Introduction
Wireless communication has improved dramatically in the last few years. Their networks are indispensable providing the means for mobility, city-wide Internet connectivity, distributed sensing and outdoor computing [10]. It allows the transfer of messages between people that are on the other side of the world. Without wireless communications people would not have a lot of the devices many 21st century citizens could not live without, namely the smartphone. It is also required for devices using Bluetooth, remote controls, Wi-Fi; really any electrical devices that communicate via a wireless or wired channel [1]. The popularity of communication systems is seen from nearly anywhere in cellular networks, wireless local area networks
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Today there are more than 7 billion mobile phone subscriptions, an increase of about 97% since the turn of the millennia whilst there are 3.2 billion people that currently use the internet. However, in the least developed countries only 89 out of the 940 million use the internet. This is only a 9.5% penetration rate which when compared to a developed country which average at a penetration rate of 82.2% seems quite ludicrous [2]. Almost 60% of the Internet traffic is generated by peer-to-peer applications where, typically, large files, such as movies and software distributions, need to be distributed from one or very few servers to a large number of users [1]. These statistics inform us just how important the work in the field of wireless communications is. Work will continue so that the less fortunate have more of a chance to get access to things like cellular networks and the internet. This will put pressure on maintaining the excellence of wireless communications in terms of rate, spectral efficiency and power consumption. An attempt is made also to keep the data transmission system as fast and reliable as possible. All of this has motivated researchers to integrate various wireless platforms such as cellular networks, WLANS and also, MANETs which is a mobile ad hoc network which continuously is a self-configuring, infrastructure-less …show more content…
These are amplify-and-forward, decode-and-forward and compress-and-forward.
The amplify-and-forward (AF) is the most simple and quickest of the three. It acts as an analogue repeater and was introduced in 2004. Whenever this type of relaying receives a signal all that it does is amplify the received signal from the source and transmit it to the destination. The destination receives two independently faded versions of the information so that it is able to make better decisions. Obviously errors will occur using this strategy. No encoding or decoding takes place here and the noise gained by the signal from the source to the relay will also be amplified!
The decode-and-forward (DF, may also be described as digital regenerative repeaters) strategy decodes the message received at the relay. It performs very well here but when it does fail to decode properly, an error propagation phenomenon is observed. To counter this methods have been introduced where the relay detects and forwards the source information only is case of high instantaneous source-to-relay link signal-to-noise
wireless communication got a lot of attention when a message was transmitted that allowed for
Wireless is a methodical account of the early development of wireless telegraphy and the inventors who made it possible. Sungook Hong examines several early significant inventions, including Hertzian waves and optics, the galvanometer, transatlantic signaling, Marconi's secret-box, Fleming's air-blast key and double transformation system, Lodge's syntonic transmitter and receiver, the Edison effect, the thermionic valve, and the audion and continuous wave. Wireless fills the gap created by Hugh Aitken, who described at length the early development of wireless communication, but who did not attempt "to probe the substance and context of scientific and engineering practice in the early years of wireless" (p. x). Sungook Hong seeks to fill this gap by offering an exhaustive analysis of the theoretical and experimental engineering and scientific practices of the early days of wireless; by examining the borderland between science and technology; depicting the transformation of scientific effects into technological artifacts; and showing how the race for scientific and engineering accomplishment fuels the politic of the corporate institution. While the author succeeds in fulfilling these goals, the thesis, it seems, is to affirm Guglielmo Marconi's place in history as the father of wireless telegraphy.
The first component I will be discussing is SIGINT. Some positives are that is can be done from afar, it can be conducted with out a target knowing, and it is straight from the source. An example of be done from afar is when the aerial platform Guardrail is sent up to conduct aerial collection and the operator is miles away on a base and the collector
8) Ian F. Akyildiz, Ismail H. Kasimoglu, “Ad Hoc Networks’’, Wireless sensor and actor networks: Research Challenges, Georgia Institute of Technology, USA, May-2004.
The uses of Digital Signal Processing in communications has become so large scale that nearly any form of analog communication is considered obsolete. Today, nearly any form of communication used, aside from verbal communication, relates to Digital Signal Processing. Some of the more prominent uses for DSP in communications are; local area networks, cell pho...
Print. The. Gordon A. Gow, and Richard K. Smith. Mobile and wireless communications: an introduction, McGraw-Hill International, 2006. Print.
technologies such as Bluetooth and ZigBee which are used to carry the information from perception devices to a nearby gateway based on the capabilities of the communicating parties. Internet technologies such as WiFi, 2G, 3G, and 4G carry the information over long distances based on the application. Since applications aim to create smart homes, smart cities, power system monitoring etc.
Wi-Fi (Wireless Network) or 802.11 networking is a phenomenal way of providing Internet wirelessly at a low cost. Using radio waves, a wireless network connects a PC, mobile phone or just about anything that connects to the internet wirelessly by a router. By transmitting signals at 2.4 or 5 GHz it allows the waves to transmit more data at a faster rate. Typical Wi-Fi standards are 802.11a, b, g, n, or ac and they can switch up the frequency depending on the model (Brain). Families can create their own wireless network that can be shared between family members without the use of hooking all their devices up to the modem and can also protect their home network from potential hackers with the use of a TKIP or AES encryption. Businesses can also create a “hotspot” which is an area that has wireless networks for free or at a set fee. This is extremely convenient for commuters that need internet access while they are at work, waiting on a plane, or just sitting at a coffee spot without the need for wires(Cox).
Wireless is everywhere today whether at home working from your WIFI network to work where you might be linked a wireless network or even through your phone through a 3G or 4G network to connecting to an open wireless networks. As you can see for the most part people are connecting to wireless from the moment they leave their home till they get to work and then back. While wireless comm...
A multiplexer is a form of transmission in which allows multiple signals to travel simultaneously over one medium. The signals are carried into smaller channels called subchannels. There are many types of multiplexing, for example, time division multiplexing, statistical multiplexing, and etc. The types that are used depends on what the media, transmission, and reception devices can handle. A multiplexer transmits at the end of a channel and demultiplexers are at the receiving end separating the combined signals and restores them to their original form. Multiplexing also comes in hand with networking to increase the data that is sent and shared over a given time span on a given bandwidth.
Introduction: This is a 21th century, technology is the most important and improved thing of the human life. It makes life easier and faster. Development of faster sophisticated technology we have better and fast life. So all we are connect each other by computer network. There are two different way of network: Wired and wireless. Now day we can found network almost everywhere. Home, business, public place, Airport, Planes, hospitals, school, train everywhere we can found networking. Therefore, almost every sector of the economy that has affected by wired and wireless technology. Wired network and wireless protect both has security, But in general wireless network is less secure than wired networks. For proper security AP (access point) and its antenna should be right position. Also add a wireless access point or use a wireless router we can connect to network wirelessly. AS we using more and more of devices (smart phones, tablet and computers) rely on wireless networking, we have to improve our network security too.
When electronic devices transfer information to another electronic device, the devices need to know when data flow is beginning and ending. This is done with signals for synchronization.i
b) Information cannot be shared at a wider range to different receivers at distanced locations
In a client-server network, the capability of the server will decline as the amount of clients asking for services from the server increment. In spite of that, in P2P systems overall network performance really enhances as an increasing number of nodes are added to the system. These companions can arrange themselves into a specific purpose groups(ad hoc) as they impart, work together and offer data transfer capacity with another to finish the current workload (sharing of files). Each companion can transfer and download at the meantime, and in a procedure like this, new companions can join the group while old companions leave at whatever time. This active re-association of group peer members is not opaque to ultimate consumer.
People in the present society have turned from the use of the old means of communication to the more advanced and technological ways of communicating. Technology has made it easier for people to communicate in a faster, efficient, and cost saving means through the introduction of the communication channels. The world has turned out to be the centre for technology with different technologies emerging daily as the people continue to develop from time to time to cope with the growing technology. The benefits of adopting the communication technology are explained in this article which shows why people do not function without technology.