Kot posledica nadgradnje tradicionalnih standardov 802.11 mora naprava, ki podpira Wi-Fi Direct protokol, delovanje omogoˇ cati v dveh razliˇ cnih vlogah. Omogoˇ cati mora delovanje v vlogi vstopne toˇ cke (angl. access point - AP ) in v vlogi odjemalca. Oba naˇ cina delovanja sta bila podprta ˇ ze pri starejˇsih standardih. Novost Wi-Fi Direct protokola je, da sta ti vlogi doloˇ ceni di- namiˇ cno in da lahko naprava teoretiˇ cno opravlja naloge obeh vlog hkrati. Iz Slike 3.1 je razvidno, da protokol Wi-Fi Direct temelji na standardih 802.11. Naprave v okviru standarda Wi-Fi Direct komunicirajo znotraj vzposta- vljene P2P skupine (angl. P2P Group), ki ponuja enake funkcionalnosti kot tradicionalno Wi-Fi omreˇ zje z vstopno toˇ cko. Vzpostavitev skupine si bomo podrobneje pogledali v razdelku 3.3. Naprava, ki v tako vzpostavljeni skupini opravlja naloge vstopne toˇ cke se imenuje P2P Group Owner (P2P GO), medtem ko naprave v vlogi odjemalca imenujemo P2P Clients. Kot ˇ ze omenjeno sta vlogi dodeljeni dinamiˇ cno, zato morajo naprave po postopku odkrivanja za vzpostavitev P2P skupine najprej doseˇ ci dogovor o opravljanju vloge P2P GO. Ko je vloga P2P GO dodeljena, je skupina vzpostavljena in odjemalci se lahko pridruˇ zijo skupini tako kot pri tradicionalnih omreˇ zjih z vstopno toˇ cko. Naprave, ki delujejo kot odjemalci, lahko s P2P GO komuni- cirajo samo v primeru, da podpirajo ustrezen 802.11 standard in zahtevane varnostne mehanizme. Naprave, ki tem pogojem ne zadostujejo, vidijo na- pravo P2P GO kot navadno vstopno toˇ cko in ne delujejo v okvirju protokola Wi-Fi Direct.
Abstracts. The former design of VoiceCommunication System (VCS) has many problems, such as backward technology, single-architecture system and detachment between design and operation. In order to solve these problems, this article is going to introduce a solution called standardization design of VCS. This standardization not only absorbs industry advanced communication system technology, but also effectively integrates them and field operation and maintenance experience. Therefore, with this standardization design, system could better adapt to the requirements of technical development and links up with new technology and new application in the future. Besides, it also realizes the designing goal of achieving “Four Capacities” including Strategic Business Supporting Capacity, Integrating Management Capacity of VCS, The Capacity of Rapid Deployment and The Capacity of Innovative Application of VoiceCommunication. More importantly, this standardization design improves the uniformity of the Group’s multiple-plants voice systems; effectively reduce the cost of design and construction.
Cell phones are ubiquitous today - millions of wireless consumers making billions of calls each year in the United States alone. Service providers are facing a huge growth of networks accompanied with the unfair demographic distribution that can be concentrated one day in one place and another day in a different place. A large number of callers suddenly appear during a big event in convention centers, conferences, libraries, and football stadiums. Cell phone service providers are overwhelmed with such hotspots and many calls are dropped. These calls are likely to be in close proximity and are usually short in duration. We propose a solution to relieve the infrastructure from this sudden congestion by allowing cell phone users to communicate directly using a peer-to-peer network. Cell phones handle connection establishment, routing, and maintaining the conversation with minimal infrastructure use. As a result, cell phone users can make phone calls free of any charge. Moreover, calls consume less power by using peer-to-peer communication. Our experimental results using the network simulator ns-2 as well as our prototype implementation demonstrate the utility of our technique.
The implementation of a WiFiDirect network in NS3 is a non-trivial task because NS3 does not pro- vide any support to group formation, the capability of Group Owner and client, and other features of WiFiDirecttechnology. Thus coding everything from the scratch will be time consuming. Moreover, we need to implement the individual field level simulation of the PHY packets which requires a complete system level implementation of all blocks in the transmitter and receiver, especially the new features of 802.11ac. NS3 does not provide any well-known libraries which can help in achieving our aims. Most of algorithms in the thesis have been developed from a complete system levels point of view i.e., transmitter, communication channel, and receiver. We have used six profile channel models (TGn Channel A-F), which are not sup- ported by NS3. On the other hand, all these tasks can be achieved in Matlab because Matlab is very flexible and provides helpful documentation. In addition, the availability of WLAN, communication system, and signal processing toolboxes helps in the overall system level implementation. Moreover, we have developed the system in incremental fashion which is easily applicable in Matlab and not in NS3. Initially, the MAC layer was implemented using the DCF in Matlab and later on the PHY layer and six channel profiles were built on the top of it.
We next analyze the CDF of the (mid- dle subplot), i.e., the time required to negotiate roles (if needed), to establish a secure communication and to provide the IP configuration. It should be first noted that, for the case of the Autonomous group formation, the open source implementation we are using  triggers an additional scan right before the WPS phase, something not specified in the standard. This scan increased the delay by approximately three seconds, thus we decided to remove its effect to present a clear overview of the Wi-Fi Direct performance. The figure shows that the three group formations present similar behavior, with the differences over simulations being caused by channel interference and the generation of cryptographic information, and that the simplified signaling of the Persistent case reduces delays in about half a second. It should also be noted that despite the fact that the Autonomous frame exchange is simpler than the Standard one, in practice they result in almost the same delay. This is because the GO Negotiation phase takes very little time as compared to the WPS provisioning phase, which requires a long frame exchange that is affected by the interference from other WLANs.
Dept of Computer Science & Engineering Ballarpur Institute of Technology, Bamni, Ballarpur, India Abstract- In this project, our main aim is to provide a free way access to communicationusing the power of Android smart phones. In this modern world, everyone wants a leisure lifestyle. Nowadays, every phone has embedded communication technologies like Wi-Fi. Wi-Fi provide many rich features like faster transmission, better communications. So in this world full of connectedness, we are providing an android application which lets user communicate free of cost usingWiFi-Direct. Wi-Fi direct is new technology defined by the Wi-Fi alliance to enhance direct device to device communication without the need of a wireless access point. Our application runs on Android operating system and we’ve chosen Android because nowadays most of smart phones runs on Android platform.
This paper presents the design and implementation of “Computer Interfaced Voice activated switch” using speech recognition technology. Computer (PC) based electrical appliances control is useful for industrial applications, home automation, and supervisory control applications. This project gives exact concept of interfacing high voltage electrical devices to a computer system. The project involves speech activation or deactivation of electrical load usingvoice command or manual method. This is achieved by developing a speech application using visual basic 6.0 and then linking it to a program that drives the parallel port of the computer. Two stages were implemented in the design of this system; the hardware and software design stages. All stages were carried out carefully, adhering strictly to the design specifications. This proved useful as the results obtained after construction and testing were extremely satisfactory because the system was able to switch the connected loads ON and OFF usingvoice command and manual control method. This is a secure and reliable system which can be used in homes, industries, churches, offices, etc. The system involves the AT89C52 microcontroller, Max232 (IC), actuators (relays), and other active and passive electronic components connected together to form the hardware unit. The AT89C52 microcontroller was used to store all the machine codes of the system. The computer was used to establish an interface or a communication link with the microcontroller. The communication link used in this project was the parallel port. The computer sends the corresponding signal to the microcontroller anytime a voice instruction/manual command is received, then the microcontroller executes the instruction by switching ON/OFF the corresponding load connected to it through the actuator. Satisfactory results based on the design specification were achieved after construction.
utilize Distribution Network Protocol (DNP3) over TCP/IP for inter-device communica- tion. The DNP3 protocol itself works in a layered manner and there is a lot of processing involved at its own transport and data link layer. Detailed operation of each layer in the DNP3 protocol stack can be found in . Because of this processing delay, the overall latency of the application is directly affected. Therefore, the memory of the em- bedded computer (RAM), the CPU speed, and the operation system platform are very important parameters to choose hardware device confirguration. The cost of designing the communication network increases if you keep upgrading the hardware specifications of the power and network devices used. This in turn decreases the end to end latency of the application. Hence it is an important decision to establish a reasonable balance between the delay incurred due to the hardware limitations of the CPU and the applica- tion latency. In our work, we have modeled the intelligent electronic device specifications, their related processing delays and communication capabilities using a setup and results obtained from a real-world implementation study mentioned in .
key requirement, such as access control and point-of-sale. A blend of serial communications interfaces ranging from a USB 2.0 Full Speed device, multiple UARTS, SPI, SSP to I2Cs and on-chip SRAM of 8 kB up to 40 kB, make these devices very well suited for communication gateways and protocol converters, soft modems, voice recognition and low end imaging, providing both large buffer size and high processing power. Various 32-bit timers, single or dual 10-bit ADC(s), 10-bit DAC, PWM channels and 45 fast GPIO lines with up to nine edge or level sensitive external interrupt pins make these microcontrollers particularly suitable for industrial control and medical systems.
Lossless communication system with a network stream, requiring two devices that are used to transmit data, in this case is My-RIO and PC. The data is sent in the form of voice data from the microphone contained in My-RIO input. Input data is received by a single voice on the network stream write blocks on My-RIO. Before single write transmit the voice data in the single read PC, reader to initialize the block create endpoints on each endpoint network stream. Initialization was done by the size of the buffer, ID sender/recipient and sender address/recipient data. After initialization is complete, the data is sent from a single write My-RIO towards single read PC using Wi-Fi communications. To perform the test latency, data received on the PC need to be sent back to My-RIO to determine the round trip time two-way communication. The process is done by sending the received data direct read single write on a single PC to the network stream PC. Then the data is sent using Wi-Fi communication to the single read contained in my-RIO. Once the data is received single read My-RIO, destroy blocks endpoint will remove all endpoints contained in My-RIO or PC.
Hypothesis Four: Climate Effects Controlling for Prior MIS Variables The fourth hypothesis, climate factors will have a positive correlation with implementation outcomes controlling for the effects of contextual and individual-level variables was tested with cross-level operator analysis (Klein et al., 2000). Cross-level operator analysis (CLOP) is a statistical technique designed to test the effect of higher-level variables or “operators” (in this research, departmental climates) on lower-level outcome data individual-level (Use, Perceived Impact on Educational Outcome, and Satisfaction) using stepwise multiple regression techniques. While there are a growing number of statistical techniques able to evaluate factors operating at different levels of analysis, CLOP was chosen for its ability to test the direct effect of multiple cross operators. Moreover, CLOP and hierarchical linear modeling (or “HLM,” an alternative to CLOP) have been demonstrated to yield very similar parameter estimates (Klein et al., 2000). While CLOP and HLM differ in interpretation of how variance in predictor variables is assigned to outcome variables 1 , the two techniques will provide the same substantive conclusions.
Such convergence will have significant implications for existing regulatory frameworks based on relatively rigid definitions of services and networks. Such service classification issues are already occurring with the deployment of VoIP services and are likely to become more complex with new converged services. As an example, in early 2004, in Korea, there were discussions as to whether WiBro, a new high-speed mobile Internet service, is a mobile service, in which case only mobile network operators should have the right to provide WiBro service, or whether fixed network operators need to establish a separate enterprise to provide WiBro. Some regarded WiBro as a reinforced model of wireless Internet used by cell phones, and others argued that it is an extended model of broadband Internet so fixed network operators should have the right to provide this service. The Ministry of Information and Communication (MIC) decided to allow both fixed and wireless network operators to provide this service on the basis that it is a combination of wire and wireless technology. Regulators or policy makers elsewhere are likely to have to cope with these kinds of issues when considering service and network convergence enabled by WiFi and mobile roaming, VoWiFi or fixed-mobile convergence. In that regulatory policy has increasingly emphasised technology neutrality and places emphasis on benefits to consumers and the creation of effective competition, it is unlikely that there should be any significant regulatory obstacles to these new developments.
In the past, the goal of telecom engineers is to provide better services at any cost. The costs were being imposed on a customer. To this end, only the rich could afford these services.There have been changes to this situation over the years. The industry is driving to the positive direction where better services are being provided at very low cost to customers. In addition, telecom companies have experienced a significant increase in number, which has led to a high level of competition among them. At the same time, the number of customers has also grown tremendously. Thus, there is need for better management of resources such as optimization of the quality of the services. Trade-offs need to be made between costs, quality, and priorities. There are currently systems like Skype, Gtalk, which are useful for low cost communication. For using these services we need to have access to net connection. It could be a costly affair for small companies. Installation and maintenance of wired LAN is long and costly affair. Comparatively installation of WLAN is simple and quicker. Maintenance required is also less. It is also easier to troubleshoot. Hence we propose a wireless system for audio and video calls.The motive behind system is to enable the cost effective voice and video communication. We have designed a client server model based system to implement it. Also there is no need for internet connection for working of this system.Communication has been of prime importance to man since past. Various methods have been make use of communication. In early days of voice transfer PSTN networks were used. These consisted of Private Branch Exchange office owned by service providers.
The wireless LAN based on Wi-Fi technology has been widely used in the room and the services. In addition, it is not limited to information communication. Many applications such as human detection, indoor localization, through wall tomography, activity recognition, are emerging in the field of wireless local area network applications. In the indoor environment, transmitted wireless signals do not usually reach the receiver along a direct path. In fact, the received signal is usually the superposition of signals from the furniture, human body, and other obstacles, and is diffracted and scattered. This phenomenon is known as the multipath effect. Physical space limits the spread of radio signals. In contrast, the wireless signals can also be used to sense the physical environment in which they pass. Whether it is an environmental object (such as a wall, furniture) or a human body, its location and movement can modulate the wireless signal. Thus a periodic signal or variable signal is formed. Based on the signal analysis, it can infer perception of the environment.
Abstract — This paper presents the designed and implementation of spread spectrum technology for data transfer to overcome the interference problems associated with narrow band, very high frequency and ultra high frequency data transfer systems. The spread spectrum communication is used to reduce jamming of communication and provides a heightened secure communication. In this paper, the design and analyzes are implemented by Field Programmable Gate Array (FPGA) for baseband spread spectrum communication system using Pseudo Noise Sequences (PNS) for spreading digital data. The sequence generator and direct sequence spread spectrum (DSSS) for a single user is implemented in a FPGA module. The generated pseudo noise sequences are investigated for autocorrelation, cross correlation and balance properties. The bit error rates performance of the system is evaluated in multiuser environment under AWGN and reveals that, the DSSS system using pseudo noise sequences as spreading sequences significantly outperforms for the conventional PN sequences system Keywords— Bit Error Rates (BER), Field Programmable Gate Array (FPGA), Direct Sequence Spread Spectrum (DSSS), Pseudo Noise (PN) and Spread Spectrum (SS).
Wi-Fi, also spelled Wifi or WiFi, is a popular technology that allows an electronic device to exchange data or connect to the internet wirelessly using UHF radio waves. The name is a trademark name, and was stated to be a play on the audiophile term Hi-Fi. The Wi-Fi Alliance defines Wi-Fi as any "wireless local area network (WLAN) products that are based on the Institute of Electrical and Electronics Engineers' (IEEE) 802.11 standards". However, since most modern WLANs are based on these standards, the term "Wi-Fi" is used in general English as a synonym for "WLAN". Only Wi-Fi products that complete Wi-Fi Alliance interoperability certification testing successfully may use the "Wi-Fi CERTIFIED" trademark.
The ideas claimed by different authors support and reinforce the vein of targets in this study that ICT influences the educational trends. The implementation of 2002 Revised Basic Education Curriculum (RBEC) of Philippine government recognize ICT as paramount of alleviating poverty and achieving competitive advantage in the global economic ground. Its salient features is the inclusion of basic learning competencies in computer skills both elementary and secondary education (Camacho and Pintor, 2015). The implementation of ICT integration brought challenges to schools‟ management for it created issues to the administrators, teachers, and students. Particularly, in the District of Lanuza, Division of Surigao del Sur, four secondary schools works collaboratively,
Dictated short range(1000) communication (DSRC) for Intelligent Transportation System (ITS) has opened the door to hundred of projects and applications of vehicle to vehicle communication around the world. In 1991 the US federal communication commission reserved licensed bandwidth of 75 MHz spectrum around 5.9 GHz that allows information to be exchanged among vehicles regardless of their brand. This spectrum will provide very high rates with low latency and high security in matter of supporting this wireless communication between vehicles, set of standards were needed to ensure that vehicles understand each other , for example ,IEEE 802.11p-2010 standards of wireless link for V2V communication and IEEE P1609.x/D5.8 protocol for information across the wireless link.
As we can see in the table 1 WiFi has the highest range for communication. But also it has the highest transmission power. On the other hand Bluetooth and ZigBee both have less transmission power as compared to WiFi. The comparison shows that only ZigBee can match the range of WiFi since bluetooth range is only 10 m. Also WiFi and ZigBee work on the same frequency band which helps operating them in same device.
For each central control unit, there are 64 connections, the same number as in previous intercom systems, but with only half the volume and with only half the number of wires. All connected devices work without any blocking whatsoever. The CPU card includes a serial interface that can communicate with a COM interface on a laptop computer. This allows maintenance work to be performed on the equipment using a computer program, and even remote maintenance is possible.