Wi-Fi Basics

                 Wireless networking make use of short range radio waves substituting the cables in a LAN. The Wi-Fi networks are based on the IEEE 802.11 standards. The other types of wireless communication includes 3G, 4G, and Bluetooth etc. Today almost all laptops, mobile phones, tablets etc. having the wireless interface built into it. The wireless communications can be either in infrastructure mode or ad-hoc mode. In infrastructure mode we uses a wireless Access Point (AP) to connect all these device. So the members of the Wi-Fi network communicate only through the AP. But in ad-hoc mode, devices can communicate directly over Wi-Fi without an AP. The first thing we will do with an AP is setup a Service Set Identifier (SSID). SSID is the wireless network name broadcast. The Wi-Fi networks uses 2 different bands, the 2.4 GHz and the 5 GHz. The 2.4 GHz has 14 channels with 3 non overlapping channels and 5 GHz having 24 non overlapping channels. The 5 GHz band provides faster connection with less interference, but for a small range. The 2.4 GHz has greater range, but with more interference.

      Let us discuss only the popular 802.11 wireless standards.

802.11a: Operating in 5GHz band and having bandwidth rate up to 54Mbps.

802.11b: Introduced in 1999 and Operating in 2.4GHz band and having bandwidth rate up to 11Mbps.

802.11g: Operating in 2.4GHz band and having bandwidth rate up to 54Mbps.

802.11n: Operating in 2.4GHz and 5GHz band and having bandwidth rate up to 600Mbps. They have multiple antennas and a communication protocol called Multiple In – Multiple Out to provide duplex communication.

802.11ac:  Operating in 5 GHz band and getting bandwidth up to 1Gbps.

Bandwidth vs Throughput

             Bandwidth is the theoretical data-transfer rate possible. The data transfer rate is measured in bits per second. Throughput is the actual data transfer rate after interference is taken into account.

                     You can check the latency, download and upload speed by http://www.speedtest.net/ 

 Ping is used to calculate the latency. Download speed indicates the data rate at which you are receiving and upload speed indicates the data rate at which you are sending data. It will also shows the Public IP and the ISP providing the internet service to you.

Wireless Security

  Security is important to protect our wireless network from intruders. Unauthorized connections slowdown your connection and also can access your shared files. Current Wi-Fi password encryption supports 8-64 characters and can include numbers, symbols, upper and lower case characters. Let us discuss the different wireless security encryption protocols.

1.   Web Encryption Protocol (WEP): It was the first encryption protocol and it was not strong enough to protect the data. It uses 8 character passwords. Use 128 bit encryption to provide strong protection.

2.   Wi-Fi Protected Access (WPA): It was introduced in 2003 to cover the issues with WEP. But not that much effective.

3.   WPA2: It provides stronger encryption. It has two encryption methods the Pre Shared Key (PSK) encryption and Enterprise (ENT) encryption. It supports up to 64 character password.

      Other than the encryption methods for security you can disable the SSID broadcast in case if you want hide the network from others. But in that case you have to manually configure the Wi-Fi settings for each client.

 Another thing you can do is the MAC address filtering. Most of the broadband routers and APs provides the MAC address filtering. So you can configure them to either accept only particular MAC addresses or reject particular MAC addresses.

Also you can limit the DHCP leased addresses to reduce the number of clients.

 The most important thing is to change the management password for the broadband router or AP from the default one. 

Things to consider while setup Wi-Fi Network

       The first thing you need to check the proper place to fix the APs. You have to do a site survey as per the needs. There are lot of software available to do the site survey. inSSIDer is one of the best, site survey tool.

It will show you the signal strength and if any neighboring SSIDs use the same channel encryption method used etc.  -30dBm is the maximum achievable signal strength and the client should be a few feet from the AP to get this. -70dBm is the minimum signal strength required for reliable packet delivery. 

       Another thing you can do is to replace the builtin antenna with antennas that are enhanced, giving you better range and performance. You can check the router vendor website for the supporting enhanced antennas. Also you can use wireless repeaters between the AP and less coverage area.