Mobile Communications Technology Overview

Wi-Fi® – Is a certification mark developed by the Wi-Fi Alliance to indicate that wireless local area network (WLAN) products are based on the Institute of Electrical and Electronics Engineers’ (IEEE) 802.11 standards. Wi-Fi® has become somewhat misappropriated to refer to all wireless local area network technologies in the same way as Kleenex® is used to erroneously refer to all facial tissue or Xerox® is used to refer to the process of copying documents. Unless specifically referring to a device bearing some form of the Wi-Fi® mark, the correct generic term is “Wireless LAN” (WLAN) or “Wireless Connectivity.” For those of you that are old enough, “The Wireless” was the newfangled term for the Radio or any form of Radio Transmission Broadcast and Receiver.

In the same manner, in order to connect a wireless local area network enabled device (i.e. notebook computer with WLAN card) to a wired local area network, there needs to be a Wireless Access Point (WAP).  A Wireless Access Point simply adds a wireless antenna to a wired local area network and electronically transforms the connection from wired to wireless while maintaining all other characteristics of the network configuration.

Conversely, if no wired local area network exists, a Wireless Router can connect directly to an Internet Modem (i.e. Cable Modem or xDSL Modem) and translate as well as “route” (think play traffic cop) between the single connection provided by the Internet Service Provider (i.e. Verizon xDSL, FiOS, Time Warner Cable, Cox Cable, Cablevision, Etc.) and the multiple Wireless Enabled Devices in your office or home. (i.e. Again any WLAN card enabled computer, digital video recorder like Tivo®, Blu- Ray DVD player, XBox® gaming device or Wi-Fi® enabled Cell phone.) Note: A “Wired Router” does exactly the same thing as a wireless enabled router except that it uses RJ-45 Ethernet cables to make the connections between all devices instead of relying on Wireless technology. Some Routers offer both “Wired” and “Wireless” connectivity options.

Many commercial establishments and public spaces offer free Wi-Fi® a.k.a. HotSpot Wireless LAN connectivity as a courtesy. These include transportation centers, parks, restaurants, rest stops, hotels, and shopping malls. In the past many establishments charged for WLAN access but now provide it free of charge as an incentive to visit their locations. Virtually all of these public HotSpots require the user to accept a “terms of use” agreement which in short generally states that the WLAN Service is offered as a convenience on a where-is, as-is basis with zero liability to the provider and a pledge by the user to only use the service for lawful purposes. These are what are known as “click-through” agreements that usually require one to enter their name, possibly email address, and click, “I accept.” The provider may capture the IP Address and/or Media Access Control (MAC) address of the device being used to access their network. The MAC address is like a social security number for any network enabled device – no two units should have the same one.

It is important to understand that these are PUBLIC, insecure networks that place your computer, smart- phone, or tablet computer directly on the Internet with no front door security or Firewall of any kind. For any kind of notebook or desktop computer that will be connected via a PUBLIC HotSpot (or directly connected to a cable or xDSL modem without a Router in place), it is imperative that the Firewall feature of the respective operating system be “turned on and active.” Both Windows and Apple computers include basic Firewall capabilities as part of their operating system software.

As most Tablet computers and Smart-Phones do not contain any significant amount of stored sensitive data, but are viewed primarily as “consumption only” devices, they are less of a target by hackers – people that want to illegally obtain data from these devices. This is slowly changing and Firewall applications are being developed for these platforms to protect them.

Cellular Data Cards and devices that have Embedded Cellular Data Card technology also provide “Wireless” Internet connectivity except they use a different technology based on predominantly CDMA EV-DO (Code Division Multiple Access – Evolution Data Optimized) or EDGE-GSM (Enhanced Data Rates for GSM – Global System for Mobile Communications) which are generally referred to as “3G” (Third Generation) technologies or LTE (Long Term Evolution) and HSPA+ (Evolved High-Speed Packet Access) which are generally referred to as “4G.” (4th Generation). These devices connect directly to the major US Cellular Carrier data networks as available from Verizon Wireless, Sprint, AT&T, TMobile, MetroPCS, and Virgin Mobile. In terms of functionality, they are exactly like a cell phone that carries voice communications, except they carry packets of data instead – with all of the same benefits and pitfalls. A strong signal, i.e. more “bars” will provide better throughput of data. No “bars” means no signal, and therefore, no cellular data service. These devices usually provide access for the one specific device to which they are attached or embedded. In some cases, a computer which has an attached Cellular Data Card can be transformed in to a Wireless Cellular Data Router so that other Wireless LAN (WLAN) enabled devices can “share” the Cellular Data Internet Connection provided by the host device.

A MiFi® refers specifically to a line of wireless routers manufactured by Novatel Wireless, rebranded by the major Cellular Carriers (Verizon Wireless, Sprint, AT&T) that contain embedded cellular data card technology and allow for multiple, usually up to five maximum, WiFi® (Wireless LAN enabled) devices to connect to the Internet. The more generic term is “Cellular Data HotSpot.” Similar cellular enabled wireless routers have started to appear from other manufacturers. These devices can be 3G or 4G and speeds vary with the specific cellular data coverage available in a given area by the Cellular Carrier.

Smart-Phones have embedded cellular data card technology separate and apart from their ability to be used as regular cellular phones. In most cases, the data plan to enable Internet access for the Smart- Phone is an additional charge above and beyond the voice minutes plan. Some Smart-Phones have the capability to act as a “Cellular Data Hotspot” in a manner exactly as described above with the same five Wireless LAN (WLAN) enabled device connection limit. The other significant limitation is that the Carrier does NOT provide any additional data allowance for the additional fee. Any WLAN devices just deplete the monthly data allowance more quickly.

References for more information:
Wi-Fi® Standard – http://en.wikipedia.org/wiki/Wi-Fi
Wi-Fi® Alliance – http://www.wi-fi.org
MiFi® Standard – http://en.wikipedia.org/wiki/Mifi
Novatel MiFi®  – http://www.nvtl.com/
Cellular Data Standards:  http://en.wikipedia.org/wiki/Comparison_of_wireless_data_standards

Cellular Data Card Carrier Sites:
Verizon Wireless – http://www.verizonwireless.com/b2c/explore/?page=mobile-hotspots
Sprint – http://ria.sprint.com/ria/pages/index.jsp?ms=4G&INTNA V=A TG:HE:4G#!/devices/mifi
AT&T – http://www.wireless.att.com/cell-phone-service/specials/netbooks.jsp
Virgin Mobile – http://www.virginmobileusa.com/mobile-broadband/mifi-2200.html