WWAN Introduction [2]: Radio Frequency #ABuyingGuide

The mobile network utilizes a licensed radio frequency to provision the service, unlike WiFi which runs on 2.4GHz and 5GHz unlicensed bands, WWAN needs to support a wide range of frequencies to meet the mobile network operators requirement, network operators across the globe deploy the radio network on the frequency regulated by the authorities i.e. country, region, etc. Because of such politics, the WWAN card you purchase on ebay from the US may not work in Asia or Europe or vice versa, even they may claim the card supports LTE radio. What makes this complexity worse is the different radio technologies (4G, 3G, 2G) each has their own set of frequencies, selecting the right card to work on the mobile network in your country can be a daunting job.

Here is an illustration of the Radio Frequency vs Radio Technology:

The WWAN industry uses "band" to refer to the radio frequency, it goes like Band1, Band2, Band3, …, to represent each of the particular frequencies. Thanks to Wikipedia, there is a Wiki page that summarizes the frequency bands in a table for quick lookup:

http://en.wikipedia.org/wiki/E-UTRA#Frequency_bands_and_channel_bandwidths

and a list of the 4G LTE networks:

http://en.wikipedia.org/wiki/List_of_LTE_networks

3G networks:

http://en.wikipedia.org/wiki/List_of_UMTS_networks

With the Wiki lookup tables above, you could easily select what radio frequency you need to have on your WWAN card to support the mobile operator in your country!

Here are the questions to ask when you approach a seller:

- What 4G LTE band do you support?

- What 3G band do you support?

- What 2G* band do you support?

* This is probably not needed, 2G is way too slow for a good Mobile Broadband experience.