Ever since the first commercial mobile networks were launched in the 1980s, the demand for ever-improving and more efficient mobile communication has spurred on better technology within this arena. The network relies on communication via radio waves to allow mobile devices to communicate with each other.
The central component of any cellular network is the cellular base, which is essentially a fixed transceiver over a particular parcel of land. A transceiver is a device that has both a transmitter (broadcasts radio waves) and a receiver (interprets radio waves) where these two components are generally contained within the same device and sometimes share the same circuitry. The shape of the cell is hexagonal because this geometric form, which strongly resembles a beehive, allows for a practical way to cover an area without gaps and overlaps of the circular cells. A key subcomponent of the cellular base is the Mobile Telephone Switching Office (MTSO), which is responsible for linking communications between mobile devices and, in the event of a significant decrease in reception (i.e. due to distance from a cellular base), will switch the connection to a more suitable base. 
Of course, the component of a cellular network that is the most visible to the user is the mobile unit. A mobile unit is basically a miniature cellular base that contains its own transmitter, receiver, and antenna. The phone communicates with the cellular base via a cell-site controller, which is responsible for managing the channel assignments, receiving outgoing call data from the mobile units, and paging mobile units. 
Global System for Mobile Communication (GSM) is a standard for describing the technologies associated with a given version of a digital cellular network. As it is a cellular network, mobile devices can connect to version of GSM and receive or send calls. The household terms for some GSM standards are 2G (i.e. second generation network), and 3G (i.e. the third generation network). GSM was perhaps the most popular of all the 2G mobile network technologies as it accounted for 66% of the 2G market in 2002. 
The bottleneck resource in a wireless network is frequency spectrum. Frequency spectrum is a limited good and even though it is technically accessible for the public to use, authorization to broadcast on a given frequency is controlled and limited. Thus, mobile networks pay exorbitant fees for the license to broadcast at a certain frequency and cellular network design places heavy emphasis around the efficient use of the available network frequency.
The reusability of the frequency is dependent upon the application, with similar applications receiving a similar frequency for use. It is known that wavelengths that travel with a greater frequency (or a shorter wavelength) produce stronger communication lines. Unfortunately, the variability of the radio channel with frequency of signal is unpredictable because it is heavily dependent on man-made and natural factors; for instance, temperature, distance between cellular base and mobile device, and the environment are influencing factors. 
It seems that the pace of mobile technology might be too much for the network capacity to handle in the future. The future and fast 4G networks will allow users to effortlessly stream much more data than in the past so as to support expensive Internet applications and services. Some users have been consuming much more than their "fair share" of the limited public resource that network capacity represents. In fact, certain wireless carriers have begun to impose additional fees for users who send and receive significantly more data. Mark Siegel, an AT&T spokesman, suggests that current trends in cellular data usage would lead to "the company's network [carrying] more data in the first two months of 2015 than in all of 2010." 
While unlimited data plans see thrilling and delightful, they are simply a thing of the past due to the reality of limited network resources. Until such a time as network technology can catch up with the increasing data-driven appetite of mobile devices and their users, tiered data plans might be the best way for wireless providers to distribute their network capacity in a fair and financially viable model.
© Justin Lee. The author grants permission to copy, distribute and display this work in unaltered form, with attribution to the author, for noncommercial purposes only. All other rights, including commercial rights, are reserved to the author.
 J. H. Green, The Irwin Handbook of Telecommunications, 5th Ed., (McGraw-Hill, 2006).
 S. Kasera, N. Narang and A. P. Priyanka, 2.5 G Mobile Networks: CPRS and EDGE (McGraw-Hill, 2009), pp. 5.
 A. Ahmad, Wireless and Mobile Data Networks (Wiley, 2005), pp. 14-15.
 J. Wortham, "As Networks Speed Up, Data Hits a Wall," New York Times, 14 Aug 11.