QoS Reliability in GPRS Systems

In this article, the performance and capacity gain achievable with quality of service (QoS) management in packet switched radio networks based on the General Packet Radio Service (GPRS) are examined. Both the functions defined in the GPRS specification for QoS support and implementation-specific strategies for subscriber- and application-based Connection Admission Control (CAC) and scheduling are introduced. The feasibility of QoS provisioning in mobile core networks with use of DiffServ compared to present IP technology realizing a pure Best-effort service is examined in addition. To achieve this, simulation results of GPRS performance and system measures for different load situations are produced with the simulation tool GPRSim that models the realistic traffic behavior of a GPRS network.

General packet radio service (GPRS) is a part of the evolution path towards 3G. This paper investigates the effect of using two representative scenarios: a macro cellular system operating from a high altitude platform line of sight system and a terrestrial non-line-of-sight system, in each case a packet-based such as GPRS system is considered. The macro cellular layer will serve as second server to the mobile data terminals located in a microcellular layer, both layers form a Multi-layer cellular system. A comparison between GPRS system using only microcellular structure and when using both microcellular and macro cellular structures is evaluated. A simulator model was developed to study the behavior of data transmission between a GPRS server and data terminals via air interface. Simulation results show the validity of using macro cells to serve as a second layer, and how this can enhance the GPRS system performance.

This paper presents the design and analysis of general packet radio service (GPRS)-wireless local area network (WLAN) mobility gateway (GWMG) for the integration of GPRS and WLANs. The interworking between GPRS and WLANs is achieved by the GWMG that resides on the border of GPRS and WLAN systems. The design goal is to minimize the modifications in GPRS and WLANs as both systems are already widely available. By deploying the GWMG, users can seamlessly roam among the two systems. Unlike other related work, the proposed GWMG could be used when either the GPRS or WLAN is a user's home network. Both mathematical analysis and simulation are developed to analyze the performance. The proposed GWMG has also been implemented in a testbed comprising a commercial GPRS system. The results show that the GWMG could achieve a design goal that will effectively integrate GPRS and WLANs.

Multi-access edge computing (MEC) is an emerging computing paradigm that brings services from the centralized cloud to nearby network edge to improve users' Quality of Experience (QoE). As massive services with dynamic Quality of Service (QoS) are available in MEC, it becomes challenging for users to find reliable services that satisfy their needs. Therefore, service recommendation technology is urgently needed in MEC. Although existing service recommendation methods work well on recommending popular services that users might be interested in, they fail to recommend services with reliable QoS in the MEC environment. To tackle this issue, an accurate and reliable service recommendation (ARSR) approach based on bilateral perception is proposed, which aims to proactively recommend reliable services by perceiving both users' service demands and multi-QoS of candidate services. ARSR consists of three main steps. First, a user's service demand is estimated by a context-aware service demand prediction method based on an improved online deep learning model. Then, multiple QoS attributes of candidate services are forecasted by a multidimensional contexts-aware QoS prediction method based on an improved multi-task deep neural network. Finally, the optimal service is recommended to the user based on the predicted QoS. Extensive experiments have been carried out to verify the proposed approach and to prove its performance superiority.

The internet currently hosts a large number of web services with highly volatile quality of service (QoS), which makes it difficult for users to quickly access highly reliable online services. Hence, the selection of the optimal service composition based on fast and reliable QoS has emerged as a challenging and popular problem in the field of service computing. In this paper, we propose a service selection approach based on QoS prediction. We consider historical QoS information as time series and predict QoS values using the autoregressive integrated moving average model, which can provide more accurate QoS attribute values. We then calculate the uncertainty in the prediction results using an improved coefficient of variation to prune redundant services. In order to downsize the search space, we employ Skyline computing to prune redundant services and perform Skyline service selection using 0-1 mixed-integer programming. Experimental results based on real-world dataset showed that our approach yields satisfactory performance in terms of reliability and efficiency.

General Packet Radio service (GPRS) is a part of the evolution path towards 3G. This paper investigates the effect of using two representative scenarios: a macro cellular system operating from a high altitude platform line of sight system and a terrestrial non-line-of-sight System, in each case a packet-based such as GPRS system is considered. The macro cellular layer will serve as second server to the mobile data terminals located in a microcellular layer, both layers form a Multi-layer cellular system. A comparison between GPRS system using only microcellular structure and when using both microcellular and macro cellular structures is evaluated. A simulator model was developed to study the behavior of data transmission between a GPRS server and data terminals via air interface. Simulation results show the validity of using macro cells to serve as a second layer, and how this can enhance the GPRS system performance.

The intricacy of real-time data service management increases mainly due to the emergence of applications operating in open and unpredictable environments, increases in software complexity, and need for performance guarantees. In this paper we propose an approach for managing the quality of service of real-time databases that provide imprecise and differentiated services, and that operate in unpredictable environments. Transactions are classified into service classes according to their level of importance. Transactions within each service class are further classified into subclasses based on their quality of service requirements. In this way transactions are explicitly differentiated according to their importance and quality of service requests. The performance evaluation shows that during overloads the most important transactions are guaranteed to meet their deadlines and that reliable quality of service is provided even in the face of varying load and execution time estimation errors

We introduce a variety of mechanisms to enable scalable, adaptive, and reliable quality of service (QoS) guarantees across heterogeneous networking environments. The resultant scalable resource reservation scheme (SRRS) is the first resource management scheme that provides efficient fault protection based on the virtual reservation mechanism and a penalty-based adaptable reservation mechanism, so that QoS can continue to be guaranteed in the presence of faults without wasting expensive network resources unnecessarily. Based on the proposed geographical reservation mechanism and virtual IP addressing, SRRS can enable QoS guarantees in ad hoc mobile wireless networks. Also, resource reservation and allocation in SRRS are adaptive to the networking environments so that wireless QoS-guarantee issues can be resolved in the presence of mobility, making SRRS suitable for wireless mobile networks. We evaluate the performance of SRRS based on simulation and analysis, and show that SRRS can achieve considerably lower blocking rates as compared to previous reservation protocols.

Focusing on data reliability, we propose a control theory centric approach designed to improve transient error resilience in shared caches of emerging multicores while satisfying performance goals. The proposed scheme takes, as input, two quality of service (QoS) specifications: performance QoS and reliability QoS. The first of these indicates the minimum workload-wide cache (L2) hit rate value acceptable, whereas the second one captures the reliability bound on an application basis, with the help of a metric called the Reads-with-Replica (RwR). We present an extensive experimental evaluation of the proposed scheme on various workloads formed using the applications from the SPEC2006 benchmark suite. The proposed scheme is able to satisfy, in most of the tested cases, both performance and reliability QoS targets, by successfully modulating the total size of the data replication area and partitioning of this area among the co-runner applications. The collected results also show that our scheme achieves consistent improvements under different values of the major simulation parameters.

The wireless networks are requiring higher transmission speed and more reliable QoS, especially the 5G systems. Different network providers will run different quality of transmission services and the user could choose the suitable set. In this work, considering the varieties of transmission types and price, we propose a novel game theoretical solution of downlink resource allocation, the fusion of different types of transmission could significantly reduce the transmission price under the constraint of system Quality of Service (QoS). Simulation results prove the fact that by using our proposed game theoretical method, the price of the downlink transmission could be reduced up to 37% under the constraint of QoS, the expense is the time consumption and the signal processing delay.

In field of service design, the research and application of service quality plays an important role in the development and competition of enterprises by establishing brand image and generating market effect. Therefore, experts in management and marketing have studied it and found that the quality of service in the industry has a great impact on consumer satisfaction, consumer experience and brand loyalty. Based on the research and development of the concept of service quality, PZB, a famous American marketing expert team, established SERVQUAL (SQ) model through the test of retail cases, and constantly revised and improved it, which was applied to multiple service industries. Through literature review, this paper analyzes the application of SERVQUAL model in China and abroad, mainly involving retail industry, medical service industry, e-commerce industry, tourism service industry and other service fields. The study found that SERVQUAL model plays a guiding role in evaluating the management of emerging enterprises, consumers’ preference for services, and resource allocation of service industries in developing countries. In addition, this paper compares the application of SERVQUAL (SQ) model and its derivative SERVPERF (SP) model in the service field, and finds that SP model is mainly a result-oriented quality of service study, while SERVQUAL model is mainly a result-oriented quality of service study based on process dynamic change. In the multi-field studies, it is found that SERVQUAL model, as a common basic model, combines the Fuzzy theory, Functional quality deployment and Kano model to comprehensively evaluate the service quality in the application field and provide decision support for enterprise development. Finally, this article discusses and summarizes the study of service quality, revises and improves the research model, and looks forward and proposes future service quality studies to provide more market and social value to service industry.

This study aims to analyze the influence of brand image and service quality on members’ decisions to obtain productive financing at Baitul Maal wat Tamwil (BMT) Al-Barokah Kaladawa, Tegal. The research is motivated by the vital role of BMTs in providing sharia-compliant financing access for communities underserved by conventional financial institutions, and the need to strengthen brand image and service quality amidst increasing competition among Islamic microfinance institutions. This study employs a quantitative associative approach. Data were collected through questionnaires distributed to 100 active members of the BMT and analyzed using multiple linear regression with SPSS. The results indicate that brand image has a positive and significant effect on members’ decisions in choosing productive financing. Similarly, service quality shows a positive and significant influence on financing decisions. Simultaneously, both variables explain 60% of the variation in members’ financing decisions. These findings suggest that strengthening a sharia-based brand image and improving responsive, empathetic, and reliable service quality can enhance members’ decisions to use BMT’s financing products. This study contributes theoretically to the development of Islamic marketing management literature and provides practical implications for BMTs in formulating strategies to improve competitiveness and member loyalty.

Due to the growing interest in mobile data applications, the Global System for Mobile communications (GSM) has been extended by the General Packet Radio Service (GPRS). It allows the transmission of packet data at moderate bit rates using random access channels within the existing GSM infrastructure. This paper analyses the impact of using multiple channels in a GSM system for GPRS packet transmission. Different combinations of frequency reuse and channel coding are evaluated for 1, 4 and 8 packet data channels (PDCH) per cell. A tight frequency reuse of 1, together with a strong error coding scheme was found to provide the highest capacity. The increased trunking efficiency for a system with 8 PDCH yields a capacity gain of about 64% over a system with only 1 channel. The results indicate that mixing circuit and packet switched traffic causes inefficient use of system resources. Since GSM voice services usually require a frequency reuse of 3 or 7, a separate overlaying network for GPRS provides better resource utilization and maximizes the number of users fulfilling the specified quality of service (QoS) requirements.

Quality of Service (QoS) characterizes the non-functional aspects of Web service, which is the key factor for satisfying service users and has to be carefully considered in service oriented architecture. There has been a lot of works on QoS description and service selection by QoS information. However, two issues have not been substantially explored in QoS management-how to collect QoS information from running services, and how to dynamically adapt service provisioning with run-time QoS information. Moreover, current monitoring approaches are focused on monitoring the service interaction in a single domain, while cross-domain monitoring has not been studied yet. In this paper, we present a policy-driven monitoring framework for collecting QoS information and adapting service provisioning for cross-domain service interaction. The monitor is built on our distributed QoS registry-Q-Peer. The monitor is user-centric, metric-oriented, feedback-enabled and loosely-coupled with service providers. Services are observed by capturing interaction messages, so the monitoring approach has no impact to service providers. The framework supports dynamic configuration of monitoring metrics for both single service and cross-domain composite service. It can be used as a reliable third-party QoS monitor for Web services.

The General Packet Radio Service (GPRS) offers performance guaranteed packet data services to mobile users. A dynamic adaptive guaranteed quality-of-service (QoS) provisioning scheme is proposed over GPRS wireless mobile links via the guaranteed QoS media access control (GQ-MAC) protocol and the accompanying adaptive prioritized-handoff call admission control (AP-CAC) protocol to maintain QoS guarantees under the effect of mobile handoffs. The GQ-MAC protocol supports bounded access delay and packet-loss probability for respective delay and loss sensitive traffic, and dynamic adaptive resource allocation for bursty traffic. The AP-CAC protocol provides dynamic adaptive prioritized admission by differentiating handoff requests of different traffic classes with higher admission priorities over new calls via the dynamic multiple guard channels scheme, which adapts the channel capacity limits reserved for the multiple handoff request classes in each radio cell based on the current estimates of their arrival rates derived from the current number of ongoing calls in neighboring radio cells and the mobility pattern.