On the crest of the radio wave
It would seem that after the ratification of the 802.11n standard in the Wi-Fi industry there should be a relative lull: the specifications are approved, the certification of devices is in full swing, the corporate and home markets are saturated with hundreds of wireless devices, the offices massively say goodbye to the twisted pair and switch to already quite mature wireless technology, and all these technological joys, indissolubly, provide the Chinese workers. But the calm, of course, did not come. In the market there is a severe struggle for the hearts and wallets of IT departments.
The fact that Wi-Fi is quite ready to replace the twisted pair in most situations is understandable to all professionals working in the market. Of course, there are still people who are suspicious of Wi-Fi, because there have been many reasons for this in the past: 802.11 a / b / g was slow, WEP was easily broken, hardware was hanging, the coverage radius was not large. The list can be continued, but for today for all serious problems of "early" Wi-Fi solutions found. The last director or official who will cling to the wired network will die out, apparently, in ten years, but it is already clear that the 802.11n (and subsequent standards) equipment has won the wires. By the way, not least in this "blame" and senior officials, among whom now it's fashionable to pacing with iPads. Those who have eyes can see that they are not being telephoned with a coil to provide a secret government connection, and a quick video on the screen suggests that the packages are running over Wi-Fi, and not deadly even in the capital of 3G. The iPad will undoubtedly be followed by a wave of already normal, multi-tasking tablets that can be used for business and other reasonable purposes, and which will be added to the existing huge army of laptops, smartphones, VoIP phones and desktops.
It provides all this household with smart hardware and software, and just in the development of such hardware and software, and the main competitive struggle of leading manufacturers. The standard 802.11n is very extensive and diverse, it allows you to create very interesting engineering solutions, which for today have far from exhausted all the possibilities offered by the standard. We will specify that we are talking about solutions for the corporate market. Home Wi-Fi-infrastructure is created on the basis of fairly simple and cheap access points at a price of a couple of thousand rubles, which provide quite acceptable quality. There is even a certain number of enthusiasts who are trying to build corporate Wi-Fi networks based on such home access points (and this sometimes even works if only a couple of people sit in the office), but this is rather a marginal one.
Meanwhile, corporate solutions already today offer a lot of attractive innovations (of course, at higher prices). From the engineering point of view, these are very interesting technologies, which should be read more in detail, if you have not done so yet. And we will run through them very briefly to excite the appetite.
Cisco integrates spectrum analyzers into access points that automatically identify the source of interference, its type and switch equipment to a clear channel. So far, separate devices (ranging from a USB flash drive to a brick) have been used to analyze the spectrum with the corresponding software, which allowed the engineer to visualize a certain range of the spectrum on the computer screen and, thus, to estimate the bandwidth utilization, see interference, etc.
Cisco took a logical step forward:Spectrum Expert became part of the access point (starting with the 3500 series). The analyzer operates in both Wi-Fi bands (2.4 and 5 GHz), has a high resolution (10 kHz) and uses an intelligent system to respond to sources of interference. In addition, unlike an engineer, he works constantly. As to you such trick: if in a rest room every day at one o'clock in the day the microwave which "hammers" the channel 2, the access point will learn to be switched to the channel 11 every day at this time.
Such a compact array can change the directional pattern in real time, and the diagram is adjusted for each access point client every time when it is necessary to transfer packets to the client. Thus, the access point avoids interference and reduces the noise level for other devices and networks and increases the performance and coverage area up to three times.
Aerohive promotes fashionable clouds and Wi-Fi architecture without controllers, with centralized management of the entire infrastructure. And there are clouds here, you ask. It's very simple: the Wi-Fi network management system is now located in the cloud, which is supported by Aerohive. Those. all concerns regarding the installation and operation of the server and the software that manages the network are assumed by the hardware manufacturer. You just need to connect network access points. They themselves will find a cloud on the Internet, they will be registered and will be ready for management from the central "cloud" console, to which you can get through any browser. As for the architecture without controllers (Cooperative Control Architecture), it will allow to remove the "bottlenecks" typical for traditional Wi-Fi networks with controllers. Access points Aerohive - themselves controllers, self-organizing in the "honeycomb".
Atheros, the leading provider of access point chipsets recently purchased by Qualcomm, is starting to ship chipsets with three MIMO streams that will provide transmission speeds of up to 450 Mbps. These and many other equipment manufacturers are also actively working on transmit beamforming, a technology that allows you to "focus" the signal at the right place in space, not "spraying" it in places where there are currently no customers.
All this iron splendor will work as it should only under one condition: the network needs to be properly planned, deployed, and tested. Your and the equipment manufacturer's plans will break up into a harsh reality to smithereens if, for example, you do not take into account the fact that in a nearby office right behind a thin wall there is a 200-millimeter access point on the 6th channel with a dipole antenna that clogs all available radio -spectrum by its signal. To avoid errors, it is necessary to conduct network inspection at the stage before and after deployment.
Inspection, i.e. collection, visualization and analysis of the characteristics of the Wi-Fi network is carried out using a special software, such as TamoGraph Site Survey, which is produced by our company Tamosoft. We have two serious competitors from AirMagnet and Ekahau, and there are several simpler free programs. Further examples will be based on TamoGraph, as a more familiar and familiar program. In addition, as far as I know, only our company is actively promoting this product in Russia, has released a completely localized Russian version and accepts payment in a convenient form (Softkey, Webmoney, etc.), while AirMagnet and Ekahau are not oriented to Russia.
Having installed TamoGraph on the laptop and having preprogrammed the plan of the room or locality, the engineer goes around the room, noting his current position on the plan (or even circling the open space, say, campus, on a bicycle, while the current position can automatically mark the GPS receiver).
Having collected the data, the program can build a lot of useful visualizations, allowing to find problems that can affect the performance and coverage of the network: the signal level in the 2.4 and 5 GHz bands, the level of interference from other networks, the expected data rate, . Having documented the result using a report that is easily generated directly in the program, based on the received data, you can perform network adjustments: change frequencies, change antenna types, move, remove or add access points, and so on.
Summing up, we can say that today, having built a network on the equipment of technological leaders and analyzing it with high-quality software tools, you will get not only excellent performance and security, but also save money both at the stage of equipment purchase and at the stage of network operation. If you have not started building a Wi-Fi network, start. And, of course, do not neglect the specialized, neutral in relation to hardware and software manufacturers, training and certification, such as CWNP. Your training in Wi-Fi is the key to success.