Networks without wires
Using modern inexpensive means it is possible easily and to construct fast the multi-user computer networks supporting wireless data transfer
Modern business is not thought any more without usage of various computers. They became the irreplaceable arrangements which have received a wide circulation in all spheres of human activity. They are applied successfully not only large, but by small corporations. However, despite permanently growing computing power, single arrangements are not always capable to solve tasks facing to them effectively. To expand functionality of computers it is possible at the expense of their multiplexing in a network. It provides an effective utilisation of corporate computing resources, and at the expense of an output in the Internet and access to users to world informational databanks. Besides, local and wide-area networks have given possibilities of the beam coupling which efficiency, as is known, is a lot of above traditional couriers and mail. It is necessary to add, that implantation of informational-communication processing techniques allows to raise speed of information interchange sharply. And it, as is known, facilitates acceptance of fast and effective solutions that can be solving in the conditions of hard competitive struggle. This circumstance in many respects promoted fast distribution of various electronic resources and processing techniques, including mail and the Internet, access to which carry out by means of numerous computers and computer networks.
Estimating possibilities of such resources, usually mean table models. However the powerful stationary arrangements entangled by numerous cables of power supplies and link, quite often limit freedom of the users. At the same time industrial necessity and modern high rate of a life demands also mobility high level. For this reason compact, transportable computers step-by-step win liking of corporate and private users.
Expanding possibilities of such computers, rather recently experts of corporation of Intel the complex solution which has received the name of Intel Centrino was offered. Not pressing in technical details, it is necessary to mark, that one of its components is the special unit realising processing technique of wireless data transfer in a radio band, known as Wi-Fi. In computers such unit is presented by appropriate hardware-software resources.
The built in resources of wireless access Wi-Fi support high-speed data transfer in allowed band of presence of special arrangements — so-called points of "hot" access — Hot Spot, collective radio stations playing a role. Here it is necessary to mark, that now exists three standards of wireless data transfer in a radio band: IEEE 802.11a, IEEE 802.11b, IEEE 802.11g. The first of them is not licensed yet and consequently in Russia is not resolved, the second and the third have transited all relying negotiations. They also represent today interest for potential users.
It is necessary to mark, that the wireless computer communication in a radio band of frequency of 2,4 GHz provides for standard IEEE 802.11b a transfer rate of the information to 11 Mbit/with, and newer IEEE 802.11g — to 56 Mbit/with. It is necessary to add, that networks of more high-speed variant support correct operation and before the released arrangements calculated on IEEE 802.11b, the truth, on speeds inherent in them — to 11 Mbit/with.
Certainly, the resulted values are far that provide modern gigabajtnye resources of wire networks. However it is important, that Wi-Fi does not demand for the organisation of computer networks the organisation of wire interconnections, that, certainly, conveniently. As to usage Wi-Fi for the output organisation in the Internet 56 Mbit/with is at all a little. Really, usual phone lines, provide, as a rule, speed to 56 Kbit/with. It means, that 56 Mbit/with enough for 1000 users working with traditional speed 56 Kbit/with. In a case of ownership of the channel the user can accept and send files in 1000 times faster, that is in case of rather volume files demanding earlier for transmission or reception of a business hour, now enough three with small seconds.
It is necessary to mark, that steady link Wi-Fi of standards «b» and «g» is accessible usually on a distance in some tens metres. On open space it can reach 100 metres and even more, that is a distance for many cases quite sufficient. Nevertheless, it is necessary to mark, that in process of increase in distance from point Hot Spot to the computer supplied with resources Wi-Fi, and in that specific case it there can be corresponding a notebook or a handheld computer, the transfer rate of computer data decreases. So, for example, on the brink of operation area, that is in several tens metres from point Hot Spot, speed decreases desjatikratno.
Definitive range and information transfer rate depends on conditions of distribution of radio-waves. Really, on open space in the absence of obstacles and reflexions, and also crosstalks, speed and range is more, and for example, in the brick house at passing of radio signals through its walls — it is less. In this case limiting range can make some tens metres. But even more modestly results in case of multiple passing of signals through ferro-concrete walls look. However and with Wi-Fi computer experts quite often find the optimal solutions providing comprehensible results of operation of a multiterminal wireless network in the last, least favorable variant of maintenance of arrangements.
By means of resources of wireless data transfer it is possible to carry out link between computers, using shared resources of system, including shared access in the Internet and global e-mail. This access is provided through one of stationary computers of the wireless network Wi-Fi, hooked up to appropriate high-speed communication circuits of the provider of a wide-area network.
Taking into account the specified possibilities it is possible to assert, that thanks to resources Wi-Fi the last obstacle limiting a freedom of movement for users of transportable computers disappears. Now, being in an operative range of resources of reception/information transfer, it is possible to use beam coupling arrangements, not resorting to the help of the wires limiting freedom of moving of computers, representing terminals of a wireless network. Moreover, in the long term at a continuous (nonseparable) coating of locales limitation on movement of users of transportable arrangements during reception and sending of computer data acts in film. It is linked by that processing technique Wi-Fi supports practically continuous information transfer at change of points Hot Spot without disrupture of link and information loss. Certainly, it is possible only at the appropriate organisation of structure of wireless networks and their firmware supporting functioning of resources Wi-Fi up to the mark.
Considering possibilities and perspectives of the given perspective processing technique, it is necessary to mark, that in case of stationary usage of arrangements of a wireless communication the task of fast expansion of a computer network easily enough dares. First of all, it is caused by that the problem linked to work on laying of high-frequency cable lines disappears. Especially it is convenient to those corporations which rent industrial premises on short period. It is necessary to mark, that for the corporations allocated in large cities with durable history which Moscow and St.-Petersburg, the solutions providing absence of necessity of performance of cable operations concern, for example, in some cases possess essential advantage. It is linked by that many buildings are architecture monuments and consequently possible building operations are strictly regulated. In such cases wireless computer networks are practically uncontested solutions for effective operation of the numerous corporations allocated in such buildings, whose functioning depends on computers and communication facilities.
However, recognising advantages of wireless processing techniques, it is necessary to remind once again, that except the transportable structure transportable or desktop computers of special resources, stationary points of access Hot Spot are required. Estimating their parametres and possibility of usage it is necessary to mark, that recently the given steels are cheaper and more accessible. It is linked by that a number of known manufacturers have developed a wide spectrum of rather inexpensive arrangements of the wireless communication, providing to users necessary grade of service. So, for example, some of these corporations have released special packages of the motherboards supplied with necessary hardware-software resources Wi-Fi. These resources provide functions Hot Spot and allow to develop fast the local area network of wireless transmission of the computer information protected by special hardware-software resources for small office. Usually, these resources are presented by the special card inserted into the special plug of the motherboard. One of such cards is resulted on the Photo 1.
Photo 1. An example of card Wi-Fi with the on-line aerial
As alternative, there are variants with built in structure of motherboards special resources. Such solution differs the smaller price and bolshej dependability of operation. On the Photo 2 one of such motherboards is resulted.
Photo 2. An example of the motherboard with built in resources Wi-Fi
One more possibility of fast expansion of wireless networks is usage of the special routers which are fulfilling functions of points Hot Spot and hooked up to selected computers by means of standard ports USB.
Considering resources of fast and rather inexpensive construction of networks Wi-Fi, it is necessary to mark, that wireless networks cannot be considered as panacea from all problems. When possibilities Wi-Fi are unavailable or for any reasons cannot be used, standard resources of a faxmodem and commuted phone lines to the aid come. However according to experts in the nearest some years thanks to successes of wireless processing techniques the situation radically will vary and existing necessity of traditional communication facilities will lose the sharpness. As resources Wi-Fi all become more accessible and cheaper.
As to applied possibilities of the wireless access provided built in in transportable and stationary computers with resources Wi-Fi it is really convenient functional mode. Certainly, it is fairly exclusive in case of a finding in allowed band of operation of appropriate resources of data transfer/reception.
It is necessary to remind, that small dimensions and weight of transportable computers which concern, by the way, not only notebooks, but also a handheld computer, allow to work not only in the fixed place, for example, only behind a desk. As a result transportable arrangements allow to raise labour productivity without considerable physical, mental and an emotional pressure.
In the same cases when there is a stationary system, by means of usage of the additional rather inexpensive specialised resources described above, it is possible to develop the multifunctional network Wi-Fi constructed by a hierarchical principle. It will provide wireless access to resources of the given system by means of a notebook with built in Wi-Fi unit or integrated into structure of a handheld computer radio controllers, or the desktop stationary PC which structure includes appropriate specialised resources. Thus by means of the specified arrangements it is possible to get access to resources of network computers, and at hooking up of one of stationary computers to the Internet network — to resources of a wide-area network and to world e-mail. And all it becomes possible in a mode of wireless access. By the way, effective operation with the resources enumerated above is possible even outside of not only rooms, but even buildings. Thus operation can be organised in an adjacent building or even, for example, in adjacent park.
It is necessary to add, that network Wi-Fi can be protected from unauthorized access by special software of enciphering and access differentiation.
As to value judgment of results of durable usage of wireless networks arrangements with Wi-Fi really in most cases allow to refuse a permanent job behind desktop systems, giving wireless access to their resources. However would be not correct to oppose computers of different groups. Each of these groups possesses the specific set of functional parametres and consumer properties that does their effective in appropriate segments of the computer market.
Parsing perspectivity described above resources of wireless information transfer Wi-Fi, it is necessary to add, that wide functionality of the given processing techniques already on advantage was estimated by numerous users. The fast increase in number of wireless networks and appropriate resources of wireless data transfer testifies to it. Step-by-step becomes obvious, that the wireless communication is any more a tribute to a transiting fashion, and the following evolutionary stage of development of processing techniques and resources of telecommunications.
However would be an error to consider, that wireless processing techniques in the course of the development completely will supersede the traditional solutions providing presence of cable systems, providing copper and fiber-optical lines. Both directions of development of communications — both cable, and wireless processing techniques possess the unique advantages. As a result they will develop and in the course of the implantation will occupy appropriate segments of the computer market, supplementing each other and promoting convenience and overall performance rise.
Article is published in log Business the Class.