RAATS WIFI




Wi-Fi is a Passion

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Client and application planning



The design is based around the clients that need to connect to the wireless network. Most of the time, you do not have influence of the clients that are connecting to your network. You need to design the network for the ‘weakest’ client, but what kind of clients can be part of your network?

Laptops
Laptops are typically the strongest in your network—they have their own Wi-Fi adapters and support most of the time multiple streams. A MacBook Pro has a 3x3 802.11ac chipset, but at this point most laptops supports only 2 streams. There are even clients that support 2.4 GHz only. So, there are a lot of laptop types on the market with all different kinds of features in their wireless chipset. Not all clients support all the channels. For example, laptops from the States will probably not work on channel 13 in the 2.4 GHz band or all the 5 GHz band channels. Same for the channel bounding, 40 MHz, 80 MHz or 160 MHz channels.

When you work with laptops as client, take into consideration what type of EAP and PHY they support. How many are they deploying, are they stationary or moving a lot. The last part is important for picking the right roaming mechanism.

Tablets
Tablets are in most organisations nice replacers for laptops; however, they are less powerful when it comes to wireless. For the reason of conserving battery power, most tablets are only single-stream devices. The same considerations need to be taken for tablets as for laptops, for example EAP and PHY support.

Mobile phones
Mobile phones are comparable to tablets, single-stream devices. In that case the same considerations as tablets are in place for mobile devices.

802.11 VoIP handsets
VoIP handsets are used in different types of industries and are using the wireless network. They have more features than normal mobile phones, such as IP assignment, VLAN support, security features of WPA2 PSK, and so on. Important requirements are roaming support, Quality of Service, and VoIP protocols.

Wireless desktops
Desktops are most of the time connected through a cable, but it is sometimes a high expense to have cables throughout the company. For that reason, there are Wi-Fi adapters for non-movable desktops. It is important to think where the antenna is placed. Sometimes they are placed behind the desktop under the desk, which is not helping with the signal propagation.

Internet of things
Internet of things (IoT) are devices that communicate with each other over the wireless network. There are tracking devices, but also devices for things like sharing information about temperatures of fridges and freezers throughout the company. They a transmit small amount of data, but frequently.

Those clients are not just sitting there in your network. There are different types of applications ran on the devices that have their own requirements and demands of the wireless network. For application planning we need to know what is the size that an average communication transmits, how many communications are per minute, and how many clients are using this application?

Web based
Web based applications are HTTP or HTTPS based applications with sometimes special plug-ins that are required.

Mobile apps
These are apps that you need to download from the app store for your mobile device (phone or tablet). In these apps can be ads that are blocked by the firewall, and the apps need frequently updated.

Real-time
Real-time applications are applications that use both voice and video, for example Voice over IP, video conferencing, and streaming. The issue with real time applications is that packages can become out of order when you resend them. This can change the order of a movie or phone call, for example.

Audio and video can be encoded with different types of algorithms.
H.261 is for video over ISDN lines
H.264 known for MPEG-4, video encoding, HDTV, VoIP
G.711 audio encoding at 64 Kbps
G.722 audio encoding at 64, 56 and 48 Kbps
G.723/723.1 audio encoding at 5.4 and 6.3 Kbps
G.729/729A audio encoding at 8 Kbps and removes the silence before encoding.

High-Date Volume applications
Those applications transmit every hour more than a few megabytes. For example, the app store or Windows update that update a couple apps/applications at a time, and this can be a couple gigabytes.