Definition and Features

• The most important thing to realize is that 4G is a work in progress--no set standards are laid out for it yet, and organizations charged with standards and regulations anticipate commercial launch between 2012 and 2015. Furthermore, currently no manufacturer produces smart phones capable of 4G. However, 4G champions trumpet capability to transmit voice, data and multimedia in real time anywhere, at 10 times the speed of the current 3G network. In short, 4G will allow people wireless Internet connectivity with the same ease and ubiquity as we currently have with cell phone service, if not better.
  
  

History

• To gain some perspective, it helps to understand the previous and current generations of wireless communications. The first generation, 1G, was the wireless analog "bag phones" of the 1980s that looked a little like military walkie-talkies. The second generation was more of a revolution. 2G replaced analog with digital, and established the Global System of Mobile communications (GSM) protocol in the early 1990s that operates via Time Division Multiple Access (TDMA), which divides a radio frequency into discrete time periods, then assigns those slots to different calls, so a carrier can funnel calls across the same frequency at the same time. Finland led the GSM charge with its commercial network. 3G, first launched commercially by NTT DoMoCo of Japan in the fall of 2001, dramatically increased transmission speed and network capacity of data as well as voice.
  
  

A High-Tech Horse Race

• The future of 4G could be settled in large part on the winner of a race between three competing technologies. The appropriately named Long-Term Evolution (LTE) technology builds on the current GSM system using TDMA, while another popular format gaining traction is WiMAX or mobile broadband, the popular name for the specification proposed by the Institute of Electrical and Electronics Engineers (IEEE) 802.16, which allows a fixed point to broadcast to multiple points up to 30 miles away and can transmit Internet, VoIP, voice and data. The dark horse is the Ultra Mobile Broadband (UMB), based on Code-Division Multiple Access (CDMA) that does not limit itself to specific frequencies like TDMA, but assigns digital sequence codes to the calls, letting more traffic get through the same overall bandwidth than TDMA can.
  
  

Players

• The major networks have staked different claims. Sprint, running on Clearwire's networks, has bet on WiMAX, and has a considerable lead in the market, operating in nearly 30 cities. Verizon has released plans to roll out its network using LTE in 25 to 30 cities by the end of 2010. AT&T and T-Mobile so far seems to be focusing on fine-tuning the delivery speed of its 3G network with a software upgrade, rather than racing toward the next generation.
  
  

Limitations/Considerations

• The first thing to consider is market timing. As noted above, experts don't expect a full-scale, nationwide commercial deployment before 2012; 2015 seems more likely. Furthermore, full-scale adoption will take years after the initial launch for significant impact on the way people interact. This may prove fortuitous, to help solve two bigger problems. First, the current 3G network has a spectrum shortage. With each telecommunications carrier in each country operating on different sections of the bandwidth spectrum, there's little or no bandwidth left to grow the overall network as more people enter the market for mobile voice and data communications worldwide. Second, no one cell phone, smart phone, or any other device (like an Apple iPad or Kindle) operates across carriers. If anything, 4G's extra capabilities may aggravate a problem people already wrestle with using 3G.