Wi-Fi Network Planning and Maintenance

    Tamograph

    On the crest of a 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, device certification is in full swing, the corporate and home markets are saturated with hundreds of wireless devices, offices in droves say goodbye to twisted pair and switch to already quite mature wireless technology, and all these technological joys are tirelessly provided by Chinese workers. But the lull, of course, did not come. There is a fierce battle on the market for the hearts and wallets of IT departments.

    The fact that Wi-Fi is quite ready to replace twisted pair in most situations is clear to all professionals working in the market. Of course, there are still people who are suspicious of Wi-Fi, because there were many reasons for this in the past: 802.11 a / b / g was slow, WEP broke easily, the hardware hung, the coverage radius was small. The list can be continued, but today for all serious problems of the “early” Wi-Fi solutions are found. The last director or official who will cling to the wired network will probably die out in ten years, but it is now clear that the 802.11n equipment (and subsequent standards) defeated the wires. By the way, not least the highest officials are “to blame” for this, among which it has now become fashionable to walk around with iPads. Those who have eyes, let them see that they are not followed by a signalman with a coil to ensure secret government communications, and a smart video on the screen suggests that the packets are running on Wi-Fi, and not on the dead even in the 3G capital. The iPads, without a doubt, will 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 already huge army of laptops, smartphones, VoIP phones and desktops.

    The whole enterprise is provided with smart hardware and software communications, and it is precisely in the field of developing such hardware and software that the main competition between leading manufacturers is taking place. The 802.11n standard is very extensive and diverse, it allows you to create very interesting engineering solutions that today have not yet exhausted all the possibilities offered by the standard. We make a reservation 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 are even a 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 are sitting in the office), but this is rather a marginal trend.

    Meanwhile, corporate solutions today offer a lot of attractive innovations (of course, at higher prices). From an engineering point of view, these are very interesting technologies that you should read more about if you haven’t done so yet. And we will run through them very briefly to arouse appetite.

    Cisco integrates spectrum analyzers into access points that automatically determine the source of interference, its type and switch equipment to a channel that is clean from interference. So far, for the analysis of the spectrum, separate devices have been used (the size starting from a flash drive up to a brick) with the corresponding software, which allowed the engineer to visualize a certain range of the spectrum on a computer screen and, thus, evaluate the load of the range, see interference, etc.

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    Cisco has taken a logical step forward: the Spectrum Expert analyzer has become part of the access point (starting with the 3500 series). The analyzer operates in both Wi-Fi ranges (2.4 and 5 GHz), has a high resolution (10 kHz) and uses an intelligent system for responding to interference sources. In addition, unlike an engineer, he works constantly. How do you like this trick: if in the restroom every day at one o’clock a microwave is turned on, which “clogs” channel 2, then the access point will learn to switch to channel 11 every day at this time.

    Ruckus lures with its smart and compact arrays of BeamFlex antennas , providing unprecedented range and quality coverage.

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    Such a compact array can change the radiation pattern in real time, and the diagram adjusts to each client of the access point each time it is necessary to transfer packets to the client. Thus, the access point avoids interference and reduces noise levels for other devices and networks and increases productivity and coverage area up to three times.

    Aerohivepromotes trendy clouds and Wi-Fi architecture without controllers, with centralized management of the entire infrastructure. And here the clouds, you ask. Everything is very simple: the Wi-Fi network management system is now located in the cloud, supported by Aerohive. Those. all the worries about installing and operating the server and the software that manages the network are taken over by the hardware manufacturer. You just have to connect the access points to the network. They themselves will find the cloud on the Internet, register and be ready to manage from the central "cloud" console, which you can access through any browser. As for architecture without controllers ( Cooperative Control Architecture), then it will allow you to remove the “bottlenecks” characteristic of traditional Wi-Fi networks with controllers. Aerohive access points are their own controllers, self-organizing in the "honeycomb".

    Atheros , the leading provider of access point chipsets, recently acquired by Qualcomm , is starting to ship chipsets with three MIMO streams that deliver up to 450 Mbps transmission speeds. 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, without "spraying" it in places where there are currently no customers.

    Why do I need TamoGraph


    All this iron splendor will work as it should under only one condition: the network must be properly planned, deployed, and tested. Your ideas and the equipment manufacturer’s ideas will shatter about the harsh reality, if, for example, you don’t take into account the fact that in a nearby office, right behind a thin wall, there’s a 200-milliwatt access point on channel 6 with a dipole antenna that clogs you with all the available radio spectrum with its signal. To avoid errors, it is necessary to conduct network inspections at the stage before and after deployment.

    Inspection, i.e. Wi-Fi network characteristics are collected, visualized and analyzed using special software such as TamoGraph Site Survey , which is produced by our Tamosoft company. We have two serious competitors from AirMagnet and Ekahau , and there are also some simpler free programs. Further examples will be based on TamoGraph, as a closer and more familiar program to me. In addition, as far as I know, only our company is actively promoting this product in Russia, has released a fully localized Russian version and accepts payment in a convenient form (Softkey, WebMoney, etc.), while AirMagnet and Ekahau do not focus on Russia.

    TamoGraph Office Survey

    Having installed TamoGraph on the laptop and having imported the plan of the room or area, the engineer bypasses the room, marking his current position on the plan (or even circling the open space, say the campus, on a bicycle, while the GPS receiver can automatically mark the current position).

    TamoGraph GPS Survey

    By collecting data, the program can build a lot of useful visualizations that can help you find problems that can affect network performance and coverage: signal level in the 2.4 and 5 GHz bands, interference level from other networks, expected data transfer rate, compliance with specified requirements, etc. . Having documented the result with the help of a report that is easily generated directly in the program, based on the data obtained, you can adjust the network: change frequencies, change antenna types, move, remove or add access points, and so on.

    TamoGraph Results

    Summing up, we can say that today, building 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 Wi-Fi networks, get started. And of course, do not neglect the specialized, neutral in relation to the manufacturers of hardware and software, training and certification, such as CWNP . Your Wi-Fi training is the key to success.

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