Search

The basin of Gran valley is considered as one of dry valleys in Aljazeera district that belongs to Hit municipality 180 km west Baghdad. Area unit was conformed from some measured quantitative properties. Geomorphological and morphometric properties was used to construct data base relied on topographical maps, satellite image and DEM. Basin topography was studied. These landforms were parted into topological, erosional, sedimentary and carstic origins forms. Furthermore, morphometric properties represented the relationships among factors, corrosion processes and terrestrial phenomena such as area, forms, topography and aquatic drain net. Moreover, longitudinal, cross- sections and natural factors were associated. Results revealed that area of basin was 91.41 km2 which its water flew in Euphrates. The basin was very meandering semi-oval shape. Its river levels were 4 with 121 courses that possessed overall length of 149.7 km.

This research article has been conducted for the efficient use of frequency spectrum in multi-RAT cellular network using dynamic spectrum refarming (DSR). For this purpose, two overlapping networks, GERAN and EUTRAN, and their voice and data traffic statistics are taken into consideration. Our investigation of hourly traffic changes in the voice service in the GERAN and the data service in the EUTRAN (which are the dominant services of each of these networks), indicates that these changes are approximately orthogonal. This issue is the main motivation for use of DSR methods, including DSR without inband/guardband (I/G) overlay and DSR with I/G overlay, for efficient assignment of frequency resources to GERAN and EUTRAN. In this paper, the main focus is on the process of performing DSR with I/G overlay in a real network and its challenges. For this purpose, we used a nonlinear autoregressive neural network to predict the traffic changes of voice service in the GERAN. By this method, the prediction error is less than 6.5% in the peak hours. Also, a method for efficient use of GERAN and EUTRAN carrier numbers (ARFCN and EARFCN, respectively) has been proposed to reduce the mutual interference in DSR with I/G overlay. The results show the significant impact of the DSR with I/G overlay on increasing the EUTRAN average bit rate compared to the classic spectrum refarming method (168% in downlink and 146% in uplink).

Проблематика. Сьогодні мобільний зв'язок зайнятий наданням IP-сервісів та передаванням мультимедійного контенту з одного місця в інше, але вже завтра нове покоління 5G зможе контролювати широкий спектр матеріальних об'єктів у реальному часі із лише незначним втручанням людини. Створюється так званий Інтернет речей «IoT» із безліччю нових привабливих програм. У поданій роботі розглянутий новий підхід до розподілу ресурсів для майбутніх безпроводових локальних мереж у складі мереж 5G. Мета досліджень. DIDO (Distributed Input Distributed Output) – нова технологія, яка направлена на надання послуг гнучкої багатокористувацької безпроводової мережі в усьому світі у межах міжнародного узгодження і конвенцій для використовуваних частот серед інших мобільних технологій для інтеграції з 5G. Техніка DIDO націлена на розподіл ресурсів для майбутніх мереж безпроводового зв'язку, які можуть використовувати широкий спектр «нетрадиційних» частот від 3 МГц до 30 ГГц і працювати незалежно одна від одної із повною пропускною спроможністю і високою швидкістю передачі даних на відстанях від 100 м до 1000 км. Методика реалізації. Був проведений аналіз усіх відомих публикацій, які присвячені новому поколінню мобільного зв'язку 5G. Досліджувались аспекти взаємодії 5G із WLAN, BT, WSN та іншими мікро- и пікорадіомережами. Розглянутий новий підхід до розподілу частотних ресурсів для майбутньої WLAN. Результати досліджень. Представлений огляд, а також обговорюються основні напрямки розробки майбутніх мереж мобільного радіозв'язку 5G за стандартом IMT 2020. Вони включають, окрім іншого, перспективну технологію DIDO (Distributed Input Distributed Output) для розподілу ресурсів для майбутніх мереж безпроводового зв'язку. Зазначена технологія повинна тільки розширити існуючу інфраструктуру мобільного радіозв'язку GERAN, UTRAN, SAE і IMS попередніх поколінь 2G – 4G за допомогою гнучкої «всесвітньої» WLAN, яка працює з використанням баз даних для доступних діапазонів частот та з доступом до Web-контенту на основі так званих DIDO-центрів (DIDO Data Centers). Висновки. Эфективні WLAN, у тому числі із використанням техноології DIDO, повинні стати частиною нових систем покоління 5G. У якості нового метода розподілу ресурсів для майбутніх безпроводових локальних мереж, з точки зору деяких провідних компаній, таких як Rearden, Microsoft, Samsung, Huawei, має бути використаний метод DIDO. Background. Nowadays wireless and mobile communication is occupied with provision in general of IP-services and transmission of MM-content from one place to another, but tomorrow the new 5G will be able to control a wide range of objects in real time with only insignificant human intervention. IoT with multiple new attractive apps is created. An important new approach for resource allocation for future WLAN towards 5G has to be discussed within the work. Objective. DIDO (Distributed Input Distributed Output) – a new technology aimed to provide flexible multiuser wireless LAN everywhere under international voting and conventions for the used frequencies amongst other mobile technologies towards 5G. DIDO is aimed to resource allocation for future wireless communication networks which can use the wide non-traditional frequencies spectra between 3MHz and 30GHz and independently with full bandwidth and higher data rate operate under the distances between 100 m and 1000 km. Methods. Analysis of all known publications devoted to the new generation of mobile communication 5G was done. The interoperability aspects of 5G to WLAN, BT, WSN and other micro- and pico- radio nets were discussed. A new approach to frequency resource allocation for future WLAN was examined. Results. An overview is given as well as main research points of view for the future 5G of mobile radio networks by the IMT 2020 standard are examined. They include inter alia the technique DIDO (Distributed Input Distributed Output), a perspective resource allocation for future wireless communication networks. The technology should only augment the existing GERAN, UTRAN, SAE and IMS mobile radio infrastructure of previous generations 2G-4G with a flexible world-wide WLAN, which is operated under use of a data bases for available frequency bands and the Web-based content called DIDO Data Centers. Conclusions. Efficient WLANs as well as DIDO must become a part of 5G systems. By the opinion of some leading companies like Rearden, Microsoft, Samsung, Huawei the method DIDO has to be used as a new resource allocation method for future WLANs. Проблематика. В настоящее время мобильная связь занята предоставлением IP-сервисов и передачей мультимедийного контента из одного места в другое, но уже завтра новое поколение 5G сможет контролировать широкий спектр материальных объектов в реальном времени с только незначительным вмешательством человека. Создается так называемый Интернет вещей «IoT» с множеством новых привлекательных приложений. В данной работе рассматривается новый подход к распределению ресурсов для будущих беспроводных локальных сетей в составе сетей 5G. Цель исследований. DIDO (Distributed Input Distributed Output) – новая технология, направленная на предоставление услуг гибкой многопользовательской беспроводной сети во всем мире в рамках международного согласования и конвенций для используемых частот среди других мобильных технологий для интеграции с 5G. Техника DIDO нацелена на распределение ресурсов для будущих сетей беспроводной связи, которые могут использовать широкий спектр «нетрадиционных» частот от 3 МГц до 30 ГГц и работать независимо друг от друга с полной пропускной способностью и высокой скоростью передачи данных на расстояниях от 100 м до 1000 км. Методика реализации. Был проведен анализ всех известных публикаций, посвященных новому поколению мобильной связи 5G. Исследованы аспекты взаимодействия 5G с WLAN, BT, WSN и другими микро- и пикорадиосетями. Был рассмотрен новый подход к распределению частотных ресурсов для будущей WLAN. Результаты исследований. Представлен обзор, а также обсуждаются основные направления разработки будущих сетей мобильной радиосвязи 5G по стандарту IMT 2020. Они включают, помимо прочего, перспективную технологию DIDO (Distributed Input Distributed Output) для распределения ресурсов для будущих сетей беспроводной связи. Указанная технология должна только расширить существующую инфраструктуру мобильной радиосвязи GERAN, UTRAN, SAE и IMS предыдущих поколений 2G – 4G с помощью гибкой «всемирной» WLAN, которая работает с использованием баз данных для доступных диапазонов частот и с доступом к Web-контенту на основе так называемых DIDO-центров (DIDO Data Centers). Выводы. Эффективные WLAN, в том числе с использованием техноологии DIDO, должны стать частью новых систем поколения 5G. В качестве нового метода распределения ресурсов для будущих беспроводных локальных сетей, по мнению некоторых ведущих компаний, таких как Rearden, Microsoft, Samsung, Huawei, должен использоваться метод DIDO.

This chapter will provide insights on how Third Generation Partnership Project (3GPP) wireless technologies caters to massive machine type communication and Internet of Things (IoT) devices. It will first define what is referred to by machine to machine (M2M) versus IoT. Then it will outline the requirements and the challenges imposed by massive number of such devices connecting to cellular network. Then it will provide a detailed overview of the solution introduced for such devices using 3GPP wireless technologies (long term evolution [LTE] and evolution of Evolved Packet System [EPS] architecture, Narrow Band Internet of Things [NB‐IoT] with cellular Internet of Things [CIoT] architecture, GSM/EDGE RAN [GERAN] for M2M) in the ecosystem. It will provide insights into how 5G Radio and 5G System architecture are expected to address M2M challenges.

In this paper, a simplified uplink transmission procedure is proposed for reducing energy consumption and improving lifetime of CIoT devices. In the proposed procedure, the CIoT devices register information on their service and traffic to the networks, and the networks statically allocate pre-defined amounts of radio resources when the CIoT devices have requested permission for their uplink transmissions. This paper provides details of the proposed procedure comparing with those of the current GSM procedure, and defines detailed operations of the devices and the networks for the proposed one. This shows that the proposed scheme can effectively support CIoT services on GSM networks.Key words: Machine-Type Communications, Cellular IoT, Energy Consumption, Power Saving` VNa= 6DMC VN 0bT Revised October 23, 2015 ; Accepted October 26, 2015. (ID No. 20150923-06S)Corresponding Author: Min Young Chung (e-mail: mychung@skku.edu)

The scope of this paper is to provide a detailed description of the selected architecture and the functionalities considered for the AROMA project. This project focuses on a heterogeneous radio access network which includes several Radio Access Technologies (RAT) , namely; UMTS Terrestrial Radio Access Network (UTRAN), GSM/EDGE Radio Access Network (GERAN), and Wireless Local Area Network (WLAN). The corresponding Common Core Network (CN) is considered to provide and satisfy different kind of services, thus, different identified services have different QoS, then, so the goal is to study and analyze some algorithms, that best fit in the network in order to enable quality of service (QoS) based on the service demand in the network. Radio Resource Management (RRM) refers to a group of algorithms that are collectively responsible for efficiently utilizing the radio resources within a RAT to provide services with an acceptable level of QoS. Mainly, at present, Radio Resource Management (RRM) algorithms are implemented independently in each RAT. In the meanwhile, The Common RRM (CRRM) strategy, has been proposed in the literature to coordinate radio resources utilization among a number of RATs in an optimized way. This paper analyze CRRM solutions with particular attention on implementations. Starting from an analysis of the state of the art, the most interesting solutions have been critically analyzed and then some in depth investigations on some of the identified solutions have been performed.

This paper presents a network model based on a NGN architecture applied to the Mexican rural context and deployed over the optical fiber backbone of the e-Mexico (now Mexico Conectado) system. The proposed model considers the integration of access networks for GERAN, UTRAN and E-UTRAN users, allowing also the interconnection with circuit switched networks. We use the E model proposed by ITU-T to maintain a minimum level of voice quality R>70. Additionally, we calculate the estimated bandwidth consumption during the seven phases that SIP requires establishing a telephone call on IMS networks. Our model includes the calculation of the most significant NGN parameters, taking into account the use of an optimal codec, a percentage of packet loss and link utilization level, for the conditions of the Mexican rural environment and the e-Mexico (now Mexico Conectado) system infrastructure.

The bunyaviral monogeneric family Nairoviridae currently includes 12 species for 35 distinct viruses. Here, we present the complete genome coding sequences of an additional seven nairoviruses. Five of them can be assigned to established species, whereas two of them (Artashat and Chim viruses) ought to be assigned to two novel species.

The explosive growth of mobile communications, and the overly crowded and expensive spectrum have pushed both system engineers and operators to make their systems as spectrally efficient as possible in order to accommodate the increasing traffic demand. This article is a tutorial introduction to the orthogonal subchannel (OSC) technique. OSC was adopted to improve the capacity of the GSM/EDGE radio access network GERAN, and it is a new concept in which two users can simultaneously share the same GSM radio resource (time slot and frequency) in both the downlink and in uplink directions. Potentially, OSC could not only provide increased network capacity, but also reduce network-associated costs through more efficient usage of hardware and spectrum resources. In addition, this article presents some challenges related to this method, as well as solutions and their respective impact. The results provided herein may contribute to guidelines for network dimensioning and optimization, as well as list potential enhancements to the OSC radio resource management mechanisms needed to further exploit the benefits of OSC. Currently, in real OSC network deployments a capacity gain of 50 percent has been achieved at the cell level. As an indication of the importance of OSC, GSMA awarded it (called Quad Rate) the Best Technology Breakthrough award at Mobile World Congress 2012 [1].

Problem statement: The Next generation wireless networks are heterogeneous in nature where different Radio Access Technologies (RAT) coexists in the same coverage area. The user terminal should be able to pick the best access technology such as Wireless Local Area Network (WLAN), Wireless Wide Area Networks (WWAN), the Universal Mobile Telecommunication Systems (UMTS) and the Global System for Mobile Telecommunication (GSM)/Enhanced Data rate for GSM Evolution (EDGE) Radio Access Network (GERAN) at its current location and use the access technology seamlessly for the provision of desired service. The goal is to select the most suitable Radio Access Technology (RAT) for each user. It is important that suitable decision making algorithm should be designed such that all the important characteristics of the system are taken into account when making the radio access selection. Approach: For this reason, this research work proposes a methodology to select the best access network among WLAN and WWAN under the input criteria Signal Strength of both networks, speed of the mobile terminal and network coverage of both networks and Quality of Service (QoS). Hence, in this work, a new hybrid multi objective decision making algorithm employing weighing function and particle swarm optimization is proposed for fuzzy based Radio Access Technology selection of Heterogeneous wireless networks. Results: The end results indicate that the proposed algorithm outperforms better than the existing methods. Conclusion: Inferences from the results indicate that by using the proposed algorithm, best RAT can be selected for the user with a minimal time constraint.

In mobile networks, location area (LA) planning has a strong influence on network performance. This paper addresses the problem of optimising an existing LA plan in a live GSM-EDGE radio access network (GERAN) based on statistical measurements. Unlike prior work, where the quality of an LA plan was assessed based on the number of location update and paging requests, the main focus in this paper is on estimating the impact of changing the LA plan on the air-interface signalling load. For this purpose, a performance model is proposed to estimate changes in the traffic load in dedicated signalling channels. With such a model, it is possible to estimate the change that a new LA plan will cause in terms of the required number of signalling channels in the whole network, providing an indication of the capacity benefit obtainable, which is a more significant figure of merit for operators. Model assessment is carried out based on measurements taken before and after changing the LA plan of a limited geographical area in a live network. Then, a comparison of several LA re-planning algorithms is performed over measurements in a larger area by using the proposed performance model. Results show that the signalling traffic (and, hence, the required signalling resources) can be significantly reduced by improving the existing LA plan in a live GERAN system.

Over the last few years, graph partitioning has been recognized as a suitable technique for optimizing cellular network structure. For example, in a recent paper, the authors proposed a classical graph partitioning algorithm to optimize the assignment of cells to Packet Control Units (PCUs) in GSM-EDGE Radio Access Network. Based on this approach, the quality of packet data services in a live environment was increased by reducing the number of cell re-selections between different PCUs. To learn more about the potential of graph partitioning in cellular networks, in this paper, a more sophisticated, yet computationally efficient, partitioning algorithm is proposed for the same problem. The new method combines multi-level refinement and adaptive multi-start techniques with algorithms to ensure the connectivity between cells under the same PCU. Performance assessment is based on an extensive set of graphs constructed with data taken from a live network. During the tests, the new method is compared with classical graph partitioning approaches. Results show that the proposed method outperforms classical approaches in terms of solution quality at the expense of a slight increase in computing time, while providing solutions that are easier to check by the network operator.

GERAN (GSM-EDGE Radio Access Network) operators have traditionally used the Erlang B formula to estimate the number of signalling channels on a per-cell basis. Thus, it is assumed that the network behaves as a loss system with Poisson arrivals. However, the presence of automatic retrial mechanisms and correlated arrivals in these channels suggests that these assumptions might not be valid. This paper presents a performance analysis of the Stand-alone Dedicated Control CHannel in GERAN. Preliminary analysis shows that the Erlang B formula underestimates congestion and blocking on this channel. To address this issue, a queueing model with retrials and correlated arrivals is proposed, where correlation between arrivals is modelled by a simple Markov-Modulated Poisson Process. The proposed model can be tuned on a per-cell basis by statistics in the Network Management System. Model assessment is based on performance statistics from a live GERAN system. Results show that a simple retrial queueing model fails to explain blocking in cells with a large number of channels. These limitations are overcome by adding correlated arrivals in the retrial model.

In a mobile communications network, the uneven spatial distribution of traffic demand can be dealt with by redefining cell service areas. When resizing cells, network operators often aim at equalizing call blocking rates throughout the network in the hope that this will maximize the total carried traffic in the network. In this paper, an analytical teletraffic model for the traffic sharing problem in GSM-EDGE radio access network (GERAN) is presented. From this model, a closed-form expression is derived for the optimal traffic sharing criterion between cells. Using this expression, it can be shown that balancing call blocking rate between adjacent cells is not the optimal strategy. Results show that using the optimal traffic sharing criterion instead of balancing blocking rates across the network can increase network capacity, even under restrictions in the cell resizing process.

The evolved 3GPP system is a hybrid mobile network architecture supporting several radio access technologies and several mobility mechanisms. In this article we briefly review the architecture and key components of this system, with particular emphasis on how it can support voice call mobility in several deployment scenarios. First, we present the so-called single-radio voice call continuity mechanisms that enable mid-call handover of VoIP calls from E-UTRAN access to the legacy UTRAN/GERAN or lxRTT access. Then we focus on deployment scenarios that do not support voice services on E-UTRAN and present the so-called fallback mechanisms that enable handover from E-UTRAN to UTRAN/GERAN or lxRTT at the beginning of a voice call. Finally, we address the application- layer voice call handover mechanisms enabled by the IP multimedia subsystem. Our conclusion is that the next generation of 3GPP systems are highly sophisticated mobile communication systems that support extended voice call mobility mechanisms, capable of addressing all commercial deployment needs.

A key aspect of the 3GPP system architecture evolution is the specification of an evolved packet core that supports multiple access networks. The EPC enables operators to deploy and operate one common packet core network for 3GPP radio accesses (E-UTRAN, UTRAN, and GERAN), as well as other wireless and wireline access networks (e.g., eHRPD, WLAN, WIMAX, and DSL/Cable), providing the operator with a common set of services and capabilities across the networks. A key requirement of the EPC is to provide seamless mobility at the IP layer as the user moves within and between accesses. This article provides an overview of the EPC specifications that use a network-based mobility mechanism based on Proxy Mobile IPv6 to enable mobility between access networks. An important facet of providing seamless mobility for a user's sessions across technologies is to ensure that quality of service is maintained as the user moves between accesses. An overview of the "off-path" QoS model to supplement PMIPv6 is also provided.

This paper addresses the problem of radio access technology (RAT) selection in heterogeneous multi-access/multi-service scenarios. For such purpose, a Markov model is proposed to compare the performance of various RAT selection policies within these scenarios. The novelty of the approach resides in the embedded definition of the aforementioned RAT selection policies within the Markov chain. In addition, the model also considers the constraints imposed by those users with terminals that only support a subset of all the available RATs (i.e. multi-mode terminal capabilities). Furthermore, several performance metrics may be measured to evaluate the behaviour of the proposed RAT selection policies under varying offered traffic conditions. In order to illustrate the validation and suitability of the proposed model, some examples of operative radio access networks are provided, including the GSM/EDGE Radio Access Network (GERAN) and the UMTS Radio Access Network (UTRAN), as well as several service-based, load-balancing and terminal-driven RAT selection strategies. The flexibility exhibited by the presented model enables to extend these RAT selection policies to others responding to diverse criteria. The model is successfully validated by means of comparing the Markov model results with those of system-level simulations.

As the wireless industry makes its way to the next generation of mobile systems, it is important to engineer solutions that enable seamless integration of emerging 4G access technologies within the currently deployed and/or evolved 2G/3G infrastructures. In this article we address a specific case of such a seamless integration, that of mobile WiMAX in evolved 3GPP networks. In this context we investigate the architecture and the key procedures that enable this integration, and we also introduce a novel handover mechanism that enables seamless mobility between mobile WiMAX and legacy 3GPP access, such as UTRAN or GERAN. The core characteristic of this novel handover mechanism is that mobile terminals do not need to support simultaneous transmission on both WiMAX and 3GPP accesses; therefore, it mitigates the RF coexistence issues that exist otherwise and improves handover performance. In addition, we provide a brief overview of mobile WiMAX and the evolved 3GPP network technologies, and we set the appropriate background material before presenting our proposed handover mechanism. Our main conclusion is that integrating mobile WiMAX in evolved 3GPP networks is a compelling approach for providing wireless broadband services, and mobility across WiMAX and 3GPP access can become seamless and efficient with no need for mobile terminals to support simultaneous transmission on both types of access.

In this paper, an innovative mechanism to perform joint radio resource management (JRRM) in the context of heterogeneous radio access networks is introduced. In particular, a fuzzy neural algorithm that is able to ensure certain quality-of-service (QoS) constraints in a multicell scenario deployment with three different radio access technologies (RATs), namely, the wireless local area network (WLAN), the universal mobile telecommunication system (UMTS), and the global system for mobile communications (GSM)/Enhanced Data rates for GSM Evolution (EDGE) radio access network (GERAN), is discussed. The proposed fuzzy neural JRRM algorithm is able to jointly manage the common available radio resources operating in two steps. The first step selects a suitable combination of cells built around the three available RATs, while the second step chooses the most appropriate RAT to which a user should be attached. A proper granted bit rate is also selected for each user in the second step. Different implementations are presented and compared, showing that the envisaged fuzzy neural methodology framework, which is able to cope with the complexities and uncertainties of heterogeneous scenarios, could be a promising choice. Furthermore, simulation results show that the reinforcement learning mechanisms introduced in the proposed JRRM methodology allow guaranteeing the QoS requirement in terms of the so-called user dissatisfaction probability in the presence of different traffic loads and under different dynamic situations. Also, the proposed framework is able to take into consideration different operator policies as well as different subjective criteria by means of a multiple decision-making mechanism, such as balancing the traffic among the RATs or giving more priority to the selection of one RAT in front of another one.

Cellular network traffic is unevenly distributed both in time and space, which greatly complicates network dimensioning. As a result, some cells in the network are permanently congested, while others are underutilized. In a previous paper, the authors showed that this problem can be effectively solved in GSM/EDGE Radio Access Networks (GERAN) by modifying handover boundaries. However, several drawbacks prevent operators from fully exploiting the potential of this technique. This paper investigates the limitations of current traffic-sharing approaches with tight frequency reuses in GERAN. To deal with such limitations, an algorithm is proposed to jointly optimize handover margins and signal-level constraints based on network statistics for traffic sharing in GERAN. A complementary algorithm is proposed to adjust cell (re)selection offsets to minimize the number of handovers. Simulation results show that the proposed method achieves a significant reduction in call blocking without excessive call quality impairment or increase of network signaling load when compared to the current approaches. More traffic can thus be handled without the need for any hardware upgrades, providing a cost-effective means to increase network capacity.

In GSM/EDGE Radio Access Networks (GERAN), the number of neighbor cells defined per cell for handover purposes is limited. Due to the large number of cells and, consequently, neighbor cells in the system, neighbor cell management proves a complex and time-consuming process during network operation. Hence, it is very likely that, on some cells, important neighbor cells are missing. This paper outlines a new approach for determining these missing neighbors, based only on information from the network management system. Thus, the need for propagation data from network planning tools is circumvented, which makes the method especially suitable for the operational stage of an existing network. Results from the application of the method in a live network show its capability to spot such missing neighbors. Although performance benefits from the method are rather limited for the entire network, significant benefits can be obtained on individual cells.

Different user segments have various requirements and expectations towards the performance of mobile networks. Subscribers having experienced the high quality of UMTS networks desire to maintain high speech quality and excellent data throughput also in areas of missing UMTS but existing GSM coverage. In GSM networks a privileged treatment of UMTS subscribers by means of proper resource allocation provides a substantial quality improvement with respect to standard GSM subscribers. This strategy allows network operators to reduce the performance gap between both network areas experienced by UMTS subscribers. A detailed study on the performance of circuit switched speech and packet data services has been performed based on system level simulations. The results show significant speech quality advantages for users with dual-RAT terminals compared to standard GSM users as well as notably higher data throughput rates.

The Enhanced Voice Services (EVS) codec was standardized by 3GPP in 2014. This codec offers significant gains in voice quality, efficiency, channel error robustness over any other existing speech codec and far better music quality. Operators run voice services on a large installed base of 3GPP Circuit-Switched (CS) 2G (GERAN) or 3G (UTRAN) radio networks. These networks offer mobile voice service either as HD voice using the AMR-WB codec, or as traditional narrowband (NB) voice service, based on the AMR codec. Voice over LTE (VoLTE) is currently being deployed throughout the world with HD Voice. The EVS codec will be first introduced as a straightforward VoLTE upgrade. It is also expected that EVS will be deployed over 3G CS networks. This paper describes system aspects relating to EVS codec introduction in VoLTE and CS networks as well as interworking and mobility with legacy systems and services.

In this paper, different error protection strategies in different protocol layers are discussed, in order to reliably broadcast multimedia data within existing wireless networks. In particular, we investigate the performance of additional forward error correction (FEC) in the physical layer, the radio link control (RLC) layer, and the RTP layer for multimedia broadcast and multicast services over GERAN systems. Advantages and drawbacks when applying error correction in different layers are shown. We introduce a simple receiver modification, referred to as permeable-layer receiver (PLR), which exploits traditionally useless information at the receiver, while the transmitter is kept unchanged. Significant performance gains are reported. Finally, the application to H.264/AVC based wireless video broadcast is discussed and the performance of different system designs for video transmission is shown.

Half-Rate (HR) channel coding can be used to deal with temporary traffic peaks in Global System for Mobile Communications (GSM)/Enhanced Data Rates for Global Evolution (EDGE) Radio Access Networks. Since operators have to pay for the use of HR codecs, the number of transceivers on which HR can be used is normally limited. An algorithm that optimizes the assignment of a limited number of HR codecs in a network is presented. The final solution obtained with the greedy algorithm proposed has proved to be optimal. Subsequent application of the algorithm in a real environment shows significant performance benefits in terms of network congestion reduction in comparison to the current approach used by network operators.

A major enhancement of GERAN is the flexible layer one (FLO) concept, due to be introduced in Release 6 of the 3GPP standards. FLO greatly simplifies the introduction of new services to the GERAN system, allowing "tailor-made" QoS provision, significantly enhancing GERAN's flexibility and ensuring that it can continue to provide services on a par with other 3G systems. Other benefits of FLO include improved link layer performance when carrying services such as voice over IP, improved multiplexing ability, and spectral efficiency. This article introduces the FLO concept, how it works, the changes it requires, and its benefits and disadvantages.

71% of the world's digital mobile communications subscribers use GSM. many incorrectly consider the system as approaching its end, particularly with the advent of 3G, because it is thought to be voice-centric with low performing data capabilities. However, GSM is far from dead, and is in fact being advanced in a manner that finds it on par with 3G technologies. The manifestation of the GSM radio access network, "GSM/EDGE Radio Access Network" (GERAN) is now considered by the International Telecommunications Union as a 3G technology in its own right. It is standardised by the same Organisation as UTRAN (UMTS Radio Access Network), and has been positioned as a complementary component of the overall UMTS (Universal Mobile Telecommunications System) communications system.

The race for higher data rates in wireless systems has produced a multiplicity of radio access methods to fulfill the quality of service needs for the next generation of mobile devices. This document presents an analysis of GERAN, UTRAN, WLAN, and Bluetooth as possible methods of accessing services via a wireless device. In light of the results, meaningful combinations for radio access methods of wireless devices are elaborated.

In GSM-EDGE radio access network (GERAN), the assignment of base stations to base station controllers has a strong impact on network performance. In this paper, an exact method is proposed to improve an existing assignment of base stations to base station controllers. The aim is to minimize the number of handovers between base station controllers given a maximum number of base stations re-allocations. Results from a real case study show that the proposed method outperforms classical re-partitioning approaches in terms of solution quality.

In cellular networks, location managements has a strong impact on signaling load. To minimise mobility-based signaling traffic. Location Areas (LAs) have to be defined correctly. Large LAs increase paging traffic, while small LAs increase location updates. Thus, operators have to trade-off these two constraints to maximize network performance. Several authors have proposed selective paging to reduce paging load. This paper describes an intelligent paging algorithm based on most-recent interaction data. Trial results in a live GSM-EDGE Radio Access Network (GERAN) show that the algorithm can reduce paging traffic significantly, while keeping paging success rates almost unaltered.

In GSM EDGE radio access network (GERAN), the assignment of cells to packet control units within a base station-controller is of key importance to optimize the quality of service experienced by end users. In this paper, a novel methodology is presented to optimize this assignment by means of graph partitioning theory. The proposed algorithm aims at minimising the number of cell re-selections between cells on different packet control units based on handover information. Results from the application of the method in a live network show its capability to improve end-user performance in terms of service delay and application throughput.

The evolution of wireless networks has led to the deployment of different Radio Access Technologies (RATs) such as GSM/EDGE Radio Access Network (GERAN), UMTS Terrestrial Radio Access Network (UTRAN) and Long Term Evolution (LTE). Next Generation Wireless Networks (NGWNs) are predicted to interconnect various Third Generation Partnership Project (3GPP) Access Networks with Wireless Local Area Network (WLAN) and Mobile Worldwide Interoperability for Microwave Access (WiMAX). A major challenge is how to allocate users to the most suitable RAT for them. An intelligent solution will lead to efficient radio resource utilization, maximization of network operator’s revenue and increasing in the users’ satisfactions. Common Radio Resource Management (CRRM) was proposed to manage radio resource utilization in heterogeneous wireless networks. This paper discusses the need of CRRM for NGWN. Then, the paper presents a comparison between implementing or not the CRRM in heterogeneous wireless networks. After that, the interaction between RRM and CRRM entities is discussed. Then, different approaches for the distribution of RRM and CRRM entities among the Core Network (CN), RATs and User Terminals (UTs) will be presented. Finally, a comparison between distributed and centralized algorithms is presented.

Antenna downtilting is often mentioned in the literature as a powerful method for improving network performance in cellular systems. The antenna elevation angle on a number of GSM EDGE radio access network (GERAN) cells has been modified to quantify the impact of this method in a real network. In addition, a novel approach to prioritizing the cells to be tilted, which uses network statistics only, has been tested. Trial results indicate that downtilting can improve certain performance aspects, especially those related to signal quality, but not all of them on every cell.

This paper is focused on evolved GSM/EDGE systems complying to the new feature Voice services over Adaptive Multi-user channels on One Slot (VAMOS), recently introduced in the 3GPP GSM/EDGE radio access network (GERAN) standard. VAMOS enables the transmission of two GSM voice streams on the same radio resource through the so called Orthogonal Sub Channel (OSC) multiple access technique which aims at doubling the number of users served by a cell. When adopting this feature, the GSM network experiences a mixture of in-cell and out-of-cell interference which has to be handled by advanced receivers with interference rejection capabilities. In this paper, a novel two-stage receiver is proposed and tested for the uplink of GSM VAMOS systems. The new scheme combines a pre-filtering stage for out-of-cell interference mitigation with a multi-user detector (MUD) for joint equalization of the two multiplexed OSC streams. The approach is suited for either single-antenna or multi-antenna base stations and can accommodate multiple filters for each user to cope with complex multipath propagation scenarios. The new solution is compared with other existing interference cancellation techniques here applied to the specific OSC scenario. Numerical results show significant performance gains in realistic multi-cell simulated scenarios.

MUROS using high order modulation (HOM) is one of techniques for improving speech efficiency for 3GPP GERAN evolution. However, the conventional HOM for MUROS scheme shows high complexity because of the change of modulation format. Therefore, in this paper, an improved HOM scheme for the MUROS is proposed which employs a repetition transmission using surplus bits.

Increasing attention has been drawn in Machine Type Communications (MTC), also known as Machine to Machine (M2M) Communications, since it enables implementation of new services, and expansion of revenue sources for mobile equipment manufacturers and mobile network operators. This potential is high, but some issues have to be solved to enable the wide application of MTC services, especially those which could request connections in a synchronized manner. In GSM networks, synchronized channel requests can result in signaling channel overload, which would delay the access procedure for all users trying to access the network. This paper presents a solution for this problem, in which devices connecting in a periodical manner request a future network access already during a previous connection. Simulation results have shown that by using this technique, overload on the access channels is reduced, improving the access delay of normal users and enabling more MTC devices to be included in the network.

Due to the flexibility and simplification, the fuzzy logic control (FLC) is chosen to make effective utilization of resources. The proposed Algorithm is divided into four parts: traffic classification, resource estimation for reservation, admission control and RAT selection. This combined fuzzy logic and multi-attribute decision making (MADM) based algorithm can make proper initial RAT selection, horizontal handoff, vertical handoff, admission control and load balancing. The MADM based RAT selection also has better efficiency than the traditional RRM mechanisms. By considering three kinds of traffic, voice, video and data respectively, the proposed scheme provides lower new call blocking probability and handoff call dropping probability in the heterogeneous wireless network that includes GERAN (GSM/EDGE Radio Access Network), HSPA (High-Speed Packet Access) and Mobile WiMAX (Worldwide interoperability for microwave access) RATs.

Machine type communications have emerged with new types of applications and revenue sources both for network operators and cellular/network equipment companies. This new kind of service may increase significantly the number of devices accessing the network in the next few years, and could have some impacts over the current services, namely normal voice and data services. One important concern is related to effects of extreme cases where MTC devices may act in a synchronized way. In GSM networks, the signaling capacity may be temporarily blocked, limiting the access of normal services for some seconds, or even minutes. This paper proposes one solution for overload problem caused by MTC device synchronization using the Orthogonal sub- channels technique (OSC). Statistical analysis over the effects of synchronized MTC devices are used to provide an overview on the achievable access procedure delay reduction when using this technique. The proposed technique has proven to decrease the average delay of normal services by 70% and to reduce by 50% the overload period of the signaling channels.

Increased attention has been drawn to machine type communication (MTC) lately, which represents important extension for user functionality in today's technologies, as well as an important potential for marketing expansion. GERAN studies over MTC has mainly focused on applications requiring low throughput and wide coverage such as smart meter, which could cause some impacts over normal data users if operating in a synchronous manner. This paper proposes a new methodology for studying the impact on signaling channels when mixture of synchronous and asynchronous traffic is present in the network. This is based on statistical analysis, considering signaling accessing attempts as driven by a Poisson process. In this approach successive random access attempts by the mobile stations are considered as well as the response on the network side. First implementation is held for GSM/GPRS network, although generalization of the method for other technologies is possible. The simulated results show potential problems to be solved when a large number of synchronized users is present. Additionally, an analysis on the effects of the different levels of synchronization and the addition of extra signaling channels is included. Results also point out possible development paths that could be taken when designing new features to make networks more robust to synchronized traffic.

Hierarchical network structuring will be a central issue in future cellular networks. In the literature, many graph partitioning methods have been proposed to assign network elements to controllers to minimize network signaling. This paper presents two refinements to such methods, namely the connectedness and site constraints, to improve the spatial consistency of solutions, which is key for easy checking by the operator. Assessment is based on real problem instances of the assignment of base stations to packet control units in GSM-EDGE Radio Access Network (GERAN). Results show that fragmentation and overlapping in the final solution can be greatly reduced, while degrading the network performance only marginally.