cellular network technologyComment: 16 pages, 5 figures, 2 table

Energy-efficient LTE transmission techniques : introducing Green Radio from resource allocation perspective

Energy consumption has recently become a key issue from both environmental and economic considerations. A typical mobile phone network in the UK may consume approximately 40- 50 MW, contributing a significant proportion of the total energy consumed by the information technology industry. With the worldwide growth in the number of mobile subscribers, the associated carbon emissions and growing energy costs are becoming a significant operational expense, leading to the need for energy reduction. The Mobile VCE Green Radio Project has been launched, which targets to achieve 100x energy reduction of the current wireless networks by 2020. In this thesis, energy-efficient resource allocation strategies have been investigated taking the LTE system as an example. Firstly, theoretical analysis of energy-efficient design in cellular environments is provided according to the Shannon Theory. Based on a two-link scenario the performance of simultaneous transmission and orthogonal transmission for network power minimization under the specified rate constraints is investigated. It is found that simultaneous transmission consumes less power than orthogonal transmission close to the base station, but much more power in the cell-edge area. Also, simulation results suggest that the energy-efficient switching margins between these two schemes are dominated by the sum total of their required data rates. New definitions of power-utility and fairness metrics are further proposed, following by the design of weighted resource allocation approaches based on efficiency-fairness trade-offs. Apart from energy-efficient multiple access between different links, the energy used by individual base stations can also be reduced. For example, deploying sleep modes is an effective approach to reduce radio base station operational energy consumption. By periodically switching off the base station transmission, or using fewer transmit antennas, the energy consumption of base station hardware may decrease. By delivering less control signalling overhead, the radio frequency energy consumption can also be reduced. Simulation results suggest that up to 90% energy reduction can be obtained in low traffic conditions by employing time-domain optimization in each radio frame. The optimum on/off duty cycle is derived, enabling the energy consumption of the base station to scale with traffic loads. In the spatial-domain, an antenna selection criterion is proposed, indicating the most energy-efficient antenna configuration with the knowledge of users’ locations and quality of service requirements. Without time-domain sleep modes, using fewer transmit antennas could outperform full antenna transmission. However, with time-domain sleep modes, using all available antennas is generally the most energy-efficient choice

Performance and Power Characterization of Cellular Networks and Mobile Application Optimizations.

Smartphones with cellular data access have become increasingly popular with the wide variety of mobile applications. However, the performance and power footprint of these mobile applications are not well-understood, and due to the unawareness of the cellular specific characteristics, many of these applications are causing inefficient radio resource and device energy usage. In this dissertation, we aim at providing a suite of systematic methodology and tools to better understand the performance and power characteristics of cellular networks (3G and the new LTE 4G networks) and the mobile applications relying upon, and to optimize the mobile application design based on this understanding. We have built the MobiPerf tool to understand the characteristics of cellular networks. With this knowledge, we make detailed analysis on smartphone application performance via controlled experiments and via a large-scale data set from one major U.S. cellular carrier. To understand the power footprint of mobile applications, we have derived comprehensive power models for different network types and characterize radio energy usage of various smartphone applications via both controlled experiments and 7-month-long traces collected from 20 real users. Specifically, we characterize the radio and energy impact of the network traffic generated when the phone screen is off and propose the screen-aware traffic optimization. In addition to shedding light to the mobile application design throughout our characterization analysis, we further design and implement a real optimization system RadioProphet, which uses historical traffic features to make predictions and intelligently deallocate radio resource for improved radio and energy efficiency.PhDComputer Science & EngineeringUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/99905/1/hjx_1.pd

Technologies of Mobile Communication

Long-Term Evolution (LTE) is a new technology recently specified by 3GPP-Third Generation Partnership Project on the way towards fourth-generation mobile. This thesis presents the main technical features of this technology as well as its performances in terms of peak bit rate and average cell throughput, among others. LTE entails a big technological improvement as compared with the previous 3G standards. 1 However, this thesis also demonstrates that LTE performances do not fulfill the technical requirements established by ITU-R to classify one radio access technology as a member of the IMT-Advanced family of standards. Thus, this thesis describes the procedure followed by 3GPP to address these challenging requirements. Through the design and optimization of new radio access techniques and a further evolution of the system, 3GPP is laying down the foundations of the future LTE-Advanced standard, the 3GPP candidate for 4G