Showing papers in "Int'l J. of Communications, Network and System Sciences in 2014"

Fire-Detectors Review and Design of an Automated, Quick Responsive Fire-Alarm System Based on SMS

Abstract: In this work a review of existing fire-detector types has been carried out along with the development of a low cost, portable, and reliable microcontroller based automated fire alarm system for remotely alerting any fire incidents in household or industrial premises. The aim of the system designed is to alert the distant property-owner efficiently and quickly by sending short message (SMS) via GSM network. A Linear integrated temperature sensor detects temperature beyond preset value whereas semiconductor type sensor detects presence of smoke or gas from fire hazards. The sensor units are connected via common data line to ATMega8L AVR microcontroller. A SIM300CZ GSM kit based network module, capable of operating in standard GSM bands, has been used to send alert messages. The system is implemented on printed circuit board (PCB) and tested under different experimental conditions to evaluate its performances.

Security Approaches in IEEE 802.11 MANET —Performance Evaluation of USM and RAS

Abstract: Evaluation of IEEE 802.11 Mobile Ad Hoc Networks (MANET) security issues becomes significant concern for researchers since Denial of Service (DoS) attacks are recognized as one of the most harmful threats. A variety of security mechanisms are proposed to solve security dilemma in MANETs against different layers of DoS attacks. Physical Layer jamming attacks exhaust the victim’s network resources such as bandwidth, computing power, battery, etc. Unified Security Mechanism (USM) and Rate Adaptation Scheme (RAS) are two of the proposed methods by researchers against DoS attacks. USM and RAS mechanisms are simulated through OPNET simulator and Jamming Attack is generated on the network for each security mechanisms to compare specific performance metrics on the network.

Compression of ECG Signals Based on DWT and Exploiting the Correlation between ECG Signal Samples

Abstract: This paper presents a hybrid technique for the compression of ECG signals based on DWT and exploiting the correlation between signal samples. It incorporates Discrete Wavelet Transform (DWT), Differential Pulse Code Modulation (DPCM), and run-length coding techniques for the compression of different parts of the signal; where lossless compression is adopted in clinically relevant parts and lossy compression is used in those parts that are not clinically relevant. The proposed compression algorithm begins by segmenting the ECG signal into its main components (P-waves, QRS-complexes, T-waves, U-waves and the isoelectric waves). The resulting waves are grouped into Region of Interest (RoI) and Non Region of Interest (NonRoI) parts. Consequently, lossless and lossy compression schemes are applied to the RoI and NonRoI parts respectively. Ideally we would like to compress the signal losslessly, but in many applications this is not an option. Thus, given a fixed bit budget, it makes sense to spend more bits to represent those parts of the signal that belong to a specific RoI and, thus, reconstruct them with higher fidelity, while allowing other parts to suffer larger distortion. For this purpose, the correlation between the successive samples of the RoI part is utilized by adopting DPCM approach. However the NonRoI part is compressed using DWT, thresholding and coding techniques. The wavelet transformation is used for concentrating the signal energy into a small number of transform coefficients. Compression is then achieved by selecting a subset of the most relevant coefficients which afterwards are efficiently coded. Illustrative examples are given to demonstrate thresholding based on energy packing efficiency strategy, coding of DWT coefficients and data packetizing. The performance of the proposed algorithm is tested in terms of the compression ratio and the PRD distortion metrics for the compression of 10 seconds of data extracted from records 100 and 117 of MIT-BIH database. The obtained results revealed that the proposed technique possesses higher compression ratios and lower PRD compared to the other wavelet transformation techniques. The principal advantages of the proposed approach are: 1) the deployment of different compression schemes to compress different ECG parts to reduce the correlation between consecutive signal samples; and 2) getting high compression ratios with acceptable reconstruction signal quality compared to the recently published results.

QoE Assessment of Will Transmission Using Vision and Haptics in Networked Virtual Environment

Abstract: In this paper, we handle collaborative work in which two users move an object together to eliminate a target in a 3-D virtual space. In the work, the users transmit their wills about movement direction of the object to each other by only haptics and by haptics and vision (including with/ without drawing an arrow to indicate the direction of force applied to the object by the other user). We carry out QoE (Quality of Experience) assessment subjectively and objectively to investigate the influence of network delay on will transmission. As a result, we clarify the effects of vision on the transmissibility of haptic will transmission.

Cloud Security: Services, Risks, and a Case Study on Amazon Cloud Services

Abstract: Recent advances have witnessed the success and popularity of cloud computing, which represents a new business model and computing paradigm. The feature of on-demand provisioning of computational, storage, and bandwidth resources has driven modern businesses into cloud services. The cloud is considered cutting edge technology and it is solely relied on by many large technology, business, and media companies such as Netflix or Salesforce.com. However, in addition to the benefit at hand, security issues have been a long-term concern for cloud computing and are the main barriers of the widespread use of cloud computing. In this paper, we briefly describe some basic security concerns that are of particular interest to cloud technology. We investigate some of the basic cloud concepts and discuss cloud security issues. Amazon Web Services is used as a case study for discussing common cloud terminology. Data security, as well as some cloud specific attacks is introduced. The current state and the future progression of cloud computing is discussed.

Design of a Microcontroller-Based Data Acquisition System for Ground Weather Observations: Evaluation of Radio Refractivity of Air

Abstract: A meteorological data acquisition system is built using a PIC16F877A microcontroller and electric output-based sensors This system is programmed in C language using the PCWH compiler It is smart, accurate, cheap, small, light and easily movable It is designed to automatically get instantaneous measurements of air temperature, atmospheric pressure, and relative humidity Depending on their utilisation, these measurements are collected with repetition rate tuneable from one minute to one hour They are displayed on LCD screen and transferred to a personal computer where they are stored and processed As an application, such data are recorded in situ and used to estimate the radio refractivity of air near the ground in real time This parameter is necessary to account for the propagation of radiofrequency waves through the lower atmosphere, during wireless transmissions

Application of Machine-Learning Based Prediction Techniques in Wireless Networks

Abstract: Wireless networks are key enablers of ubiquitous communication. With the evolution of networking technologies and the need for these to inter-operate and dynamically adapt to user requirements, intelligent networks are the need of the hour. Use of machine learning techniques allows these networks to adapt to changing environments and enables them to make decisions while continuing to learn about their environment. In this paper, we survey the various problems of wireless networks that have been solved using machine-learning based prediction techniques and identify additional problems to which prediction can be applied. We also look at the gaps in the research done in this area till date.

Accident Prevention and Reporting System Using GSM (SIM 900D) and GPS (NMEA 0183)

Abstract: The Rapid growth of technology has made our life easier. This advancement in technology also increased the traffic hazards. Hence the ratio of road accidents which take place frequently increases causing immense loss of life due to poor emergency facilities. Main causes behind these road accidents include: lack of training institutes, unskilled drivers, poor road conditions, use of cell phone during driving, over loading and poor governmental plans in this regard. Our research provides a solution for accident detection and prevention for human life safety. It enables intelligent detection of an accident at any place and reports about the accident on predefined numbers. Our system consists of two parts, alarming part and messaging part. The hardware includes SONAR ranging modules, vibration sensor, three modules GPS receiver (NMEA), Microcontroller (AT89S51), GSM modem (SIM 900D) and an Alarm. When distance is too short between the vehicle and obstacle then alarm will be “ON” as an indicator to move vehicle in other direction which is safer but when a vehicle faces accident despite of alarm, immediately vibration sensor will detect the signal and then Microcontroller sends the alert message through the GSM modem including the location to predefined numbers that can be reserved for a rescue team. Our designed system has been tested at different locations and found to be effectively working by sending alert messages to mobile phone user.

Performance Study of Mobile TV over Mobile WiMAX Considering Different Modulation and Coding Techniques

Abstract: With the advent of the wide-spread use of smart phones, video streaming over mobile wireless networks has suddenly taken a huge surge in recent years. Considering its enormous potential, mobile WiMAX is emerging as a viable technology for mobile TV which is expected to become of key importance in the future of mobile industry. In this paper, a simulation performance study of Mobile TV over mobile WiMAX is conducted with different types of adaptive modulation and coding taking into account key system and environment parameters which include the variation in the speed of the mobile, path-loss, scheduling service classes with the fixed type of modulations. Our simulation has been conducted using OPNET simulation. Simulation results show that dynamic adaptation of modulation and coding schemes based on channel conditions can offer considerably more enhanced QoS and at the same time reduce the overall bandwidth of the system.

Network Coding and Quality of Service for Mobile Ad Hoc Networks

Abstract: Network Coding is a relatively new forwarding paradigm where intermediate nodes perform a store, code, and forward operation on incoming packets. Traditional forwarding approaches, which employed a store and forward operation, have not been able to approach the limit of the max-flow min-cut throughput wherein sources transmitting information over bottleneck links have to compete for access to these links. With Network Coding, multiple sources are now able to transmit packets over bottleneck links simultaneously, achieving the max-flow min-cut through-put and increasing network capacity. While the majority of the contemporary literature has focused on the performance of Network Coding from a capacity perspective, the aim of this research has taken a new direction focusing on two Quality of Service metrics, e.g., Packet Delivery Ratio (PDR) and Latency, in conjunction with Network Coding protocols in Mobile Ad Hoc Networks (MANETs). Simulations are performed on static and mobile environments to determine a Quality of Service baseline comparison between Network Coding protocols and traditional ad hoc routing protocols. The results show that the Random Linear Network Coding protocol has the lowest Latency and Dynamic Source Routing protocol has the highest PDR in the static scenarios, and show that the Random Linear Network Coding protocol has the best cumulative performance for both PDR and Latency in the mobile scenarios.

Technical Possibilities of Cloud-Based Virtual Reality Implementing Software as a Service for Online Collaboration in Urban Planning

Abstract: In this paper we discuss the technical possibilities of cloud-based virtual reality (cloud-based VR) computing tools for online collaboration in urban planning and design. We first create a digital asset representing our design proposal of a pedestrian bridge in Shibuya, Tokyo. A platform for cloud-based VR technology, i.e., a VR-Cloud server, is used to open the VR dataset to public collaboration over the Internet. The digital asset representing the design scheme of our pedestrian bridge includes buildings, roads, trees and street furniture for the entire urban area. The vehicles and people are designed and inputted into the virtual world of the urban area, in which they run and walk with predefined behaviour scenarios. Users share the VR world by accessing the VR-Cloud servers from remote clients, using cloud communication software to review vehicle and pedestrian crowd simulations and discuss the design concepts. Meanwhile, we compare the advantages and disadvantages of three cloud-based VR tools on their technical support for net collaboration: 1) VR-Cloud; 2) Google Earth; and 3) 3DVIA.

A Simplified Improvement on the Design of QO-STBC Based on Hadamard Matrices

Abstract: In this paper, a simplified approach for implementing QO-STBC is proposed and evaluated with improved performance. It is based on the Hadamard matrix, in which the scheme exploits the Hadamard matrix property to attain full diversity. Hadamard matrix has the characteristic that diagonalizes a quasi-cyclic matrix and consequently, a decoding matrix so that a diagonal matrix which permits linear decoding is achieved. Using quasicyclic matrices in designing QO-STBC systems requires that the codes should be rotated to reasonably separate one code from another such that error floor in the design can be minimized. It will be shown that, orthogonalizing the secondary codes and then imposing the Hadamard criteria of the scheme can be well diagonalized. The results of this simplified approach demonstrate full diversity and better performance than the interference-free QO-STBC. Results show about 4 dB gain with respect to the interference-free QO-STBC scheme and it performs alike with the earlier Hadamard based QO-STBC designed with rotation. These results achieve the consequent mathematical proposition of the Hadamard matrix and its property is also shown in this study.

Fast Handover Pre-Authentication Protocol in 3GPP-WLAN Heterogeneous Mobile Networks

Abstract: The demand of ubiquitous communications drives the development of advanced mobile technologies. Meanwhile, recent increases in mobile data usage and the emergence of new IP service applications constitute the motivation to integrate 3GPP cellular mobile systems with broadband WLANs. Since 3GPP and WLAN systems complement each other in terms of infrastructure and network coverage and bandwidth, 3GPP-WLAN Heterogeneous Mobile Networks based on the 3GPP-based Home Network (3GHN) are proposed for meeting the growing demands in high-speed data access on any mobile devices. However, heterogeneous radio access technologies and architectures lead to many interworking issues, such as network transparency, security mechanism, seamless handover, and quality of service. Among of them, security and handover are the major motives to ensure the confidentiality, reliability and continuity of services in 3GPP-WLAN Heterogeneous Mobile Networks. This paper proposes fast handover pre-authentication protocol to reduce the handover authentication latency and authentication signaling overhead during the whole handover session. The proposed protocol supports Intra-Domain Handover Pre-Authentication (Intra-HO Pre-Auth) and Inter-Domain Handover Pre-Authentication (Inter-HO Pre-Auth) for preauthenticating the Mobile User (MS) prior to performing an Inter-domain Handover (Inter-domain HO)/Intra-domain Handover (Intra-domain HO) process. Meanwhile, the reduction in retrieving new Authentication Vector sand key sets from the Home Location Register/Home Subscriber Service/Authentication Center in 3GHN achieves for minimized redundant authentication signaling transactions between 3GPP domains and WLAN domains. In addition, this paper provides simulation results which show that the proposed Intra-HO Pre-Auth achieves 49% handover authentication performance improvement compared to EAP-AKA, and the proposed Inter-HO Pre-Auth achieves 26% handover authentication performance improvement as well.

On One Model of Multichannel Queuing System with Unreliable Repairable Servers and Input Memory

Abstract: The work deals with the development of analytical model of multichannel technical queuing system with unreliable servers and input memory where server failure flows and incoming request flows comply with Poissonian laws, while the flows of failed facilities repairs and flows of incoming requests comply with exponential laws of probability distribution. Random process of system change-over is a Markovian process with continuous time and discrete states. Relations binding basic parameters and output characteristics of the system indicated are obtained as probabilities of system staying in the given moment in one of the possible states. The proposed model is the most generalized compared to some models known in literature which could be considered as special cases of the considered model.

Improved Alamouti STBC Multi-Antenna System Using Hadamard Matrices

Abstract: To achieve multiple input multiple output (MIMO) in wireless communication, the orthogonal space-time block coding (OSTBC) is evaluated next. At first, the OSTBC design is extended to include Hadamard matrix, referred to in this work, as traditional Hadamard OSTBC. Next, the Hadamard matrix is imposed on the conventional OSTBC, which is referred to, in this work as, Alamouti-Hadamard STBC. Both the traditional Hadamard OSTBC and the conventional STBC are compared with the Alamouti-Hadamard STBC. It will be shown that imposing the Hadamard conditions over the conventional OSTBC, the performance of the OSTBC 2-transmit antenna scheme can be significantly improved in terms of BER performance. All propositions are well supported with analytical derivations.

Laboratory Test Bench for Research Network and Cloud Computing

Abstract: At present moment, there is a great interest in development of information systems operating in cloud infrastructures. Generally, many of tasks remain unresolved such as tasks of optimization of large databases in a hybrid cloud infrastructure, quality of service (QoS) at different levels of cloud services, dynamic control of distribution of cloud resources in application systems and many others. Research and development of new solutions can be limited in case of using emulators or international commercial cloud services, due to the closed architecture and limited opportunities for experimentation. Article provides answers to questions on the establishment of a pilot cloud practically “at home” with the ability to adjust the width of the emulation channel and delays in data transmission. It also describes architecture and configuration of the experimental setup. The proposed modular structure can be expanded by available computing power.

A Fast Heuristic Algorithm for Minimizing Congestion in the MPLS Networks

Abstract: In the multiple protocol label-switched (MPLS) networks, the commodities are transmitted by the label-switched paths (LSPs). For the sake of reducing the total cost and strengthening the central management, the MPLS networks restrict the number of paths that a commodity can use, for maintaining the quality of service (QoS) of the users, the demand of each commodity must be satisfied. Under the above conditions, some links in the network may be too much loaded, affecting the performance of the whole network drastically. For this problem, in [1], we proposed two mathematical models to describe it and a heuristic algorithm which quickly finds transmitting paths for each commodity are also presented. In this paper, we propose a new heuristic algorithm which finds a feasible path set for each commodity, and then select some paths from the path set through a mixed integer linear programming to transmit the demand of each commodity. This strategy reduces the scale of the original problem to a large extent. We test 50 instances and the results show the effectiveness of the new heuristic algorithm.

Multi-Cultural Dynamics on Social Networks under External Random Perturbations

Abstract: This work deals with the development of multi-cultural network-centric dynamic models under the influence of personal intra- and inter-members, as well as community. Each individual member of a society is influenced by her/his interactions with fellow members of the family, neighborhood, region and the universe. The behavior of such complex and highly interacting social networks is characterized by stochastic interconnected dynamical systems. The primary goal is on laying down an investigation of both qualitative and quantitative properties of this network dynamical system. In particular, we would like to determine the regions of conflicts and coexietence as well as to establish the cohesion and stability of emerging states. This is achieved by employing the method of system of differential inequalities and comparison theorems in the context of the energy function. The developed energy function method provides estimates for regions of conflict and cooperation. Moreover, the method also provides sufficient conditions for the community cohesion and stability in a systematic way.

Analysis of Rate One Quasi-Orthogonal Space-Time Block Coding over Rayleigh Fading Channel

Abstract: Full-rate is very important in any data transmission coding. For transmitting data at low bit rate than full-rate code, higher modulation scheme is required. But it is impossible to design full rate orthogonal designs with complex constellation for more than two transmit antennas. Only Alamouti code provides full-rate for two transmit antennas. In this paper, Bit Error Rate (BER) is calculated for Quasi-Orthogonal Space-time Block Coding (QOSTBC). Here we work with Rayleigh fading channel. We consider the codes which decodes pairs of symbols instead of simple separate decoding like Orthogonal Space-Time Block Coding. In Quasi-Orthogonal Space-time Block Code full-rate is achieved but full-diversity is sacrificed. Diversity is the most important techniques for providing reliable communication over fading channels. One of the diversity techniques that uses multiple transmit and/or receive antennas is space diversity. Multiple antenna technique provides a space diversity to struggle with the fading without necessarily sacrificing bandwidth resources, so the excellent solutions of removing the fading of the channel for broadband wireless communications is using space diversity. Then, with the constellation rotation of the symbol, rotated version of Quasi-Orthogonal Space-Time Block Code is generated. It provides full diversity. We simulate BER for QOSTBC, rotated QOSTBC, orthogonal STBC and for uncoded system. The simulation result shows that QOSTBC and rotated QOSTBC perform better than other systems. It shows that QOSTBC provides a full transmission rate but that rotated QOSTBC provides the full rate with the full diversity.

Sensing the Nation: Smart Grid’s Risks and Vulnerabilities

Abstract: This paper presents issues and trepidations associated with transferring from conventional methods of electricity monitoring and distribution to the cyberspace, especially in developing countries like Nigeria where current approaches have failed to provide regular, reliable electric power. The Smart Power Grid is a developing concept already put to test, successfully, in very advanced countries. The implementation of the Smart Grid will include the deployment of many new technologies and multiple communication infrastructures. Connecting the electricity grid to the Internet can provide a lot of advantages in terms of control, data viewing and generation. However, in Nigeria, the proposal to transfer conventional methods to the Smart Grid has perhaps not hit the deck yet because of excessive focus on power generation, and because of the annotated reservations associated with the Internet, as the Smart Grid involves circulation and dispersal via inter-networking structures. This paper describes the key technologies that support Power Grid substation automation, summarizes the mode of implementation into the existing Nigerian electrical infrastructure and brings fore issues and mitigating approaches to provide a seamless and securitised transfer of the current power grid to the Smart Grid.

Image Encryption Scheme Based on Filter Bank and Lifting

Abstract: In this paper, the quality of image encryption using filter bank with lifting scheme has been studied and evaluated. Many extensive techniques have been applied to examine the security of the image encryption using the filter bank cipher with one or two rounds. To analyze and evaluate the proposed scheme, many parameters have been employed, such as, histogram analysis, correlation coefficient, global entropy, block entropy, avalanche effect, number of pixel change rate (NPCR), unified average change intensity (UACI), compression friendliness, exhaustive key analysis, and key sensitivity test. The simulation results showed that, the quality of the image encryption passes all these tests. Moreover, it reaches or excels the current state-of-the-arts. So that, the proposed image encryption process produces random-like output from the statistical point of views.

Playing against Hedge

Abstract: Hedge has been proposed as an adaptive scheme, which guides the player’s hand in a multi-armed bandit full information game Applications of this game exist in network path selection, load distribution, and network interdiction We perform a worst case analysis of the Hedge algorithm by using an adversary, who will consistently select penalties so as to maximize the player’s loss, assuming that the adversary’s penalty budget is limited We further explore the performance of binary penalties, and we prove that the optimum binary strategy for the adversary is to make greedy decisions

Performance Evaluation of Spectrum Detection in Cognitive Radio Network

Abstract: In mobility management, detection of spectrum hole plays very important role for doing spectrum handoff mechanism. Operation of the cognitive radio depends on the spectrum sensing which is the most important task in case of cognitive radio network. Detection of spectrum holes (underutilized sub-bands of the radio spectrum) estimates average power, throughput and utilized time for each spectrum hole. But in case of reactive spectrum handoff mechanism, spectrum handoff delay becomes tedious task. So in order to make spectrum handoff mechanism efficient our scheme proposed spectrum handoff mechanism with negligible spectrum handoff delay. In this paper we had real time experimental setup with the spectrum handoff mechanism. We investigate algorithm for spectrum handoff mechanism which strongly minimizes spectrum handoff delay of cognitive radio network using spectrum detection method for sensing spectrum holes.

Creation of Virtual Wi-Fi Access Point and Secured Wi-Fi Pairing, through NFC

Abstract: The growing ubiquity of Wi-Fi networks combined with the integration of low-cost Wi-Fi chipsets in all devices makes Wi-Fi as the wireless technology the most used for accessing to internet [1]. This means that the development of a Wi-Fi strategy has become an imperative for almost all operators worldwide. In this context, APs (Access Points) have to become as secure as cellular networks. Furthermore, authentication process between a mobile device and an access point has to be automated, without user constraining configuration. For reaching this purpose, client must have different credentials depending on authentication method. Our goal is to create an architecture that is both ergonomic and flexible in order to meet the need for connection and client mobility. We use NFC technology as a radio channel for starting communication with the network. The communication initiation will instantiate a virtual Wi-Fi AP and distribute all policies and access certificates for an authentication based on EAP-TLS (it could be extended to any EAP method for 802.1X standard). The end result of our new topology is to allow access to services through a virtual Wi-Fi AP with an enterprise-grade in a public hotspot.

An X-Band Low Noise Amplifier Design for Marine Navigation Radars

Abstract: In this paper, the design of a 9.1 GHz Low Noise Amplifier (LNA) of a RADAR receiver that is used in the Navy is presented. For the design of the LNA, we used GaAs Field-Effect Transistors (FETs) from Agilent ADS component library. In order to keep the cost of the circuit in low prices and the performance high, we design a two-stage LNA.

Unsupervised Neural Network Approach to Frame Analysis of Conventional Buildings

Abstract: In this paper, an Artificial Neural Network (ANN) model is used for the analysis of any type of conventional building frame under an arbitrary loading in terms of the rotational end moments of its members. This is achieved by training the network. The frame will deform so that all joints will rotate an angle. At the same time, a relative lateral sway will be produced at the rth floor level, assuming that the effects of axial lengths of the bars of the structure are not altered. The issue of choosing an appropriate neural network structure and providing structural parameters to that network for training purposes is addressed by using an unsupervised algorithm. The model’s parameters, as well as the rotational variables, are investigated in order to get the most accurate results. The model is then evaluated by using the iteration method of frame analysis developed by Dr. G. Kani. In general, the new approach delivers better results compared to several commonly used methods of structural analysis.

On One Model of Complex Technical Queuing System with Unreliable Devices and with Time Redundancy

Abstract: The given article deals with the development of analytical model of request service process by multichannel technical system with unreliable, repaired and reconfigured service facilities. It is assumed that the system is functioning in service mode of random length random request flows. The system considers the existence of time redundancy for afterservice of calls, the service of which is interrupted with refusal, non-depreciating the performed part of the task. Special probability functions are introduced which on the basis of probability reasoning allow to make the systems of integral equations describing the dynamics of request service process.

The COMMStellation TM Satellite Constellation for Broadband Communication System Model in NS-2

Abstract: This paper presents the evaluation performance of a hybrid satellite constellation network which provides internet access based Transport Control Protocol (TCP). The evaluated satellite network uses the constellation topology operating on Low Earth Orbit (LEO). The COMMStellationTM satellite system implemented using network simulator 2 (NS-2). In this paper, we modified a congestion window control based on TCP Westwood. The results show that the proposed technique reduces end-to-end (E2E) delay of transmitting packets. Hence the number of retransmission packets reduced.

Modeling and Simulation Study of Space Data Link Protocol

Abstract: This research paper describes the design and implementation of the Consultative Committee for Space Data Systems (CCSDS) standards REF _Ref401069962 \r \h \* MERGEFORMAT [1] for Space Data Link Layer Protocol (SDLP). The primer focus is the telecommand (TC) part of the standard. The implementation of the standard was in the form of DLL functions using C++ programming language. The second objective of this paper was to use the DLL functions with OMNeT++ simulating environment to create a simulator in order to analyze the mean end-to-end Packet Delay, maximum achievable application layer throughput for a given fixed link capacity and normalized protocol overhead, defined as the total number of bytes transmitted on the link in a given period of time (e.g. per second) divided by the number of bytes of application data received at the application layer model data sink. In addition, the DLL was also integrated with Ground Support Equipment Operating System (GSEOS), a software system for space instruments and small spacecrafts especially suited for low budget missions. The SDLP is designed for rapid test system design and high flexibility for changing telemetry and command requirements. GSEOS can be seamlessly moved from EM/FM development (bench testing) to flight operations. It features the Python programming language as a configuration/scripting tool and can easily be extended to accommodate custom hardware interfaces. This paper also shows the results of the simulations and its analysis.

Bandwidth Constrained Priority-Based Routing Algorithm for Mobile Ad Hoc Networks

Abstract: A Mobile Ad hoc NETwork (MANET) is a dynamically formed self-configured network by an autonomous system of mobile nodes connected by wireless links. With the advancements of wireless technology, the necessity of Quality of Service (QoS) is increasing rapidly. Developing QoS constraint routing protocol for MANETs is still a challenging task. As the nodes are free to move randomly, most routing protocols for MANETs are susceptible to node mobility. As routing protocol has to decide which route is able to fulfill the requirement of the desired QoS, routing is the most important part to accomplish the specified application with desired QoS metrics. This paper is based on design of such a kind of proposed MANET algorithm that will estimate the available bandwidth throughout the path by assigning priority. Based on available bandwidth, packets are transferred from source to destination of the applications in queue based on priority. The proposed algorithm is implemented and simulated using NS-2 simulator. Results of our approach show that new protocol can significantly reduce overheads and decrease overall end-to-end delay.