1- Introduction

2- Method

3- Experiment

4- Results

5- Discussion

6- Conclusion

References

Abstract

With the realization of the Internet of Things from theory to practical application, the work of ensuring high reliability of the system has become the key to system design, and it is also the obstacle to further promotion of the Internet of Things. This paper makes an in-depth study on the Internet of Things transmission and network reliability in complex environments. In this paper, we use the artificial bee colony algorithm to get the shortest path analysis of each cluster head node. The simulation results show that the algorithm proposed in this paper can effectively reduce the amount of data transmitted to sink by the sensor nodes through cluster head node fusion, improve the efficiency of data collection, energy consumption balance and network reliability, and extend the network life cycle. In addition, the index model of Internet of things reliability index system is established, and the comprehensive evaluation method of using the index is explained. The simulation results show that the proposed algorithm reduces the amount of data transmission and network energy consumption, prolongs the network life cycle, improves the efficiency of data fusion and data transmission reliability. Aodv-sms (abc-pso) routing recovery protocol shows that compared with other routing recovery strategies, packet transmission delay time is less, and the gap between them is more and more large; aiming at the end-to-end reliability and the network capacity, the paper focuses on the analysis of the impact of the change of communication link on the network capacity under the mobile node.

Introduction

In recent years, the scale of the network has expanded from one laboratory to one building to one, and there has been a strong thing. The Internet of Things system are also exposed: the working environment of the Internet of Things system is complex, and the stability of the communication link is lacking. The Internet of Things terminals are widely distributed, facing the shortcomings of terminal functions and vulnerable to attack. At this stage, it is the initial stage of the development of Internet of Things at home and abroad. The main research hotspots of many research teams focus on the following aspects: the formulation of relevant standards, the breakthrough of key technologies, and the exploration of commercial applications. Razzaque MA [1] proposed that the Internet of Things (IoT) envisions a future in which digital and physical objects or objects (eg, smartphones, televisions, cars) can be connected through appropriate information and communication technologies to achieve a range of applications. Perera C [2] surveyed more than 100 IoT smart solutions on the market and studied them carefully to determine the technologies, functions and applications used. Bertino E [3] found that based on a general description of the smart home management model of the overall framework, Stojkoska B L R [4] discusses current and future challenges of IoT-based solutions. Perera C [5] studied a variety of popular and innovative IoT solutions, using a framework built around well-known context-aware computing theory to evaluate these IoT solutions. Wang Yunan [6] realized the data recovery by using the data model of the IoT wireless sensor network with time-space correlation to perform the sparse sampling and matrix-filled approximate reconstruction techniques of the matrix composed of data samples. Xue Yuanfei [7] explored the application and design of intelligent vehicle management system for Internet of Things technology through the existing problems in the intelligent management of vehicles and the analysis of requirements.

Two prominent applications of high-accuracy time and frequency transfer can be identified: the operation of a global navigation satellite system (GNSS) and of telecommunication networks. Each of them has ambitious requirements regarding accuracy, availability, and security. Mobile telecommunication networks are operated according to the Long Term Evolution-Advanced (LTE-A) standard and are going to be prepared for future fifth generation (5G) standards. Mobile time-division duplex (TDD) operation, new features for increased spectrum efficiency like enhanced inter-cell interference cancellation (eICIC), future new mobile location-based services, and single-frequency network-based multi- and broadcast applications (MBSFN) services need not only frequency syntonization, but also time synchronization. In order to reach the required network synchronization quality [1], dedicated synchronization chains are implemented, structured as a hierarchical and layered synchronization network. Each network equipment draws its synchronization signal from a superior hierarchy element located closer to the primary synchronization source(s). An example of such a network is shown in Fig. 1. It comprises the network production part, responsible for routine operation of the network, with the requirement of continuous 24/7 operation, and a primary clock supervision part. At the network core level, the highest accuracy synchronization equipment including a number of primary reference time clock (PRTC) functions [2] is used, which is responsible for passing down the network reference time along the hierarchy. In order to increase the network synchronization stability and minimize GNSS related risks, enhanced PRTCs (ePRTCs) [3] and coherent network PRTCs (cnPRTCs) [4] combine GNSS receivers with atomic (cesium) clocks. This approach has recently been proposed for standardization by the respective committees of the International Telecommunication Union — Telecommunication Sector (ITU-T). Over a few core locations, ePRTCs are going to be distributed geographically in the network. The ITU-T specified maximum absolute time error (max|TE|) allowed for ordinary PRTC function is 100 ns [2], whereas the related value for ePRTC is more tightly set at 30 ns [3]. In addition, stability specifications for dynamic time error, expressed as maximum time interval error (MTIE) and time deviation (TDEV), apply. For 24/7 synchronization of the network production part, technologies such as synchronous Ethernet (SyncE) and Precision Time Protocol (PTP) with full timing support from the network (PTP-FTS) according to the ITU-T Recommendation G.826x series for frequency and G.827x for time synchronization, are able to ensure the required level of accuracy at the end application.

Efficient sharing of radio spectrum has been a central focus of the wireless research community for some years [9], [11], [28], [34]. Most research on spectrum sharing has followed the socalled interweave paradigm [10], under which the secondary users’ activities do not overlap with the primary users’ in time, frequency, or spatial domains. Another implicit assumption under the interweave paradigm is that there is minimal cooperation between the primary and secondary networks on both the data and control planes. Recently, there is a growing interest in exploring cooperation between primary and secondary networks. For example, in [2], [10], [13], [14], [20], [21], [25], [26], [29], [33], the authors explored the benefits of unilateral cooperation, i.e., to have secondary users help relay traffic for the primary users. To take cooperation one step further, in [31], [32], the authors advocated a bilateral cooperation between primary and secondary networks, where the two networks can help relay each other’s traffic. Such bilateral cooperation allows to pool together the resources from both networks so that users in each network can access a much richer network resources from the combined network. It was shown in [31], [32] that such bilateral cooperation brings many potential benefits and flexibilities on both the data and control planes that are otherwise not possible. Note that although the two networks are combined into one at the node level, priority or service guarantee to the primary network traffic can still be enforced by implementing appropriate traffic engineering rules.

RECENTLY, many practical problems with the uncertain feature, referred as uncertainty quantification (UQ), have received unprecedented attentions [1]. Due to the existence of uncertainty, the radar cross section (RCS) data obtained from dynamic/static measurement or electromagnetic simulation always have some mutual difference, which is even obvious sometimes. This leads to the question about the reliability of the dynamic targets’ RCS, which has also become a bottleneck in RCS research. Therefore, the uncertainty issue is not only an inevitable problem but also a valuable study topic in this field. Extensive efforts have been devoted to analyze and evaluate RCS measurement uncertainty [2], [3]. However, in the measurement process, results are often interfered by a variety of factors simultaneously, such as attitude disturbance of dynamic targets, system noise, frequency drift, environmental clutter, and so on. It is difficult to extract the impact of one of the abovementioned uncertainties from the measurement data. Therefore, there is a great necessity to study the impact of the specific uncertainty on RCS data by means of simulation. The RCS simulation of complex target is a complicated computational process which needs to take many practical factors into account, such as sheltering, multiple scattering [4], and so on. Such simulation systems are difficult to describe with all-inclusive mathematical models. Hence, the reliability of the dynamic RCS simulation has to be considered. A more feasible way of RCS UQ is the sampling-based statistical methods. Monte Carlo (MC) method is considered to be one of the most popular UQ methods [5], [6]. Its simplicity and nonintrusive characters simplify the implementation by repeating uncertain experiments and sample statistics with sufficient amounts. Although the convergence efficiency of such method is relatively low, it is widely used in the analysis of various complex electromagnetic problems because of its strong adaptability and less constraint on conditions. These advantages of MC method make it a good choice in UQ study, since it is a classical samplingbased statistical approach, the comparison and evaluation of numerical simulation data are critical for UQ.

مقاله سال 2016

در WSN، نود ها اطلاعات را از محیط اطراف دریافت میکنند و به ایستگاه اصلی انتقال می دهند. انتقال داده های متعدد در شبکه ی گیرنده ی بی سیم باعث می شود که نود های نزدیک به ایستگاه اصلی ازدحام پیدا کنند. در اینجا هدف ما این است که یک تکنیک را برای اجتناب از ازدحام و کاهش آن توسعه دهیم. به این منظور، ما مسیرها را براساس فاصله ی بین فرستنده و گیرنده، مقدار موفقیت نسبی(RSR) نود و اشغال بافر یکنود انتخاب میکنیم. بر اساس این سه پارامتر، یک تابع مطلوبیت معرفی میکنیم که برای هریک از نود های انتقال دهنده ی مجاور استفاده می شود. از این رو نود انتقال دهنده از میان نود های مجاور نود دارای بالاترین U-value را به عنوان نود هاپ بعدی خود انتخاب میکند. بنابراین ما با نتخاب نود های غیر متراکم به عنوان نود هاپ بعدی از ازدحام اجتناب میکنیم و سپس بر اساس مقدار RSR ازدحام را کاهش میدهیم.

مقاله سال 2016

International Conference on Advanced Technologies for Communications

این مقاله، مسئله طراحی اکتساب اولیه برای تقسیم مولتی پلکس ها با استفاده از کد WALSH-HADAMARD(WHCDM) را مورد بررسی قرار می دهد. برخلاف کدهای مجازی نویزی مورد استفاده در ارتباطات پراکندگی طیف ها، کد WALSH-HADAMARD در توابع همبستگی خودکار به شدت مورد استفاده قرار می گیرد. طراحی اکتساب اولیه برای ارتباطات پراکندگی طیف با توالی مستقیم نمی تواند برای WHCDM مورد استفاده قرار گیرد. برای حل این مسئله، ما طرح اکتساب اولیه WHCDM را با روشی نوین پیشنهاد می دهیم. این روش نماد زمان بندی را بر مبنای کد تابع همبستگی خودکار WALSH و واریانس انرژی سیگنال را بعد از دی مولتی پلکسینگ کشف می کند. نتایج شبیه سازی کامپیوتری تایید کردند که این طرح دارای اکتساب سریعی می باشد.

مقاله سال 2016

شبکه‌روی تراشه (NoC) با قابلیت پیکربندی مجدد امکان دور انداختن پورت‌های خراب یک سوئیچ معیوب به جای غیرفعال کردن کامل آن را فراهم می‌سازد؛ بنابراین پیکربندی مجدد دانه‌ریز شبکه مقدور می شود و ساختارهای NoC را تنومند‌تر می‌کند.

این مقاله به ارائه‌ی یک رویکرد عیب‌یابی عملیاتی می‌پردازد که اطلاعات خطای ساختاری را از تست‌های عملیاتی استخراج کرده و از این اطلاعات برای شناسایی توابع/پورت‌های خراب یک سوئیچ معیوب استفاده می‌کند. بخش‌های خراب کنار گذاشته می‌شوند درحالیکه توابع باقی‌مانده برای عملکرد معمول مورد استفاده قرار می‌گیرند. این روش مستقل از معماری سوئیچ و توپولوژی NoC بوده و می‌توند برای هر نوع خطای ساختاری اعمال شود. تفکیک‌پذیری عیب‌یابی تست عملیاتی بسیار بالاست به‌گونه‌ای که تقریبا برای 64 درصد خطاها در سوئیچ فقط یک پورت باید خاموش شود. با عملیاتی ماندن بقیه‌ی بخش‌ها، تأثیر خطاها بر توان‌عملیاتی و عملکرد به کمترین مقدار می‌رسد.

ما کدهای قطبی را برای هدف خاص طرح‌های (روش‌های) درخواست خودکار ترکیبی تکرار با افزونگی افزایشی (IR-HARQ) ایجاد می‌کنیم. نرخ تطبیق روش پیشنهادی توسط puncturing و توسعه کد تضمین می‌شود. الگوریتم جدید puncturing برای کدهای قطبی پیشنهاد داده‌شده است و ما الگوریتمی را برای یافتن دنباله‌های (رشته‌های) توسعه‌دهنده خوب برای کدهای قطبی از طریق نرخ اختیاری puncture شده باهدف بهبود گذردهی تا اندازه ممکن توسعه می‌دهیم. نتایج شبیه‌سازی برای انواع مختلف الگوریتم‌های puncturing و توسعه ارائه‌شده است. ما نشان می‌دهیم که چگونه الگوریتم توسعه پیشنهادی درزمانی که به‌خوبی با الگوریتم puncturing مناسب کار کند و نرخ puncturing به‌خوبی انتخاب شود، منجر به روش‌های کدگذاری IR-HARQ می‌شود که می‌توانند در توان 1 دسی‌بل ظرفیت شانون در طیف بسیار وسیعی از نسبت‌های سیگنال به نویز کار کنند.