Are you at a coffee shop and your laptop is not displaying the coffee shop’s Wi-Fi network, but your phone is? Well, same thing happened to me today (12/30/2017). I’m using an Acer laptop, with pretty good tech specs, but the Wi-Fi specs, I guess not too good, for only one reason. My laptop is not compatible with 5GHz Wi-Fi channels. The coffee shop I am in only offers one 5GHz Wi-Fi frequency. What does this all mean bro? Well, for a very long time, the default and most used Wi-Fi frequency has been 2.4GHz. Lately though, like during the past 3-4 years, 5GHz Wi-Fi channels have been growing in popularity. Usually, most network devices that contain a 5GHz channel Wi-Fi emitter/receiver also contain a 2.4GHz Wi-Fi emitter/receiver. So, what’s the purpose of 5GHz functionality in a Wi-Fi router? The main purpose of having a dual band Wi-Fi router containing both 2.4Ghz and 5GHz band frequencies is to divert traffic (incoming and outgoing internet requests by your devices connected in your Wi-Fi network) into two different channels of the same network. And what’s the point of having two different frequencies in the same Wi-Fi network? The point is to reduce the clog of internet traffic of too much devices running on the same frequency. So think of it like this: You know when you’re in the freeway and it’s packed? At those times you wish there was an extra lane in the freeway, so that traffic would not be so bad and slow. Well like in streets and traffic, when you add an extra frequency in a network, you are metaphorically adding another “lane” to the Wi-Fi network. This way, when you connect a device to your Wi-Fi network like your phone or laptop, you have the option to choose which frequency to connect to, the 2.4GHz or the 5GHz frequency. This reduces the bottleneck of having too many devices connected to the same Wi-Fi frequency which slows down internet speed for the devices connected to the Wi-Fi network. Wi-Fi emmitters and receivers use a protocol technology called CSMA/CA which stands for Carrier Sense Multiple Access with Collision Avoidance. This network protocol assures that all devices connected to a Wi-Fi network receive the correct data and not data meant for a different device than the device intended (For example, your Smartphone receives the download that you initiated in your laptop, for your laptop). One of the main tactics that CSMA/CA uses in order to avoid such data collisions is that only one device can speak to the router at a time per radio-frequency. This means that if you have 8 devices in your Wi-Fi network in the 2.4GHz Wi-Fi frequency, your Wi-Fi is going to be a lot slower, than say if you only had 4 devices in that frequency instead, since your router can only talk to each device one at a time. But if you had two frequencies available in your Wi-Fi router (2 radio frequencies does not mean 2 networks, just 2 frequencies within the same network), then 4 devices could be on the 2.4GHz frequency and the other two devices could connect to the 5GHz frequency. This way, your Wi-Fi can, in other words simultaneously talk to 2 devices at any given time, since CSMA/CA is in regards to frequencies, so now your router is twice as fast! So, if your coffee shop does not have a router capable of, or has turned off dual-band capabilities, it might be good to advise them to consider making the change to a dual-band router.
Anyways, if for some reason you are not able to see your device on the network, it good to verify the Wi-Fi chip-set capabilities of your device. If you are on a Windows device, open up CMD and type in “netsh wlan show drivers”, then press enter. You might see something similar to the following:
C:\Users\user1>netsh wlan show drivers Interface name: Wi-Fi Driver : Qualcomm Atheros AR9485WB-EG Wireless Network Adapter Vendor : Qualcomm Atheros Communications Inc. Provider : Microsoft Date : 3/26/2016 Version : 220.127.116.11 INF file : athw8x.inf Type : Native Wi-Fi Driver Radio types supported : 802.11b 802.11g 802.11n FIPS 140-2 mode supported : Yes 802.11w Management Frame Protection supported : Yes Hosted network supported : Yes Authentication and cipher supported in infrastructure mode: Open None Open WEP-40bit Open WEP-104bit Open WEP WPA-Enterprise TKIP WPA-Personal TKIP WPA2-Enterprise TKIP WPA2-Personal TKIP Vendor defined TKIP WPA2-Enterprise Vendor defined Vendor defined Vendor defined WPA-Enterprise CCMP WPA-Personal CCMP WPA2-Enterprise CCMP Vendor defined CCMP WPA2-Enterprise Vendor defined Vendor defined Vendor defined WPA2-Personal CCMP Vendor defined Vendor defined Authentication and cipher supported in ad-hoc mode: Open None Open WEP-40bit Open WEP-104bit Open WEP WPA2-Personal CCMP Vendor defined Vendor defined Wireless Display Supported: Yes (Graphics Driver: Yes, Wi-Fi Driver: Yes) C:\Users\user1> </code></pre> The data we are looking for from the above output is “Radio types supported”. As you can see, from my example, mines is:
Radio types supported : 802.11b 802.11g 802.11n
Now, since Wi-Fi was first released, the official name of the Wi-Fi technology is called “802.11”. The letters that come after the “802.11” are the version releases of every new Wi-Fi update. The main Wi-Fi releases in sequence are the following, in order from first to latest: 802.11a -> 802.11b -> 802.11g -> 802.11n -> 802.11ac. So if you look at my sample radio type supported again, you can observe that my latest supported Wi-Fi version in my device (It’s a laptop) is 802.11n. Now, 802.11n chip-sets come in a variety of frequencies. These are, 2.4GHz, 5GHz, or both 2.4GHz/5GHz chip sets. Unfortunately, my laptop only came with 2.4GHz frequency capability. How do I know? Because every Wi-Fi network that I have ever connect the this laptop to can only detect 2.4GHz frequencies, even if the router offered 5GHz connections. On a different note, if you have 802.11ac, your pretty damn lucky! These chip sets all come with 2.4GHz/5GHz Wi-Fi capabilities, and are completely backwards compatible with all 802.11 Wi-Fi versions.
Ok, so let’s suppose that you only have an 802.11 version that only allows 2GHz connections, but the Wi-Fi network that you are in only supports 5GHz connections (as it happened to me). How can you still make use of that 5GHz Wi-Fi with your non 5GHz compatible device? Read the question below, and if you answer to it is yes, then continue to the solution!
Question: Does your Smartphone pickup the Wi-Fi there?
Solution: If yes, then this means that you can use your phone as a network and transfer the coffee shop’s Wi-Fi from your smartphone to your other device (probably a laptop). You can either use Bluetooth or USB tethering from your phone to your laptop make your smartphone the network fr your other device.