At the wireless AP knowledge of the transmission envi- ronment conditions is provided by user nodes reporting their channel state information (CSI). Depending on the system organisation CSI feedback may take different forms includ- ing the current signal-to-noise ratio (SNR) level at the re- ceiver, the available service rates, the probability of correct transmission or any other representative value related to the channel quality .
A lot of penetration tests are conducted near or on the client’s property. With today’s mobile technology, a lot of these penetration tests include examining wireless networks. In a penetration test involving a wireless network (or any network for that matter), the first thing that must happen is the PenTest team needs to gain access to the network. It really does not matter if it is over the wireless portion of the network, or a plug in the wall. All that matters is that access is established. When access occurs over wireless, an additional risk is created – interception of sensitive data. In some cases, client wirelessaccesspoints do not use strong encryption methods to secure data transmitted to connecting clients. If a penetration test involves accessing wirelessaccesspoints, it is best if wirelessaccess is limited and used only when necessary. Once wireless network access is accomplished, the penetration testers should try and relocate that access to a wired network where additional safeguards can be implemented.
The gradual evolution of mobile communication network into 4G is increasingly making the streaming media become a new attractive business. However, the service quality of mobile streaming media is urgent to be improved for better service. The relatively fair data scheduling mechanism, node data scheduling within cell and node data scheduling when switching cells are presented in terms of mobile feature of mobile streaming media nodes. The wirelessaccess point selection for node data scheduling within cell is further researched, and a wirelessaccess point selection mechanism which is suitable for mobile streaming media is provided. The theoretic analysis verifies the fair principle of user service quality for mobile streaming media, and the appropriate data scheduling mechanism improves the reliability of data transmission, which entirely boosts the service ability of system. The simulation test shows that the wirelessaccess point selection mechanism balances the loads of wirelessaccesspoints to some extent and improves the node number of entire system.
Abstract—This paper presents the Wi-Fi phone with RFID (Radio frequency identification) of student entered the school, via WirelessAccessPoints (APs) of school will transmit MAC address with RFID of Wi-Fi phone to Internet Data Center (IDC) for server and then the message exchanged by using GSM (or 3G) has been transmitted message (or mail) to the mobile user of parents (or client user). The wirelessaccesspoints support broadcasting multiple SSIDs, each of which can have a different set of security and network setting. The RADIUS server is used to authenticate the WirelessAccess Point (AP) and mobile nodes. In safety case system, we used the several authentication and encryption options for the WLAN. We will discuss the use of Wi-Fi protected Access (WPA), RFID, IP Security (IPSec), and Secure Socket Layer (SSL), and there are high Quality of service (QoS) and performance.
provide users locations very accurately but its signals are often blocked and absorbed by walls or other obstacles at indoor scenarios. Rosums TV-GPS is an enhanced positioning technique, which works both indoor and outdoor scenarios. It uses the Time Difference of Arrival (TDOA) approach applied to TV signals to estimate the position. As said in , it needs additional hardware for television transmitter towers to achieve precise and proper time synchronization between transmitters and receivers. Another interesting localization approach is Japans Indoor Messaging System (IMES), which is an important part of the regional Quasi-Zenith Satellite System (QZSS) project. It uses GPS signals and provides precise positioning because it employs terrestrial transmitter equipments and beacons to assist the whole localization process . All the above mentioned localization systems are not suitable for proposed method, which is mentioned in this paper. The motivation is linked to three main factors: (i) the high cost of the network infrastructure for metropolitan-scale coverage; (ii) the necessity of additional modules for mobile devices, which increases implementation costs; (iii) to develop a multipurpose system which can be used as an ID card and for tracking inside campus rather than going for a smartphones for positioning system. A large number of handheld devices now have Bluetooth functionality, but it always takes a long time to read signal values, which is not practical for a mobile positioning system. Positing using RFID is another promising filed for indoor positioning, but Active RFID receivers are very expensive . Wi-Fi is a ubiquitous technology that is broadly accepted by users and they are freely available nowadays. It represents a cost efficient and reliable technique that indoor positioning services can employ. Analysis of the current signal measurement methods included, the angle of arrival (AoA), received signal strength (RSS), time of arrival (ToA) and time difference of arrival (TDoA). The techniques of AoA, ToA, TDoA require a degree of time synchronization that is difficult to achieve using inexpensive off-the shelf WLAN hardware . However, RSS indicating capable equipment is widely available in Wi-Fi devices. Utilizing existing WLAN infrastructure by reading RSS is a cost effective solution for this problem. Wi-Fi fingerprinting is a localization technique used for positioning with wirelessaccesspoints is based on measuring the intensity of the Received Signal Strength .So this paper mainly explains wifi fingerprinting technology for indoor positioning by using a hardware rather than smartphones .
The Wireless Application Protocol (WAP) is a new advanced intelligent messaging service for digital mobile phones and other mobile terminals that will allow you to see Internet content in special text format (WML Wireless version of HTML) on special WAP-enabled mobile phones. Enabling information access from handheld devices requires a deep understanding of both technical and market issues that are unique to the wireless environment. There is a constraint on the use of mobile devices or terminal in the internet due to limited CPU, memory, battery life etc. Wireless network in which it is working is constraint by limited bandwidth, high latency. WAP specification addresses these issues by the use of best of existing standards and developing new extensions when needed.
Prioritized device coexistence within CSMA based WLANs can be achieved by using different inter frame spacing (IFS) periods for different user and/or traffic classes. MAC protocol 802.11e, for instance, uses different Arbitration IFS (AIFS) periods to provide CSMA based prioritized access among different device and/or traffic classes. When a channel is found free, a node waits for a specific AIFS periods depending on the device or traffic class, before it attempts to send a packet. For higher priority primary traffic, a node waits for a smaller AIFS period. This ensures when multiple nodes contends for the channel, the primary users’ nodes (with smallest AIFS) wins. While providing reasonable access differentiation, these approaches rely only on the instantaneous channel status (i.e. free or busy) for granting access. This leads to undesirable disruptions to the PU traffic as follows. Consider a situation in which an SU intends to transmit a packet and it does so after finding the channel free (i.e. a whitespace) for the AIFS specified for the SUs. Now, in the middle of this SU’s packet transmission if a PU in the vicinity intends to send a packet, it needs to wait until the current SU transmission is over. This causes an undesirable delay for the PU traffic, which in turn will affect the PUs’ application performance. Since this is mainly a result of the SUs’ reliance only on the instantaneous channel state, a more robust approach for the SUs would be to also consider the long term whitespace model. The following DSA approaches attempt to accomplish that. Networks with primary users running 802.11 MAC protocol have recently been investigated for possible dynamic spectrum access by secondary users. The authors developed a methodology for formally analyzing the whitespace available within 802.11 primary traffic in infrastructure mode. The key idea is to model the whitespace as a semi-Markov process that relies on the underlying 802.11 state model involving DIFS, SIFS, DATA, and ACK transactions. The model describes the whitespace profile in terms of holding times of the idle and busy states of the channel. Building on this whitespace model, the authors further develop a WLAN dynamic spectrum access strategy for secondary users in which the SUs utilize packet size slots for the channel access. At the beginning of each slot, an SU senses the channel and if the channel is free then it transmits with a specified probability that is calculated from previous measurement. The objective is to minimize PU disruption and maximize SU throughput.
As a senior futurist Thomas Frey predicted in 2006, “ The world of wires has already begun its long descent into oblivion as wireless technology improves to the point where wires become obsolete” (Frey, 2006). Although fibre optics has overwhelming advantages in bandwidth and transmission loss, the cost in installation and maintenance, especially for rural areas, limit their applications in access network services . The present WLAN, IEEE 802.11 interconnections rely on wired networks to carry out bridging functions. For a number of reasons, this dependency on wired infrastructure must be eliminated because :
ARC is implemented at both the STAs and the AP. Any STA computes some measure of its urgency in transmitting packets based on its perceived QoS, like the queuing delay experienced by VoIP packets. Then informs the AP about it through some bits in the MAC header whether in data or ACK packets. We use few additional fields in the Frame Control field of the MAC header for this purpose. The AP gets the urgency feedback from the STAs, and determines which STA should claim the wireless medium sooner. Then, the AP sends a control packet (ACK) to notify all STAs about the lucky STA that will claim the channel for the next transmission period. This arbitration between the STAs by the AP reduces the competition between the STAs especially in times of congestion and avoids the 802.11 bias against the AP. This arbitration also allows for new services such as high priority 911 calls in WLANs, service guarantees for throughput demanding flows, etc. ARC does not assign access to the channel all the time, and allows for periods of CSMA/CD contention when the channel is not congested, which enhances the APs awareness about the state of flows before congestion. Simulation results reveal that ARC offers better channel utilization, better support for QoS demanding flows than the 802.11 standard.
In Wireless sensor systems (WSNs), the principle wellspring of lifetime for the center points is the battery. Speaking with various center points or detecting exercises uses an incredible measure of vitality in setting up the data and transmitting the assembled data to the sink –. As a few cases, it is undesirable to supplant the batteries that are depleting or drained of vitality. Various researchers are in this field endeavoring to find control mindful conventions for remote sensor systems, remembering the true objective to beat such vitality adequacy issues however they have their own suppositions. For the enhancement of WSN plans, scientists have proposed different methodologies . To meet distinctive plan criteria, related explores into the enhancement of remote sensor organize configuration can be assembled into three classes: 1) Optimization in the correspondence layers; 2) Node equipment streamlining and 3) Cross-layer advancement –. Be that as it may, a large portion of the improvement methods don't consider the standards, attributes and necessities of WSN which is application characterized. Hence, in proposed approach vitality streamlining is finished utilizing mixture calculations i.e. GA and BFO technique in DSR convention.
WiMAX’s strong industry backing, standards-based approach, and mobility support brought a new horizon to wireless broadband. The excellent traits and brilliant performance capability of Mobile WiMAX makes it a compelling and promising technology for high performance, low-priced broadband wireless facilities. Mobile WiMAX is on a path to deal with universal market through a common wide area broadband radio access technology and flexible network architecture. In this paper we provided an overview of Mobile WiMAX and its attributes. We addressed that mobile WiMAX can provide 10mbps of capacity per channel from each base station with a baseline configuration. The performance will enable transparency of quality of service between Mobile WiMAX and broadband wired services such as Cable and DSL, an important requirement for the success of the targeted Mobile Internet application for Mobile WiMAX. The scalable architecture, high data throughput, efficient data multiplexing and low data latency enabled Mobile WiMAX a leading solution for wireless broadband services. Hundreds of companies have contributed to the advancement of the technology and several companies have proclaimed product plans for this technology. This addresses another significant requirement for the accomplishment of the technology, which is economical in subscription services for mobile internet. The broad industry participation will ensure economies of scale that will help drive down the costs of subscription and enable the deployment of mobile internet services globally, including emerging countries.
Mobile devices are not in any way as they used to be in the past. Not only have the screens grown in size and quality but also the internal hardware has grown to reach performances levels seen only in laptop computers some years ago. As the mobile application development is luring more and more developers into the market, Android also become an attractive topic in educational environment. The growing popularity of Android have made it interesting platform now. Wireless Centralized Access for Smart Home Control is a combination of Android mobile technology and embedded system. An application should be installed on the smartphone (Android device) to control various home appliance such as lamp. User can send command using the application.
In recent few years, localization of indoor things such as pedestrian or rooms or exit doors in a building has become an exact requirement for which a variety of technologies have been introduced to obtain the good accuracy. The challenge is in developing the map based on floor plans of interiors, selecting the useful indoor positioning technology and various efficient algorithms and developing the proper indoor positioning devices for the buildings. The existing systems that deal with indoor localization services mostly use different wireless technologies like Wi-Fi, RFID Tags, Bluetooth, signals of cellular towers and ZigBee. Existing indoor localization systems can be divided into three types based on the structure of service areas. The three types of systems which can do indoor localization are 2D (two dimensional) service areas, 3D (three dimensional) service areas, and large building.
ABSTRACT: In world of wireless technology, the number of devices access the internet growing by a second most of the devices use wireless communication for access internet for sharing data between devices, this has unfortunately led to an increase in network complexity, shortage of wireless radio bandwidth and an increased risk of interference of radio frequencies put limitation on radio frequency which is used in Wi-Fi(Wireless Fidelity).That paper gives remedy on that problem, hence introducing concept of Li-Fi. Li-Fi stands for Light-Fidelity. The main principle of this technology is transmit the data using light illumination by using light-emitting diodes. In Li-Fi based system we analyzes its performance with respect to existing technology.To enjoy high data transfer rates we use of Li-Fi and also for relieving radio interference issues. Li-Fi is the future of high speed data transmission 
A multicarrier access and routing system has been proposed for use in wireless networks. Users within each cell access a radio port (RP). All RPs are connected to a radio exchange node (REN) which routes the calls or packets. The uplink access is orthogonal multicarrier code-division multiple access (MC-CDMA) and the downlink transmission is multicarrier orthogonal code-division multiplexing (MC-OCDM). The REN contains a switch module which provides continuous routes between wireless terminals without demodulation/remodulation or channel decoding/reencoding. The switch module is nonblocking and has complexity and speed linearly proportional to its size. Also, the switch module does not introduce interference into the network. Any existing interference or noise in its input port is transferred to its output port. The input-output switch connections are assigned on demand by a control unit. A random input/output port assignment process can achieve maximum switch throughput.
A hotspot is a site that offers Internet access over a wireless local area network (WLAN) through the use of a router connected to a link to an Internet service provider. Hotspots typically use Wi-Fi technology. Users can publically use wireless internet with their suitable devices. A single wireless router combining these functions may suffice. Security is a serious concern in connection with Hotspots. There are three possible attack vectors. First, there is the wireless connection between the client and the access point. This needs to be encrypted, so that the connection cannot be eavesdropped or attacked by a man- in-the-middle-attack. Second, there is the Hotspot itself. The WLAN encryption ends at the interface, then travels its network stack unencrypted and then travels over the wired connection up to the BRAS of the ISP. Third, there is the connection from the Access Point to the BRAS of the ISP. Hotspots are often found at restaurants, train stations, airports, libraries, hotels, hospitals, coffee shops, bookstores, fuel stations, department stores, supermarkets, RV parks and campgrounds, public pay phones, and other public places. Hotspot 2.0 is based on the IEEE 802.11u standard, which is a new set of protocols to enable cellular-like roaming. If the device supports 802.11u and is subscribed to a Hotspot 2.0 service it will automatically connect and roam.
Both of Apple’s notebooks fall into the midsize group at about 5 pounds, with two drives. They are priced more competitively than Apple laptops of old and include more innovations than a typical Windows notebook; Apple, for instance, was the first to include built-in antennas for wireless data networking. They’re limited to the smaller selection of software writ- ten for the Macintosh, but they are a good option for consumers who use the computer only for e-mail, Web browsing, and word processing. Apple’s less expensive iBooks start at $1300, which buys a 500-MHz processor, 15-GB hard drive, and a 12-inch screen. A unique titanium case makes the Apple PowerBook (starting at $2200) a silvery, inch-thin package that com- promises little compared with a desktop Macintosh. Packing that much muscle, however, makes the PowerBook a hot item, literally; like many notebooks, it runs too warm to hold on your knees (ouch). That helps explain why the industry prefers the term notebook to laptop.
Based on the understanding of the equilibrium and dynamics of random access games, we propose a novel medium access method derived from CSMA/CA in which each node estimates its conditional collision probability and adjusts its persistence probability or equivalently contention window accordingly. Unlike other medium ac- cess methods, our method adapts to continuous feedback signal (conditional collision probability) rather than binary contention signal (packet collision or successful trans- mission), and each node tries to keep a fixed persistence probability or equivalently contention window specified by the Nash equilibrium of random access game. In addition to simpler dynamics resulting from responding to continuous feedback and controllable performance objectives via the specification of per-node utility functions, as the conditional collision probability is a more accurate measure of contention in the network, our medium access method achieves better contention control (collision reduction) and hence higher throughput. Moreover, as wireless nodes can estimate conditional collision probabilities by observing consecutive idle slots between trans- missions, we can decouple contention control from handling failed transmissions. This also opens up other opportunities such as rate adaptation to channel variations. As a case study of medium access control design in game theory framework, we present a concrete medium access method and show that it achieves higher throughput, lower collision and better short-term fairness than the standard 802.11 DCF, and can pro- vide flexible service differentiations among wireless nodes.
With the advent of Online Public Access Catalogs, librarians and their staff have been freed from the labor-intensive processes involved in the creation and maintenance of card catalogue. At the Indian statistical Institute library, this new system has been devoted to enhancing access to the library collections. Libsys, a commercially available integrated house keeping software, is being used at ISI BC library. The experience of author in using modules of Libsys is discussed .
The selection of water points was done in two-stages, clustering of water points and stratification of water points in each cluster. In the first stage, a sampling framework of 228 water points located in nine rural wards in the Dodoma urban district was clustered into nine clusters based on the wards where the water points are located. The sampling framework for water point selection was defined in two phases, the determination of a sample size of nine wards (i.e., labelled wards in Figure 1) from 19 rural wards of the Dodoma urban district, and a random selection of such nine wards. All 228 water points located in these nine wards were extracted from an excel file titled “Water Points Locations in Rural Water Supply 2015-2016” obtained from the Government Basic Statistics Portal. This file was created and updated by the Directorate of Rural Water Supply (DRWS) on August 18, 2015, and on February 23, 2017, respectively. In the second stage, water points in each cluster were stratified into two strata, functional and non-functional water points, making a total of 18 strata for all nine clusters. Finally, water points were randomly selected from each stratum, and 23 water points were selected for all 18 strata. To account for the possibility of a household to be served by multiple water points, 47 water points were selected from 205 water points remaining after randomly selecting the 23 water points. The coverage areas of these 47 water points overlap with the coverage area of any of the 23 water points.