A High-Capacity Cellular Network by Improved Sectorization and Interleaved Channel Assignment

<span>Security <span>is very apart important for vehicles to prevent the injury as vehicle theft is very common phenomenon now a days. We can ensure the security of our vehicles via monitoring our vehicles 24/7. There are many possible ways to track a vehicle. A few groups do not concern about the users need. Our research is about the tracking vehicle according to user’s demand. We are concerning on low budget, better geographic coordinate and easy user access. The system needs global positioning system (GPS) and global system for mobile telecommunications (GSM) technology. User can access the system by short message service (SMS) on a mobile phone. GSM module communicate with the user and GPS module communicate with satellite to get latitude and longitude coordinate. Location of vehicle's on earth is determined using Google Maps</span>.</span>

This study employed a descriptive survey research design to investigate the level and pattern of the use of GSM cell phones among selected elite class in Abeokuta. A rational-logical-analysed instrument was used to elicit information on the variables studied from purposefully selected sample size of 365 participants drawn from students, academic and administrative staff at Moshood Abiola Polytechnic, Abeokuta; Federal College of Education, Abeokuta and Ogun State Government Ministries. The data elicited were analyzed, frequency count and simple percentages to answer the research questions. The analysis showed that, though there is high level of GSM handsets among selected elite groups in Abeokuta, some functions are being underutilized. In addition, the GSM has great potentials are being used more for entertainment than business purposes. Based on these, it was recommended that GSM service providers and regulators should continuously promote education and business use of all functions of the handsets. This would not only promote their businesses but also the national development.

Queuing networks models are widely used as important tools for the performance modeling and evaluation of both computer systems and communication networks. Exact solutions are generally not attainable except for some special cases. Consequently, numerical techniques and analytic approximations are needed for the study of queuing networks with bursty traffic. This paper presents the performance modeling and evaluation of general packet radio service (GPRS) for wireless global system for mobile telecommunication (GSM) cells with bursty multi-class traffic under a partial sharing scheme (PSS). The model has been developed using a new powerful tool, MOSEL (Modeling, specification and evaluation language), which is based on numerical methods and the Petri-nets. The proposed model has been validated against simulation and those developed using maximum entry (ME), a well established methodology for approximate solutions. Numerical results demonstrate the credibility of our models.

BackgroundMobile phone use and exposure to radiofrequency electromagnetic fields (RF-EMF) from it have been associated with symptoms in some studies, but the studies have shortcomings and their findings are inconsistent. We conducted a prospective cohort study to assess the association between amount of mobile phone use at baseline and frequency of headache, tinnitus or hearing loss at 4-year follow-up.MethodsThe participants had mobile phone subscriptions with major mobile phone network operators in Sweden (n = 21 049) and Finland (n = 3120), gave consent for obtaining their mobile phone call data from operator records at baseline, and filled in both baseline and follow-up questionnaires on symptoms, potential confounders and further characteristics of their mobile phone use.ResultsThe participants with the highest decile of recorded call-time (average call-time >276 min per week) at baseline showed a weak, suggestive increased frequency of weekly headaches at 4-year follow-up (adjusted odds ratio 1.13, 95% confidence interval 0.95–1.34). There was no obvious gradient of weekly headache with increasing call-time (P trend 0.06). The association of headache with call-time was stronger for the Universal Mobile Telecommunications System (UMTS) network than older Global System for Mobile Telecommunications (GSM) technology, despite the latter involving higher exposure to RF-EMF. Tinnitus and hearing loss showed no association with call-time.ConclusionsPeople using mobile phones most extensively for making or receiving calls at baseline reported weekly headaches slightly more frequently at follow-up than other users, but this finding largely disappeared after adjustment for confounders and was not related to call-time in GSM with higher RF-EMF exposure. Tinnitus and hearing loss were not associated with amount of call-time.

In recent years, there has been an increasing public concern about the health implications of electromagnetic (EM) wave exposure with the use of mobile telephones. In this paper, we have evaluated the EM absorption in the human head at GSM 900 MHz (Global System for Mobile telecommunications) and DCS 1800 MHz (Digital Cellular System) radiation. Two models for human head were considered. The first model was normal adult head whereas the second model was normal elderly head. First, a stratified structure of the human head is modeled. Next, a two-dimensional (2-D) cylindrical head model based on finite-difference time-domain (FDTD) method is investigated. Our previous described 2-D FDTD code based on LabVIEW has been utilized. Much attention has been paid to the induced specific absorption rate (SAR) in elderly human head.

An important indicator commonly used to evaluate the quality of a communication link is signal-to-interference ratio (SIR). However, studies in the literature dealing with SIR for orthogonal frequency division multiplexing (OFDM) systems are relatively few. This paper analytically investigates OFDM system performance by including major channel impairments such as excess delay spread, synchronization error, sample timing error, frequency offset, and time-varying fading. We derive a closed-form expression for SIR, accounting for both variations of inter-carrier interference (ICI) and inter-symbol interference (ISI) with the number of subcarriers, and the susceptibility to channel impairments. A condition relating peak ISI to peak ICI is derived. An expression quantifying the impact of synchronization error in ISI is obtained. SIR behavior with respect to the tradeoff among numbers of subcarriers and other system parameters are investigated. A numerical method, as well as a polynomial equation for an analytical solution, is formulated to find the optimal number of subcarriers for a given set of constraints. We demonstrate the variations of SIR with various parameters and analyze the leakage of power (unwanted power distribution across subcarriers).

We considered call admission control (CAC) algorithms both for the reverse and forward link with multiple types of services requiring different SIRs (signal to interference ratio) and transmission rates. In the forward link, a call is admitted if the requested power is available at the base station, whereas in reverse link, a call is admitted if the interference level is below a certain revel that guarantees the communication quality. First, the optimal power ratio that characterizes the effect of different service types is considered. Then a simple CAC algorithm is proposed and evaluated through simulation. With these CAC algorithm, we compare the capacity of forward link and reverse link for commonly used SIR equations.

With the success of wireless sensor networks (WSNs), traditional engineering and infrastructure industries are starting to develop solutions using WSN technologies. One of the main challenges of designing and developing WSNs for industrial monitoring and control is satisfying their strict reliability requirements. In this paper, we present a network-level reliability model, namely, end-to-end data delivery reliability (E2E-DDR), for estimating and optimizing the reliability performance of WSNs. In the E2E-DDR model, a framework is presented for capturing the mapping function between the packet reception ratio, background noise, and received signal strength (RSS). We use an alpha-stable distribution to accurately represent the background noise and a modified log-normal path loss model to more realistically describe the RSS. We also report a comprehensive performance evaluation performed by applying the E2E-DDR model in a real-world case study to estimate the network-level reliability and optimize the WSN deployment parameters. Note to Practitioners —The goal of this paper is to improve the estimation and optimization of the network-level reliability performance of industrial wireless sensor networks (WSNs) to satisfy their strict control requirements. In harsh industrial application scenarios, many factors affect radio link quality, such as RF transmit power, communication distance, and random background noise. Existing link quality estimation approaches mainly focus on providing a smoothed estimation of radio link quality without any solution for optimizing communication reliability to satisfy certain requirements. This paper suggests a new approach in which WSN nodes are used to measure and estimate the parameters of the scenario in which the nodes will be deployed and then to estimate and optimize the worst case reliability (which is a lower-bound value rather than a smoothed value) to ensure that the network is qualified. Through a real-world case study, we demonstrate how to estimate the lower bound on reliability and how to optimize the reliability by computing the maximum deployment distance between nodes as an example. The experiments suggest that this approach is feasible.

We propose a rate-adaptive multicast (RAM) routing protocol for mobile ad-hoc networks (MANETs) that is multirate-aware. During the process of path discovery, the quality of wireless links is estimated to suggest optimal transmission rates, which are then used to calculate the total transmission time incurred by the mobile nodes on a path. Among several considered paths from a source to a destination, RAM selects the path with the lowest total transmission time. Simulation results have shown that RAM outperforms single-rate multicast in terms of packet delivery ratio, packet end-to-end delay, and throughput of the multicast group. In this paper, we apply RAM to effectively support video multicast in MANETs

Our research center has developed a cost-effective marine communication network architecture to provide affordable Internet access to marine fishermen. This solution uses a multi-level infrastructure network based on long range Wi-Fi and TDMA for backhaul. Directional antennas are used to increase the range. Standard Wi-Fi connectivity is provided on the boats to which the fishermen connect using their smartphones. The various angular and linear movements of the boat due to the oceanic waves will impact the alignment of the directional antenna to the base station thereby affecting the link quality. In this work, the extent of such movements is modeled theoretically, and the values are compared with the actual results obtained from field trials for sea states 4 and 5. It is also shown that the signal strength fluctuations are higher when the sea is rougher. Finally, future work planned for further analysis based on experimental modeling is also described.

Commercial cloud services are growing rapidly, and system architecture that can process large volumes of large-scale data for mobile devices and sensing devices is expected to emerge in the future. Mobile devices will serve as both client terminals and virtual machines in such architecture. However, end-to-end TCP sessions are affected by frequent changes in wireless link quality and movement of virtual machines in the cloud data center. In this paper, we propose a method to improve communication performance by dynamically reselecting and retuning congestion control algorithms and parameters according to changes in link quality and attributes of applications.

While the demand of video streaming services (VSSs) over the mobile networks have been soaring, the capacity of wireless links cannot keep up with the traffic needs. The difference between traffic demand and the link capacity, together with time-varying link conditions, causes inadequate service quality of video streaming, such as long buffering delays and sporadic disruptions. In this paper, by leveraging the present cloud computing technology, ESVP-Cloud architecture (i.e. Efficient Social-aware Video Prefetching) for mobile video streaming is proposed. The cloud-assisted adaptive video streaming with efficient social video sharing (ESVS) and social-aware video prefetching (SAVP) are the two basic parts of the proposed system. The personalized private agent is constructed in the cloud by ESVS and SAVP for each active mobile user to provide video streaming services efficiently. The streaming flow is adaptively adjusted by using scalable video coding technique. Similarly, ESVS monitors the social activities between each mobile user; in order that their private agents can efficiently share the videos and also try to prefetch video data segments in advance. The ESVP-Cloud architecture is proposed to demonstrate its performance, which shows that cloud computing will improve the quality of multimedia streaming and effectively offers the adaptive streaming. Moreover, this will also perform video sharing and social-aware video prefetching which reduces the access delay of shared videos to match the user demands.

The access of multimedia computing in wireless networks is concerned with the performance of handoff because of the irretrievable property of real-time data delivery. To lessen throughput degradation incurred by unnecessary handoffs or handoff latencies leading to media disruption perceived by users, this paper presents a link quality based handoff algorithm. Neural networks are used to learn the cross-layer correlation between the link quality estimator such as packet success rate and the corresponding context metric indictors, for example, the transmitting packet length, received signal strength, and signal to noise ratio. Based on a pre-processed learning of link quality profile, neural networks make essential handoff decisions efficiently with the evaluations of link quality instead of the comparisons between relative signal strength. The experiment and simulation results show that the proposed algorithm improves the user perceived qualities in a transmission scenario of VoIP applications by minimizing both the number of lost packets and unnecessary handoffs.

We investigate an amplify-and-forward (AF) full-duplex (FD) relay system, where the FD incurred self-interference (SI), through partial cancelation at relay, is treated as a useful source at destination to enhance degree of freedom in signal detection, while reducing the signal processing cost of SI cancelation. An independent component analysis (ICA) based equalization structure is employed at destination to separate and detect the desired signal from the residual SI in a semi-blind way. The mode of SI cancelation at relay is chosen adaptively based on the threshold of signal-to-interference ratio (SIR) at relay. The proposed FD relay system not only features reduced signal processing cost of SI cancelation, but also achieves much higher energy efficiency (EE) than conventional FD relay systems where SI is canceled as much as possible. Also, the proposed system enables full resource utilization via consecutive data transmission at all time and the same frequency, leading to much higher throughput and EE than the conventional time-splitting and power-splitting based SI recycling approaches that occupy partial resources. Last but not least, the proposed system demonstrates a bit error rate (BER) performance that is robust against a wide range of SI and close to the ideal case with perfect channel state information (CSI) and perfect SI cancelation, while requiring no training sequence for estimation of any channel involved.

In recent years, drones have been used in a wide range of fields, such as agriculture, transportation of goods, and security. Drones equipped with communication facilities are expected to play an active role as base stations in areas where ground base stations are unavailable, such as disaster areas. In addition, asynchronous operation is being considered for local 5G, in order to support all kinds of use cases. In asynchronous operation, cross-link interference between base stations is an issue. This paper attempts to reduce the interference caused by the drone network by introducing circularly polarized antennas against the conventional system using linearly polarized antennas. Numerical analyses are conducted to validate the effectiveness of the proposed system, where Signal-to-Interference Ratios (SIRs) are shown to be improved significantly as the numerical evaluation results. Specifically, for the scenario of only access links, in the region where conventional antenna architecture can only achieve an SIR of less than 20 dB, our proposed system applying circularly polarized antennas can almost realize an SIR of more than 40 dB. Significant improvement can be also observed in the scenario with the existence of backhaul links, where the conventional system had difficulty achieving our system design goal SIR of 16.8 dB, while the proposed antenna architecture could easily attain this goal in most regions of our evaluation ranges.