4G Cellular Technology Progress - 4G Network

With the introduction of 1G in 1982, 2G in 1992 and 3G around 2004, the deployment of 4G Cellular Technology progress some time around 2014–2018 might look like a fairly certain bet. In the last few years there has been much discussion around 4G, with conferences and books published. Some thought that it was appropriate to start discussion of 4G cellular system in 2002 given the likely ten years it would take to complete the standard and have equipment developed. An example of this was the Japanese authorities who announced a research program aimed at producing a system capable of delivering 100 Mbits/s to end users. Others argued that 3G had failed, or was inappropriate, and 4G should be introduced rapidly in its place.

As might be expected, some of the key proponents of a rapid introduction of 4G were manufacturers with product that they classified as being 4G cellular system. However, during the early part of 2003, the ITU, mindful perhaps of the slow and somewhat uncertain introduction of 3G, decided to put on hold any discussions about 4G systems, thus delaying the introduction of 4G network to a date of 2015, if not later.

Broadly, higher data rates require more spectrum. More spectrum can only be found higher in the frequency band but higher frequency signals have a lower propagation range. Each generation has accepted a shorter range in return for a higher data rate. Indeed, interestingly, the Japanese plans for a 4G cellular technology talk of an OFDM-based solution in the 3–6 GHz band providing up to 100 Mbits/s of data. This is almost identical to the specification for the latest W-LAN system, 802.11a, which is already available and exceeded by proposals for 802.11n.

Higher data rate systems are preferred but with their shorter range can be economically deployed only in high-density areas. So we might expect a network where 2G is used to cover rural areas, 3G to cover urban and suburban areas along with key transport corridors, and W-LANs providing very high data rates in selected ‘hotspot’ locations such as airports.

This has data rates in the region of 1–2 Mbits/s at present, much lower than the rate that the W-LAN air interface can provide. A further increase in air interface data rate in such a situation is pointless. Instead, research needs to be focused on better types of backhaul.

Hence, an argument that will continue to be developed in subsequent chapters is there may not be another generation of 4g cellular technology because there may not be sufficient economic justification for the development of a completely new standard. Instead, we might expect to see enhancements to all the different standards making up the complete communications network, with perhaps some new niche standards emerging in areas such as ultra-short range communications. This has not stopped some claiming that they already have a 4G technology, or like the Japanese, that they are working on one. Of course, since there is no widely agreed definition of what comprises a new generation, anyone is free to claim that their technology meets whatever criteria they regard as important, and with the definition of 3G already confused, perhaps we should expect 4G network to be even more opaque!