4G or fourth generation wireless doesn’t have a strict definition, but it is roughly stated as the bandwidth typical of Cable broadband or Ethernet over Copper business connections. With this level of transmission speed and a city-wide reach, 4G wireless can take over service for desktop as well as mobile devices.One might throw WiFi into the 4G category. The bandwidth for a, b, g, and n WiFi technologies fall into the right bandwidth category. However, WiFi is a short distance system. It works well within and nearby particular locations, such as homes, offices, restaurants, hotels, airports and even park benches. But you can’t get in your car and drive away with a WiFi connection. It will disappear as soon as you leave the parking lot. In a way, WiFi is more of a PAN or Personal Area Network like Bluetooth.
The higher power wireless technologies, including 2G & 3G are associated with cellular phone service. These are based on using networks of fixed transmitters and receivers arranged as cells with signals that fill-in the coverage between towers. The trick of turning this system into a metropolitan or wide area network is to coordinate the handoff of an existing wireless connection as the user moves from cell to cell.
The most popular wireless technology right now is 3G. It offers bandwidths similar to T1 lines and basic DSL of around 1.5 Mbps on average in metropolitan areas. You may get two or more times this speed if you happen to be near a tower with few users. This is more than adequate for many mobile uses, such as Web browsing, email and viewing video clips on smartphone screens.
Beyond limited speed, 3G also suffers from limited bandwidth availability. It shares channels with cellular telephone on the same towers. Those channels were originally sized to support expected voice traffic. They’ve been overwhelmed by the higher bandwidth requirements of Internet data traffic. That’s why carriers are so insistent on bandwidth caps.
There are a couple of different approaches to 4G wireless. The one taken by the cell phone companies is to view 4G as an upgrade to their 3G systems. There are two differing cellular system that co-exist. One is a US-centric system called CDMA that is used by Verizon, Sprint and others. The other is a more global standard called GSM that is used by AT&T and T-Mobile.
Right now, AT&T and T-Mobile have upgraded their 3G networks to a faster version of the same thing called HSPA+ that delivers up to 6 to 8 Mbps. Verizon has moved to a 4G technology called LTE that offers downloads of 5 to 12 Mbps. Sprint has gone with another 4G technology called WiMAX that delivers downloads in the 3 to 6 Mbps speed range.
As wireless continues to evolve, 4G is expected to move into two camps. LTE is the technology most discussed as a truly universal standard. WiMAX deployment actually predated LTE and has installations worldwide. Both LTE and WiMAX have technical upgrade paths that can boost download speeds to over 100 Mbps and even 1000 Mbps. This is competitive with many fiber services and ensures that 4G wireless will be with us for a long time.
One thing we’re also seeing with 4G wireless is the use of lower frequency bands that can more easily penetrate buildings. These bands came from the re-deployment of those channels from UHF TV as part of a federal auction. Clear offers 4G fixed and mobile wireless service with a telephone option over WiMAX in over 80 cities nationwide. Right now, this service offers unlimited broadband service.
